Vernix caseosa reveals mechanistic clues linking maternal obesity to atopic dermatitis pathogenesis.

BACKGROUND: Maternal overweight and obesity have been associated with an increased risk of atopic dermatitis (AD) in the offspring, but the underlying mechanisms are unclear. Vernix caseosa (VC) is a proteolipid material covering the fetus produced during skin development. However, whether maternal prepregnancy weight excess influences fetal skin development is unknown. Characterizing the VC of newborns from mothers with prepregnancy overweight and obesity might reveal AD-prone alterations during fetal skin development. OBJECTIVE: We sought to explore AD biomarkers and staphylococcal loads in VC from the offspring of mothers who were overweight/obese (O/O) before pregnancy versus in those from offspring of normal weight mothers. METHODS: The VC of newborns of 14 O/O and 12 normal weight mothers were collected immediately after birth. Biomarkers were determined by ELISA and staphylococcal species by quantitative PCR. RESULTS: The VC from the O/O group showed decreased expression of skin barrier proteins (filaggrin and loricrin) and increased levels of proinflammatory biomarkers (IgA, thymic stromal lymphopoietin [TSLP], S100A8, IL-25, and IL-33). No differences in concentrations of antimicrobial peptides and enzymes were detected. The VC from the O/O group had a lower Staphylococcus epidermidis and Staphylococcus hominis commensal bacterial load, whereas Staphylococcus aureus bacterial load was not significantly different between the 2 groups. Maternal body mass index was negatively correlated with VC filaggrin expression and S epidermidis load and was positively associated with TSLP concentration. One-year follow-up established that the offspring of O/O mothers had a higher incidence of AD that was specifically linked with decreased VC filaggrin expression and lower S epidermidis load. CONCLUSIONS: VC from neonates of mothers with prepregnancy overweight and obesity exhibit skin barrier molecular alterations and staphylococcal dysbiosis that suggest early mechanistic clues to this population's increased risk of AD.

Asthma, obesity, and microbiota: A complex immunological interaction.

Obesity and allergic asthma are inflammatory chronic diseases mediated by distinct immunological features, obesity presents a Th1/Th17 profile, asthma is commonly associated with Th2 response. However, when combined, they result in more severe asthma symptoms, greater frequency of exacerbation episodes, and lower therapy responsiveness. These features lead to decreased life quality, associated with higher morbidity/mortality rates.  In addition, obesity prompts specific asthma phenotypes, which can be dependent on atopic status, age, and gender. In adults, obesity is associated with neutrophilic/Th17 profile, while in children, the outcome is diverse, in some cases children with obesity present aggravation of atopy, and Th2 inflammation, and in others an association with a Th1 profile, with reduced IgE levels and eosinophilia. These alterations occur due to a complex group of factors among which the microbiome has been recently explored. Particularly, evidence shows its important role in susceptibility or resistance to asthma development, via gut-lung-axis, and demonstrates its relevance to the immune pathogenesis of the syndrome. Few studies address the relevance of the lung microbiome in shaping the immune response, locally. However, specific bacteria, like Moraxella catarrhalis, Haemophilus influenza, and Streptococcus pneumoniae, correlate with important features of the obese-asthmatic phenotype. Although maternal obesity is known to increase asthma risk in offspring, the impact on lung colonization is unknown. This review details the main key immune mechanisms involved in obesity-aggravated asthma, featuring the effect of maternal obesity in the establishment of gut and lung microbiota of the offspring, acting as potential childhood asthma inducer.

The programming of kidney injury in offspring affected by maternal overweight and obesity: role of lipid accumulation, inflammation, oxidative stress, and fibrosis in the kidneys of offspring.

