Nicole A, Santiard-Baron D, Ceballos-Picot I
CNRS URA 1335, Hôpital Necker-Enfants Malades, Paris, France.
Biomed Pharmacother. 1998;52(9):349-55. doi: 10.1016/S0753-3322(99)80001-8.
Recent evidence has focused attention on the role of oxidative stress in various acute and chronic neurodegenerative diseases. Particularly, a decrease in the level of the powerful antioxidant glutathione (GSH) and death of dopaminergic neurons in substantia nigra are prominent features in Parkinson's disease. The mode of neuronal death is uncertain; however, apoptosis has been hypothesized to be mediated through the induction of free radicals via oxidative pathways. An approach to determine the role of GSH depletion in neurodegeneration and apoptosis was to create a selective modulation of this antioxidant by metabolic manipulations in a clonal cell line of neuronal origin (mouse neuroblastoma NS20Y). Intracellular GSH levels was lowered by inhibiting its biosynthesis with L-buthionine-(S,R)-sulfoximine (BSO), a specific inhibitor of gamma-glutamylcysteine synthetase. This treatment led to a GSH depletion of 50% after 1 h and 98% after 24 h. A direct cause/effect relationship between GSH depletion and apoptosis was evidenced in this neuronal cell type. GSH depletion induced the death of NS20Y and promoted nuclear alterations of apoptosis as demonstrated by the in situ staining of DNA fragmentation after 5 days of BSO treatment (by terminal-deoxynucleotide transferase-mediated dUTP-nick end labeling), and the appearance of DNA laddering on agarose gel. These results suggested that redox desequilibrium induced by GSH depletion may serve as a general trigger for apoptosis in neuronal cells, and are consistent with the hypothesis that GSH depletion contribute to neuronal death in Parkinson's disease.
最近的证据使人们将注意力集中在氧化应激在各种急性和慢性神经退行性疾病中的作用上。特别是，强大的抗氧化剂谷胱甘肽（GSH）水平降低以及黑质中多巴胺能神经元死亡是帕金森病的突出特征。神经元死亡的方式尚不确定；然而，据推测细胞凋亡是通过氧化途径诱导自由基介导的。一种确定GSH耗竭在神经退行性变和细胞凋亡中作用的方法是通过对神经元来源的克隆细胞系（小鼠神经母细胞瘤NS20Y）进行代谢操作来选择性调节这种抗氧化剂。用γ-谷氨酰半胱氨酸合成酶的特异性抑制剂L-丁硫氨酸-（S，R）-亚砜亚胺（BSO）抑制其生物合成，可降低细胞内GSH水平。这种处理在1小时后导致GSH耗竭50%，24小时后耗竭98%。在这种神经元细胞类型中证明了GSH耗竭与细胞凋亡之间存在直接的因果关系。GSH耗竭诱导了NS20Y细胞死亡并促进了凋亡的核改变，如BSO处理5天后DNA片段化的原位染色（通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记）以及琼脂糖凝胶上出现DNA梯带所示。这些结果表明，GSH耗竭引起的氧化还原失衡可能是神经元细胞凋亡的一般触发因素，这与GSH耗竭导致帕金森病中神经元死亡的假说一致。
