miR-138/miR-222 Overexpression Characterizes the miRNome of Amniotic Mesenchymal Stem Cells in Obesity

Clinical findings and data obtained in animal models indicate that nutrient uptake and exposure to environmental agents during pregnancy may affect fetal/newborn gestational programming, thereby resulting in obesity and/or obesity-related disorders in offspring. Human amniotic mesenchymal stem cells (hA-MSCs) differentiate into adipocytes and are thus a suitable model to investigate adipocyte functions in obesity. The aim of this study was to elucidate the miRNome of hA-MSCs and its contribution to obesity in pregnancy. To this aim we used the following: (i) high-resolution small RNA sequencing to characterize the microRNA (miRNA) profiles of hA-MSCs of 13 obese (Ob-) and 7 control (Co-) pregnant women at delivery; (ii) multiple-method integrated bioinformatics to predict the metabolic pathways potentially miRNA deregulated in Ob-hA-MSCs; and (iii) microarray mRNA expression profiling to verify obese-associated mRNA alterations. In summary, 12 miRNAs were differentially expressed between Ob-hA-MSCs and Co-hA-MSCs, with a multiple-methods bioinformatic consensus on miR-138-5p and miR-222-3p, which were overexpressed in Ob-hA-MSCs versus Co-hA-MSCs. The top 20 significant pathways predicted to be deregulated through miR-138-5p and/or miR-222-3p/target interaction included fat cell differentiation and deposits, lipid/carbohydrate homeostasis, response to stress, metabolic syndrome, heart disease, and ischemia. In conclusion, our finding of miR-138-5p/miR-222-3p overexpression in Ob-hA-MSCs, together with the transcriptomic data, suggests that these miRNAs in obese pregnancy could derange metabolic pathways previously found impaired in tissues from obese adults or in obesity-associated disorders and concur to modify gestational programming as has been demonstrated in animal models. This raises the possibility of using diet-based strategies to normalize the perinatal miRNome in obesity.