Betaine rescue of an animal model with methylenetetrahydrofolate reductase deficiency.
Biochem J
; 382(Pt 3): 831-40, 2004 Sep 15.
Article
en En
| MEDLINE
| ID: mdl-15217352
MTHFR (methylenetetrahydrofolate reductase) catalyses the synthesis of 5-methyltetrahydrofolate, the folate derivative utilized in homocysteine remethylation to methionine. A severe deficiency of MTHFR results in hyperhomocysteinaemia and homocystinuria. Betaine supplementation has proven effective in ameliorating the biochemical abnormalities and the clinical course in patients with this deficiency. Mice with a complete knockout of MTHFR serve as a good animal model for homocystinuria; early postnatal death of these mice is common, as with some neonates with low residual MTHFR activity. We attempted to rescue Mthfr-/- mice from postnatal death by betaine supplementation to their mothers throughout pregnancy and lactation. Betaine decreased the mortality of Mthfr-/- mice from 83% to 26% and significantly improved somatic development from postnatal day 1, compared with Mthfr-/- mice from unsupplemented dams. Biochemical evaluations demonstrated higher availability of betaine in suckling pups, decreased accumulation of homocysteine, and decreased flux through the trans-sulphuration pathway in liver and brain of Mthfr-/- pups from betaine-supplemented dams. We observed disturbances in proliferation and differentiation in the cerebellum and hippocampus in the knockout mice; these changes were ameliorated by betaine supplementation. The dramatic effects of betaine on survival and growth, and the partial reversibility of the biochemical and developmental anomalies in the brains of MTHFR-deficient mice, emphasize an important role for choline and betaine depletion in the pathogenesis of homocystinuria due to MTHFR deficiency.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Betaína
/
Metilenotetrahidrofolato Reductasa (NADPH2)
/
Homocistinuria
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Biochem J
Año:
2004
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Reino Unido