Maternal overweight and obesity are considered important factors affecting fetal development with many potential consequences for offspring after delivery, including the increased risk of obesity and diabetes mellitus. Maternal obesity promotes adiposity in the offspring by increasing fat deposition and expansion in the body of the offspring. The expansion of adipose tissue changes adipokine levels, including a decrease in adiponectin and an increase in leptin. In addition to changes in adipokine levels, there are also increases in pro-inflammatory cytokines, pro-fibrotic cytokines, and reactive oxygen species, leading to oxidative stress in the offspring. These contribute to the promotion of insulin resistance in offspring, which is associated with kidney injury. Interestingly, maternal obesity can also promote renal lipid accumulation, which could activate inflammatory processes and promote renal oxidative stress and renal fibrosis. These alterations in the kidneys of the offspring imply that a mother being overweight/obese can program the development of kidney disease in offspring. This review will discuss the effects of a mother being overweight or obese on their offspring and the consequences with regard to the kidneys of their offspring. With a focus on the molecular mechanisms, including renal inflammation, renal oxidative stress, renal fibrosis, and renal lipid metabolism in offspring born to overweight and obese mothers, the causative mechanisms and perspective of these conditions will be included.

Insulin Increases Adipose Adiponectin in Pregnancy by Inhibiting Ubiquitination and Degradation: Impact of Obesity.

CONTEXT: Circulating adiponectin levels are decreased in pregnant women with obesity or gestational diabetes, and this is believed to contribute to the insulin resistance and increased risk of fetal overgrowth associated with these conditions. However, the molecular mechanisms regulating adiponectin secretion from maternal adipose tissues in pregnancy are poorly understood. OBJECTIVE: We tested the hypothesis that obesity in pregnancy is associated with adipose tissue insulin resistance and increased adiponectin ubiquitination and degradation, caused by inflammation and endoplasmic reticulum (ER) stress. METHODS: Visceral adipose tissues were collected from lean and obese pregnant humans and mice. Total and ubiquitinated adiponectin, and markers of inflammation, ER stress, and insulin resistance were examined in adipose tissues. The role of insulin, inflammation, and ER stress in mediating adiponectin ubiquitination and degradation was examined using 3T3L-1 adipocytes. RESULTS: Obesity in pregnancy is associated with adipose tissue inflammation, ER stress, insulin resistance, increased adiponectin ubiquitination, and decreased total abundance of adiponectin. Adiponectin ubiquitination was increased in visceral fat of obese pregnant women as compared to lean pregnant women. We further observed that insulin prevents, whereas ER stress and inflammation promote, adiponectin ubiquitination and degradation in differentiated 3T3-L1 adipocytes. CONCLUSION: We have identified adiponectin ubiquitination as a key mechanism by which obesity diminishes adiponectin secretion in pregnancy. This information will help us better understand the mechanisms controlling maternal insulin resistance and fetal growth in pregnancy and may provide a foundation for the development of strategies aimed at improving adiponectin production in pregnant women with obesity or gestational diabetes.

Maternal obesity and stillbirth at term; placental pathology-A case control study.

OBJECTIVE: The aim was to explore the potential role of the placenta for the risk of stillbirth at term in pregnancies of obese women. METHODS: This was a case-control study comparing placental findings from term stillbirths with placental findings from live born infants. Cases were singleton term stillbirths to normal weight or obese women, identified in the Stockholm stillbirth database, n = 264 and n = 87, respectively. Controls were term singletons born alive to normal weight or obese women, delivered between 2002-2005 and between 2018-2019. Placentas were compared between women with stillborn and live-born infants, using logistic regression analyses. RESULTS: A long and hyper coiled cord, cord thrombosis and velamentous cord insertion were stronger risk factors for stillbirth in obese women compared to normal weight women. When these variables were adjusted for in the logistic regression analysis, also adjusted for potential confounders, the odds ratio for stillbirth in obese women decreased from 1.89 (CI 1.24-2.89) to 1.63 (CI 1.04-2.56). CONCLUSION: Approximately one fourth of the effect of obesity on the risk of stillbirth in term pregnancies is explained by umbilical cord associated pathology.

High-fiber diet mitigates maternal obesity-induced cognitive and social dysfunction in the offspring via gut-brain axis.

