MicroRNA changes, activation of progenitor cells and severity of liver injury in mice induced by choline and folate deficiency

Dietary deficiency in methyl-group donors and cofactors induces liver injury that resembles many pathophysiological and histopathological features of human nonalcoholic fatty liver disease (NAFLD), including an altered expression of microRNAs (miRNAs). We evaluated the consequences of a choline- and folate-deficient (CFD) diet on the expression of miRNAs in the livers of male A/J and WSB/EiJ mice. The results demonstrate that NAFLD-like liver injury induced by the CFD diet in A/J and WSB/EiJ mice was associated with marked alterations in hepatic miRNAome profiles, with the magnitude of miRNA expression changes being greater in WSB/EiJ mice, the strain characterized by the greatest severity of liver injury. Specifically, WSB/EiJ mice exhibited more prominent changes in the expression of common miRNAs as compared to A/J mice and distinct miRNA alterations, including the overexpression of miR-134, miR-409-3p, miR-410 and miR-495 miRNAs that were accompanied by an activation of hepatic progenitor cells and fibrogenesis. This in vivo finding was further confirmed by in vitro experiments showing an overexpression of these miRNAs in undifferentiated progenitor hepatic HepaRG cells compared to in fully differentiated HepaRG cells. Additionally, a marked elevation of miR-134, miR-409-3p, miR-410 and miR-495 was found in plasma of WSB/EiJ mice fed the CFD diet, while none of the miRNAs was changed in plasma of A/J mice. These findings suggest that miRNAs may be crucial regulators responsible for the progression of NAFLD and may be useful as noninvasive diagnostic indicators of the severity and progression of NAFLD.