Maternal high-fat diet increases vascular contractility in adult offspring in a sex-dependent manner

Maternal nutrition and effects on offspring vascular function

Maternal nutrition during pregnancy may have profound effects on the developing fetus and impact risk for cardiovascular disease later in life. Here, we provide a narrative review on the impact of maternal diet during pregnancy on offspring vascular function. We review studies reporting effects of maternal micronutrient (folic acid, iron) intakes, high-fat diets, dietary energy restriction, and low protein intake on offspring endothelial function. We discuss the differences in study design and outcomes and potential underlying mechanisms contributing to the vascular phenotypes observed in the offspring. We further highlight key gaps in the literature and identify targets for future investigations.

Maternal exercise upregulates the DNA methylation of Agtr1a to enhance vascular function in offspring of hypertensive rats

The angiotensin II signaling system regulates vascular dysfunction and is involved in the programming of hypertension. Maternal exercise has been linked to both short-term and long-term benefits for the mother and fetus. However, the impacts of maternal exercise on the intravascular renin-angiotensin system (RAS) in hypertensive offspring remain unexamined. This study examined whether maternal exercise has an epigenetic effect in repressing angiotensin II type 1 receptor (AT₁R) expression, which leads to favorable alterations in the mesenteric artery (MA) function of spontaneously hypertensive offspring. Spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) pregnant rats were randomly divided into an exercise group and a control group. Blood pressure, vascular tone, AT₁R protein and mRNA expression, and AT₁R gene (Agtr1a) promoter methylation status were examined in the MAs of 3-month-old male offspring. Maternal exercise significantly reduced the resting blood pressure and cardiovascular reactivity of offspring from SHRs. Furthermore, Ang II-AT₁R activity in regulating vascular tone and AT₁R expression was decreased in the MAs of the SHR offspring from the exercise groups. Importantly, exercise during gestation suppressed AT₁R expression via hypermethylation of the Agtr1a promoter region and upregulated DNA methyltransferase (DNMT) expression in MAs of SHR offspring. These results suggest that maternal exercise upregulates DNMT expression, resulting in hypermethylation and repression of the Agtr1a gene, which may prevent MA dysfunction in the offspring of SHRs. A mechanistic model on the epigenetics of exercise during pregnancy. Maternal exercise during pregnancy triggers hypermethylation and transcriptional suppression of the Agtr1a gene via increased DNMT1 and DNMT3B expression in MAs of SHR offspring. Downregulation of AT1R expression reduces the contribution of Ang II to vascular tone, ultimately improving vascular structure and function. VSMC vascular smooth muscle cell; Ang II angiotensin II; AT1aR angiotensin type 1 receptor (AT1R) alpha subtypes; Agtr1a AT1R alpha isoform gene; MAs mesenteric arteries; BP blood pressure.

Maternal high-fat diet consumption during pregnancy and lactation predisposes offspring to renal and metabolic injury later in life: comparative study of diets with different lipid contents

Accumulating evidence suggests that maternal overnutrition can result in a higher development risk of obesity and renal disease in the offspring's adulthood. The present study tested different lipid levels in the maternal diet during pregnancy and lactation and its repercussions on the offspring of Wistar rats. Offspring of 1, 7, 30 and 90-d-old were divided into the following groups: Control (CNT) - offspring of dams that consumed a standard chow diet (3.5% of lipids); Experimental 1 (EXP1) - offspring of dams exposed to a high-fat diet (HFD) (28% of lipids); and Experimental 2 (EXP2) - offspring of dams exposed to a HFD (40% of lipids). Regarding maternal data, there was a decrease in the amount of diet ingested by EXP2. Daily caloric intake was higher in EXP1, while protein and carbohydrate intakes were lower in EXP2. While lipid intake was higher in the experimental groups, EXP1 consumed more lipids than EXP2, despite the body weight gain being higher in EXP2. Adult offspring from EXP1 presented higher blood glucose. Regarding morphometric analysis, in both experimental groups, there was an increase in the glomerular tuft and renal corpuscle areas, but an increase in the capsular space area only in EXP1. There was a decrease in the glomerular filtration rate (GFR) in EXP1, in contrast to an increase in GFR of EXP2, along with an increase in urinary protein excretion. In conclusion, the maternal HFDs caused significant kidney damage in offspring, but had different repercussions on the type and magnitude of recorded change.

