利拉鲁肽对人HepG2肝细胞脂代谢的影响及作用机制

Effects of liraglutide on lipid metabolism in human HepG2 liver cells and its related mechanism

目的 :建立Hep G2肝细胞脂肪变性模型,了解利拉鲁肽是否可改善Hep G2细胞内脂代谢状态,并对相关机制进行初步探讨。方法:软脂酸钠诱导建立Hep G2肝细胞脂肪变性模型,并给予利拉鲁肽干预。油红O染色确定Hep G2肝细胞脂肪变性模型的建立。Western blot检测Hep G2中脂质合成和分解关键酶蛋白水平的变化情况及Hep G2中PI3K信号通路活化情况。采用PI3K信号通路抑制剂预处理Hep G2细胞,观察PI3K信号通路在软脂酸钠诱导建立Hep G2肝细胞脂肪变性中的作用。结果:油红O染色结果显示模型建立成功。Western blot结果显示,软脂酸钠诱导可显著升高Hep G2中固醇调节元件结合蛋白1c(sterol regulatory element-binding protein1c,SREBP1c)、脂肪酸合成酶(fatty acid synthase,FAS)的蛋白水平,降低脂肪甘油三酯脂酶(adipose triglyceride lipase,ATGL)的蛋白水平(P<0.01),并上调Hep G2中PI3K信号通路活化水平;与软脂酸钠组相比,利拉鲁肽干预可显著降低Hep G2中SREBP1c、FAS的蛋白水平,升高ATGL的蛋白水平,并抑制Hep G2中PI3K信号通路活化水平;阻断Hep G2中的PI3K信号通路后,软脂酸钠诱导Hep G2脂肪变性的能力显著降低(P<0.01)。结论:利拉鲁肽可通过调节Hep G2中的PI3K信号通路,进而改善Hep G2细胞的脂代谢情况。

Objective：We established a Hep G2 hepatic steatosis model to observe whether liraglutide improves lipid metabolism in Hep G2 liver cells,and discuss the related mechanisms. Methods：Sodium palmitate was performed to induce Hep G2 steatosis model,and liraglutide intervention was given. Oil Red O staining was performed to determine the establishment of Hep G2 hepatic steatosis model. Key enzyme of lipid synthesis and degradation as well as the activation of PI3 K signaling pathway in Hep G2 liver cells were detected by Western blotting assay. To observe the effect of PI3 K signaling pathway in sodium palmitate induced Hep G2 hepatic steatosis,Hep G2 liver cells was pretreated with PI3 K signaling pathway inhibitor. Results：Oil Red O staining showed that the model was successfully established. Western blotting assay showed that sodium palmitate significantly increased the expression of sterol regulatory element-binding protein1c（SREBP1c）and fatty acid synthase（FAS）protein levels in Hep G2 liver cells,and decreased adipose triglyceride lipase（ATGL）protein levels（P〈0.01）; sodium palmitate activated PI3 K signaling pathway in Hep G2 liver cells.Compared with sodium palmitate,liraglutide significantly decreased the expression of SREBP1 c and FAS protein levels in Hep G2 liver cells,and increased ATGL protein levels; liraglutide inhibited PI3 K signaling pathway in Hep G2 liver cells. After blocking PI3 K signaling pathway,sodium palmitate-induced steatosis of Hep G2 liver cells was significantly reduced（P〈0.01）. Conclusion：By regulating PI3 K signaling pathway in Hep G2 liver cells,liraglutide improves lipid metabolism in Hep G2 liver cells.