[since 1995]
41.
Bystranowska, Dominika; Stolarski, Jarosław; Ożyhar, Andrzej
Nucleobindin-2 as a potential modulator of biomineralization Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Nucleobindin-2 as a potential modulator of biomineralization},
author = {Dominika Bystranowska and Jarosław Stolarski and Andrzej Ożyhar},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Nucleobindin-2 (Nucb2) is a multifunctional calcium- and DNA-binding protein implicated in various physiological processes, including energy homeostasiss [1], stress response [2], and cancer progression [3, 4]. Structurally, Nucb2 contains EF-hand motifs that confer high affinity for divalent cations, particularly calcium (Ca²⁺), which is crucial for its conformational stability and biological activity [5]. In addition to Ca²⁺, Nucb2 can bind other metal ions such as zinc (Zn²⁺) and magnesium (Mg²⁺) [6], influencing its intracellular localization and interactions with molecular partners. Ion binding alters the secondary structure of the protein and may modulate its function in calcium-dependent signaling pathways. Recent studies suggest that Nucb2 possesses unique structural features—especially its EF-hand motifs and a putative acidic domain—that may implicate it in biomineralization processes. Biomineralization refers to the biologically controlled deposition of minerals, such as hydroxyapatite in bone or calcium carbonate in marine organisms, which requires tightly regulated ion transport and protein-mineral interactions. The ability of Nucb2 to bind Ca²⁺, Mg²⁺, and Zn²⁺ positions it as a potential modulator of mineral nucleation and growth. Its ion-induced conformational changes may facilitate the spatial organization of ions into stable nucleation sites or influence vesicular transport of mineral precursors. Furthermore, Nucb2 has been detected in tissues undergoing active mineralization, supporting its potential physiological relevance. Although direct evidence for the involvement of Nucb2 in mineral scaffolding remains limited, its structural parallels with other mineralization-associated proteins, such as osteopontin and calmodulin, suggest a possible regulatory function. Here, we present preliminary observations indicating that Nucb2 is involved in mineral-associated cellular processes, possibly through its interaction with divalent metal ions relevant to biomineral formation, and may directly regulate the morphology of the resulting calcium carbonate biocrystals....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Nucleobindin-2 (Nucb2) is a multifunctional calcium- and DNA-binding protein implicated in various physiological processes, including energy homeostasiss [1], stress response [2], and cancer progression [3, 4]. Structurally, Nucb2 contains EF-hand motifs that confer high affinity for divalent cations, particularly calcium (Ca²⁺), which is crucial for its conformational stability and biological activity [5]. In addition to Ca²⁺, Nucb2 can bind other metal ions such as zinc (Zn²⁺) and magnesium (Mg²⁺) [6], influencing its intracellular localization and interactions with molecular partners. Ion binding alters the secondary structure of the protein and may modulate its function in calcium-dependent signaling pathways. Recent studies suggest that Nucb2 possesses unique structural features—especially its EF-hand motifs and a putative acidic domain—that may implicate it in biomineralization processes. Biomineralization refers to the biologically controlled deposition of minerals, such as hydroxyapatite in bone or calcium carbonate in marine organisms, which requires tightly regulated ion transport and protein-mineral interactions. The ability of Nucb2 to bind Ca²⁺, Mg²⁺, and Zn²⁺ positions it as a potential modulator of mineral nucleation and growth. Its ion-induced conformational changes may facilitate the spatial organization of ions into stable nucleation sites or influence vesicular transport of mineral precursors. Furthermore, Nucb2 has been detected in tissues undergoing active mineralization, supporting its potential physiological relevance. Although direct evidence for the involvement of Nucb2 in mineral scaffolding remains limited, its structural parallels with other mineralization-associated proteins, such as osteopontin and calmodulin, suggest a possible regulatory function. Here, we present preliminary observations indicating that Nucb2 is involved in mineral-associated cellular processes, possibly through its interaction with divalent metal ions relevant to biomineral formation, and may directly regulate the morphology of the resulting calcium carbonate biocrystals....
42.
Zagrodzki, Maciej; Modrak-Wójcik, Anna; Łukaszewicz, Maciej
Insight into the oligomeric state of the Nudt12 NUDIX protein Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISBN: 2084-1892.
@conference{nokey,
title = {Insight into the oligomeric state of the Nudt12 NUDIX protein},
author = {Maciej Zagrodzki and Anna Modrak-Wójcik and Maciej Łukaszewicz},
isbn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Nudt12 is a member of the NUDIX protein superfamily that is characterized by a highly conserved NUDIX motif (GX5EX5[UA]XREX2EEXGU, where U is hydrophobic and X any amino acid). The glutamic acid residues within the NUDIX sequence REUXEE play role in the binding of divalent metal ions required for the catalytic activity of NUDIX enzymes [1]. Nudt12 was initially identified as NADH diphosphatase [2]. It hydrolyses also structures present on 5’ end of RNA (standard m7GpppN cap, and a “metabolite” cap structures as NAD or dpCoA [3, 4]), and is active towards a set of dinucleotide analogs of the standard mRNA cap structure, differing in methylation status of the initial guanosine and the type/methylation of the adjacent nucleotide [5, 6].
Human Nudt12 and its murine homologue are both dimeric proteins with 88% amino acid identity. Resolved crystal structures of hNudt12 and mNudt12 showed the presence of two distinct N- and C-terminal domains, and bound divalent metal ions (Mg2+ or Cd2+) in NUDIX motif [3, 7]. Dimerization of Nudt12 is essential for its catalytic activity and stability in vivo, as was demonstrated for the human protein: a designed monomeric mutant of hNudt12 was inactive in decapping assays [3].
The dimeric form of wild-type hNudt12 was confirmed in vitro by size exclusion chromatography (SEC) and analytical ultracentrifugation (AUC) [3]. However our initial AUC experiment for the murine protein mNudt12 showed a dimer-monomer equilibrium. Here, we report SEC analysis of mNudt12 oligomeric states under different experimental conditions (e.g. the presence of divalent ions or increasing protein concentration). Preliminary results confirmed the existence in solution dimeric forms of hNudt12, and a dimer-monomer equilibrium for mNudt12 that could be shifted in the presence of magnesium ions. As mentioned earlier, the monomeric form of hNudt12 is catalytically compromised; therefore, the influence of the oligomeric state of murine Nudt12 on its enzymatic activity and stability needs further investigation
.....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Nudt12 is a member of the NUDIX protein superfamily that is characterized by a highly conserved NUDIX motif (GX5EX5[UA]XREX2EEXGU, where U is hydrophobic and X any amino acid). The glutamic acid residues within the NUDIX sequence REUXEE play role in the binding of divalent metal ions required for the catalytic activity of NUDIX enzymes [1]. Nudt12 was initially identified as NADH diphosphatase [2]. It hydrolyses also structures present on 5’ end of RNA (standard m7GpppN cap, and a “metabolite” cap structures as NAD or dpCoA [3, 4]), and is active towards a set of dinucleotide analogs of the standard mRNA cap structure, differing in methylation status of the initial guanosine and the type/methylation of the adjacent nucleotide [5, 6].
Human Nudt12 and its murine homologue are both dimeric proteins with 88% amino acid identity. Resolved crystal structures of hNudt12 and mNudt12 showed the presence of two distinct N- and C-terminal domains, and bound divalent metal ions (Mg2+ or Cd2+) in NUDIX motif [3, 7]. Dimerization of Nudt12 is essential for its catalytic activity and stability in vivo, as was demonstrated for the human protein: a designed monomeric mutant of hNudt12 was inactive in decapping assays [3].
The dimeric form of wild-type hNudt12 was confirmed in vitro by size exclusion chromatography (SEC) and analytical ultracentrifugation (AUC) [3]. However our initial AUC experiment for the murine protein mNudt12 showed a dimer-monomer equilibrium. Here, we report SEC analysis of mNudt12 oligomeric states under different experimental conditions (e.g. the presence of divalent ions or increasing protein concentration). Preliminary results confirmed the existence in solution dimeric forms of hNudt12, and a dimer-monomer equilibrium for mNudt12 that could be shifted in the presence of magnesium ions. As mentioned earlier, the monomeric form of hNudt12 is catalytically compromised; therefore, the influence of the oligomeric state of murine Nudt12 on its enzymatic activity and stability needs further investigation
.....
Human Nudt12 and its murine homologue are both dimeric proteins with 88% amino acid identity. Resolved crystal structures of hNudt12 and mNudt12 showed the presence of two distinct N- and C-terminal domains, and bound divalent metal ions (Mg2+ or Cd2+) in NUDIX motif [3, 7]. Dimerization of Nudt12 is essential for its catalytic activity and stability in vivo, as was demonstrated for the human protein: a designed monomeric mutant of hNudt12 was inactive in decapping assays [3].
The dimeric form of wild-type hNudt12 was confirmed in vitro by size exclusion chromatography (SEC) and analytical ultracentrifugation (AUC) [3]. However our initial AUC experiment for the murine protein mNudt12 showed a dimer-monomer equilibrium. Here, we report SEC analysis of mNudt12 oligomeric states under different experimental conditions (e.g. the presence of divalent ions or increasing protein concentration). Preliminary results confirmed the existence in solution dimeric forms of hNudt12, and a dimer-monomer equilibrium for mNudt12 that could be shifted in the presence of magnesium ions. As mentioned earlier, the monomeric form of hNudt12 is catalytically compromised; therefore, the influence of the oligomeric state of murine Nudt12 on its enzymatic activity and stability needs further investigation
.....
43.
Raczyńska, Aneta; Żuberek, Joanna; Modrak-Wójcik, Anna
Cooperativity between the mRNA 5’cap and 4E-BP binding sites in eIF4E explored via tryptophan mutagenesis and fluorescence lifetime analysis Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Cooperativity between the mRNA 5’cap and 4E-BP binding sites in eIF4E explored via tryptophan mutagenesis and fluorescence lifetime analysis},
author = {Aneta Raczyńska and Joanna Żuberek and Anna Modrak-Wójcik},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Specific recognition of the mRNAs 5’ terminal cap structure by the eukaryotic initiation factor eIF4E is the first, rate-limiting, step in the cap-dependent translation [1]. Small 4E-binding proteins (4E-BP1, 4E-BP2, and 4E-BP3) inhibit the translation initiation process by competing with eIF4G initiation factor for the same binding site and by blocking the assembly of the translation machinery [1]. Although the cap and 4E-BP binding sites in eIF4E are spatially distant ( Fig. 1), they do not act independently. According to previous studies, the cap binding to eIF4E makes the affinity of eIF4E to 4E-BP1 significantly stronger, while binding of 4E-BP1 to the cap-eIF4E complex makes the cap dissociation slightly easier [2]. This finding indicates that the binding of either cap or 4E-BP1 induces conformational changes in eIF4E, not only in the region of a given binding site, but also in a distant region encompassing the binding site of the other ligand. ....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Specific recognition of the mRNAs 5’ terminal cap structure by the eukaryotic initiation factor eIF4E is the first, rate-limiting, step in the cap-dependent translation [1]. Small 4E-binding proteins (4E-BP1, 4E-BP2, and 4E-BP3) inhibit the translation initiation process by competing with eIF4G initiation factor for the same binding site and by blocking the assembly of the translation machinery [1]. Although the cap and 4E-BP binding sites in eIF4E are spatially distant ( Fig. 1), they do not act independently. According to previous studies, the cap binding to eIF4E makes the affinity of eIF4E to 4E-BP1 significantly stronger, while binding of 4E-BP1 to the cap-eIF4E complex makes the cap dissociation slightly easier [2]. This finding indicates that the binding of either cap or 4E-BP1 induces conformational changes in eIF4E, not only in the region of a given binding site, but also in a distant region encompassing the binding site of the other ligand. ....
44.
Stachurska-Korzeniowska, Karolina; Antosiewicz, Jan M.
Dependence of the fluorescence quantum yield of individual tryptophan residues in a protein on the excitation wavelength Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Dependence of the fluorescence quantum yield of individual tryptophan residues in a protein on the excitation wavelength},
author = {Karolina Stachurska-Korzeniowska and Jan M. Antosiewicz},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Sodium dodecyl sulfate (SDS) is an anionic surfactant that induces changes in both the secondary and tertiary structure of proteins. When examining such changes by fluorescence detection in the protein α-chymotrypsin, it was observed that the fluorescence of the protein, both in the presence and absence of SDS, depends not only on the presence of the surfactant itself but also on the excitation wavelength[1]. In the fluorescence spectrum measurements, a 320 nm cutoff filter was used, meaning that the detected protein fluorescence originated only from tryptophan residues.
Accordingly, a series of fluorescence spectrum measurements were carried out for both α-chymotrypsin and another protein, α-chymotrypsinogen, in the presence and absence of SDS, at four selected excitation wavelengths: 222, 260, 280, and 295 nm
We hypothesized that the fluorescence emission of individual tryptophan residues in the protein depends on the excitation wavelength. The fluorescence spectra of the proteins were analyzed according to a method found in the literature[2], where the authors presented fluorescence spectra as relative, normalized spectra: the curve for protein + SDS was subtracted from the curve for protein + buffer, and the resulting relative spectrum was then normalized at the short-wavelength minimum to –100 units. The obtained fluorescence spectra are presented in Figure 1. This way of presenting the spectra allows for the analysis of the total effect of the signal change compared to the initial value.
....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Sodium dodecyl sulfate (SDS) is an anionic surfactant that induces changes in both the secondary and tertiary structure of proteins. When examining such changes by fluorescence detection in the protein α-chymotrypsin, it was observed that the fluorescence of the protein, both in the presence and absence of SDS, depends not only on the presence of the surfactant itself but also on the excitation wavelength[1]. In the fluorescence spectrum measurements, a 320 nm cutoff filter was used, meaning that the detected protein fluorescence originated only from tryptophan residues.
Accordingly, a series of fluorescence spectrum measurements were carried out for both α-chymotrypsin and another protein, α-chymotrypsinogen, in the presence and absence of SDS, at four selected excitation wavelengths: 222, 260, 280, and 295 nm
We hypothesized that the fluorescence emission of individual tryptophan residues in the protein depends on the excitation wavelength. The fluorescence spectra of the proteins were analyzed according to a method found in the literature[2], where the authors presented fluorescence spectra as relative, normalized spectra: the curve for protein + SDS was subtracted from the curve for protein + buffer, and the resulting relative spectrum was then normalized at the short-wavelength minimum to –100 units. The obtained fluorescence spectra are presented in Figure 1. This way of presenting the spectra allows for the analysis of the total effect of the signal change compared to the initial value.
....
Accordingly, a series of fluorescence spectrum measurements were carried out for both α-chymotrypsin and another protein, α-chymotrypsinogen, in the presence and absence of SDS, at four selected excitation wavelengths: 222, 260, 280, and 295 nm
We hypothesized that the fluorescence emission of individual tryptophan residues in the protein depends on the excitation wavelength. The fluorescence spectra of the proteins were analyzed according to a method found in the literature[2], where the authors presented fluorescence spectra as relative, normalized spectra: the curve for protein + SDS was subtracted from the curve for protein + buffer, and the resulting relative spectrum was then normalized at the short-wavelength minimum to –100 units. The obtained fluorescence spectra are presented in Figure 1. This way of presenting the spectra allows for the analysis of the total effect of the signal change compared to the initial value.
....
45.
Truong, Duc Toan; Ho, Kiet; Huy, Pham Dinh Quoc; Chwastyk, Mateusz; Nguyen-Minh, Thai; Nguyen, Minh Tho
Treatment of flexibility of protein backbone in simulations of protein-ligand interactions using steered molecular dynamics Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Treatment of flexibility of protein backbone in simulations of protein-ligand interactions using steered molecular dynamics},
author = {Duc Toan Truong and Kiet Ho and Pham Dinh Quoc Huy and Mateusz Chwastyk and Thai Nguyen-Minh and Minh Tho Nguyen },
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {To ensure that an external force can break the interaction between a protein and a ligand, the steered molecular dynamics simulation requires a harmonic restrained potential applied to the protein backbone. A usual practice is that all or a certain number of protein’s heavy atoms or Cα atoms are fixed, being restrained by a small force. This present study reveals that while fixing both either all heavy atoms and or all Cα atoms is not a good approach, while fixing a too small number of few atoms sometimes cannot prevent the protein from rotating under the influence of the bulk water layer, and the pulled molecule may smack into the wall of the active site. We found that restraining the Cα atoms under certain conditions is more relevant. Thus, we would propose an alternative solution in which only the Cα atoms of the protein at a distance larger than 1.2 nm from the ligand are restrained. A more flexible, but not too flexible, protein will be expected to lead to a more natural release of the ligand....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
To ensure that an external force can break the interaction between a protein and a ligand, the steered molecular dynamics simulation requires a harmonic restrained potential applied to the protein backbone. A usual practice is that all or a certain number of protein’s heavy atoms or Cα atoms are fixed, being restrained by a small force. This present study reveals that while fixing both either all heavy atoms and or all Cα atoms is not a good approach, while fixing a too small number of few atoms sometimes cannot prevent the protein from rotating under the influence of the bulk water layer, and the pulled molecule may smack into the wall of the active site. We found that restraining the Cα atoms under certain conditions is more relevant. Thus, we would propose an alternative solution in which only the Cα atoms of the protein at a distance larger than 1.2 nm from the ligand are restrained. A more flexible, but not too flexible, protein will be expected to lead to a more natural release of the ligand....
46.
Deptuła, Piotr; Suprewicz, Łukasz; Sawieljew, Mariusz; Bucki, Robert
Biophysical aspects of adipose tissues remodeling during obesity development Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISBN: 2084-1892.
@conference{nokey,
title = {Biophysical aspects of adipose tissues remodeling during obesity development},
author = {Piotr Deptuła and Łukasz Suprewicz and Mariusz Sawieljew and Robert Bucki},
isbn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {During the development of chronic obesity, adipose tissue undergoes significant remodeling, which can result in chronic inflammation leading to fibrosis. This may cause local tissue damage and ultimately initiate dysfunction of multiple organs [1-4].
The aim of this study was to determine the effect of extracellular hyaluronan removal using hyaluronidase on the rheological properties of 3T3-L1 cells during their differentiation process into adipocytes, as well as to perform rheological studies on a lipid-rich adipose tissue hydrogel model. A NanoWizard 4 BioScience AFM (Bruker Nano GmbH, Berlin, Germany), operating in Force Spectroscopy mode, was used to measure the stiffness of confluent cell culture. The Young’s modulus (E) was determined by analyzing force–indentation curves and fitting the data to the Hertz contact model. Rheological characteristics of hydrogels with added lipid elements were evaluated using a strain-controlled Anton Paar MCR702e rheometer (Anton Paar GmbH, Graz, Austria) with a parallel plate setup. The tests quantified the storage modulus (G′) and loss modulus (G″) by measuring the stress required to induce deformation. Two types of shear tests were performed: (1) oscillatory shear strain tests at 1 Hz frequency and 1% amplitude under compressive strain levels of ε = 0%, 10%, 20%, 30%, and 40%; and (2) strain amplitude sweep tests ranging from 0.1% to 100% at a constant frequency of 1 Hz.