Increased Arterial Responsiveness to Angiotensin II in Mice Conceived by Assisted Reproductive Technologies

Since the first report in 1978, the number of individuals conceived by Assisted Reproductive Technologies (ART) has grown incessantly. In parallel, with the recent emergence of possible underlying mechanisms of ART-induced epigenetic changes in the renin-angiotensin system, the cardiovascular repercussions of ART in mice and human offspring (including arterial hypertension, vascular dysfunction, and cardiac remodeling) have become increasingly recognized. Here, we hypothesized that ART may increase arterial responsiveness to angiotensin II (ANG II) by epigenetically modifying the expression of its receptors. To test this hypothesis, we assessed the vasoconstrictor responsiveness to ANG II in isolated aortas from ART and control mice. We also examined ANG II receptor (ATR) type 1 and 2 expression and the promoter methylation of the At1aR, At1bR and At2R genes. We found that the vasoconstrictor response to ANG II was markedly increased in ART mice compared to controls. This exaggerated vasoconstrictor responsiveness in ART mice correlated with a significant increase in the ANG II receptor (ATR) type 1 to ATR type 2 protein expression ratio in the aorta; this was mainly driven by an increase in AT1R expression, and by hypomethylation of two CpG sites located in the At1bR gene promoter leading to increased transcription of the gene. We conclude that in mice, ART increase the vasoconstrictor response to ANG II in the aorta by epigenetically causing an imbalance between the expression of vasoconstrictor (AT1R) and vasodilator (AT2R) ANG II receptors. Unbalanced expression of AT1R and AT2R receptors seems to be a novel mechanism contributing to ART-induced arterial hypertension in mice.

Association between High-Fat Diet during Pregnancy and Heart Weight of the Offspring: A Multivariate and Mediation Analysis

Maternal nutrition and health status in the peri-pregnancy period are closely related to offspring health. Currently, population studies are unable to provide quantitative relationships and effective measures of peri-pregnancy high-fat diet and offspring myocardial remodeling due to the difficulty of obtaining human samples. This study aimed to establish the mouse models of maternal obesity and high-fat diet supplementation and deprivation during pregnancy. The effects of obesity, periconceptional high-fat diet window, fetal weight, sex, and placental weight on myocardial remodeling in the offspring were measured by single-factor and multiple-factor regression analyses. Moreover, the relationship between perinatal high-fat diet/fetal weight and offspring myocardial remodeling was explored using the mediation analysis model. The multivariate analysis showed that the heart weight to body weight (HW/BW) ratio of the offspring decreased by -1.6525 mg/g for every 1-g increase in fetal weight. The offspring HW/BW increased by 1.1967 mg/g if pregnant women were exposed to a high-fat diet throughout pregnancy. The mediation analysis model of a perinatal high-fat diet for the myocardial remodeling of offspring revealed that fetal weight had a suppression effect on the myocardial weight of offspring, accounting for 60.70%; also, it had a mediating effect on the HW/BW of offspring, accounting for 17.10%. Moreover, subgroup analysis showed an interaction between offspring sex and HW/BW in a maternal high-fat diet during pregnancy. Additionally, a quantitative real-time polymerase chain reaction experiment further proved that a perinatal high-fat diet could change the important indicators of myocardial remodeling in offspring. In conclusion, this study found that a high-fat diet in the periconceptional period influenced factors in offspring myocardial remodeling. Moreover, maternal high-fat diet deprivation attenuated the changes in offspring myocardial remodeling. In addition, the role of fetal weight in mediating maternal high-fat diet-mediated offspring myocardial remodeling was quantified. Our study showed that a sensible and healthy diet during the perinatal period, especially during pregnancy, played a positive role in the health of the offspring.

Estrogen normalizes maternal HFD-induced vascular dysfunction in offspring by regulating ATR

Previous studies have shown that female offspring are resistant to fetal high-fat diet (HFD)-induced programming of heightened vascular contraction; however, the underlying mechanisms remain unclear. The present study tested the hypothesis that estrogen plays a key role in protecting females from fetal programming of increased vascular contraction induced by maternal HFD exposure. Pregnant rats were fed a normal diet (ND) or HFD (60% kcal from fat). Ovariectomy (OVX) and 17β-estradiol (E₂) replacement were performed on 8-week-old female offspring. Aortas were isolated from adult female offspring. Maternal HFD exposure increased angiotensin II (Ang II)-induced contractions of the aorta in adult OVX offspring, which was abrogated by E₂ replacement. The AT₁ receptor (AT₁R) antagonist losartan (10 μM), but not the AT₂ receptor (AT₂R) antagonist PD123319 (10 μM), completely blocked Ang II-induced contractions in both ND and HFD offspring. In addition, HFD exposure caused a decrease in endothelium-dependent relaxations induced by acetylcholine (ACh) in adult OVX but not OVX-E₂ offspring. However, it had no effect on sodium nitroprusside (SNP)-induced endothelium-independent aorta relaxation in any of the six groups. Maternal HFD feeding increased AT₁R, but not AT₂R, leading to an increased AT₁R/AT₂R ratio in HFD-exposed OVX offspring, associated with selective decreases in DNA methylation at the AT_1aR promoter, which was ameliorated by E₂ replacement. Our results indicated that estrogen play a key role in sex differences of maternal HFD-induced vascular dysfunction and development of hypertensive phenotype in adulthood by differently regulating vascular AT₁R and AT₂R gene expression through a DNA methylation mechanism.