HBx蛋白通过C/EBPα/SREBP-1通路调节脂代谢促进肝癌细胞增殖  

Hepatitis B virus X protein regulates lipid metabolism and promotes the proliferation of liver cancercells via the C/EBPa/SREBP-1 pathway

作　　者：张欣[1] 张玺 张娟娟 乔玲 Zhang Xin;Zhang Xi;Zhang Juanjuan;Qiao Ling(NHC Key Laboratory of Hormones and Development(Tianjin Medical University),Tianjin Key Laboratoryof Metabolic Diseases,Tianjin Medical University Chu Hsien-1 Memorial Hospital&Tianjin Institute of Endocrinology.Tianjin 300134,China;School of Ophthalmology&Optometry,School of Biomedical Engineering,Wenzhou Medical University,Wenzhou 325035,China)

机构地区：[1]国家卫生健康委员会激素与发育重点实验室(天津医科大学)、天津市代谢性疾病重点实验室、天津医科大学朱宪彝纪念医院&天津市内分泌研究所,300134 [2]温州医科大学眼视光学院、生物医学工程学院,325035

出　　处：《中华肝脏病杂志》2020年第12期1036-1041,共6页Chinese Journal of Hepatology

基　　金：国家自然科学基金面上项目(81370955);天津市教委科研计划项目基本科研业务费资助项目(2018KJ087)﹔天津医科大学朱宪彝纪念医院科研基金(2017DX02)。

摘　　要：目的探讨乙型肝炎病毒(HBV)编码的x蛋白(HBx)调节人肝癌细胞HepG2脂代谢和增殖的作用及其机制。方法用HBx表达质粒瞬时转染HepG2细胞,四甲基偶氮唑盐(MTT)法检测细胞增殖,油红O染色检测脂滴堆积情况,Western blot检测脂代谢相关基因CCAAT/增强子结合蛋白α (C/EBPα)、固醇调节元件结合蛋白-1 (SREBP-1)、脂肪酸合成酶(FASN)和乙酰辅酶A羧化酶1 (ACC1)的蛋白水平;MTT、油红O染色和Western blot检测C/EBPα在过表达和低表达的情况下对HBx调节HepG2细胞脂代谢和增殖的影响。组间数据比较采用方差分析。结果 HBx明显促进人肝癌细胞HepG2增殖,并呈剂量和时间依赖关系(F = 32.82,P < 0.001;F = 58.21,P < 0.001);HBx明显促进HepG2细胞的脂质堆积(F = 22.65,P < 0.001),且使脂质代谢的重要调节因子C/EBPα和SREBP-1、脂肪酸合成的限速酶FASN和ACC1的蛋白水平显著升高。C/EBPα过表达进一步加强了HBx对HepG2细胞增殖、脂滴堆积和脂生成相关基因表达的促进作用;相反,C/EBPα低表达削弱了HBx对细胞增殖、脂滴堆积和脂生成相关基因表达的促进作用。结论 HBx可能通过C/EBPα/SREBP-1信号通路,影响人肝癌细胞HepG2的脂质生成,促进其增殖。Objective To investigate the role and mechanism of hepatitis B virus(HBV)-encoded X protein(HBx)on the regulation of lipid metabolism and proliferation of human hepatoma cell line HepG2.Methods HepG2 cells were transiently transfected with HBx expressing plasmid,and the cell proliferation was detected by MTT assay.Lipid droplet accumulation condition was stained by Oil Red O.Westerm blot was used to detect the protcin levels of lipid metabolism-related genes,such as CCAAT/enhancer binding protcinα(CEBPα).sterol regulatory element binding protein-1(SREBP-1),fatty acid synthetase(FASN)and acetyl-CoA carboxylasc(ACCI).Methyl thiazolyl tetrazolium(MTT),Oil Red 0 staining and western blot were used to detect the effect of HBx on the regulation of lipid metabolism and proliferation of HepG2 cells under the conditions of overexpression and low expression of C/EBPα.Results HBx had significantly promotedthe proliferation of hepatoma cell line HepG2 in dose-and time-dependent manner(F=32.82,P<0.001;F=58.21,P<0.001).HBx had significantly promoted the lipid accumulation in HepG2 cells(F=22.65,P<0.001).Additionally,the protein levels of C/EBPα and SREBP-1(key regulatory factors of lipid metabolism),and the rate-limiting enzymcs FASN and ACCl were significantly increased.C/EBPa overexpression had further strengthened the effect of HBx on HepG2 cell proliferation,lipid droplet accumulation,and lipid production-related gene expression.On the contrary,C/EBPa low expression had weakened HBx's promotional effect on cell proliferation,lipid droplet accumulation and lipid production-related gene expression.Conclusion HBx may affect the lipid production and promote the proliferation of human hepatoma cell line HepG2 via the CEBPα/SREBP-1 signaling pathway.

关 键 词：乙型肝炎病毒X蛋白 肝细胞癌 CCAAT/增强子结合蛋白α 固醇调节元件结合蛋白-1 脂质生成 

分 类 号：R735.7[医药卫生—肿瘤]