Berberine attenuates liver fibrosis by autophagy inhibition triggering apoptosis via the miR-30a-5p/ATG5 axis

Abstract

Berberine (BBR) is an effective drug against liver fibrosis (LF). Autophagy is involved in the pathogenesis of LF; however, the mechanism linking BBR to autophagy in LF remains unresolved. To explore the underlying mechanism, we assessed the effects of BBR on autophagy and apoptosis of activated hepatic stellate cells (HSCs) in vitro and in a murine model of fibrosis. The decreased expression of the autophagy activation marker ATG5, autophagosome formation, and autophagy flux in the HSC model confirmed that BBR inhibited autophagy in activated HSCs and in mice with liver fibrosis. Moreover, ATG5 was necessary for inducing autophagy and HSC activation. BBR suppressed ATG5 expression by upregulating miR-30a-5p expression, which affected the stability of ATG5 mRNA by binding to its 3′-untranslated region, an effect that was attenuated by treatment with a miR-30a-5p inhibitor. BBR also markedly induced HSC apoptosis, as indicated by the upregulated expression of the pro-apoptosis markers p53, BAX, and cleaved PARP and the downregulated expression of the anti-apoptosis marker BCL-2, effects that were reversed by ATG5 overexpression. In vivo, BBR improved mouse LF by decreasing collagen deposition, inflammatory cell infiltration, and expression of fibrosis markers hydroxyproline, α-smooth muscle actin, and collagen type 1-A1 and the autophagy marker LC3. BBR had a protective effect on mouse fibrotic livers and reduced serum aspartate aminotransferase and alanine aminotransferase levels. Collectively, these results reveal a novel mechanism of BBR-induced autophagy inhibition triggering apoptosis in HSCs, providing a reliable experimental and theoretical basis for developing BBR-based candidate drugs for LF.