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Vishen, A. S.

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

2 recordsLinked to original sources

Injury-induced electrochemical coupling triggers regenerative cell proliferation

Organ injury triggers non-neuronal electric currents essential for regeneration. Yet, the mechanisms by which electrical signals are generated, sensed and transmitted upon damage to promote organ growth remain unclear. Here, we uncover that organ regeneration relies on dynamic electrochemical coupling between tissue-wide depolarization and intracellular proliferative signalling. By sub-second live imaging of injured zebrafish larval fins, we identify events across timescales: a millisecond tissue depolarization gradient, followed by seconds-persistent intracellular Calcium responses. Subsequently within one hour, Voltage Sensing Phosphatase activity translates depolarisation into proliferation. Connecting these timescales with an electro-diffusive model showed that ionic fluxes and electric potential become coupled in the fins interstitial space, enabling organ-wide signal spreading. Our work reveals the coupling between fast electrical signals and slower intracellular signalling, ensuring organ regeneration.

biophysics↗

A mechano-osmotic feedback couples cell volume to the rate of cell deformation

Mechanics has been a central focus of physical biology in the past decade. In comparison, the osmotic and electric properties of cells are less understood. Here we show that a parameter central to both the physics and the physiology of the cell, its volume, depends on a mechano-osmotic coupling. We found that cells change their volume depending on the rate at which they change shape, when they spread, migrate or are externally deformed. Cells undergo slow deformation at constant volume, while fast deformation leads to volume loss. We propose a mechano-sensitive pump and leak model to explain this phenomenon. Our model and experiments suggest that volume modulation depends on the state of the actin cortex and the coupling of ion fluxes to membrane tension. This mechano-osmotic coupling defines a membrane tension homeostasis module constantly at work in cells, causing volume fluctuations associated with fast cell shape changes, with potential consequences on cellular physiology.

biophysics↗