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目的:研究Rho信号横纹肌激活剂(the striated muscle activator of Rho signaling,STARS)在棕榈酸诱导的肌细胞胰岛素抵抗中的作用及其机制。方法:采用棕榈酸(palmitic acid,PA)孵育L6成肌细胞构建胰岛素抵抗模型,包括对照组和棕榈酸组,并通过质粒上调STARS的表达,包括对照组,空质粒组(pc DNA),STARS过表达组(pc DNA/STARS),棕榈酸组(PA),棕榈酸空质粒组(PA+pc DNA),棕榈酸STARS过表达组(PA+pc DNA/STARS),以及si RNA下调肌细胞中STARS的表达,包括对照组,si RNA阴性对照组(NC-si RNA),STARS敲低组(si-STARS),棕榈酸组(PA),棕榈酸si RNA阴性对照组(PA+NC-si RNA),棕榈酸STARS敲低组(PA+si-STARS)研究STARS在骨骼肌胰岛素抵抗中的作用以及其下游信号通路。采用RT-PCR及Western blot方法检测各组STARS、血清应答因子(serum response factor,SRF)、巨核细胞白血病因子1(megakaryoblastic leukemia 1,MKL1)、AKT、IRS-1,以及GLUT4 m RNA和蛋白表达水平。结果:与对照组相比,PA组STARS m RNA和蛋白的表达明显增加(均P=0.000);STARS上调组肌细胞STARS m RNA和蛋白表达均明显增加(均P=0.000),IRS-1(P=0.000)、GLUT4(P=0.000)和AKT m RNA(P=0.000)表达明显下降,AKT丝氨酸磷酸化水平(P=0.000)和GLUT4(P=0.000)蛋白的表达显著降低,IRS-1丝氨酸磷酸化水平显著增加。下调STARS的表达后出现了与上述相反的结果。经上述干预后,SRF和MKL1基因和蛋白水平均没有明显变化。结论:STARS与胰岛素敏感性密切相关,但其下游靶点MKL1和SRF没有变化。可能通过影响其修饰后翻译,也可能通过其他信号通路在胰岛素抵抗中发挥作用,需要进一步研究。
Objective: To investigate the role and mechanism of Rho signal striae muscle activator of Rho signaling (STATS) in palmitate-induced myocyte insulin resistance. Methods: L6 myoblasts were incubated with palmitic acid (PA) to construct insulin resistance model, including control group and palmitic acid group. The plasmid was used to up-regulate the expression of STARS, including control group, pcDNA, STARS PcDNA / STARS, PA, PA + pcDNA, PA + pc DNA / STARS, and si RNA down-regulated muscle cells Including the control group, the si RNA negative control group, the si-STARS group, the palmitic acid group (PA), the palmitic acid RNA negative control group (PA + NC- si RNA) and STARS knockdown group (PA + si-STARS) were used to investigate the role of STARS in skeletal insulin resistance and its downstream signaling pathway. The expression of STARS, serum response factor (SRF), megakaryoblastic leukemia 1 (MKL1), AKT, IRS-1 and GLUT4 mRNA and protein were detected by RT-PCR and Western blot. Level. Results: Compared with the control group, the expression of STARS m RNA and protein in PA group were significantly increased (all P = 0.000); the expression of STARS m RNA and protein in STARS group were significantly increased (all P = 0.000); IRS-1 (P = 0.000), GLUT4 (P = 0.000) and AKT m RNA (P = 0.000), the phosphorylation levels of AKT (P = 0.000) and GLUT4 1 serine phosphorylation level increased significantly. The opposite result was shown after down-regulating the expression of STARS. After the above intervention, SRF and MKL1 gene and protein levels did not change significantly. Conclusion: There is a close relationship between STARS and insulin sensitivity, but there is no change in its downstream target MKL1 and SRF. May affect its modified translation, may also play a role in insulin resistance through other signaling pathways, further study is needed.