The natural product-derived JM-9 alleviates high-fat diet-induced fatty liver in mice by targeting MD2

Metabolic dysfunction-associated steatotic liver disease (MASLD), is gradually emerging as one of the most prevalent liver diseases worldwide. Previous research demonstrated the involvement of myeloid differentiation factor 2 (MD2), a co-receptor of TLR4, as a key mediator in MASLD pathogenesis. The current study identifies JM-9 as a novel MD2 inhibitor, and focuses on evaluating its potential therapeutic effects in mitigating MASLD progression.

Drug affinity responsive target stability (DARTS) assay and surface plasmon resonance assay were utilized to evaluate the MD2-targeting specificity of JM-9. In vitro, hepatocytes and macrophages were stimulated with palmitic acid (PA) followed by JM-9 treatment. In vivo, a high-fat diet (HFD)-induced MASLD model was established and subjected to JM-9 administration during the last 2 months.

JM-9 directly bound the Phe76 residue of MD2 to disrupt the PA-induced MD2/TLR4 complex formation, thus further restoring AMPK phosphorylation and inhibiting NF-κB activation to reducing lipid accumulation and inflammation, respectively. In the HFD-mediated MASLD mouse model, JM-9 alleviated the binding between MD2 and TLR4 in the liver and counteracted hepatic TBK1 and p65 activation and AMPK suppression, thereby mitigating liver inflammation, steatosis, and fibrosis.

JM-9, as a novel MD2 inhibitor, holds potential as a viable treatment option for MASLD by playing a dual role in regulating both lipid metabolism and inflammation response.