Gpbar1 agonism promotes a Pgc-1α-dependent browning of white adipose tissue and energy expenditure and reverses diet-induced steatohepatitis in mice

Gpbar1 is a bile acid activated receptor for secondary bile acids. Here we have investigated the mechanistic role of Gpbar1 in the regulation of adipose tissues functionality in a murine model of steatohepatitis (NASH). Feeding wild type and Gpbar1(-/-) mice with a high fat diet-fructose (HFD-F) lead to development of NASH-like features. Treating HFD-F mice with 6 beta-ethyl-3a, 7b-dihydroxy-5b-cholan-24-ol (BAR501), a selective Gpbar1-ligand, reversed insulin resistance and histologic features of NASH, increased the weight of epWAT and BAT functionality and promoted energy expenditure and the browning of epWAT as assessed by measuring expression of Ucp1 and Pgc-1 alpha. The beneficial effects of BAR501 were lost in Gpbar1(-/-) mice. In vitro, BAR501 promoted the browning of 3T3-L1 cells a preadipocyte cell line and recruitment of CREB to the promoter of Pgc-1a. In conclusion, Gpbar1 agonism ameliorates liver histology in a rodent model of NASH and promotes the browning of white adipose tissue.