Interplay of Placental DNA Methylation and Maternal Insulin Sensitivity in Pregnancy

Diabetes. 2020 Mar;69(3):484-492. doi: 10.2337/db19-0798. Epub 2019 Dec 27.

Abstract

The placenta participates in maternal insulin sensitivity changes during pregnancy; however, mechanisms remain unclear. We investigated associations between maternal insulin sensitivity and placental DNA methylation markers across the genome. We analyzed data from 430 mother-offspring dyads in the Gen3G cohort. All women underwent 75-g oral glucose tolerance tests at ∼26 weeks of gestation; we used glucose and insulin measures to estimate insulin sensitivity (Matsuda index). At delivery, we collected samples from placenta (fetal side) and measured DNA methylation using Illumina EPIC arrays. Using linear regression models to quantify associations at 720,077 cytosine-guanine dinucleotides (CpGs), with adjustment for maternal age, gravidity, smoking, BMI, child sex, and gestational age at delivery, we identified 188 CpG sites where placental DNA methylation was associated with Matsuda index (P < 6.94 × 10-8). Among genes annotated to these 188 CpGs, we found enrichment in targets for miRNAs, in histone modifications, and in parent-of-origin DNA methylation including the H19/MIR675 locus (paternally imprinted). We identified 12 known placenta imprinted genes, including KCNQ1 Mendelian randomization analyses revealed five loci where placenta DNA methylation may causally influence maternal insulin sensitivity, including the maternally imprinted gene DLGAP2. Our results suggest that placental DNA methylation is fundamentally linked to the regulation of maternal insulin sensitivity in pregnancy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Birth Weight
  • Blood Glucose / metabolism*
  • CpG Islands
  • DNA Methylation*
  • Diabetes, Gestational / genetics*
  • Diabetes, Gestational / metabolism
  • Female
  • Genomic Imprinting
  • Glucose Tolerance Test
  • Humans
  • Infant, Newborn
  • Insulin / metabolism*
  • Insulin Resistance / genetics*
  • KCNQ1 Potassium Channel / genetics
  • Linear Models
  • Male
  • Mendelian Randomization Analysis
  • MicroRNAs / genetics
  • Nerve Tissue Proteins / genetics
  • Placenta / metabolism*
  • Pregnancy / metabolism*
  • RNA, Long Noncoding / genetics

Substances

  • Blood Glucose
  • DLGAP2 protein, human
  • H19 long non-coding RNA
  • Insulin
  • KCNQ1 Potassium Channel
  • KCNQ1 protein, human
  • MIRN675 microRNA, human
  • MicroRNAs
  • Nerve Tissue Proteins
  • RNA, Long Noncoding