GalNAc-conjugated siRNA targeting C/EBPβ reverses metabolic dysfunction and restores liver homeostasis in a murine MASLD model.

CCAAT/enhancer-binding protein beta (C/EBPβ) is a master regulator of hepatic metabolism, inflammation, and fibrosis, making it an attractive but underexploited target for metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we demonstrate that GalNAc-conjugated small interfering RNA (siRNA) targeting C/EBPβ (GalNAc-siCEBPβ) significantly improves liver function and metabolic parameters in a high fat diet (HFD) murine model. In vitro, GalNAc-siCEBPβ achieved dose-dependent C/EBPβ mRNA silencing (∼80% knockdown at 0.1 μM) in primary mouse hepatocytes. In vivo, subcutaneous administration (10 mg/kg) reduced hepatic C/EBPβ expression by 45% (p < 0.01), concomitant with a marked reduction in liver steatosis and improved metabolic profile (15% less weight gain, 20% lower glucose, 25% reduced triglycerides), and restored liver function (18% higher albumin, 22% lower bilirubin)-all without hepatotoxicity (ALT/AST unchanged). Notably, these effects occurred despite continued HFD feeding, suggesting disease-modifying potential. By leveraging the precision of RNAi and hepatocyte-specific GalNAc delivery, GalNAc-siCEBPβ addresses key limitations of current MASLD therapies by targeting both metabolism and fibrosis. Our findings support clinical translation for MASLD and its complications, including hepatocellular carcinoma.