Effect of ischemia on localization of heat shock protein 25 in kidney

The effects of renal ischemia on the intracellular distribution of the low-molecular weight heat shock protein (HSP)25 were examined using immunofluorescence microscopy. In all kidney zones, ischemia decreased HSP25 in the supernatant of the tissue homogenates and increased it in the pellet fraction (containing mainly nuclei and cytoskeletal components). This was associated with disappearance of HSP25 staining from the brush border of proximal convoluted tubule (PCT) cells. Because no nuclear staining of cortical tubule cells was apparent either in control or ischemic kidneys, ischemia seems to cause a closer association of HSP25 with cytoskeletal components. HSP25 probably participates in the postischemic restructuring of the cytoskeleton of PCT cells.