MOTS-c Protects Against Acetaminophen-induced Liver Injury through the MAPK Signaling Pathway

OBJECTIVE: Acetaminophen (APAP)-induced liver injury (AILI) is a leading cause of acute liver failure worldwide, but effective therapeutic strategies are still lacking. MOTS-c, a mitochondrial-derived peptide, has demonstrated hepatoprotective properties in models of nonalcoholic steatohepatitis (NASH) and hepatitis B virus (HBV) infection. This study aims to explore the role and underlying mechanisms of MOTS-c in AILI. METHODS: An AILI model was established in male C57BL/6 mice via intraperitoneal (i.p.) injection of APAP (300 mg/kg). The therapeutic potential of MOTS-c and its mechanisms were assessed using behavioral tests, qPCR, western blotting, ELISA, immunohistochemistry, immunofluorescence, and TUNEL staining. RESULTS: MOTS-c levels in both plasma and liver tissues were significantly reduced in APAPinduced AILI mice compared with controls. Administration of MOTS-c via i.p. injection markedly attenuated APAP-induced increases in AST and ALT levels, histopathological liver damage, and other liver injury markers. MOTS-c treatment suppressed the release of pro-inflammatory factors (TNF-α, IL-1β, IL-6, and COX-2) and macrophage infiltration induced by APAP. Furthermore, MOTS-c treatment significantly restored GSH content, diminished reactive oxygen species (ROS) production, and oxidative stress. TUNEL staining confirmed that increased apoptosis in APAPtreated livers was significantly attenuated by MOTS-c, which are key contributors to hepatocyte death and liver injury. Mechanistic studies revealed that MOTS-c inhibited APAP-induced phosphorylation of MAPK pathway components, including ERK, JNK, and p38. The protective effects of MOTS-c on serum ALT and AST levels were abolished by co-treatment with inhibitors of ERK, JNK, and p38. DISCUSSION: This study reveals that the mitochondrial peptide MOTS-c can alleviate drug-induced liver injury by suppressing oxidative stress and inflammation via the MAPK pathway. This positions MOTS-c as a promising therapeutic candidate for treating APAP-induced liver injury. CONCLUSION: This study demonstrates that administering MOTS-c effectively protects against APAP-induced liver injury in mice. The protective mechanism involves suppressing the damaging MAPK signaling pathway (ERK, JNK, p38), which in turn reduces oxidative stress, inflammation, and cell death.