抵抗素上调脂肪酸转位酶表达对HepG2细胞脂质积聚的作用

摘要

Objective To investigate the role of recombinant human resistin (rh-resistin) in the palmitate inducing intracellular lipid accumulation in HepG2 cells and explore the effect of rh-resistin on fatty acid translocase(FAT/CD36).Methods Cells were treated with or without 50 ng/ml rh-resistin in the same condition, followed by serum-starving in glucose-free DMEM for 3~5 hours in the continued presence or absence of rh-resistin.Then cells were incubated with 0.5 mmol/L palmitate for 16 h followed by with or without 100 nmol/L insulin for 2 hours.Sterol regulatory element binding protein1 (SREBP1) mRNA expression levels were determined by real time RT-PCR.The cell surface CD36 content was measured by immunofluorescent flow cytometry analysis.The lipid accumulation in cells was determined by Nile red staining, and images were obtained on a Laser Scanning Confocal Microscope.Results Incubation with 0.5 mmol/L palmitate, in both basal and insulin-stimulated conditions, rh-resistin increased cell surface CD36 content, stimulated SREBP1 mRNA expressions and exacerbated intracellular lipid accumulation in HepG2 cells.Conclusions In the high concentration of free saturated fatty acid environment, resistin in the basal and insulin could stimulate state by up-regulating HepG2 CD36 expression, stimulate SREBP-1 transcription, leading to HepG2 liver cell intracellular lipid accumulation.%目的 探讨抵抗素在棕榈酸诱导下对HepG2肝细胞脂质积聚的作用及其对脂肪酸转位酶(FAT/CD36)表达调控的影响.方法 50 ng/ml重组人抵抗素及0.5 mmol/L棕榈酸孵育HepG2肝细胞,之后用100 nmol/L胰岛素处理,采用实时定量RT-PCR检测胆固醇调节元件结合蛋白(SREBP)1 mRNA水平,流式细胞仪检测胞膜CD36表达,尼罗红(Nile Red)染色后激光共聚焦显微镜检测胞内脂质含量.结果 与对照组相比,抵抗素增加胞膜FAT/CD36含量(P<0.05),促进HepG2细胞SREBP1 mRNA表达(P<0.05),使胞内红色脂肪小滴增多(P<0.05).结论 在高浓度游离饱和脂肪酸环境中,抵抗素在基础及胰岛素刺激状态下通过上调HepG2 的CD36 表达,刺激SREBP1转录,导致HepG2肝细胞内脂质积聚.