L-茶氨酸减轻叠氮钠诱导的人神经母细胞瘤SH-SY5Y细胞线粒体损伤

L-theanine attenuates sodium-azide-induced injury on mitochondrial in SH-SY5Y cells

目的研究L-茶氨酸对叠氮钠（NaN，）诱导的人神经母细胞瘤（SH-SYSY）细胞线粒体损伤的影响其机制。方法将不同浓度的L-茶氨酸及NaN，与SH-SYSY细胞系共同孵育，用M1Tr法测定细胞存活力，以JC-1测定法和激光共聚焦显微镜来观察线粒体膜电位，Westernblot法检测细胞内caspase-3、caspase-9和细胞色素C蛋白表达水平。结果1）随着NaN，浓度的增高，细胞活性逐步降低，提前2h给予茶氨酸（0．25、0．50和1．00mmol／L）能明显降低NaN，（0．25mmol／L）孵育24h对细胞的毒性并逆转线粒体跨膜电位的下降（P〈0．05）；2）茶氨酸在0．25-1．00mmol／L浓度范围内能显著逆转NaN，诱导的SH-SYSY细胞内caspase-3、caspase-9和细胞色素c蛋白表达水平的升高（P〈0．05）。结论茶氨酸可以通过稳定SH-SYSY细胞线粒体膜电位，减轻细胞线粒体的损伤。

Objective To investigate the effects and its mechanism of L-theanine on mitochondrial injury induced by sodium azide in SH-SY5Y cells. Methods The SH-SY5Y cells were exposed to different concentrations of L-theanine and the sodium azide, the cell viability was measured by the MTT method, the mitochondrial membrane potential was detected by the JC-1 method and the Scanning Confocal Microscopy. The protein level of intracellular caspase-3, caspase-9 and cytochrome c was detected by the Western Blotting Method. Results 1 ） With the increase of the con- centration of sodium azide, the cell activity decreases gradually. After pretreatment by L-theanine （0. 25,0. 50, 1.00 mmol/L） for 2 hours,it significantly reduced cell toxicity and reversed decline in the mitochondrial membrane potential induced by the sodium azide （0. 25 mmol/L） for 24 hours（P 〈0. 05）. 2） L-theanine（0. 25 - 1.0 mmol/L） significantly reversed the increasing of the protein expression level of the easpase-3, caspase-9 and cytoehrome c in- duced by the sodium azide in SH-SY5Y cell（P 〈0. 05）. Conclusions L-Theanine can stabilize mitochondrial mem- brane potential of the SH-SY5Y cell and thus reduce the mitoehondrial damage.