Measuring acetyl-CoA and acetylated histone turnover in vivo: Effect of a high fat diet.

Cellular availability of acetyl-CoA, a central intermediate of metabolism, regulates histone acetylation. The impact of a high-fat diet (HFD) on the turnover rates of acetyl-CoA and acetylated histones is unknown. We developed a method for simultaneous measurement of acetyl-CoA and acetylated histones kinetics using a single HO tracer, and used it to examine effect of HFD-induced perturbations on hepatic histone acetylation in LDLR mice, a mouse model of non-alcoholic fatty liver disease (NAFLD). Mice were given HO in the drinking water and the kinetics of hepatic acetyl-CoA, histones, and acetylated histones were quantified based on their H-labeling. Consumption of a high fat Western-diet (WD) for twelve weeks led to decreased acetylation of hepatic histones (p< 0.05), as compared to a control diet. These changes were associated with 1.5-3-fold increased turnover rates of histones without any change in acetyl-CoA flux. Acetylation significantly reduced the stability of histones and the turnover rates of acetylated peptides were correlated with the number of acetyl groups in neighboring lysine sites. We conclude that HO-method can be used to study metabolically controlled histone acetylation and acetylated histone turnover in vivo.