Heat-shock protein 25 induction and redistribution during actin reorganization after renal ischemia

Am J Physiol. 1998 Jan;274(1):F215-22. doi: 10.1152/ajprenal.1998.274.1.F215.


The small heat-shock proteins appear to have a regulatory role in actin dynamics. Since cytoskeletal disruption is integral to ischemic renal injury, we evaluated expression and intracellular distribution of heat-shock protein 25 (HSP-25) in rat renal cortex after 45 min of renal ischemia. HSP-25 was constitutively expressed and induced by ischemia with peak levels reached by 6 h reflow. Ischemia caused a shift of HSP-25 from the detergent-soluble into the insoluble cytoskeletal fraction. By 2 h reflow, the majority of HSP-25 had redistributed into the soluble fraction. HSP-25 was predominantly localized in a subapical distribution in control proximal tubules, a pattern intermediate between deoxyribonuclease (DNase)-reactive and filamentous actin. After ischemia, HSP-25 dispersed through the cytoplasm with small punctate accumulations similar to DNase-reactive actin. During later reflow, all three proteins were found in coarse intracytoplasmic accumulations; however, HSP-25 and DNase-reactive actin were in separate accumulations. HSP-25 and microfilamentous actin staining returned to the subapical domain. Thus the temporal and spatial patterns of HSP-25 induction and distribution suggest specific interactions between HSP-25 and actin during the early postischemic reorganization of the cytoskeleton. HSP-25 may have additional roles distinct from actin dynamics later in the course of postischemic recovery.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / metabolism*
  • Animals
  • Aorta, Abdominal
  • Cytoskeleton / metabolism
  • Cytoskeleton / pathology
  • Heat-Shock Proteins / biosynthesis*
  • Heat-Shock Proteins / metabolism
  • Ischemia / metabolism*
  • Ischemia / pathology
  • Kidney / blood supply*
  • Kidney / metabolism
  • Kidney / pathology
  • Kidney Tubules, Proximal / metabolism
  • Kidney Tubules, Proximal / pathology
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Renal Artery


  • Actins
  • Heat-Shock Proteins