Placental microRNAs relate to early childhood growth trajectories

Maternal exercise programs placental miR-495-5p-mediated Snx7 expression and kynurenic acid metabolic pathway induced by prenatal high-fat diet: Based on miRNA-seq, transcriptomics, and metabolomics

Poor intrauterine environments increase the prevalence of chronic metabolic diseases in offspring, whereas maternal exercise is an effective measure to break this vicious intergenerational cycle. Placenta is increasingly being studied to explore its role in maternal-fetal metabolic cross-talk. The association between placental miRNA and offspring development trajectories has been established, yet the specific role and mechanism thereof in maternal exercise-induced metabolic protection remain elusive. Here, C57BL/6 female mice were subjected to either a normal control or a high-fat diet (HFD), half of the HFD-fed dams were housed with voluntary wheel running for 3 weeks before and during gestation. At embryonic day 18.5, we sacrificed parturient mice and then conducted miRNA-seq, transcriptomic, and metabolomic profiling of the placenta. Our data revealed that maternal HFD resulted in significant alterations in both miRNA and gene expressions, as well as metabolic pathways of the placenta, whereas prenatal exercise negated these perturbations. The common differentially expressed transcripts among three groups were enriched in multiple critical pathways involving energy expenditure, signal transduction, and fetal development. Through integrated analysis of multiomics data, we speculated that maternal exercise reversed the suppression of miR-495-5p induced by HFD, thereby inhibiting miR-495-5p-targeted Snx7 and modulating kynurenic acid production. These datasets provided novel mechanistic insight into how maternal exercise positively affects the metabolic homeostasis of offspring. The discovered important miRNAs, mRNAs, and metabolites could be promising predictive and therapeutic targets for protecting offspring metabolic health.

Implications for miR-339-5p regulation of trophoblast proliferation and migration in placentas associated with porcine intrauterine growth retardation using integrated transcriptome sequencing analysis

Placental dysfunction is considered as one of the main etiologies of fetal intrauterine growth retardation (IUGR). MicroRNAs (miRNAs) have been demonstrated to be a vital epigenetic modification involved in regulating the placental function and pregnancy outcomes in mammals. However, the mechanisms underlying placenta-specific miRNAs involved in the occurrence and development of pig IUGR remain unclear. In this work, we compared the placental morphologies of piglets with IUGR and normal birth weight (NBW) by using histomorphological analysis and performed a miRNA-mRNA integrative analysis of the gene expression profiles of IUGR and NBW placentas through RNA sequencing. We also investigated the role of differentially expressed ssc-miR-339-5p/GRIK3 through an in vitro experiment on porcine trophoblast cells (PTr2). IUGR piglets had significantly lower birth weight, placental weight, placental efficiency, and placental villus and capillary densities compared with the NBW piglets (P < 0.05). A total of 81 differentially expressed miRNAs and 726 differentially expressed genes in the placentas were screened out between the IUGR and NBW groups. The miRNA-mRNA interaction networks revealed the key core miRNA (ssc-miR-339-5p) and its corresponding target genes. Subsequently, we found that upregulation of ssc-miR-339-5p significantly inhibited the migration and proliferation of PTr2 cells (P < 0.05). The dual-luciferase reporter system showed that GRIK3 was the target gene of ssc-miR-339-5p, and the transcription level of GRIK3 may be negatively regulated by ssc-miR-339-5p. Additionally, overexpression of ssc-miR-339-5p significantly increased (P < 0.05) the mRNA expression levels of genes involved in the cytokine-cytokine receptor interaction pathway. These results indicate that ssc-miR-339-5p may affect the migration and proliferation of trophoblast cells by regulating the expression of GRIK3 and altering the placental inflammatory response, resulting in a suboptimal morphology and function of the placenta and the development of pig IUGR.

Dilemma of Epigenetic Changes Causing or Reducing Metabolic Disorders in Offsprings of Obese Mothers

Maternal obesity is associated with fetal complications predisposing later to the development of metabolic syndrome during childhood and adult stages. High-fat diet seems to influence individuals and their subsequent generations in mediating weight gain, insulin resistance, obesity, high cholesterol, diabetes, and cardiovascular disorder. Research evidence strongly suggests that epigenetic alteration is the major contributor to the development of metabolic syndrome through DNA methylation, histone modifications, and microRNA expression. In this review, we have discussed the outcome of recent studies on the adverse and beneficial effects of nutrients and vitamins through epigenetics during pregnancy. We have further discussed about the miRNAs altered during maternal obesity. Identification of new epigenetic modifiers such as mesenchymal stem cells condition media (MSCs-CM)/exosomes for accelerating the reversal of epigenetic abnormalities for the development of new treatments is yet another aspect of the present review.