New development of the yolk sac theory in diabetic embryopathy: molecular mechanism and link to structural birth defects

Amniotic fluid-derived stem cells: potential factories of natural and mimetic strategies for congenital malformations

Background

Mesenchymal stem cells (MSCs) from gestational tissues represent promising strategies for in utero treatment of congenital malformations, but plasticity and required high-risk surgical procedures limit their use. Here we propose natural exosomes (EXOs) isolated from amniotic fluid-MSCs (AF-MSCs), and their mimetic counterparts (MIMs), as valid, stable, and minimally invasive therapeutic alternatives.

Methods

MIMs were generated from AF-MSCs by combining sequential filtration steps through filter membranes with different porosity and size exclusion chromatography columns. Physiochemical and molecular characterization was performed to compare them to EXOs released from the same number of cells. The possibility to exploit both formulations as mRNA-therapeutics was explored by evaluating cell uptake (using two different cell types, fibroblasts, and macrophages) and mRNA functionality overtime in an in vitro experimental setting as well as in an ex vivo, whole embryo culture using pregnant C57BL6 dams.

Results

Molecular and physiochemical characterization showed no differences between EXOs and MIMs, with MIMs determining a 3-fold greater yield. MIMs delivered a more intense and prolonged expression of mRNA encoding for green fluorescent protein (GFP) in macrophages and fibroblasts. An ex-vivo whole embryo culture demonstrated that MIMs mainly accumulate at the level of the yolk sac, while EXOs reach the embryo.

Conclusions

The present data confirms the potential application of EXOs for the prenatal repair of neural tube defects and proposes MIMs as prospective vehicles to prevent congenital malformations caused by in utero exposure to drugs.

MicroRNA-322 overexpression reduces neural tube defects in diabetic pregnancies

BACKGROUND

Hyperglycemia from pregestational diabetes mellitus induces neural tube defects in the developing fetus. Folate supplementation is the only effective way to prevent neural tube defects; however, some cases of neural tube defects are resistant to folate. Excess folate has been linked to higher maternal cancer risk and infant allergy. Therefore, additional interventions are needed. Understanding the mechanisms underlying maternal diabetes mellitus-induced neural tube defects can identify potential targets for preventing such defects. Despite not yet being in clinical use, growing evidence suggests that microRNAs are important intermediates in embryonic development and can serve as both biomarkers and drug targets for disease intervention. Our previous studies showed that maternal diabetes mellitus in vivo activates the inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) in the developing embryo and that a high glucose condition in vitro reduces microRNA-322 (miR-322) levels. IRE1α is an RNA endonuclease; however, it is unknown whether IRE1α targets and degrades miR-322 specifically or whether miR-322 degradation leads to neural tube defects via apoptosis. We hypothesize that IRE1α can inhibit miR-322 in maternal diabetes mellitus-induced neural tube defects and that restoring miR-322 expression in developing neuroepithelium ameliorates neural tube defects.

OBJECTIVE

This study aimed to identify potential targets for preventing maternal diabetes mellitus-induced neural tube defects and to investigate the roles and relationship of a microRNA and an RNA endonuclease in mouse embryos exposed to maternal diabetes mellitus.

STUDY DESIGN

To determine whether miR-322 reduction is necessary for neural tube defect formation in pregnancies complicated by diabetes mellitus, male mice carrying a transgene expressing miR-322 were mated with nondiabetic or diabetic wide-type female mice to generate embryos with or without miR-322 overexpression. At embryonic day 8.5 when the neural tube is not yet closed, embryos were harvested for the assessment of 3 miR-322 transcripts (primary, precursor, and mature miR-322), tumor necrosis factor receptor-associated factor 3 (TRAF3), and neuroepithelium cell survival. Neural tube defect incidences were determined in embryonic day 10.5 embryos when the neural tube should be closed if there is no neural tube defect formation. To identify which miR-322 transcript is affected by maternal diabetes mellitus and high glucose conditions, 3 miR-322 transcripts were assessed in embryos from dams with or without diabetes mellitus and in C17.2 mouse neural stem cells treated with different concentrations of glucose and at different time points. To determine whether the endonuclease IRE1α targets miR-322, small interfering RNA knockdown of IRE1α or overexpression of inositol-requiring transmembrane kinase/endoribonuclease 1α by DNA plasmid transfection was used to determine the effect of IRE1α deficiency or overexpression on miR-322 expression. RNA immunoprecipitation was performed to reveal the direct targets of inositol-requiring transmembrane kinase/endoribonuclease 1α.

