miR - 181通过抑制Egr1在肝脏纤维化中的作用

目的 研究miR - 181在肝脏纤维化中发挥的作用及其机制，为肝脏纤维化诊断与治疗提供参考。方法 qRT - PCR检测 miR - 181在正常人和肝脏纤维化患者血清中的表达量；microRNA靶基因数据库及双荧光素酶报告基因实验预测并验证早期生长应答蛋白1（rarly growth oresponse protein - 1，Egr1）是否为miR - 181的靶基因；qRT - PCR和Western blot检测在肝星状细胞（hepatic stellated cell, HSC）中转染miR - 181mimics或miR - 181inhibitor对Egr1表达水平的影响；qRT - PCR检测血管紧张素II（angiotensin II，AngII）刺激HSC细胞后miR - 181表达水平的变化；CCK8法检测AngII和miR - 181对HSC细胞增殖的影响；qRT - PCR和western blot检测AngII和miR - 181对HSC细胞中纤维化因子α-平滑肌肌动蛋白(alpha smooth muscle Actin，α- SMA)，成纤维细胞特异性标记（FSP1）和I型胶原蛋白（Collagen I）表达的影响； HE染色和Masson’s trichrome染色观察miR - 181对CCL4小鼠肝脏纤维化的影响。结果 肝脏纤维化患者血清中miR - 181的表达量较正常对照组显著降低并伴随病理分期程度升高呈下降趋势；miR - 181可直接靶向作用于Egr1，在HSC细胞中上调miR - 181可以抑制Egr1的mRNA和蛋白的表达，而下调miR - 181则出现相反的结果；AngII刺激HSC细胞可下调miR - 181，而过表达miR - 181可抑制AngII诱导的HSC细胞增殖；在HSC细胞中上调miR - 181能抑制α- SMA，FSP1和Collagen I的表达；miR - 181过表达能抑制CCL4小鼠肝脏纤维化损伤。结论 miR - 181通过抑制Egr1从而抑制肝脏纤维化的进程，为肝脏纤维化诊断及治疗提供一种新靶点。

Investigation on miR-181 inhibition of Egr1 on hepatic fibrosis

The aim of this study was to investigate the inhibiting effect of miR-181 on Egr1 in hepatic fibrosis.Methods qRT-PCR was used to detect the expression of miR-181 in serum and pathological staging of liver fibrosis in normal people and patients with liver fibrosis. MicroRNA target gene database was screened, and Egr1 was the potential target gene of miR-181. The effect of miR-181 mimics on Egr1 protein expression was detected by western blot. The expression levels of miR-181 and AngⅡ induced cell proliferation were detected by q RT-PCR. qRT-PCR detections of miR-181 and alpha SMA, FSP1 and expression of Collagen Ⅰ were conducted. Effects of miR-181 on hepatic fibrosis were observed by HE staining and Masson’s trichrome staining. Results The expression of miR-181 in serum was significantly lower in patients with liver fibrosis than in the control group. miR-181 mimics inhibited the expression of Egr1 m RNA and protein. miR-181 inhibited AngⅡ-induced hepatic cell proliferation. miR-181 inhibited alpha SMA, FSP1 and Collagen Ⅰ expression. miR-181 inhibited hepatic fibrosis injury in mice. Conclusion miR-181 inhibited the progression of liver fibrosis by inhibiting Egr1, providing a new target for diagnosis and treatment of liver fibrosis.