Prenatal glucocorticoid contributed to rat lung dysplasia is related to asymmetric dimethylarginine/nitric oxide pathway

Maternal Metformin Treatment Reprograms Maternal High-Fat Diet-Induced Hepatic Steatosis in Offspring Associated with Placental Glucose Transporter Modifications

Maternal high-fat (HF) diet exposure in utero may affect fetal development and cause metabolic problems throughout life due to lipid dysmetabolism and oxidative damage. Metformin has been suggested as a potential treatment for body weight reduction and nonalcoholic fatty liver disease, but its reprogramming effect on offspring is undetermined. This study assesses the effects of maternal metformin treatment on hepatic steatosis in offspring caused by maternal HF diet. Female rats were fed either a control or an HF diet before conception, with or without metformin treatment during gestation, and placenta and fetal liver tissues were collected. In another experiment, the offspring were fed a control diet until 120 d (adult stage). Metformin treatment during pregnancy ameliorates placental oxidative stress and enhances placental glucose transporter 1 (GLUT1), GLUT3, and GLUT4 expression levels through 5' adenosine monophosphate-activated protein kinase (AMPK) activation. Maternal metformin treatment was shown to reprogram maternal HF diet-induced changes in offspring fatty liver with the effects observed in adulthood as well. Further validation is required to develop maternal metformin therapy for clinical applications.

Obesity programmed by prenatal dexamethasone and postnatal high-fat diet leads to distinct alterations in nutrition sensory signals and circadian-clock genes in visceral adipose tissue

BACKGROUND

Prenatal dexamethasone treatment has been shown to enhance the susceptibility of offspring to postnatal high-fat (HF) diet-induced programmed obesity. We investigated the metabolic phenotypes, nutrient-sensing signal and circadian-clock genes in adipose tissue that are programmed by prenatal dexamethasone exposure and postnatal HF diet.

METHODS

Male offspring of Sprague-Dawley rats were divided into four experimental groups: normal diet, prenatal dexamethasone exposure, postnatal HF diet, and prenatal dexamethasone plus postnatal HF diet. Postnatal HF diet was prescribed from weaning to 6 months of age.

RESULTS

Prenatal dexamethasone and postnatal HF diet exerted synergistic effects on body weight and visceral adiposity, whereas prenatal dexamethasone and postnatal HF diet altered the metabolic profile and caused leptin dysregulation. Prenatal dexamethasone and postnatal HF diet distinctly influenced nutrient-sensing molecules and circadian-clock genes in adipose tissue. The mRNA expression of mTOR, AMPK-α2, PPAR-α, and PPAR-γ was suppressed by prenatal dexamethasone but enhanced by postnatal HF diet.

CONCLUSION

Prenatal dexamethasone and postnatal HF treatment cause dysregulation of nutrient-sensing molecules and circadian-clock genes in visceral adipose tissue. Characterizing altered nutrient-sensing molecules and circadian-clock genes has potential therapeutic relevance with respect to the pathogenesis and treatment of prenatal stress and postnatal HF diet-related metabolic disorders.

Prenatal dexamethasone and postnatal high-fat diet have a synergistic effect of elevating blood pressure through a distinct programming mechanism of systemic and adipose renin-angiotensin systems

Background

Hypertension may result from high-fat (HF) diet induced-obesity and overexposure to glucocorticoids in utero. Recent studies demonstrated the potent contribution of adipose tissue’s renin-angiotensin system (RAS) to systemic RAS, which plays a key role in regulating blood pressure (BP). In this study, we investigated the effects of prenatal dexamethasone (DEX) exposure and postnatal HF diet on RAS of adipose tissue.

Methods

RAS and BP of 6-month old rats exposed to prenatal DEX and/or postnatal HF diet were examined.

Results

Prenatal DEX plus postnatal HF exerted a synergistic effect on systolic BP. Prenatal DEX exposure suppressed plasma angiotensin (ANG) I and ANG II, whereas postnatal HF suppressed plasma ANG-(1–7) level. Prenatal DEX increased prorenin receptor and renin levels, but suppressed angiotensinogen (AGT) and angiotensin-converting-enzyme 1 (ACE1) mRNA expressions in adipose tissue. Postnatal HF increased AGT mRNA expression, but suppressed prorenin receptor, renin, ACE2, ANG II type 2 receptor (AT2R), and Mas receptor (MasR) mRNA expression levels.

Conclusions

Prenatal GC exposure altered the ACE1/ANG II/ANG II type 1 receptor (AT1R) axis, whereas postnatal HF negatively impacted the ACE2/ANG-(1–7)/MasR axis. Prenatal DEX exposure and postnatal HF synergistically elevated BP through a distinct programming mechanism of systemic and adipose RAS. Adipose RAS might be a target for precise hypertension treatment.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0701-0) contains supplementary material, which is available to authorized users.

Prenatal Dexamethasone and Postnatal High-Fat Diet Decrease Interferon Gamma Production through an Age-Dependent Histone Modification in Male Sprague-Dawley Rats

Overexposure to prenatal glucocorticoid (GC) disturbs hypothalamic-pituitary-adrenocortical axis-associated neuroendocrine metabolism and susceptibility to metabolic syndrome. A high-fat (HF) diet is a major environmental factor that can cause metabolic syndrome. We aimed to investigate whether prenatal GC plus a postnatal HF diet could alter immune programming in rat offspring. Pregnant Sprague-Dawley rats were given intraperitoneal injections of dexamethasone or saline at 14-21 days of gestation. Male offspring were then divided into four groups: vehicle, prenatal dexamethasone exposure, postnatal HF diet (VHF), and prenatal dexamethasone exposure plus a postnatal HF diet (DHF). The rats were sacrificed and adaptive immune function was evaluated. Compared to the vehicle, the DHF group had lower interferon gamma (IFN-γ) production by splenocytes at postnatal day 120. Decreases in H3K9 acetylation and H3K36me3 levels at the IFN-γ promoter correlated with decreased IFN-γ production. The impaired IFN-γ production and aberrant site-specific histone modification at the IFN-γ promoter by prenatal dexamethasone treatment plus a postnatal HF diet resulted in resilience at postnatal day 180. Prenatal dexamethasone and a postnatal HF diet decreased IFN-γ production through a site-specific and an age-dependent histone modification. These findings suggest a mechanism by which prenatal exposure to GC and a postnatal environment exert effects on fetal immunity programming.