Maternal obesity has been reported to be related to neurodevelopmental disorders in the offspring. However, the underlying mechanisms and effective interventions remain unclear. This cross-sectional study with 778 children aged 7-14 years in China indicated that maternal obesity is strongly associated with children's lower cognition and sociality. Moreover, it has been demonstrated that maternal obesity in mice disrupted the behavior and gut microbiome in offspring, both of which were restored by a high-fiber diet in either dams or offspring via alleviating synaptic impairments and microglial maturation defects. Co-housing and feces microbiota transplantation experiments revealed a causal relationship between microbiota and behavioral changes. Moreover, treatment with the microbiota-derived short-chain fatty acids also alleviated the behavioral deficits in the offspring of obese dams. Together, our study indicated that the microbiota-metabolites-brain axis may underlie maternal obesity-induced cognitive and social dysfunctions and that high dietary fiber intake could be a promising intervention.

Maternal obesity during pregnancy leads to adipose tissue ER stress in mice via miR-126-mediated reduction in Lunapark.

AIMS/HYPOTHESIS: Levels of the microRNA (miRNA) miR-126-3p are programmed cell-autonomously in visceral adipose tissue of adult offspring born to obese female C57BL/6J mice. The spectrum of miR-126-3p targets and thus the consequences of its dysregulation for adipocyte metabolism are unknown. Therefore, the aim of the current study was to identify novel targets of miR-126-3p in vitro and then establish the outcomes of their dysregulation on adipocyte metabolism in vivo using a well-established maternal obesity mouse model. METHODS: miR-126-3p overexpression in 3T3-L1 pre-adipocytes followed by pulsed stable isotope labelling by amino acids in culture (pSILAC) was performed to identify novel targets of the miRNA. Well-established bioinformatics algorithms and luciferase assays were then employed to confirm those that were direct targets of miR-126-3p. Selected knockdown experiments were performed in vitro to define the consequences of target dysregulation. Quantitative real-time PCR, immunoblotting, histology, euglycaemic-hyperinsulinaemic clamps and glucose tolerance tests were performed to determine the phenotypic and functional outcomes of maternal programmed miR-126-3p levels in offspring adipose tissue. RESULTS: The proteomic approach confirmed the identity of known targets of miR-126-3p (including IRS-1) and identified Lunapark, an endoplasmic reticulum (ER) protein, as a novel one. We confirmed by luciferase assay that Lunapark was a direct target of miR-126-3p. Overexpression of miR-126-3p in vitro led to a reduction in Lunapark protein levels and increased Perk (also known as Eif2ak3) mRNA levels and small interference-RNA mediated knockdown of Lunapark led to increased Xbp1, spliced Xbp1, Chop (also known as Ddit3) and Perk mRNA levels and an ER stress transcriptional response in 3T3-L1 pre-adipocytes. Consistent with the results found in vitro, increased miR-126-3p expression in adipose tissue from adult mouse offspring born to obese dams was accompanied by decreased Lunapark and IRS-1 protein levels and increased markers of ER stress. At the whole-body level the animals displayed glucose intolerance. CONCLUSIONS/INTERPRETATION: Concurrently targeting IRS-1 and Lunapark, a nutritionally programmed increase in miR-126-3p causes adipose tissue insulin resistance and an ER stress response, both of which may contribute to impaired glucose tolerance. These findings provide a novel mechanism by which obesity during pregnancy leads to increased risk of type 2 diabetes in the offspring and therefore identify miR-126-3p as a potential therapeutic target.

Maternal Obesity Influences Placental Nutrient Transport, Inflammatory Status, and Morphology in Human Term Placenta.

CONTEXT: Maternal obesity has a significant impact on placental development. However, this impact on the placenta's structure and function (ie, nutrient transport and hormone and cytokine production) is a controversial subject. OBJECTIVE: We hypothesized that maternal obesity is associated with morphologic, secretory, and nutrient-related changes and elevated levels of inflammation in the placenta. DESIGN: We collected samples of placental tissue from 2 well-defined groups of pregnant women from 2017 to 2019. We compared the 2 groups regarding placental cytokine and hormone secretion, immune cell content, morphology, and placental nutrient transporter expressions. SETTING: Placenta were collected after caesarean section performed by experienced clinicians at Centre Hospitalier Intercommunal (CHI) of Poissy-Saint-Germain-en-Laye. PATIENTS: The main inclusion criteria were an age between 27 and 37 years old, no complications of pregnancy, and a first-trimester body mass index of 18-25 kg/m2 for the nonobese (control) group and 30-40 kg/m2 for the obese group. RESULTS: In contrast to our starting hypothesis, we observed that maternal obesity was associated with (1) lower placental IL-6 expression and macrophage/leukocyte infiltration, (2) lower placental expression of GLUT1 and SNAT1-2, (3) a lower placental vessel density, and (4) lower levels of placental leptin and human chorionic gonadotropin production. CONCLUSION: These results suggest that the placenta is a plastic organ and could optimize fetal growth. A better understanding of placental adaptation is required because these changes may partly determine the fetal outcome in cases of maternal obesity.

