Influence of pre-pregnancy body mass index (p-BMI) and gestational weight gain (GWG) on DNA methylation and protein expression of obesogenic genes in umbilical vein

The associations among maternal gestational weight gain, cord blood DNA methylation, and offspring childhood high BMI

OBJECTIVE

The objective of this study was to explore the associations among maternal gestational weight gain (GWG), cord blood DNA methylation, and high BMI.

METHODS

Using the Illumina Infinium MethylationEPIC Bead Chip, GWG-related methylation sites were screened in 40 cord blood samples using a cohort design, and the association of these sites with children's BMI status at 3 years was examined. Sites simultaneously related to GWG and children's BMI were validated in an external dataset. The mediation effect of target differential methylation probes in the association between GWG and children's BMI was also explored.

RESULTS

We identified 66 GWG-related differential methylation probes in cord blood, and four sites, including cg09973771 (SNTG2), cg00254258 (PRDM16), cg02672830 (MCPH1), and cg15424377, were found to be associated with children's BMI at age 3 years. The mediating effect of cord blood DNA methylation was not detected in the association between GWG and children's high BMI status. Out of the four sites screened, methylation level of site cg09973771 (SNTG2) in peripheral blood showed nominal significant differences among children with different BMI statuses at age 3 years.

CONCLUSIONS

Maternal GWG and childhood BMI status at age 3 years were associated with newborn cord blood DNA methylation.

The Possible Roles of Glucosamine-6-Phosphate Deaminases in Ammonium Metabolism in Cancer

Nearly 5% of the glucose-6-phosphate (Glc6P) in cells is diverted into the hexosamine biosynthetic pathway (HBP) to synthesize glucosamine-6-phosphate (GlcN6P) and uridine diphosphate N-acetyl-glucosamine-6-phosphate (UDP-GlcN6P). Fructose-6-phosphate (Fru6P) is a common intermediary between glycolysis and the HBP. Changes in HBP regulation cause abnormal protein N-glycosylation and O-linked-N-acetylglucosamine modification (O-GlcNAcylation), affecting protein function and modifying cellular responses to signals. The HBP enzymes glucosamine-6-phosphate deaminases 1 and 2 (GNPDA1 and 2) turn GlcN6P back into Fru6P and ammonium, and have been implicated in cancer and metabolic diseases. Despite the plentiful literature on this topic, the mechanisms involved are just beginning to be studied. In this review, we summarize, for the first time, the current knowledge regarding the possible roles of the isoenzymes of both GNPDAs in the pathogenesis and development of metabolic diseases and cancer from a molecular point of view, highlighting their importance not only in supplying carbon from glycolysis, but also in ammonia metabolism.

Total Gestational Weight Gain Is Explained by Leptin and Body Fat, Regardless of Pre-Pregnancy Body Mass Index and Other Adipokines, in Mexican Adolescents

Pre-pregnancy body mass index (pBMI) is a predictor of gestational weight gain (GWG). However, other factors, such as adipokines and inflammation markers, may also be associated with GWG. The aim of the study was to determine the association of leptin, adiponectin, irisin, and C-reactive protein, with GWG in adolescents. A longitudinal study was conducted from 2018 to 2023 in adolescents with a clinically healthy pregnancy. The assessments included sociodemographic and clinical data, pBMI, percent of body fat, serum concentrations of leptin, adiponectin, irisin, and high-sensitivity C-reactive protein (hsCRP), and total GWG adequacy. Cox regression models were performed, the outcome variables were inadequate and excessive GWG. In 198 participants, being overweight/obesity was marginally associated with a protective effect against inadequate GWG (HR = 0.44, 95%CI = 0.18-1.06), regardless of maternal characteristics and adipokines. Leptin (HR = 1.014, 95%CI = 1.008-1.021), and body fat percent (HR = 1.11, 95%CI = 1.05-1.17) were associated with a higher risk of excessive GWG, independent of other maternal variables such as pBMI, while adiponectin was associated with a lower risk. These findings suggest that, in Mexican adolescents, adipose tissue and its adipokines during pregnancy may play a more significant role in the final GWG than body weight.

Serum Folate, Red Blood Cell Folate, and Zinc Serum Levels Are Related with Gestational Weight Gain and Offspring's Birth-Weight of Adolescent Mothers

BACKGROUND

Gestational weight gain below or above the Institute of Medicine recommendations has been associated with adverse perinatal and neonatal outcomes. Very few studies have evaluated the association between serum and red blood cell folate concentrations and gestational weight gain in adolescents. Additionally, zinc deficiency during pregnancy has been associated with impaired immunity, prolonged labor, preterm and post-term birth, intrauterine growth restriction, low birth weight, and pregnancy-induced hypertension.

OBJECTIVE

The purpose of our study is to evaluate the association between serum concentrations of zinc, serum folate, and red blood cell folate, with the increase in gestational weight and the weight and length of the newborn in a group of adolescent mothers from Mexico City.

RESULTS

In our study, 406 adolescent-neonate dyads participated. The adolescents' median age was 15.8 years old. The predominant socioeconomic level was middle-low (57.8%), single (57%), 89.9% were engaged in home activities, and 41.3% completed secondary education. Excessive gestational weight gain was observed in 36.7% of cases, while insufficient gestational weight gain was noted in 38.4%. Small for gestational age infants were observed in 20.9% of the sample. Low serum folate (OR 2.1, 95% CI 1.3-3.3), decreased red blood cell folate (OR 1.6, 95% CI 1.0-2.6), and reduced serum zinc concentrations (OR 3.3, 95% CI 2.1-5.2) were associated with insufficient gestational weight gain. Decreased serum zinc levels (OR 1.2, 95% CI 1.2-3.4) were linked to an increased probability of delivering a baby who is small for their gestational age.

