Induction of calcyclin after ischemic injury to rat kidney

Genes differentially expressed after acute renal ischemic injury were identified using differential display-polymerase chain reaction (DD-PCR). Messenger RNA for calcyclin, a member of the S100 family of calcium-binding proteins, is increased in kidneys by 6 h following ischemic injury to rats compared with sham surgery. The level of calcyclin mRNA is increased 10-fold by 1 day postinjury and declines thereafter. In situ hybridization demonstrates little calcyclin mRNA in kidneys of sham-operated rats. However, calcyclin protein is present in glomeruli and distal tubules (DT). Compared with kidneys from sham-operated controls, both calcyclin mRNA and protein expression are increased at 1-3 days following ischemic injury in the thick ascending limb of Henle, the DT, and in damaged regenerating segments of proximal tubules. By 7 days postischemia there is a reduction in mRNA and protein expression. Calcyclin could play a role in the regulation of renal cell proliferation and regeneration in the recovery process after acute ischemic injury.