Selenium and its' role in the maintenance of genomic stability.

摘要: Selenium (Se) is an essential micronutrient for humans, acting as a component of the unusual amino acids, selenocysteine (Se-Cys) and selenomethionine (Se-Met). Where Se levels are low, cell cannot synthesise selenoproteins, although some selenoproteins tissues prioritised over others. Characterised functions known include selenium transport (selenoprotein P), antioxidant/redox properties (glutathione peroxidases (GPxs), thioredoxin reductases selenoprotein P) anti-inflammatory S GPx4). Various forms consumed part normal diet, or dietary supplement. Supplementation tissue culture media, animal human diets with moderate certain compounds may protect against formation DNA adducts, chromosome breakage, gain loss. Protective effects have also been shown on mitochondrial DNA, telomere length function. Some gene expression relate to modulation methylation inhibition histone deacetylation. Despite large number positive in various model systems, there now clinical trials that adverse supplementation, according endpoints. Too much harmful too little, models showing "U"-shaped efficacy curve. Current recommended daily allowances differ among countries, but generally based amount necessary saturate GPx enzymes. However, increasing evidence suggests other enzymes be more important than action, optimal depend upon form being ingested, vary genotype. New paradigms, possibly involving nutrigenomic tools, will optimise desirable maximum protection genomic stability all humans.