Sestrin2 protects against acetaminophen-induced liver injury.

Acetaminophen (APAP) overdose accounts for half of the cases of acute liver failure worldwide. We previously reported that Sestrin2 (Sesn2) protects against d-galactosamine/lipopolysaccharide-induced acute fulminant liver failure. In this study, we demonstrated that Sesn2 protects APAP-induced liver injury in mice, using a recombinant adenovirus encoding Sesn2 (Ad-Sesn2). First, we found that treatment of mice with toxic levels of APAP significantly reduced Sesn2 expression. Tail-vein injection with Ad-Sesn2 inhibited APAP-induced serum alanine aminotransferase and aspartate aminotransferase levels and markedly reduced hepatocyte degeneration and inflammatory cell infiltration. Additionally, APAP-induced glutathione depletion and reactive oxygen species generation were inhibited by Ad-Sesn2 treatment. Consistently, hepatic inflammatory gene expression and proinflammatory cytokine levels were also inhibited in Sesn2-infected mice, and we observed reduced APAP-mediated apoptotic signaling by terminal transferase-mediated dUTP nick-end labeling staining of the hepatic tissue. At a high dose of APAP, the mortality rate of Ad-Sesn2-infected mice was significantly lower than that of control mice. Furthermore, Sesn2 prevented APAP-induced damage through suppression of downstream mitogen-activated protein kinase pathway activation. Therefore, Sesn2 exerted a protective effect against APAP-induced acute liver damage by inhibiting oxidative stress and proinflammatory signaling.