Plain Language Summary
Mouse study establishing that MOTS-c levels are reduced in acetaminophen-induced liver injury (AILI) and that exogenous MOTS-c exerts hepatoprotection through the MAPK signaling pathway, reducing hepatocyte necrosis and oxidative stress in APAP-overdose mice. Extends MOTS-c's known hepatoprotective profile to acute drug-induced liver failure. Provides mechanistic evidence for MOTS-c as an emergency hepatoprotective intervention in APAP toxicity—the leading cause of acute liver failure—through MAPK pathway modulation, offering a novel mitochondrial peptide-based therapeutic target for drug-induced liver injury.
Abstract
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.
Authors
Li, Nan; Xu, Yimin; Chen, Qixin; Jiang, Jinhong; Li, Wei Wei