Programming of maternal and offspring disease: impact of growth restriction, fetal sex and transmission across generations

Maternal exercise programs placental miR-495-5p-mediated Snx7 expression and kynurenic acid metabolic pathway induced by prenatal high-fat diet: Based on miRNA-seq, transcriptomics, and metabolomics

Poor intrauterine environments increase the prevalence of chronic metabolic diseases in offspring, whereas maternal exercise is an effective measure to break this vicious intergenerational cycle. Placenta is increasingly being studied to explore its role in maternal-fetal metabolic cross-talk. The association between placental miRNA and offspring development trajectories has been established, yet the specific role and mechanism thereof in maternal exercise-induced metabolic protection remain elusive. Here, C57BL/6 female mice were subjected to either a normal control or a high-fat diet (HFD), half of the HFD-fed dams were housed with voluntary wheel running for 3 weeks before and during gestation. At embryonic day 18.5, we sacrificed parturient mice and then conducted miRNA-seq, transcriptomic, and metabolomic profiling of the placenta. Our data revealed that maternal HFD resulted in significant alterations in both miRNA and gene expressions, as well as metabolic pathways of the placenta, whereas prenatal exercise negated these perturbations. The common differentially expressed transcripts among three groups were enriched in multiple critical pathways involving energy expenditure, signal transduction, and fetal development. Through integrated analysis of multiomics data, we speculated that maternal exercise reversed the suppression of miR-495-5p induced by HFD, thereby inhibiting miR-495-5p-targeted Snx7 and modulating kynurenic acid production. These datasets provided novel mechanistic insight into how maternal exercise positively affects the metabolic homeostasis of offspring. The discovered important miRNAs, mRNAs, and metabolites could be promising predictive and therapeutic targets for protecting offspring metabolic health.

Analysis of the evolution of placental oxidative stress research from a bibliometric perspective

Background

Research on placental oxidative stress is pivotal for comprehending pregnancy-related physiological changes and disease mechanisms. Despite recent advancements, a comprehensive review of current status, hotspots, and trends remains challenging. This bibliometric study systematically analyzes the evolution of placental oxidative stress research, offering a reference for future studies.

Objective

To conduct a comprehensive bibliometric analysis of the literature on placental oxidative stress to identify research hotspots, trends, and key contributors, thereby providing guidance for future research.

Methods

Relevant data were retrieved from the Web of Science Core Collection database and analyzed using VOSviewer, CiteSpace, and the bibliometrix package. An in-depth analysis of 4,796 publications was conducted, focusing on publication year, country/region, institution, author, journal, references, and keywords. Data collection concluded on 29 April 2024.

Results

A total of 4,796 papers were retrieved from 1,173 journals, authored by 18,835 researchers from 4,257 institutions across 103 countries/regions. From 1991 to 2023, annual publications on placental oxidative stress increased from 7 to 359. The United States (1,222 publications, 64,158 citations), the University of Cambridge (125 publications, 13,562 citations), and Graham J. Burton (73 publications, 11,182 citations) were the most productive country, institution, and author, respectively. The journal Placenta had the highest number of publications (329) and citations (17,152), followed by the International Journal of Molecular Sciences (122 publications). The most frequent keywords were "oxidative stress," "expression," "pregnancy," "preeclampsia," and "lipid peroxidation." Emerging high-frequency keywords included "gestational diabetes mellitus," "health," "autophagy," "pathophysiology," "infection," "preterm birth," "stem cell," and "inflammation."

Conclusion

Over the past 3 decades, research has concentrated on oxidative stress processes, antioxidant mechanisms, pregnancy-related diseases, and gene expression regulation. Current research frontiers involve exploring pathophysiology and mechanisms, assessing emerging risk factors and environmental impacts, advancing cell biology and stem cell research, and understanding the complex interactions of inflammation and immune regulation. These studies elucidate the mechanisms of placental oxidative stress, offering essential scientific evidence for future intervention strategies, therapeutic approaches, and public health policies.

DNA methylation landscape in pregnancy-induced hypertension: progress and challenges

Gestational hypertension (PIH), especially pre-eclampsia (PE), is a common complication of pregnancy. This condition poses significant risks to the health of both the mother and the fetus. Emerging evidence suggests that epigenetic modifications, particularly DNA methylation, may play a role in initiating the earliest pathophysiology of PIH. This article describes the relationship between DNA methylation and placental trophoblast function, genes associated with the placental microenvironment, the placental vascular system, and maternal blood and vascular function, abnormalities of umbilical cord blood and vascular function in the onset and progression of PIH, as well as changes in DNA methylation in the progeny of PIH, in terms of maternal, fetal, and offspring. We also explore the latest research on DNA methylation-based early detection, diagnosis and potential therapeutic strategies for PIH. This will enable the field of DNA methylation research to continue to enhance our understanding of the epigenetic regulation of PIH genes and identify potential therapeutic targets.

A Review of Fetal Development in Pregnancies with Maternal Type 2 Diabetes Mellitus (T2DM)-Associated Hypothalamic-Pituitary-Adrenal (HPA) Axis Dysregulation: Possible Links to Pregestational Prediabetes

Research has identified fetal risk factors for adult diseases, forming the basis for the Developmental Origins of Health and Disease (DOHaD) hypothesis. DOHaD suggests that maternal insults during pregnancy cause structural and functional changes in fetal organs, increasing the risk of chronic diseases like type 2 diabetes mellitus (T2DM) in adulthood. It is proposed that altered maternal physiology, such as increased glucocorticoid (GC) levels associated with a dysregulated hypothalamic-pituitary-adrenal (HPA) axis in maternal stress and T2DM during pregnancy, exposes the fetus to excess GC. Prenatal glucocorticoid exposure reduces fetal growth and programs the fetal HPA axis, permanently altering its activity into adulthood. This programmed HPA axis is linked to increased risks of hypertension, cardiovascular diseases, and mental disorders in adulthood. With the global rise in T2DM, particularly among young adults of reproductive age, it is crucial to prevent its onset. T2DM is often preceded by a prediabetic state, a condition that does not show any symptoms, causing many to unknowingly progress to T2DM. Studying prediabetes is essential, as it is a reversible stage that may help prevent T2DM-related pregnancy complications. The existing literature focuses on HPA axis dysregulation in T2DM pregnancies and its link to fetal programming. However, the effects of prediabetes on HPA axis function, specifically glucocorticoid in pregnancy and fetal outcomes, are not well understood. This review consolidates research on T2DM during pregnancy, its impact on fetal programming via the HPA axis, and possible links with pregestational prediabetes.

The Molecular Basis of the Augmented Cardiovascular Risk in Offspring of Mothers with Hypertensive Disorders of Pregnancy

The review examines the impact of maternal preeclampsia (PE) on the cardiometabolic and cardiovascular health of offspring. PE, a hypertensive disorder of pregnancy, is responsible for 2 to 8% of pregnancy-related complications. It significantly contributes to adverse outcomes for their infants, affecting the time of birth, the birth weight, and cardiometabolic risk factors such as blood pressure, body mass index (BMI), abdominal obesity, lipid profiles, glucose, and insulin. Exposure to PE in utero predisposes offspring to an increased risk of cardiometabolic diseases (CMD) and cardiovascular diseases (CVD) through mechanisms that are not fully understood. The incidence of CMD and CVD is constantly increasing, whereas CVD is the main cause of morbidity and mortality globally. A complex interplay of genes, environment, and developmental programming is a plausible explanation for the development of endothelial dysfunction, which leads to atherosclerosis and CVD. The underlying molecular mechanisms are angiogenic imbalance, inflammation, alterations in the renin-angiotensin-aldosterone system (RAAS), endothelium-derived components, serotonin dysregulation, oxidative stress, and activation of both the hypothalamic-pituitary-adrenal axis and hypothalamic-pituitary-gonadal axis. Moreover, the potential role of epigenetic factors, such as DNA methylation and microRNAs as mediators of these effects is emphasized, suggesting avenues for future research and therapeutic interventions.

Exercise enhances placental labyrinth trophoblast development by activation of PGC-1α and FNDC5/irisin†

Placental chorion/labyrinth trophoblasts are energy demanding which is met by the mitochondrial oxidative phosphorylation. Exercise enhances placental development and mitochondrial biogenesis, but the underlying mechanisms remain poorly understood. To address, female C57BL/6 J mice were randomly assigned into two groups: a control group and an exercise (EX) group. All animals were acclimated to treadmill exercise for 1 week before mating, but only the EX group was subjected to daily exercise during pregnancy from embryonic day (E) 1.5 to E16.5. Placenta were collected at E18.5 for biochemical and histochemical analyses, and primary trophoblast cells were isolated from the E18.5 placenta for further analyses. The data showed that exercise during pregnancy promoted the expression of syncytiotrophoblast cell markers, indicating trophoblast cell differentiation, which was closely associated with elevated mitochondrial biogenesis and oxidative metabolism in the E18.5 placenta. In addition, exercise during pregnancy activated peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α), which was associated with upregulated placental α-ketoglutarate and the expression of isocitrate dehydrogenases and ten-eleven translocations, facilitating DNA demethylation of the Pgc1a promoter. Furthermore, exercise upregulated fibronectin type III domain containing 5 expression and the secretion of its cleaved form, irisin, which is known to activate PGC-1α. These data suggest that exercise-induced activation of PGC-1α, via epigenetic modifications, is responsible for promoting mitochondrial energy metabolism and chorion/labyrinth trophoblast development.

