Deletion of the neural tube defect-associated gene Mthfd1l disrupts one-carbon and central energy metabolism in mouse embryos.
J Biol Chem
; 293(16): 5821-5833, 2018 04 20.
Article
em En
| MEDLINE
| ID: mdl-29483189
ABSTRACT
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.
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Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Deleção de Genes
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Regulação da Expressão Gênica no Desenvolvimento
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Metabolismo Energético
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Redes e Vias Metabólicas
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Formiato-Tetra-Hidrofolato Ligase
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Aminoidrolases
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Metilenotetra-Hidrofolato Desidrogenase (NADP)
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Mitocôndrias
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Complexos Multienzimáticos
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Defeitos do Tubo Neural
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2018
Tipo de documento:
Article