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ABSTRACT: Context
An increase in maternal insulin resistance (IR) during pregnancy is essential for normal fetal growth. The mechanisms underlying this adaptation are poorly understood. Placental factors are believed to instigate and maintain these changes, as IR decreases shortly after delivery. Methylation of placental gene loci that are common targets for miRNAs are associated with maternal IR.Objective
We hypothesized that placental miRNAs targeting methylated loci are associated with maternal IR during late pregnancy.Methods
We collected placentas from 132 elective cesarean sections and fasting blood samples at delivery to estimate maternal homeostasis model assessment of insulin resistance (HOMA-IR). Placental miRNA expression was measured via whole genome small-RNA sequencing in a subset of 40 placentas selected by maternal pre-gravid body mass index (BMI) and neonatal adiposity. Five miRNAs correlated with maternal HOMA-IR and previously identified as targeting methylated genes were selected for validation in all 132 placenta samples via RT-qPCR. Multiple regression adjusted for relevant clinical variables.Results
Median maternal age was 27.5 years, with median pre-pregnancy BMI of 24.7 kg/m2, and median HOMA-IR of 2.9. Among the 5 selected miRNA, maternal HOMA-IR correlated with the placental expression of miRNA-371b-3p (r = 0.25; P = 0.008) and miRNA-3940-3p (r = 0.32; P = 0.0004) across the 132 individuals. After adjustment for confounding variables, placental miRNA-3940-3p expression remained significantly associated with HOMA-IR (β = 0.16; P = 0.03).Conclusion
Placental miRNA-3940-3p was associated with maternal IR at delivery. This placental miRNA may have an autocrine or paracrine effect-regulating placental genes involved in modulating maternal IR.
SUBMITTER: Alvarado-Flores F
PROVIDER: S-EPMC8787748 | biostudies-literature | 2021 Nov
REPOSITORIES: biostudies-literature
Alvarado-Flores Fernanda F Kaneko-Tarui Tomoko T Beyer William W Katz Jacqueline J Chu Tianjiao T Catalano Patrick P Sadovsky Yoel Y Hivert Marie-France MF O'Tierney-Ginn Perrie P
The Journal of clinical endocrinology and metabolism 20211101 12
<h4>Context</h4>An increase in maternal insulin resistance (IR) during pregnancy is essential for normal fetal growth. The mechanisms underlying this adaptation are poorly understood. Placental factors are believed to instigate and maintain these changes, as IR decreases shortly after delivery. Methylation of placental gene loci that are common targets for miRNAs are associated with maternal IR.<h4>Objective</h4>We hypothesized that placental miRNAs targeting methylated loci are associated with ...[more]