H2S cytotoxicity mechanism involves reactive oxygen species formation and mitochondrial depolarisation
H2S cytotoxicity mechanism involves reactive oxygen species formation and mitochondrial depolarisation
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DOI：
10.1016/j.tox.2004.05.020
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发表时间：
2004-10-15
期刊：
影响因子：
4.5
通讯作者：
O'Brien, PJ
中科院分区：
文献类型：
--
作者：
Eghbal, MA;Pennefather, PS;O'Brien, PJ
一些活性氧(ROS)清除剂对硫化氢(H_2S)诱导的肝细胞死亡有保护作用。过氧化氢清除α-酮戊二酸和丙酮酸，这两种物质也是能量底物代谢物。对H_2S毒性的保护作用强于乳酸，乳酸只是能量底物的代谢物。所有这些结果表明，H_2S毒性依赖于ROS的产生。我们用荧光二氯荧光素方法直接测量了肝细胞中ROS的形成。H_2S诱导的ROS生成呈剂量依赖关系，丙酮酸抑制这种ROS的生成。无毒浓度的H_2S可增强葡萄糖/葡萄糖氧化酶产生的H_2O_2的细胞毒性，这种作用可被细胞色素P450抑制剂抑制。此外，细胞色素P450抑制剂西咪替丁和苯并咪唑可减少H_2S诱导的肝细胞ROS生成。这些结果表明，细胞色素P450依赖的H_2S代谢是诱导ROS产生的原因。用罗丹明123荧光法测定，线粒体去极化作用先于H_2S诱导的细胞毒作用。锌、蛋氨酸和丙酮酸可阻止硫化氢诱导的线粒体去极化，从而减少硫化氢诱导的细胞死亡。硫化氢中毒的治疗可能受益于旨在将ROS引起的损害降至最低并减少线粒体损害的干预措施。(C)2004爱思唯尔爱尔兰有限公司。保留所有权利。
A number of scavengers of reactive oxygen species (ROS) were found to be protective against cell death induced by hydrogen sulfide (H2S) in isolated hepatocytes. The H2O2 scavengers alpha-ketoglutarate and pyruvate, which also act as energy substrate metabolites. were more protective against H2S toxicity than lactate which is only an energy substrate metabolite. All of these results suggest that H2S toxicity is dependent on ROS production. We measured ROS formation directly in hepatocytes using the fluorogenic dichlorofluorescin method. H2S-induced ROS formation was dose dependent and pyruvate inhibited this ROS production. Non-toxic concentrations of H2S enhanced the cytotoxicity of H2O2 generated by glucose/glucose oxidase, which was inhibited by CYP450 inibitors. Furthermore, hepatocyte ROS formation induced by H2S was decreased by CYP450 inhibitors cimetidine and benzylimidazole. These results suggest that CYP450-dependant metabolism of H2S is responsible for inducing ROS production. H2S-induced cytotoxicity was preceded by mitochondrial depolarization as measured by rhodamine 123 fluorescence. Mitochondrial depolarization induced by H2S was prevented by zinc, methionine and pyruvate all of which decreased H2S-induced cell death. Treatment of H2S poisoning may benefit from interventions aimed at minimizing ROS-induced damage and reducing mitochondrial damage. (C) 2004 Elsevier Ireland Ltd. All rights reserved.