Exogenous H2 S contributes to recovery of ischemic post-conditioning-induced cardioprotection in the aging rat hearts and cardiomyocytes / 中国病理生理杂志

ABSTRACT

AIM: Ischemic post-conditioning ( PC) plays an important role in cardioprotection from ischemia /reperfusion ( I/R) injury in the young heart but not in the aging hearts .The physiological and pathological roles of hydrogen sulfide ( H2 S) in the regulation of cardio-vascular functions have been recognized .Whether H2 S is involved in the recovery of PC-induced cardioprotection in the aging hearts is unclear.METHOD:The male Wistar young rats (3-month-old), the aging rats (24-month-old), primary cultured cardiomyocytes and the aging cardiomyocytes induced by D-galactose suffered from I/R (or H/R) and PC.RESULTS:I/R (or H/R) decreased H2S production rate and cystathionine γ-lyase (CSE) expression, aggravated cardiomyocyte damage , apoptosis, myocardial infarct size and oxidative stress, reduced cardiac function, increased the levels of Bcl-2, cleaved caspase-3 and caspase-9 mRNA and proteins, promo-ted the release of cytochrome c and mPTP opening, down-regulated the phosphorylation of ERK 1/2, PI3K, Akt and GSK-3βand mito-chondrial membrane potential , up-regulated the phosphorylation of IκBα, NF-κB, JNK2 and STAT3, and inhibited PKC-ε transloca-tion and mitochondrial ATP-sensitive K channels (mitoKATP) in isolated young and aging hearts as well as normal and aging cardiomyo-cytes.PC suppressed myocardial I/R injury in the young heart but not in the aging hearts .Supply of NaHS not only increased PC-in-duced cardioprotection in the young hearts and cardiomyocytes , but also attenuated I/R injury and significantly recovered the cardiopro-tective role of PC in the aging hearts and cardiomyocytes .CONCLUSION:The exogenous H 2 S restores PC-induced cardioprotection through inhibiting oxidative stress via the down-regulation of NF-κB and JAK2-STAT3 pathways and mPTP opening by the up-regulation of ERK1/2-GSK-3β, PI3K-Akt-GSK-3βand PKC-ε-mitoKATP pathways in the aging hearts and cardiomyocytes .These findings provide a novel potential target for the treatment of aging ischemic cardiomyopathy .