TY - JOUR
T1 - Importance of folate-homocysteine homeostasis during early embryonic development
AU - Taparia, Shveta
AU - Gelineau-Van Waes, Janée
AU - Rosenquist, Thomas H.
AU - Finnell, Richard H.
N1 - Funding Information:
The authors thank Ms. Michelle Merriweather and Ms. Margaret Yen from the Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology at Texas A&M Health Science Center for their assistance in this study. Dr. Shveta Taparia was supported by a Young Investigator Award (2005–2006) Fellowship from the Spina Bifida Association of America. This work was also supported in part by grants DE106315, HL66398, HL085859 and NS050249 from the National Institutes of Health.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - Although the beneficial effects of maternal folate supplementation in the periconceptional period have been shown to prevent neural tube defects, congenital heart defects and orofacial clefts, the exact protective mechanism of folates remains unknown. Folates affect DNA synthesis, amino acid metabolism and methylation of genes, proteins and lipids via S-adenosylmethionine-mediated one-carbon transfer reactions. Our laboratory has created several mouse knock out models of folate transport using gene targeting to inactivate folate receptor 1 (Folr1), folate receptor 2 (Folr2) and reduced folate carrier 1 (Slc19a1) genes. Gene ablation of both Folr1 and Slc19a1 leads to lethality, but with maternal folate supplementation, nullizygous embryos for both genes present with neural tube defects (NTDs) and congenital heart defects (CHDs). Folr1 nullizygous mice also exhibit orofacial clefts when the dams are provided with low folate supplementation during pregnancy. Finally, women with NTD-affected pregnancies have been reported to have high autoantibody titers against the folate receptor, potentially inhibiting the transport of folate to the developing embryo. This may be an explanation for some of the folate-responsive NTDs and perhaps other congenital malformations. Herein, we propose how homocysteinylation of the folate receptor may contribute to generation of these autoantibodies against the folate receptor.
AB - Although the beneficial effects of maternal folate supplementation in the periconceptional period have been shown to prevent neural tube defects, congenital heart defects and orofacial clefts, the exact protective mechanism of folates remains unknown. Folates affect DNA synthesis, amino acid metabolism and methylation of genes, proteins and lipids via S-adenosylmethionine-mediated one-carbon transfer reactions. Our laboratory has created several mouse knock out models of folate transport using gene targeting to inactivate folate receptor 1 (Folr1), folate receptor 2 (Folr2) and reduced folate carrier 1 (Slc19a1) genes. Gene ablation of both Folr1 and Slc19a1 leads to lethality, but with maternal folate supplementation, nullizygous embryos for both genes present with neural tube defects (NTDs) and congenital heart defects (CHDs). Folr1 nullizygous mice also exhibit orofacial clefts when the dams are provided with low folate supplementation during pregnancy. Finally, women with NTD-affected pregnancies have been reported to have high autoantibody titers against the folate receptor, potentially inhibiting the transport of folate to the developing embryo. This may be an explanation for some of the folate-responsive NTDs and perhaps other congenital malformations. Herein, we propose how homocysteinylation of the folate receptor may contribute to generation of these autoantibodies against the folate receptor.
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U2 - 10.1515/CCLM.2007.345
DO - 10.1515/CCLM.2007.345
M3 - Article
C2 - 18067451
AN - SCOPUS:36849064315
VL - 45
SP - 1717
EP - 1727
JO - Zeitschrift fur klinische Chemie und klinische Biochemie
JF - Zeitschrift fur klinische Chemie und klinische Biochemie
SN - 1434-6621
IS - 12
ER -