NF-κB诱捕分子在2型糖尿病患者脂肪组织胰岛素抵抗中的作用

Inhibitory effect of NF-κB decoy on insulin resistance in adipocytes of patients with type 2 diabetes mellitus

目的探讨2型糖尿病(T2DM)患者脂肪细胞内异常胰岛素信号转导与核因子(NF)-κB活化的关系;研究NF-κB靶向诱捕分子(NF-κBdecoy)在体外对胰岛素抵抗的作用。方法取T2DM患者及非糖尿病患者腹部皮下脂肪组织进行原代培养,用免疫沉淀法及蛋白质印迹法检测两组脂肪细胞内胰岛素刺激后胰岛素信号转导分子胰岛素受体底物(IRS)-1酪氨酸磷酸化及Akt-Ser473磷酸化程度,用电泳迁移率变动分析(EMSA)测定两组脂肪细胞内NF-κB的活性;脂质体瞬时转染法将NF-κBdecoy分子转入T2DM患者脂肪细胞内,再检测转染后上述胰岛素信号分子及NF-κB的活性。结果T2DM患者脂肪细胞内IRS-1酪氨酸磷酸化及Akt-Ser473磷酸化水平明显低于非糖尿病患者(P<0.05),NF-κB的活性明显高于非糖尿病患者(P<0.01);转染NF-κBdecoy分子后T2DM患者脂肪细胞内NF-κB的活性较转染前明显降低(P<0.05),IRS-1酪氨酸磷酸化及Akt-Ser473磷酸化水平较转染前有明显升高(P<0.05)。结论T2DM患者的腹部皮下脂肪细胞存在胰岛素抵抗(IR)和NF-κB过度活化;NF-κB靶向诱捕分子体外能部分逆转胰岛素抵抗作用。

Objective To investigate the relationship of abnormal insulin signal transduction with NF-κB activation in the adipose tissue of patients with type 2 diabetes mellitus（T2DM） ,and to study the effect of NF-κB decoy on insulin resistance in vitro. Methods Decoy targeting NF-κB was designed and synthesized. Adipocytes from abdominal subcutaneous adipose tissues were obtained from T2DM patients and non-diabetic patients. The phosphorylation of insulin signal transduction molecules IRS-1 tyrosine and Akt-Ser473 of adipocytes were examined by immunoprecipitation and Western blotting analysis after stimulation with insulin. The activity of NF-κB in the adipocytes was analyzed by electrophoretic mobility shift assay （EMSA）. The NF-κB decoy was transfected into the adipocytes of T2DM patients via liposome. Results The phosphorylation levels of insulin signal transduction molecule IRS-1 tyrosine and Akt-Ser473 in adipocytes T2 DM patients were significantly less than that in adipocytes from non-diabetes mellitus controls（ P 〈 0. 05）. The activity of NF-κB in adipocytes of T2 DM patients was significantly higher than that in the controls（ P 〈 0. 01）. After transfection of NF-κB decoy,the activity of NF-κB was decreased compared with that before transfection（ P 〈 0. 05） ,and the phosphorylation levels of IRS-1 tyrosine and Akt-Ser473 in adipocytes of T2 DM patients were significantly increased compared with those before transfection（ P 〈 0. 05）. Conclusion Insulin resistance and excessive activation of NF-κB exist in the adipocytes of patients with T2DM; NF-κB decoy can partly ameliorate insulin resistance.