Transcriptomic and epigenetic changes in the hypothalamus are involved in an increased susceptibility to a high-fat-sucrose diet in prenatally stressed female rats

Association of weight regain with specific methylation levels in the NPY and POMC promoters in leukocytes of obese men: a translational study

Specific methylation of appetite-related genes in leukocytes could serve as a useful biomarker to predict weight regain after an energy restriction program. We aimed to evaluate whether the pre-intervention DNA methylation patterns involved in the epigenetic control of appetite-regulatory genes in leukocytes are associated with the weight regain process. Eighteen men who lost ≥5% of body weight after an 8-week nutritional intervention were categorized as "regainers" (≥10% weight regain) and "non-regainers" (<10% weight regain) 32weeks after stopping dieting. At baseline, leukocytes were isolated and DNA was analyzed for epigenetic methylation patterns of appetite-related gene promoters by MALDI-TOF mass spectrometry. Regainers showed higher methylation levels than non-regainers in proopiomelanocortin (POMC) CpG sites +136bp and +138bp (fold change from non-regainers=26%; p=0.020) and lower methylation of the whole analyzed region of neuropeptide Y (NPY; fold change from non-regainers=-22%; p=0.033), as well as of several individual NPY-promoter CpG sites. Importantly, total baseline NPY methylation was associated with weight-loss regain (r=-0.76; p<0.001), baseline plasma ghrelin levels (r=0.60; p=0.011) and leptin/ghrelin ratio (r=-0.52; p=0.046). Lower methylation levels of POMC CpG sites +136bp and +138bp were associated with success in weight-loss maintenance (odds ratio=0.042 [95% CI 0.01-0.57]; p=0.018), whereas lower total methylation levels in NPY promoter were associated with higher risk of weight regain (odds ratio=14.0 [95% CI 1.13-172]; p=0.039). Therefore, the study of leukocyte methylation levels reflects a putative epigenetic regulation of NPY and POMC, which might be implicated in the weight regain process and be used as biomarkers for predicting weight regain after dieting.

Impact of stress and stress physiology during pregnancy on child metabolic function and obesity risk

PURPOSE OF REVIEW

To summarize recent conceptual frameworks and empirical findings addressing the role of prenatal stress and stress biology in the context of fetal programming of metabolic function and obesity risk.

RECENT FINDINGS

The link between stress exposure and adverse health outcomes is well established. Growing evidence from animal and human studies now suggests that the experience of severe stress or perturbations in stress-related immune and endocrine processes during pregnancy may also impact the developing fetus to produce increased susceptibility for childhood and adult obesity, and dysregulated glycemic control.

SUMMARY

Because endocrine and immune ligands commonly associated with stress play an essential role during intrauterine development in cellular growth and differentiation perturbations in these systems during pregnancy are likely to produce alterations of structure and function of the brain and peripheral physiological systems in the offspring. To systematically study the effects of intrauterine stress exposure on child metabolic function and obesity risk, a multilevel approach is required that includes molecular and cellular studies, the use of animal models, and human observational and interventional studies. Such studies will set the stage for translational research to inform the subsequent development of diagnostic and primary or secondary intervention strategies in at-risk individuals.

Shifting to a control diet after a high-fat, high-sucrose diet intake induces epigenetic changes in retroperitoneal adipocytes of Wistar rats

The aim of the study was to analyze the phenotypic and epigenetic changes induced by the shift to a chow diet after an obesogenic environment. Animals were randomized to fed chow (control group) or high-fat-sucrose diet (HFS). After 10 weeks, half of the rats fed with HFS diet were reassigned to a chow diet (rest group) while the other half continued with the obesogenic diet (HFS group) until week 20. Changes in fat content, biochemical profile, and DNA methylation levels of several gene promoters from retroperitoneal adipocytes were analyzed. HFS diet intake for 10 weeks induced obese phenotype in the animals, increasing body weight and fat content. These effects were maintained until the end of the trial in HFS group, where an increase in liver fat content, a modification of lipid profile, and retroperitoneal adipose tissue hypertrophy were also observed. Changing the dietary pattern reversed these parameters. Epigenetic analysis showed that HFS diet intake for 20 weeks hypermethylated several CpG sites (6.7 and 29.30) and hypomethylated CpG site 15 from leptin gene promoter. Moreover, the obesogenic diet also hypomethylated CpG site 1 from Fasn (fatty acid synthase) gene promoter, without changes on Ppargc1a (peroxisome proliferator-activated receptor gamma coactivator 1-alpha), Srebf1 (sterol regulatory element-binding transcription factor 1), and aquaporin 7. Shifting to a chow diet reverted HFS-induced DNA methylation levels of some CpG sites of leptin promoter. Changing the dietary pattern hypomethylated a CpG site of Srebf1 and hypermethylated other CpGs on Ppargc1a and Fasn promoter. This study shed light on the reversibility of phenotypical and epigenetic changes induced by a HFS diet intake.