Protection from oxidant injury by sodium-dependent GSH uptake in retinal Muller cells
Protection from oxidant injury by sodium-dependent GSH uptake in retinal Muller cells
复制标题
DOI：
10.1006/exer.1998.0639
复制
发表时间：
1999-05-01
影响因子：
3.4
通讯作者：
Kaplowitz, N
中科院分区：
文献类型：
--
作者：
Kannan, R;Bao, YZ;Kaplowitz, N
已知谷胱甘肽（GSH）在调节细胞氧化损伤中起重要作用。本研究旨在研究外源性谷胱甘肽对视网膜Muller细胞系氧化损伤的影响，并表征谷胱甘肽在这些细胞中的转运。用不同浓度的t-丁基过氧化氢（t-BHP）培养大鼠Muller细胞（rMC-1），诱导氧化应激，加入谷胱甘肽后测定细胞活力。在其他研究中，通过在含Na+和不含Na+的缓冲液中培养含有S-35-GSH的细胞，研究了GSH摄取动力学和Na+依赖性。在NaCl缓冲液中，用浓度为0.05 ~ 10 mM的谷胱甘肽研究谷胱甘肽的吸收。在钠存在的情况下，胞外谷胱甘肽对t- bhp诱导的rMC-1细胞氧化损伤提供保护；相反，谷胱甘肽的氨基酸前体对细胞活力没有任何影响。GSH被rMC-1细胞以浓度和钠依赖的方式摄取。动力学研究显示高亲和力（K-m接近0.31 mM）和低亲和力K-m（接近4.2 mM）成分。此外，谷胱甘肽耗竭对谷胱甘肽摄取速率没有显著影响。结果表明，生理浓度的谷胱甘肽能保护Muller细胞免受氧化损伤。Muller细胞中存在Na+依赖性和Na+非依赖性GSH转运系统，Na+依赖性GSH转运体可能参与GSH的保护作用。(C) 1999学术出版社。
Glutathione (GSH) is known to play an important role in regulating oxidative damage to cells. The present study was initiated to examine the effect of exogenous GSH on oxidative injury in a retinal Muller cell line and to characterize GSH transport in these cells. Rat Muller cells (rMC-1) were incubated with varying concentrations of t-butylhydroperoxide (t-BHP) to induce oxidative stress, and cell viability was measured after addition of GSH. In other studies, kinetics of GSH uptake and Na+-dependency were examined by incubating cells with S-35-GSH in Na+-containing and Na+-free buffers. GSH uptake was studied with GSH at concentrations varying from 0.05-10 mM in NaCl buffer. In the presence of sodium, extracellular GSH provided protection against t-BHP-induced oxidant injury to rMC-1 cells; in contrast, the amino acid precursors of GSH did not have any effect on cell viability. GSH was taken up by rMC-1 cells in a concentration- and sodium-dependent manner. Kinetic studies revealed both a high affinity (K-m similar to 0.31 mM) and low affinity K-m (similar to 4.2 mM) component. Furthermore, GSH depletion had no significant effect on the rate of GSH uptake. The results show that physiological concentrations of GSH can protect Muller cells from oxidative injury. Both Na+-dependent and Na+-independent transport systems for GSH exist in Muller cells, and the Na+-dependent GSH transporter may be involved in the protective role of GSH. (C) 1999 Academic Press.