Nutrient-driven histone acetylation underlies energy storage and mobilization

In natural settings, energy storage and mobilization maintain a dynamic balance in response to recurrent overfeeding and fasting. Imbalanced energy storage and mobilization lead to a variety of metabolic dysfunctions. However, whether the metabolic status directly couples with epigenetic modifications and transcriptional outputs remains unclear. Here, we aimed to investigate the epigenetic mechanism underlying this adaptive balance and observed that, in an overfeeding state, increased glucose availability is associated with enhanced histone acetylation coinciding with acetyl-CoA production in an acyl-CoA short-chain synthetase 2 (ACSS2)-dependent manner, contributing to energy storage (e.g., lipogenesis); in contrast, in the fasting state, elevated d-β-hydroxybutyrate levels are associated with altered histone acetylation distribution and transcriptional programs, supporting a metabolic shift from anabolism to catabolism, such as fatty acid oxidation. In both overfeeding and fasting states, acetylated lysines in the histone require BRD4 to recognize and initiate transcriptional regulation. Inhibition of BRD4 leads to context-dependent phenotypic effects: it ameliorates non-alcoholic fatty liver disease (NAFLD) pathology induced by a high-fat diet, while it exacerbates hepatic steatosis in fasted mice or mice fed a ketogenic diet. Thus, these findings highlights that epigenetic regulation of energy storage and mobilization is closely linked to the availability of glucose, and ketone bodies. Moreover, our study revealed that modulation of ACSS2-associated pathway may represent a potential strategy for treatment of metabolic diseases, such as NAFLD.