关键词: 过氧化氢, 线粒体氯通道蛋白, C6细胞, 细胞凋亡

Abstract: Abstract:Objective To observe the effect of lipopolysaccharide (LPS) on malignant glioma C6 cells injuried by hydrogen peroxide (H₂O₂),investigate the mechanism maybe involved.Methods The experiment was divided into four groups: control group,100 μmol•L^-1 LPS group,1 000 μmol•L^-1 H₂O₂ group and LPS combined with H₂O₂ treatment group.After C6 cells were treated by drugs for 6 h,the LDH release rate was detected by ultraviolet spectrophotometry with LDH detecting kit,the apoptotic rate of C6 cells was determined by TUNEL,the Bcl-2,Bax,Caspase-3 mRNA levels were detected by RT-PCR and Bcl-2,the Bax,Caspase-3,Cyt-C,and CLIC4 protein levels were detected by Western blotting.Results Compared with control group,the apoptotic rate and LDH release rate increased in LPS group (P<0.05),the expression levels of Bcl-2,Bax mRNA did not change (P>0.05),the expression levels of Caspase-3 mRNA was higher than that in control group (P<0.05),but the Bcl-2,Bax,CLIC4 and cytosolic Cyt-C protein expression levels did not change (P>0.05),the expression level of Caspase-3 protein increased(P<0.05).Compared with control group,the apoptotic rate and LDH release rate increased in 1 000 μmol•L^-1 H₂O₂ treatment group (P<0.05),the expression of Bcl-2 mRNA decreased compared with control group (P<0.05),the expression levels of Bax and Caspase-3 mRNA increased compared with control group (P<0.05); but the expression level of Bcl-2 protein decreased,the Bax,Caspase-3,CLIC4 and cytosolic Cyt-C protein expression levels increased obviously (P<0.05).When compared with H₂O₂ group and LPS group,the apoptotic rate and LDH release rate increased in LPS combined with H₂O₂ treatment group (P<0.05),the expression level of Bcl-2 mRNA decreased,the expression levels of Bax and Caspase-3 mRNA increased (P<0.05); the expression level of Bcl-2 protein decreased,the Bax,Caspase-3 and cytosolic Cyt-C protein expression levels increased obviously compared with control group (P<0.05). and the CLIC4 protein expression did not change(P>0.05).Conclusion LPS can activate Caspase-3 signal pathway,induce the early apoptotic event of C6 cells.Meanwhile,the LPS combined with H₂O₂ can aggravate the injury of C6 cells induced by H₂O₂ through the overactivation of apoptosis relative Bcl-2/Bax and Caspase-3 pathway.The function of mitochondrial chloride intracellular channel CLIC4 seems uneffective.

Key words: hydrogen peroxide, mitochondria chloride channel, C6 cell, apoptosis