·糖尿病基础研究·

　　李兰芳 陈临溪 郭玉 曹轩 喻翠云 唐国涛

　　基金项目：国家自然科学基金资助项目(30901577);湖南省衡阳市科技局资助项目(2009KJ14)

　　作者单位：421001湖南衡阳，南华大学药物药理研究所

　　【摘要】目的探讨NADPH氧化酶(NOX)在肿瘤坏死因子α(TNF-α)诱导的肝细胞胰岛素抵抗(IR)中的作用。方法用TNF-α(4 ng/ml)刺激HepG2细胞48 h，建立IR细胞模型。蒽酮法测定细胞内糖原水平;DCFH-DA探针标记，流式细胞仪检测细胞内活性氧(ROS)水平;Western blot观察胰岛素受体底物1(IRS1)和p-IRS1水平。结果 TNF-α处理后，细胞内ROS水平增加，细胞内糖原含量显著降低。NOX的抑制剂DPI显著抑制TNF-α诱导的ROS产生，并且促进细胞内糖原的合成，同时逆转TNF-α对胰岛素信号通路的影响。结论TNF-α通过激活NOX促进细胞内ROS水平增加，抑制NOX源性的ROS可以改善糖原合成。

　　【关键词】HepG2细胞;肿瘤坏死因子α;胰岛素抵抗;氧化应激

　　doi:10.3969/j.issn.1006-6187.2012.01.019

　　Mechanism of TNF-α-induced hepatic insulin resistanceLI Lan-fang, CHEN Lin-xi, GUO Yu, et al. Institute of Pharmacy and Pharmacology， University of South China， Hu′nan Hengyang 421001, China

　　【Abstract】ObjectiveTo demonstrate the key role of NADPH oxidase (NOX) derived ROS in TNF-α-induced hepatic insulin resistance.MethodsCultured HepG2 cells were treated for 48 h with 4ng/ml TNF-α to prepare a cellular model of insulin resistance. ROS level was determined by DCF-DA and FACS. The expression of IRS1 and p-IRS1 was analyzed by Western blot.ResultsIn cultured HepG2 cells, TNF-α induced the decrease of glycogen and the increase of ROS. TNF-α down-regulated the level of IRS1 and stimulated its inhibited phosphorylation on Ser307. DPI can reverse the effect of TNF-α.ConclusionsThe effects of TNF-α on hepatic insulin resistance appear to be, at least in part, mediated by NOX-derived ROS.

　　【Key words】HepG2 cells; Tumor necrosis factor α; Insulin resistance; Oxidative stress