环状RNA hsa_circ_0072765靶向结合miR-370促进肝纤维化相关机制研究

The activation of hepatic stellate cell (HSC) is the critical role in the hepatic fibrosis. Circular RNAs (circRNAs) act as competing endogenous RNAs (ceRNAs) which sponge with miRNAs to regulate the progression of HSC activation and hepatic fibrogenesis. Previous evidences suggested that circRNA hsa_circ_0072765 was significantly up-regulated in activated HSC. MiR-370 inhibits the activity of the Hedgehog (Hh) signal pathway by targeting Smoothened (SMO) to suppressing hepatic fibrosis. We predict that hsa_circ_0072765 acting as a sponge of miR-370 which could competitively inhibit the expression of miR-370 by bioinformatics, but its role in hepatic fibrosis and the mechanism is not clear yet. We will detect the differential expression of hsa_circ_0072765 in the fibrotic liver tissues and serums from patients or experimental rats model. Then using adenovirus vector to regulate the expression of hsa_circ_0072765, and the effects on biological activity of HSC, and the expression of miR-370 and Hh signal pathway were detected in vitro and in vivo. Generally, this study will reveal the effect and mechanism of hsa_circ_0072765/miR-370/Hh signal pathway regulatory network on the hepatic fibrogenesis and may provide potential target for the treatment of hepatic fibrosis.

HSC活化是肝纤维化发生发展的中心环节。环状RNA(circRNAs)能竞争结合miRNAs调控HSC活性和肝纤维化进程。既往研究发现circRNA hsa_circ_0072765在活化HSC中表达上调，且miR-370作用于跨膜蛋白(SMO)下调Hh信号通路活性抑制肝纤维化。生物信息学预测hsa_circ_0072765通过海绵吸附作用下调miR-370表达，但其在肝纤维化进程中的机制尚未明确。本课题拟检测hsa_circ_0072765在人和大鼠肝纤维化模型肝组织及血清中的差异表达，利用腺病毒载体在体内、外调控hsa_circ_0072765表达，检测对miR-370和Hh信号通路、HSC生物学活性的影响，探讨hsa_circ_0072765/miR-370/Hh信号通路调控网络在肝纤维化进程中的作用及分子机制，为肝纤维化治疗提供新的靶点。

肝星状细胞（HSC）活化是肝纤维化发生发展的中心环节，环状RNA(circRNAs)能竞争结合miRNAs调控HSC活性和肝纤维化进程。本研究发现circRNA hsa_circ_0072765在肝硬化肝组织及活化HSC中表达上调，通过sponge竞争结合miR-370下调其表达，从而上调miR-370靶基因跨膜蛋白(SMO)的表达。通过生物信息学分析及构建报告基因证实SMO是miR-370的靶基因，而miR-370是hsa_circ_0072765靶基因，hsa_circ_0072765通过海绵吸附作用下调miR-370表达。本实验利用腺病毒下调HSC中hsa_circ_0072765表达，表明下调hsa_circ_0072765后，SMO及其下游基因 Gli-1、Snail-1表达下调，而miR-370表达上调；肝纤维化相关指标α-SMA、COL-III、TIMP1表达下调，MMP2表达上调。体内利用腺病毒抑制hsa_circ_0072765的表达，能有效抑制肝纤维化的进程。本研究证实，hsa_circ_0072765通过海绵吸附作用下调miR-370表达，再靶向作用于Hh信号通路的SMO，促进HSC的活化，加速肝纤维化进程；而抑制hsa_circ_0072765的表达可部分逆转肝纤维化进程；可能为肝纤维化的治疗提供新的靶点。