The obtained results indicate that the removal of extracellular hyaluronan affects the mechanical properties of adipocytes. The results may contribute to a better understanding of the complex mechanics of the extracellular matrix of adipose tissue, which may affect the process of cell differentiation.
.....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
During the development of chronic obesity, adipose tissue undergoes significant remodeling, which can result in chronic inflammation leading to fibrosis. This may cause local tissue damage and ultimately initiate dysfunction of multiple organs [1-4].
The aim of this study was to determine the effect of extracellular hyaluronan removal using hyaluronidase on the rheological properties of 3T3-L1 cells during their differentiation process into adipocytes, as well as to perform rheological studies on a lipid-rich adipose tissue hydrogel model. A NanoWizard 4 BioScience AFM (Bruker Nano GmbH, Berlin, Germany), operating in Force Spectroscopy mode, was used to measure the stiffness of confluent cell culture. The Young’s modulus (E) was determined by analyzing force–indentation curves and fitting the data to the Hertz contact model. Rheological characteristics of hydrogels with added lipid elements were evaluated using a strain-controlled Anton Paar MCR702e rheometer (Anton Paar GmbH, Graz, Austria) with a parallel plate setup. The tests quantified the storage modulus (G′) and loss modulus (G″) by measuring the stress required to induce deformation. Two types of shear tests were performed: (1) oscillatory shear strain tests at 1 Hz frequency and 1% amplitude under compressive strain levels of ε = 0%, 10%, 20%, 30%, and 40%; and (2) strain amplitude sweep tests ranging from 0.1% to 100% at a constant frequency of 1 Hz.
The obtained results indicate that the removal of extracellular hyaluronan affects the mechanical properties of adipocytes. The results may contribute to a better understanding of the complex mechanics of the extracellular matrix of adipose tissue, which may affect the process of cell differentiation.
.....
The aim of this study was to determine the effect of extracellular hyaluronan removal using hyaluronidase on the rheological properties of 3T3-L1 cells during their differentiation process into adipocytes, as well as to perform rheological studies on a lipid-rich adipose tissue hydrogel model. A NanoWizard 4 BioScience AFM (Bruker Nano GmbH, Berlin, Germany), operating in Force Spectroscopy mode, was used to measure the stiffness of confluent cell culture. The Young’s modulus (E) was determined by analyzing force–indentation curves and fitting the data to the Hertz contact model. Rheological characteristics of hydrogels with added lipid elements were evaluated using a strain-controlled Anton Paar MCR702e rheometer (Anton Paar GmbH, Graz, Austria) with a parallel plate setup. The tests quantified the storage modulus (G′) and loss modulus (G″) by measuring the stress required to induce deformation. Two types of shear tests were performed: (1) oscillatory shear strain tests at 1 Hz frequency and 1% amplitude under compressive strain levels of ε = 0%, 10%, 20%, 30%, and 40%; and (2) strain amplitude sweep tests ranging from 0.1% to 100% at a constant frequency of 1 Hz.
The obtained results indicate that the removal of extracellular hyaluronan affects the mechanical properties of adipocytes. The results may contribute to a better understanding of the complex mechanics of the extracellular matrix of adipose tissue, which may affect the process of cell differentiation.
.....
47.
Śmiałek-Bartyzel, Justyna; Frydrych, Jakub; Łukowicz, Krzysztof; Grygier, Beata; Trojan, Ewa; Basta-Kaim, Agnieszka; Lekka, Małgorzata
Effects of LPS and FPR2 agonist (IG4) on the mechanical properties of microglial cells Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Effects of LPS and FPR2 agonist (IG4) on the mechanical properties of microglial cells},
author = {Justyna Śmiałek-Bartyzel and Jakub Frydrych and Krzysztof Łukowicz and Beata Grygier and Ewa Trojan and Agnieszka Basta-Kaim and Małgorzata Lekka},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Alzheimer's disease is a common neurodegenerative disease characterized by chronic inflammation and the accumulation of beta-amyloid (Aβ) in the brain. Microglial cells, resident macrophages in the central nervous system, are thought to play a significant role in the development of this disease. These cells have both neurotoxic and neuroprotective effects. [1]
The presented studies aimed to investigate microglia's biomechanical properties (cell rigidity) in inflammatory conditions. The primary microglial cells obtained from the knock-in murine model of late-onset Alzheimer's disease (APPNLF/NLF) and wild-type mice (WT) isolated from 1- or 2-day-old mice were used in experiments. Isolated cells were cultured in the presence or absence of bacterial endotoxin (lipopolysaccharide, LPS). Moreover, the impact of an agonist of formyl peptide receptor 2 (FPR2) (IG4) in basal and LPS-stimulated conditions was investigated. The biomechanical measurements were performed using atomic force microscopy (AFM), which worked in force spectroscopy mode. Data were collected over the nucleus region, and the Hertz-Sneddon model was used to evaluate the mechanical properties of cells.
Significant changes in the morphology of LPS-treated microglial cells from WT or APPNLF/NLF mice, contrary to non-stimulated cells, were observed. In basal conditions, WT microglia's mechanical properties differed from APPNLF/NLF microglia. LPS significantly increased the elastic modulus for microglial cells in both models. In basal condition IG4 agonist did not affect the biomechanical properties of microglial cells from WT and APPNLF/NLF mice. However, after immunoactivation evoked by LPS stimulation, this agonist has varied effects. In microglia cultures obtained from WT mice, IG4 significantly increases the LPS-evoked increase in Young's modulus. In the case of APPNLF/NLF microglia, IG4 lowered Young's modulus enhancement evoked by LPS.
In summary, our results indicate that inflammation, mimicked by LPS treatment, affects the biomechanical properties of mouse microglial cells. Moreover, the FPR2 agonist compound IG4 enhances the effect of LPS in cells isolated from WT mice, while reducing the LPS effect in cells isolated from APP mice. ...
},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Alzheimer's disease is a common neurodegenerative disease characterized by chronic inflammation and the accumulation of beta-amyloid (Aβ) in the brain. Microglial cells, resident macrophages in the central nervous system, are thought to play a significant role in the development of this disease. These cells have both neurotoxic and neuroprotective effects. [1]
The presented studies aimed to investigate microglia's biomechanical properties (cell rigidity) in inflammatory conditions. The primary microglial cells obtained from the knock-in murine model of late-onset Alzheimer's disease (APPNLF/NLF) and wild-type mice (WT) isolated from 1- or 2-day-old mice were used in experiments. Isolated cells were cultured in the presence or absence of bacterial endotoxin (lipopolysaccharide, LPS). Moreover, the impact of an agonist of formyl peptide receptor 2 (FPR2) (IG4) in basal and LPS-stimulated conditions was investigated. The biomechanical measurements were performed using atomic force microscopy (AFM), which worked in force spectroscopy mode. Data were collected over the nucleus region, and the Hertz-Sneddon model was used to evaluate the mechanical properties of cells.
Significant changes in the morphology of LPS-treated microglial cells from WT or APPNLF/NLF mice, contrary to non-stimulated cells, were observed. In basal conditions, WT microglia's mechanical properties differed from APPNLF/NLF microglia. LPS significantly increased the elastic modulus for microglial cells in both models. In basal condition IG4 agonist did not affect the biomechanical properties of microglial cells from WT and APPNLF/NLF mice. However, after immunoactivation evoked by LPS stimulation, this agonist has varied effects. In microglia cultures obtained from WT mice, IG4 significantly increases the LPS-evoked increase in Young's modulus. In the case of APPNLF/NLF microglia, IG4 lowered Young's modulus enhancement evoked by LPS.
In summary, our results indicate that inflammation, mimicked by LPS treatment, affects the biomechanical properties of mouse microglial cells. Moreover, the FPR2 agonist compound IG4 enhances the effect of LPS in cells isolated from WT mice, while reducing the LPS effect in cells isolated from APP mice. ...
The presented studies aimed to investigate microglia's biomechanical properties (cell rigidity) in inflammatory conditions. The primary microglial cells obtained from the knock-in murine model of late-onset Alzheimer's disease (APPNLF/NLF) and wild-type mice (WT) isolated from 1- or 2-day-old mice were used in experiments. Isolated cells were cultured in the presence or absence of bacterial endotoxin (lipopolysaccharide, LPS). Moreover, the impact of an agonist of formyl peptide receptor 2 (FPR2) (IG4) in basal and LPS-stimulated conditions was investigated. The biomechanical measurements were performed using atomic force microscopy (AFM), which worked in force spectroscopy mode. Data were collected over the nucleus region, and the Hertz-Sneddon model was used to evaluate the mechanical properties of cells.
Significant changes in the morphology of LPS-treated microglial cells from WT or APPNLF/NLF mice, contrary to non-stimulated cells, were observed. In basal conditions, WT microglia's mechanical properties differed from APPNLF/NLF microglia. LPS significantly increased the elastic modulus for microglial cells in both models. In basal condition IG4 agonist did not affect the biomechanical properties of microglial cells from WT and APPNLF/NLF mice. However, after immunoactivation evoked by LPS stimulation, this agonist has varied effects. In microglia cultures obtained from WT mice, IG4 significantly increases the LPS-evoked increase in Young's modulus. In the case of APPNLF/NLF microglia, IG4 lowered Young's modulus enhancement evoked by LPS.
In summary, our results indicate that inflammation, mimicked by LPS treatment, affects the biomechanical properties of mouse microglial cells. Moreover, the FPR2 agonist compound IG4 enhances the effect of LPS in cells isolated from WT mice, while reducing the LPS effect in cells isolated from APP mice. ...
48.
Żochowski, Krzysztof; Szczepanek-Dulska, Monika; Pogoda, Katarzyna; Bucki, Robert
Substrate viscoelasticity and adhesive ligands as regulators of glioma cell migration Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Substrate viscoelasticity and adhesive ligands as regulators of glioma cell migration},
author = {Krzysztof Żochowski and Monika Szczepanek-Dulska and Katarzyna Pogoda and Robert Bucki},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Gliomas are highly invasive brain tumors with a poor prognosis due to their ability to adapt to the unique mechanical and biochemical properties of the brain, which are largely defined by the extracellular matrix (ECM) [1]. While the role of ECM stiffness in tumor progression has been relatively studied [2], the contribution of ECM viscoelasticity to glioma cell behavior is poorly characterized. The presence of specific ECM adhesion ligands plays a key role in modulating cell-substrate interactions [3] and may further influence glioma cell migration which is a fundamental event in cancer progression [4, 5, 6].
This study aims to investigate how the viscoelastic properties of ECM, in combination with specific adhesive ligands (collagen I, fibronectin, laminin), modulate the migration dynamics of glioma cells.
Human glioma cells were cultured on polyacrylamide- based hydrogels with constant storage (G’) and varying loss module (G”), mimicking brain tissue viscoelasticity [7]. Hydrogels and glass surface which serve as a control were functionalized with collagen I, fibronectin or laminin [3]. Cell migration was assessed using time-lapse microscopy and image analysis using ImageJ (Fiji).
We observed that ECM viscoelasticity along with adhesive ligand type modulates glioma cell motility. Understanding the complex interactions between mechanical and biochemical cues in the tumor microenvironment may be used to develop new therapeutic strategies aimed at reducing glioma invasiveness.},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Gliomas are highly invasive brain tumors with a poor prognosis due to their ability to adapt to the unique mechanical and biochemical properties of the brain, which are largely defined by the extracellular matrix (ECM) [1]. While the role of ECM stiffness in tumor progression has been relatively studied [2], the contribution of ECM viscoelasticity to glioma cell behavior is poorly characterized. The presence of specific ECM adhesion ligands plays a key role in modulating cell-substrate interactions [3] and may further influence glioma cell migration which is a fundamental event in cancer progression [4, 5, 6].
This study aims to investigate how the viscoelastic properties of ECM, in combination with specific adhesive ligands (collagen I, fibronectin, laminin), modulate the migration dynamics of glioma cells.
Human glioma cells were cultured on polyacrylamide- based hydrogels with constant storage (G’) and varying loss module (G”), mimicking brain tissue viscoelasticity [7]. Hydrogels and glass surface which serve as a control were functionalized with collagen I, fibronectin or laminin [3]. Cell migration was assessed using time-lapse microscopy and image analysis using ImageJ (Fiji).
We observed that ECM viscoelasticity along with adhesive ligand type modulates glioma cell motility. Understanding the complex interactions between mechanical and biochemical cues in the tumor microenvironment may be used to develop new therapeutic strategies aimed at reducing glioma invasiveness.
This study aims to investigate how the viscoelastic properties of ECM, in combination with specific adhesive ligands (collagen I, fibronectin, laminin), modulate the migration dynamics of glioma cells.
Human glioma cells were cultured on polyacrylamide- based hydrogels with constant storage (G’) and varying loss module (G”), mimicking brain tissue viscoelasticity [7]. Hydrogels and glass surface which serve as a control were functionalized with collagen I, fibronectin or laminin [3]. Cell migration was assessed using time-lapse microscopy and image analysis using ImageJ (Fiji).
We observed that ECM viscoelasticity along with adhesive ligand type modulates glioma cell motility. Understanding the complex interactions between mechanical and biochemical cues in the tumor microenvironment may be used to develop new therapeutic strategies aimed at reducing glioma invasiveness.
49.
Węglińska, Gabriela; Bednarczyk, Piotr; Zając, Mirosław
The effect of pollution on the electrophysiology of epithelium – insights from Caco-2 cell model Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {The effect of pollution on the electrophysiology of epithelium – insights from Caco-2 cell model},
author = {Gabriela Węglińska and Piotr Bednarczyk and Mirosław Zając},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {The problem of plastic pollution and its impact on living organisms has now become a critical environmental concern. The breakdown of plastic debris produces micro- and nanoparticles which are ingested by living organisms and interact with the intestinal barrier. However, our understanding of their effects on human epithelial tissues and transepithelial water and ion transport remains limited. The aim of this study was to investigate the influence of polystyrene nanoplastics: PS-NPs (100 nm diameter) on the human intestinal epithelial cell line Caco-2.
This research focused on the observed increased mucus secretion displayed by Caco-2 cells in response to PS-NPs treatment. Utilizing Ussing chamber studies, we deduced that PS-NPs alter ion transport across cell monolayers. The presence of nanoplastics decreased CFTR channel activity, however, increased the activity of CaCC channels, e.g. TMEM16a. The TMEM16a channel involvement was verified using both ion transporting proteins modulators and the Fura-2 calcium indicator. The study also verified the cytotoxic properties of PS-NPs and its influence on TEER (Transepithelial Electrical Resistance).
This research validates that the elevated TMEM16a activity was responsible for the observed increased mucus secretion, acting as a recently discovered defence mechanism of Caco-2 cells against PS-NPs. ...},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The problem of plastic pollution and its impact on living organisms has now become a critical environmental concern. The breakdown of plastic debris produces micro- and nanoparticles which are ingested by living organisms and interact with the intestinal barrier. However, our understanding of their effects on human epithelial tissues and transepithelial water and ion transport remains limited. The aim of this study was to investigate the influence of polystyrene nanoplastics: PS-NPs (100 nm diameter) on the human intestinal epithelial cell line Caco-2.
This research focused on the observed increased mucus secretion displayed by Caco-2 cells in response to PS-NPs treatment. Utilizing Ussing chamber studies, we deduced that PS-NPs alter ion transport across cell monolayers. The presence of nanoplastics decreased CFTR channel activity, however, increased the activity of CaCC channels, e.g. TMEM16a. The TMEM16a channel involvement was verified using both ion transporting proteins modulators and the Fura-2 calcium indicator. The study also verified the cytotoxic properties of PS-NPs and its influence on TEER (Transepithelial Electrical Resistance).
This research validates that the elevated TMEM16a activity was responsible for the observed increased mucus secretion, acting as a recently discovered defence mechanism of Caco-2 cells against PS-NPs. ...
This research focused on the observed increased mucus secretion displayed by Caco-2 cells in response to PS-NPs treatment. Utilizing Ussing chamber studies, we deduced that PS-NPs alter ion transport across cell monolayers. The presence of nanoplastics decreased CFTR channel activity, however, increased the activity of CaCC channels, e.g. TMEM16a. The TMEM16a channel involvement was verified using both ion transporting proteins modulators and the Fura-2 calcium indicator. The study also verified the cytotoxic properties of PS-NPs and its influence on TEER (Transepithelial Electrical Resistance).
This research validates that the elevated TMEM16a activity was responsible for the observed increased mucus secretion, acting as a recently discovered defence mechanism of Caco-2 cells against PS-NPs. ...
50.
Kawałkiewicz, Weronika; Majewska, Anna; Janus-Kubiak, Marta; Marcinkowska-Gapińska, Anna; Hojan-Jezierska, Dorota; Kubisz, Leszek
IMIX as a parameter used in the evaluation of collagen treatment for lower leg ulcers Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {IMIX as a parameter used in the evaluation of collagen treatment for lower leg ulcers},
author = {Weronika Kawałkiewicz and Anna Majewska and Marta Janus-Kubiak and Anna Marcinkowska-Gapińska and Dorota Hojan-Jezierska and Leszek Kubisz},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Leg ulcers affect over 1% of the adult population. In individuals over the age of 80 it's about 3%. Various treatment methods exist for leg ulcers. One of them is collagen therapy. In this method, patients applied collagen to the skin surrounding the ulcer by massaging it in daily for a period of 12 weeks. 89 patients diagnosed with unilateral lower leg ulcers were included in the study. Patients were assigned to the treatment or control group
The condition of the skin during therapy was assessed using electrical parameters, including the IMIX parameter. This parameter is one of the Ollmar parameters and reflects changes in skin reactance. It is defined as the ratio of the imaginary component of impedance at 20 kHz to the real component of impedance at 500 kHz. Measurements were taken at weeks 0, 4, 8, 12, and again at week 24 (after the collagen treatment) in both the treatment and control groups.
