Research Papers

Glomerular podocytes are essential for blood filtration in the kidney underpinned by their unique cytoskeletal morphology. An increasing number of kidney diseases are being associated with key podocyte abnormalities. The Wilms tumour suppressor gene WT1 encodes a zinc finger protein with a crucial role in normal kidney development; and in the adult, WT1 is required for normal podocyte function. Denys Drash Syndrome (DDS) results from mutations affecting WT1’s zinc finger domain. The aim of this study was to undertake, for the first time, a proteomic analysis of cultured human podocytes; and to analyse the molecular changes in DDS podocytes. The morphology of DDS podocytes was highly irregular, reminiscent of a fibroblastic appearance. A reference 2D gel was generated, and 75 proteins were identified of which 43% involved in cytoskeletal architecture. The DDS and wild-type proteomes were compared by 2D DiGE. The level of 95.6% of proteins was unaltered; but 4.4% were altered > 2-fold. A sample of proteins involved in cytoskeletal architecture appeared to be misexpressed in DDS podocytes. Consistent with this finding, overall levels of filamentous actin also appeared reduced in DDS podocytes. We conclude that one of WT1’s functions in podocytes is to regulate the expression of key components and regulators of the cytoskeleton.