丙型肝炎病毒1b基因型核心蛋白对HepG2细胞Bax与Bcl-2基因表达的影响

摘要

目的 研究丙型肝炎病毒(HCV)1b基因型核心蛋白(C)对HepG2细胞B细胞淋巴瘤-2基因(Bcl-2)与Bcl-2相关X蛋白(Bax)表达的影响,以探索1b型HCV C蛋白与HepG2细胞凋亡的关系.方法 利用RT-PCR扩增出HCV-1b-C基因,经双酶切后连接pcDNA3.1(-),成功构建真核表达载体pcDNA3.1(-)/HCV-1b-C.利用脂质体转染HepG2细胞,RT-PCR及Western Blot检测其mRNA及蛋白的表达,RT-PCR及Western Blot检测转染成功后HCV-1b-C对HepG2细胞Bax与Bcl-2表达的影响,并设转染空质粒组及未处理组作对照.结果 成功构建真核表达载体pcDNA3.1(-)/HCV-1b-C;瞬时转染HepG2细胞,成功表达HCV C mRNA及蛋白;转染C基因组的Bax的mRNA及蛋白相对表达量减少,与转染空质粒组及未处理组比较差异均有统计学意义(P<0.01);转染C基因组的Bcl-2的mRNAR蛋白相对表达量增多,与转染空质粒组及未处理组比较差异均有统计学意义(P<0.01).结论 1b基因型HCV C蛋白转染HepG2细胞会导致Bax表达减少及Bcl-2表达增多,降低Bax/Bcl-2比值,可能是抑制HepG2细胞凋亡的机制之一.%Objective To investigate the effects of hepatitis C virus genotype 1b core protein on the expression of Bax and Bcl-2 in the HepG2 cell and to study the relationship of core protein and cell apoptosis.Methods The gene of HCV-1b-C was amplified by RTPCR,and then it was inserted into pcDNA3.1(-) to construct the expression plasmid pcDNA3.1(-)/HCV-1b-C by double enzyme-cut.To transfect the HepG2 cell with recombination expression vector, pcDNA3.1(-)/ HCV-1b-C, by lipofectamine.The expression of HCV C mRNA and protein was detected by RT-PCR and Western Blot respectively.And then, detect the effects of HCV-1b-C on the expression of Bax and Bcl-2 gene in the HepG2 cell by RT-PCR and Western Blot, and set groups transfect with the plasmid pcDNA3.1(-) and normal groups as control.Results The expression vector pcDNA3.1(-)/ HCV-1b-C was constructed successfully; And then, HCV C protein was expressed in the HepG2 cell line by transfection; For the corresponding mRNA and protein expression of Bax were lower in the groups transfected with HCV-1b-C compare to those in the groups transfected with the empty plasmid and normal groups(P＜0.01); For the corresponding mRNA and protein expression of Bcl-2 were higher in the groups transfected with HCV-1b-C than those of in groups transfected with the empty plasmid and normal groups(P＜0.01).Conclusion The expression of genotype 1b HCV C in the HepG2 cell can reduce the expression of Bax and increase the expression of Bcl-2, leading to decrease in the ratio of Bax /Bcl-2, considering one of the mechanism of HepG2 cell escape from cell apoptosis.