Induction ofHSP 32gene in hypoxic cardiomyocytes is attenuated by treatment withN-acetyl- l -cysteine

作者：Darrell R. Borger, David A. Essig · 发表于：American Journal of Physiology-Heart and Circulatory Physiology · 年份：1998 · DOI：10.1152/ajpheart.1998.274.3.h965 · 被引用次数：46 · 研究领域：Heme Oxygenase-1 and Carbon Monoxide、Cardiac Arrest and Resuscitation、Thermal Regulation in Medicine

Increased synthesis of stress proteins may enhance myocardial viability during periods of low oxygen delivery. Our purpose was to determine if the oxidative stress protein heme oxygenase-1 [heat stress protein 32 (HSP 32)] was induced in hypoxic cardiomyocytes and whether this induction might be mediated by a redox-sensitive mechanism. Primary rat neonatal cardiomyocytes, cultured to express a tissuelike phenotype, responded to 12 h of hypoxia (< 0.5% ambient oxygen) with an approximately fivefold (range 3- to 7.5-fold; P < 0.05) increase in HSP 32 mRNA and a threefold (P < 0.05) increase in HSP 32 protein content. Exposure to 80 microM H2O2 for 3 h increased HSP 32 mRNA content to a similar extent. Expression of heme oxygenase-2 mRNA was unaffected by H2O2 or hypoxic treatments. Inclusion of 20 mM N-acetyl-L-cysteine in the medium during hypoxia reduced the increase in HSP 32 mRNA and protein expression by 25.50% compared with hypoxia alone. The data suggest that induction of HSP 32 protein may lead to an improved antioxidant defense in cardiomyocytes during hypoxia and that a redox-sensitive pathway mediates at least a portion of the hypoxic induction of the HSP 32 gene.