A heretical view: rather than a solely placental protective function, placental 11ß hydroxysteroid dehydrogenase 2 also provides substrate for fetal peripheral cortisol synthesis in obese pregnant ewes.

Exposure to glucocorticoid levels higher than appropriate for current developmental stages induces offspring metabolic dysfunction. Overfed/obese (OB) ewes and their fetuses display elevated blood cortisol, while fetal Adrenocorticotropic hormone (ACTH) remains unchanged. We hypothesized that OB pregnancies would show increased placental 11ß hydroxysteroid dehydrogenase 2 (11ß-HSD2) that converts maternal cortisol to fetal cortisone as it crosses the placenta and increased 11ß-HSD system components responsible for peripheral tissue cortisol production, providing a mechanism for ACTH-independent increase in circulating fetal cortisol. Control ewes ate 100% National Research Council recommendations (CON) and OB ewes ate 150% CON diet from 60 days before conception until necropsy at day 135 gestation. At necropsy, maternal jugular and umbilical venous blood, fetal liver, perirenal fat, and cotyledonary tissues were harvested. Maternal plasma cortisol and fetal cortisol and cortisone were measured. Fetal liver, perirenal fat, cotyledonary 11ß-HSD1, hexose-6-phosphate dehydrogenase (H6PD), and 11ß-HSD2 protein abundance were determined by Western blot. Maternal plasma cortisol, fetal plasma cortisol, and cortisone were higher in OB vs. CON (p < 0.01). 11ß-HSD2 protein was greater (p < 0.05) in OB cotyledonary tissue than CON. 11ß-HSD1 abundance increased (p < 0.05) in OB vs. CON fetal liver and perirenal fat. Fetal H6PD, an 11ß-HSD1 cofactor, also increased (p < 0.05) in OB vs. CON perirenal fat and tended to be elevated in OB liver (p < 0.10). Our data provide evidence for increased 11ß-HSD system components responsible for peripheral tissue cortisol production in fetal liver and adipose tissue, thereby providing a mechanism for an ACTH-independent increase in circulating fetal cortisol in OB fetuses.

Single-cell transcriptome analysis reveals that maternal obesity affects DNA repair, histone methylation, and autophagy level in mouse embryos.

Obesity causes many reproductive dysfunctions such as reduced conception, infertility, and early pregnancy loss, and this is largely due to the negative effects of obesity on oocyte and embryo quality. In the present study, we employed single-cell RNA transcriptome sequencing to investigate the potential causes for the maternal obesity effects on mouse embryos. Our results showed that the 4-cell and morula/blastocyst rates were all significantly decreased during embryo development in obese mice. Genome-wide analysis indicated that obesity altered the expression of more than 1100 genes in 2-cell embryos, including the genes which were related to the p53 signaling pathway and apoptosis. Further analysis showed that the expression of 47 genes related to DNA damage was changed, and a positive γH2A signal and the altered expression of Rad51 and Tex15 were observed in the obese embryos. Obesity also affected histone methylation, shown by the decrease of the H3K4-me2 level. Besides this, we observed the occurrence of autophagy and apoptosis in the embryos of obese mice. There were 42 genes that were related to autophagy/apoptosis that showed aberrant expression, and the positive LC3 signal and the decrease of Clec16a, Rraga, and Atg10 level were also observed. In summary, our study suggested that obesity affected early embryonic development by inducing DNA damage, aberrant histone methylation, and autophagy levels in mice.

