Project description:Post-translational acetylation of proteins at lysine side chains by the central metabolite acetyl-CoA, is a crucial regulator of proteostasis. Ethanol metabolism in the liver induces protein acetylation and disrupts hepatic substrate metabolism. While acetylation can influence gene transcription, enzyme activity, and stability of proteins, the role of ethanol-induced acetylation in hepatic metabolism is still unclear. We used a 2H2O-based metabolic labeling approach to investigate the impact of ethanol-induced acetylation on liver metabolism in a murine model of chronic ethanol-induced liver injury. Mice were fed an ethanol containing diet for 25 days; liver proteins and acetylation patterns were monitored during the final 21 days of 2H2O labeling. The proteome, acetylome, and targeted metabolic profiling were conducted to evaluate ethanol-induced alterations in hepatic metabolism. Ethanol consumption induced hepatic steatosis, inflammation, and oxidative stress. It led to reduced turnover of mitochondrial proteins and increased turnover of cytosolic stress response proteins and metabolic enzymes. Ethanol elevated acetylation levels of mitochondrial metabolic enzymes and nuclear histones, with no significant changes in the cytosol. Acetylation stabilized mitochondrial proteins but destabilized histones. Ethanol-induced reduced mitochondrial protein turnover, linked to increased acetylation, led to hepatic protein accumulation. Impaired proteasomal and lysosomal degradation contributed to alcohol-induced hepatic proteopathy. These changes were associated with altered levels of acyl-CoAs and acyl-carnitines, amino acids, and tricarboxylic acid (TCA) cycle intermediates, reflecting impaired fatty acid oxidation, nitrogen disposal and citric acid cycle activities. In conclusion, ethanol-induced alterations in acetylome dynamics could modify hepatic substrate metabolism and contribute to liver injury in alcohol-associated liver disease through acetylation-dependent epigenetic changes and the regulation of metabolic enzymes.