RESULTS

Maternal diabetes mellitus suppressed miR-322 expression in the developing neuroepithelium. Restoring miR-322 expression in the neuroepithelium blocked maternal diabetes mellitus-induced caspase-3 and caspase-8 cleavage and cell apoptosis, leading to a neural tube defect reduction. Reversal of maternal diabetes mellitus-inhibited miR-322 via transgenic overexpression prevented TRAF3 up-regulation in embryos exposed to maternal diabetes mellitus. Activated IRE1α acted as an endonuclease and degraded precursor miR-322, resulting in mature miR-322 reduction.

CONCLUSION

This study supports the crucial role of the IRE1α-microRNA-TRAF3 circuit in the induction of neuroepithelial cell apoptosis and neural tube defect formation in pregnancies complicated by diabetes mellitus and identifies IRE1α and miR-322 as potential targets for preventing maternal diabetes mellitus-induced neural tube defects.

High amniotic fluid fractalkine and MIP-1β levels are associated with intrauterine growth restriction: a prospective cohort study

Background/aim

Proinflammatory chemokines have been shown to play crucial roles in implantation, spiral artery invasion, and the fetomaternal immunological response. In this context, we investigated the levels of fractalkine (CX3CL1) and chemokine CC motif ligand 4 (CCL4 or MIP-1β) in maternal serum and amniotic fluids in pregnant women with intrauterine growth restriction (IUGR).

Materials and methods

This prospective cohort study was carried out at Fırat University Obstetrics Clinic between January 1, 2022 and July 1, 2022. Group (G) 1: The control group consisted of 40 pregnant women who underwent elective cesarean section (CS) at 38-40 weeks of gestation. G2: A total of 40 pregnant women with IUGR at 28-37 weeks of gestation were included in the study group. Levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interferon-gamma (IFN-γ), hypoxia-inducible factor-1 alpha (HIF-1α), macrophage inflammatory protein-1 beta (MIP-1β), and fractalkine were measured in maternal serum and amniotic fluid samples obtained during CS.

Results

When maternal age was compared, no statistically significant difference was observed between G1 and G2 (p = 0.374). The number of gravidity was found to be statistically higher in G1 compared to G2 (p = 0.003). The mean gestational week was statistically higher in G1 (p < 0.001). Maternal serum MIP-1β (p = 0.03) and IFN-γ (p = 0.006) levels were higher in G1. The birth weight of the baby (p < 0.001) and umbilical cord blood gas pH value (p < 0.001) at birth were higher in G1. HIF-1α (p < 0.001), fractalkine (p < 0.001), MIP-1β (p < 0.001), TNF-α (p = 0.007), IL-1β (p < 0.001), and IFN-γ levels (p = 0.007) in amniotic fluid were higher in G2.

Conclusion

Elevated levels of proinflammatory factors, including fractalkine and MIP-1β, along with inflammatory factors such as TNF-α, IL-1β, and IFN-γ, as well as increased HIF-1α levels in amniotic fluid, are associated with intrauterine growth restriction (IUGR) attributed to a hypoxic amniotic environment.

Phenotypically Discordant Anomalies in Conjoined Twins: Quirks of Nature Governed by Molecular Pathways?

A multitude of additional anomalies can be observed in virtually all types of symmetrical conjoined twins. These concomitant defects can be divided into different dysmorphological patterns. Some of these patterns reveal their etiological origin through their topographical location. The so-called shared anomalies are traceable to embryological adjustments and directly linked to the conjoined-twinning mechanism itself, inherently located within the boundaries of the coalescence area. In contrast, discordant patterns are anomalies present in only one of the twin members, intrinsically distant from the area of union. These dysmorphological entities are much more difficult to place in a developmental perspective, as it is presumed that conjoined twins share identical intra-uterine environments and intra-embryonic molecular and genetic footprints. However, their existence testifies that certain developmental fields and their respective developmental pathways take different routes in members of conjoined twins. This observation remains a poorly understood phenomenon. This article describes 69 cases of external discordant patterns within different types of otherwise symmetrical mono-umbilical conjoined twins and places them in a developmental perspective and a molecular framework. Gaining insights into the phenotypes and underlying (biochemical) mechanisms could potentially pave the way and generate novel etiological visions in the formation of conjoined twins itself.

