LABLlLABORATORY OF CELLULAR BIOCHEMISTRY

 

Director: Dra. Silvia Chifflet

 

One of the main objectives of our research group is to study the molecular nature of the mechanisms mediating the interactions between the plasma membrane potential (PMP) and the organization of the cytoskeleton in transport epithelia. In this respect, we have shown that modifications in the PMP of several cultured epithelia exhibiting well-developed adherens junctions provoke characteristic changes of the actin and tubulin cytoskeletons. As a physiological implication of these findings we have also reported that PMP depolarization occurs at the leading edge cells in wounds of corneal endothelial cell monolayers. This spontaneous depolarization participates in the development of the characteristic actin reorganization experienced by the healing cells. In this latter work we have also communicated results showing that the spontaneous depolarization experienced by the cells at the wound border is determined by an increase in the activity in the epithelial sodium channel (ENaC). Taken together, these results contribute to the idea that the PMP of non-excitable cells is an intermediate of diverse cellular signaling processes. Based upon these precedents, our specific topics of immediate interest are: a) to establish the molecular nature of the signaling paths between the modifications in the plasma membrane potential and the rearrangement of the cytoskeletal components, and b) to investigate the nature of the increase in ENaC activity during wound healing in epithelia and the signaling paths involved. Long-term topics of interest of our research group include the investigation of other epithelial processes related to membrane potential modifications and the relevance of our findings to epithelial pathology.