骨桥蛋白通过内质网应激诱导C2C12肌细胞胰岛素抵抗

发布时间：2018-10-09 11:08

【摘要】：目的:探讨骨桥蛋白(osteopontin,OPN)对C2C12肌细胞胰岛素抵抗的影响及其可能的机制。方法:低血清培养辅以胰岛素处理诱导C2C12成肌细胞分化为C2C12肌细胞,蛋白免疫印迹检测蛋白质的表达,离心法分离细胞膜,葡萄糖摄取试剂盒定量葡萄糖摄取。结果:(1)骨桥蛋白以剂量依赖和时间依赖方式抑制胰岛素刺激的蛋白激酶B(Akt)的磷酸化,并抑制胰岛素所致的葡萄糖转运体4(Glut4)膜位移和葡萄糖的摄取;而特异性的抗OPN受体CD44抗体预处理可逆转上述变化。(2)OPN可诱导C2C12肌细胞的内质网应激,并促进c-Jun氨基端激酶(JNK)的磷酸化。(3)内质网应激抑制剂4-苯基丁酸(4-PBA)可降低OPN所增加的JNK磷酸化,恢复胰岛素刺激所致的Glut4的膜位移以及葡萄糖摄取。结论:骨桥蛋白通过诱导C2C12肌细胞内质网应激导致胰岛素抵抗。本研究为揭示骨桥蛋白在胰岛素抵抗和糖尿病中的作用提供了新的实验依据和理论解释。
[Abstract]:Aim: to investigate the effect of osteopontin (osteopontin,OPN) on insulin resistance of C2C12 myocytes and its possible mechanism. Methods: C2C12 myoblasts were induced to differentiate into C2C12 myocytes by low serum culture and insulin treatment. Western blot was used to detect the expression of protein. Cell membrane was isolated by centrifugation and glucose uptake kit was used to quantify glucose uptake. Results: (1) osteopontin inhibited the phosphorylation of insulin-stimulated protein kinase B (Akt), insulin-induced glucose transporter 4 (Glut4) membrane displacement and glucose uptake in a dose-and time-dependent manner. The specific pretreatment of CD44 antibody against OPN receptor can reverse these changes. (2) OPN can induce endoplasmic reticulum stress in C2C12 myocytes. (3) 4-phenylbutyric acid (4-PBA), an inhibitor of endoplasmic reticulum stress, could decrease the JNK phosphorylation increased by OPN, and restore the membrane shift and glucose uptake of Glut4 induced by insulin stimulation. Conclusion: osteopontin induces insulin resistance by inducing endoplasmic reticulum stress in C2C12 myocytes. This study provides a new experimental basis and theoretical explanation for revealing the role of osteopontin in insulin resistance and diabetes.
【作者单位】：连云港市第一人民医院病理科;武汉大学基础医学院病理生理学教研室;
【基金】：国家自然科学基金资助项目(No.30770758/H0178)
【分类号】：R329.2

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