Asymmetric growth-limiting development of the female conceptus

Introduction

Sex differences in prenatal growth may contribute to sex-dependent programming effects on postnatal phenotype.

Methods

We integrated for the first time phenotypic, histomorphological, clinico-chemical, endocrine and gene expression analyses in a single species, the bovine conceptus at mid-gestation.

Results

We demonstrate that by mid-gestation, before the onset of accelerated growth, the female conceptus displays asymmetric lower growth compared to males. Female fetuses were smaller with lower ponderal index and organ weights than males. However, their brain:body weight, brain:liver weight and heart:body weight ratios were higher than in males, indicating brain and heart 'sparing'. The female placenta weighed less and had lower volumes of trophoblast and fetal connective tissue than the male placenta. Female umbilical cord vessel diameters were smaller, and female-specific relationships of body weight and brain:liver weight ratios with cord vessel diameters indicated that the umbilico-placental vascular system creates a growth-limiting environment where blood flow is redistributed to protect brain and heart growth. Clinico-chemical indicators of liver perfusion support this female-specific growth-limiting phenotype, while lower insulin-like growth factor 2 (IGF2) gene expression in brain and heart, and lower circulating IGF2, implicate female-specific modulation of key endocrine mediators by nutrient supply.

Conclusion

This mode of female development may increase resilience to environmental perturbations in utero and contribute to sex-bias in programming outcomes including susceptibility to non-communicable diseases.

Gestational Caloric Restriction Alters Adipose Tissue Methylome and Offspring's Metabolic Profile in a Swine Model

Limited nutrient supply to the fetus results in physiologic and metabolic adaptations that have unfavorable consequences in the offspring. In a swine animal model, we aimed to study the effects of gestational caloric restriction and early postnatal metformin administration on offspring's adipose tissue epigenetics and their association with morphometric and metabolic variables. Sows were either underfed (30% restriction of total food) or kept under standard diet during gestation, and piglets were randomly assigned at birth to receive metformin (n = 16 per group) or vehicle treatment (n = 16 per group) throughout lactation. DNA methylation and gene expression were assessed in the retroperitoneal adipose tissue of piglets at weaning. Results showed that gestational caloric restriction had a negative effect on the metabolic profile of the piglets, increased the expression of inflammatory markers in the adipose tissue, and changed the methylation of several genes related to metabolism. Metformin treatment resulted in positive changes in the adipocyte morphology and regulated the methylation of several genes related to atherosclerosis, insulin, and fatty acids signaling pathways. The methylation and gene expression of the differentially methylated FASN, SLC5A10, COL5A1, and PRKCZ genes in adipose tissue associated with the metabolic profile in the piglets born to underfed sows. In conclusion, our swine model showed that caloric restriction during pregnancy was associated with impaired inflammatory and DNA methylation markers in the offspring's adipose tissue that could predispose the offspring to later metabolic abnormalities. Early metformin administration could modulate the size of adipocytes and the DNA methylation changes.

Cardiovascular effect of preeclampsia upon offspring development: Are (Pro) renin-renin receptor ((P)RR) and gender related?

Objectives

Preeclampsia (PE) is a complication of pregnancy that might increase progeny risk of cardiovascular and metabolic problems, mainly in males. Renin angiotensin aldosterone system is known to be involved. (Pro) renin/renin receptor ((P)RR) has been shown to participate in cardiovascular pathology. The aim of this work was to evaluate (P)RR expression and function upon cardiovascular and renal tissues from PE dams' offspring.

Materials and Methods

We used offspring from normal pregnant and preeclamptic rats, evaluating body, heart, aorta and kidney weight, length, and blood pressure along 3 months after birth. Subsets of animals received handle region peptide (HRP) (0.2 mg/Kg, sc). Another group received vehicle. Animals were sacrificed at first, second, and third months of age, tissues were extracted and processed for immunoblot to detect (P)RR, PLZF, β-catenin, DVL-1, and PKCα. (P)RR and PLZF were also measured by RT-PCR.

Results

We found that offspring developed hypertension. Male descendants remained hypertensive throughout the whole experiment. Female animals tended to recover at second month and returned to normal blood pressure at third month. HRP treatment diminished hypertension in both male and female animals. Morphological evaluations showed changes in heart, aorta, and kidney weight, and HRP reverted this effect. Finally, we found that (P)RR, PLZF, and canonical WNT transduction pathway molecules were stimulated by PE, and HRP treatment abolished this increase.

Conclusion

These findings suggest that PE can induce hypertension in offspring, and (P)RR seems to play an important role through the canonical WNT pathway and that gender seems to influence this response.

The role of gonadal hormones and sex chromosomes in sex-dependent effects of early nutrition on metabolic health

Early-life conditions such as prenatal nutrition can have long-term effects on metabolic health, and these effects may differ between males and females. Understanding the biological mechanisms underlying sex differences in the response to early-life environment will improve interventions, but few such mechanisms have been identified, and there is no overall framework for understanding sex differences. Biological sex differences may be due to chromosomal sex, gonadal sex, or interactions between the two. This review describes approaches to distinguish between the roles of chromosomal and gonadal sex, and summarizes findings regarding sex differences in metabolism. The Four Core Genotypes (FCG) mouse model allows dissociation of the sex chromosome genotype from gonadal type, whereas the XY* mouse model can be used to distinguish effects of X chromosome dosage vs the presence of the Y chromosome. Gonadectomy can be used to distinguish between organizational (permanent) and activational (reversible) effects of sex hormones. Baseline sex differences in a variety of metabolic traits are influenced by both activational and organizational effects of gonadal hormones, as well as sex chromosome complement. Thus far, these approaches have not been widely applied to examine sex-dependent effects of prenatal conditions, although a number of studies have found activational effects of estradiol to be protective against the development of hypertension following early-life adversity. Genes that escape X chromosome inactivation (XCI), such as Kdm5c, contribute to baseline sex-differences in metabolism, while Ogt, another XCI escapee, leads to sex-dependent responses to prenatal maternal stress. Genome-wide approaches to the study of sex differences include mapping genetic loci influencing metabolic traits in a sex-dependent manner. Seeking enrichment for binding sites of hormone receptors among genes showing sexually-dimorphic expression can elucidate the relative roles of hormones. Using the approaches described herein to identify mechanisms underlying sex-dependent effects of early nutrition on metabolic health may enable the identification of fundamental mechanisms and potential interventions.

Placental assessment using spectral analysis of the envelope of umbilical venous waveforms in sheep

INTRODUCTION

This study was designed to test the efficacy of an ultrasound flow measurement method to evaluate placental function in a hyperandrogenic sheep model that produces placental morphologic changes and an intrauterine growth restriction (IUGR) phenotype.

MATERIALS AND METHODS

Pregnant ewes were assigned randomly between control (n = 12) and testosterone-treatment (T-treated, n = 22) groups. The T-treated group was injected twice weekly intramuscularly (IM) with 100 mg testosterone propionate. Control sheep were injected with corn oil vehicle. Lambs were delivered at 119.5 ± 0.48 days gestation. At the time of delivery of each lamb, flow spectra were generated from one fetal artery and two fetal veins, and the spectral envelopes examined using fast Fourier transform analysis. Base 10 logarithms of the ratio of the amplitudes of the maternal and fetal spectral peaks (LRSP) in the venous power spectrum were compared in the T-treated and control populations. In addition, we calculated the resistive index (RI) for the artery defined as ((peak systole - min diastole)/peak systole). Two-tailed T-tests were used for comparisons.

RESULTS

LRSPs, after removal of significant outliers, were -0.158 ± 0.238 for T-treated and 0.057 ± 0.213 for control (p = 0.015) animals. RIs for the T-treated sheep fetuses were 0.506 ± 0.137 and 0.497 ± 0.086 for controls (p = 0.792) DISCUSSION: LRSP analysis distinguishes between T-treated and control sheep, whereas RIs do not. LRSP has the potential to identify compromised pregnancies.