Yolk sac development, function and role in rodent pregnancy

During the early phases of embryonic development, the yolk sac serves as an initial placenta in many animal species. While in some, this role subsides around the end of active organogenesis, it continues to have important functions in rodents, alongside the chorio-allantoic placenta. The yolk sac is the initial site of hematopoiesis in many animal species including primates. Cells of epiblastic origin form blood islands that are the forerunners of hematopoietic cells and of the primitive endothelial cells that form the vitelline circulation. The yolk sac is also a major route of embryonic and fetal nutrition apparently as long as it functions. In mammals and especially rodents, macro and micronutrients are absorbed by active pinocytosis into the visceral yolk sac, degraded and the degradation products (i.e., amino acids) are then transferred to the embryo. Interference with the yolk sac function may directly reflect on embryonic growth and development, inducing congenital malformations or in extreme damage, causing embryonic and fetal death. In rodents, many agents were found to damage the yolk sac (i.e., anti-yolk sac antibodies or toxic substances interfering with yolk sac pinocytosis) subsequently affecting the embryo/fetus. Often, the damage to the yolk sac is transient while embryonic damage persists. In humans, decreased yolk sac diameter was associated with diabetic pregnancies and increased diameter was associated with pregnancy loss. In addition, culture of rat yolk sacs in serum obtained from pregnant diabetic women or from women with autoimmune diseases induced severe damage to the visceral yolk sac epithelium and embryonic malformations. It can be concluded that as a result of the crucial role of the yolk sac in the well-being of the early embryo, any damage to its normal function may severely and irreversibly affect further development of the embryo/fetus.

Functional cargos of exosomes derived from Flk-1+ vascular progenitors enable neurulation and ameliorate embryonic anomalies in diabetic pregnancy

Various types of progenitors initiate individual organ formation and their crosstalk orchestrates morphogenesis for the entire embryo. Here we show that progenitor exosomal communication across embryonic organs occurs in normal development and is altered in embryos of diabetic pregnancy. Endoderm fibroblast growth factor 2 (FGF2) stimulates mesoderm Flk-1+ vascular progenitors to produce exosomes containing the anti-stress protein Survivin. These exosomes act on neural stem cells of the neuroepithelium to facilitate neurulation by inhibiting cellular stress and apoptosis. Maternal diabetes causes Flk-1+ progenitor dysfunction by suppressing FGF2 through DNA hypermethylation. Restoring endoderm FGF2 prevents diabetes-induced survivin reduction in Flk-1+ progenitor exosomes. Transgenic Survivin expression in Flk-1+ progenitors or in utero delivery of survivin-enriched exosomes restores cellular homeostasis and prevents diabetes-induced neural tube defects (NTDs), whereas inhibiting exosome production induces NTDs. Thus, functional inter-organ communication via Flk-1 exosomes is vital for neurulation and its disruption leads to embryonic anomalies.

Novel risk factors for craniofacial microsomia and assessment of their utility in clinic diagnosis

Craniofacial microsomia (CFM, OMIM%164 210) is one of the most common congenital facial abnormalities worldwide, but it's genetic risk factors and environmental threats are poorly investigated, as well as their interaction, making the diagnosis and prenatal screening of CFM impossible. We perform a comprehensive association study on the largest CFM cohort of 6074 samples. We identify 15 significant (P < 5 × 10-8) associated genomic loci (including eight previously reported) and decipher 107 candidates based on multi-omics data. Gene Ontology term enrichment found that these candidates are mainly enriched in neural crest cell (NCC) development and hypoxic environment. Single-cell RNA-seq data of mouse embryo demonstrate that nine of them show dramatic expression change during early cranial NCC development whose dysplasia is involved in pathogeny of CFM. Furthermore, we construct a well-performed CFM risk-predicting model based on polygenic risk score (PRS) method and estimate seven environmental risk factors that interacting with PRS. Single-nucleotide polymorphism-based PRS is significantly associated with CFM [P = 7.22 × 10-58, odds ratio = 3.15, 95% confidence interval (CI) 2.74-3.63], and the top fifth percentile has a 6.8-fold CFM risk comparing with the 10th percentile. Father's smoking increases CFM risk as evidenced by interaction parameter of -0.324 (95% CI -0.578 to -0.070, P = 0.011) with PRS. In conclusion, the newly identified risk loci will significantly improve our understandings of genetics contribution to CFM. The risk prediction model is promising for CFM prediction, and father's smoking is a key environmental risk factor for CFM through interacting with genetic factors.