Relative Contribution of Gestational Weight Gain, Gestational Diabetes, and Maternal Obesity to Neonatal Fat Mass.

Maternal nutritional and metabolic status influence fetal growth. This study investigated the contribution of gestational weight gain (GWG), gestational diabetes (GDM), and maternal obesity to birthweight and newborn body fat. It is a secondary analysis of a prospective study including 204 women with a pregestational body mass index (BMI) of 18.5-24.9 kg/m2 and 219 women with BMI ≥ 30 kg/m2. GDM was screened in the second and third trimester and was treated by dietary intervention, and insulin if required. Maternal obesity had the greatest effect on skinfolds (+1.4 mm) and cord leptin (+3.5 ng/mL), but no effect on birthweight. GWG was associated with increased birthweight and skinfolds thickness, independently from GDM and maternal obesity. There was an interaction between third trimester weight gain and GDM on birthweight and cord leptin, but not with maternal obesity. On average, +1 kg in third trimester was associated with +13 g in birthweight and with +0.64 ng/mL in cord leptin, and a further 32 g and 0.89 ng/mL increase in diabetic mothers, respectively. Maternal obesity is the main contributor to neonatal body fat. There is an independent association between third trimester weight gain, birthweight, and neonatal body fat, enhanced by GDM despite intensive treatment.

Parental SIRT1 Overexpression Attenuate Metabolic Disorders Due to Maternal High-Fat Feeding.

Maternal obesity can contribute to the development of obesity and related metabolic disorders in progeny. Sirtuin (SIRT)1, an essential regulator of metabolism and stress responses, has recently emerged as an important modifying factor of developmental programming. In this study, to elucidate the effects of parental SIRT1 overexpression on offspring mechanism, four experimental groups were included: (1) Chow-fed wild-type (WT)-dam × Chow-fed WT-sire; (2) High-fat diet (HFD)-fed WT-dam × Chow-fed WT-sire; (3) HFD-fed hemizygous SIRT1-transgenic (Tg)-dam × Chow-fed WT-sire; and (4) HFD-fed WT dam × Chow-fed Tg-sire. Our results indicate that Tg breeders had lower body weight and fat mass compared to WT counterparts and gave birth to WT offspring with reductions in body weight, adiposity and hyperlipidaemia compared to those born of WT parents. Maternal SIRT1 overexpression also reversed glucose intolerance, and normalised abnormal fat morphology and the expression of dysregulated lipid metabolism markers, including SIRT1. Despite having persistent hepatic steatosis, offspring born to Tg parents showed an improved balance of hepatic glucose/lipid metabolic markers, as well as reduced levels of inflammatory markers and TGF-ß/Smad3 fibrotic signalling. Collectively, the data suggest that parental SIRT1 overexpression can ameliorate adverse metabolic programming effects by maternal obesity.

Defective insulin receptor signaling in patients with gestational diabetes is related to dysregulated miR-140 which can be improved by naringenin.

Gestational diabetes (GDM) affects about 20 % of pregnancies globally. Defective insulin receptor (IR) signaling has been found in the placenta from patients with GDM, but the underly mechanism is still unclear. In the present study, the mRNA and protein levels of IR-α, insulin receptor substrate 1(IRS-1) and inulin like growth factor 1 receptor (IGF1R) were detected in the placenta tissue samples from 33 GDM patients and 20 healthy controls. Reduced IR-α protein level was observed in both obese and non-obese GDM patients, and decreased IGF1R protein level was found in obese GDM patients. However, the IR-α and IGF1R mRNAs level was not significantly altered in GDM patients. Subsequently, the expression of 10 miRNAs that have the potential targeting IR-α and IGF1R was examined by qRT-PCR in the placenta, and miR-140-3p was found overexpressed. Through dual-luciferase assay and immunoblotting, miR-140-3p was confirmed to suppress IR-α and IGF1R expression via targeting the 3'UTRs. As a treatment candidate, naringenin downregulated miR-140-3p level in trophoblasts and endothelial cells. Meanwhile, IR-α and IGF1R expression was upregulated by naringenin, and the glucose uptake was increased in naringenin treated trophoblasts and endothelial cells. Finally, naringenin upregulated cell viability, migration capacity of HTR-8/SVneo and HUVEC cells, and increased HUVEC cells angiogenesis in high glucose condition. In conclusion, miR-140-3p overexpression contributes to the defective placental IR signaling in patients with GDM. Naringenin treatment protects trophoblasts and endothelial cells from the harmful high glucose environment which have the potential for GDM treatment.

