Molecular and cellular responses to renal injury : a (phospho)-proteomic approach

Abstract

Our kidneys play a major role in regulating the body__s internal environment, via transportation of water, salt, potassium and waste products. As a result of this transport function, cells within the kidney are relatively sensitive to injury. This injury can occur when the kidneys are exposed to anticancer drugs, antibiotics, toxic chemicals or as a result of a drop in blood flow during kidney transplantation (ischemia/reperfusion injury). As a consequence, renal function is rapidly lost. The primary targets for injury are epithelial cells lining the proximal tubule. These cells rest on a basement membrane via cell-matrix interactions and are connected to each other via cell-cell interactions. At these adhesion sites, several signalling complexes are located, which are linked to the F-actin cytoskeleton of the cell. When cells are damaged, they alter or may loose their cell-cell and cell-matrix adhesions in association with reorganization of the actin cytoskeleton. This is associated with changes in the activation status of several signal transduction pathways. The research described in this thesis was designed to identify __new__ signalling pathways involved in renal cell injury and understand their role in this process. The changes in protein expression and phosphorylation that occur in association with changes in cell adhesion and cytoskeletal organization prior to or during renal cell injury were analyzed using 2D-Difference In Gel Electrophoresis (DIGE) and 2D-phosphotyrosine blotting.the protein identifications that are described in this thesis point to a more common observation of alterations in the F-actin cytoskeleton that take place during the process of renal cell injury and regeneration. Assessing the precise role of these proteins and their phosphorylation status will increase our understanding of the events that take place during this process.