DNA-Hypomethylation by Hyper-Homocysteinemia: A Biochemical Mechanism Responsible for some Human Diseases, Explained to the Internist - Abstract
Background: DNA-hypomethylation is an epigenetic process inducing several degenerative diseases and healthy aging too. Aim: In this review, we explained the mechanism responsible for DNA-hypomethylation and illustrated the main degenerative diseases depending from that. Methods: The process originates by an increased homocysteine (Hcy) serum levels, that impairs S-Adenosyl-Methionine/S-Adenosyl-Homocysteine ratio (SAM/SAH ratio), also named as methylation index. This inhibits the enzymes: methyl transferases and thus, DNA methylation. Results: The mechanisms originating from DNA-hypomethylation, as a cause of early and massive atherosclerosis, were illustrated in detail. Also mood depression, some degenerative brain’s diseases, as Alzheimer and Parkinson were significantly dependent on DNA-hypomethylation, even through these have a multifactorial origin. Some cancers and healthy aging even somehow have bound to DNA-hypomethylation. Conclusions: DNA-hypomethylation is a fundamental biological reaction, responsible for several human diseases and due to increased Hcy levels. But, vitamins B6-9-12 supplementation, even through reduces the increased Hcy concentration, seems unable to cancel this epigenetic change.