Vitamin B12 deficiency and altered one-carbon metabolites in early pregnancy is associated with maternal obesity and dyslipidaemia.

Vitamin B12 (B12) is a micronutrient essential for one-carbon (1C) metabolism. B12 deficiency disturbs the 1C cycle and alters DNA methylation which is vital for most metabolic processes. Studies show that B12 deficiency may be associated with obesity, insulin resistance and gestational diabetes; and with obesity in child-bearing women. We therefore hypothesised that the associations between B12 deficiency, BMI and the metabolic risk could be mediated through altered 1C metabolites in early pregnancy. We explored these associations in two different early pregnancy cohorts in the UK (cohort 1; n = 244 and cohort 2; n = 60) with anthropometric data at 10-12 weeks and plasma/serum sampling at 16-18 weeks. B12, folate, total homocysteine (tHcy), methionine, MMA, metabolites of 1C metabolism (SAM, SAH) and anthropometry were measured. B12 deficiency (< 150 pmol/l) in early pregnancy was 23% in cohort 1 and 18% in cohort 2. Regression analysis after adjusting for likely confounders showed that B12 was independently and negatively associated with BMI (Cohort 1: ß = - 0.260, 95% CI (- 0.440, - 0.079), p = 0.005, Cohort 2: (ß = - 0.220, 95% CI (- 0.424, - 0.016), p = 0.036) and positively with HDL cholesterol (HDL-C) (ß = 0.442, 95% CI (0.011,0.873), p = 0.045). We found that methionine (ß = - 0.656, 95% CI (- 0.900, - 0.412), p < 0.0001) and SAH (ß = 0.371, 95% CI (0.071, 0.672), p = 0.017) were independently associated with triglycerides. Low B12 status and alteration in metabolites in 1C metabolism are common in UK women in early pregnancy and are independently associated with maternal obesity and dyslipidaemia. Therefore, we suggest B12 monitoring in women during peri-conceptional period and future studies on the pathophysiological relationship between changes in 1C metabolites and its association with maternal and fetal outcomes on larger cohorts. This in turn may offer potential to reduce the metabolic risk in pregnant women and their offspring.

Maternal obesity increases offspring's mammary cancer recurrence and impairs tumor immune response.

Over 50% of women at a childbearing age in the United States are overweight or obese, and this can adversely affect their offspring. We studied if maternal obesity-inducing high fat diet (HFD) not only increases offspring's mammary cancer risk but also impairs response to antiestrogen tamoxifen. Female rat offspring of HFD and control diet-fed dams, in which estrogen receptor-positive (ER+) mammary tumors were induced with the carcinogen 7,12-dimethylbenz[a]anthracene (DMBA), exhibited similar initial responses to antiestrogen tamoxifen. However, after tamoxifen therapy was completed, almost all (91%) tumors recurred in HFD offspring, compared with only 29% in control offspring. The increase in local mammary tumor recurrence in HFD offspring was linked to an increase in the markers of immunosuppression (Il17f, Tgfß1, VEGFR2) in the tumor microenvironment (TME). Protein and mRNA levels of the major histocompatibility complex II (MHC-II), but not MHC-I, were reduced in the recurring DMBA tumors of HFD offspring. Further, infiltration of CD8+ effector T cells and granzyme B+ (GZMB+) cells were lower in their recurring tumors. To determine if maternal HFD can pre-program similar changes in the TME of allografted E0771 mammary tumors in offspring of syngeneic mice, flow cytometry analysis was performed. E0771 mammary tumor growth was significantly accelerated in the HFD offspring, and a reduction in the numbers of GZMB and non-significant reduction of interferon γ (IFNγ) secreting CD8+ T cells in the TME was seen. Thus, consumption of a HFD during pregnancy increases susceptibility of the female rat and mouse offspring to tumor immune suppression and mammary tumor growth and recurrence.