Deficiency of the oxidative stress-responsive kinase p70S6K1 restores autophagy and ameliorates neural tube defects in diabetic embryopathy

BACKGROUND

Autophagy is highly active in neuroepithelial cells of the developing neuroepithelium, and impairment of autophagy leads to neural tube defects. In this study, we have found that maternal diabetes suppresses autophagy that leads to neural tube defects and consequent cellular imbalance in the endoplasmic reticulum where critical events occur, leading to the induction of diabetic embryopathy. Because the mammalian target of rapamycin pathway suppresses autophagy, we hypothesized that 70 kDa ribosomal protein S6 kinase 1 (p70S6K1), a major downstream effector of mammalian target of rapamycin, mediates the inhibitory effect of maternal diabetes on autophagy in the developing neuroepithelium.

OBJECTIVE

We investigated whether p70S6K1 mediates the inhibitory effect of maternal diabetes on autophagy during neurulation. We also examined whether p70S6K1 deficiency restores autophagy and therefore relieves endoplasmic reticulum stress and inhibits maternal diabetes-induced apoptosis, which leads to reduction in neural tube defect incidence in diabetic embryopathy.

STUDY DESIGN

Female p70S6K1 heterogeneous knockout (p70S6K1+/-) mice were bred with male p70S6K1 heterogeneous knockout (p70S6K1+/-) mice to generate wild-type (WT), p70S6K1+/- and p70S6K1 knockout (p70S6K1-/-) embryos. Embryos at embryonic day 8.5 were harvested for the assessment of indices of autophagy, endoplasmic reticulum stress, and apoptosis. Neural tube defect incidence in embryos was determined at embryonic day 10.5. For in vitro studies, small interfering RNA knockdown of p70S6K1 in C17.2 mouse neural stem cells was used to determine the effect of p70S6K1 deficiency on autophagy impairment and endoplasmic reticulum stress under high glucose conditions.

RESULTS

Knockout of the Rps6kb1 gene, which encodes for p70S6K1, ameliorated maternal diabetes-induced NTDs and restored autophagosome formation in neuroepithelial cells suppressed by maternal diabetes. Maternal diabetes-suppressed conversion of LC3-I (microtubule-associated protein 1A/1B-light chain 3) to LC3-II, an index of autophagic activity, in neurulation stage embryos was abrogated in the absence of p70S6K1. p70S6K1 knockdown in neural stem cells also restored autophagosome formation and the conversion of LC3-I to LC3-II. The activation of the major unfolded protein response, indicated by phosphorylation of inositol-requiring enzyme 1 alpha, and protein kinase R-like endoplasmic reticulum kinase, and eukaryotic translation initiation factor 2α, and the increase of the endoplasmic reticulum stress marker, C/EBP homologous protein, were induced by maternal diabetes in vivo and high glucose in vitro. Unfolded protein response and endoplasmic reticulum stress induced by maternal diabetes or high glucose were reduced by Rps6kb1 deletion or p70S6K1 knockdown, respectively. Rps6kb1 knockout blocked maternal diabetes-induced caspase cleavage and neuroepithelial cell apoptosis. The superoxide dismutase mimetic Tempol abolished high glucose-induced p70S6K1 activation.

CONCLUSION

The study revealed the critical involvement of p70S6K1 in the pathogenesis of diabetic embryopathy.

Restoring BMP4 expression in vascular endothelial progenitors ameliorates maternal diabetes-induced apoptosis and neural tube defects