The results demonstrated that electrical parameters, including IMIX, may be useful in evaluating skin condition. This conclusion is supported by the presence of statistically significant differences between the treatment and control groups at three stages of the collagen therapy. Therefore, the IMIX parameter may be considered a valuable tool for monitoring skin condition during collagen treatment in the management of lower leg ulcers. ...},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Leg ulcers affect over 1% of the adult population. In individuals over the age of 80 it's about 3%. Various treatment methods exist for leg ulcers. One of them is collagen therapy. In this method, patients applied collagen to the skin surrounding the ulcer by massaging it in daily for a period of 12 weeks. 89 patients diagnosed with unilateral lower leg ulcers were included in the study. Patients were assigned to the treatment or control group
The condition of the skin during therapy was assessed using electrical parameters, including the IMIX parameter. This parameter is one of the Ollmar parameters and reflects changes in skin reactance. It is defined as the ratio of the imaginary component of impedance at 20 kHz to the real component of impedance at 500 kHz. Measurements were taken at weeks 0, 4, 8, 12, and again at week 24 (after the collagen treatment) in both the treatment and control groups.
The results demonstrated that electrical parameters, including IMIX, may be useful in evaluating skin condition. This conclusion is supported by the presence of statistically significant differences between the treatment and control groups at three stages of the collagen therapy. Therefore, the IMIX parameter may be considered a valuable tool for monitoring skin condition during collagen treatment in the management of lower leg ulcers. ...
The condition of the skin during therapy was assessed using electrical parameters, including the IMIX parameter. This parameter is one of the Ollmar parameters and reflects changes in skin reactance. It is defined as the ratio of the imaginary component of impedance at 20 kHz to the real component of impedance at 500 kHz. Measurements were taken at weeks 0, 4, 8, 12, and again at week 24 (after the collagen treatment) in both the treatment and control groups.
The results demonstrated that electrical parameters, including IMIX, may be useful in evaluating skin condition. This conclusion is supported by the presence of statistically significant differences between the treatment and control groups at three stages of the collagen therapy. Therefore, the IMIX parameter may be considered a valuable tool for monitoring skin condition during collagen treatment in the management of lower leg ulcers. ...
51.
Maniewska, Jadwiga; Gębczak, Katarzyna; Cwynar-Zając, Łucja; Szczęśniak-Sięga, Berenika
New 1,2-benzothiazine derivatives as inhibitors of cyclooxygenase with membrane perturbing potency Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {New 1,2-benzothiazine derivatives as inhibitors of cyclooxygenase with membrane perturbing potency},
author = {Jadwiga Maniewska and Katarzyna Gębczak and Łucja Cwynar-Zając and Berenika Szczęśniak-Sięga},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Cyclooxygenase (COX) is an enzyme located in the lumen of the endoplasmic reticulum, the Golgi apparatus and the nuclear membrane of the cell, embedded with hydrophobic fragments in the lipid bilayer of the membrane. COX catalyzes the process of prostanoid synthesis, i.e. prostaglandins, prostacyclin and thromboxane from arachidonic acid [1]. However, since inflammation has been linked to cancer development, the search for new, safer anti-inflammatory drugs has become even more important [2,3].
In our previous studies, we obtained a series of 1,2-benzothiazine derivatives with anti-inflammatory and analgesic activity confirmed in in vivo tests on mice [4].
In this study, a series of 1,2-benzothiazine derivatives (Tab. 1) were evaluated. In particular we investigated the interactions of the potential drugs with lipid bilayers, an important consideration for membrane permeability and overall pharmacokinetics. We have used differential scanning calorimetry method (DSC) to determine the interactions of studied compounds with phospholipid bilayers as models of biological membranes [5]. All examined compounds decreased the main transition temperature of phospholipid used to obtain the model membranes (DMPC) in a concentration-dependent manner. The addition of 1,2-benzothiazine derivatives to phospholipid also resulted in broadening of the transition peaks. Moreover, all examined compounds decreased the enthalpy of the DMPC main phase transition. It was therefore concluded that all the compounds interacted with phosphatidylcholine model membrane affecting its thermotropic properties. Although the greatest impact on the main transition temperature change was observed for the compounds PR25, PR49 and PR50. In addition, we evaluated the ability of studied compounds to inhibit COX-1 and COX-2 activity and selectivity using cyclooxygenase inhibition assay. ....
Our findings suggest that the 1,2-benzothiazine derivatives could serve as potential lead candidates for the development of safer anti-inflammatory agents},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Cyclooxygenase (COX) is an enzyme located in the lumen of the endoplasmic reticulum, the Golgi apparatus and the nuclear membrane of the cell, embedded with hydrophobic fragments in the lipid bilayer of the membrane. COX catalyzes the process of prostanoid synthesis, i.e. prostaglandins, prostacyclin and thromboxane from arachidonic acid [1]. However, since inflammation has been linked to cancer development, the search for new, safer anti-inflammatory drugs has become even more important [2,3].
In our previous studies, we obtained a series of 1,2-benzothiazine derivatives with anti-inflammatory and analgesic activity confirmed in in vivo tests on mice [4].
In this study, a series of 1,2-benzothiazine derivatives (Tab. 1) were evaluated. In particular we investigated the interactions of the potential drugs with lipid bilayers, an important consideration for membrane permeability and overall pharmacokinetics. We have used differential scanning calorimetry method (DSC) to determine the interactions of studied compounds with phospholipid bilayers as models of biological membranes [5]. All examined compounds decreased the main transition temperature of phospholipid used to obtain the model membranes (DMPC) in a concentration-dependent manner. The addition of 1,2-benzothiazine derivatives to phospholipid also resulted in broadening of the transition peaks. Moreover, all examined compounds decreased the enthalpy of the DMPC main phase transition. It was therefore concluded that all the compounds interacted with phosphatidylcholine model membrane affecting its thermotropic properties. Although the greatest impact on the main transition temperature change was observed for the compounds PR25, PR49 and PR50. In addition, we evaluated the ability of studied compounds to inhibit COX-1 and COX-2 activity and selectivity using cyclooxygenase inhibition assay. ....
Our findings suggest that the 1,2-benzothiazine derivatives could serve as potential lead candidates for the development of safer anti-inflammatory agents
In our previous studies, we obtained a series of 1,2-benzothiazine derivatives with anti-inflammatory and analgesic activity confirmed in in vivo tests on mice [4].
In this study, a series of 1,2-benzothiazine derivatives (Tab. 1) were evaluated. In particular we investigated the interactions of the potential drugs with lipid bilayers, an important consideration for membrane permeability and overall pharmacokinetics. We have used differential scanning calorimetry method (DSC) to determine the interactions of studied compounds with phospholipid bilayers as models of biological membranes [5]. All examined compounds decreased the main transition temperature of phospholipid used to obtain the model membranes (DMPC) in a concentration-dependent manner. The addition of 1,2-benzothiazine derivatives to phospholipid also resulted in broadening of the transition peaks. Moreover, all examined compounds decreased the enthalpy of the DMPC main phase transition. It was therefore concluded that all the compounds interacted with phosphatidylcholine model membrane affecting its thermotropic properties. Although the greatest impact on the main transition temperature change was observed for the compounds PR25, PR49 and PR50. In addition, we evaluated the ability of studied compounds to inhibit COX-1 and COX-2 activity and selectivity using cyclooxygenase inhibition assay. ....
Our findings suggest that the 1,2-benzothiazine derivatives could serve as potential lead candidates for the development of safer anti-inflammatory agents
52.
Bielska, Beata; Kadib, Abdelkrim El; Miłowska, Katarzyna
Toxicity assessment of chitosan-based films modified with quercetin and metals - preliminary wound healing studies Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Toxicity assessment of chitosan-based films modified with quercetin and metals - preliminary wound healing studies},
author = {Beata Bielska and Abdelkrim El Kadib and Katarzyna Miłowska},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Chitosan has found applications in various industries such as medicine, agriculture, textiles, food and environmental protection due to its many beneficial properties. In medicine, chitosan-based materials are used as dressings to speed up the healing process of injuries and burns. In skin and bone tissue engineering, chitosan is used to produce a variety of materials including membranes, hydrogels, sponges and fibres. Scientific literature also indicates the potential of chitosan and chitosan-engineered materials as drug carriers, including anti-cancer drugs, intranasal drugs, gene delivery drugs, prenatal drugs and ocular drug delivery systems [1-3].
Quercetin is a flavonoid with potent antioxidant and anti-inflammatory properties. As an antioxidant, it protects cells from oxidative stress, which promotes tissue regeneration. In addition, quercetin has anti-inflammatory effects by inhibiting the activity of enzymes and reducing the secretion of pro-inflammatory cytokines, which further promotes the healing process, especially during the inflammatory phase [4-5].
Based on their individual properties, we concluded that the combination of quercetin and chitosan films may induce synergistic effects, combining the properties of both substances for more effective wound healing. As a prelude to wound healing, we are evaluating the effects of these films on erythrocytes, peripheral blood mononuclear cells (PBMC) and human dermal fibroblasts (BJ line) in vitro.
The aim of this study is to evaluate the biocompatibility of chitosan films modified with quercetin and metals (Ag, Au, Cu, Bi) with blood cells and skin fibroblasts (BJ line) by assessing haemotoxicity, cytotoxicity and genotoxicity.
Chitosan films showed low toxicity to human erythrocytes, around 5%. Silver-containing nanomaterials showed higher toxicity (above 10%), depending on the silver content of the particle. In cytotoxicity analyses, silver-containing nanocomposites were more toxic than other chitosan films. Other variants showed a favourable toxicity profile, suggesting further research into their potential use in wound healing. Analysis of damage to genetic material showed low levels of damage. The addition of quercetin, a natural antioxidant, may partially mitigate the adverse effects of silver. Therefore, chitosan-quercetin metal films may have reduced cytotoxicity to skin fibroblasts and other human cells, increasing their potential for use in tissue engineering and wound healing. ...},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Chitosan has found applications in various industries such as medicine, agriculture, textiles, food and environmental protection due to its many beneficial properties. In medicine, chitosan-based materials are used as dressings to speed up the healing process of injuries and burns. In skin and bone tissue engineering, chitosan is used to produce a variety of materials including membranes, hydrogels, sponges and fibres. Scientific literature also indicates the potential of chitosan and chitosan-engineered materials as drug carriers, including anti-cancer drugs, intranasal drugs, gene delivery drugs, prenatal drugs and ocular drug delivery systems [1-3].
Quercetin is a flavonoid with potent antioxidant and anti-inflammatory properties. As an antioxidant, it protects cells from oxidative stress, which promotes tissue regeneration. In addition, quercetin has anti-inflammatory effects by inhibiting the activity of enzymes and reducing the secretion of pro-inflammatory cytokines, which further promotes the healing process, especially during the inflammatory phase [4-5].
Based on their individual properties, we concluded that the combination of quercetin and chitosan films may induce synergistic effects, combining the properties of both substances for more effective wound healing. As a prelude to wound healing, we are evaluating the effects of these films on erythrocytes, peripheral blood mononuclear cells (PBMC) and human dermal fibroblasts (BJ line) in vitro.
The aim of this study is to evaluate the biocompatibility of chitosan films modified with quercetin and metals (Ag, Au, Cu, Bi) with blood cells and skin fibroblasts (BJ line) by assessing haemotoxicity, cytotoxicity and genotoxicity.
Chitosan films showed low toxicity to human erythrocytes, around 5%. Silver-containing nanomaterials showed higher toxicity (above 10%), depending on the silver content of the particle. In cytotoxicity analyses, silver-containing nanocomposites were more toxic than other chitosan films. Other variants showed a favourable toxicity profile, suggesting further research into their potential use in wound healing. Analysis of damage to genetic material showed low levels of damage. The addition of quercetin, a natural antioxidant, may partially mitigate the adverse effects of silver. Therefore, chitosan-quercetin metal films may have reduced cytotoxicity to skin fibroblasts and other human cells, increasing their potential for use in tissue engineering and wound healing. ...
Quercetin is a flavonoid with potent antioxidant and anti-inflammatory properties. As an antioxidant, it protects cells from oxidative stress, which promotes tissue regeneration. In addition, quercetin has anti-inflammatory effects by inhibiting the activity of enzymes and reducing the secretion of pro-inflammatory cytokines, which further promotes the healing process, especially during the inflammatory phase [4-5].
Based on their individual properties, we concluded that the combination of quercetin and chitosan films may induce synergistic effects, combining the properties of both substances for more effective wound healing. As a prelude to wound healing, we are evaluating the effects of these films on erythrocytes, peripheral blood mononuclear cells (PBMC) and human dermal fibroblasts (BJ line) in vitro.
The aim of this study is to evaluate the biocompatibility of chitosan films modified with quercetin and metals (Ag, Au, Cu, Bi) with blood cells and skin fibroblasts (BJ line) by assessing haemotoxicity, cytotoxicity and genotoxicity.
Chitosan films showed low toxicity to human erythrocytes, around 5%. Silver-containing nanomaterials showed higher toxicity (above 10%), depending on the silver content of the particle. In cytotoxicity analyses, silver-containing nanocomposites were more toxic than other chitosan films. Other variants showed a favourable toxicity profile, suggesting further research into their potential use in wound healing. Analysis of damage to genetic material showed low levels of damage. The addition of quercetin, a natural antioxidant, may partially mitigate the adverse effects of silver. Therefore, chitosan-quercetin metal films may have reduced cytotoxicity to skin fibroblasts and other human cells, increasing their potential for use in tissue engineering and wound healing. ...
53.
Perz, Martyna; Środa-Pomianek, Kamila; Pałko-Łabuz, Anna; Szymanowska, Daria; Kostrzewa-Susłow, Edyta; Wesołowska, Olga
Physicochemical Descriptors of Halogenated Flavonoids: Insights into Their Antibacterial Potential Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Physicochemical Descriptors of Halogenated Flavonoids: Insights into Their Antibacterial Potential},
author = {Martyna Perz and Kamila Środa-Pomianek and Anna Pałko-Łabuz and Daria Szymanowska and Edyta Kostrzewa-Susłow and Olga Wesołowska},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Flavonoids are natural compounds found in plants, known for their anti-inflammatory, cytotoxic, and bactericidal properties. The analysis of flavonoid descriptors is essential for developing new derivatives, predicting biological properties, and understanding their mechanisms of action. With the rise in antibiotic-resistant bacteria, exploring flavonoid derivatives containing halogen atoms (bromine, chlorine), has become increasingly important. These substituents can significantly enhance the antibacterial properties of flavonoids, making them promising candidates for future therapeutic applications [1,2]. In silico studies, leveraging computational methods, offer a powerful approach to elucidate the structure-activity relationships of flavonoids, predict their interactions with biological targets, and explore their pharmacokinetic properties [3].
This study focused on three halogenated flavonoid compounds: 3'-bromo-5'-chloro-2'-hydroxychalcone, 8-bromo-6-chloroflavanone, and 8-bromo-6-chloroflavone. Laboratory experiments and SwissADME in silico analyses were conducted to examine their physicochemical properties, including melting point, molecular weight, polarity, log P, and others. Although the compounds have similar molar masses, differences in structure, bond flexibility, and insaturation were found to influence their biological activity [4].
The results showed that 8-bromo-6-chloroflavanone effectively inhibited the growth of pathogenic bacteria without significantly impacting probiotic bacteria, while 3'-bromo-5'-chloro-2'-hydroxychalcone, and 8-bromo-6-chloroflavone suppressed both probiotic and pathogenic bacteria. The presence of bromine and chlorine atoms enhanced the bactericidal effects compared to quercetin, a commonly studied natural compound [4].
These findings highlight the potential of halogenated flavonoids as alternatives to current natural products, particularly in regulating intestinal microbiota. Further research will explore their mechanisms of action and include additional in vitro and in vivo studies, focusing on their effects on HCT 116, FHC, and Caco-2 cell lines. ....},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Flavonoids are natural compounds found in plants, known for their anti-inflammatory, cytotoxic, and bactericidal properties. The analysis of flavonoid descriptors is essential for developing new derivatives, predicting biological properties, and understanding their mechanisms of action. With the rise in antibiotic-resistant bacteria, exploring flavonoid derivatives containing halogen atoms (bromine, chlorine), has become increasingly important. These substituents can significantly enhance the antibacterial properties of flavonoids, making them promising candidates for future therapeutic applications [1,2]. In silico studies, leveraging computational methods, offer a powerful approach to elucidate the structure-activity relationships of flavonoids, predict their interactions with biological targets, and explore their pharmacokinetic properties [3].
This study focused on three halogenated flavonoid compounds: 3'-bromo-5'-chloro-2'-hydroxychalcone, 8-bromo-6-chloroflavanone, and 8-bromo-6-chloroflavone. Laboratory experiments and SwissADME in silico analyses were conducted to examine their physicochemical properties, including melting point, molecular weight, polarity, log P, and others. Although the compounds have similar molar masses, differences in structure, bond flexibility, and insaturation were found to influence their biological activity [4].
The results showed that 8-bromo-6-chloroflavanone effectively inhibited the growth of pathogenic bacteria without significantly impacting probiotic bacteria, while 3'-bromo-5'-chloro-2'-hydroxychalcone, and 8-bromo-6-chloroflavone suppressed both probiotic and pathogenic bacteria. The presence of bromine and chlorine atoms enhanced the bactericidal effects compared to quercetin, a commonly studied natural compound [4].
These findings highlight the potential of halogenated flavonoids as alternatives to current natural products, particularly in regulating intestinal microbiota. Further research will explore their mechanisms of action and include additional in vitro and in vivo studies, focusing on their effects on HCT 116, FHC, and Caco-2 cell lines. ....
This study focused on three halogenated flavonoid compounds: 3'-bromo-5'-chloro-2'-hydroxychalcone, 8-bromo-6-chloroflavanone, and 8-bromo-6-chloroflavone. Laboratory experiments and SwissADME in silico analyses were conducted to examine their physicochemical properties, including melting point, molecular weight, polarity, log P, and others. Although the compounds have similar molar masses, differences in structure, bond flexibility, and insaturation were found to influence their biological activity [4].
The results showed that 8-bromo-6-chloroflavanone effectively inhibited the growth of pathogenic bacteria without significantly impacting probiotic bacteria, while 3'-bromo-5'-chloro-2'-hydroxychalcone, and 8-bromo-6-chloroflavone suppressed both probiotic and pathogenic bacteria. The presence of bromine and chlorine atoms enhanced the bactericidal effects compared to quercetin, a commonly studied natural compound [4].
These findings highlight the potential of halogenated flavonoids as alternatives to current natural products, particularly in regulating intestinal microbiota. Further research will explore their mechanisms of action and include additional in vitro and in vivo studies, focusing on their effects on HCT 116, FHC, and Caco-2 cell lines. ....
54.
