Monoclonal antibody p-31 recognizes a novel intermediate filament -associated protein (p250) in rat podocytes. Kurihara, Hidetake, Norio Sunagawa, Tatsuo Kobayashi, Kazuhiro Kimura, Nobuo Takasu, and Tsutomu Shike. Shionogi Research Laboratories, 5-12-4 Sagisu, Fukushima-ku, Osaka 553, Japan
APStracts 5:0031F, 1998.
The visceral glomerular epithelial cells (GECs) or podocytes of the renal glomerulus constitute a highly specialized epithelium. To study the nature of podocytes, we established mouse monoclonal antibodies against GEC. Clone P-31 reacted exclusively with the cytoplasm of GEC by immunofluorescence. Immunoblot analysis with P-31 showed that a single band of 250 kD was detectable in a glomerular lysate. The 250 kD polypeptide (p250) was recovered from TX-100-insoluble fractions of isolated glomeruli, suggesting that this molecule is associated with the cytoskeleton. Immunogold staining with P-31 demonstrated that the gold particles were located at the intersections of vimentin-type intermediate filaments of podocytes. In developing kidney, this protein first appeared in immature GECs during the S -shaped body stage. In puromycin aminonucleoside nephrosis, P-250 was dramatically increased in glomeruli where enhanced desmin expression was observed in GECs. These results indicate that P-250 is a novel intermediate filament-associated protein and plays a role in the organization of the intermediate filament network in both normal and diseased conditions.

Received 31 July 1997; accepted in final form 19 January 1998.
APS Manuscript Number F257-7.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 19 February 1998