【摘要】 观察硫酸锂对磷酸肌醇 3位羟基激酶LY2 940 0 2 (50 μmol· L-1)诱导体外培养的大鼠小脑颗粒神经元凋亡的拮抗作用 .结果显示 ,硫酸锂能明显阻断 LY 2 940 0 2诱导的神经元死亡 ,促进神经元存活 (MTT还原法 ) ,IC50 为 1 .2 5- 2 .5mmol· L-1.硫酸锂 (5.0 mmol· L-1)和 LY2 940 0 2同时处理神经元 ,LY2 940 0 2诱导的 DNA片段化(DNA琼脂糖凝胶电泳法 )和核固缩 (Hoechst332 58核染色法 )不再发生 .说明锂离子可对抗LY 2 940 0 2诱导的神经元凋亡 .采用间接荧光免疫法观察磷酸化 c- Jun蛋白免疫阳性神经元数目 ,结果显示 ,LY2 940 0 2组在 1 2 h可见大量磷酸化c- Jun免疫阳性神经元 ,2 4 h荧光更强 ;而硫酸锂(5.0 mmol·L-1)加 LY2 940 0 2组在各时间点未见磷酸化 c- Jun蛋白免疫阳性细胞 .提示锂离子抗LY2 940 0 2诱导的神经元凋亡的作用通过抑制c- Jun蛋白磷酸化过程起作用 ,其确切机理有待进一步探讨 .更多还原

【Abstract】 Using phase-contrast microscopy, Hoechst33258 staining and DNA agarose gel electrophoresis, and MTT reduction assay, the protective effect of lithium against the neuronal apoptosis induced by LY 294002 (2-[4-morpholinyl]-8-phenyl-1[4H]-benzopyran-4-one, 50 μmol·L -1), a specific inhibitor of phosphatidylinositol-3-kinase,on cultured cerebellar granule neurons was tested. Results indicated that Li 2SO 4 prevented apoptosis in a concentration-dependent manner with EC 50 1.25-2.5 mmol·L -1. The neurons were exposed to LY 294002 in the absence or presence of Li 2SO 4(5.0 mmol·L -1) for 24 h. The effects of diminished neuronal body, chromatin concentration, nuclear pyknosis and DNA fragmentation induced by LY 294002 were almost blocked by Li 2SO 4, which indicated that lithium blocked the LY 294002-induced neuronal apoptosis. Using indirect immunofluorescence assay at different time after the neurons were exposed to corresponding conditions, the number of phosphoryl-c-Jun positive neurons was increased robustly after neurons were treated with LY 294002 for 12 h. The fluorescence became stronger at 24 h. Few phosphoryl-c-Jun positive neurons were found when exposed to LY 294002 and Li 2SO 4(5.0 mmol·L -1) simultaneously at any time-point. These results indicated that lithium might prevent apoptosis induced by LY 294002 through inhibiting the phosphorylation of c-Jun. The exact mechanism needs more experiments to be elucidated.更多还原