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

Background & Aims: Liver fibrosis and its end-stage form cirrhosis contribute to millions of deaths annually. The lack of robust antifibrotic molecules is in part attributed to the absence of any functional screens to identify molecular regulators using patient- derived primary human hepatic myofibroblasts, which are key drivers of fibrosis. Methods: Here, 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). Results: We identified miR-190b-5p and miR-296-3p as robust antifibrotic miRNAs that suppress liver fibrosis. Notably, the expression of miR-190b-5p and miR-296-3p was found to be 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 antifibrotic properties of miR-190b-5p and miR-296-3p are, at least in part, dependent on HAS2 and ITGA6. Finally, we showed the antifibrotic function of both miRNAs in a human liver bud model, which mimics multiple features of the human liver. Conclusions: Collectively, in our study we discovered miR-190b-5p and miR-296-3p as two novel antifibrotic 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 fibrosis. (c) 2024 The Authors. Published by Elsevier B.V. on behalf of European Association for the Study of the Liver. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).