Acetaminophen (
APAP) overdose can induce liver injury and is the most frequent cause of
acute liver failure in the United States. We investigated the role of p62/SQSTM1 (referred to as p62) in
APAP-induced liver injury (AILI) in mice. We found that the hepatic
protein levels of p62 dramatically increased at 24 h after
APAP treatment, which was inversely correlated with the hepatic levels of
APAP-adducts.
APAP also activated mTOR at 24 h, which is associated with increased cell proliferation. In contrast, p62 knockout (KO) mice showed increased hepatic levels of
APAP-adducts detected by a specific antibody using Western blot analysis but decreased mTOR activation and cell proliferation with aggravated liver injury at 24 h after
APAP treatment. Surprisingly, p62 KO mice recovered from AILI whereas the wild-type mice still sustained liver injury at 48 h. We found increased number of infiltrated macrophages in p62 KO mice that were accompanied with decreased hepatic
von Willebrand factor (VWF) and platelet aggregation, which are associated with increased cell proliferation and improved liver injury at 48 h after
APAP treatment. Our data indicate that p62 inhibits the late injury phase of AILI by increasing autophagic selective removal of
APAP-adducts and mitochondria but impairs the recovery phase of AILI likely by enhancing hepatic blood coagulation.