Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global health concern, with limited effective treatments. KCNMA1 potassium channel has been implicated in the pathogenesis of various metabolic diseases. However, whether and how KCNMA1 regulates MASLD have been elusive.

Global, hepatic stellate cells (HSCs)-specific, and hepatocyte-specific Kcnma1 knockout mice were fed either a standard chow or a high-fat diet (HFD). Serum and liver tissues were collected and analyzed by biochemical assay, histology, qPCR and western blotting. HSCs conditioned medium (CM) treatment hepatocytes experiment model and three-dimensional (3D) hepatocytes-HSCs spheroids were employed to study lipid accumulation in hepatocytes. A Cytokine Antibody Array was used to analyze the cytokine profile.

Our study demonstrated that global Kcnma1 deletion prevented diet-induced hepatic steatosis and improved insulin sensitivity. Further analyses using HSC-specific and hepatocyte-specific Kcnma1 knockout MASLD mouse models revealed that the protective effect against hepatic steatosis was predominantly mediated by Kcnma1 deletion in HSCs, rather than in hepatocytes. CM transfer experiment and 3D spheroid studies show Kcnma1 deletion effectively prevents lipid accumulation in hepatocytes. Mechanically, Kcnma1-deficient HSCs secrete Amphiregulin (AREG) to regulate lipid metabolism in hepatocytes via epidermal growth factor receptor (EGFR) signaling. Of clinical significance, AREG levels were notably reduced in the liver tissue of MASLD patients, while injection of recombinant AREG protein significantly ameliorated MASLD in mice.

Our study uncovers a novel mechanism in which Kcnma1 deletion in HSCs enhances AREG secretion, thereby reducing lipid accumulation in hepatocytes through the AREG/EGFR signaling, ultimately inhibiting the progression of MASLD.