Increased resistance to myocardial ischemia in the Brown Norway vs. Dahl S rat: role of nitric oxide synthase and Hsp90.
Hearts from Brown Norway (BN/Mcw) rats are more resistant to ischemia than hearts from Dahl S (SS/Mcw) rats. We determined whether nitric oxide (.NO) is responsible for increased cardioprotection in BN/Mcw vs. SS/Mcw hearts. Hearts from the two strains were treated with N(G)-monomethyl-L-arginine (L-NMA) or S-nitrosoglutathione (GSNO) before ischemia and reperfusion. Infarct size in untreated BN/Mcw hearts was approximately 63% less than in SS/Mcw hearts. Inhibiting NOS with L-NMA increased infarct size in BN/Mcw hearts to that observed in untreated SS/Mcw hearts but did not further increase injury in SS/Mcw hearts. The .NO donor GSNO decreased infarct size in SS/Mcw rats but had no effect on BN/Mcw hearts. Plasma and heart tissue from BN/Mcw rats contained 80% and 130% more nitrite + nitrate than that from SS/Mcw rats. These data suggest that increased .NO production protects BN/Mcw hearts from ischemic injury. Real time PCR showed no differences in NOS1, NOS2 or NOS3 isozyme transcripts in the hearts from the two strains. NOS3 was the only isozyme detected by western analysis. Both strains exhibited the same level of NOS3 and hsp90 protein expression. However, hsp90 association with NOS3 in BN/Mcw hearts was increased twofold compared with SS/Mcw hearts. Inhibiting hsp90-NOS3 interaction with geldanamycin decreased the resistance to ischemia in BN/Mcw hearts but not in SS/Mcw hearts. SS/Mcw hearts also generated three times more N(omega)-nitro-L-arginine-methylester inhibitable superoxide than BN/Mcw hearts. These findings indicate that hsp90 with NOS3 increases .NO production and decreases uncoupled NOS3 activity. We conclude increased association of hsp90 with NOS3 is a major mechanism by which BN/Mcw hearts are more resistant to ischemia than SS/Mcw hearts.
Shi
Yang
Y
Division of Pediatric Surgery, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA. yangshi@mcw.edu
Hutchins
William
W
Ogawa
Hitoshi
H
Chang
Chung-Che
CC
Pritchard
Kirkwood A
KA
Zhang
Chenyang
C
Khampang
Pawjai
P
Lazar
Jozef
J
Jacob
Howard J
HJ
Rafiee
Parvaneh
P
Baker
John E
JE
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000201:enzymology* / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats; D011914:Rats, Inbred BN; D020303:Rats, Inbred Dahl; D013045:Species Specificity; D013481:Superoxides / Q000378:metabolism; D019323:omega-N-Methylarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D018841:HSP90 Heat-Shock Proteins; D009419:Nerve Tissue Proteins; D009566:Nitrates; D009573:Nitrites; D012333:RNA, Messenger; D013481:Superoxides; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496322:Nos1 protein, rat; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat