The angiogenic role of circRNA-007371 in liver fibrosis [circRNA Microarray]

Objective Circular RNAs (circRNAs) are covalently closed, endogenous non-coding RNAs. CircRNAs play a vital role in liver diseases, acting as microRNA (miRNA) sponges. However, the angiogenic role of circRNA remains unknown in liver fibrosis and is the focus of this study. Methods Liver fibrosis was induced by thioacetamide (TAA), or carbon tetrachloride (CCl4) in mice. CircRNA-microarray, AGO2-RNA immunoprecipitation (RIP), and RNA-seq were utilized to explore the hepatic circRNAs profile. The qPCR and PCR-gel electrophoresis analysis were used to investigate the characterization of circRNA-007371. Liver tissues and EMOA murine endothelial cells were used to verify the angiogenic mechanism of circRNA-007371. Results The increased collagen deposition, pseudolobule formation, and angiogenesis were observed in murine liver induced by TAA and CCl4. CircRNA-microarray in TAA-induced fibrotic murine liver indicated that the expression of circRNA-007371 was up-regulated. Moreover, AGO2-RIP and PCR analysis showed that circRNA-007371 had the characterization of circRNAs and played a role as competing endogenous RNAs (ceRNA) sponging miR-200a. In vitro, circRNA-007371 promoted the ability of migration, growth, and blood vessel formation in EMOA murine endothelial cells using wound healing and tube formation assay. The AGO2-RIP and RNA-sequencing analysis in overexpression circRNA-007371 EMOA murine endothelial cells demonstrated that circRNA-007371 upregulates the stromal antigen 1 (Stag1) via spouse of miR-200a and HIF-1 signaling pathway might participate in the angiogenesis. Conclusions This study discovers that circRNA-007371, a novel ceRNA, is up-regulated, and enhances the angiogenesis via angiocrine role to regulate the STAG1-miR-200a-5p signaling pathway in liver fibrosis. 1. One liver fibrosis model was induced by intraperitoneal injection of thioacetamide (TAA) in C57BL/6J mice for 8 weeks. Control mice received the same volume of normal saline (NS). Another model was induced by intraperitoneal injection of carbon tetrachloride (CCl4) in C57BL/6J mice for 6 weeks. Control mice received the same volume of olive oil. 2. The mouse hemangioendothelioma endothelial cells (EOMA) were transfected with circRNA-007371 overexpression plasmid.