Identification and functional validation of miR-190b-5p and miR-296-3p as novel therapeutic attenuators of liver fibrosis

Highlights•Our study discovers miR-190b-5p and miR-296-3p as two novel anti-fibrotic small RNAs.•miR-190b-5p and miR-296-3p regulates the expression of HAS2 and ITGA6, which contribute to the mechanism underlying the miR-190b-5p and miR-296-3p-mediated suppression of liver fibrosis.•Our experiments on human liver bud model provide indications that miR-190b-5p and miR-296-3p may have therapeutic potential for mitigation of liver fibrosis.AbstractBackground & AimsLiver fibrosis and its end-stage form known as cirrhosis contributes to millions of deaths annually. The lack of robust anti-fibrotic molecules is in part attributed to absence of any functional screens to identify molecular regulators using patient-derived primary human hepatic myofibroblasts, which are key drivers of fibrosis.MethodsHere, to identify robust regulators of fibrosis, we performed functional microRNA screenings in primary human hepatic myofibroblasts followed by in vivo validation in three independent mouse models of fibrosis (toxin, cholestasis and MASH).ResultsWe identified miR-190b-5p and miR-296-3p as robust anti-fibrotic miRNAs that suppress liver fibrosis. Notably, the expression of miR-190b-5p and miR-296-3p was found significantly reduced in human livers with fibrosis. Mechanistically, we discovered hyaluronan synthase 2 (HAS2) and integrin alpha-6 (ITGA6) as novel targets of miR-190b-5p and miR-296-3p, respectively. Furthermore, we demonstrated that the anti-fibrotic properties of miR-190b-5p and miR-296-3p are, at least in part, dependent on HAS2 and ITGA6. Finally, we showed the anti-fibrotic function of both miRNAs in a human liver bud model, which mimics multiple features of human liver.ConclusionsCollectively, in our study we discovered miR-190b-5p and miR-296-3p as two novel anti-fibrotic miRNAs, and that HAS2 and ITGA6 contribute to miR-190b-5p- and miR-296-3p-mediated inhibition of liver fibrosis. These results provide a foundation for future research to explore the clinical utility of miR-190b-5p and miR-296-3p in liver injuries with fibrosis.Impact and ImplicationsLiver fibrosis and cirrhosis contribute to millions of deaths world-wide and, till date, remain as unmet medical needs. In this study, we discovered two microRNAs, miR-190b-5p and miR-296-3p, which suppress liver fibrosis in preclinical mouse models and a human liver bud model. Our promising results encourage further studies that aim to develop both miRNAs for the treatment of liver fibrosis in patients.Graphical abstractAAV vector-mediated delivery of miR-190b-5p or miR-296-3p preferentially in myofibroblasts results in the mitigation of periportal and pericentral liver fibrosis, due to modulation of HAS2 and ITGA6, respectively.