Wei T, Chen C, Hou J, Zhao B, Xin W, Mori A
Institute of Biophysics, Academia Sinica, Chaoyang District, Beijing, China.
Toxicology. 1999 Jun 15;134(2-3):117-26. doi: 10.1016/s0300-483x(99)00030-x.
In this study we investigated the effects of nitric oxide (NO) on cultured cerebellar granule cells. Exposure to NO donors, S-nitrosoglutathione (GSNO; 250 microM) or sodium nitroprusside (SNP; 500 microM), triggered apoptosis in immature cultures of cerebellar granule cells, which was characterized by chromatin condensation, nuclei fragmentation, and DNA laddering. Exposure of cerebellar granule cells to NO donors led to a decrease in the mitochondrial transmembrane potential and intracellular ATP content, which suggested that NO treatment caused mitochondrial dysfunction. NO treatment also induced oxidative stress in cerebellar granule cells as measured by thiobarbituric acid (TBA) assay. Pretreating cells with L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H -1-benzopyran-6-yl-hydrogen phosphate] potassium salt (EPC-K1), a novel antioxidant, attenuated NO-induced mitochondrial dysfunction and oxidative stress to some extent, and prevented the cells from apoptosis. The results of the present investigation suggest that a superoxide/peroxynitrite-mediated oxidative stress may be an important pathway leading to NO-associated neuronal damage. Pretreating cells with the antioxidant EPC-K1 attenuated NO-induced neurotoxicity by scavenging superoxide/peroxynitrite and/or its breakdown products.
在本研究中，我们调查了一氧化氮（NO）对培养的小脑颗粒细胞的影响。将小脑颗粒细胞暴露于NO供体，即S-亚硝基谷胱甘肽（GSNO；250微摩尔）或硝普钠（SNP；500微摩尔），会引发未成熟小脑颗粒细胞培养物中的细胞凋亡，其特征为染色质凝聚、细胞核碎片化和DNA梯状条带形成。将小脑颗粒细胞暴露于NO供体导致线粒体跨膜电位和细胞内ATP含量降低，这表明NO处理导致了线粒体功能障碍。通过硫代巴比妥酸（TBA）测定法测量发现，NO处理还诱导了小脑颗粒细胞中的氧化应激。用新型抗氧化剂L-抗坏血酸2-[3,4-二氢-2,5,7,8-四甲基-2-(4,8,12-三甲基十三烷基)-2H-1-苯并吡喃-6-基-氢磷酸]钾盐（EPC-K1）预处理细胞，在一定程度上减轻了NO诱导的线粒体功能障碍和氧化应激，并防止细胞凋亡。本研究结果表明，超氧化物/过氧亚硝酸盐介导的氧化应激可能是导致NO相关神经元损伤的重要途径。用抗氧化剂EPC-K1预处理细胞，通过清除超氧化物/过氧亚硝酸盐和/或其分解产物，减轻了NO诱导的神经毒性。
