Placental microRNA Expression Is Not Altered by Maternal Obesity and Fetal Overgrowth

摘要

>Objective The epigenetic mechanisms underlying fetal metabolic programming are poorly understood. We studied whether obesity is associated with alterations in placental miRNA expression. >Study Design A cross-sectional study was performed, including (1) normal-weight women (BMI 20–24.9 kg/m²) and normal-birth-weight (BW) infants (2,700–3,500 g) (n = 20), (2) normal-weight and macrosomic infants (BW ≥ 4,000 g) (n = 10), (3) obese (BMI ≥ 35 kg/m²) and normal BW infants (n = 16), and (4) obese and macrosomic infants (n = 10). All had term deliveries (37–41 weeks) and normal glucose tolerance (1 hour GCT < 7.2 mmol/L [130 mg/dL]). The expression of 5,639 placental miRNAs was assessed using miRNA microarray. Differential miRNA expression was determined using two-way ANOVA and pairwise contrasts, with the Benjamini-Hochberg (BH) correction. MiRNAs with Z-scores ≥ 2 and false discovery rate (FDR) < 20% were considered significant. >Results Principal components analysis demonstrated similar global miRNA expression profiles among groups. Of 5,639 miRNAs, only 5 were significantly different between obese and controls, which were not validated by quantitative polymerase reaction. >Conclusion There was no difference in placental miRNA expression associated with obesity or overgrowth. Aberrant placental miRNA expression is an unlikely mechanism underlying fetal metabolic programming related to maternal obesity.