Wojtyś, Marta I.; Narczyk, Marta; Krystian, Monika; Ašler, Ivana Leščić; Bzowska, Agnieszka
Activity of immucillins on the purine nucleoside phosphorylase (PNP) from H. pylori and on the bacterial growth Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Activity of immucillins on the purine nucleoside phosphorylase (PNP) from H. pylori and on the bacterial growth},
author = {Marta I. Wojtyś and Marta Narczyk and Monika Krystian and Ivana Leščić Ašler and Agnieszka Bzowska},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Helicobacter pylori is a gram-negative, microaerophilic bacterium which colonizes the gastric and duodenal mucosa of half of the world's human population, and its presence may cause serious diseases, such as stomach and duodenal ulcers and stomach cancer. Unfortunately, the available therapies fail in 20% of patients due to increasing resistance to the antibiotics used. Therefore, it is very important to search for new molecular targets to design new drugs enabling eradication of H. pylori [1].
Immucillins are a group of synthetic compounds that are analogues of purine nucleosides. They inhibit PNP-catalyzed reactions by imitating their transition state [2]. Kicska et al. [3] have shown that immucillin H (Imm-H) is an inhibitor of PNP from P. falciparum (causing malaria in humans), which, like H. pylori, does not synthesize purines and purine nucleosides de novo, suggesting that it may also inhibit the H. pylori PNP enzyme and the replication of this bacterium. Therefore we decided to characterize interactions of Imm-H and other immucillins with PNP from H. pylori 26695 strain, and their influence on the replication of H. pylori.
Immucillins, which form a strong but slowly forming complex with PNP [2], were incubated with the enzyme in a reaction mixture lacking substrate, and then the reaction was initiated by adding the missing substrate (m7Guo). We showed that immucillin A (Imm-A) (Ki = 1.3 ± 0.2 nM) is a potent inhibitor of H. pylori 26695 PNP, similar to Imm-H (Ki = 9.8 ± 0.8 nM). In contrast, MT-DADMe-ImmA does not inhibit H. pylori PNP.
We determined minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) values for immucillins against the reference strain H. pylori 26695 using the double serial dilution method in liquid medium [4]. Imm-A inhibits the growth of H. pylori (MIC = 80 μM (21 μg/ml)) in contrast to Imm-H, which does not affect the growth of this pathogen. However, Imm-A has no bactericidal effect on H. pylori, while the MBC value for MT-DADMe-ImmA is 5 μM (1.47 μg/ml), but its target is a different H. pylori enzyme.
Our studies show that among the compounds from the immucillin group, the most promising for use in the eradication of H. pylori in humans is Imm-A, which, as an adenosine analogue, does not interact significantly with the host PNP. ...},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Helicobacter pylori is a gram-negative, microaerophilic bacterium which colonizes the gastric and duodenal mucosa of half of the world's human population, and its presence may cause serious diseases, such as stomach and duodenal ulcers and stomach cancer. Unfortunately, the available therapies fail in 20% of patients due to increasing resistance to the antibiotics used. Therefore, it is very important to search for new molecular targets to design new drugs enabling eradication of H. pylori [1].
Immucillins are a group of synthetic compounds that are analogues of purine nucleosides. They inhibit PNP-catalyzed reactions by imitating their transition state [2]. Kicska et al. [3] have shown that immucillin H (Imm-H) is an inhibitor of PNP from P. falciparum (causing malaria in humans), which, like H. pylori, does not synthesize purines and purine nucleosides de novo, suggesting that it may also inhibit the H. pylori PNP enzyme and the replication of this bacterium. Therefore we decided to characterize interactions of Imm-H and other immucillins with PNP from H. pylori 26695 strain, and their influence on the replication of H. pylori.
Immucillins, which form a strong but slowly forming complex with PNP [2], were incubated with the enzyme in a reaction mixture lacking substrate, and then the reaction was initiated by adding the missing substrate (m7Guo). We showed that immucillin A (Imm-A) (Ki = 1.3 ± 0.2 nM) is a potent inhibitor of H. pylori 26695 PNP, similar to Imm-H (Ki = 9.8 ± 0.8 nM). In contrast, MT-DADMe-ImmA does not inhibit H. pylori PNP.
We determined minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) values for immucillins against the reference strain H. pylori 26695 using the double serial dilution method in liquid medium [4]. Imm-A inhibits the growth of H. pylori (MIC = 80 μM (21 μg/ml)) in contrast to Imm-H, which does not affect the growth of this pathogen. However, Imm-A has no bactericidal effect on H. pylori, while the MBC value for MT-DADMe-ImmA is 5 μM (1.47 μg/ml), but its target is a different H. pylori enzyme.
Our studies show that among the compounds from the immucillin group, the most promising for use in the eradication of H. pylori in humans is Imm-A, which, as an adenosine analogue, does not interact significantly with the host PNP. ...
Immucillins are a group of synthetic compounds that are analogues of purine nucleosides. They inhibit PNP-catalyzed reactions by imitating their transition state [2]. Kicska et al. [3] have shown that immucillin H (Imm-H) is an inhibitor of PNP from P. falciparum (causing malaria in humans), which, like H. pylori, does not synthesize purines and purine nucleosides de novo, suggesting that it may also inhibit the H. pylori PNP enzyme and the replication of this bacterium. Therefore we decided to characterize interactions of Imm-H and other immucillins with PNP from H. pylori 26695 strain, and their influence on the replication of H. pylori.
Immucillins, which form a strong but slowly forming complex with PNP [2], were incubated with the enzyme in a reaction mixture lacking substrate, and then the reaction was initiated by adding the missing substrate (m7Guo). We showed that immucillin A (Imm-A) (Ki = 1.3 ± 0.2 nM) is a potent inhibitor of H. pylori 26695 PNP, similar to Imm-H (Ki = 9.8 ± 0.8 nM). In contrast, MT-DADMe-ImmA does not inhibit H. pylori PNP.
We determined minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) values for immucillins against the reference strain H. pylori 26695 using the double serial dilution method in liquid medium [4]. Imm-A inhibits the growth of H. pylori (MIC = 80 μM (21 μg/ml)) in contrast to Imm-H, which does not affect the growth of this pathogen. However, Imm-A has no bactericidal effect on H. pylori, while the MBC value for MT-DADMe-ImmA is 5 μM (1.47 μg/ml), but its target is a different H. pylori enzyme.
Our studies show that among the compounds from the immucillin group, the most promising for use in the eradication of H. pylori in humans is Imm-A, which, as an adenosine analogue, does not interact significantly with the host PNP. ...
55.
Dabrowska-Hulka, Adrianna; Pytlak, Karolina; Maliszewska-Olejniczak, Kamila; Hoser, Jakub; Zajac, Mirosław; Kulawiak, Bogusz; Bednarczyk, Piotr
The role of the mitochondrial BKCa channel in the physiology and damage of respiratory epithelial cells induced by urban particulate matter Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {The role of the mitochondrial BK_{Ca} channel in the physiology and damage of respiratory epithelial cells induced by urban particulate matter},
author = {Adrianna Dabrowska-Hulka and Karolina Pytlak and Kamila Maliszewska-Olejniczak and Jakub Hoser and Mirosław Zajac and Bogusz Kulawiak and Piotr Bednarczyk},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Recently, it has been shown that the inner mitochondrial membrane's potassium channels (mitoK) are involved in cytoprotection. Therefore, protecting epithelial cells from particulate matter (PM)-induced damage may be related to activating potassium channels in the mitochondria.
To verify the role of mitochondrial large-conductance Ca2+-regulated potassium (mitoBKCa) channel in cytoprotection in response to stress induced by PM, we performed a series of experiments using patch-clamp, transepithelial electrical resistance assessment mitochondrial respiration measurements, fluorescence methods for the ROS level and mitochondrial membrane potential assessment, and cell viability measurements using trypan blue staining. In the human bronchiolar lung epithelial cell damage model (16HBE14o- wt), particulate matter 4 m in diameter was used (PM4.0).
We observed that PM decreased the transepithelial electrical resistance in HBE cells dose-dependently. The effect was partially abolished by quercetin, mitoBKCa channel activator. Penitrem A (BKCa channel inhibitor) reversed the effect of quercetin. The patch-clamp findings confirmed that the effect is associated with channels. Quercetin activated the mitoBKCa channel, abolishing the effect of penitrem A. The results were compatible with mitochondrial membrane and respiration measurements. Quercetin decreased the mitochondrial membrane potential and increased mitochondrial respiration. The effect was abolished by penitrem A only in whole-cell respiration measurements. PM-induced ROS levels are reduced at the cellular and mitochondrial levels. It correlates with cell viability results for quercetin, which increases HBE cell viability after PM administration. The toxic effect was also shown at the mitochondrial level. The PM incubation with the cells substantially reduced the mitochondrial function, which was measured as respiration control with fully uncoupled mitochondria compared to the inhibited electron transport chain.
To support our data, we used an analog of quercetin-isorhamnetin, a substance that has one hydroxyl group changed to a methoxy group. After its application, Isorhamnetin has no effect on the mitoBKCa channel activity, respiratory rate, and mitochondrial membrane potential. Additionally, we used CRISPR/Cas9 technology in 16HBE14o- cells to generate cell lines lacking the alpha subunit of the BKCa channel encoded by the KCNMA1 gene. Mitochondrial patch-clamp experiments showed the absence of an active mitoBKCa channel in knockout cells (HBE BK).
A better understanding of the relationship between mitochondrial metabolism and cell pathophysiology could aid in the search for effective cytoprotection strategies. Perhaps, by using naturally derived mitochondrial BKCa channel activators, we will learn to support and induce these mechanisms to counteract the consequences of PM-induced damage. ...},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Recently, it has been shown that the inner mitochondrial membrane's potassium channels (mitoK) are involved in cytoprotection. Therefore, protecting epithelial cells from particulate matter (PM)-induced damage may be related to activating potassium channels in the mitochondria.
To verify the role of mitochondrial large-conductance Ca2+-regulated potassium (mitoBKCa) channel in cytoprotection in response to stress induced by PM, we performed a series of experiments using patch-clamp, transepithelial electrical resistance assessment mitochondrial respiration measurements, fluorescence methods for the ROS level and mitochondrial membrane potential assessment, and cell viability measurements using trypan blue staining. In the human bronchiolar lung epithelial cell damage model (16HBE14o- wt), particulate matter 4 m in diameter was used (PM4.0).
We observed that PM decreased the transepithelial electrical resistance in HBE cells dose-dependently. The effect was partially abolished by quercetin, mitoBKCa channel activator. Penitrem A (BKCa channel inhibitor) reversed the effect of quercetin. The patch-clamp findings confirmed that the effect is associated with channels. Quercetin activated the mitoBKCa channel, abolishing the effect of penitrem A. The results were compatible with mitochondrial membrane and respiration measurements. Quercetin decreased the mitochondrial membrane potential and increased mitochondrial respiration. The effect was abolished by penitrem A only in whole-cell respiration measurements. PM-induced ROS levels are reduced at the cellular and mitochondrial levels. It correlates with cell viability results for quercetin, which increases HBE cell viability after PM administration. The toxic effect was also shown at the mitochondrial level. The PM incubation with the cells substantially reduced the mitochondrial function, which was measured as respiration control with fully uncoupled mitochondria compared to the inhibited electron transport chain.
To support our data, we used an analog of quercetin-isorhamnetin, a substance that has one hydroxyl group changed to a methoxy group. After its application, Isorhamnetin has no effect on the mitoBKCa channel activity, respiratory rate, and mitochondrial membrane potential. Additionally, we used CRISPR/Cas9 technology in 16HBE14o- cells to generate cell lines lacking the alpha subunit of the BKCa channel encoded by the KCNMA1 gene. Mitochondrial patch-clamp experiments showed the absence of an active mitoBKCa channel in knockout cells (HBE BK).
A better understanding of the relationship between mitochondrial metabolism and cell pathophysiology could aid in the search for effective cytoprotection strategies. Perhaps, by using naturally derived mitochondrial BKCa channel activators, we will learn to support and induce these mechanisms to counteract the consequences of PM-induced damage. ...
To verify the role of mitochondrial large-conductance Ca2+-regulated potassium (mitoBKCa) channel in cytoprotection in response to stress induced by PM, we performed a series of experiments using patch-clamp, transepithelial electrical resistance assessment mitochondrial respiration measurements, fluorescence methods for the ROS level and mitochondrial membrane potential assessment, and cell viability measurements using trypan blue staining. In the human bronchiolar lung epithelial cell damage model (16HBE14o- wt), particulate matter 4 m in diameter was used (PM4.0).
We observed that PM decreased the transepithelial electrical resistance in HBE cells dose-dependently. The effect was partially abolished by quercetin, mitoBKCa channel activator. Penitrem A (BKCa channel inhibitor) reversed the effect of quercetin. The patch-clamp findings confirmed that the effect is associated with channels. Quercetin activated the mitoBKCa channel, abolishing the effect of penitrem A. The results were compatible with mitochondrial membrane and respiration measurements. Quercetin decreased the mitochondrial membrane potential and increased mitochondrial respiration. The effect was abolished by penitrem A only in whole-cell respiration measurements. PM-induced ROS levels are reduced at the cellular and mitochondrial levels. It correlates with cell viability results for quercetin, which increases HBE cell viability after PM administration. The toxic effect was also shown at the mitochondrial level. The PM incubation with the cells substantially reduced the mitochondrial function, which was measured as respiration control with fully uncoupled mitochondria compared to the inhibited electron transport chain.
To support our data, we used an analog of quercetin-isorhamnetin, a substance that has one hydroxyl group changed to a methoxy group. After its application, Isorhamnetin has no effect on the mitoBKCa channel activity, respiratory rate, and mitochondrial membrane potential. Additionally, we used CRISPR/Cas9 technology in 16HBE14o- cells to generate cell lines lacking the alpha subunit of the BKCa channel encoded by the KCNMA1 gene. Mitochondrial patch-clamp experiments showed the absence of an active mitoBKCa channel in knockout cells (HBE BK).
A better understanding of the relationship between mitochondrial metabolism and cell pathophysiology could aid in the search for effective cytoprotection strategies. Perhaps, by using naturally derived mitochondrial BKCa channel activators, we will learn to support and induce these mechanisms to counteract the consequences of PM-induced damage. ...
56.
Fryc, Michał; Chuchała, Patrycja; Lenartowicz-Gasik, Aleksandra; Araszkiewicz, Martyna; Jakielaszek, Mateusz; Kamińska, Patrycja; Kaźmierczak, Urszula; Korgul, Agnieszka; Rzadkiewicz, Jacek; Soroka, Wojciech; Kulawiak, Bogusz; Bednarczyk, Piotr; Maliszewska-Olejniczak, Kamila
Radiogenic effects on ion channel function: investigating the role of BKCa potassium channel in DNA damage response Conference
vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Radiogenic effects on ion channel function: investigating the role of BK_{Ca} potassium channel in DNA damage response},
author = {Michał Fryc and Patrycja Chuchała and Aleksandra Lenartowicz-Gasik and Martyna Araszkiewicz and Mateusz Jakielaszek and Patrycja Kamińska and Urszula Kaźmierczak and Agnieszka Korgul and Jacek Rzadkiewicz and Wojciech Soroka and Bogusz Kulawiak and Piotr Bednarczyk and Kamila Maliszewska-Olejniczak},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
publisher = {Polish Biophysical Society and Adam Mickiewicz University},
address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},
abstract = {Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor arising from astrocytes and is classified as WHO grade 4 astrocytoma. Standard treatment includes surgical resection, chemotherapy with temozolomide, and radiation therapy, but the low survival rate of patients highlights the urgency for innovative and more effective therapeutic tools [1]. The response of this type of tumor to chemoradiotherapy is poor, possibly due to a higher repair activity of the genetic material, among other causes. DNA double-strand breaks (DSBs) are an essential type of lesion to the genetic material, which have the potential to trigger processes of cell death or cause gene aberrations that promote tumorigenesis. Radiotherapy eliminates tumor cells by causing DSBs. Therefore, targeting the cellular DNA damage response is a promising strategy to enhance tumor radiosensitivity.
Ionizing radiation (IR) has been shown to stimulate ion transport, which is crucial for the DNA damage response (DDR) [2]. The DNA damage response is a highly coordinated cellular defense mechanism that sustains genomic integrity by detecting and repairing DNA lesions. The pivotal role of DDR in cellular function and survival is emphasized by the association of DDR defects with many human disorders, including cancer, aging, and neurodegenerative diseases. Although the DDR mechanisms have been extensively studied, most research has focused on cytosolic or nuclear proteins rather than biological membrane-present ion channels. Recently, potassium channels have been described as 'oncochannels' involved in tumor progression and treatment resistance in many cancers, highly expressed in bone, breast, ovary, and prostate cancer and glioma [3]. Due to the high drug sensitivity of these channels, targeting them may represent a new approach to treating glioma. According to the latest reports, oncochannels contribute to glioblastoma stem cell properties, program and execute cell migration and invasion, regulate the cell cycle, and confer therapy resistance. Cell migration and invasion in glioblastoma are critically dependent on changes in the level of Ca2+. Moreover, overexpression of large-conductance Ca2+-regulated potassium channel (BKCa) in glioblastoma can promote tumor progression and therapy resistance, which also presents an opportunity for developing novel therapeutic strategies. BKCa channels play a significant role in regulating mitochondrial function and redox homeostasis. These channels are modulated by ROS and other redox-active molecules, which influence their function and, consequently, the redox state of the cell [4]. Modulating BKCa potassium channels could alter cancer cells' response to radiotherapy and potentially overcome treatment resistance. Therefore, the primary goal is to investigate the mechanism of the BKCa channel in DNA damage response in modulation, enhancing the radiosensitivity of cancer cells and overcoming treatment resistance using ionizing radiation and pharmacological approaches. ...},
type = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor arising from astrocytes and is classified as WHO grade 4 astrocytoma. Standard treatment includes surgical resection, chemotherapy with temozolomide, and radiation therapy, but the low survival rate of patients highlights the urgency for innovative and more effective therapeutic tools [1]. The response of this type of tumor to chemoradiotherapy is poor, possibly due to a higher repair activity of the genetic material, among other causes. DNA double-strand breaks (DSBs) are an essential type of lesion to the genetic material, which have the potential to trigger processes of cell death or cause gene aberrations that promote tumorigenesis. Radiotherapy eliminates tumor cells by causing DSBs. Therefore, targeting the cellular DNA damage response is a promising strategy to enhance tumor radiosensitivity.