CONCLUSIONS

Low serum folate, red blood cell folate, and serum zinc concentrations were associated with gestational weight gain and having a small gestational age baby. Both excessive and insufficient gestational weight gain, as well as having a small gestational age baby, are frequent among adolescent mothers.

Genetics and epigenetics in the obesity phenotyping scenario

Obesity is a common complex trait that elevates the risk for various diseases, including type 2 diabetes and cardiovascular disease. A combination of environmental and genetic factors influences the pathogenesis of obesity. Advances in genomic technologies have driven the identification of multiple genetic loci associated with this disease, ranging from studying severe onset cases to investigating common multifactorial polygenic forms. Additionally, findings from epigenetic analyses of modifications to the genome that do not involve changes to the underlying DNA sequence have emerged as key signatures in the development of obesity. Such modifications can mediate the effects of environmental factors, including diet and lifestyle, on gene expression and clinical presentation. This review outlines what is known about the genetic and epigenetic contributors to obesity susceptibility, along with the albeit limited therapeutic options currently available. Furthermore, we delineate the potential mechanisms of actions through which epigenetic changes can mediate environmental influences and the related opportunities they present for future interventions in the management of obesity.

Gestational Weight Gain Relates to DNA Methylation in Umbilical Cord, Which, In Turn, Associates with Offspring Obesity-Related Parameters

Excessive gestational weight gain (GWG) has a negative impact on offspring's health. Epigenetic modifications mediate these associations by causing changes in gene expression. We studied the association between GWG and DNA methylation in umbilical cord tissue; and determined whether the DNA methylation and the expression of corresponding annotated genes were associated with obesity-related parameters in offspring at 6 years of age. The methylated CpG sites (CpGs) associated with GWG were identified in umbilical cord tissue by genome-wide DNA methylation (n = 24). Twelve top CpGs were validated in a wider sample by pyrosequencing (n = 87), and the expression of their 5 annotated genes (SETD8, TMEM214, SLIT3, RPTOR, and HOXC8) was assessed by RT-PCR. Pyrosequencing results validated the association of SETD8, SLIT3, and RPTOR methylation with GWG and showed that higher levels of SETD8 and RPTOR methylation and lower levels of SLIT3 methylation relate to a higher risk of obesity in the offspring. The association of SETD8 and SLIT3 gene expression with offspring outcomes paralleled the association of methylation levels in opposite directions. Epigenetic changes in the umbilical cord tissue could explain, in part, the relationship between GWG and offspring obesity risk and be early biomarkers for the prevention of overweight and obesity in childhood.

Individual, Family, and Social Factors Associated with Gestational Weight Gain in Adolescents: A Scoping Review

About 56% to 84% of pregnant adolescents have inappropriate (insufficient or excessive) gestational weight gain (GWG); however, the factors associated with GWG in this age group have not been systematically identified. This scoping review aimed to synthesize the available scientific evidence on the association of individual, family, and social factors with inappropriate gestational weight gain in pregnant adolescents. To carry out this review, the MEDLINE, Scopus, Web of Science, and Google Scholar databases were searched for articles from recent years. The evidence was organized according to individual, family, and social factors. The analyzed studies included 1571 adolescents from six retrospective cohorts, 568 from three prospective cohorts, 165 from a case-control study, 395 from a cross-sectional study, and 78,001 from two national representative samples in the USA. At the individual level, in approximately half of the studies, the pre-pregnancy body mass index (pBMI) was positively associated with the GWG recommended by the Institute of Medicine of the USA (IOM). The evidence was insufficient for the other factors (maternal age, number of deliveries, and family support) to determine an association. According to the review, we concluded that pBMI was positively associated with the GWG. More quality studies are needed to assess the association between GWG and individual, family, and social factors.

Genetics, epigenetics and transgenerational transmission of obesity in children

Sedentary lifestyle and consumption of high-calorie foods have caused a relentless increase of overweight and obesity prevalence at all ages. Its presently epidemic proportion is disquieting due to the tight relationship of obesity with metabolic syndrome and several other comorbidities which do call for urgent workarounds. The usual ineffectiveness of present therapies and failure of prevention campaigns triggered overtime a number of research studies which have unveiled some relevant aspects of obesity genetic and epigenetic inheritable profiles. These findings are revealing extremely precious mainly to serve as a likely extra arrow to allow the clinician's bow to achieve still hitherto unmet preventive goals. Evidence now exists that maternal obesity/overnutrition during pregnancy and lactation convincingly appears associated with several disorders in the offspring independently of the transmission of a purely genetic predisposition. Even the pre-conception direct exposure of either father or mother gametes to environmental factors can reprogram the epigenetic architecture of cells. Such phenomena lie behind the transfer of the obesity susceptibility to future generations through a mechanism of epigenetic inheritance. Moreover, a growing number of studies suggests that several environmental factors such as maternal malnutrition, hypoxia, and exposure to excess hormones and endocrine disruptors during pregnancy and the early postnatal period may play critical roles in programming childhood adipose tissue and obesity. A deeper understanding of how inherited genetics and epigenetics may generate an obesogenic environment at pediatric age might strengthen our knowledge about pathogenetic mechanisms and improve the clinical management of patients. Therefore, in this narrative review, we attempt to provide a general overview of the contribution of heritable genetic and epigenetic patterns to the obesity susceptibility in children, placing a particular emphasis on the mother-child dyad.