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. <i>In vitro</i>, GalNAc-siCEBPβ achieved dose-dependent C/EBPβ mRNA silencing (∼80% knockdown at 0.1 μM) in primary mouse hepatocytes. <i>In vivo</i>, subcutaneous administration (10 mg/kg) reduced hepatic C/EBPβ expression by 45% (<i>p</i> < 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.