Ionizing radiation (IR) has been shown to stimulate ion transport, which is crucial for the DNA damage response (DDR) [2]. The DNA damage response is a highly coordinated cellular defense mechanism that sustains genomic integrity by detecting and repairing DNA lesions. The pivotal role of DDR in cellular function and survival is emphasized by the association of DDR defects with many human disorders, including cancer, aging, and neurodegenerative diseases. Although the DDR mechanisms have been extensively studied, most research has focused on cytosolic or nuclear proteins rather than biological membrane-present ion channels. Recently, potassium channels have been described as 'oncochannels' involved in tumor progression and treatment resistance in many cancers, highly expressed in bone, breast, ovary, and prostate cancer and glioma [3]. Due to the high drug sensitivity of these channels, targeting them may represent a new approach to treating glioma. According to the latest reports, oncochannels contribute to glioblastoma stem cell properties, program and execute cell migration and invasion, regulate the cell cycle, and confer therapy resistance. Cell migration and invasion in glioblastoma are critically dependent on changes in the level of Ca2+. Moreover, overexpression of large-conductance Ca2+-regulated potassium channel (BKCa) in glioblastoma can promote tumor progression and therapy resistance, which also presents an opportunity for developing novel therapeutic strategies. BKCa channels play a significant role in regulating mitochondrial function and redox homeostasis. These channels are modulated by ROS and other redox-active molecules, which influence their function and, consequently, the redox state of the cell [4]. Modulating BKCa potassium channels could alter cancer cells' response to radiotherapy and potentially overcome treatment resistance. Therefore, the primary goal is to investigate the mechanism of the BKCa channel in DNA damage response in modulation, enhancing the radiosensitivity of cancer cells and overcoming treatment resistance using ionizing radiation and pharmacological approaches. ...
Ionizing radiation (IR) has been shown to stimulate ion transport, which is crucial for the DNA damage response (DDR) [2]. The DNA damage response is a highly coordinated cellular defense mechanism that sustains genomic integrity by detecting and repairing DNA lesions. The pivotal role of DDR in cellular function and survival is emphasized by the association of DDR defects with many human disorders, including cancer, aging, and neurodegenerative diseases. Although the DDR mechanisms have been extensively studied, most research has focused on cytosolic or nuclear proteins rather than biological membrane-present ion channels. Recently, potassium channels have been described as 'oncochannels' involved in tumor progression and treatment resistance in many cancers, highly expressed in bone, breast, ovary, and prostate cancer and glioma [3]. Due to the high drug sensitivity of these channels, targeting them may represent a new approach to treating glioma. According to the latest reports, oncochannels contribute to glioblastoma stem cell properties, program and execute cell migration and invasion, regulate the cell cycle, and confer therapy resistance. Cell migration and invasion in glioblastoma are critically dependent on changes in the level of Ca2+. Moreover, overexpression of large-conductance Ca2+-regulated potassium channel (BKCa) in glioblastoma can promote tumor progression and therapy resistance, which also presents an opportunity for developing novel therapeutic strategies. BKCa channels play a significant role in regulating mitochondrial function and redox homeostasis. These channels are modulated by ROS and other redox-active molecules, which influence their function and, consequently, the redox state of the cell [4]. Modulating BKCa potassium channels could alter cancer cells' response to radiotherapy and potentially overcome treatment resistance. Therefore, the primary goal is to investigate the mechanism of the BKCa channel in DNA damage response in modulation, enhancing the radiosensitivity of cancer cells and overcoming treatment resistance using ionizing radiation and pharmacological approaches. ...
57.
Hoser, Jakub; Zajac, Mirosław; Sekrecka-Belniak, Anna; Jedrzejczyk, Marta; Huczynski, Adam; Bednarczyk, Piotr
The role of ion transport induced by modified ionophores and compounds of natural origins Conference
vol. 44 (suppl.A), 2025, ISSN: 2084-1892.
@conference{nokey,
title = {The role of ion transport induced by modified ionophores and compounds of natural origins},
author = {Jakub Hoser and Mirosław Zajac and Anna Sekrecka-Belniak and Marta Jedrzejczyk and Adam Huczynski and Piotr Bednarczyk},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
abstract = {Cystic fibrosis is the most common genetic disease among rare diseases. It is caused by mutations in the cftr (cystic fibrosis transmembrane conductance regulator) gene, which encodes the CFTR anion channel. The CFTR channel defect results in abnormal transport of ions and water across the epithelium, leading to thick and sticky lingering mucus in the affected organs [1]. The activity of the CFTR channel is dependent on ATP molecules. Therefore, increasing cellular ATP levels can promote chloride secretion and contribute to better epithelial hydration.
Increasing cellular ATP levels can be induced using mitochondria-directed ionophores capable of transporting ions across biological membranes. Their activity can lead to depolarization of the inner mitochondrial membrane and increase of cellular respiration. In addition, ionophores can affect the electrophysiology of epithelial tissues by participation in various signaling pathways. The same effect can be achieved by compounds of natural origin available in a varied diet. Examples of such compounds are flavonoids, which are capable to activate ion channels and modulating metabolic pathways [2].
The ability of the ionophores used in the study to transport ions across biological membranes and the effects on the electrophysiology of cellular monolayers were studied in Ussing chamber and by Black Lipid Membrane technique. The effects of the tested compounds on changes in the cellular respiration level were studied in Oroboros system. Transepithelial chloride transport was determined in an Ussing chamber. ATP levels were determined by the commercially available bioluminescent assay. In addition, migration assays, viability assays, ROS level and transepithelial electrical resistance of the monolayers were performed. The assays were conducted on respiratory cell lines such as the cancer cell line A549 and the bronchial epithelial cell line 16HBE14o-.
The results of the experiments showed that the targeted compounds exhibited the ability to transport ions across biological membranes, and in a concentration-dependent manner to increase cellular respiration. Ussing chamber experiments showed that the tested mitochondria-directed ionophores did not affect the chloride current flowing through cell monolayers. On the other hand, the experimentally selected flavonoid- luteolin appeared to increase intracellular ATP concentration, transepithelial electrical resistance, affect metabolism, proliferation and modulate chloride secretion.
These findings suggest that luteolin may strengthen the barrier function of human bronchial epithelial (HBE) cells and holds potential to support epithelial hydration mechanisms—offering a promising perspective for therapeutic strategies in cystic fibrosis. ...},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Cystic fibrosis is the most common genetic disease among rare diseases. It is caused by mutations in the cftr (cystic fibrosis transmembrane conductance regulator) gene, which encodes the CFTR anion channel. The CFTR channel defect results in abnormal transport of ions and water across the epithelium, leading to thick and sticky lingering mucus in the affected organs [1]. The activity of the CFTR channel is dependent on ATP molecules. Therefore, increasing cellular ATP levels can promote chloride secretion and contribute to better epithelial hydration.
Increasing cellular ATP levels can be induced using mitochondria-directed ionophores capable of transporting ions across biological membranes. Their activity can lead to depolarization of the inner mitochondrial membrane and increase of cellular respiration. In addition, ionophores can affect the electrophysiology of epithelial tissues by participation in various signaling pathways. The same effect can be achieved by compounds of natural origin available in a varied diet. Examples of such compounds are flavonoids, which are capable to activate ion channels and modulating metabolic pathways [2].
The ability of the ionophores used in the study to transport ions across biological membranes and the effects on the electrophysiology of cellular monolayers were studied in Ussing chamber and by Black Lipid Membrane technique. The effects of the tested compounds on changes in the cellular respiration level were studied in Oroboros system. Transepithelial chloride transport was determined in an Ussing chamber. ATP levels were determined by the commercially available bioluminescent assay. In addition, migration assays, viability assays, ROS level and transepithelial electrical resistance of the monolayers were performed. The assays were conducted on respiratory cell lines such as the cancer cell line A549 and the bronchial epithelial cell line 16HBE14o-.
The results of the experiments showed that the targeted compounds exhibited the ability to transport ions across biological membranes, and in a concentration-dependent manner to increase cellular respiration. Ussing chamber experiments showed that the tested mitochondria-directed ionophores did not affect the chloride current flowing through cell monolayers. On the other hand, the experimentally selected flavonoid- luteolin appeared to increase intracellular ATP concentration, transepithelial electrical resistance, affect metabolism, proliferation and modulate chloride secretion.
These findings suggest that luteolin may strengthen the barrier function of human bronchial epithelial (HBE) cells and holds potential to support epithelial hydration mechanisms—offering a promising perspective for therapeutic strategies in cystic fibrosis. ...
Increasing cellular ATP levels can be induced using mitochondria-directed ionophores capable of transporting ions across biological membranes. Their activity can lead to depolarization of the inner mitochondrial membrane and increase of cellular respiration. In addition, ionophores can affect the electrophysiology of epithelial tissues by participation in various signaling pathways. The same effect can be achieved by compounds of natural origin available in a varied diet. Examples of such compounds are flavonoids, which are capable to activate ion channels and modulating metabolic pathways [2].
The ability of the ionophores used in the study to transport ions across biological membranes and the effects on the electrophysiology of cellular monolayers were studied in Ussing chamber and by Black Lipid Membrane technique. The effects of the tested compounds on changes in the cellular respiration level were studied in Oroboros system. Transepithelial chloride transport was determined in an Ussing chamber. ATP levels were determined by the commercially available bioluminescent assay. In addition, migration assays, viability assays, ROS level and transepithelial electrical resistance of the monolayers were performed. The assays were conducted on respiratory cell lines such as the cancer cell line A549 and the bronchial epithelial cell line 16HBE14o-.
The results of the experiments showed that the targeted compounds exhibited the ability to transport ions across biological membranes, and in a concentration-dependent manner to increase cellular respiration. Ussing chamber experiments showed that the tested mitochondria-directed ionophores did not affect the chloride current flowing through cell monolayers. On the other hand, the experimentally selected flavonoid- luteolin appeared to increase intracellular ATP concentration, transepithelial electrical resistance, affect metabolism, proliferation and modulate chloride secretion.
These findings suggest that luteolin may strengthen the barrier function of human bronchial epithelial (HBE) cells and holds potential to support epithelial hydration mechanisms—offering a promising perspective for therapeutic strategies in cystic fibrosis. ...
58.
Jaworowska, Sandra; Maliszewska-Olejniczak, Kamila; Łukasiak, Agnieszka; Hoser, Jakub; Zając, Mirosław; Bednarczyk, Piotr
The role of the potassium and chloride transport in the development of inflammation induced by particulate matter Conference
vol. 44 (suppl.A), 2025, ISSN: 2084-1892.
@conference{nokey,
title = {The role of the potassium and chloride transport in the development of inflammation induced by particulate matter},
author = {Sandra Jaworowska and Kamila Maliszewska-Olejniczak and Agnieszka Łukasiak and Jakub Hoser and Mirosław Zając and Piotr Bednarczyk},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
abstract = {Particulate matter (PM) poses an increasing threat to human health. Their effects on the human body include the development of inflammation [1]. PM has been shown to exhibit immunomodulatory properties in bronchial epithelial cells by inducing the production of cytokines such as tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) [2].
To investigate the role of ion channels in the development of inflammation, bronchial epithelial cell lines were used: wild-type (HBE WT), with a deletion in the gene encoding the α subunit of the large-conductance potassium channel (HBE ΔαBKCa), and with a mutation of the gene encoding the CFTR channel (CFBE). Each cell line was exposed to various concentrations of PM and assessed for changes in reactive oxygen species production, proinflammatory cytokine secretion (IL-6, TNF-α), mitochondrial respiration (via oxygen consumption rate), intracellular calcium levels, and transepithelial electrical resistance (TEER).
PM exposure significantly increased ROS synthesis and amplified IL-6 and TNF-α release, particularly in HBE ΔαBKCa and CFBE cells. TNF-α induced the highest inflammatory response in HBE ΔαBKCa and CFBE cells compared to HBE WT cells, as measured by IL-6 quantification, suggesting a role for ion channels in the inflammatory response. Mitochondrial function was also adversely affected, as evidenced by reduced maximal respiratory capacity in both HBE ΔαBKCa and CFBE cells relative to HBE WT. Additionally, depending on its concentration, PM increased intracellular calcium ion levels in all cell lines. Finally, PM exposure led to a pronounced reduction in TEER, with CFBE monolayers displaying the most significant susceptibility to barrier disruption.
These studies highlight the vulnerability of potassium and chloride transport disorders in airway epithelial cells to PM-induced injury, which encompasses oxidative and inflammatory stress, mitochondrial dysfunction, and compromised epithelial barrier integrity. Targeting BKCa channel modulation and mitigating oxidative/inflammatory pathways could represent promising therapeutic strategies to protect airway health against environmental pollutants. ...},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Particulate matter (PM) poses an increasing threat to human health. Their effects on the human body include the development of inflammation [1]. PM has been shown to exhibit immunomodulatory properties in bronchial epithelial cells by inducing the production of cytokines such as tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) [2].
To investigate the role of ion channels in the development of inflammation, bronchial epithelial cell lines were used: wild-type (HBE WT), with a deletion in the gene encoding the α subunit of the large-conductance potassium channel (HBE ΔαBKCa), and with a mutation of the gene encoding the CFTR channel (CFBE). Each cell line was exposed to various concentrations of PM and assessed for changes in reactive oxygen species production, proinflammatory cytokine secretion (IL-6, TNF-α), mitochondrial respiration (via oxygen consumption rate), intracellular calcium levels, and transepithelial electrical resistance (TEER).
PM exposure significantly increased ROS synthesis and amplified IL-6 and TNF-α release, particularly in HBE ΔαBKCa and CFBE cells. TNF-α induced the highest inflammatory response in HBE ΔαBKCa and CFBE cells compared to HBE WT cells, as measured by IL-6 quantification, suggesting a role for ion channels in the inflammatory response. Mitochondrial function was also adversely affected, as evidenced by reduced maximal respiratory capacity in both HBE ΔαBKCa and CFBE cells relative to HBE WT. Additionally, depending on its concentration, PM increased intracellular calcium ion levels in all cell lines. Finally, PM exposure led to a pronounced reduction in TEER, with CFBE monolayers displaying the most significant susceptibility to barrier disruption.
These studies highlight the vulnerability of potassium and chloride transport disorders in airway epithelial cells to PM-induced injury, which encompasses oxidative and inflammatory stress, mitochondrial dysfunction, and compromised epithelial barrier integrity. Targeting BKCa channel modulation and mitigating oxidative/inflammatory pathways could represent promising therapeutic strategies to protect airway health against environmental pollutants. ...
To investigate the role of ion channels in the development of inflammation, bronchial epithelial cell lines were used: wild-type (HBE WT), with a deletion in the gene encoding the α subunit of the large-conductance potassium channel (HBE ΔαBKCa), and with a mutation of the gene encoding the CFTR channel (CFBE). Each cell line was exposed to various concentrations of PM and assessed for changes in reactive oxygen species production, proinflammatory cytokine secretion (IL-6, TNF-α), mitochondrial respiration (via oxygen consumption rate), intracellular calcium levels, and transepithelial electrical resistance (TEER).
PM exposure significantly increased ROS synthesis and amplified IL-6 and TNF-α release, particularly in HBE ΔαBKCa and CFBE cells. TNF-α induced the highest inflammatory response in HBE ΔαBKCa and CFBE cells compared to HBE WT cells, as measured by IL-6 quantification, suggesting a role for ion channels in the inflammatory response. Mitochondrial function was also adversely affected, as evidenced by reduced maximal respiratory capacity in both HBE ΔαBKCa and CFBE cells relative to HBE WT. Additionally, depending on its concentration, PM increased intracellular calcium ion levels in all cell lines. Finally, PM exposure led to a pronounced reduction in TEER, with CFBE monolayers displaying the most significant susceptibility to barrier disruption.
These studies highlight the vulnerability of potassium and chloride transport disorders in airway epithelial cells to PM-induced injury, which encompasses oxidative and inflammatory stress, mitochondrial dysfunction, and compromised epithelial barrier integrity. Targeting BKCa channel modulation and mitigating oxidative/inflammatory pathways could represent promising therapeutic strategies to protect airway health against environmental pollutants. ...
59.
Kustra, Agata; Pytlak, Karolina; Kulawiak, Bogusz; Bednarczyk, Piotr; Maliszewska-Olejniczak, Kamila
Polystyrene nanoparticles interfere with DNA repair mechanisms in human intestinal Caco-2 cell line model Conference
vol. 44 (suppl.A), 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Polystyrene nanoparticles interfere with DNA repair mechanisms in human intestinal Caco-2 cell line model},
author = {Agata Kustra and Karolina Pytlak and Bogusz Kulawiak and Piotr Bednarczyk and Kamila Maliszewska-Olejniczak},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
abstract = {Nanoplastic (NP) occurs ubiquitously in aquatic and terrestrial environments, and its harmful biological effects have been observed in a variety of organisms, i.e. bacteria, plants, and animals [1]. Studies on human cells provide fundamental information on key mechanisms of toxicity that will provide answers to the question of whether and how NP poses a health risk. Mechanisms of toxicity mainly include membrane disruption, and production of reactive oxygen species, and may induce DNA damage including oxidative DNA damage (single-strand breaks, SSBs) and DNA double-strand breaks (DSBs) [2]. The emerging concern over environmental nanoparticles, particularly polystyrene (PS) nanoparticles, involves that there is some evidence suggesting that PS particles may be genotoxic in mammalian cells, however, the molecular basis is unclear [3].
This study investigates the interactions between NPs and an immortalized cell line of human colorectal adenocarcinoma cells (Caco-2) by exposing them to various NPs concentrations 50, 100, 400, 800, and 1200 μg/mL). The Caco-2 human epithelial cell line is a prevalent model for studying the intestinal epithelial barrier [4]. Derived from colon cancer, a noteworthy feature of this cell line is its spontaneous differentiation into a monolayer that closely resembles absorptive enterocytes functionally and morphologically, reflecting those found in the intestine.
We assessed potential cytotoxicity using the clonogenic assay and examined NP genotoxicity using the alkaline comet assay and flow cytometry assays (PARP1-dependent apoptosis and cell cycle changes). Our findings indicate a moderate level of NP cytotoxicity observed in the clonogenic assay. Moreover, our preliminary results showed no changes in cell cycle distribution and a minimal increase in the level of apoptotic cells. In addition, no single or double DNA strand breaks were observed. Since we did not observe direct effects, we expect indirect effects mediated by other molecules (e.g., induction of reactive oxygen species (ROS), inhibition of DNA repair mechanisms). To test the likely production of reactive oxygen species by Caco-2 cells in the presence of PNP, DCFDA fluorescent probe staining was performed to determine the level of ROS. After exposure to polystyrene nanoparticles, induction of oxidative stress was observed. We also performed RNA isolation and cDNA synthesis for qPCR assay, which allowed us to check the expression of characteristic genes involved in DNA repair pathways. In particular, critical genes involved in the base excision repair (BER) and DSB repair pathways were downregulated, suggesting a potential impairment of the cell's ability to repair oxidative DNA damage.
