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Rajput, A. S.

Publications and source records attributed to Rajput, A. S..

2 recordsLinked to original sources

Spatiotemporal mapping of endothelial proliferative response in acute chemical liver injury

Endothelial cells are major contributors to liver injury response, regeneration, and chronic liver disease. Previous studies identified a proliferative endothelial response to acute liver injury; however, a comprehensive characterization of this adaptive response is missing. We have developed a novel pipeline for spatiotemporal analysis of proliferative response in the liver. We demonstrate that endothelial cells enter the cell cycle upon acute centrilobular injury with a delay compared to hepatocytes and in a spatially distinct pattern from hepatocytes. We show that endothelial cycling predominantly occurs in the pericentral zone, while hepatocyte cycling occurs uniformly throughout the lobule. Endothelial cycling in injured livers leads to heightened clonal expansion, and to serial division rarely observed in homeostatic livers. Consequently, injured lobules exhibit endothelial overabundance during regeneration. Our study provides an in-depth characterization of endothelial proliferative response to liver injury and establishes a novel pipeline for spatiotemporal mapping of hepatic cell states.

cell biology↗

Active geometrodynamics predicts the emergence of cytokinesis

Cell division accomplishes the segregation of genetic material and involves remarkable changes in the cellular geometry culminating in cytokinesis: the cleavage of a mother cell giving rise to two daughter cells. Cytokinesis in animal cells is driven by flows resulting from cortical tension gradients in the actomyosin cortex. Here, we combine a theory for the active geometrodynamics of the cortical surface and quantitative measurements in the C. elegans zygote to reveal the physical principles of cytokinesis. At high activity, we observe the spontaneous emergence of ring-like patterns of myosin concentration and cell shape in the theory. The constriction dynamics of this self-organized pattern agrees with the ingression of the cytokinetic furrow and concomitant myosin accumulation during the first division in the C. elegans embryo. Through RNAi perturbations, we quantitatively test our theoretical predictions of myosin accumulation rates linearly varying with the ingression rate, and the emergence of asymmetric ingression. Our work suggests that the self-organised geometrodynamics of active fluid surfaces underlies cytokinesis.

biophysics↗