p53 attenuates acetaminophen-induced hepatotoxicity by regulating drug-metabolizing enzymes and transporter expression.

Acetaminophen (APAP) overdose is the most frequent cause of drug-induced acute liver failure. Inhibition of APAP metabolic activation and promotion in APAP disposition are important to protect against APAP-induced liver injury. Tumor suppressor p53 is traditionally recognized as a surveillance molecule to preserve genome integrity. Recent studies have emerged on discovering its functions in metabolic regulation. Our previous study reported that p53 promoted bile acid disposition and alleviated cholestastic syndrome. Here, we examined the effect of doxorubicin (Dox)-mediated p53 activation on APAP-induced hepatotoxicity in mice and revealed a novel role of p53 in regulating APAP metabolism and disposition. Histopathological and biochemical assessments demonstrated that administration of Dox (10 mg/kg/d) before APAP treatment (400 mg/kg) significantly alleviated APAP-induced hepatotoxicity. Dox treatment prevented APAP-induced GSH depletion and lipid peroxidation. p53-null mice were more susceptible to APAP-induced liver injury. Further, we found that the expression of drug-metabolizing enzymes and transporters CYPs, SULTs and MRPs was regulated by p53. Dox treatment also promoted Nrf2 activation and increased the expression of Nrf2 target genes including GSTα/μ and NQO1, which contribute to APAP detoxification. Overall, this study is the first to demonstrate the protective role of p53 in regulating APAP metabolism and disposition, which provides a potential new therapeutic target for APAP-induced liver injury.