During mouse embryonic development, vasculogenesis initially occurs in the yolk sac, preceding neurulation. Our previous studies have demonstrated that maternal diabetes induces embryonic vasculopathy at early embryonic developmental stage by suppressing the expression of vascular growth factors including BMP4 (bone morphogenetic protein 4). This study aimed to determine whether restoring diabetes-inhibited BMP4 expression in Flk-1+ progenitors effectively prevented maternal diabetes-induced embryonic vasculopathy and NTDs. Transgenic (Tg) BMP4 expression in the vascular endothelial growth factor receptor 2 (Flk-1)-positive (Flk-1+) progenitors was achieved by crossing a Floxed BMP4 Tg mouse line with the Flk-1-Cre mouse line. Non-BMP4 Tg and BMP4 Tg embryos were harvested at E8.5 to assess the expression of BMP4, markers of endoplasmic reticulum stress, and expression of the Id genes, direct targets of BMP4; and the presence of cleaved caspase 3 and 8, apoptosis, and Smad signaling. BMP4 Tg overexpression neutralized its down-regulation by maternal diabetes in E8.5 embryos. Maternal diabetes-induced Flk-1+ progenitor apoptosis, impairment of blood island formation, and reduction of Flk-1+ progenitor number and blood vessel density, which were reversed by BMP4 Tg expression. BMP4 Tg expression in Flk-1+ progenitors blocked maternal diabetes-induced vasculopathy in early stage embryos (E7.5-E8.5) and consequently led to amelioration of maternal diabetes-induced neural tube defects (NTDs) at E10.5. BMP4 Tg expression inhibited maternal diabetes-induced endoplasmic reticulum stress and caspase cascade activation in the developing neuroepithelium, and reduced neuroepithelial cell apoptosis. BMP4 Tg expression re-activated Smad1/5/8 phosphorylation and reversed maternal diabetes-suppressed Smad4 expression. BMP4 Tg expression restored Id1 and Smad6 expression inhibited by maternal diabetes. In vitro, recombinant BMP4 protein blocked high glucose-induced Flk-1+ progenitor apoptosis and NTDs. These data demonstrate that BMP4 down-regulation in Flk-1+ progenitors are responsible for diabetes-induced yolk sac vasculopathy, and that restoring BMP4 expression prevents vasculopathy and rescues neuroepithelial cells from cellular organelle stress, leading to NTD reduction.

Identification of novel candidate risk genes for myelomeningocele within the glucose homeostasis/oxidative stress and folate/one-carbon metabolism networks

Background

Neural tube defects (NTDs) are the second most common complex birth defect, yet, our understanding of the genetic contribution to their development remains incomplete. Two environmental factors associated with NTDs are Folate and One Carbon Metabolism (FOCM) and Glucose Homeostasis and Oxidative Stress (GHOS). Utilizing next‐generation sequencing of a large patient cohort, we identify novel candidate genes in these two networks to provide insights into NTD mechanisms.

Methods

Exome sequencing (ES) was performed in 511 patients, born with myelomeningocele, divided between European American and Mexican American ethnicities. Healthy control data from the Genome Aggregation database were ethnically matched and used as controls. Rare, high fidelity, nonsynonymous predicted damaging missense, nonsense, or canonical splice site variants in independently generated candidate gene lists for FOCM and GHOS were identified. We used a gene‐based collapsing approach to quantify mutational burden in case and controls, with the control cohort estimated using cumulative allele frequencies assuming Hardy–Weinberg equilibrium.

Results

We identified 45 of 837 genes in the FOCM network and 22 of 568 genes in the GHOS network as possible NTD risk genes with p < 0.05. No nominally significant risk genes were shared between ethnicities. Using a novel approach to mutational burden we identify 55 novel NTD risk associations.

Conclusions

We provide a means of utilizing large publicly available sequencing datasets as controls for sequencing projects examining rare disease. This approach confirmed existing risk genes for myelomeningocele and identified possible novel risk genes. Lastly, it suggests possible distinct genetic etiologies for this malformation between different ethnicities.

Exposure-based assessment of chemical teratogenicity using morphogenetic aggregates of human embryonic stem cells

Pluripotent stem cells recapitulate many aspects of embryogenesis in vitro. Here, we established a novel culture system to differentiate human embryonic stem cell aggregates (HESCA), and evaluated its utility for teratogenicity assessment. Culture of HESCA with modulators of developmental signals induced morphogenetic and molecular changes associated with differentiation of the paraxial mesoderm and neuroectoderm. To examine impact of teratogenic exposures on HESCA differentiation, 18 compounds were tested, for which adequate information on in vivo plasma concentrations is available. HESCA treated with each compound were examined for gross morphology and transcript levels of 15 embryogenesis regulator genes. Significant alterations in the transcript levels were observed for 94% (15/16) of the teratogenic exposures within 5-fold margin, whereas no alteration was observed for 92% (11/12) of the non-teratogenic exposures. Our study demonstrates that transcriptional changes in HESCA serve as predictive indicator of teratogenicity in a manner comparable to in vivo exposure levels.

