Metabolic dysfunction-associated steatotic liver disease (MASLD) and sarcopenia frequently coexist, yet their causal relationship and underlying mechanisms remain poorly defined. This study aimed to investigate whether a bidirectional causal link exists between MASLD and sarcopenia and to identify the molecular mediators involved in liver-muscle crosstalk.
Methods
We applied Mendelian randomization to test the causal effect of sarcopenia-related traits on MASLD risk. To capture distinct clinical features, we established complementary mouse models, including diet-induced and genetic (ob/ob) MASLD models, a stelic animal model, and a drug-induced muscle atrophy model. Multi-tissue transcriptomic profiling was performed on liver and muscle to uncover altered pathways.
Results
Complementing prior genetic evidence establishing MASLD as a causal factor for sarcopenia, our Mendelian randomization analysis revealed that diminished muscle mass and muscle function contribute to an elevated risk of MASLD. In mice with MASLD, we observed loss of muscle mass, reduced strength, and ectopic lipid deposition in skeletal muscle. Conversely, muscle atrophy exacerbated hepatic steatosis, inflammation, and fibrosis in MASLD mice. Transcriptional profiling revealed that sarcopenia impairs hepatic metabolic homeostasis by enhancing fatty acid uptake and impairing oxidative phosphorylation, while MASLD, in turn, promotes muscle dysfunction by exacerbating inflammatory responses and metabolic dysfunction. We further identified C-C motif chemokine ligand 2 as a key myokine that drives MASLD, and adrenomedullin as a key hepatokine that triggers sarcopenia.
Conclusions
By integrating MR analysis, complementary mouse models, and multi-tissue transcriptomics, we identified CCL2 and ADM as putative mediators of this inter-organ communication. These findings underscore the importance of viewing MASLD and sarcopenia as interconnected disorders, and targeting the hepatokine-myokine axis may break the vicious cycle that sustains both diseases. Future studies are needed to clarify the temporal sequence of sarcopenia onset and MASLD progression, and to further elucidate the downstream signaling pathways involving CCL2 and ADM.
Full text
https://www.xiahepublishing.com/2310-8819/JCTH-2025-00538
The study was recently published in the Journal of Clinical and Translational Hepatology .
The Journal of Clinical and Translational Hepatology (JCTH) is owned by the Second Affiliated Hospital of Chongqing Medical University and published by XIA & HE Publishing Inc. JCTH publishes high quality, peer reviewed studies in the translational and clinical human health sciences of liver diseases. JCTH has established high standards for publication of original research, which are characterized by a study's novelty, quality, and ethical conduct in the scientific process as well as in the communication of the research findings. Each issue includes articles by leading authorities on topics in hepatology that are germane to the most current challenges in the field. Special features include reports on the latest advances in drug development and technology that are relevant to liver diseases. Regular features of JCTH also include editorials, correspondences and invited commentaries on rapidly progressing areas in hepatology. All articles published by JCTH, both solicited and unsolicited, must pass our rigorous peer review process.