Feto-maternal cholesterol transport regulated by β-Klotho-FGF15 axis is essential for fetal growth

β-Klotho (β-KL) is indispensable to regulate lipid, glucose, and energy metabolism in adult animals. β-KL is highly expressed in the yolk sac, but its role in the developmental stages has not been established. We hypothesized that β-KL is required for metabolic regulation in the embryo and aimed to clarify the role of β-KL during development. Here, we show that β-KL regulates feto-maternal cholesterol transport through the yolk sac by mediating FGF 15 signaling, and also that impairment of the β-KL-FGF15 axis causes fetal growth restriction (FGR). Embryos of β- kl knockout (β-kl-/-) mice were morphologically normal but exhibited FGR before placental maturation. The body weight of β-kl-/- mice remained lower after birth. β-KL deletion reduced cholesterol supply from the maternal blood and led to lipid shortage in the embryos. These phenotypes were similar to those of embryos lacking FGF15, indicating that β-KL-FGF15 axis is essential for growth and lipid regulation in the embryonic stages. Our findings suggest that lipid abnormalities in early gestation provoke FGR, leading to reduced body size in later life.

Nutrition and Developmental Origins of Kidney Disease

The developmental programming hypothesis proposes that adverse environmental insults during critical developmental periods increase the risk of diseases later in life. The kidneys are deemed susceptible to such a process, although the exact mechanisms remain elusive. Many factors have been reported to contribute to the developmental origin of chronic kidney diseases (CKD), among which peri-gestational nutrition has a central role, affecting kidney development and metabolism. Physiologically, the link between malnutrition, reduced glomerular numbers, and increased blood pressure is key in the developmental programming of CKD. However, recent studies regarding oxidative stress, mitochondrial dysfunction, epigenetic modifications, and metabolic changes have revealed potential novel pathways for therapeutic intervention. This review will discuss the role of imbalanced nutrition in the development of CKD.

Maternal hypothyroidism in rats impairs placental nutrient transporter expression, increases labyrinth zone size, and impairs fetal growth

INTRODUCTION

Hypothyroidism during pregnancy is associated with fetal growth restriction (FGR). FGR is commonly caused by placental insufficiency and yet the role of hypothyroidism in placental regulation of fetal growth is unknown. This study aimed to investigate the effects of maternal hypothyroidism on placental nutrient transporter expression, placental morphology, and placental metabolism.

METHODS

Hypothyroidism was induced in female Sprague-Dawley rats by adding methimazole (MMI) to drinking water at moderate (MOD, MMI at 0.005% w/v) and severe (SEV, MMI at 0.02% w/v) doses from one week prior to pregnancy and throughout gestation. Maternal and fetal tissues were collected on embryonic day 20 (E20).

RESULTS

Hypothyroidism reduced fetal weight (PTrt<0.001) despite causing fetal hyperglycaemia (PTrt = 0.016). Placental weight was not affected by hypothyroidism however placental efficiency was reduced (PTrt<0.001), as was the junctional zone (JZ):labyrinth zone (LZ) weight ratio (PTrt = 0.005). LZ glycogen content was increased (PTrt = 0.029) and while mRNA expression of glucose transporters was reduced by hypothyroidism, only GLUT1 protein expression was reduced in male LZs. Maternal hypothyroidism reduced mitochondrial content (PTrt = 0.031), particularly in SEV males relative to CON males (P = 0.004). Protein expression of Complex V (P < 0.001) and Complex III (P = 0.002) of the electron transport chain were also reduced in males. Maternal hypothyroidism reduced LZ (PTrt<0.001) and fetal plasma triglycerides (P = 0.019) while fetal free fatty acids and the expression of LZ lipid transporters was not affected.

DISCUSSION

Overall, maternal hypothyroidism may lead to FGR through reduced maternal T4 availability, changes to placental morphology, altered nutrient transporter expression and sex-specific effects on placental metabolism. Changes to LZ glycogen and triglyceride stores as well as mitochondrial content suggest a metabolic shift from oxidative phosphorylation to anaerobic glycolysis in males. These changes also likely impact fetal substrate availability and therefore fetal growth.

Environmental exposure to outdoor artificial light at night during pregnancy and fetal size: A prospective cohort study

BACKGROUND

Previous studies suggested outdoor artificial light at night (ALAN) exposure may contribute to children and adult obesity, but less is known about the associations of outdoor ALAN exposure during pregnancy with fetal size.

METHODS

From 2015 to 2021, 6210 mother-child pairs were included. Average outdoor ALAN levels during pregnancy were measured using satellite imaging data. Fetal biparietal diameter, head circumference, abdominal circumference (AC), and femur length were measured before delivery with ultrasonography. We also collected anthropometric birth outcomes, including birth length, birth weight, macrosomia, low birth weight, small for gestational age, and large for gestational age at delivery. Multivariable linear regression models and binary logistic regression models were used to examine the potential associations of outdoor ALAN with fetal size adjusting for a broad set of potential confounds.

RESULTS

An IQR (14.87 nW/cm²/sr) increase in outdoor ALAN during pregnancy was associated with 1.30 (β = 1.30, 95 % CI: 0.31,2.29) higher AC percentiles and 13 % (OR = 1.13, 95 % CI: 1.00,1.27) higher odds of macrosomia after adjusting confounders. In sex stratification analysis, an IQR (14.87 nW/cm²/sr) increase in outdoor ALAN during pregnancy was associated with 1.65 (β = 1.65, 95 % CI: 0.24,3.06) higher fetal AC percentiles and 27 % (OR = 1.27, 95 % CI: 1.06,1.53) higher odds of macrosomia in females.

CONCLUSIONS

Our findings suggest that higher outdoor ALAN exposure during pregnancy is associated with larger fetal AC and a higher risk of macrosomia, particularly in the female fetus. Future studies are needed to verify these preliminary findings and identify potential mechanisms for the association.

Severe Diabetes Induction as a Generational Model for Growth Restriction of Rat

We used uncontrolled maternal diabetes as a model to provoke fetal growth restriction in the female in the first generation (F₁) and to evaluate reproductive outcomes and the possible changes in metabolic systems during pregnancy, as well as the repercussions at birth in the second generation (F₂). For this, nondiabetic and streptozotocin-induced severely diabetic Sprague-Dawley rats were mated to obtain female pups (F₁), which were classified as adequate (AGA) or small (SGA) for gestational weight. Afterward, we composed two groups: F₁ AGA from nondiabetic dams (Control) and F₁ SGA from severely diabetic dams (Restricted) (n minimum = 10 animals/groups). At adulthood, these rats were submitted to the oral glucose tolerance test, mated, and at day 17 of pregnancy, blood samples were collected to determine glucose and insulin levels for assessment of insulin resistance. At the end of the pregnancy, the blood and liver samples were collected to evaluate redox status markers, and reproductive, fetal, and placental outcomes were analyzed. Maternal diabetes was responsible for increased SGA rates and a lower percentage of AGA fetuses (F₁ generation). The restricted female pups from severely diabetic dams presented rapid neonatal catch-up growth, glucose intolerance, and insulin resistance status before and during pregnancy. At term pregnancy of F₁ generation, oxidative stress status was observed in the maternal liver and blood samples. In addition, their offspring (F₂ generation) had lower fetal weight and placental efficiency, regardless of gender, which caused fetal growth restriction and confirmed the fetal programming influence.

miR-18a-5p Is Involved in the Developmental Origin of Prostate Cancer in Maternally Malnourished Offspring Rats: A DOHaD Approach

The Developmental Origins of Health and Disease (DOHaD) concept correlates early life exposure to stressor conditions with the increased incidence of non-communicable chronic diseases, including prostate cancer (PCa), throughout the life span. However, the molecular mechanisms involved in this process remain poorly understood. In this study, the deregulation of two miRNAs (rno-miR-18a-5p and rno-miR-345-3p) was described in the ventral prostate VP of old rats born to dams fed with a low protein diet (LPD) (6% protein in the diet) during gestational and lactational periods. Integrative analysis of the (VP) transcriptomic and proteomic data revealed changes in the expression profile of 14 identified predicted targets of these two DE miRNAs, which enriched terms related to post-translational protein modification, metabolism of proteins, protein processing in endoplasmic reticulum, phosphonate and phosphinate metabolism, the calnexin/calreticulin cycle, metabolic pathways, N-glycan trimming in the ER and the calnexin/calreticulin cycle, hedgehog ligand biogenesis, the ER-phagosome pathway, detoxification of reactive oxygen species, antigenprocessing-cross presentation, RAB geranylgeranylation, collagen formation, glutathione metabolism, the metabolism of xenobiotics by cytochrome P450, and platinum drug resistance. RT-qPCR validated the deregulation of the miR-18a-5p/P4HB (prolyl 4-hydroxylase subunit beta) network in the VP of older offspring as well as in the PNT-2 cells transfected with mimic miR-18a-5p. Functional in vitro studies revealed a potential modulation of estrogen receptor α (ESR1) by miR-18a-5p in PNT-2 cells, which was also confirmed in the VP of older offspring. An imbalance of the testosterone/estrogen ratio was also observed in the offspring rats born to dams fed with an LPD. In conclusion, deregulation of the miR-18a-5p/P4HB network can contribute to the developmental origins of prostate cancer in maternally malnourished offspring, highlighting the need for improving maternal healthcare during critical windows of vulnerability early in life.