High Glucose Inhibits Neural Stem Cell Differentiation Through Oxidative Stress and Endoplasmic Reticulum Stress

Maternal diabetes induces neural tube defects by suppressing neurogenesis in the developing neuroepithelium. Our recent study further revealed that high glucose inhibited embryonic stem cell differentiation into neural lineage cells. However, the mechanism whereby high glucose suppresses neural differentiation is unclear. To investigate whether high glucose-induced oxidative stress and endoplasmic reticulum (ER) stress lead to the inhibition of neural differentiation, the effect of high glucose on neural stem cell (the C17.2 cell line) differentiation was examined. Neural stem cells were cultured in normal glucose (5 mM) or high glucose (25 mM) differentiation medium for 3, 5, and 7 days. High glucose suppressed neural stem cell differentiation by significantly decreasing the expression of the neuron marker Tuj1 and the glial cell marker GFAP and the numbers of Tuj1⁺ and GFAP⁺ cells. The antioxidant enzyme superoxide dismutase mimetic Tempol reversed high glucose-decreased Tuj1 and GFAP expression and restored the numbers of neurons and glial cells differentiated from neural stem cells. Hydrogen peroxide treatment imitated the inhibitory effect of high glucose on neural stem cell differentiation. Both high glucose and hydrogen peroxide triggered ER stress, whereas Tempol blocked high glucose-induced ER stress. The ER stress inhibitor, 4-phenylbutyrate, abolished the inhibition of high glucose or hydrogen peroxide on neural stem cell differentiation. Thus, oxidative stress and its resultant ER stress mediate the inhibitory effect of high glucose on neural stem cell differentiation.

The increased activity of a transcription factor inhibits autophagy in diabetic embryopathy

BACKGROUND

Maternal diabetes induces neural tube defects and stimulates the activity of the forkhead box O3 (Fox)O3a in the embryonic neuroepithelium. We previously demonstrated that deleting the FOXO3a gene ameliorates maternal diabetes-induced neural tube defects. Macroautophagy (hereafter referred to as "autophagy") is essential for neurulation. Rescuing autophagy suppressed by maternal diabetes in the developing neuroepithelium inhibits neural tube defect formation in diabetic pregnancy. This evidence suggests a possible link between FoxO3a and impaired autophagy in diabetic embryopathy.

OBJECTIVE

We aimed to determine whether maternal diabetes suppresses autophagy through FoxO3a, and if the transcriptional activity of FoxO3a is required for the induction of diabetic embryopathy.

STUDY DESIGN

We used a well-established type 1 diabetic embryopathy mouse model, in which diabetes was induced by streptozotocin, for our in vivo studies. To determine if FoxO3a mediates the inhibitory effect of maternal diabetes on autophagy in the developing neuroepithelium, we induced diabetic embryopathy in FOXO3a gene knockout mice and FoxO3a dominant negative transgenic mice. Embryos were harvested at embryonic day 8.5 to determine FoxO3a and autophagy activity and at embryonic day 10.5 for the presence of neural tube defects. We also examined the expression of autophagy-related genes. C17.2 neural stem cells were used for in vitro examination of the potential effects of FoxO3a on autophagy.

RESULTS

Deletion of the FOXO3a gene restored the autophagy markers, lipidation of microtubule-associated protein 1A/1B-light chain 3I to light chain 3II, in neurulation stage embryos. Maternal diabetes decreased light chain 3I-positive puncta number in the neuroepithelium, which was restored by deleting FoxO3a. Maternal diabetes also decreased the expression of positive regulators of autophagy (Unc-51 like autophagy activating kinase 1, Coiled-coil myosin-like BCL2-interacting protein, and autophagy-related gene 5) and the negative regulator of autophagy, p62. FOXO3a gene deletion abrogated the dysregulation of autophagy genes. In vitro data showed that the constitutively active form of FoxO3a mimicked high glucose in repressing autophagy. In cells cultured under high-glucose conditions, overexpression of the dominant negative FoxO3a mutant blocked autophagy impairment. Dominant negative FoxO3a overexpression in the developing neuroepithelium restored autophagy and significantly reduced maternal diabetes-induced apoptosis and neural tube defects.

CONCLUSION

Our study revealed that diabetes-induced FoxO3a activation inhibited autophagy in the embryonic neuroepithelium. We also observed that FoxO3a transcriptional activity mediated the teratogenic effect of maternal diabetes because dominant negative FoxO3a prevents maternal diabetes-induced autophagy impairment and neural tube defect formation. Our findings suggest that autophagy activators could be therapeutically effective in treating maternal diabetes-induced neural tube defects.

Offspring of mothers with hyperglycaemia in pregnancy: The short term and long-term impact. What is new?

