Levrand Sandra, Vannay-Bouchiche Christine, Pesse Benoît, Pacher Pal, Feihl François, Waeber Bernard, Liaudet Lucas
Department of Intensive Care Medicine, BH 10-982, University Hospital, 1011 Lausanne, Switzerland.
Free Radic Biol Med. 2006 Sep 15;41(6):886-95. doi: 10.1016/j.freeradbiomed.2006.04.034. Epub 2006 Jun 7.
Recent evidence indicates that peroxynitrite represents a major cytotoxic effector in heart diseases, but its mechanisms of action are still not known exactly. Notably, the ability of peroxynitrite to trigger cardiomyocyte apoptosis, a crucial mode of cell death in many cardiac conditions, remains poorly defined. We evaluated apoptotic and necrotic cell death in cultured H9C2 cardiomyocytes, following a brief (20 min) exposure to peroxynitrite (50-500 microM). Peroxynitrite-dependent myocardial toxicity was then investigated in a rat model of myocardial ischemia-reperfusion (MIR), where the effects of peroxynitrite were blocked by the superoxide dismutase mimetics and peroxynitrite scavenger Mn(III)-tetrakis(4-benzoic acid) porphyrin (MnTBAP). In vitro, peroxynitrite killed cardiomyocytes mostly through apoptosis (DNA fragmentation, apoptotic nuclear alterations, caspase-3 activation, and PARP cleavage), but not necrosis (propidium iodide staining and LDH release). In vivo, MIR triggered myocardial oxidative stress (malondialdehyde generation), nitrotyrosine formation, neutrophil accumulation, and the cleavage of caspase-3 and PARP, indicating ongoing myocardial apoptosis. MnTBAP suppressed these alterations, allowing a considerable reduction of myocardial injury. Thus, peroxynitrite triggers apoptosis in cardiomyocytes in vitro and in the myocardium in vivo, through a pathway involving caspase-3 activation and the cleavage of PARP. These results provide important novel information on the mechanisms of myocardial toxicity of peroxynitrite.
最近的证据表明，过氧亚硝酸根是心脏病中的一种主要细胞毒性效应物，但其作用机制仍不完全清楚。值得注意的是，过氧亚硝酸根引发心肌细胞凋亡的能力，这在许多心脏疾病中是一种关键的细胞死亡模式，仍未得到很好的界定。我们评估了培养的H9C2心肌细胞在短暂（20分钟）暴露于过氧亚硝酸根（50 - 500微摩尔）后的凋亡和坏死性细胞死亡。然后在心肌缺血再灌注（MIR）大鼠模型中研究了过氧亚硝酸根依赖性心肌毒性，其中过氧亚硝酸根的作用被超氧化物歧化酶模拟物和过氧亚硝酸根清除剂锰（III）-四（4-苯甲酸）卟啉（MnTBAP）所阻断。在体外，过氧亚硝酸根主要通过凋亡（DNA片段化、凋亡性核改变、半胱天冬酶-3激活和聚（ADP-核糖）聚合酶裂解）而非坏死（碘化丙啶染色和乳酸脱氢酶释放）杀死心肌细胞。在体内，MIR引发心肌氧化应激（丙二醛生成）、硝基酪氨酸形成、中性粒细胞积聚以及半胱天冬酶-3和聚（ADP-核糖）聚合酶的裂解，表明心肌持续凋亡。MnTBAP抑制了这些改变，使心肌损伤显著减轻。因此，过氧亚硝酸根通过涉及半胱天冬酶-3激活和聚（ADP-核糖）聚合酶裂解的途径在体外心肌细胞和体内心肌中引发凋亡。这些结果为过氧亚硝酸根心肌毒性机制提供了重要的新信息。
