脂多糖对HepG2细胞胰岛素抵抗的影响

目的探讨脂多糖(LPS)对人肝癌细胞株HepG2细胞胰岛素抵抗(IR)的影响。方法以高浓度的胰岛素作用于人肝癌细胞株HepG2细胞建立胰岛素抵抗模型。HepG2细胞分为对照组、模型组、脂多糖组、模型加脂多糖组。采用细胞培养、葡萄糖摄取分析、蒽酮法及糖原染色等方法检测不同浓度胰岛素及不同作用时间对HepG2细胞胰岛素抵抗的影响,各组细胞葡萄糖摄取及糖原含量的变化。结果浓度为5×10-7 mol/L的胰岛素作用24 h成功建立HepG2细胞的IR模型。葡萄糖摄取分析结果显示,脂多糖组与对照组相比,基础特异性转运和胰岛素特异性转运无统计学差异(P>0.05),模型加脂多糖组的基础特异性转运比对照组明显降低(P<0.01),胰岛素刺激的特异性转运比对照组和模型组都明显降低(P<0.01)。脂多糖组培养液内的糖原含量与对照组相比无统计学差异(P>0.05),模型加脂多糖组培养液内的糖原含量比对照组明显下降(P<0.01)。PAS染色观察,模型加脂多糖组的糖原颗粒与模型组相比更为少见。结论少量多次的LPS刺激可加重HepG2细胞的IR,推断在非酒精性脂肪性肝病的发生发展中,肠源性内毒素血症可能与IR互为因果并造成恶性循环。

Influence of lipopolysaccharide on insulin resistance of HepG2 cells

Objective To investigate the influence of lipopolysaccharide(LPS) on insulin resistance(IR) of HepG2 cells.Methods The IR model was established with high concentration insulin acting on HepG2 cells,and then HepG2 cells were divided into control group,model group,LPS group and combining group.The influence of insulin in different-dose insulin and at different action time on IR of HepG2 cells,and changes of glucose uptake and glycogen level were detected by using cell culture,glucose uptake analysis,anthrone method and PAS staining.Results The IR model was successfully established in HepG2 cells after the action of 5×10-7 mol/L insulin for 24 hours.The analysis of glucose uptake showed that basic unitransport and unitransport of insulin had no statistical difference between LPS group and control group(P>0.05).The basic unitransport decreased significantly in combining group than that in control group(P<0.01),and insulin unitransport was significantly lower in combining group than that in control group and model group(P<0.01).The glycogen level in LPS group had no statistical difference compared with control group(P>0.05) and decreased significantly in combining group compared with control group(P<0.01).The result of PAS staining showed that glycogenosomes were less in combining group than those in model group.Conclusion A little and frequent LPS stimulation can exacerbate IR in HepG2 cells.It is deduced that intestinal endotoxemia and IR are causal and induce vicious circle in the development of nonalcoholic fatty liver disease.