[Folate and homocysteine levels during pregnancy affect DNA methylation in human placenta].
OBJECTIVE
DNA methylation is one of the best characterized epigenetic mechanisms that play a regulatory role in genome programming and imprinting during embryogenesis. In this present study, we investigated the association between DNA methylation in the human placenta and the maternal folate and homocysteine concentrations on the Methylenetetrahydrofolatereductase (MTHFR) genetic polymorphism during pregnancy.


METHODS
We investigated 107 pregnant women who visited Ewha Woman's University Hospital for prenatal care during their 24-28 weeks-period of gestation. During the second trimester, we measured the serum homocysteine and folate concentrations. The MTHFR 677 genetic polymorphism was determine by performing PCR-RFLP assay. The expression of DNA methylation in the human placentas was estimated by using immunohistochemistry method.


RESULTS
Serum folate was negatively correlated with the serum homocysteine concentration for all the MTHFR genotypes. We found positive correlation between the folate concentrations and the DNA methylation in the human placenta (p<0.05). An increasing concentration of homocysteine was associated with reduced DNA methylation in the human placenta. The coefficient value was -2.03 (-3.77, -0.29) on the regression model (p<0.05).


CONCLUSIONS
These findings suggest that the maternal folate and homocysteine levels along with the MTHFR 677 genetic polymorphism during pregnancy affect the DNA methylation in the human placenta.
Park
Bo-hyun
BH
Department of Preventive Medicine, Ewha Womans University. hpark@ewha.ac.kr
Kim
Young-ju
YJ
Park
Jong-soon
JS
Lee
Hwa-young
HY
Ha
Eun-hee
EH
Min
Jung-won
JW
Park
Hye-sook
HS
D000328:Adult; D019175:DNA Methylation; D047108:Embryonic Development / Q000235:genetics; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007150:Immunohistochemistry; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D010920:Placenta; D012150:Polymorphism, Restriction Fragment Length; D011247:Pregnancy; D011262:Pregnancy Trimester, Second
D006710:Homocysteine; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)