Biology subjects

Gaczynska, M.

Publications and source records attributed to Gaczynska, M..

4 recordsLinked to original sources

bioRxiv2026

Strategies of mechanical adaptations of circulating tumor cells and properties of their cellular microenvironment have predictive and prognostic biomarker value

Mechanically demanding conditions in the blood circulation damage and kill majority of tumor-shed circulating tumor cells (CTCs). Mechanical fitness: a set of mechanical properties detected with atomic force spectroscopy based force spectrometry supports survival of CTCs. We propose that live CTCs isolated from peripheral blood of prostate cancer patients represent distinct strategies of fitness promoting mechanical adaptations to the fluid shear stress. Some of the cells mimicked properties of erythrocytes (high stiffness) or leukocytes (high deformability). The clustering strategy characterized by exceptionally high adhesion is ingenious to CTCs and not found in blood cells. The abundance of CTCs with elevated adhesion has a predictive value for prostate cancer patients starting first round of androgen deprivation therapy. Moreover, a high adhesion score based on individual cells or average patient-specific adhesion is instrumental to stratify recurrent patients that underwent diagnostic imaging by PSMA-PET/CT and clarify inconclusive PSMA scan results. Including contribution of erythrocyte-like strategy broadened the predictive power of CTC mechanophenotyping. Improved biomarking opportunities to predict early castration resistances were noted when the composition of CTC microenvironment was included alongside the mechanical properties. We demonstrated previously that the CTC microenvironment is formed by large cells co-purifying by microfiltration of the blood of cancer patients. Analysis of the association of particular components of CTC microenvironment with the clustering strategy led to pointing at highly adhesive CTC-EMT. However, in the advanced patients adhesiveness of CTC-EMT was surpassed by tumor hybrid cells (THCs), a distinctive kind of invasive species formed by incomplete phagocytosis of CTCs by macrophages. THCs changed their mechanical phenotype and strategy preference with disease progression pointing at the dynamic nature of adaptations of tumor-shed cells to circulation conditions.

cancer biology↗

bioRxiv2026

Multivalent Adhesive Probe Atomic Force Microscopy (MAPA) for accessing dispersive adhesion of cells and biosurfaces.

Adhesion of cells is the key factor determining functioning of multicellular organisms. Viscoelastic properties of cells can be studied by multiple methods. However, attractiveness of cells or extracellular matrix without the elastic component (dispersive adhesion) is not accessible. We present an extension of force spectrometry technology: the Multivalent Adhesive Probe Atomic Force Microscopy (MAPA) that delivers dispersive adhesion maps of live cells and biosurfaces, and identifies differences unresolved by viscoelastic probing.

biophysics↗

bioRxiv2024

β-Amyloid impairs Proteasome structure and function. Proteasome activation mitigates amyloid induced toxicity and cognitive deficits

BackgroundImpaired proteasome activity is a robust and reproducible feature in Alzheimers disease (AD) patients and animal models. Although amyloid beta (A{beta}) may inhibit proteasomes, it is unclear if this reflects direct structural interference or indirect toxicity. The proteasome controls a myriad of critical neuronal processes with its disruption potentially driving downstream AD pathology. MethodsWe examined the direct impact of distinct A{beta} forms on proteasome structure, dynamics, and function by evaluating enzyme activity and morphology by atomic force microscopy (AFM) and native-gel electrophoresis. To prevent A{beta}-induced impairments in vitro and in AD animal models, we used allosteric proteasome activating peptidomimetics. We characterized their interactions with proteasome by AI enhanced in silico docking. ResultsToxic soluble A{beta}42 oligomers selectively inhibit 20S and 26S proteasome activity, while monomeric and fibrillar forms and A{beta}40 show minimal inhibitory effects. Morphometric analysis of AFM images suggests A{beta}42 oligomers bind laterally to the 20S proteasomes, and impair proteasome dynamics by disabling gate opening, critical for catalytic activity. Oligomer-decorated proteasomes are locked in catalytically inert cycling between closed and intermediate gate conformations. Oligomeric A{beta}42 also induces disassembly of the 26S complex, increasing content of free 20S cores. Importantly, we show proteasome dysfunction induced by oligomeric A{beta}42 is both preventable and reversible by employing an allosteric proteasome activator TAT-DEN, promoting gate opening and restoring enzymatic activity with the full-cycle of conformational transitions in oligomers-treated proteasomes. In cellular and animal models, restoring proteasome function via TAT-DEN mitigated A{beta}-induced cell death, spatial learning/memory deficits, and survival impairments, even under conditions of pre-established A{beta} deficits. ConclusionsOligomeric A{beta}42 decorates the lateral sides of the 20S proteasome restricting cycling between conformations and blocking gate opening. It also reduces the pool of 26S proteasomes necessary for the ubiquitin-dependent protein degradation. We demonstrate proteasome dysfunction can be prevented and reversed by proteasome agonist that lowers 20S affinity to oligomers and promotes allosteric gate opening. We show that proteasome activation with TAT-DEN prevents cognitive deficits in AD animal models. This suggests proteasome dysfunction is a key downstream target in AD pathology and supports proteasome activation as a therapeutic strategy to restore neuronal function in AD.

molecular biology↗

bioRxiv2021

Endometrial Gap Junction Expression - Early Indicators of Endometriosis and Integral to Invasiveness

Endometriosis is an invasive disease, and a leading cause of pain, infertility and disability among women, with an incidence 10 fold that of cancer. A more complete understanding of disease pathogenesis is essential for the development of non-surgical diagnostic assays and non-hormonal therapeutics. Avoidance of immune clearance and implantation of endometrial tissue on peritoneal surfaces are features of endometriosis lesion formation that overlap with cancer metastasis. Connexins, and the gap junctions they form, have been implicated in cancer progression, and may be associated endometriosis pathophysiology. Single cell transcriptomic profiling of endometrial epithelial and stromal cells from women with endometriosis reveals a striking and progressive shift in expression of connexins and related regulatory and junctional genes. We demonstrate that gap junction coupling between endometrial cells and the peritoneal mesothelium is dramatically induced, specifically in endometriosis patients, and is required for invasion by inducing breakdown of the mesothelial barrier function.

cell biology↗