镧对大鼠原代星形胶质细胞Bax和Bcl-2表达的影响

Effects of Lanthanum on the expression of Bax and Bcl-2 in primary cultured astrocytes of rats

目的研究不同剂量氯化镧(lanthanum chloride,LaCl3)对大鼠原代星形胶质细胞凋亡以及促凋亡基因Bax、抑凋亡基因Bcl-2表达的影响。方法原代培养的大鼠大脑皮质星形胶质细胞经0、0.125、0.25、0.5和1.0 mmol/LLaCl3处理12和24 h后,采用四甲基偶氮唑盐(MTT)法检测细胞存活率,采用流式细胞仪检测细胞凋亡率,采用RT-PCR法检测细胞Bax和Bcl-2 mRNA表达水平。结果 0.25、0.5和1.0 mmol/L LaCl3染毒12、24 h均显著降低大鼠原代星形胶质细胞存活率,显著增加大鼠原代星形胶质细胞凋亡率,具有一定的剂量-反应关系。0.25、0.5和1.0 mmol/LLaCl3染毒12、24 h组大鼠原代星形胶质细胞的Bax mRNA表达水平显著高于对照组,且随染毒剂量增加而增加。此外,0.25 mmol/L LaCl3染毒24 h和0.5、1.0 mmol/L LaCl3染毒12、24 h组大鼠原代星形胶质细胞的Bcl-2 mRNA表达水平显著低于对照组,且随染毒剂量增加而下降。结论 LaCl3对大鼠原代星形胶质细胞的毒性作用可能与促凋亡基因Bax表达升高、抑凋亡基因Bcl-2表达下降而致凋亡过度有关。

Objective To study the effects of lanthanum chloride（LaCl3）on apoptosis,proapototic Bax and anti-apoptotic Bcl-2 genes expression in primary cultured astrocytes of rats.Methods Primary cultured astrocytes of cerebral cortex in rats were treated with 0,0.125,0.25,0.5 and 1.0 mmol/L LaCl3 for 12 h and 24 h.The viability of astrocytes was measured by methyl thiazolyl tetrazolium（MTT） assay,and the apoptotic rate of astrocytes was determined with flow cytometry.Astrocytic Bax and Bcl-2 mRNA expression were detected by RT-PCR.Results Treatments with 0.25,0.5 and 1.0 mmol/L LaCl3 for 12 h and 24 h significantly decreased the cell viabilities but increased the apoptotic rates in primary cultured astrocytes of a rats as dose-dependent manner.The levels of Bax mRNA expression in primary cultured astrocytes of rats treated with 0.25,0.5 and 1.0 mmol/L LaCl3for 12 and 24 h were significantly higher than control group,and increased with administrated-dose increasing.The levels of Bcl-2 mRNA expression in primary cultured astrocytes of rats treated with 0.25 mmol/L LaCl3 for 12h and 0.5 and 1.0 mmol/L LaCl3 for 12 h and 24 h were significantly lower than control group,and decreased with administrated-dose increasing.Conclusion LaCl3 could exert toxic effect on primary cultured astrocytes of rats,which may be related to the fact that LaCl3 caused excessive apoptosis by upregulating proapototic Bax expression and downregulating anti-apoptotic Bcl-2 expression.