bioRxiv Science⌕ Search

Biology subjects

Tcarenkova, E.

Publications and source records attributed to Tcarenkova, E..

3 recordsLinked to original sources

Heat stress sensitizes zebrafish embryos to neurological and cardiac toxicity.

Global warming increases the risk of dangerous heat waves, which may have deleterious effects on humans and wildlife. Here, we have utilized zebrafish embryos as a model to analyse heat stress and effect of chemical compounds on responses to heat stress. The temperature adaptation limit of zebrafish embryos was 37{degrees}C in behavioural test and 38{degrees}C in cardiac test. Polyaromatic hydrocarbon phenanthrene completely blocked the behavioural adaptation to heat stress. Interestingly, the cardiotoxic effects of lapatinib, phenanthrene and paclitaxel were induced by heat stress. Taken together, our data indicates that motility and cardiac function of zebrafish embryos can be utilized as a model to analyze modulatory effects of compounds on heat stress. HighlightsO_LIZebrafish embryos can be utilized as an in vivo model for acute heat stress C_LIO_LIPhenanthrene inhibited motility increase upon heat stress C_LIO_LICardiotoxicity of lapatinib, paclitaxel and phenanthrene was potentiated by heat stress C_LI

pharmacology and toxicology↗

Vimentin supports directional cell migration by controlling focal adhesions

Persistent cell migration requires focal adhesions to assemble and disassemble locally while maintaining global front-rear alignment. The mechanism that enforces this long-range spatial coherence remains unresolved. Here we identify the intermediate filament protein vimentin as a cell-scale organizer that stabilizes focal adhesion alignment during directed fibroblast migration. Using quantitative live-cell imaging, we show that vimentin-deficient fibroblasts lose directional persistence and a complete collapse of global focal adhesion alignment. Quantitative analysis reveals that vimentin stabilizes focal adhesion alignment by constraining angular fluctuations and preserving the periodic bias of adhesion birth across the adhesion field. Loss of vimentin results in smaller, rapidly turning-over adhesions with disrupted orientation. Trajectory analysis reveals a mechanically anchored adhesion state selectively associated with vimentin recruitment, distinguishing mechanical stabilization from biochemical maturation. Super-resolution and iPALM imaging further show that vimentin integrates within the focal adhesion nanoarchitecture near the force-transduction layer. Together, our findings establish that vimentin intermediate filaments impose spatial coherence on adhesion dynamics, converting locally stochastic adhesion assembly, turnover, and disassembly into globally coordinated adhesions and persistent directional migration.

cell biology↗

Easy Two-Photon Image Scanning Microscopy with SPAD Array and Blind Image Reconstruction

Two-photon excitation (2PE) microscopy is the imaging modality of choice, when one desires to work with thick biological samples, possibly in-vivo. However, the resolution in two-photon microscopy is poor, below confocal microscopy, and the lack of an optical pinhole becomes apparent in complex samples as reduced quality of optical sectioning. Here, we propose a straightforward implementation of 2PE image scanning microscopy (2PE-ISM) that, by leveraging our recently introduced ISM platform - based on a new single-photon avalanche diode array detector - coupled with a novel blind image reconstruction method, is shown to improve the optical resolution, as well as the overall image quality in various test samples. Most importantly, our 2PE-ISM implementation requires no calibration or other input from the user - it works like any old and familiar two-photon system, but simply produces higher resolution images (in real-time). Making the complexity disappear, in our view, is the biggest novelty here, and the key for making 2PE-ISM mainstream.

bioengineering↗