Inhibition of micro RNA ‐214 ameliorates hepatic fibrosis and tumor incidence in platelet‐derived growth factor C transgenic mice

Differentially regulated micro RNA (mi RNA ) are associated with hepatic fibrosis; however, their potential usefulness for blocking hepatic fibrosis has not been exploited fully. We examined the expression of mi RNA in the liver of a transgenic mouse model in which platelet‐derived growth factor C ( PDGF ‐C) is overexpressed ( Pdgf‐c Tg ), resulting in hepatic fibrosis and steatosis and the eventual development of hepatocellular carcinoma ( HCC ). Robust induction of miR‐214 correlated with fibrogenesis in the liver of Pdgf‐c Tg mice, atherogenic high‐fat diet‐induced NASH mice, and patients with chronic hepatitis B or C. Pdgf‐c Tg mice were injected with locked nucleic acid ( LNA )‐antimiR‐214 via the tail vein using Invivofectamine 2.0 and the degree of hepatic fibrosis and tumor incidence were evaluated. Pdgf‐c Tg mice treated with LNA ‐antimiR‐214 showed a marked reduction in fibrosis and tumor incidence compared with saline or LNA ‐miR‐control‐injected control mice. In vitro , LNA ‐antimiR‐214 significantly ameliorated TGF ‐β1‐induced pro‐fibrotic gene expression in Lx‐2 cells. MiR‐214 targets a negative regulator of EGFR signaling, Mig‐6. Mimic‐miR‐214 decreased the expression of Mig‐6 and increased the levels of EGF ‐mediated p‐ EGFR (Y1173 and Y845) and p‐Met (Tyr1234/1235) in Huh‐7 cells. Conversely, LNA ‐antimiR‐214 repressed the expression of these genes. In conclusion, miR‐214 appears to participate in the development of hepatic fibrosis by modulating the EGFR and TGF ‐β signaling pathways. LNA ‐antimiR‐214 is a potential therapy for the prevention of hepatic fibrosis.