The continuing rise in the global prevalence of diabetes and overweight or obesity has become a major burden for global health, as the pandemic is affecting both high and low-middle income countries (LMIC). At the same time, a similar pattern has been observed for all forms of hyperglycemia in pregnancy (HIP), diabetes during pregnancy and gestational diabetes. The offspring of mothers with HIP and/or overweight-obesity is receiving increasing attention as advances in early detection and treatment of HIP did not completely prevent macrosomia and its associated short-term perinatal disorders, whilst long term consequences are observed in the mother and in offspring as it reaches adulthood. This review discusses the current developments in the consequences of HIP in the offspring, with a particular focus on its long-term health at adulthood, and on intergenerational and transgenerational effects. HIP is emerging as one of the factors that can contribute, during the window of sensitivity to environmental cues constituted by the preconception, pregnancy, and early childhood, and as an amplifying factor linked to reproduction, to the current global epidemic of diabetes and non-communicable diseases (NCDs).

Etiology and Pathogenesis of Hemifacial Microsomia

Hemifacial microsomia (HFM) is a common congenital malformation of the craniofacial region. There are 3 possible pathogenic models of HFM—vascular abnormality and hemorrhage in the craniofacial region, damage to Meckel’s cartilage, and the abnormal development of cranial neural crest cells—and the most plausible hypothesis is the vascular abnormality and hemorrhage model. These 3 models are interrelated, and none of them is completely concordant with all the variable manifestations of HFM. External environmental factors (e.g., thalidomide, triazene, retinoic acid, and vasoactive medications), maternal intrinsic factors (e.g., maternal diabetes), and genetic factors (e.g., the recently reported mutations in OTX2, PLCD3, and MYT1) may lead to HFM through ≥1 of these pathogenic processes. Whole genome sequencing to identify additional pathogenic variants, biological functional studies to understand the exact molecular mechanisms, and additional animal model and clinical studies with large stratified samples to elucidate the pathogenesis of HFM will be necessary. Small-molecule drugs, as well as CRISPR/CAS9-based genetic interventions, for the prevention and treatment of HFM may also be a future research hotspot.

Endoplasmic Reticulum Stress-Induced CHOP Inhibits PGC-1α and Causes Mitochondrial Dysfunction in Diabetic Embryopathy

Endoplasmic reticulum (ER) stress has been implicated in the development of maternal diabetes-induced neural tube defects (NTDs). ER stress-induced C/EBP homologous protein (CHOP) plays an important role in the pro-apoptotic execution pathways. However, the molecular mechanism underlying ER stress- and CHOP-induced neuroepithelium cell apoptosis in diabetic embryopathy is still unclear. Deletion of the Chop gene significantly reduced maternal diabetes-induced NTDs. CHOP deficiency abrogated maternal diabetes-induced mitochondrial dysfunction and neuroepithelium cell apoptosis. Further analysis demonstrated that CHOP repressed the expression of peroxisome-proliferator-activated receptor-γ coactivator-1α (PGC-1α), an essential regulator for mitochondrial biogenesis and function. Both CHOP deficiency in vivo and knockdown in vitro restore high glucose-suppressed PGC-1α expression. In contrast, CHOP overexpression mimicked inhibition of PGC-1α by high glucose. In response to the ER stress inducer tunicamycin, PGC-1α expression was decreased, whereas the ER stress inhibitor 4-phenylbutyric acid blocked high glucose-suppressed PGC-1α expression. Moreover, maternal diabetes in vivo and high glucose in vitro promoted the interaction between CHOP and the PGC-1α transcriptional regulator CCAAT/enhancer binding protein-β (C/EBPβ), and reduced C/EBPβ binding to the PGC-1α promoter leading to markedly decrease in PGC-1α expression. Together, our findings support the hypothesis that maternal diabetes-induced ER stress increases CHOP expression which represses PGC-1α through suppressing the C/EBPβ transcriptional activity, subsequently induces mitochondrial dysfunction and ultimately results in NTDs.

Adverse effects of Hif1a mutation and maternal diabetes on the offspring heart

Background

Epidemiological studies show that maternal diabetes predisposes offspring to cardiovascular and metabolic disorders. However, the precise mechanisms for the underlying penetrance and disease predisposition remain poorly understood. We examined whether hypoxia-inducible factor 1 alpha, in combination with exposure to a diabetic intrauterine environment, influences the function and molecular structure of the adult offspring heart.