This study highlights the sublethal effects of nanoplastics on intestinal barrier cells. It underscores the possible risks of chronic exposure to these environmental contaminants, which can lead to genome instability and other long-term health consequences.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Nanoplastic (NP) occurs ubiquitously in aquatic and terrestrial environments, and its harmful biological effects have been observed in a variety of organisms, i.e. bacteria, plants, and animals [1]. Studies on human cells provide fundamental information on key mechanisms of toxicity that will provide answers to the question of whether and how NP poses a health risk. Mechanisms of toxicity mainly include membrane disruption, and production of reactive oxygen species, and may induce DNA damage including oxidative DNA damage (single-strand breaks, SSBs) and DNA double-strand breaks (DSBs) [2]. The emerging concern over environmental nanoparticles, particularly polystyrene (PS) nanoparticles, involves that there is some evidence suggesting that PS particles may be genotoxic in mammalian cells, however, the molecular basis is unclear [3].
This study investigates the interactions between NPs and an immortalized cell line of human colorectal adenocarcinoma cells (Caco-2) by exposing them to various NPs concentrations 50, 100, 400, 800, and 1200 μg/mL). The Caco-2 human epithelial cell line is a prevalent model for studying the intestinal epithelial barrier [4]. Derived from colon cancer, a noteworthy feature of this cell line is its spontaneous differentiation into a monolayer that closely resembles absorptive enterocytes functionally and morphologically, reflecting those found in the intestine.
We assessed potential cytotoxicity using the clonogenic assay and examined NP genotoxicity using the alkaline comet assay and flow cytometry assays (PARP1-dependent apoptosis and cell cycle changes). Our findings indicate a moderate level of NP cytotoxicity observed in the clonogenic assay. Moreover, our preliminary results showed no changes in cell cycle distribution and a minimal increase in the level of apoptotic cells. In addition, no single or double DNA strand breaks were observed. Since we did not observe direct effects, we expect indirect effects mediated by other molecules (e.g., induction of reactive oxygen species (ROS), inhibition of DNA repair mechanisms). To test the likely production of reactive oxygen species by Caco-2 cells in the presence of PNP, DCFDA fluorescent probe staining was performed to determine the level of ROS. After exposure to polystyrene nanoparticles, induction of oxidative stress was observed. We also performed RNA isolation and cDNA synthesis for qPCR assay, which allowed us to check the expression of characteristic genes involved in DNA repair pathways. In particular, critical genes involved in the base excision repair (BER) and DSB repair pathways were downregulated, suggesting a potential impairment of the cell's ability to repair oxidative DNA damage.
This study highlights the sublethal effects of nanoplastics on intestinal barrier cells. It underscores the possible risks of chronic exposure to these environmental contaminants, which can lead to genome instability and other long-term health consequences.
This study investigates the interactions between NPs and an immortalized cell line of human colorectal adenocarcinoma cells (Caco-2) by exposing them to various NPs concentrations 50, 100, 400, 800, and 1200 μg/mL). The Caco-2 human epithelial cell line is a prevalent model for studying the intestinal epithelial barrier [4]. Derived from colon cancer, a noteworthy feature of this cell line is its spontaneous differentiation into a monolayer that closely resembles absorptive enterocytes functionally and morphologically, reflecting those found in the intestine.
We assessed potential cytotoxicity using the clonogenic assay and examined NP genotoxicity using the alkaline comet assay and flow cytometry assays (PARP1-dependent apoptosis and cell cycle changes). Our findings indicate a moderate level of NP cytotoxicity observed in the clonogenic assay. Moreover, our preliminary results showed no changes in cell cycle distribution and a minimal increase in the level of apoptotic cells. In addition, no single or double DNA strand breaks were observed. Since we did not observe direct effects, we expect indirect effects mediated by other molecules (e.g., induction of reactive oxygen species (ROS), inhibition of DNA repair mechanisms). To test the likely production of reactive oxygen species by Caco-2 cells in the presence of PNP, DCFDA fluorescent probe staining was performed to determine the level of ROS. After exposure to polystyrene nanoparticles, induction of oxidative stress was observed. We also performed RNA isolation and cDNA synthesis for qPCR assay, which allowed us to check the expression of characteristic genes involved in DNA repair pathways. In particular, critical genes involved in the base excision repair (BER) and DSB repair pathways were downregulated, suggesting a potential impairment of the cell's ability to repair oxidative DNA damage.
This study highlights the sublethal effects of nanoplastics on intestinal barrier cells. It underscores the possible risks of chronic exposure to these environmental contaminants, which can lead to genome instability and other long-term health consequences.
60.
Talarek, Sz.; Adamska, A.; Gawlak, Maciej; Dworakowska, Beata; Nurowska, Ewa
Electrophysiological Assessment of BK Channel Activity in LRRC26-Positive Cells Conference
vol. 44 (suppl.A), 2025, ISSN: 2084-1892.
@conference{nokey,
title = {Electrophysiological Assessment of BK Channel Activity in LRRC26-Positive Cells},
author = {Sz. Talarek and A. Adamska and Maciej Gawlak and Beata Dworakowska and Ewa Nurowska},
issn = {2084-1892},
year = {2025},
date = {2025-06-25},
urldate = {2025-06-25},
journal = {Current Topics in Biophysics},
volume = {44 (suppl.A)},
abstract = {The auxiliary γ1 subunit of the BK channel, LRRC26, is known to dramatically shift the activation voltage of BK channels by approximately 140 mV toward hyperpolarization, enabling channel opening at resting membrane potentials and in the absence of Ca²⁺ [1,2]. While LRRC26 expression has been previously reported in epithelial cells, vascular smooth muscle cells, and certain cancer lines, it has not been observed in neuronal cells.
We investigated, using immunofluorescence and the patch-clamp technique, the expression and functional impact of LRRC26 in various cell types, including breast cancer cells (T47D), prostate cancer cells (LNCaP), rat cerebellar Purkinje neurons, and HEK293 cells co-transfected with BK and γ1 cDNAs. Immunofluorescence confirmed LRRC26 presence across all cell types, including Purkinje neurons, where its expression had not been previously reported.
Single-channel patch-clamp recordings under symmetric K⁺ and 1 EGTA conditions revealed functional BK-γ1 complexes only in LNCaP cells and HEK293 cells expressing both BK and γ1. T47D cells exhibited only rare BK activity, with no evidence of γ1-mediated modulation, even after BK channel transfection. Similarly, Purkinje neurons displayed BK activity only under depolarizing or Ca²⁺ presence conditions, with no signatures of γ1-associated hyperpolarized activation. To examine whether the formation of BK-γ1 complexes could be influenced by metabolic conditions, we investigated the effects of glucose availability in Purkinje cells. However, under glucose-limited conditions, no enhancement in BK-γ1-type activity was observed.
Our findings suggest that while LRRC26 protein is detectable in multiple cell types, its functional coupling with BK channels may be cell-type specific and condition-dependent. This implies that LRRC26 may serve additional, possibly non-membrane-associated, cellular roles beyond its established function as a BK channel auxiliary subunit. ...},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The auxiliary γ1 subunit of the BK channel, LRRC26, is known to dramatically shift the activation voltage of BK channels by approximately 140 mV toward hyperpolarization, enabling channel opening at resting membrane potentials and in the absence of Ca²⁺ [1,2]. While LRRC26 expression has been previously reported in epithelial cells, vascular smooth muscle cells, and certain cancer lines, it has not been observed in neuronal cells.
We investigated, using immunofluorescence and the patch-clamp technique, the expression and functional impact of LRRC26 in various cell types, including breast cancer cells (T47D), prostate cancer cells (LNCaP), rat cerebellar Purkinje neurons, and HEK293 cells co-transfected with BK and γ1 cDNAs. Immunofluorescence confirmed LRRC26 presence across all cell types, including Purkinje neurons, where its expression had not been previously reported.
Single-channel patch-clamp recordings under symmetric K⁺ and 1 EGTA conditions revealed functional BK-γ1 complexes only in LNCaP cells and HEK293 cells expressing both BK and γ1. T47D cells exhibited only rare BK activity, with no evidence of γ1-mediated modulation, even after BK channel transfection. Similarly, Purkinje neurons displayed BK activity only under depolarizing or Ca²⁺ presence conditions, with no signatures of γ1-associated hyperpolarized activation. To examine whether the formation of BK-γ1 complexes could be influenced by metabolic conditions, we investigated the effects of glucose availability in Purkinje cells. However, under glucose-limited conditions, no enhancement in BK-γ1-type activity was observed.
Our findings suggest that while LRRC26 protein is detectable in multiple cell types, its functional coupling with BK channels may be cell-type specific and condition-dependent. This implies that LRRC26 may serve additional, possibly non-membrane-associated, cellular roles beyond its established function as a BK channel auxiliary subunit. ...
We investigated, using immunofluorescence and the patch-clamp technique, the expression and functional impact of LRRC26 in various cell types, including breast cancer cells (T47D), prostate cancer cells (LNCaP), rat cerebellar Purkinje neurons, and HEK293 cells co-transfected with BK and γ1 cDNAs. Immunofluorescence confirmed LRRC26 presence across all cell types, including Purkinje neurons, where its expression had not been previously reported.
Single-channel patch-clamp recordings under symmetric K⁺ and 1 EGTA conditions revealed functional BK-γ1 complexes only in LNCaP cells and HEK293 cells expressing both BK and γ1. T47D cells exhibited only rare BK activity, with no evidence of γ1-mediated modulation, even after BK channel transfection. Similarly, Purkinje neurons displayed BK activity only under depolarizing or Ca²⁺ presence conditions, with no signatures of γ1-associated hyperpolarized activation. To examine whether the formation of BK-γ1 complexes could be influenced by metabolic conditions, we investigated the effects of glucose availability in Purkinje cells. However, under glucose-limited conditions, no enhancement in BK-γ1-type activity was observed.
Our findings suggest that while LRRC26 protein is detectable in multiple cell types, its functional coupling with BK channels may be cell-type specific and condition-dependent. This implies that LRRC26 may serve additional, possibly non-membrane-associated, cellular roles beyond its established function as a BK channel auxiliary subunit. ...
2025 |
Wiktorska, Katarzyna; Medyńska, Katarzyna; Pogorzelska, Anna; Mazur, Maciej: pH-responsive chlorophyll derivatives-modified liposomes for doxorubicin delivery. vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025. (Type: Conference | Abstract | BibTeX)@conference{nokey,Triple-negative breast cancer (TNBC) accounts for approximately 10% of all breast cancer cases and is distinguished by its aggressive clinical behavior and high rates of metastasis. A significant challenge in the treatment of TNBC is the absence of estrogen, progesterone, and HER2 receptors, which excludes the use of receptor-targeted therapies. Thus, systemic chemotherapy with doxorubicin remains a primary treatment approach. The clinical application of doxorubicin is limited due to severe systemic side effects, particularly dose-dependent cardiotoxicity, which often results in therapy discontinuation. Hence, liposomal formulations of doxorubicin have been introduced to reduce off-target toxicity. Building on our recent findings that sulforaphane (SFN) synergistically enhances doxorubicin efficacy and reduces its toxicity in vivo [1], this study aimed to design a novel pH-sensitive liposomal delivery system that enables targeted release of doxorubicin in the acidic tumor microenvironment while limiting release under physiological pH. The innovative aspect of this approach involves the use of natural, non-toxic chlorophyll derivatives—chlorophyll, chlorophyllin, and pheophytin—as pH-responsive release modulators. The proposed mechanism under acidic conditions involves: the reversible protonation of doxorubicin, which weakens its interaction with chlorophyllin and facilitates its diffusion across the liposomal membrane; degradation of lipophilic chlorophyll, localized within the liposomal lipid bilayer, increasing membrane permeability. Liposomes were prepared via the passive loading method and characterized by Dynamic Light Scattering (DLS) - size, polydispersity index (PDI), zeta potential, and drug loading efficacy were determined. Next, drug release profiles were evaluated at pH 7.4 (physiological) and pH 6.5 (tumor-mimicking), revealing enhanced doxorubicin release under acidic conditions while restricting release under physiological pH. .... |
Majewski, Jaroslaw: X-ray synchrotron and neutron scattering studies of biomembrane-protein interactions at air-liquid and solid-liquid interfaces. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{nokey,In nature, lipid membranes perform many living cell functions from selective transport and recognition to simple sequestration. They generally consist of a single phospholipid bilayer or in special cases, such as the lung surfactants, a single monolayer. In the cases discussed here, the lipid membrane will be approximated as a single lipid layer at the air-liquid interface (a surfactant Langmuir layer) or supported single lipid bilayers at the solid-liquid interface. Several surface-sensitive scattering techniques have been developed for probing the structure of such ultra-thin, molecular 2-D arrays of surfactants. These include X-ray reflectometry and in-plane grazing incidence diffraction. Both are particularly challenging to study due to the required horizontality of the sample. I will illustrate the use of X-ray and neutron surface scattering methods to characterize the structures of several types of model membranes. The properties of these soft-condensed, ultra-thin layers are of general interest to a wide scientific audience working in the fields of chemistry and biology since they are relevant to such important areas as bio-mineralization, biosensors, advanced drug delivery systems, and protein-membrane interactions. |
Chorazy, Natalia; Wojnar-Lason, Kamila; Gdula, Anna; Bakker, Diane; Zuurbier, Coert J.; Chlopicki, Stefan; Pacia, Marta Z.: Lipid droplets in vascular dysfunction. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_12,Introduction: Lipid droplets (LDs) are lipid-rich organelles found in most cells, including endothelial cells—the thin layer that lines the interior surface of blood vessels. Although historically LDs were regarded as passive cytosolic inclusions, their active roles in both physiological and pathological processes are now increasingly recognized. The formation of vascular LDs, induced by vascular inflammation or lipid overload, is now considered as a key factor in the pathophysiology of diabetes and cardiometabolic diseases. Sodium-glucose co-transporter 2 inhibitors (SGLT2-I) have shown beneficial effects in treating these conditions. Therefore, we hypothesized that SGLT2-I might directly influence the formation of vascular LDs during inflammation or lipid overload .... |
Gajos, Katarzyna; Petrou, Panagiota; Budkowski, Andrzej: Antigen binding to surface immobilized antibodies: Tof-SIMS examination of the IgG orientation and immobilization stability. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_13,In most biosensors, selective binding of analytes by detecting biomolecules occurs at the interface, which is then converted into a detection signal. Antibodies are often applied as detecting molecules due to their ability to specifically bind antigens. IgG is the most commonly used antibody, having a characteristic Y-shaped structure, consisting of a constant Fc domain and two Fab domains containing antigen-binding sites. Due to its structure, this antibody can adapt on the surface different orientations, which differ in access to the antigen binding sites and as the result in the efficiency of antigen binding. Therefore, the quality of the biorecognition layer, involving, the surface density of detecting molecules, their biological activity, elimination of nonspecific adsorption and layer stability, is crucial for the effective and reliable performance of a biosensor device [1]. Controlling the orientation of antibodies and molecular composition of biorecognition layer is extremely important but still challenging. The IgG orientation is most commonly inferred from indirect methods, prone to high uncertainty. In contrast, antibody orientation can be resolved with ToF-SIMS mass spectrometry, because of the technique surface sensitivity and discrimination of the Fc and Fab domains with different amino acid composition. This method, however, is limited to comparative analysis between samples that hindering an absolute determination of the antibody dominant orientation. In this work, we present the novel approach of surface density dependent studies of antibody orientation with ToF-SIMS and PCA, which allows for direct tracking of orientation changes induced by the increasing molecules surface amount and for an accurate evaluation of the dominant orientation by estimation of share of molecules with head-on and tail-on alignment (fFc fraction) [2,3]. We examined the surface density dependent orientation of antibodies immobilized on silane-modified silicon by physical adsorption (APTES layer) and covalent coupling (APTES layer activated with glutaraldehyde, APTES/GA). Differences in dominant vertical orientations are revealed and discussed in terms of relevant molecule–molecule and molecule–surface interactions. Moreover, the impact of the pH of the IgG solution on the dominant vertical orientation of the antibodies immobilized on APTES and APTES/GA is determined and expressed by the fFc fraction [4]. Additionally, the stability of IgG immobilization on APTES and APTES/GA is examined, depending on the initial IgG surface density, by ToF-SIMS molecular composition analysis and by WLRS real-time monitoring of layer thickness. This analysis surprisingly reveals a partial exchange of IgG molecules with BSA during the surface blocking step [5]. Results of IgG orientation and immobilization stability are juxtaposed with the antigen binding efficiency providing a complete insight into biofunctionalization process..... |
Nowak, Witold; Sokołowski, Grzegorz; Chudy, Patryk; Krzeptowski, Wojciech; Józkowicz, Alicja: Heme and heme oxygenases – novel activities of old friends. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_14,Heme is an essential yet potentially cytotoxic molecule that plays a central role in cellular metabolism, signaling, and development. While its biosynthesis is crucial for mitochondrial function and regulation of some transcription factors, excessive or misregulated heme accumulation, especially of intermediates such as protoporphyrin IX (PPIX), can lead to phototoxicity and oxidative stress. Recent research has shed light on previously underappreciated roles of heme and its degradation enzymes, particularly heme oxygenase-1 (HO-1), in embryonic development, DNA replication, and inflammatory signaling. In mouse preimplantation embryos, increased heme synthesis or inhibition of ferrochelatase disrupts cleavage and sensitizes embryos to light via PPIX accumulation, suggesting that early developmental stages are highly sensitive to perturbations in heme metabolism. Concurrently, HO-1, traditionally viewed as an anti-oxidative enzyme, is now recognized for its nuclear functions, including its role in resolving DNA G-quadruplex (G4) structures [1]. HO-1 deficiency leads to G4 accumulation, replication stress, and impaired nuclear p53 localization, indicating its protective function in genome stability [2]. Furthermore, studies in HO-1-deficient fibroblasts and knockout mice reveal that although interferon-stimulated gene (ISG) expression is enhanced in vivo, their response to proinflammatory stimuli such as TNFα is paradoxically weakened in vitro, likely due to impaired NF-κB and STAT1 signaling [3]. This disruption correlates with defective nuclear transport mechanisms involving PARP1 [3], suggesting a broader role for HO-1 in regulating nucleocytoplasmic trafficking under stress. Collectively, these findings uncover a network of heme- and HO-1-mediated processes that extend far beyond their classical roles, positioning them as critical modulators of early development, genomic integrity, and inflammatory homeostasis. These novel insights into “old friends” open promising avenues for understanding diseases linked to metabolic and inflammatory dysregulation. .... |