The Long-Term Effects of Prenatal Hypoxia on Coronary Artery Function of the Male and Female Offspring

Prenatal hypoxia predisposes the offspring to the development of cardiovascular (CV) dysfunction in adult life. Using a rat model, we assessed the effect of prenatal hypoxia on vasoconstrictive and vasodilative mechanisms in left anterior descending coronary arteries of 4- and 9.5-month-old offspring. Endothelium-dependent relaxation to methylcholine and vasoconstriction responses to endothelin-1 (ET-1) were assessed by wire myography. Prenatal hypoxia impaired endothelium-dependent vasodilation in 4- and 9.5-month-old offspring. Inhibition of nitric oxide (NO) synthase prevented coronary artery relaxation in all groups. Inhibition of prostaglandin H synthase (PGHS) improved relaxation in prenatally hypoxic males and tended to improve vasorelaxation in females, suggesting that impaired vasodilation was mediated via increased PGHS-dependent vasoconstriction. An enhanced contribution of endothelium-dependent hyperpolarization to coronary artery vasodilation was observed in prenatally hypoxic males and females. No changes in endothelial NO synthase (eNOS) and PGHS-1 expressions were observed, while PGHS-2 expression was decreased in only prenatally hypoxic males. At 4 months, ET-1 responses were similar between groups, while ET_B inhibition (with BQ788) tended to decrease ET-1-mediated responses in only prenatally hypoxic females. At 9.5 months, ET-1-mediated responses were decreased in only prenatally hypoxic females. Our data suggest that prenatal hypoxia has long-term similar effects on the mechanisms of impaired endothelium-dependent vasodilation in coronary arteries from adult male and female offspring; however, coronary artery contractile capacity is impaired only in prenatally hypoxic females. Understanding the mechanistic pathways involved in the programming of CV disease may allow for the development of therapeutic interventions.

Fetal Exposure to Maternal Smoking and Neonatal Metabolite Profiles

Fetal tobacco exposure has persistent effects on growth and metabolism. The underlying mechanisms of these relationships are yet unknown. We investigated the associations of fetal exposure to maternal smoking with neonatal metabolite profiles. In a population-based cohort study among 828 mother-infant pairs, we assessed maternal tobacco use by questionnaire. Metabolite concentrations of amino acids, non-esterified fatty acids, phospholipids and carnitines were determined by using LC-MS/MS in cord blood samples. Metabolite ratios reflecting metabolic pathways were computed. Compared to non-exposed neonates, those exposed to first trimester only tobacco smoking had lower neonatal mono-unsaturated acyl-alkyl-phosphatidylcholines (PC.ae) and alkyl-lysophosphatidylcholines (Lyso.PC.e) 18:0 concentrations. Neonates exposed to continued tobacco smoking during pregnancy had lower neonatal mono-unsaturated acyl-lysophosphatidylcholines (Lyso.PC.a), Lyso.PC.e.16:0 and Lyso.PC.e.18:1 concentration (False discovery rate (FDR) p-values < 0.05). Dose-response associations showed the strongest effect estimates in neonates whose mothers continued smoking ≥5 cigarettes per day (FDR p-values < 0.05). Furthermore, smoking during the first trimester only was associated with altered neonatal metabolite ratios involved in the Krebs cycle and oxidative stress, whereas continued smoking during pregnancy was associated with inflammatory, transsulfuration, and insulin resistance markers (p-value < 0.05). Thus, fetal tobacco exposure seems associated with neonatal metabolite profile adaptations. Whether these changes relate to later life metabolic health should be studied further.

Maternal NO2 exposure disturbs the long noncoding RNA expression profile in the lungs of offspring in time-series patterns

Gestation is a sensitive window to nitrogen dioxide (NO₂) exposure, which may disturb fetal lung development and lung function later in life. Animal and epidemiological studies indicated that long noncoding RNAs (lncRNAs) participate in abnormal lung development induced by environmental pollutant exposure. In the present study, pregnant C57BL/6J mice were exposed to 2.5 ppm NO₂ (mimicking indoor occupational exposure) or clean air, and lncRNAs expression profiles in the lungs of offspring mice were determined by lncRNA-seq on embryonic day 13.5 (E13.5), E18.5, postnatal day 1 (P1), and P14. The lung histopathology examination of offspring was performed, followed by weighted gene coexpression network analysis (WGCNA), prediction of lncRNAs-target genes, and the biological processes enrichment analysis of lncRNAs. Our results indicated that maternal NO₂ exposure induced hypoalveolarization on P14 and differentially expressed lncRNAs showed a time-series pattern. Following WGCNA and enrichment analysis, 2 modules participated in development-related pathways. Importantly, the expressions of related genes were altered, some of which were confirmed to be related to abnormal vascular development and even lung diseases. The research points out that the maternal NO₂ exposure leads to abnormal lung development in offspring that might be related to altered lncRNAs expression profiles with time-series-pattern.

Hypertension and renal disease programming: focus on the early postnatal period

The developmental origin of hypertension and renal disease is a concept highly supported by strong evidence coming from both human and animal studies. During development there are periods in which the organs are more vulnerable to stressors. Such periods of susceptibility are also called 'sensitive windows of exposure'. It was shown that as earlier an adverse event occurs; the greater are the consequences for health impairment. However, evidence show that the postnatal period is also quite important for hypertension and renal disease programming, especially in rodents because they complete nephrogenesis postnatally, and it is also important during preterm human birth. Considering that the developing kidney is vulnerable to early-life stressors, renal programming is a key element in the developmental programming of hypertension and renal disease. The purpose of this review is to highlight the great number of studies, most of them performed in animal models, showing the broad range of stressors involved in hypertension and renal disease programming, with a particular focus on the stressors that occur during the early postnatal period. These stressors mainly include undernutrition or specific nutritional deficits, chronic behavioral stress, exposure to environmental chemicals, and pharmacological treatments that affect some important factors involved in renal physiology. We also discuss the common molecular mechanisms that are activated by the mentioned stressors and that promote the appearance of these adult diseases, with a brief description on some reprogramming strategies, which is a relatively new and promising field to treat or to prevent these diseases.

A maternal low-protein diet during gestation induces hepatic autophagy-related gene expression in a sex-specific manner in Sprague-Dawley rats

This study investigates the mechanism by which maternal protein restriction induces hepatic autophagy-related gene expression in the offspring of rats. Pregnant Sprague-Dawley rats were fed either a control diet (C, 18 % energy from protein) or a low-protein diet (LP, 8·5 % energy from protein) during gestation, followed by the control diet during lactation and post-weaning. Liver tissue was collected from the offspring at postnatal day 38 and divided into four groups according to sex and maternal diet (F-C, F-LP, M-C and M-LP) for further analysis. Autophagy-related mRNA and protein levels were determined by real-time PCR and Western blotting, respectively. In addition, chromatin immunoprecipitation (ChIP) was performed to investigate the interactions between transcription factors and autophagy-related genes. Protein levels of p- eukaryotic translation initiation factor 2a and activating transcription factor 4 (ATF4) were increased only in the female offspring born to dams fed the LP diet. Correlatively, the mRNA expression of hepatic autophagy-related genes including Map1lc3b, P62/Sqstm1, Becn1, Atg3, Atg7 and Atg10 was significantly greater in the F-LP group than in the F-C group. Furthermore, ChIP results showed greater ATF4 and C/EBP homology protein (CHOP) binding at the regions of a set of autophagy-related genes in the F-LP group than in the F-C group. Our data demonstrated that a maternal LP diet transcriptionally programmed hepatic autophagy-related gene expression only in female rat offspring. This transcriptional programme involved the activation of the eIF2α/ATF4 pathway and intricate regulation by transcription factors ATF4 and CHOP.

Maternal Low Volume Circulation Relates to Normotensive and Preeclamptic Fetal Growth Restriction

This narrative review summarizes current evidence on the association between maternal low volume circulation and poor fetal growth. Though much work has been devoted to the study of cardiac output and peripheral vascular resistance, a low intravascular volume may explain why high vascular resistance causes hypertension in women with preeclampsia (PE) that is associated with fetal growth restriction (FGR) and, at the same time, presents with normotension in FGR itself. Normotensive women with small for gestational age babies show normal gestational blood volume expansion superimposed upon a constitutionally low intravascular volume. Early onset preeclampsia (EPE; occurring before 32 weeks) is commonly associated with FGR, and poor plasma volume expandability may already be present before conception, thus preceding gestational volume expansion. Experimentally induced low plasma volume in rodents predisposes to poor fetal growth and interventions that enhance plasma volume expansion in FGR have shown beneficial effects on intrauterine fetal condition, prolongation of gestation and birth weight. This review makes the case for elevating the maternal intravascular volume with physical exercise with or without Nitric Oxide Donors in FGR and EPE, and evaluating its role as a potential target for prevention and/or management of these conditions.

