Abstract
Angipoietin-1 (Angpt1) and von Willebrand factor (VWF) are two important angiogenic molecules that can drive pathologic angiogenesis and progression of liver fibrosis in our previous study. MicroRNAs (miRs) participate in a variety of physiological and pathological processes, including angiogenesis. However, the critical miRs targeting Angpt1 or VWF and potential molecular mechanism underlying liver fibrosis-associated angiogenesis is not clear yet. Human liver tissues were obtained from patients with different chronic liver diseases. Mouse models of liver fibrosis were induced by injection of CCl(4) or bile duct ligation (BDL) operation. MiR-671-5p was predicted to target Angpt1 and VWF from three databases (miRanda, RNA22v2, and miRwalk). MiR-671-5p expression was decreased in the fibrotic liver of human and mice, with a negative correlation with the levels of Angpt1, VWF, sphingosine kinase-1 (SphK1, the rate-limiting enzyme for sphingosine 1-phosphate [S1P] formation), transforming growth factor β1 (TGFβ1), hypoxia inducible factor (Hif)1α, Hif2α, and fibrosis markers. Importantly, miR-671-5p expression was down-regulated in fluorescence-activated cell sorted liver sinusoidal endothelial cells and hepatic stellate cells (HSCs) in CCl(4) mice compared with control mice. In vitro miR-671-5p expression was also decreased in S1P-stimulated HSCs and TGFβ1-activated liver sinusoidal endothelial cells, negatively correlated with Angpt1 and VWF expression. MiR-671-5p directly targeted Angpt1 and VWF by luciferase reporter assays. In vivo administration of miR-671-5p agomir decreased the messenger RNA and protein levels of Anpgt1 and VWF, and attenuated CCl(4) -induced or BDL-induced liver angiogenesis and fibrosis. Conclusion: We identify the negative regulation of miR-671-5p on Angpt1 and VWF and liver fibrosis-associated angiogenesis, which may provide promising targets for the prevention and treatment of liver disease.