Lipiec, Ewelina; Cernescu, Adrian; Chachaj-Brekiesz, Anna; Czaja, Michał; Ghosh, Dhiman; Kaderli, Janina; Kobierski, Jan; Lupa, David; Riek, David Perez‐Guaitaand Roland; Seweryn, Sara; Skirlińska-Nosek, Katarzyna; Sofińska, Kamila; Wnętrzak, Anita; Zenobi, Renato; Szymoński, Marek: Mind the gap! Biomolecules in plasmonic nanocavity. vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISBN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_15,Despite several decades of intense research, the most significant biomolecules including nucleic acids, proteins, and lipids hide many secrets from us. Due to the methodological limitations such as lack of sufficient sensitivity and spatial resolution of conventional analytical approaches, the properties and functionalities of such molecules, heterogeneous at the nanoscale, remain unclear. Hence, to achieve significant progress in the characterization of the molecules of life, intense research on the physics and chemistry of processes occurring in plasmonic nano-gap junctions must be performed, providing solid information on the generation of surface plasmons, near-field confinement of the generated electromagnetic field by the nanojunction/cavity, related optical field enhancement in the close vicinity of the characterized biomolecules, as well as the field enhanced molecule vibronic excitations, Raman scattering, and infrared transitions in the nano-gap junction. All those fundamental subjects are at the base of modern molecular nanospectroscopies, such Tip-Enhanced Raman Spectroscopy (TERS), and Fourier Transform InfraRed nano-spectroscopy (nanoFTIR). Our research involve the nanospectroscopic investigation into the local molecular structure of biologically significant biomolecules. including: i) aggregating Alzheimer’s proteins and peptides to monitor the nanoscale distribution of β-sheet secondary structure for revealing the aggregation pathways [1]. ii) cross-talking amyloid-β and the anti-aggregation drug called bexarotene, which slows down the protein aggregation process via steric effects, largely prohibiting the antiparallel to parallel β-sheet rearrangement [2]. iii) amyloid-β individual aggregates in liquid to improve the TER data quality due to the protective role of solvent, in particular, high heat capacity of liquid reduces the effective temperature of analyte preventing its thermal decomposition [3]. iv) aggregating tau protein for probing the antiparallel to parallel β-sheet rearrangement [4]. v) lipid monolayers for investigating of local molecular distribution, orientation, phase separation, and formation of domains [5]. vi) individual DNA strands to explore nanoscale spectral markers of the Double Strand Breaks formation and DNA conformational transitions ... |
Rajfur, Zenon; Kołodziej, Tomasz; Adamczyk, Olga; Mielnicka, Aleksandra; Wojciechowski, Adam: Development of novel optical microscopy methods to study cell migration. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_16,Cell migration is an important biological phenomenon. It plays a crucial role in many biological processes such as wound healing, tissue engineering, functioning of the immune system or embryo development. However, disruption of molecular mechanisms, controlling cell migration, can lead to pathological conditions such as arthritis, osteoporosis, congenital disorders or cancer metastasis. This highlights that the understanding of molecular mechanisms, that regulate cell migration, can help in the development of novel prevention methods or therapies designed to cure above mentioned diseases. Optical microscopy is one of the major experimental techniques employed in cell migration research. Its main advantage is that it allows studies of live cells behavior in their physiological environment. Recently, a connection of advanced optical microscopy techniques with other experimental methods led to the development of novel experimental approaches to cell migration research. One such development was to combine a confocal microscopy technique, which allows to visualize the cell structure and composition in 3D, providing a look inside the cell, and engineering of elastic, hydrogel cell culture substrates which resulted in the discovery of novel microtubule-based cellular structures [1]. In another similar development, wide-field optical microscopy combined with Optically Detected Magnetic Resonance (ODMR) from microdiamonds and Traction Force Microscopy technique provides the prospect of truly multiparametric investigation of cellular processes in live cells, where the local environmental temperature and cellular tractions can be measured simultaneously [2]. Finally, a combination of wide-field optical microscopy, polymer elastic substrate method and computer aided analysis of large image data sets made it possible to elucidate the complex regulation of cellular morphology [3]. Those developments demonstrate that optical microscopy, in connection with other experimental techniques, can deliver novel, important information about biological systems.... |
Zapotoczny, Bartłomiej; Luty, Marcin; Kotlinowski, Jerzy; Kiel, Annika; Hübner, Wolfgang; Szafranska, Karolina; Ortkrass, Henning; Lekka, Małgorzata; am Esch, Jan Schulte; Huser, Thomas: Correlative AFM–optical nanoscopy for polypharmacy studies in hepatic endothelium. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_17,Polypharmacy, defined as the concurrent administration of five or more pharmaceutical agents, poses a growing health challenge, particularly in aging populations in Europe. The liver, responsible for systemic detoxification, is a key target in understanding the cellular mechanisms underlying adverse drug interactions. In particular, liver sinusoidal endothelial cells (LSECs) mediate hepatic filtration, functioning as the first barrier between circulating blood and the liver parenchyma [1]. To facilitate their sieving function, LSECs are perforated with numerous fenestrations, transcellular pores ranging from 50 to 350 nm in diameter [1]. Fenestrations are dynamic structures that respond rapidly to pharmacological stimuli, making them sensitive indicators of hepatic endothelial function [2,3]. Their size and distribution fall below the resolution limit of conventional light microscopy, necessitating advanced imaging approaches. To investigate the nanoscale effects of polypharmacy on LSEC phenotype, we have developed a correlative microscopy framework that integrates high-speed atomic force microscopy (AFM) with super-resolution structured illumination microscopy (SR-SIM). Our AFM modality provides sub-50 nm lateral resolution with temporal precision below one second, enabling the real-time observation of fenestration dynamics and cell elasticity. Complementarily, SR-SIM enhances visualization of cytoskeletal architecture, offering insight into drug-induced morphological and mechanical remodeling. We further explore the hypothesis that fenestration deformability is functionally linked to the overall cell elastic modulus, particularly under inflammatory or fibrotic conditions. Here, we present our latest findings on drug-induced modulation of LSEC nanomechanics and fenestration morphology, as well as the implementation of a custom-designed AFM-SIM correlative platform. This integrative approach provides new opportunities to unravel the biophysical underpinnings of polypharmacy at the cellular and subcellular levels within the hepatic microvasculature (e.g. Fig. 1)[5]. |
Metwally, Sara; Pabijan, Justyna; Lekka, Małgorzata: The impact of 3D microenvironment rheology on cell invasion accompanied by protein expression changes in cancer spheroids. vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025. (Type: Conference | Abstract | BibTeX)@conference{nokey,The mechanical properties of the tumor microenvironment critically influence cancer progression [1-2]. Recent studies have highlighted that, beyond biochemical cues, physical signals such as matrix stiffness can profoundly influence cell behavior, affecting their proliferation and metastatic potential [3]. In this study, we investigate how the rheology of collagen–hyaluronic acid (Col-HA) hydrogels regulates cell migration and which proteins alter their expression in bladder cancer spheroids. By tuning matrix microstructure and viscoelasticity, we established a 3D platform mimicking the conditions of physiologically relevant extracellular matrix (ECM). Spheroids were formed from human non-malignant cancer cells of the ureter (HCV29), transitional cell carcinoma (T24), and bladder carcinoma (HT1376) cells. The hydrogel's microstructure was characterized using scanning electron microscopy (SEM) and fluorescence microscopy, showing the formation of a highly porous fibrillar microstructure with a high level of Col-HA association in the 3D matrix. The hydrogel rheology was measured using a rotational rheometer working in oscillation mode, applying shear strain at the level mimicking physiological mechanical forces (shear strain γ = 1%, and frequency f = 0.1 ÷ 10 Hz). Stiffness-dependent cell migration was recorded using a light microscope. The migration of cells was significantly larger for T24 cells, which are highly invasive compared to HCV29 and HT1376 cells. Cell migration was accompanied by collagen fiber alignment and the formation of microtracks for cell movement. Correspondingly, Western blots revealed stiffness-dependent modulation of key proteins involved in cell migration. Our findings demonstrate that the mechanical properties of the 3D Col-HA hydrogels directly influence cell migration from the spheroids' surface and depend on hydrogel stiffness and cell phenotype. The obtained results might help understand the relationship between physicochemical and biological properties in the tumor–ECM interactions.... |
Szczepanek-Dulska, Monika; Berghauzen-Maciejewska, Klemencja; Dulski, Kamil; Pogoda, Katarzyna: How tissue stiffness affects microglial migration and morphology . Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025. (Type: Conference | Abstract | BibTeX)@conference{nokey,Microglia, the fundamental immune cells of the central nervous system, are highly dynamic and responsive to the brain's microenvironment. One key factor influencing their behavior is the mechanical stiffness of the surrounding tissue, which alters during aging, neuroinflammation, and disease [1,2]. To investigate microglial mechanoresponsiveness, we cultured HMC3 cells on polyacrylamide (PAA) substrates mimicking a range of physiological and pathological brain stiffnesses (0.2 kPa to 23 kPa), as well as glass. Our study focused on how substrate stiffness affects microglial migration, persistence, and morphology. We classified migrating cells into three distinct fractions based on their mean square displacement (MSD): local (MSD < 20 µm²), moderate (20–350 µm²), and global (>350 µm²) migration. Analysis using a modified persistent random walk (PRW) model [3] revealed that both migration speed and persistence time increased with substrate stiffness, reaching the highest values for substrates with stiffnesses of 5 and 23 kPa. Specifically, cells on stiffer substrates exhibited higher speed (µm/h), greater end-to-end displacement, and longer persistence time, indicating enhanced migratory capacity. Interestingly, the amoeboid morphology often associated with cell`s activation was most prominent at intermediate stiffness (5 kPa), where persistence time was also the highest. Moreover, we observed an increase in population heterogeneity with substrate stiffness: cells appeared more homogeneous on soft substrates, but exhibited greater phenotypic diversity as stiffness increased. These findings suggest that mechanical cues modulate microglial behavior in a stiffness-dependent manner, which may have implications for understanding their role in aging and disease. An exponential correlation was shown between persistence time and cell speed on different substrates, suggesting some optimization of microglia motility under changing stiffness conditions. These findings highlight the importance of mechanical cues in regulating microglial migratory behavior, with potential implications for neurodegenerative disorders, where altered tissue mechanics may affect nerve cell function and immune response. ... |
Sitek, Arkadiusz: Predicting patient health trajectories with foundation models: a new frontier in computational medicine. vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025. (Type: Conference | Abstract | BibTeX)@conference{nokey,Recent advances in computational science including applications in biophysics have laid the groundwork for modeling biological systems as dynamic, data-driven processes. Inspired by these principles, we introduce ETHOS (Enhanced Transformer for Health Outcome Simulation) [1], a novel foundation model designed to predict patient-specific health trajectories based on electronic health records (EHRs). ETHOS adapts the transformer architecture [2], originally developed for natural language processing, to analyze Patient Health Timelines (PHTs), which encode heterogeneous clinical events as structured sequences, analogous to physical state transitions in a dynamic system. Unlike traditional models that require task-specific training or curated labels, ETHOS operates in a zero-shot setting. Once trained on large-scale EHR data, it can forecast future health events such as mortality, readmissions, or length of stay purely based on past information. This forecasting is achieved through generative simulation using Monte Carlo sampling over tokenized timelines, allowing ETHOS to sample a multiverse of plausible patient futures under uncertainty, a concept aligned with probabilistic approaches in statistical mechanics. Our published results demonstrate that ETHOS achieves state-of-the-art performance on multiple clinical benchmarks, including ICU mortality (AUC = 0.93), hospital readmission (Figure 1). Furthermore, the model retains high fidelity even in noisy, incomplete datasets such as MIMIC-IV, highlighting its robustness to data inconsistencies, a critical requirement for clinical deployment [1,3]. Beyond predictive accuracy, ETHOS is designed with interpretability and scalability in mind. By leveraging token-level attention mechanisms and causal modeling, it allows for event-level explainability and simulates counterfactual trajectories under hypothetical interventions. This framework sets the stage for interactive AI agents in healthcare, capable of offering real-time, personalized guidance to clinicians, similar to digital decision-support systems grounded in physical modeling principles. ETHOS exemplifies how concepts from biophysics—such as system dynamics, trajectory simulation, and causal inference, can underpin next-generation AI tools in medicine. We propose this model as a foundational computational framework opening new avenues for translational applications in precision health.... |
Marcinkowska-Gapińska, Anna: Perspectives of the use of hemorheological tests in medical diagnostics. vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025. (Type: Conference | Abstract | BibTeX)@conference{nokey,Introduction: Rheology – the science of the flow of matter and the accompanying phenomena of deformation of real bodies – in relation to biological material it is called biorheology, and in relation to blood – hemorheology. Blood flow through blood vessels is a very complex phenomenon due to the physical and physicochemical properties of blood and the structure and properties of the circulatory system. The rheological characteristics of each material depend mainly on two parameters: viscosity and elasticity. Viscosity is a parameter defining the material's resistance to flow, and elasticity expresses the material's resistance to deformation. Hemorheological tests are based primarily on measurements of whole blood viscosity. The parameters determining the whole blood viscosity are: plasma viscosity, hematocrit, deformability and aggregability of red blood cells. Purpose: This paper presents the results of our own research and a review of literature studies indicating that disorders of whole blood viscosity and plasma viscosity may be an indication for expanding diagnostic tests. Methods: Hemorheological tests are performed "in vitro". Blood is collected in the presence of an anticoagulant (EDTA). Measurements of whole blood viscosity as a function of shear rate are performed using rotational rheometers. Since blood plasma is a Newtonian fluid, its viscosity can be measured using both rotational and capillary viscometers. Additional information about blood rheology can be obtained from non-viscometric oscillatory measurements, also known as dynamic mechanical analysis (DMA). The principle of the oscillatory technique is to determine the amplitude and phase of oscillations of the tested sample subjected to the action of a harmonic force with a controlled amplitude and frequency. The measurement performed using the oscillatory method provides information about the viscoelastic properties of the liquid - two components of the complex blood viscosity. The determination of the aggregability and deformability of blood cells is performed directly using aggregometers and appropriate filters. The deformability of erythrocytes and their ability to orient themselves in the flow are estimated based on measurements of the flow time through capillaries or analysis of the diffraction pattern of transmitted light. Information on the ability of erythrocytes to aggregate and deform can be obtained by mathematical analysis of flow curves based on rheological models containing parameters related to the properties of these erythrocytes. Many models describing fluid flow can be found in the literature. The most commonly used model of the flow curve in hemorheology is the model proposed by Quemada in the late eighties. The advantage of this model is the fact that it was formulated for substances with properties identical to those observed in whole blood, i.e. for a concentrated suspension of particles that can aggregate and does not show the existence of a limiting shear stress. The model takes into account the variability of the shape of blood cells and the formation of aggregates - in both cases due to the change in the maximum packing density. The influence of the specific behavior of erythrocytes is most important in blood flow in the microcirculation. Results: Hemorheological factors such as whole blood viscosity, plasma viscosity, hematocrit, white blood cell count, fibrinogen, lipids and lipoproteins affect blood flow in both macrovessels and microvessels and are strongly associated with incidental cardiovascular events. Increased whole blood viscosity is observed in some neoplastic diseases despite low hematocrit. In the acute phase of stroke, high plasma viscosity and increased ability of erythrocytes to aggregate are observed with simultaneous increase in erythrocyte stiffness. In the case of diabetes, increased viscosity and aggregability of erythrocytes are observed. Studies of correlations between the thermographic image of blood flow in the upper and lower limbs with blood viscosity tests allowed for detection of the first circulatory disorders. In COVID patients elevated blood viscosity was correlated with increased patients mortality. Conclusions: The analysis of changes in physicochemical properties of blood conducted in this study shows how important the hemorheological factor can be in diagnostics. Many aspects of hemorheological functioning of a living organism are not yet known. Measurement techniques are constantly being improved, becoming more accurate, which should enable better use of hemorheological measurements for diagnostics and therapy in the future. |
Bujak, Joanna K.; Kosieradzka, Anna; Wardaszka, Artur; Bednarczyk, Piotr: Expression and functional role of TRPV1 channels in T lymphocytes: implications for immune regulation. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{nokey,Transient Receptor Potential (TRP) channels are a diverse family of cation channels involved in sensory perception, including temperature, pain, and pH sensing [1]. Among them, TRPV1, classically known as a thermoreceptor and pain sensor, has recently garnered interest in immunology due to its expression in various immune cell types [2]. Immune cells often operate under changing environmental conditions, such as fluctuations in temperature, local acidosis, or inflammatory signals factors known to modulate TRPV1 activity [3]. In this study, we focused on the expression and functional relevance of TRPV1 in peripheral blood mononuclear cells (PBMCs), with a particular emphasis on T lymphocytes. Our data demonstrate that TRPV1 is expressed at both mRNA and protein levels in unstimulated PBMCs and T cells. Using Fura-2 calcium imaging, we observed increased intracellular calcium levels upon stimulation with capsaicin (a TRPV1 agonist), indicating the functional presence of TRPV1 channels in these cells. Interestingly, TRPV1 expression appears to decrease following T cell activation, as evidenced by reduced TRPV1 mRNA levels in qPCR analysis and lower capsaicin-induced calcium influx in activated cells. This suggests that TRPV1 expression and function are dynamically regulated in the course of immune activation. Our findings support the hypothesis that TRPV1 may contribute to the modulation of immune responses, potentially linking environmental cues such as temperature, pH, or inflammatory mediators to T cell function. Given the complexity of immune regulation, TRPV1 may represent a novel target for immunomodulatory strategies, particularly in conditions associated with inflammation or altered tissue homeostasis. |
Czamara, Krzysztof; Czyzynska-Cichon, Izabela; Bar, Anna; Stanek, Ewa; Wawro, Mateusz; Pacia, Marta Z.; Berkimbayeva, Zeinep; Marczyk, Brygida; Bragado-García, Elvira; Palma-Guzman, Paloma; Fernandez-Alfonso, María Soledad; Chlopicki, Stefan: Time-dependent reversal of High-Fat Diet-Induced insulin resistance, Perivascular Adipose Tissue biochemical changes in relation to Endothelial (Dys)function. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{nokey,Background: Perivascular adipose tissue (PVAT) is essential in controlling vascular function. Our previous results[1,2] of short high-fat diet (HFD)-induced obesity indicated significant changes in PVAT lipid composition accompanied by endothelial dysfunction only in the abdominal aorta (AA). In contrast, the thoracic aorta (TA) with brown-like PVAT remained unchanged. Prolonged (8 weeks) HFD feeding causes insulin resistance, endothelial dysfunction in both TA and AA and alters PVAT, but these changes can be restored by HFD replacement with a normal diet. Methods and results: A multimodal functional, spectroscopic, and molecular characterization of aortas and PVATs was involved to evaluate the effects of diet reversal after eight weeks of HFD (60 kcal% of fat with 1% of cholesterol). After one week of HFD reversal, full reversal of systemic insulin resistance was observed. Using a magnetic resonance imaging (MRI) technique to characterize endothelial function in vivo, it was found that the endothelial dysfunction in TA was partially reversed after one week, with full recovery requiring at least six weeks (Fig. 1). Conversely, Raman spectroscopy revealed that the lipid unsaturation degree[3] of AA PVAT fully recovered early, which is reflected in Scd1 gene expression assessed by qPCR, while recovery in the TA PVAT was only partial. Delayed reversal was associated with transcriptomic alterations in PVAT, not aorta, manifested by altered gene expression of Insr, Irs1/2, End1 and Gucy1b1, and adipokines (Lep, Nampt and Adipoq)..... |