The Burden of Placental Histopathology in Stillbirths Associated With Maternal Obesity.

OBJECTIVES: Obesity is an increasing health problem that has become a common medical disorder among women of childbearing age, representing worldwide a risk factor for stillbirth. The aim of the study is to evaluate the association between placental histopathologic findings and obesity in stillbirth. METHODS: Placentas were analyzed according to the Amsterdam consensus statement. Histologic findings in stillbirth from obese and lean mothers were analyzed and compared with those observed in liveborn controls. RESULTS: Stillbirth in obese mothers displayed placental pathology in all gestational ages, mostly at term of pregnancy. The most observed placental lesions were those consistent with maternal vascular malperfusion of the placental bed. Decidual arteriopathy and placental infarcts appeared specifically associated with maternal obesity. Moreover, obese women with stillbirth showed the highest cumulative number of placental lesions. CONCLUSIONS: Considering the significant association between stillbirth, maternal obesity, and placental histopathologic findings, health care providers should be aware about the importance of placental examination in obese women, especially in stillborn cases. The high prevalence of lesions consistent with vascular malperfusion of the placental bed suggests that stillbirth prevention strategies in obese women should rely on the development of tools to study and improve decidual artery functioning early in pregnancy.

Maternal high-fat diet induces long-term obesity with sex-dependent metabolic programming of adipocyte differentiation, hypertrophy and dysfunction in the offspring.

Maternal obesity determines obesity and metabolic diseases in the offspring. The white adipose tissue (WAT) orchestrates metabolic pathways, and its dysfunction contributes to metabolic disorders in a sex-dependent manner. Here, we tested if sex differences influence the molecular mechanisms of metabolic programming of WAT in offspring of obese dams. To this end, maternal obesity was induced with high-fat diet (HFD) and the offspring were studied at an early phase [postnatal day 21 (P21)], a late phase (P70) and finally P120. In the early phase we found a sex-independent increase in WAT in offspring of obese dams using magnetic resonance imaging (MRI), which was more pronounced in females than males. While the adipocyte size increased in both sexes, the distribution of WAT differed in males and females. As mechanistic hints, we identified an inflammatory response in females and a senescence-associated reduction in the preadipocyte factor DLK in males. In the late phase, the obese body composition persisted in both sexes, with a partial reversal in females. Moreover, female offspring recovered completely from both the adipocyte hypertrophy and the inflammatory response. These findings were linked to a dysregulation of lipolytic, adipogenic and stemness-related markers as well as AMPKα and Akt signaling. Finally, the sex-dependent metabolic programming persisted with sex-specific differences in adipocyte size until P120. In conclusion, we do not only provide new insights into the molecular mechanisms of sex-dependent metabolic programming of WAT dysfunction, but also highlight the sex-dependent development of low- and high-grade pathogenic obesity.

Maternal Overweight Downregulates MME (Neprilysin) in Feto-Placental Endothelial Cells and in Cord Blood.

Maternal overweight in pregnancy alters the metabolic environment and generates chronic low-grade inflammation. This affects fetal development and programs the offspring's health for developing cardiovascular and metabolic disease later in life. MME (membrane-metalloendopeptidase, neprilysin) cleaves various peptides regulating vascular tone. Endothelial cells express membrane-bound and soluble MME. In adults, the metabolic environment of overweight and obesity upregulates endothelial and circulating MME. We here hypothesized that maternal overweight increases MME in the feto-placental endothelium. We used primary feto-placental endothelial cells (fpEC) isolated from placentas after normal vs. overweight pregnancies and determined MME mRNA, protein, and release. Additionally, soluble cord blood MME was analyzed. The effect of oxygen and tumor necrosis factor α (TNFα) on MME protein in fpEC was investigated in vitro. Maternal overweight reduced MME mRNA (-39.9%, p < 0.05), protein (-42.5%, p = 0.02), and MME release from fpEC (-64.7%, p = 0.02). Both cellular and released MME protein negatively correlated with maternal pre-pregnancy BMI. Similarly, cord blood MME was negatively associated with pre-pregnancy BMI (r = -0.42, p = 0.02). However, hypoxia and TNFα, potential negative regulators of MME expression, did not affect MME protein. Reduction of MME protein in fpEC and in cord blood may alter the balance of vasoactive peptides. Our study highlights the fetal susceptibility to maternal metabolism and inflammatory state.

