Circulating microRNAs overexpressed in macrosomia: an experimental and bioinformatic approach

Global DNA methylation and miR-126-3p expression in Mexican women with gestational diabetes mellitus: a pilot study

BACKGROUND

Gestational diabetes mellitus (GDM), a type of diabetes that occurs for the first time during pregnancy, may predispose the development of chronic degenerative diseases and metabolic alterations in mother and offspring. DNA methylation and microRNA (miRNA) expression are regulatory mechanisms of gene expression that may contribute to the pathogenesis of GDM. Therefore, we determined global DNA methylation and miR-126-3p expression levels in 8 and 7 Mexican women with and without GDM, respectively.

METHODS AND RESULTS

Global DNA methylation was assessed by measuring the percentage of 5-methylcytosine (5-mC) in placenta, umbilical cord, and plasma DNA samples, whereas miR-126-3p expression was quantified by real-time PCR using the 2-ΔCt method of the corresponding RNA samples. A significant increase in the percentage of 5-mC was detected in placenta samples from GDM patients compared to healthy women, while plasma samples showed a significant decrease. Conversely, miR-126-3p expression levels were significantly higher in plasma from the GDM group, while placenta and umbilical cord samples showed no significant differences across experimental groups. Furthermore, DNA methylation correlated significantly with glucose levels in placenta and plasma. Likewise, miR-126-3p expression correlated significantly with plasma glucose, in addition to maternal body mass index (BMI at first trimester).

CONCLUSION

The results indicate that GDM is associated with alterations in global DNA methylation levels and miR-126-3p expression in placenta and/or plasma, providing insights into future novel approaches to diagnose and/or prevent this pathology.

Non-coding RNAs: The link between maternal malnutrition and offspring metabolism

Early life nutrition is associated with the development and metabolism in later life, which is known as the Developmental Origin of Health and Diseases (DOHaD). Epigenetics have been proposed as an important explanation for this link between early life malnutrition and long-term diseases. Non-coding RNAs (ncRNAs) may play a role in this epigenetic programming. The expression of ncRNAs (such as long non-coding RNA H19, microRNA-122, and circular RNA-SETD2) was significantly altered in specific tissues of offspring exposed to maternal malnutrition. Changes in these downstream targets of ncRNAs lead to abnormal development and metabolism. This review aims to summarize the existing knowledge on ncRNAs linking the maternal nutrition condition and offspring metabolic diseases, such as obesity, type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD).

Childhood obesity and adverse cardiometabolic risk in large for gestational age infants and potential early preventive strategies: a narrative review

Accumulating evidence indicates that obesity and cardiometabolic risks become established early in life due to developmental programming and infants born as large for gestational age (LGA) are particularly at risk. This review summarizes the recent literature connecting LGA infants and early childhood obesity and cardiometabolic risk and explores potential preventive interventions in early infancy. With the rising obesity rates in women of childbearing age, the LGA birth rate is about 10%. Recent literature continues to support the higher rates of obesity in LGA infants. However, there is a knowledge gap for their lifetime risk for adverse cardiometabolic outcomes. Potential factors that may modify the risk in early infancy include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. The early postnatal period may be a critical window of opportunity for active interventions to mitigate or prevent obesity and potential adverse metabolic consequences in later life. A variety of promising candidate biomarkers for the early identification of metabolic alterations in LGA infants is also discussed. IMPACT: LGA infants are the greatest risk category for future obesity, especially if they experience rapid postnatal growth during infancy. Potential risk modifying secondary prevention strategies in early infancy in LGA infants include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. LGA infants may be potential low-hanging fruit targets for early preventive interventions in the fight against childhood obesity.

Fetal Growth and Intrauterine Epigenetic Programming of Obesity and Cardiometabolic Disease

Epidemiologic studies have shown an association between an adverse intrauterine environment (eg, exposure to malnutrition) and an increased risk of developing cardiometabolic disease in adulthood. These studies laid the foundation for the developmental origins of health and disease hypothesis, which states that limited nutrient supply to the fetus results in physiologic and metabolic adaptations that favor survival but result in unfavorable consequences in the offspring if there is excess nutrition after birth. This discrepancy in the pre- and postnatal milieus, perceived as stress by the offspring, may confer an increased risk of developing cardiometabolic disease later in life. Thus, early life exposures result in programming or changes in cellular memory that have effects on health throughout the life course. One of the mechanisms by which programming occurs is via epigenetic modifications of genes, processes that result in functionally relevant changes in genes (ie, gene expression) without an alteration in the genotype. In this review, we will describe how fetal exposures, including under- and overnutrition, affect neonatal and childhood growth and the future risk for cardiometabolic disease.