Sex-specific mediating effect of gestational weight gain between pre-pregnancy body mass index and gestational diabetes mellitus

Background

Inappropriate weight gain may increase the risk of gestational diabetes mellitus (GDM). However, the relationship between pre-pregnancy body mass index (BMI), weight gain, and GDM has not been precisely quantified. This study aimed to explore whether gestational weight gain played a mediating role between pre-pregnancy BMI and GDM and whether the mediating effect was sex specific.

Methods

This study established a population-based observational cohort to assess weight gain in pregnant women. Mediation analyses were performed to quantify whether weight gain mediated the association between pre-pregnancy BMI and GDM.

Results

A total of 67,777 pregnant women were included in the final analysis, among whom 6751 (10.0%) were diagnosed with GDM. We verified that both pre-pregnancy BMI and weight gain were associated with GDM, and that BMI negatively contributed to weight gain. We also found that weight gain had a significant mediating effect on the relationship between pre-pregnancy BMI and GDM (Z_a × Z_b confidence intervals [CIs] 0.00234–0.00618). Furthermore, the effect was sex-specific, in that it was only significant in overweight women carrying female fetuses (Z_a × Z_b CIs 0.00422–0.01977), but not male fetuses (Z_a × Z_b CIs −0.00085 to 0.01236).

Conclusions

Weight gain during pregnancy had a fetal sex-specific mediating effect between pre-pregnancy BMI and GDM.

Are there sex differences in fetal growth strategies and in the long-term effects of pregnancy complications on cognitive functioning?

Males and females have been proposed to have different prenatal growth strategies, whereby males invest more in fetal growth and less in placental development, leaving them more susceptible to early-life adversity. We tested predictions of this hypothesis using data from the National Collaborative Perinatal Project. Male newborns were heavier than females, but there was no difference in placental weight, adjusting for birthweight. Among infants born prior to 33 weeks, the difference in birthweight between males and females was greater among those who did not survive than among those who did, potentially reflecting a strategy whereby males maintained growth in the face of prenatal insults, while females adjusted growth. However, there was no significant difference in mortality between the sexes. Being born small-for-gestational age or very preterm (prior to 33 weeks) was associated with significantly reduced performance for most of the cognitive traits examined at 7 years, although maternal preeclampsia was associated with reduced performance in fewer traits. Generally, these effects of early-life adversity (poor fetal growth, prematurity, and preeclampsia) did not differ between the sexes. However, analyzing the sexes separately (rather than testing the interaction between sex and adversity) resulted in numerous spurious sex-specific effects, whereby the effect of early-life adversity appeared to be significant in one sex but not the other. Overall, we found little support for the hypothesis that males prioritize growth more than females, and that this makes them more susceptible to early-life adversity. Furthermore, our results show that analyzing the sexes separately, rather than testing the adversity by sex interaction, can be highly misleading.

Aging-Related Behavioral, Adiposity, and Glucose Impairments and Their Association following Prenatal Alcohol Exposure in the C57BL/6J Mouse

People that experience prenatal alcohol exposure (PAE) may have behavioral and metabolic impairments, and it is unclear whether these remain stable or change with age. We assessed behavioral and metabolic endpoints across the lifespan in a mouse model of fetal alcohol spectrum disorder (FASD). Pregnant C57BL/6J mice received alcohol (ALC; 3 g/kg) or maltose-dextrin (control, CON) daily from embryonic day 8.5 to 17.5. Offspring were tested on accelerating rotarod, Y-maze, novel object recognition, and fear conditioning at 6 weeks and 10 and 17 months; females were also tested at 24 months. Body composition, fasting glucose, and glucose clearance were assessed at 18 months. Female but not male ALC mice had greater adiposity than age-matched CON from 7 months onward. At 18 months, male but not female ALC mice had reduced glucose clearance and ALC mice were more likely to have elevated fasting glucose. In the rotarod training session, ALC females performed worse than CON. In the Y-maze, significant exposure-age interactions affected ALC performance in both sexes versus age-match CON. For fear conditioning, all animals acquired the task and froze more at older ages. In both the context and cued tasks, there were exposure-age interactions and ALC animals frozen less than CON at 10 months. Correlation analysis revealed that fasting glucose and glucose clearance correlated with % of body fat in ALC but not in CON mice. Additionally, glucose intolerance and % body fat negatively correlated with performance in the rotarod, context learning, and novel object recognition tasks in ALC but not CON mice. All mice exhibit worsening of behavioral performance as they age, and PAE did not further exacerbate this. ALC but not CON mice displayed adiposity and glucose intolerance that correlate with their cognitive impairments, suggesting that these may be mechanistically related in PAE. Findings emphasize that FASD should be considered a whole-body disorder.

Prematurity and Low Birth Weight in Neonates as a Risk Factor for Obesity, Hypertension, and Chronic Kidney Disease in Pediatric and Adult Age

Low weight at birth may be due to intrauterine growth restriction or premature birth. Preterm birth is more common in low- and middle-income countries: 60% of preterm birth occur in sub-Saharan African or South Asian countries. However, in some higher-income countries, preterm birth rates appear to be increasing in relation to a reduction in the lower threshold of fetal viability. The cutoff is at 22–23 weeks, with a birth weight of approximately 500 g, although in developed countries such as Japan, the viability cutoff described is 21–22 weeks. There is evidence of the long-term consequences of prenatal programming of organ function and its relationship among adult diseases, such as hypertension (HT), central obesity, diabetes, metabolic syndrome, and chronic kidney disease (CKD). Premature delivery before the completion of nephrogenesis and intrauterine growth restriction leads to a reduction in the number of nephrons that are larger due to compensatory hyperfiltration and hypertrophy, which predisposes to the development of CKD in adulthood. In these patients, the long-term strategies are early evaluation and therapeutic interventions to decrease the described complications, by screening for HT, microalbuminuria and proteinuria, ultrasound monitoring, and renal function, with the emphasis on preventive measures. This review describes the effects of fetal programming on renal development and the risk of obesity, HT, and CKD in the future in patients with low birth weight (LBW), and the follow-up and therapeutic interventions to reduce these complications.

Sex-specific aging in animals: Perspective and future directions

Sex differences in aging occur in many animal species, and they include sex differences in lifespan, in the onset and progression of age-associated decline, and in physiological and molecular markers of aging. Sex differences in aging vary greatly across the animal kingdom. For example, there are species with longer-lived females, species where males live longer, and species lacking sex differences in lifespan. The underlying causes of sex differences in aging remain mostly unknown. Currently, we do not understand the molecular drivers of sex differences in aging, or whether they are related to the accepted hallmarks or pillars of aging or linked to other well-characterized processes. In particular, understanding the role of sex-determination mechanisms and sex differences in aging is relatively understudied. Here, we take a comparative, interdisciplinary approach to explore various hypotheses about how sex differences in aging arise. We discuss genomic, morphological, and environmental differences between the sexes and how these relate to sex differences in aging. Finally, we present some suggestions for future research in this area and provide recommendations for promising experimental designs.

Association of low birthweight and premature birth with hypertensive disorders in pregnancy: a systematic review and meta-analysis

BACKGROUND

Growing evidence suggests that women born preterm or small have an increased risk of experiencing hypertensive disorders during pregnancy; however, a quantitative summary of the evidence on this issue is unavailable.

OBJECTIVE

We aimed to systematically review the literature to describe the association between being born preterm, low birthweight (LBW), or small for gestational age (SGA), and future gestational hypertension, preeclampsia, or eclampsia.

METHODS

We searched the MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and ICTRP databases. We included all cohort and case-control studies examining the association between LBW, preterm birth, or SGA and hypertensive disorders in pregnancy. We pooled the odds ratios and 95% confidence intervals using the DerSimonian and Laird random-effects model. We assessed the certainty of evidence for each outcome using the Grading of Recommendations, Assessment, Development, and Evaluation criteria.

RESULTS

Eleven studies were identified, totalling 752 316 participants. Being born preterm, LBW, or SGA was associated with gestational hypertension [pooled odds ratio (OR), 1.31; 95% confidence interval (CI) 1.15-1.50; moderate certainty of evidence] and preeclampsia (pooled OR, 1.35; 95% CI 1.23-1.48; moderate certainty of evidence). No study measured eclampsia as an outcome.