Kopera, Michał; Bernasińska-Słomczewska, Joanna; Adamkiewicz, Małgorzata; Pieniążek, Anna: Oxidative stress caused by acrolein and glyoxal in mononuclear human blood cells. vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{nokey,Acrolein (ACR) and glyoxal (GO) are highly reactive aldehydes generated endogenously during lipid peroxidation, glycation reactions, and inflammation. Both toxins are found in environmental sources like cigarette smoke, combustion products, and highly processed food. Scientific research confirms a strong link between elevated levels of ACR and GO in the human body and the pathogenesis of various diseases, including atherosclerosis, diabetic complications, neurodegenerative disorders, and kidney diseases [1,2]. Carbonyl compounds promote oxidative stress by modifying essential biomolecules, forming adducts with proteins and nucleic acids (carbonyl stress), and depleting intracellular glutathione (GSH). Among the amino acids, the most likely to bind to these toxins are the thiol groups of cysteine, the amino groups of lysine or arginine, and the imidazole groups of histidine. Protein modifications can lead to a cascade of effects, including cellular dysfunction, damage to organelles, and ultimately, cell death. Another mechanism of toxicity of both aldehydes involves the induction of the production of ROS in cells, which results in a disturbance of the redox balance in cells and the induction of oxidative stress. This study investigated how ACR and GO induce oxidative changes in mononuclear blood cells (MNCs). MNCs isolated from the buffy coat were treated with ACR (30, 60, and 90 µM) or GO (2, 5, 10 mM) for 24 h at 37 °C. After incubation, the levels of ROS and RNS, GSH, and free thiol groups in the cells were determined using fluorometric methods. Spectrophotometric techniques were used to determine the level of free amino groups of protein and catalase activity in cells. Statistical analysis of the obtained results was performed using Statistica v. 13.3 (StatSoft Polska, Kraków, Poland). Exposure to acrolein and glyoxal increased the levels of reactive oxygen nitrogen species in all assays, confirming the induction of oxidative stress. Additionally, we observed a decrease in catalase activity, free amino groups, thiol groups, and GSH levels in cells treated with ACR or GO. The reduction in thiol groups, GSH content, and catalase activity indicates a compromise in redox homeostasis in MNCs treated with ACR or GO. The loss of free thiol groups in the proteins of MNCs treated with ACR and GO may be attributed to ROS oxidation and the binding of these toxins. Furthermore, the reduction in amino groups suggests protein modification due to carbonyl stress and potential adduct formation with reactive aldehydes. Our findings support the hypothesis that aldehyde-induced stress disrupts antioxidant homeostasis in the studied cells. Moreover, the obtained research results confirm the results of previous studies conducted with the participation of both toxins in human erythrocytes [3,4]. The increased levels of ROS and RNS, along with modified protein structures, could have implications for chronic inflammatory and metabolic diseases. It is important to note that acrolein is more toxic than glyoxal. While the changes observed in cells were similar for both toxins, ACR induced these effects at micromolar concentrations, whereas GO required millimolar concentrations... |
Gruszecki, Wieslaw I.: When you look deep into the human eye… A biophysicist's perspective . Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_1,When you look deep into a human eye, you will see a yellow spot. When you carefully examine this part of the retina, you will discover that this color comes from lutein and zeaxanthin, yellow xanthophyll pigments, the same ones found in the chloroplasts of plants. In fact, the very same pigment molecules that we owe to our healthy “green” diet may perform important biological functions, similar in both the photosynthetic apparatus and the eye. The results of the recent studies from our laboratory reveal the operation of very interesting and distinctive for the retina molecular mechanisms based upon the trans-cis photo-isomerization of xanthophylls. During my talk, I will provide an overview of these mechanisms, their physiological consequences, and promote a “colorful” diet that is extremely important for your sharp vision throughout the decades of your life |
Gryczyński, Ignacy: Room temperature phosphorescence with direct triplet state excitation. Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF), vol. 44 (suppl.A), Polish Biophysical Society and Adam Mickiewicz University, ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan, 2025, ISSN: 2084-1892. (Type: Conference | Abstract | BibTeX)@conference{PlenaryLectures2025_2,Although transitions between states of different multiplicity are strongly forbidden, in many cases they have been observed. For example, triplet-singlet transition is forbidden, but phosphorescence is commonly observed and measured. Usually, phosphorescence requires low temperatures, and most measurements are done in liquid nitrogen or helium. However, immobilization of fluorophores in polymers with a low permeability for oxygen often results in easily observable phosphorescence emission at room temperature, phenomenon called RTP. Interestingly, in many cases RTP can be achieved with the direct triplet state excitation at longer wavelengths than absorption. In this lecture a recent achievements in directly excited RTP will be presented. |
1977 |
Kutnik, Jan: Bioelectric potentials of Charophyta cells. In: Zagadnienia Biofizyki Współczesnej, vol. 2, pp. 5-13, 1977, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(2)5-13,Bioelectric potentials are generated due to cell membranes. Two kinds of potentials can be distinguished: resting potential and action potential. Potentials of the Chorophyta cells differ from analogical potentials of animal cells in value, time of duration, velocity of extending and participation of particular ions flowing through the membrane. Resting potentials are of the diffusion kind. Action potentials are explained by the increase in permeability of the membrane for certain kinds of ions. There remain some problems which have not been fully explained yet, e.g. selectivity of membranes, mobility of ions in the membranes, mechanisms acting in membranes in excited state etc. |
Bulanda, Wladyslaw: Electric conductivity of organic compounds and its significance in biology. In: Zagadnienia Biofizyki Współczesnej, vol. 2, pp. 15-41, 1977, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(2)15-42,The paper reviews experimental and theoretical investigations concerning semiconducting properties of organic compounds. Principal parameters of semiconductors and methods of their measurements are presented as well as results of semiconducting parameter measurements of organic compounds and some models explaining electronic conductivity of them are discussed. Semiconducting properties of proteins, nucleic acids, amino acids and the possible occurrence of semiconductivity in biological systems are described. The results of the experiments carried out in the Biophysics Laboratory of Physic's Institute of UMCS in Lublin concerning electronic conductivity in intermodal cells of Characeae are presented. |
Wadas, Romuald: Magnetism in biological molecules. In: Zagadnienia Biofizyki Współczesnej, vol. 2, pp. 43-70, 1977, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(2)43-70,The paramagnetic, antiferromagnetic, ferrimagnetic and ferromagnetic biological molecules were described. The effect of the magnetic properties of biological molecules on metabolic processes was presented. The effect of the externally applied magnetic field on magnetic biological molecules and liquid crystals in living cells was investigated both experimentally and theoretically. |
Jóźwiak, Zofia; Bartosz, Grzegorz: Superoxide dismutase. In: Zagadnienia Biofizyki Współczesnej, vol. 2, pp. 71-98, 1977, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(2)71-98,Superoxide dismutase (oxidoreductase superoxide: E. C. 1.15.1.1) catalyses the reaction of dismutation of superoxide radical anion, 02'. This enzyme is an universal cellular constituent of aerobic organisms. A dimeric metalloprotein of molecular weight of about 33 000 daltons containing Cu and Zn is present in cytosol of eukaryotic organisms. Cu-Zn-superoxide dismutase from bovine erythrocytes is the best characterrized protein of this group and its complete amino acid sequence is established. On the other hand, prokaryotic organisms possess dismutases of different structure, containing either Mn or Fe, of molecular weight of about 40000 daltons. A tetrameric from of Mn-superoxide dismutase (molecular weight of about 80000 daltons) is present in mitochondria of eukaryotes, what has been interpreted' in favour of the theory of endosymbiothic origin of mitochondria. Extensive studies have been performed on the mechanism of action of superoxide dismutase. The enzyme has also been used as a specific probe for involvement of the superoxide radical anion in various enzymatic and non-enzymatic processes. The ubiquitous presence of this enzyme in aerobic organisms suggests its important role as a protective agent against 02-.. |
Chławiczka, Stanisław; Wardas, Władysław: Kinetic formaldehyd metod investigation of DNA secondary structure changes . In: Zagadnienia Biofizyki Współczesnej, vol. 2, pp. 99-110, 1977, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1977(2)99-110,The effect of various physical and chemical factors on the secondary structure of DNA molecules in solution is discussed. The mathematical aspect of interaction DNA·formaldehyd (CH20) and some theoretical principles of the so called kinetic formaldehyd method (KF) are presented. Using the KF method the determination of defect concentration in DNA secondary structure is possible basing on differences in the unwinding velocity of the DNA bihelix observed under action of CH20 when analysed DNA samples have different numbers of structural defects. The detailed procedure of DNA secondary structure investigation by use of this method is presented. Effects of other parameters as chosen wavelength, pH, temperature, kind of DNA and formaldehyde concentration on the characteristic of the obtained KF curves are reviewed and discussed. |
Kanclerz, Andrzej; Zbytniewski, Zbigniew: Application of the electron spin resonance (ESR) technique in oncology . In: Zagadnienia Biofizyki Współczesnej, vol. 2, pp. 111-118, 1977, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1977(2)111-118,During the last years the ESR technique is becoming more and more applicable in the investigations of biological systems. There exists a free-radical theory of oncogenesis which is supported by the findings available by the use of ESR technique. It has been stated that many chemical carcinogens in the cell are transformed into free-radical forms reacting with nucleic acids. In the early stages of carcinogenesis the free-radical level increases, and after the occurrence of the tumour it decreases below the normal level. The observed changes in the free-radical concentrations take place not only in the tumour itself, but also in other tissues of the tumour bearing animals and human beings |
1976 |
Kotłowska, Maria; Kielich, Stanislaw: Determination of the optical and electric properties of biomacromolecules by the method of anisotropic light scattering . In: Zagadnienia Biofizyki Współczesnej, vol. 1, pp. 7-16, 1976, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(1)7-16,Anisotropic light scattering by solutions of biomacromolecules, arrayed in an external DC electric field, is a source of data concerning their dipole moment and anisotropy, both optical and electric. A theory of the effect is proposed for biomacromolecules of linear dimensions l less than incident light wavelength λ (l<1/20 λ) as well for ones of linear dimensions of wavelength order (l ~ λ). Formulae are derived for the relative changes in scattered light intensity versus the square of the external field strength permitting to determine the sign and numerical value (α3 – α1) of the electric anisotropy (α3 - the electric polarizabilitv of the biornacromolecule in the direction of its symmetry axis, α1 - that perpendicular to the latter). Very high external field strengths lead to electric saturation (the biomacromolecutes are completely oriented with their axis of maximal polarizability into the field direction). Relative changes in intensity, scattered at electric saturation, are considered, and formulae are proposed permitting to determine the sign and numerical value of the optical anisotropy of such biomacrornolecules. Cases of reorientation by other external agents (a magnetic field or the electric field of a laser beam) are also discussed. |
Wróbel, Danuta: Spectral methods of investigation of biological systems . In: Zagadnienia Biofizyki Współczesnej, vol. 1, pp. 17-37, 1976, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW1976(1)17-37,In the article various methods used in the study of the biological systems are described. Several methods of radiative transitions spectroscopy such as: vibrational – rotational spectroscopy, spectroscopy of singlet and triplet states, two – photon absorption, electron impact spectroscopy, also degree of polarization and lifetime of the excited states measurements are characterized. Radiationless spectroscopy (internal conversion and intersystem crossing) is reported too. From absorption and fluorescence measurements done on biological systems, the information concerning the structure of biological systems, mutual ordering and shape of biomolecules, interaction and energy migration between them, and the role of individual compounds of live organism in metabolic processes is derived. |
Łazarski, Roman: Natural photoprotectors . In: Zagadnienia Biofizyki Współczesnej, vol. 1, pp. 89-101, 1976, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(1)89-101,Light can be considered one of those environmental factors which are not only beneficial but even indispensable for the existence of life. Nevertheless, one can suppose that photochemical reactions are, as a rule, deleterious if uncontrolled by the organism. Such a point of view is substantiated by numerous experimental data. The present paper describes various ways of this harmful action, including the role of photodynamic effect, and analyses several possible mechanisms of photo-protection. The question is then discussed what are the general features of substances capable of functioning as natural photoprotectors, particular attention being paid to two especially interesting groups of chemical compounds, namely to melanins and carotenoids. In the light of contemporary research, the significance of melanins as protectors against damage produced by electromagnetic waves is manifold. This hold true for both the wavelength (from infrared until gamma radiations) and the mechanisms of action (from simple screening until radical reactions and oxidation-reductions). As regards carotenoids, their radio-protective activity is still disputable and the mechanism of physical careening seems to be of second importance. On the contrary, the photo-protection based on physico-chemical interactions is quite essential for the organism and much better understood. |
Retelewska, Wanda: Effect of ionising radiation on lymphocytes . In: Zagadnienia Biofizyki Współczesnej, vol. 1, pp. 103-121, 1976, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW_1976(1)103-121,Radiation-induced changes of lymphocytes, which belong to the most radiosensitive cells, are described. Depending on the radiation dose, conditions of irradiation and nature of the irradiated object (whole organism or isolated lymphocytes from different tissues) the radiation-induced changes may be of different character. The most frequently observed radiation-induced changes of lymphocytes consist in a partial disappearance of these cells and deterioration of immunologic capacity of irradiated animals. Among the visible morphologic changes preceding the radiation-induced lymphocyte death one should mention: pycnotic degeneration of the cell nucleus, disintegration of mitochondria and cell membranes and cytoplasmic alterations. Radiation affects, first of all, energetic metabolism of the lymphocyte. It is generally suggested that energetic metabolism of the cell nucleus belongs to the first signals of irradiation both in vivo and in vitro. Radiation-induced inhibition of nuclear and mitochondrial oxidative phosphorylation involving a decrease of ATP level precedes other detectable radiaton-induced injuries of the lymphocyte. It has been shown recently that degradation of adenine nucleotides to hypoxanthine begins already in 30 min after irradiation of rat thymocytes, preceding inhibition of ATP synthesis. Oxidative phosphorylation is very sensitive to the action of radiation, however its inhibition is observed not immediately but about 60 min following irradiation of rat thymocytes with a dose of 1000 R. Restoring effect of adenine on radiation-induced damage of rat thymocytes is also rewieved. Adenine added within one hour after irradiation prevents the degradation of ATP to' hypoxanthine and nucleoprotein dissociation. It affects the lymphocyte viability, too. Mechanism of the restoring effect of adenine on nucleotide degradation is not cleared up. The extraordinary sensitivity of lymphocytes to the action of radiation may be utilized in biological dosimetry. On the basis of quantitative alterations induced by radiation in chromosomes of peripheral blood lymphocytes the dose of radiation absorbed by the organism, may be evaluated. |
Bartosz, Grzegorz: Sprawozdanie z V Międzynarodowego Kongresu Biofizyki. 1976, ISSN: 1232-9630. (Type: Miscellaneous | Links | BibTeX)@misc{ZBW_1976(1)123-125, |
Wanik, Barbara; Lidwin, Maria: Optical activity of deoxyribonucleic acid. In: Zagadnienia Biofizyki Współczesnej, vol. 1, pp. 39-54, 1976, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW1976(1)39-54,It is known that the explanations of CD and ORD phenomenon of nucleic acids should take into account rather the base-base interactions than the base-pentose rings interactions. In the light of the neighbour-neighbour approximation theory the base-stacking interaction seems to have the greatest importance. DNA macromolecules in aqueous environments are available to disorganization accompanied by the weakening of basestacking hydrophobic interactions that are reflected in the diminution of the Cotton effect amplitude. The ionic strength of the solution in the range of 5.10-5 - 5.10-3 influences in different ways the stability of the structure of DNA molecule. Basing on the analysis of ORD and CD profiles, DNA molecules in solution of the ionic strength of.5 .10-3 - 1 seem to have the greatest stability. The appearance of new peaks on ORD curves (e.g. as a result of protonation from pH = 7 to pH = 3.5) indicates the existence of an intermediate DNA form not fully native and not completely denatured. The formation of the intermediate DNA structure is probably evoked by conformational changes which occur in the G+C rich fragments of DNA double-helical chains as a result of cytosine protonation. The increase of temperature disrupts the "DNA double-helical structure. This phenomenon can be analyzed through ORD profiles as a function of temperature. The divalent cations (Mg+2, Mn+2, Cu+2, Hg+2, Zn+2) cause some subtle reversible changes in the DNA structure which are reflected in different deformations of the ORD profiles. Sometimes the interactions of divalent cations with DNA macromolecules produce even a lowering of the peaks. The interactions of dyes such as acridine orange or proflavine with DNA macromolecules which form DNA-dyes complexes are accompanied by appearance of new Cotton effects. |
Olichwier-Holwek, Jolanta: Paramagnetic resonance studies of hemoproteins. In: Zagadnienia Biofizyki Współczesnej, vol. 1, pp. 55-88, 1976, ISSN: 1232-9630. (Type: Journal Article | Abstract | Links | BibTeX)@article{ZBW1976(1)55-88,Metallo-proteins, and in particular heme proteins, perform a wide variety of biological functions and have diverse chemical and physical characteristics. Physical methods such as EPR have often been used as aids to determine the electronic state at the heme site in order to relate the structure of the protein at its active site to its chemical function. Home proteins can exist in a variety of oxidation and spin states, each dependent upon the immediate environment of the heme. The oxidation states most commonly encountered are the ferrous and ferric. The states have 6 and 5 magnetic electrons respectively, in the iron-porphyrin system (the d electrons) and it is the geometrical relationship of these magnetic electrons, which is sensitive to the influence of the environment of heme. When examined at low temperatures all heme proteins containing mononuclear high spin ferric heme, exhibit electron paramagnetic resonance (EPR) absorptions extending from near g=6 to g=2 which arise from transients of the lowest Kramers doublet. Absolute quantitation of high spin ferric EPR spectra has to be made from experiments at very low temperature or at the basis of the zero field splitting. The characteristics of the EPR spectrum may be used to describe the symmetry of heme. The incorporation of hemin into a protein constains the heme in such a manner that there is a departure from tetragonal symmetry towards rhombic (gx ≠ gy). In these cases the resonance absorption derivative near g=6 is either broadened or split into two resolvable g values dependent upon the interaction of the protein with heme. Thus, the EPR of high spin heme proteins can be used as a protein conformational probe. |
