Tumor necrosis factor-alpha confers resistance to hypoxic injury in the adult mammalian cardiac myocyte

Article

关键词: MANGANOUS SUPEROXIDE-DISMUTASE;    II-INDUCED HYPERTROPHY;    HEAT-SHOCK PROTEINS;    ANGIOTENSIN-II;    GROWTH-FACTORS;    MYOCARDIAL-INFARCTION;    RAT CARDIOMYOCYTES;    FACTOR CHALLENGES;    FACTOR RECEPTORS;    GENE-EXPRESSION;   

DOI  :  10.1161/01.CIR.97.14.1392

来源: SCIE

【 摘 要 】

Background-Previous studies in isolated cardiac myocytes have shown that tumor necrosis factor (TNF)-alpha: provokes increased expression of 27- and 70-kD stress proteins as well as manganese superoxide dismutase, suggesting that TNF-alpha might play a role in mediating stress responses in the heart. Methods and Results-To determine whether TNF-alpha stimulation would protect isolated cardiac myocytes against environmental stress, myocyte cultures were pretreated with TNF-alpha for 12 hours and then subjected to continuous hypoxic injury (O-2 content, 3 to 5 ppm) for 12 hours, followed by reoxygenation. Cell injury was assessed in terms of lactic dehydrogenase (LDH) release, Ca-45(2+) uptake, and MTT metabolism. Pretreatment with TNF-alpha concentrations greater than or equal to 50 U/mL significantly attenuated LDH release by hypoxic cells compared with diluent-treated hypoxic cells. Similar findings were observed with respect to Ca-45(2+) uptake and MTT metabolism in TNF-alpha-pretreated cells that were subjected to prolonged hypoxia. To determine the mechanism for the TNF-alpha-induced protective effect, the cells were pretreated with heat shock protein (HSP) 72 antisense oligonucleotides. These studies showed that the protective effect of TNF-alpha was not inhibited by antisense oligonucleotides, despite use of a concentration of antisense that was sufficient to attenuate the TNF-alpha-induced increase in HSP 72 expression. Subsequent studies using mutated TNF ligands showed that activation of both types 1 and 2 TNF receptors was sufficient to confer a protective response in isolated cardiac myocytes through an as yet unknown pathway(s). Conclusions-Taken together, the above observations demonstrate that TNF-alpha pretreatment confers resistance to hypoxic stress in the adult cardiac myocyte through a novel mechanism that appears to be different from but not necessarily exclusive of the protective response conferred by HSP 72 expression.

【 授权许可】

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