150-kDa oxygen-regulated protein attenuates myocardial ischemia-reperfusion injury in rat heart.

Early contractile dysfunction and the later death of cardiomyocytes are two major problems that can follow myocardial infarction or major cardiovascular surgery that demands ischemic arrest of the heart. Here, we found that 24 h of hypoxia and 1 h of reoxygenation induced the expression of the chaperone ORP150 in cultured rat cardiomyocytes. Inhibition of its induction using an adenovirus to express anti-sense ORP150 significantly enhanced the hypoxia-reoxygenation-induced cardiomyocyte death; cell death was reduced by overexpressing ORP150. Decreased levels of ORP150 expression also enhanced caspase-3 and -8 activation, cytochrome-c release, and DNA fragmentation, suggesting that this chaperone regulates apoptotic cell death. In contrast, increasing the expression of ORP150 in the cardiomyocytes had the opposite effect on the expression of these molecules. Moreover, apoptotic cell death initiated by myocardial ischemia-reperfusion (I/R) was significantly inhibited in vivo by transfecting an ORP150 expression plasmid into whole rat heart using the hemagglutinating virus of Japan (HVJ)-liposome method. Interestingly, ORP150 seemed to preserve calcium homeostasis in cardiomyocytes that underwent ischemia-reoxygenation in vitro. Calpain activity in the cardiomyocytes was enhanced by anti-sense ORP150 and suppressed by sense ORP150. Finally, we examined the functional recovery of rat hearts that overexpressed ORP150 or GFP protein and were subjected to I/R; we found that ORP150 preserved early contractile function after transient ischemia. Our results indicated cytoprotective roles for ORP150 in rat heart and suggested a therapeutic role for the protein both in preventing cardiomyocyte death and in preserving contractile function after ischemic damage.

Aleshin AN ，Sawa Y ，Kitagawa-Sakakida S ，Bando Y ，Ono M ，Memon IA ，Tohyama M ，Ogawa S ，Matsuda H ... -  《JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY》

Allopurinol modulates reactive oxygen species generation and Ca2+ overload in ischemia-reperfused heart and hypoxia-reoxygenated cardiomyocytes.

Kang SM ，Lim S ，Song H ，Chang W ，Lee S ，Bae SM ，Chung JH ，Lee H ，Kim HG ，Yoon DH ，Kim TW ，Jang Y ，Sung JM ，Chung NS ，Hwang KC ... -  《EUROPEAN JOURNAL OF PHARMACOLOGY》

Effects of mouse recombinant bone morphogenetic protein-7 transfection on cell apoptosis, NF-kappaB, and downstream genes in cultured primary cardiomyocytes after simulated ischemia and reperfusion injury.

Xu JH ，Zhao YY ，Wang JK ，Yuan ZG ，Zhang TZ ... -  《-》

Ischemic preconditioning protects cardiomyocytes against ischemic injury by inducing GRP78.

Shintani-Ishida K ，Nakajima M ，Uemura K ，Yoshida K ... -  《BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS》

Effect of hypoxia-inducible factor 1-alpha on hypoxia/reoxygenation-induced apoptosis in primary neonatal rat cardiomyocytes.

We studied the role of hypoxia-inducible factor 1-alpha (HIF-1α) in hypoxia/reoxygenation (H/R)-induced apoptosis in primary neonatal rat cardiomyocytes and its possible molecular mechanisms. Isolated neonatal and adult rat cardiac myocytes were cultured for 48h and were submitted to 5h of hypoxia followed by 2, 6, or 12h of reoxygenation. Small interfering RNA was used to target the HIF-1α gene. Cardiac myocyte apoptosis induced by H/R was assessed by Annexin V-FITC apoptosis assay. HIF-1α, Bnip3 and caspase-3 levels were determined by real-time reverse transcription polymerase chain reaction and western blot for mRNA and protein, respectively. H/R resulted in severe injury in cultured rat cardiomyocytes and it upregulated HIF-1α and proapoptotic Bnip3 mRNA and protein expression. HIF-1α activity inhibited by siRNA significantly decreased (P<0.01) the rate of apoptotic cardiomyocytes induced by 5h of hypoxia followed by 6h of reoxygenation compared with cardiomyocytes without siRNA treatment. Additionally, the expression of Bnip3 and caspase-3 was also markedly reduced. We conclude that HIF-1α is a key regulator of apoptosis of cardiomyocytes induced by H/R. H/R enhances primary neonatal rat cardiomyocyte apoptosis through the activation of HIF-1α and the mechanism might involve Bnip3 and caspase-3. HIF-1α may be a possible therapeutic target to limit myocardial injury after myocardial infarction.

Wang X ，Ma S ，Qi G 《-》