Sodium butyrate supplementation inhibits hepatic steatosis by stimulating liver kinase B1 and insulin-induced gene.

BACKGROUND AND AIMS: Butyric acid is an intestinal microbiota-produced short-chain fatty acid, which exerts salutary effects on alleviating nonalcoholic fatty liver disease (NAFLD). However, the underlying mechanism of butyrate on regulating hepatic lipid metabolism is largely unexplored.

METHODS: A mouse model of NAFLD was induced with HFD feeding, and sodium butyrate (NaB) intervention was initiated at the 8th week and lasted for eight weeks. Hepatic steatosis was evaluated and metabolic pathways concerning lipid homeostasis were analyzed.

RESULTS: Here, we report that administration of NaB by gavage once daily for eight-weeks causes an augmentation of insulin-induced gene (Insig) activity and inhibition of lipogenic gene in mice fed with high-fat diet. Mechanistically, NaB is sufficient to enhance the interaction between Insig and its upstream kinase AMPK. The stimulatory effects of NaB on Insig-1 activity are abolished in AMPKα1/α2 double knockout (AMPK-/-) mouse primary hepatocytes. Moreover, AMPK activation by NaB is mediated by LKB1 as evidenced by the observations showing NaB-mediated induction of phosphorylation of AMPK and its downstream target ACC is diminished in LKB1-/- mouse embryonic fibroblasts.

CONCLUSIONS: These studies indicate that NaB serves as a negative regulator of hepatic lipogenesis in NAFLD and that NaB attenuates hepatic steatosis, improves lipid profile and liver function largely through the activation of LKB1-AMPK-Insig signaling pathway. Therefore, NaB has therapeutic potential for treating NAFLD and related metabolic diseases.