Regulation of glutathione in cardiac myocytes
Regulation of glutathione in cardiac myocytes
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DOI：
10.1016/s0022-2828(03)00230-x
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发表时间：
2003-09-01
影响因子：
5
通讯作者：
Rozanski, GJ
中科院分区：
文献类型：
--
作者：
Li, SM;Li, X;Rozanski, GJ
还原型谷胱甘肽(GSH)是一种重要的多功能三肽，控制氧化还原敏感的细胞过程，但对其在心脏中的调节知之甚少。本研究使用GSH耗竭的药理学模型来研究控制心脏GSH的细胞机制。正常大鼠每日注射谷氨酰半胱氨酸合成酶阻断剂丁硫亚磺胺和谷胱甘肽还原酶抑制剂1，3-二(2-氯乙基)-L-亚硝脲，可引起谷胱甘肽代谢的抑制。在BSO/BCNU处理3d后，用荧光显微镜用一氯二苯甲烷探针测定心肌细胞内[GSH]的含量。BSO/BCNU组大鼠左室肌细胞基础[GSH]水平(2.0+/-0.05amol/um(3)，n=146)比对照组(4.0+/-0.13amol/um(3)，n=116；P<；0.05)低50%。BSO/BCNU大鼠心肌细胞与0.1um胰岛素[GSH]孵育3~4h后(3.6+/-0.29amol/um(3)，n=66)。用放线菌酮处理心肌细胞可阻断胰岛素的这一作用。蛋白酪氨酸磷酸酶抑制剂双过氧钒-1，10-菲咯啉(BPV(Phen)，1um)可引起与胰岛素相似的作用，但这两种药物都不能改变对照组大鼠心肌细胞的[GSH]。此外，PI3K(wortmannin，LY294002)、MEK(PD98059)和p38MAPK(SB203580)的抑制剂可阻断胰岛素和BPV(Phen)上调GSH的作用。这些数据表明，胰岛素信号级联通过PI3-激酶和MAP激酶通路的协调激活来调节心室肌细胞中的[GSH]。这些信号机制可能在控制细胞内氧化还原状态和心肌细胞的正常功能中发挥重要作用。(C)2003爱思唯尔有限公司。保留所有权利。
Reduced glutathione (GSH) is an essential, multifunctional tripepetide that controls redox-sensitive cellular processes, but its regulation in the heart is poorly understood. The present study used a pharmocological model of GSH depletion to examine cellular mechanisms controlling cardiac GSH. Inhibition of GSH metabolism was elicited in normal rats by daily injections of buthionine sulfoximine (BSO), a blocker of gamma-glutamylcysteine synthetase, plus 1,3-bis-(2-chloroethyl)-l-nitrosourea (BCNU), an inhibitor of glutathione reductase. After 3 d of BSO/BCNU treatment, intracellular [GSH] was measured in isolated-ventricular myocytes by fluorescence microscopy using the probe monochlorobimane. Basal [GSH] in left-ventricular myocytes from BSO/BCNU-treated rats (2.0 +/- 0.05 amol/ mum(3), n = 146) was 50% less than control (4.0 +/- 0.13 amol/mum(3), n = 116; P < 0.05). Incubation of myocytes from BSO/BCNU rats with 0.1 muM insulin normalized [GSH] after a delay of 3-4 h (3.6 +/- 0.29 amol/ mum(3), n = 66). This effect of insulin was blocked by pre-treating myocytes with cycloheximide. A protein tyrosine phosphatase inhibitor, bis-peroxovanadium-1, 10-phenanthroline (bpV(phen), 1 muM), elicited a similar effect as insulin, while neither agent altered [GSH] in myocytes from control rats. Moreover, the effect of insulin and bpV(phen) to up-regulate GSH was blocked by inhibitors of PI 3-kinase (wortmannin, LY294002), MEK (PD98059) and p38 MAP kinases (SB203580). These data suggest that the insulin-signaling cascade regulates [GSH] in ventricular myocytes by a coordinated activation of PI 3-kinase and MAP kinase pathways. These signaling mechanisms may play essential roles in controlling intracellular redox state and normal function of cardiac myocytes. (C) 2003 Elsevier Ltd. All rights reserved.