The role of H3K9 acetylation and gene expression in different brain regions of Alzheimer's disease patients.

Aims: To evaluate H3K9 acetylation and gene expression profiles in three brain regions of Alzheimer's disease (AD) patients and elderly controls, and to identify AD region-specific abnormalities. Methods: Brain samples of auditory cortex, hippocampus and cerebellum from AD patients and controls underwent chromatin immunoprecipitation sequencing, RNA sequencing and network analyses. Results: We found a hyperacetylation of AD cerebellum and a slight hypoacetylation of AD hippocampus. The transcriptome revealed differentially expressed genes in the hippocampus and auditory cortex. Network analysis revealed Rho GTPase-mediated mechanisms. Conclusions: These findings suggest that some crucial mechanisms, such as Rho GTPase activity and cytoskeletal organization, are differentially dysregulated in brain regions of AD patients at the epigenetic and transcriptomic levels, and might contribute toward future research on AD pathogenesis.

Alzheimer's disease (AD) is the most common form of dementia affecting the elderly population. The onset and progression of AD are influenced by environmental factors, which are able to promote epigenetic changes on the DNA and/or the DNA-associated proteins called histones. We investigated a specific epigenetic modification of histones (H3K9 acetylation) in three brain regions of AD patients and compared them with elderly controls. We found increased levels of H3K9 acetylation in the cerebellum of AD patients, as well as a slight decrease of this modification in the hippocampus of the same patients. These brain tissues from AD patients showed abnormal gene expression patterns when compared with elderly controls. These findings contribute to understanding the molecular changes that occur in AD, and provide a basis for future research or drug development for AD treatment.

Role of histone acetylation in gastric cancer: implications of dietetic compounds and clinical perspectives.

Histone modifications regulate the structural status of chromatin and thereby influence the transcriptional status of genes. These processes are controlled by the recruitment of different enzymes to a specific genomic site. Furthermore, obtaining an understanding of these mechanisms could help delineate alternative treatment and preventive strategies for cancer. For example, in gastric cancer, cholecalciferol, curcumin, resveratrol, quercetin, garcinol and sodium butyrate are natural regulators of acetylation and deacetylation enzyme activity that exert chemopreventive and anticancer effects. Here, we review the recent findings on histone acetylation in gastric cancer and discuss the effects of nutrients and bioactive compounds on histone acetylation and their potential role in the prevention and treatment of this type of cancer.