20.500.12556/RUL-133819 Folate insufficiency due to MTHFR deficiency is bypassed by 5-methyltetrahydrofolate Adequate levels of folates are essential for homeostasis of the organism, prevention of congenital malformations, and the salvage of predisposed disease states. They depend on genetic predisposition, and therefore, a pharmacogenetic approach to individualized supplementation or therapeutic intervention is necessary for an optimal outcome. The role of folates in vital cell processes was investigated by translational pharmacogenetics employing lymphoblastoid cell lines (LCLs). Depriving cells of folates led to reversible S-phase arrest. Since 5,10-methylenetetrahydrofolate reductase (MTHFR) is the key enzyme in the biosynthesis of an active folate form, we evaluated the relevance of polymorphisms in the MTHFR gene on intracellular levels of bioactive metabolite, the 5-methyltetrahydrofolate (5-Me-THF). LCLs (n = 35) were divided into low- and normal-MTHFR activity groups based on their genotype. They were cultured in the presence of folic acid (FA) or 5-Me-THF. Based on the cells' metabolic activity and intracellular 5-Me-THF levels, we conclude supplementation of FA is sufficient to maintain adequate folate level in the normal MTHFR activity group, while low MTHFR activity cells require 5-Me-THF to overcome the metabolic defects caused by polymorphisms in their MTHFR genes. This finding was supported by the determination of intracellular levels of 5-Me-THF in cell lysates by LC-MS/MS. FA supplementation resulted in a 2.5-fold increase in 5-Me-THF in cells with normal MTHFR activity, but there was no increase after FA supplementation in low MTHFR activity cells. However, when LCLs were exposed to 5-Me-THF, a 10-fold increase in intracellular levels of this metabolite was determined. These findings indicate that patients undergoing folate supplementation to counteract anti-folate therapies, or patients with increased folate demand, would benefit from pharmacogenetics-based therapy choices. MTHFR 5 10-methylenetetrahydrofolate reductase polymorphisms folate supplementation folic acid FA 5-methyl-tetrahydrofolate 5-Me-THF folna kislina folatni dodatki reduktaza 5 10-metilentetrahidrofolata MTHFR presnova folatov true false true Angleški jezik Slovenski jezik Članek v reviji 2021-12-16 10:57:54 2021-12-16 10:57:56 2025-08-08 13:20:41 0000-00-00 00:00:00 2020 0 0 18 str. iss. 9, art. 2836 Vol. 9 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 577:616-074:616-008.9 2077-0383 10.3390/jcm9092836 28803331 RAZ_Vidmar_Masa_2020.pdf RAZ_Vidmar_Masa_2020.pdf 1 FA1260491C1A18F584BAB801A8C7DF07 175149713fe1011e7d20ba9e5de1df47c8184c4f9870ddec0e87045174e3c0da 72841573-5e57-11ec-abdb-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=152170 https://www.mdpi.com/2077-0383/9/9/2836 1 aedbfb98-3f1b-11ed-9c94-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=162362 Fakulteta za farmacijo Medicinska fakulteta 0 0 0