Liver-specific deletion of Eva1a/Tmem166 aggravates acute liver injury by impairing autophagy

Abstract

Acute liver failure (ALF) is an inflammation-mediated hepatocellular injury process associated with cellular autophagy. However, the mechanism by which autophagy regulates ALF remains undefined. Herein, we demonstrated that Eva1a (eva-1 homolog A)/Tmem166 (transmembrane protein 166), an autophagy-related gene, can protect mice from ALF induced by d-galactosamine (D-GalN)/lipopolysaccharide (LPS) via autophagy. Our findings indicate that a hepatocyte-specific deletion of Eva1a aggravated hepatic injury in ALF mice, as evidenced by increased levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), myeloperoxidase (MPO), and inflammatory cytokines (e.g., TNFα and IL-6), which was associated with disordered liver architecture exhibited by Eva1a^−/− mouse livers with ALF. Moreover, we found that the decreased autophagy in Eva1a^−/− mouse liver resulted in the substantial accumulation of swollen mitochondria in ALF, resulting in a lack of ATP generation, and consequently hepatocyte apoptosis or death. The administration of Adeno-Associated Virus Eva1a (AAV-Eva1a) or antophagy-inducer rapamycin increased autophagy and provided protection against liver injury in Eva1a^−/− mice with ALF, suggesting that defective autophagy is a significant mechanism of ALF in mice. Collectively, for the first time, we have demonstrated that Eva1a-mediated autophagy ameliorated liver injury in mice with ALF by attenuating inflammatory responses and apoptosis, indicating a potential therapeutic application for ALF.