Histones post-translational modifications associated with the development of metabolic dysfunction-associated fatty liver disease. Part 3. Histon acetylation

Based on the analysis of literature sources from the Pubmed, MEDLINE, The Cochrane Library, Embase databases, the authors of the article highlight general provisions regarding histone acetylation. They emphasize that it is acetylation of the lysine residue that is the key post-translational modification of histones by epigenetic mechanisms of gene expression regulation. To date, at least 2000 human proteins have been identified that can be modified at lysine residues by acetylation. About 1000 proteins in human liver tissue undergo modification by lysine acetylation. Acetylation is mediated by histone acetyltransferases (HAT/KAT) and is usually associated with active gene transcription due to its ability to decondense chromatin. In contrast, histone deacetylases (HDAC/KDAC) remove the acetyl group from the lysine residue of histones and, thus, restore the compact form of chromatin. The acetylation state of target sites is determined by the balance of activity between the processes of acetylation and deacetylation of the N-terminal regions of histone molecules. Histone hyperacetylation can be caused by both increased HAT/KAT activity and decreased HDAC expression. Histone acetyltransferases catalyze the transfer of an acetyl group from acetyl-CoA to the epsilon-amino group of lysine, neutralizing the positive charge of lysine and weakening the interaction between histones and the DNA molecule. Histone acetylation is always associated with chromatin opening and activation of gene transcription. The authors emphasize that an increase in the representation of acetylated markers is associated with the progression of metabolic dysfunction-associated fatty liver disease (MAFLD). A particularly high level of acetylation (hyperacetylation) in MAFLD is noted at sites K9, K14 and K18 of histone 3. Today, epigenetic mechanisms that determine the state of histone acetylation in the region of certain genes are considered as potential targets for drug treatment. Studying the influence of histone acetylation on morphological changes in tissue and the development of metabolic disorders is the basis that will allow developing effective epigenetic methods for treatment of patients with MAFLD.