Exosomes Derived From Bone Marrow Macrophages of HFD-Fed Mice Regulating AKT/GSK Pathway in Hepatocytes via...

A high-fat diet (HFD) induces lipid accumulation and macrophage infiltration in the liver. M1-polarized macrophages promote hepatocyte insulin resistance, with exosomes mediating macrophage-hepatocyte crosstalk. This study investigates the mechanisms underlying macrophage-mediated remote regulation of the AKT/GSK pathway and glycogenesis in hepatocytes. Exosomes from mouse primary Bone Marrow-derived macrophages (BMMs) and RAW264.7 cells were isolated via ultracentrifugation. PKH26 labeling confirmed the uptake of macrophage-derived exosomes by hepatocytes. HEP1-6 cells were treated with supernatant or exosomes from BMMs of HFD-fed mice, and AKT/GSK pathway activity and glycogen synthesis were assessed. HFD-fed mice exhibited significant hepatic macrophage infiltration alongside elevated mRNA levels of M1-polarization markers, including Tnf-α, Il-6, and Mcp-1, in both liver tissues and BMMs. Exposure of HEP1-6 hepatocytes to conditioned media or exosomes isolated from BMMs of HFD-fed mice markedly suppressed AKT/GSK pathway activity and impaired glycogen synthesis. The levels of miR-222-5p were increased in exosomes derived from BMMs of HFD-fed mice. Exosome-delivering miR-222-5p impaired AKT/GSK pathway activity and glycogen synthesis in HEP1-6 cells via targeting PTK6. Furthermore, intravenous administration of exosomes from PA-treated RAW264.7 macrophages recapitulated insulin resistance phenotypes in the livers of HFD-fed mice. Exosomes derived from BMMs of HFD-fed mice deliver miR-222-5p to hepatocytes, regulating AKT/GSK pathway activity and glycogen synthesis through targeting PTK6. This study offers novel insights into the prevention and treatment of MAFLD by elucidating the role of macrophage-hepatocyte communication.