Regulation of hepatic fibrosis by Carcinoembryonic Antigen-related Cell Adhesion Molecule 1.

OBJECTIVE: NAFLD is a complex disease marked by cellular abnormalities leading to NASH. NAFLD patients manifest low hepatic levels of CEACAM1, a promoter of insulin clearance. Consistently, Cc1-/- null mice displayed spontaneous hyperinsulinemia/insulin resistance and steatohepatitis. Liver-specific reconstitution of Ceacam1 reversed these metabolic anomalies in 8-month-old Cc1-/-xliver+ mice fed a regular chow diet. The current study examined whether it would also reverse progressive hepatic fibrosis in mice fed a high-fat (HF) diet.

METHODS: 3-month-old mice were fed a high-fat diet for 3-5 months, and metabolic and histopathological analysis were conducted to evaluate their NASH phenotype.

RESULTS: Reconstituting CEACAM1 to Cc1-/- livers curbed diet-induced liver dysfunction and NASH, including macrovesicular steatosis, lobular inflammation, apoptosis, oxidative stress, and chicken-wire bridging fibrosis. Persistence of hepatic fibrosis in HF-fed Cc1-/- treated with nicotinic acid demonstrated a limited role for lipolysis and adipokine release in hepatic fibrosis caused by Ceacam1 deletion.

CONCLUSIONS: Restored metabolic and histopathological phenotype of HF-fed Cc1-/-xliver+ assigned a critical role for hepatic CEACAM1 in preventing NAFLD/NASH including progressive hepatic fibrosis.