Adipose-derived mesenchymal stem cells inhibit JNK-mediated mitochondrial retrograde pathway to alleviate acetaminophen-induced acute liver injury

Acetaminophen (APAP) is the major cause of drug-induced liver injury, with limited treatment options. APAP overdose invokes excessive oxidative stress that triggers mitochondria-to-nucleus retrograde pathways, contributing to APAP-induced liver injury (AILI). Mesenchymal stem cell therapy is a promising tool for acute liver failure. Therefore, the purpose of this study is to investigate the beneficial effects of adipose-derived mesenchymal stem cell (AMSC) therapy on AILI and reveal the potential therapeutic mechanisms. C57BL/6 mice are used as the animal model and AML12 normal murine hepatocytes as the cellular model of APAP overdose. Immunohistochemical staining, western blotting, immunofluorescence staining, and RNA sequencing assay are used for assessing the efficacy and validating mechanisms of AMSC therapy. We found AMSC therapy effectively ameliorated AILI, while delayed AMSC injection lost its efficacy related to the c-Jun N-terminal kinase (JNK)-mediated mitochondrial retrograde pathways. We further found that AMSC therapy inhibited JNK activation and mitochondrial translocation, reducing APAP-induced mitochondrial damage. The down-regulation of activated Ataxia telangiectasia mutated (ATM) and DNA damage response proteins in AMSC treated mice liver indicated AMSC blocked the JNK-ATM pathway. Overall, AMSC may be an effective treatment for AILI by inhibiting JNK-ATM mitochondrial retrograde pathway, which improves APAP-induced mitochondrial dysfunction and liver injury. Comparative gene expression profiling analysis of RNA-seq data for NC, APAP overdosed-mice and AMSC-treated mice.