Erschienen in:
01.04.2006 | Original Article
Upregulation of nestin, vimentin, and desmin in rat podocytes in response to injury
verfasst von:
Jun Zou, Eishin Yaoita, Yusuke Watanabe, Yutaka Yoshida, Masaaki Nameta, Huiping Li, Zhenyun Qu, Tadashi Yamamoto
Erschienen in:
Virchows Archiv
|
Ausgabe 4/2006
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Abstract
Podocytes in the renal glomerulus express unusual intermediate filament (IF) proteins for epithelial cells. To gain insight into the role of IF proteins in podocytes, we investigated the expression of nestin, vimentin, and desmin in puromycin aminonucleoside (PAN) nephrosis. A Western blot analysis for nestin, vimentin, and desmin demonstrated their exclusive expression in glomeruli and showed their increase in expression in nephrotic glomeruli. Immunolocalization studies showed nestin and vimentin to be located predominantly in the podocytes in both normal and nephrotic glomeruli and that enhancement of desmin staining only occurred in podocytes. A ribonuclease protection assay showed high levels of vimentin and nestin expression in normal glomeruli and an upregulation of all three IF transcripts in nephrotic glomeruli. One day after the PAN injection, however, the vimentin transcripts were found to already have significantly increased, whereas those of nestin or desmin showed no such increase. These findings indicate that podocytes express three IF proteins, namely, vimentin, desmin, and nestin, which are differentially regulated in response to injury. An upregulation of IF proteins may increase the mechanical stability of cells, thus enabling podocytes to undergo morphological changes on the tensile glomerular capillary wall.