HYDROGEN PEROXIDE-INDUCED OXIDATIVE STRESS TO THE MAMMALIAN HEART-MUSCLE CELL (CARDIOMYOCYTE) - LETHAL PEROXIDATIVE MEMBRANE INJURY
HYDROGEN PEROXIDE-INDUCED OXIDATIVE STRESS TO THE MAMMALIAN HEART-MUSCLE CELL (CARDIOMYOCYTE) - LETHAL PEROXIDATIVE MEMBRANE INJURY
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DOI：
10.1002/jcp.1041490302
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发表时间：
1991-12-01
影响因子：
5.6
通讯作者：
SHARIF, HM
中科院分区：
文献类型：
--
作者：
JANERO, DR;HRENIUK, D;SHARIF, HM
过氧化氢（H2O2）诱导的氧化应激可能导致心脏缺血再灌注损伤的发病机制。为了直接研究H2O2对心肌的损伤潜力，建立了H2O2诱导的心肌氧化应激的细胞模型。该模型采用完整的、跳动的新生大鼠心肌细胞的原代单层培养物和在限定的、无补充剂的培养基中的离散浓度的试剂H2O2。受到 H2O2 攻击的心肌细胞很容易代谢它，因此培养物中 H2O2 的含量随着时间的推移而减少，但并未耗尽。随后的 H2O2 诱导的氧化应激导致致命的肌膜破坏（通过乳酸脱氢酶释放来测量），而过氧化氢酶可以保留心肌细胞的完整性。在氧化应激过程中，会出现一系列细胞紊乱，包括膜磷脂过氧化、硫醇氧化、主要断链膜抗过氧化剂（α-生育酚）的消耗以及 ATP 损失。 H2O2 诱导的氧化应激并未导致心肌细胞膜的蛋白质或磷脂含量发生净变化，但 H2O2 导致这些膜成分的周转增加。 H2O2 诱导的氧化应激过程中致命性心肌细胞损伤的发生并不需要 H2O2 本身的存在；心肌细胞短暂“脉冲”接触 H2O2 足以激发导致细胞破坏的致病机制。心肌细胞的破坏取决于氧化还原活性铁的细胞内来源以及内化的 H2O2 依赖铁的转化为能够引发脂质过氧化的产物（例如羟基自由基），因为铁螯合剂和羟基自由基清除剂具有细胞保护作用。心肌细胞膜蛋白和磷脂的加速周转受到抗过氧化剂的抑制，表明周转反映了氧化膜成分的分子修复。同样，α-生育酚的消耗和细胞硫醇的氧化似乎是过氧化的副现象。抗过氧化剂干预协调地消除了 H2O2 诱导的脂质过氧化和肌膜破坏，这表明肌膜过氧化与响应 H2O2 诱导的氧化应激的心肌细胞完整性的致命损害之间存在密切的致病关系。 H2O2 诱导的氧化应激过程中心肌细胞的破坏，还确定了 H2O2 细胞毒性的非过氧化途径，该途径在完全不存在心肌细胞膜过氧化的情况下表达。H2O2 诱导的心肌细胞损伤的后一种模式涉及 ATP 损失，因此一方面膜过氧化和心肌细胞破坏，另一方面细胞失能可以完全分离。 “触发”肌膜不可逆过氧化破坏的心肌细胞坏死矢量信号对于缺血后心脏氧化损伤的潜在机制具有影响。
Oxidative stress induced by hydrogen peroxide (H2O2) may contribute to the pathogenesis of ischemic-reperfusion injury in the heart. For the purpose of investigating directly the injury potential of H2O2 on heart muscle, a cellular model of H2O2-induced myocardial oxidative stress was developed. This model employed primary monolayer cultures of intact, beating neonatal-rat cardiomyocytes and discrete concentrations of reagent H2O2 in defined, supplement-free culture medium. Cardiomyocytes challenged with H2O2 readily metabolized it such that the culture content of H2O2 diminished over time, but was not depleted. The consequent H2O2-induced oxidative stress caused lethal sarcolemmal disruption (as measured by lactate dehydrogenase release), and cardiomyocyte integrity could be preserved by catalase. During oxidative stress, a spectrum of cellular derangements developed, including membrane phospholipid peroxidation, thiol oxidation, consumption of the major chain-breaking membrane antiperoxidant (alpha-tocopherol), and ATP loss. No net change in the protein or phospholipid contents of cardiomyocyte membranes accompanied H2O2-induced oxidative stress, but an increased turnover of these membrane constituents occurred in response to H2O2. Development of lethal cardiomyocyte injury during H2O2-induced oxidative stress did not require the presence of H2O2 itself; a brief "pulse" exposure of the cardiomyocytes to H2O2 was sufficient to incite the pathogenic mechanism leading to cell disruption. Cardiomyocyte disruption was dependent upon an intracellular source of redox-active iron and the iron-dependent transformation of internalized H2O2 into products (e.g., the hydroxyl radical) capable of initiating lipid peroxidation, since iron chelators and hydroxyl-radical scavengers were cytoprotective. The accelerated turnover of cardiomyocyte-membrane protein and phospholipid was inhibited by antiperoxidants, suggesting that the turnover reflected molecular repair of oxidized membrane constituents. Likewise, the consumption of (alpha-tocopherol and the oxidation of cellular thiols appeared to be epiphenomena of peroxidation. Antiperoxidant interventions coordinately abolished both H2O2-induced lipid peroxidation and sarcolemmal disruption, demonstrating that an intimate pathogenic relationship exists between sarcolemmal peroxidation and lethal compromise of cardiomyocyte integrity in response to H2O2-induced oxidative stress. Although sarcolemmal peroxidation was causally related to cardiomyocyte disruption during H2O2-induced oxidative stress, a nonperoxidative route of H2O2 cytotoxicity was also identified, which was expressed in the complete absence of cardiomyocyte-membrane peroxidation. The latter mode of H2O2-induced cardiomyocyte injury involved ATP loss such that membrane peroxidation and cardiomyocyte disruption on the one hand and cellular de-energization on the other could be completely dissociated. The cellular pathophysiology of H2O2 as a vectorial signal for cardiomyocyte necrosis that "triggers" irreversible peroxidative disruption of the sarcolemma has implications regarding potential mechanisms of oxidative injury in the postischemic heart.