Expression of bcl-2 and bax in regenerating rat renal tubules following ischemic injury

Am J Physiol. 1997 May;272(5 Pt 2):F640-7. doi: 10.1152/ajprenal.1997.272.5.F640.


To define potential roles for bcl-2 and bax in adult kidney as regulators of regeneration, their expressions were characterized postischemic injury. A 2.1-fold increase in levels of renal bcl-2 mRNA occurred within 24 h of injury relative to levels in kidney of sham-operated control rats. The levels of bcl-2 mRNA remained elevated for 3 days but returned to baseline by day 5 postischemia. In situ hybridization of kidneys from sham-operated rats demonstrated faint expression of bcl-2 mRNA localized diffusely throughout the nephron. After renal injury, the expression of bcl-2 mRNA was markedly enhanced in regenerating proximal tubule cells relining the basement membrane. Immunohistochemistry showed a similar localization for bcl-2 protein. Levels of bax mRNA in kidney were elevated beginning at 24 h postischemia and remained elevated for 7 days postinjury. Bax mRNA and bax protein were colocalized to regenerating proximal tubules postischemia and were prominently expressed in papillary proliferations. We conclude that the expressions of bcl-2 and bax in kidney are enhanced in a predictable pattern following acute ischemic injury. Our findings suggest that these regulators of apoptosis play key roles in the process of repair of the damaged proximal tubule postischemia.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis
  • Gene Expression
  • Genes, bcl-2*
  • In Situ Hybridization
  • Kidney Tubules / metabolism*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • RNA, Messenger / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Regeneration*
  • Reperfusion Injury / metabolism*
  • bcl-2-Associated X Protein


  • Bax protein, rat
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Messenger
  • bcl-2-Associated X Protein