CONCLUSION

Women born preterm, LBW, or SGA have an increased risk of gestational hypertension and preeclampsia. The course of the mother's own birth might be used to identify women at risk of gestational hypertension and preeclampsia.

IUGR with catch-up growth programs impaired insulin sensitivity through LRP6/IRS-1 in male rats

Intrauterine growth restriction combined with postnatal accelerated growth (CG-IUGR) could lead to long-term detrimental metabolic outcomes characterized by insulin resistance. As an indispensable co-receptor of Wnt signaling, LRP6 plays a critical role in the susceptibility of metabolic disorders. However, whether LRP6 is involved in the metabolic programing is still unknown. We hypothesized that CG-IUGR programed impaired insulin sensitivity through the impaired LRP6-mediated Wnt signaling in skeletal muscle. A CG-IUGR rat model was employed. The transcriptional and translational alterations of the components of the Wnt and the insulin signaling in the skeletal muscle of the male CG-IUGR rats were determined. The role of LRP6 on the insulin signaling was evaluated by shRNA knockdown or Wnt3a stimulation of LRP6. Compared with controls, the male CG-IUGR rats showed an insulin-resistant phenotype, with impaired insulin signaling and decreased expression of LRP6/β-catenin in skeletal muscle. LRP6 knockdown led to reduced expression of the IR-β/IRS-1 in C2C12 cell line, while Wnt3a-mediated LRP6 expression increased the expression of IRS-1 and IGF-1R but not IR-β in the primary muscle cells of male CG-IUGR rats. The impaired LRP6/β-catenin/IGF-1R/IRS-1 signaling is probably one of the critical mechanisms underlying the programed impaired insulin sensitivity in male CG-IUGR.

The Placenta's Role in Sexually Dimorphic Fetal Growth Strategies

Fetal sex affects the risk of pregnancy complications and the long-term effects of prenatal environment on health. Some have hypothesized that growth strategies differ between the sexes, whereby males prioritize growth whereas females are more responsive to their environment. This review evaluates the role of the placenta in such strategies, focusing on (1) mechanisms underlying sexual dimorphism in gene expression, (2) the nature and extent of sexual dimorphism in placental gene expression, (3) sexually dimorphic responses to nutrient supply, and (4) sexual dimorphism in morphology and histopathology. The sex chromosomes contribute to sex differences in placental gene expression, and fetal hormones may play a role later in development. Sexually dimorphic placental gene expression may contribute to differences in the prevalence of complications such as preeclampsia, although this link is not clear. Placental responses to nutrient supply frequently show sexual dimorphism, but there is no consistent pattern where one sex is more responsive. There are sex differences in the prevalence of placental histopathologies, and placental changes in pregnancy complications, but also many similarities. Overall, no clear patterns support the hypothesis that females are more responsive to the maternal environment, or that males prioritize growth. While male fetuses are at greater risk of a variety of complications, total prenatal mortality is higher in females, such that males exposed to early insults may be more likely to survive and be observed in studies of adverse outcomes. Going forward, robust statistical approaches to test for sex-dependent effects must be more widely adopted to reduce the incidence of spurious results.

Metabolic changes in female rats exposed to intrauterine Hyperglycemia and post-weaning consumption of high-fat diet

We evaluated the influence of the hyperglycemic intrauterine environment and post-weaning consumption of a high-fat diet on the glycemia, insulin, lipid and immunological profile of rat offspring in adulthood. Female rats received citrate buffer (Control - C) or Streptozotocin (a beta cell-cytotoxic drug to induce diabetes - D) on post-natal day 5. In adulthood, these rats were mated to obtain female offspring, who were fed a standard diet (SD) or high-fat diet (HFD) from weaning to adulthood (n = 10 rats/group). OC/SD and OC/HFD represent female offspring of control mothers and received SD or HFD, respectively; OD/SD and OD/HFD represent female offspring of diabetic mothers and received SD or HFD, respectively. At adulthood, the Oral Glucose Tolerance Test (OGTT) was performed and, next, the rats were anesthetized and euthanized. Pancreas was collected and analyzed, and adipose tissue was weighted. Blood samples were collected to determine biochemical and immunological profiles. The food intake was lower in HFD-fed rats and visceral fat weight was increased in the OD/HFD group. OC/HFD, OD/SD, and OD/HFD groups presented glucose intolerance and lower insulin secretion during OGTT. An impaired pancreatic beta-cell function was shown in the adult offspring of diabetic rats, regardless of diet. Interleukin (IL)-6 and IL-10 concentrations were lower in the OD/HFD group and associated to a low-grade inflammatory condition. The fetal programming was responsible for impaired beta cell function in experimental animals. The association of maternal diabetes and post-weaning high-fat diet is responsible for greater glucose intolerance, impaired insulin secretion and immunological change.

Epigenetic processes during preeclampsia and effects on fetal development and chronic health

Preeclampsia (PE), the leading cause of maternal and fetal morbidity and mortality, is associated with poor fetal growth, intrauterine growth restriction (IUGR) and low birth weight (LBW). Offspring of women who had PE are at increased risk for cardiovascular (CV) disease later in life. However, the exact etiology of PE is unknown. Moreover, there are no effective interventions to treat PE or alleviate IUGR and the developmental origins of chronic disease in the offspring. The placenta is critical to fetal growth and development. Epigenetic regulatory processes such as histone modifications, microRNAs and DNA methylation play an important role in placental development including contributions to the regulation of trophoblast invasion and remodeling of the spiral arteries. Epigenetic processes that lead to changes in placental gene expression in PE mediate downstream effects that contribute to the development of placenta dysfunction, a critical mediator in the onset of PE, impaired fetal growth and IUGR. Therefore, this review will focus on epigenetic processes that contribute to the pathogenesis of PE and IUGR. Understanding the epigenetic mechanisms that contribute to normal placental development and the initiating events in PE may lead to novel therapeutic targets in PE that improve fetal growth and mitigate increased CV risk in the offspring.

A Review of Biomechanics Analysis of the Umbilical-Placenta System With Regards to Diseases

Placenta is an important organ that is crucial for both fetal and maternal health. Abnormalities of the placenta, such as during intrauterine growth restriction (IUGR) and pre-eclampsia (PE) are common, and an improved understanding of these diseases is needed to improve medical care. Biomechanics analysis of the placenta is an under-explored area of investigation, which has demonstrated usefulness in contributing to our understanding of the placenta physiology. In this review, we introduce fundamental biomechanics concepts and discuss the findings of biomechanical analysis of the placenta and umbilical cord, including both tissue biomechanics and biofluid mechanics. The biomechanics of placenta ultrasound elastography and its potential in improving clinical detection of placenta diseases are also discussed. Finally, potential future work is listed.

Novel Role of Gestational Hydralazine in Limiting Maternal and Dietary Obesity-Related Chronic Kidney Disease

BACKGROUND

Maternal obesity is a risk factor for chronic kidney disease (CKD) in offspring, underpinning the theory of the developmental origins of health and disease. DNA methylation has been implicated in the programming of adult chronic disease by maternal obesity, therefore, DNA demethylating agents may mitigate offspring risk of disease. In rodent models, low-dose hydralazine has previously been shown to reduce renal fibrosis via DNA demethylation. We used mouse models of maternal obesity and offspring obesity to determine whether administration of low-dose hydralazine during gestation can prevent fetal programming of CKD in offspring.

METHODS

Female C57BL/6 mice received high fat diet (HFD) or chow prior to mating, during gestation and lactation. During gestation, dams received subcutaneous hydralazine (5 mg/kg) or saline thrice-weekly. Male offspring weaned to HFD or chow, which continued until endpoint at 32 weeks. Biometric and metabolic parameters, renal global DNA methylation, renal functional and structural changes, and renal markers of fibrosis, inflammation and oxidative stress were assessed at endpoint.

RESULTS

Offspring exposed to maternal obesity or diet-induced obesity had significantly increased renal global DNA methylation, together with other adverse renal effects including albuminuria, glomerulosclerosis, renal fibrosis, and oxidative stress. Offspring exposed to gestational hydralazine had significantly reduced renal global DNA methylation. In obese offspring of obese mothers, gestational hydralazine significantly decreased albuminuria, glomerulosclerosis, and serum creatinine. Obese offspring of hydralazine-treated lean mothers displayed reduced markers of renal fibrosis and oxidative stress.

CONCLUSION

Gestational hydralazine decreased renal global DNA methylation and exerted renoprotective effects in offspring. This supports a potential therapeutic effect of hydralazine in preventing maternal obesity or dietary obesity-related CKD, through an epigenetic mechanism.

