Regulation and localization of HSP70 and HSP25 in the kidney of rats undergoing long-term administration of angiotensin II.
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 alphaB-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 alphaB-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 medullar regions and in the renal arterial wall in the kidney of control rats. After Ang II infusion, signals for HSP70, HSP25, and HO-1 proteins increased in intensity in the endothelium and medial smooth muscle of the renal artery. In addition, all of these HSPs were induced in proximal renal tubular epithelial cells from the same segments, suggesting that similar mechanisms are responsible for upregulating these HSPs. Our data show that Ang II infusion induces renal HSP70 and HSP25, as well as HO-1, and that Ang II can induce expression of these HSPs in renal cells in a pressor-independent manner.
Ishizaka
Nobukazu
N
Department of Cardiovascular Medicine, University of Tokyo, Graduate School of Medicine, Tokyo, Japan. nobuishizka-tky@umin.ac.jp
Aizawa
Toru
T
Ohno
Minoru
M
Usui Si
Shin-ichi
S
Mori
Ichiro
I
Tang
Shiow-Shih
SS
Ingelfinger
Julie R
JR
Kimura
Satoshi
S
Nagai
Ryozo
R
D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D003459:Crystallins / Q000096:biosynthesis / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000378:metabolism*; D006360:Heat-Shock Proteins; D006427:Hemin / Q000494:pharmacology; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism*; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism*; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000494:pharmacology
D003459:Crystallins; D055551:HSP27 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C486114:Hspb1 protein, rat; D009363:Neoplasm Proteins; D014665:Vasodilator Agents; D000804:Angiotensin II; D006427:Hemin; D009638:Norepinephrine