Alterations in intermediate filament proteins in rat kidney proximal tubule epithelial cells.

Changes in the intermediate filament composition of rat kidney proximal tubule cells in culture have been investigated. The data suggest that differentiated tubular epithelial cells do not express vimentin, but vimentin expression is induced when the cells begin to proliferate in culture. The cultured cells are positive for both cytokeratins and vimentin by immunofluorescence microscopy. The data support the concept that the intermediate filament composition of proximal tubule epithelial cells can be altered during proliferation induced by nephrotoxic chemicals or by neoplastic transformation.