Placental insufficiency induces a sexually dimorphic response in the expression of cardiac growth and metabolic signalling molecules upon exposure to a postnatal western diet in guinea pigs

There is a strong relationship between low birth weight (LBW) and an increased risk of developing cardiovascular disease (CVD). In postnatal life, LBW offspring are becoming more commonly exposed to the additional independent CVD risk factors, such as an obesogenic diet. However, how an already detrimentally programmed LBW myocardium responds to a secondary insult, such as an obesogenic diet (western diet; WD), during postnatal life is ill defined. Herein, we aimed to determine in a pre-clinical guinea pig model of CVD, both the independent and interactive effects of LBW and a postnatal WD on the molecular pathways that regulate cardiac growth and metabolism. Uterine artery ablation was used to induce placental insufficiency (PI) in pregnant guinea pigs to generate LBW offspring. Normal birth weight (NBW) and LBW offspring were weaned onto either a Control diet or WD. At ˜145 days after birth (young adulthood), male and female offspring were humanely killed, the heart weighed and left ventricle tissue collected. The mRNA expression of signalling molecules involved in a pathological hypertrophic and fibrotic response was increased in the myocardium of LBW male, but not female offspring, fed a WD as was the mRNA expression of transcription factors involved in fatty acid oxidation. The mRNA expression of glucose transporters was downregulated by LBW and WD in male, but not female hearts. This study has highlighted a sexually dimorphic cardiac pathological hypertrophic and fibrotic response to the secondary insult of postnatal WD consumption in LBW offspring.

Maternal Childhood Adversity as a Risk for Perinatal Complications and NICU Hospitalization

OBJECTIVE

To examine maternal childhood adversity in relation to increased risk for maternal and infant perinatal complications and newborn Neonatal Intensive Care Unit (NICU) admittance.

METHODS

A sample of 164 women recruited at their first prenatal appointment participated in a longitudinal study through 6 weeks postdelivery. Participants self-reported on their adverse childhood experiences (ACEs), negative health risks (overweight/obesity, smoking, and alcohol use), adverse infant outcomes, NICU admittance, and maternal perinatal complications across three pregnancy assessments and one post-birth assessment. Logistic binomial regression analyses were used to examine associations between maternal ACEs and adverse infant outcomes, NICU admittance, and maternal perinatal complications, controlling for pregnancy-related health risks.

RESULTS

Findings showed that women with severe ACEs exposure (6+ ACEs) had 4 times the odds of reporting at least one adverse infant outcome (odds ratio [OR] = 4.33, 95% CI: 1.02-18.39), almost 9 times the odds of reporting a NICU admission (OR = 8.70, 95% CI: 1.34-56.65), and 4 times the odds of reporting at least one maternal perinatal outcome (OR = 4.37, 95% CI: 1.43-13.39).

CONCLUSIONS

The findings demonstrate the extraordinary risk that mothers' ACEs pose for infant and maternal health outcomes over and above the associations with known maternal health risks during pregnancy, including overweight/obesity, smoking, and alcohol use. These results support a biological intergenerational transmission framework, which suggests that risk from maternal adversity is perpetuated in the next generation through biophysical and behavioral mechanisms during pregnancy that negatively affect infant health outcomes.

Preeclampsia and Cardiovascular Risk for Offspring

There is growing evidence of long-term cardiovascular sequelae in children after in utero exposure to preeclampsia. Maternal hypertension and/or placental ischaemia during pregnancy increase the risk of hypertension, stroke, diabetes, and cardiovascular disease (CVD) in the offspring later in life. The mechanisms associated with CVD seem to be a combination of genetic, molecular, and environmental factors which can be defined as fetal and postnatal programming. The aim of this paper is to discuss the relationship between pregnancy complicated by preeclampsia and possibility of CVD in the offspring. Unfortunately, due to its multifactorial nature, a clear dependency mechanism between preeclampsia and CVD is difficult to establish.

Current State of Preeclampsia Mouse Models: Approaches, Relevance, and Standardization

Preeclampsia (PE) is a multisystemic, pregnancy-specific disorder and a leading cause of maternal and fetal death. PE is also associated with an increased risk for chronic morbidities later in life for mother and offspring. Abnormal placentation or placental function has been well-established as central to the genesis of PE; yet much remains to be determined about the factors involved in the development of this condition. Despite decades of investigation and many clinical trials, the only definitive treatment is parturition. To better understand the condition and identify potential targets preclinically, many approaches to simulate PE in mice have been developed and include mixed mouse strain crosses, genetic overexpression and knockout, exogenous agent administration, surgical manipulation, systemic adenoviral infection, and trophoblast-specific gene transfer. These models have been useful to investigate how biological perturbations identified in human PE are involved in the generation of PE-like symptoms and have improved the understanding of the molecular mechanisms underpinning the human condition. However, these approaches were characterized by a wide variety of physiological endpoints, which can make it difficult to compare effects across models and many of these approaches have aspects that lack physiological relevance to this human disorder and may interfere with therapeutic development. This report provides a comprehensive review of mouse models that exhibit PE-like symptoms and a proposed standardization of physiological characteristics for analysis in murine models of PE.

Calcium-Deficiency during Pregnancy Affects Insulin Resistance in Offspring

Prenatal malnutrition is known to affect the phenotype of the offspring through changes in epigenetic regulation. Growing evidence suggests that epigenetics is one of the mechanisms by which nutrients and minerals affect metabolic traits. Although the perinatal period is the time of highest phenotypic plasticity, which contributes largely to developmental programming, there is evidence of nutritional influence on epigenetic regulation during adulthood. Calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. Cortisol, the most important glucocorticoid, is considered to lead to insulin resistance and metabolic syndrome. 11β-hydroxysteroid dehydrogenase-1 is a key enzyme that catalyzes the intracellular conversion of cortisone to physiologically active cortisol. This brief review aims to identify the effects of Ca deficiency during pregnancy and/or lactation on insulin resistance in the offspring. Those findings demonstrate that maternal Ca deficiency during pregnancy may affect the epigenetic regulation of gene expression and thereby induce different metabolic phenotypes. We aim to address the need for Ca during pregnancy and propose the scaling-up of clinical and public health approaches that improved pregnancy outcomes.

Intergenerational effects of the antioxidant Idebenone on the placentas of rats with gestational diabetes mellitus

Experimental models of maternal diabetes lead to the intrauterine programming of Gestational Diabetes Mellitus (GDM) in the offspring, together with an intrauterine proinflammatory environment, feto-placental metabolic alterations and fetal overgrowth. The aim of this work was to evaluate the effect of the mitochondrial antioxidant Idebenone given to F0 mild pregestational diabetic rats on the development of GDM in their F1 offspring and the intergenerational programming of a pro-oxidant/proinflammatory environment that affects the placentas of F2 fetuses. Control and mild pregestational diabetic female rats (F0) were mated with control males, and Idebenone or vehicle was administered to diabetic rats from day 1 of gestation to term. The F1 female offspring were mated with control males and maternal and fetal plasma samples were obtained for metabolic determinations at term. The F2 fetuses and placentas were weighed, and placental protein levels and peroxynitrite-induced damage (immunohistochemistry), mRNA levels (PCR), nitric oxide production (Griess reaction), and number of apoptotic cells (TUNEL) were evaluated. The F1 offspring of F0 diabetic rats (treated or not with Idebenone) developed GDM. The placentas of GDM rats showed a decrease in the mRNA levels of manganese superoxide dismutase and an increase in the production of nitric oxide, peroxynitrite-induced damage, and connective tissue growth factor levels, alterations that were prevented by the maternal Idebenone treatment in F0 rats. In conclusion, the maternal treatment with Idebenone in pregestational diabetic F0 rats ameliorates the pro-oxidant/proinflammatory environment that affects the placentas of F2 fetuses, although it does not prevent F1 rats from developing GDM.

Sex-dependent vulnerability of fetal nonhuman primate cardiac mitochondria to moderate maternal nutrient reduction

Poor maternal nutrition in pregnancy affects fetal development, predisposing offspring to cardiometabolic diseases. The role of mitochondria during fetal development on later-life cardiac dysfunction caused by maternal nutrient reduction (MNR) remains unexplored. We hypothesized that MNR during gestation causes fetal cardiac bioenergetic deficits, compromising cardiac mitochondrial metabolism and reserve capacity. To enable human translation, we developed a primate baboon model (Papio spp.) of moderate MNR in which mothers receive 70% of control nutrition during pregnancy, resulting in intrauterine growth restriction (IUGR) offspring and later exhibiting myocardial remodeling and heart failure at human equivalent ∼25 years. Term control and MNR baboon offspring were necropsied following cesarean-section, and left ventricle (LV) samples were collected. MNR adversely impacted fetal cardiac LV mitochondria in a sex-dependent fashion. Increased maternal plasma aspartate aminotransferase, creatine phosphokinase (CPK), and elevated cortisol levels in MNR concomitant with decreased blood insulin in male fetal MNR were measured. MNR resulted in a two-fold increase in fetal LV mitochondrial DNA (mtDNA). MNR resulted in increased transcripts for several respiratory chain (NDUFB8, UQCRC1, and cytochrome c) and adenosine triphosphate (ATP) synthase proteins. However, MNR fetal LV mitochondrial complex I and complex II/III activities were significantly decreased, possibly contributing to the 73% decreased ATP content and increased lipid peroxidation. MNR fetal LV showed mitochondria with sparse and disarranged cristae dysmorphology. Conclusion: MNR disruption of fetal cardiac mitochondrial fitness likely contributes to the documented developmental programming of adult cardiac dysfunction, indicating a programmed mitochondrial inability to deliver sufficient energy to cardiac tissues as a chronic mechanism for later-life heart failure.

