Regulation and Localization of HSP70 and HSP25 in the Kidney of Rats Undergoing Long-Term Administration of Angiotensin II

Abstract
Various renal insults result in induction of heat shock protein (HSP) expression within the kidney. Some of the HSPs induced in that manner are postulated to have renoprotective effects via either chaperoning actions or antioxidative properties. We have previously reported that long-term angiotensin (Ang) II administration induces the expression of renal HSP32, also known as heme oxygenase-1 (HO-1). Here, we investigated the regulation of expression and localization of other HSPs, including HSP70, HSP25, and αB-crystallin, in the kidney of rats undergoing long-term administration of Ang II (0.7 mg · kg−1 · d−1). Immunoblot analysis demonstrated that Ang II increased renal expression of HSP70 and HSP25, as well as HO-1, but that expression of αB-crystallin was unaffected by this treatment. The Ang II–induced increase in renal HSP70 and HSP25 was dependent on the angiotensin type 1 receptor activation but not on hypertension per se. Immunohistochemistry revealed that HSP70 and HSP25 were expressed in the me...