Knockdown of circ_0044226 promotes endoplasmic reticulum stress-mediated autophagy and apoptosis in hepatic stellate cells via miR-4677-3p/SEC61G axis.

ABSTRACT

Downregulation of circ_0044226 has been demonstrated to reduce pulmonary fibrosis, but the role of circ_0044226 in liver fibrosis remains to be explored. In this work, we found that circ_0044226 expression was upregulated during liver fibrosis. Knockdown of circ_0044226 inhibited proliferation, promoted autophagy and apoptosis of hepatic stellate cell LX-2. Bioinformatic analysis and dual luciferase reporter assays confirmed the interaction between circ_0044226, miR-4677-3p and SEC61G. Mechanistically, knockdown of circ_0044226 suppressed SEC61G expression by releasing miR-4677-3p, thereby enhancing endoplasmic reticulum stress. Overexpression of SEC61G or endoplasmic reticulum stress inhibitor 4-phenylbutiric acid partially reversed the effect of knockdown circ_0044226 on LX-2 cell function. In vivo experiments showed that inhibition of circ_0044226 attenuated CCL4-induced liver fibrosis in mice. These imply that circ_0044226 may be a potential target for the treatment of liver fibrosis.