Fractal cell volume regulation

ALVAREZ HA, CARLEVARO CM, SCHWARZBAUM PJ, CHARA O

Congreso; Reunion Nacional de Fisica; 2015

Sociedad Argentina de Fisica

Abstract:Cellular volume is tightly regulated in the animal kingdom: cell exposure to ahypotonic or hypertonic media induces an osmotic cell change followed by a cellvolume regulatory response, known as Regulatory Volume Decrease (RVD) orRegulatory Volume Increase (RVI) process, respectively. It has been proposedthat this regulatory response would be based on the existence of a mechanicalsensor by which the cell would continuously monitor its volume. It has beenconceived that this mechanical sensor could be associated with membrane-locatedmechano-sensitive ion channels, cytosolic molecular crowding or even thecytosqueleton. We developed a mathematical model assuming a mechanical sensorof fractal dimension which contemplates these mechanisms. The model is composedby a system of ordinary differential equations (ODEs) describing the dynamicsof cell volume and intracellular solute content and constituting ageneralization of previous models1. By constraining the model withexperimental information of typical conditions of RVD and RVI assays, the modelis able to qualitatively and quantitatively reproduce the phenomenology of theregulatory response. Furthermore, the model predicts a not yet observedoscillatory behavior which can be explained by stability analysis.