Prenatal Exposure to Mercury: Associations with Global DNA Methylation and Hydroxymethylation in Cord Blood and in Childhood

Abstract Background Intrauterine growth restriction (IUGR) is associated with faltered growth and development later in life. Alteration in DNA methylation may occur among IUGR babies and it can have bearing on the outcome. Objectives To compare the DNA methylation in the cord blood among IUGR and appropriate for gestational age (AGA) babies and find it is association with their neurodevelopmental outcome at 18 months of age. Methodology Genomic DNA methylation among 40 IUGR and equal number of AGA neonates was estimated by using 5-mC ELISA kit in the cord blood. Infants were assessed at birth and their anthropometric measurements were taken. They were regularly followed up and assessed for neurodevelopment outcome till 18 months of age using DASII (Developmental Assessment Scale for Indian Infants). DNA methylation was correlated with neurodevelopmental outcome. Numbers and percentages were used for categorical data. Mean and SD were used for continuous variables. The significant mean difference between IUGR and AGA was determined by independent Student t-test. To study the association between the DNA methylation and outcome, Spearman correlation was used. A p < 0.05 was considered as statistically significant. Results Significant difference in DNA methylation was observed between IUGR and AGA infants (IUGR: 3.12 ± 1.24; AGA: 4.40 ± 2.03; p < 0.001). Anthropometry (weight, length and head circumference) at birth was significantly decreased among IUGR infants. Hospital stay was significantly longer for IUGR infants. Motor (IUGR: 89.98 ± 18.77; AGA: 101.75 ± 9.62; p < 0.001), and mental (IUGR: 90.81 ± 11.13; AGA: 105.71 ± 7.20; p < 0.001) scores were significantly decreased among IUGR compared with AGA neonates at 18 months of follow-up. Global DNA methylation had a significant positive correlation with mental score but not with motor developmental score. Conclusion IUGR babies had lower motor and mental score compared with AGA babies. Cord blood global DNA methylation significantly correlated with mental development score but not with motor development at 18 months of age.

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Association of Methylation-Related Nutrient Intake and Status with Offspring DNA Methylation in Pregnant Women with and Without Gestational Diabetes Mellitus

Current Developments in Nutrition ◽

10.1093/cdn/nzaa054_088 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 1016-1016

Author(s):

Xinyin Jiang ◽

Chauntelle Jack-Roberts ◽

Kaydine Edwards ◽

Ella Gilboa ◽

Ikhtiyor Djuraev ◽

...

Keyword(s):

Diabetes Mellitus ◽

Dna Methylation ◽

Gestational Diabetes ◽

Gestational Diabetes Mellitus ◽

Cord Blood ◽

Pregnant Women ◽

Nutrient Intake ◽

Blood Levels ◽

Global Dna Methylation ◽

Blood Samples

Abstract Objectives Gestational diabetes mellitus (GDM) is associated with alterations in DNA methylation in the placenta and offspring tissues. Nutrients participating in the methionine cycle (e.g., choline, betaine, folate, vitamin B12, methionine) influence the supply of methyl groups. The objective of this research was to determine whether maternal intake and status of these nutrients during pregnancy may interact with the GDM status to shape the offspring epigenome. Methods We conducted 3-day dietary recalls and collected blood samples from pregnant women with and without GDM (n = 22/group) to quantify methylation-related nutrient intakes and status. At delivery, we collected cord blood samples and measured global DNA methylation. Results GDM was associated with a 25% increase (P = 0.041) in global DNA methylation in the cord blood. Maternal choline intake (r = −0.602, P = 0.006) as well as cord blood methionine (r = −0.553, P = 0.014) and betaine (r = −0.566, P = 0.011) levels were negatively correlated with cord blood DNA methylation only in non-GDM women, while intakes and maternal blood levels of other methylation-related nutrients were not related to cord blood DNA methylation. Conclusions GDM and methyl nutrient intake/status interact to modify offspring DNA methylation in humans. Funding Sources Egg Nutrition Center.

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