叠氮钠损伤的神经元内硫氧还蛋白mRNA水平的变化

CHANGES OF THIOREDOXIN mRNA LEVEL IN NEURONS INSULTED BY SODIUM AZIDE

氧化应激与许多神经退变病有关,而线粒体损伤是氧化应激加剧的重要原因。本文通过细胞活性检测(MTT法)、形态学观察,分析NaN_3对原代培养神经元的损伤作用,并通过RT-PCR半定量检测NaN_3损伤后神经元内疏氧还蛋白(Thioredoxin,Trx)mRNA水平的改变,以阐明这一重要的氧还调节蛋白在神经元损伤过程中的作用。实验表明NaN_3以浓度和时间依赖方式损伤神经元,降低Trx表达水平。提示:神经元内呼吸链受损引起Trx表达减少,从而减弱神经元内氧还调节功能,最终引起神经元损伤、死亡。

Oxidative stress has been considered to be associated with many neurodegenerative diseases, while mitochondria! damage is one of the important reasons that aggravate oxidative stress. Sodium azide (NaN3) is a specific inhibitor of mitochondrial cytochrome c oxidase (COX) , which can be used to mimic neu-ronal damage induced by mitochondrial deficiency. In this experiment, the neurotoxic effects of NaN3 on cultured primary neurons were detected by means of cell viability measurement (MTT assay) and morphological observation, and an in vitro model of neuronal injury induced by NaN3 were established. Further the changes of thioredoxin mRNA level in cultured neurons insulted by NaN3 were analyzed by semiquantitative RT-PCR in order to explore the role of Trx, an important redox regulatory protein, in the process of neuronal injury. It was found that cultured neurons could be damaged by NaN3 in a dose- and time-dependent manner and the expression of Trx decreased during certain dose (0 - 32mmol/L) and time (0 - 4hr) of NaN3 treatment. The above data suggest that decreased the expression of Trx may be associated with oxidative stress induced by neuronal respiratory chain injury, which could impair neuronal protective mechanism.