Exercise alters cardiovascular and renal pregnancy adaptations in female rats born small on a high-fat diet

Intrauterine growth restriction programs adult cardiorenal disease, which may be exacerbated by pregnancy and obesity. Importantly, exercise has positive cardiovascular effects. This study determined if high-fat feeding exacerbates the known adverse cardiorenal adaptations to pregnancy in rats born small and whether endurance exercise can prevent these complications. Uteroplacental insufficiency was induced by bilateral uterine vessel ligation (Restricted) or sham (Control) surgery on embryonic day 18 (E18) in Wistar-Kyoto rats. Female offspring consumed a Chow or high-fat diet (HFD) from weaning and were randomly allocated to either a sedentary (Sedentary) or an exercise protocol at 16 wk; exercised before and during pregnancy (Exercise), or exercised during pregnancy only (PregEx). Systolic blood pressure was measured prepregnancy and rats were mated at 20 wk. During pregnancy, systolic blood pressure (E18) and renal function (E19) were assessed. Sedentary HFD Control females had increased estimated glomerular filtration rate (eGFR) compared with Chow. Compared with Control, Sedentary-Restricted females had increased eGFR, which was not influenced by HFD. Renal function was not affected by exercise and prepregnancy blood pressure was not altered. Restricted Chow-fed dams and dams fed a high-fat diet had a greater reduction in systolic blood pressure during late gestation, which was only prevented by Exercise. In summary, high-fat fed females born small are at a greater risk of altered cardiorenal adaptations to pregnancy. Although cardiovascular dysfunction was prevented by Exercise, renal dysfunction was not affected by exercise interventions. This study highlights that modifiable risk factors can have beneficial effects in the mother during pregnancy, which may impact fetal growth and development.

Low-dose hydralazine during gestation reduces renal fibrosis in rodent offspring exposed to maternal high fat diet

BACKGROUND

Maternal high fat diet (HFD) promotes chronic kidney disease (CKD) in offspring. This is in accordance with the theory of fetal programming, which suggests adverse conditions occurring in utero predispose offspring to chronic conditions later in life. DNA methylation has been proposed as a key mechanism by which fetal programming occurs and is implicated in CKD progression. DNA demethylating drugs may interrupt the fetal programming of CKD by maternal obesity. Hydralazine, an antihypertensive agent, demethylates DNA at low doses which do not reduce blood pressure. We used a mouse model of maternal obesity to determine whether gestational administration of low-dose hydralazine to mothers can prevent CKD in offspring.

METHODS

C57BL/6 dams received HFD or chow from 6 weeks prior to mating and were administered subcutaneous hydralazine (5mg/kg) or saline thrice weekly during gestation. Male offspring were weaned to chow and were sacrificed at either postnatal week 9 or week 32. Biometric and metabolic parameters, renal global DNA methylation, renal structural and functional changes and markers of fibrosis, oxidative stress and inflammation were measured in offspring at weeks 9 and 32.

RESULTS

In week 9 offspring, maternal HFD consumption did not significantly alter anthropometric or metabolic parameters, or renal global DNA methylation. Week 32 offspring had increased renal global DNA methylation, together with albuminuria, glomerulosclerosis, renal fibrosis and oxidative stress. Administration of low-dose hydralazine to obese mothers during gestation reduced renal global DNA methylation and renal fibrotic markers in week 32 offspring.

CONCLUSION

Gestational hydralazine reduced renal global DNA methylation in offspring of obese mothers and attenuated maternal obesity-induced renal fibrosis. These data support the use of low-dose hydralazine as a demethylating agent to prevent CKD arising in offspring due to maternal HFD consumption.

Early life programming of adult ischemic heart disease within and across generations: The role of the socioeconomic context

BACKGROUND

The developmental origins of ischemic heart disease (IHD) have been widely documented but little is known about their persistence across more than one generation. This study aimed to investigate whether the effects of early life disadvantages on adult IHD have changed between generations and are mediated by adult socioeconomic circumstances, and further explore the transgenerational effects of grandparental and parental exposures to disadvantaged circumstances on adult offspring's IHD.

METHODS

We used register-based data from the Uppsala Multigenerational Study, Sweden. The study populations were the parents born 1915-1929 and their offspring born 1932-1972 with available obstetric data. The offspring were further linked to grandparents who had their socioeconomic and demographic data recorded. The outcome was incident IHD assessed at ages 32-75 during a follow-up from January 1, 1964 till December 31, 2008. The exposures included birthweight standardized-for-gestational age, ponderal index, gestational length, and parental socioeconomic position (SEP). Education and income were analyzed as mediators. Potential transgenerational associations were explored by linking offspring IHD to parents' standardized birthweight and gestational length, grandparental SEP, and to grandmothers' age, parity, and marital status at parental birth. All associations were examined in Cox proportional hazard regression models.

RESULTS

Lower standardized birthweight and lower parental SEP were found to be associated with higher IHD rates in both generations, with no evidence of effect modification by generation. Education and income did not mediate the association between standardized birthweight and IHD. Disadvantaged grandparental SEP, younger and older childbearing ages of grandmothers, and paternal preterm birth affected offspring's IHD independent of parental education, income, or IHD history.

CONCLUSIONS

The findings point to similar magnitudes of IHD inequalities by early life disadvantages across two historical periods and the existence of transgenerational effects on IHD. Epigenetic dysregulation involving the germline is a plausible candidate mechanism underlying the transgenerational associations that warrant further research.

Placental mitochondrial function in response to gestational exposures

Poor environmental conditions, including malnutrition, hypoxia and obesity in the mother increase the risk of pregnancy complications, such as pre-eclampsia and gestational diabetes mellitus, which impacts the lifelong health of the mother and her offspring. The placenta plays an important role in determining pregnancy outcome by acting as an exchange interface and endocrine hub to support fetal growth. Mitochondria are energy powerhouses of cells that fuel placental physiology throughout pregnancy, including placental development, substrate exchange and hormone secretion. They are responsive to environmental cues and changes in mitochondrial function may serve to mediate or mitigate the impacts of poor gestational environments on placental physiology and hence, the risks of pregnancy complications. Thus, a more integrated understanding about the role of placental mitochondria in orchestrating changes in relation to environmental conditions and pregnancy outcome is paramount. This review summarises the functions of mitochondria in the placenta and findings from humans and experimental animals that demonstrate how mitochondrial structure and function are altered in different gestational environments (namely complicated pregnancies and adverse environmental conditions). Together the available data suggest that mitochondria in the placenta play a major role in determining placental physiology, fetal growth and pregnancy outcome.

Ouabain Protects Nephrogenesis in Rats Experiencing Intrauterine Growth Restriction and Partially Restores Renal Function in Adulthood

Intrauterine growth restriction (IUGR) is, in general, accompanied by a reduction of the nephron number, which increases the risk of hypertension and renal dysfunction. Studies have revealed that ouabain can partially restore the number of nephrons during IUGR. However, there is limited information regarding the melioration of nephric structure and function. We used maternal malnutrition to induce an IUGR model in rats. Subsequently, we used a mini-pump to administer ouabain to IUGR rats during pregnancy. Male offspring were divided randomly into two groups. One group was fed a normal diet, whereas the other was fed an isocaloric 8% high-salt diet. Maternal malnutrition led to a reduction in the birth weight and number of nephrons in offspring. At the end of a 40-week follow-up period, offspring from the IUGR group had high blood pressure and abnormal excretion of urinary protein; these parameters were exacerbated in offspring fed a high-salt diet. However, ouabain administration during pregnancy could partially restore the number of nephrons in IUGR offspring, normalize blood pressure, and reduce urinary protein excretion, even when challenged with a high-salt diet. Pathology findings revealed that IUGR, particularly following feeding of a high-salt diet, damaged the ultrastructure of glomeruli, but these harmful effects were ameliorated in offspring treated with ouabain. Collectively, our data suggest that ouabain could rescue nephrogenesis in IUGR newborns and protect (at least in part) the structure and function of the kidney during adulthood even when encountering unfavorable environmental challenges in subsequent life.