Webster Keith A
Department of Molecular & Cellular Pharmacology, University of Miami Medical Center, FL 33101, USA.
Future Cardiol. 2012 Nov;8(6):863-84. doi: 10.2217/fca.12.58.
Excess generation of reactive oxygen species (ROS) and cytosolic calcium accumulation play major roles in the initiation of programmed cell death during acute myocardial infarction. Cell death may include necrosis, apoptosis and autophagy, and combinations thereof. During ischemia, calcium handling between the sarcoplasmic reticulum and myofilament is disrupted and calcium is diverted to the mitochondria causing swelling. Reperfusion, while essential for survival, reactivates energy transduction and contractility and causes the release of ROS and additional ionic imbalance. During acute ischemia-reperfusion, the principal death pathways are programmed necrosis and apoptosis through the intrinsic pathway, initiated by the opening of the mitochondrial permeability transition pore and outer mitochondrial membrane permeabilization, respectively. Despite intense investigation, the mechanisms of action and modes of regulation of mitochondrial membrane permeabilization are incompletely understood. Extrinsic apoptosis, necroptosis and autophagy may also contribute to ischemia-reperfusion injury. In this review, the roles of dysregulated calcium and ROS and the contributions of Bcl-2 proteins, as well as mitochondrial morphology in promoting mitochondrial membrane permeability change and the ensuing cell death during myocardial infarction are discussed.
活性氧(ROS)的过度生成和胞质钙积累在急性心肌梗死期间程序性细胞死亡的启动中起主要作用。细胞死亡可能包括坏死、凋亡和自噬,以及它们的组合。在缺血期间,肌浆网和肌丝之间的钙处理被破坏,钙被转移到线粒体导致肿胀。再灌注虽然对存活至关重要,但会重新激活能量转导和收缩力,并导致ROS释放和额外的离子失衡。在急性缺血再灌注期间,主要的死亡途径是通过内在途径的程序性坏死和凋亡,分别由线粒体通透性转换孔的开放和线粒体外膜通透性增加引发。尽管进行了深入研究,但线粒体膜通透性的作用机制和调节模式仍未完全了解。外在凋亡、坏死性凋亡和自噬也可能导致缺血再灌注损伤。在这篇综述中,讨论了钙和ROS失调的作用、Bcl-2蛋白的贡献,以及线粒体形态在促进心肌梗死期间线粒体膜通透性变化和随之而来的细胞死亡中的作用。