ABSTRACT: Metabolic dysfunction-associated steatotic liver disease (MASLD/MASH) is a progressive hepatic disorder driven primarily by aberrant glycolytic reprogramming in hepatocytes. Fructose-1,6-bisphosphatase 1 (FBP1), a rate-limiting enzyme of gluconeogenesis, is critically involved in diverse metabolic disorders; however, its functional role and regulatory mechanism underlying MASLD/MASH progression remain poorly understood. Pyruvate kinase M2 (PKM2), a key glycolytic enzyme, has emerged as a promising therapeutic target for MASLD/MASH. Here, using clinical specimens, diet-induced murine MASLD/MASH models, and hepatocyte cell lines, we demonstrate consistent downregulation of FBP1 during the transition from MASLD to MASH. Mechanistically, FBP1 directly interacts with PKM2, ENO1, and LDHA to govern the spatial compartmentalization of glycolytic enzyme complexes. FBP1 binding suppresses PKM2 enzymatic activity and restricts excessive hepatic glycolysis, thereby ameliorating intracellular lipid accumulation. Molecular docking and domain mapping further defined the precise binding regions between FBP1 and PKM2, and disruption of their interaction largely abrogated the glycolysis-repressive effects of FBP1. In vivo functional validation confirmed that wild-type FBP1, but not its binding-deficient mutant FBP1 G260R-Δ5, effectively alleviates hepatic steatosis, inflammation, and fibrosis in MASLD/MASH mice. Collectively, this study reveals a previously unrecognized non-canonical function of FBP1 in orchestrating glycolytic complex compartmentalization, establishes a critical molecular crosstalk linking hepatic gluconeogenesis and glycolysis, and provides a novel actionable target for MASLD/MASH therapeutic intervention.
Lei Fang 
