TNF-α促进HepG2肝细胞脂质积聚及其机制的初步研究  

TNF-α promotes HepG2 hepatocytes lipid accumulation

作　　者：陈书梅[1] 杨淑敏[1] 张文龙[1] 吕琼[1] 叶鹏[1] 高茹菲[1] 梅玫[1] 汪志红[1] 李启富[1] 

机构地区：[1]重庆医科大学附属第一医院内分泌科,重庆400016

出　　处：《第三军医大学学报》2013年第11期1088-1092,共5页Journal of Third Military Medical University

基　　金：国家自然科学基金面上项目(81170751);国家临床重点专科建设项目(2011)~~

摘　　要：目的探讨肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)是否能够促进肝细胞脂质积聚,并对其机制进行初步探讨。方法将HepG2肝细胞分为空白对照组、单纯TNF-α组(TNF-α2ng/mL或20ng/mL)、软脂酸组(软脂酸0.08mmol/L或0.2mmol/L)及联合组(TNF-α2ng/mL联合软脂酸0.08mmol/L、TNF-α2ng/mL联合软脂酸0.2mmol/L、TNF-α20ng/mL联合软脂酸0.08mmol/L、TNF-α20ng/mL联合软脂酸0.2mmol/L),处理24h,应用化学酶促-比色法定量检测细胞内TG含量。进一步选取TNF-α20ng/mL和软脂酸0.08mmol/L,通过油红O染色观察HepG2细胞内脂质积聚情况;实时荧光定量PCR和Western blot检测HepG2细胞SREBP-1、FAS、ACCα的表达水平。结果①单纯TNF-α组TG含量[TNF-α2ng/mL组(0.344±0.093)μg/μg、TNF-α20ng/mL组(0.329±0.068)μg/μg]分别较空白对照组[(0.192±0.048)μg/μg]显著升高(P<0.05);联合组[TNF-α2ng/mL联合软脂酸0.08mmol/L组(0.451±0.096)μg/μg、TNF-α2ng/mL联合软脂酸0.2mmol/L组(0.821±0.257)μg/μg、TNF-α20ng/mL联合软脂酸0.08mmol/L组(1.032±0.286)μg/μg、TNF-α20ng/mL联合软脂酸0.2mmol/L组(2.134±1.049)μg/μg]分别较软脂酸组[软脂酸0.08mmol/L组(0.247±0.069)μg/μg、软脂酸0.2mmol/L组(0.341±0.031)μg/μg]显著升高(P<0.05);②油红O染色进一步显示,TNF-α促进肝细胞内脂质积聚。③实时荧光定量PCR和Western blot检测结果显示单纯TNF-α组与空白对照组相比,HepG2细胞SREBP-1、FAS、ACCα的表达均增加(P<0.05);联合组与软脂酸组相比,肝细胞内SREBP-1、FAS、ACCα的表达水平明显上调(P<0.05)。结论TNF-α促进HepG2肝细胞内脂质积聚,增加SREBP-1、FAS、ACCα的表达。Objective To determine the effect of tumor necrosis factor-α （TNF-α） on lipid accumulation in HepG2 cells and its underlying possible mechanism. Methods HepG2 cells were treated with TNF-α （2 or 20 ng/mL）, palmitate （PA, 0.08 or 0.2 mmol/L）, and TNF-α plus palmitate （combination of the 2 doses of 2 agents） for 24 h, respectively. The intracellular triglyceride （TG） was measured by enzymatic colorimetric method. Then TNF-α of 20 ng/mL and palmitate of 0.08 mmol/L was chosen for the further experiment. Lipid accumulation in the HepG2 cells was observed with Oil Red O staining. Real-time PCR and Western blot analysis were used to detect the expression of SREBP-1, FAS and ACCα at mRNA and protein levels. Results TG level was significantly higher in TNF-α treated cells （0.344±0.093 and 0.329±0.068 μg/μg for the doses of 2 and 20 ng/mL） than in control cells （0.192±0.048 μg/μg, P〈0.05）. And that of the combination treatment cells （TNF-α 2 ng/mL plus PA 0.08 mmol/L： 0.451±0.096, TNF-α 2 ng/mL plus PA 0.2 mmol/L： 0.821±0.257, TNF-α 20 ng/mL plus PA 0.08 mmol/L： 1.032±0.286, TNF-α 20 ng/mL plus PA 0.2 mmol/L： 2.134±1.049 μg/μg） was significant higher than the cells treated by PA alone （PA 0.08 mmol/L： 0.247±0.069, PA 0.2 mmol/L： 0.341±0.031 μg/μg, all P〈0.05）. Oil red O staining also showed that TNF-α promoted lipid accumulation in HepG2 cells. The expression of SREBP-1, FAS and ACCα at mRNA and protein levels was significantly higher in TNF-α treatment and the TNF-α plus PA treatment cells than in control cells （P〈0.05）. Conclusion TNF-α promotes lipid accumulation, and enhances the expression of SREBP-1, FAS and ACCα in HepG2 hepatocytes.

关 键 词：TNF-Α 软脂酸 SREBP-1 HepG-2肝细胞 脂质积聚 

分 类 号：R322.47[医药卫生—人体解剖和组织胚胎学] R341.32[医药卫生—基础医学]