Maternal regulation of SATB2 in osteo-progeniters impairs skeletal development in offspring.

Nutritional status during intrauterine and/or early postnatal life has substantial influence on adult offspring health. Along these lines, there is a growing body of evidence illustrating that high fat diet (HFD)-induced maternal obesity can regulate fetal bone development. Thus, we investigated the effects of maternal obesity on both fetal skeletal development and mechanisms linking maternal obesity to osteoblast differentiation in offspring. Embryonic osteogenic calvarial cells (EOCCs) were isolated from fetuses at gestational day 18.5 (E18.5) of HFD-induced obese rat dams. We observed impaired differentiation of EOCCs to mature osteoblasts from HFD obese dams. ChIP-seq-based genome-wide localization of the repressive histone mark H3K27me3 (mediated via the polycomb histone methyltransferase, enhancer of zeste homologue 2 [Ezh2]) showed that this phenotype was associated with increased enrichment of H3K27me3 on the gene of SATB2, a critical transcription factor required for osteoblast differentiation. Knockdown of Ezh2 in EOCCs and ST2 cells increased SATB2 expression; while Ezh2 overexpression in EOCCs and ST2 cells decreased SATB2 expression. These data were consistent with experimental results showing strong association between H3K27me3, Ezh2, and SATB2 in cells from rats and humans. We have further presented that SATB2 mRNA and protein expression were increased in bones, and increased trabecular bone mass from pre-osteoblast specific Ezh2 deletion (Ezh2flox/flox Osx-Cre+ cko) mice compared with those from control Cre+ mice. These findings indicate that maternal HFD-induced obesity may be associated with decreasing fetal pre-osteoblastic cell differentiation, under epigenetic control of SATB2 expression via Ezh2-dependent mechanisms.

Evidence-based recommendations for energy intake in pregnant women with obesity.

BACKGROUND: In women with obesity, excess gestational weight gain (≥270 g/week) occurs in two out of three pregnancies and contributes to metabolic impairments in both mother and baby. To improve obstetrical care, objectively assessed information on energy balance is urgently needed. The objective of this study was to characterize determinants of gestational weight gain in women with obesity. METHODS: This was a prospective, observational study of pregnant women with obesity. The primary outcome was energy intake calculated by the energy intake-balance method. Energy expenditure was measured by doubly-labeled water and whole-room indirect calorimetry and body composition as 3-compartment model by air displacement plethysmography and isotope dilution in early (13-16 weeks) and late pregnancy (35-37 weeks). RESULTS: In pregnant women with obesity (n=54), recommended weight gain (n=8, 15%) during the second and third trimesters was achieved when energy intake was 125±52 kcal/d less than energy expenditure. In contrast, women with excess weight gain (67%) consumed 186±29 kcal/d more than they expended (P<0.001). Energy balance affected maternal adiposity (recommended: -2.5±0.8 kg fat mass, excess: +2.2±0.5, inadequate: -4.5±0.5, P<0.001), but not fetal growth. Weight gain was not related to demographics, activity, metabolic biomarkers, or diet quality. We estimated that energy intake requirements for recommended weight gain during the second and third trimesters were not increased as compared to energy requirements early in pregnancy (34±53 kcal/d, P=0.83). CONCLUSIONS: We here provide the first evidence-based recommendations for energy intake in pregnant women with obesity. Contrary to current recommendations, energy intake should not exceed energy expenditure. FUNDING: This study was funded by the National Institutes of Health (R01DK099175; Redman, U54GM104940 and P30DK072476; Core support). TRIAL REGISTRATION: clinicaltrials.gov: NCT01954342.