Deletion of the neural tube defect-associated gene Mthfd1l disrupts one-carbon and central energy metabolism in mouse embryos.

Autor:	Bryant JD; From the Departments of Molecular Biosciences and., Sweeney SR; Nutritional Sciences and the Dell Pediatric Research Institute, The University of Texas at Austin, Austin, Texas 78712., Sentandreu E; Nutritional Sciences and the Dell Pediatric Research Institute, The University of Texas at Austin, Austin, Texas 78712., Shin M; From the Departments of Molecular Biosciences and., Ipas H; From the Departments of Molecular Biosciences and., Xhemalce B; From the Departments of Molecular Biosciences and., Momb J; From the Departments of Molecular Biosciences and., Tiziani S; Nutritional Sciences and the Dell Pediatric Research Institute, The University of Texas at Austin, Austin, Texas 78712., Appling DR; From the Departments of Molecular Biosciences and dappling@austin.utexas.edu.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2018 Apr 20; Vol. 293 (16), pp. 5821-5833. Date of Electronic Publication: 2018 Feb 26.
DOI:	10.1074/jbc.RA118.002180
Abstrakt:	One-carbon (1C) metabolism is a universal folate-dependent pathway essential for de novo purine and thymidylate synthesis, amino acid interconversion, universal methyl-donor production, and regeneration of redox cofactors. Homozygous deletion of the 1C pathway gene Mthfd1l encoding methylenetetrahydrofolate dehydrogenase (NADP + -dependent) 1-like, which catalyzes mitochondrial formate production from 10-formyltetrahydrofolate, results in 100% penetrant embryonic neural tube defects (NTDs), underscoring the central role of mitochondrially derived formate in embryonic development and providing a mechanistic link between folate and NTDs. However, the specific metabolic processes that are perturbed by Mthfd1l deletion are not known. Here, we performed untargeted metabolomics on whole Mthfd1l -null and wildtype mouse embryos in combination with isotope tracer analysis in mouse embryonic fibroblast (MEF) cell lines to identify Mthfd1l deletion-induced disruptions in 1C metabolism, glycolysis, and the TCA cycle. We found that maternal formate supplementation largely corrects these disruptions in Mthfd1l- null embryos. Serine tracer experiments revealed that Mthfd1l- null MEFs have altered methionine synthesis, indicating that Mthfd1l deletion impairs the methyl cycle. Supplementation of Mthfd1l -null MEFs with formate, hypoxanthine, or combined hypoxanthine and thymidine restored their growth to wildtype levels. Thymidine addition alone was ineffective, suggesting a purine synthesis defect in Mthfd1l- null MEFs. Tracer experiments also revealed lower proportions of labeled hypoxanthine and inosine monophosphate in Mthfd1l- null than in wildtype MEFs, suggesting that Mthfd1l deletion results in increased reliance on the purine salvage pathway. These results indicate that disruptions of mitochondrial 1C metabolism have wide-ranging consequences for many metabolic processes, including those that may not directly interact with 1C metabolism. (© 2018 Bryant et al.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu