The depot-specific and essential roles of CBP/p300 in regulating adipose plasticity

Fat remodeling has been extensively explored through protein deacetylation, but not yet acetylation, as a viable therapeutic approach in the management of obesity and related metabolic disorders. Here, we investigated the functions of key acetyltransferases CBP/p300 in adipose remodeling and their physiological effects by generating adipose-specific deletion of CBP (Cbp-AKO), p300 (p300-AKO) and double-knockout (Cbp/p300-AKO) models. We demonstrated that Cbp-AKO exhibited marked brown remodeling of inguinal WAT (iWAT) but not epididymal WAT (eWAT) after cold exposure and that this pattern was exaggerated in diet-induced obesity (DIO). Despite this striking browning phenotype, loss of Cbp was insufficient to impact body weight or glucose tolerance. In contrast, ablation of p300 in adipose tissues had minimal effects on fat remodeling and adiposity. Surprisingly, double-knockout mice (Cbp/p300-AKO) developed severe lipodystrophy along with marked hepatic steatosis, hyperglycemia and hyperlipidemia. Furthermore, we demonstrated that pharmacological inhibition of Cbp and p300 activity suppressed adipogenesis. Collectively, these data suggest that (i) CBP, but not p300, has distinct functions in regulating fat remodeling and that this occurs in a depot-selective manner; (ii) brown remodeling occurs independently of the improvements in glucose metabolism and obesity and (iii) the combined roles of CBP and p300 are indispensable for normal adipose development.