Methods and results

In a mouse model, we demonstrated that haploinsufficient (Hif1a^+/−) offspring from a diabetic pregnancy developed left ventricle dysfunction at 12 weeks of age, as manifested by decreased fractional shortening and structural remodeling of the myocardium. Transcriptional profiling by RNA-seq revealed significant transcriptome changes in the left ventricle of diabetes-exposed Hif1a^+/− offspring associated with development, metabolism, apoptosis, and blood vessel physiology. In contrast, both wild type and Hif1a^+/− offspring from diabetic pregnancies showed changes in immune system processes and inflammatory responses. Immunohistochemical analyses demonstrated that the combination of haploinsufficiency of Hif1a and exposure to maternal diabetes resulted in impaired macrophage infiltration, increased levels of advanced glycation end products, and changes in vascular homeostasis in the adult offspring heart.

Conclusions

Together our findings provide evidence that a global reduction in Hif1a gene dosage increases predisposition of the offspring exposed to maternal diabetes to cardiac dysfunction, and also underscore Hif1a as a critical factor in the fetal programming of adult cardiovascular disease.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0713-0) contains supplementary material, which is available to authorized users.

Oxidative stress-induced miR-27a targets the redox gene nuclear factor erythroid 2-related factor 2 in diabetic embryopathy

BACKGROUND

Maternal diabetes induces neural tube defects, and oxidative stress is a causal factor for maternal diabetes-induced neural tube defects. The redox gene nuclear factor erythroid 2-related factor 2 is the master regulator of the cellular antioxidant system.

OBJECTIVE

In this study, we aimed to determine whether maternal diabetes inhibits nuclear factor erythroid 2-related factor 2 expression and nuclear factor erythroid 2-related factor 2-controlled antioxidant genes through the redox-sensitive miR-27a.

STUDY DESIGN

We used a well-established type 1 diabetic embryopathy mouse model induced by streptozotocin for our in vivo studies. Embryos at embryonic day 8.5 were harvested for analysis of nuclear factor erythroid 2-related factor 2, nuclear factor erythroid 2-related factor 2-controlled antioxidant genes, and miR-27a expression. To determine if mitigating oxidative stress inhibits the increase of miR-27a and the decrease of nuclear factor erythroid 2-related factor 2 expression, we induced diabetic embryopathy in superoxide dismutase 2 (mitochondrial-associated antioxidant gene)-overexpressing mice. This model exhibits reduced mitochondria reactive oxygen species even in the presence of hyperglycemia. To investigate the causal relationship between miR-27a and nuclear factor erythroid 2-related factor 2 in vitro, we examined C17.2 neural stem cells under normal and high-glucose conditions.

RESULTS

We observed that the messenger RNA and protein levels of nuclear factor erythroid 2-related factor 2 were significantly decreased in embryos on embryonic day 8.5 from diabetic dams compared to those from nondiabetic dams. High-glucose also significantly decreased nuclear factor erythroid 2-related factor 2 expression in a dose- and time-dependent manner in cultured neural stem cells. Our data revealed that miR-27a was up-regulated in embryos on embryonic day 8.5 exposed to diabetes, and that high glucose increased miR-27a levels in a dose- and time-dependent manner in cultured neural stem cells. In addition, we found that a miR-27a inhibitor abrogated the inhibitory effect of high glucose on nuclear factor erythroid 2-related factor 2 expression, and a miR-27a mimic suppressed nuclear factor erythroid 2-related factor 2 expression in cultured neural stem cells. Furthermore, our data indicated that the nuclear factor erythroid 2-related factor 2-controlled antioxidant enzymes glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit, and glutathione S-transferase A1 were down-regulated by maternal diabetes in embryos on embryonic day 8.5 and high glucose in cultured neural stem cells. Inhibiting miR-27a restored expression of glutamate-cysteine ligase catalytic subunit, glutamate-cysteine ligase modifier subunit, and glutathione S-transferase A1. Overexpressing superoxide dismutase 2 reversed the maternal diabetes-induced increase of miR-27a and suppression of nuclear factor erythroid 2-related factor 2 and nuclear factor erythroid 2-related factor 2-controlled antioxidant enzymes.

CONCLUSION

Our study demonstrates that maternal diabetes-induced oxidative stress increases miR-27a, which, in turn, suppresses nuclear factor erythroid 2-related factor 2 and its responsive antioxidant enzymes, resulting in diabetic embryopathy.

Nutraceutical prospective: The synergetic mechanism of action of inositols and resveratrol on metabolic syndrome

It has been known that inositols function as insulin second messengers and mediate different insulin-dependent processes and are a valid natural, non-pharmaceutical alternative to contrast insulin-resistance as well as associated metabolic syndrome in women with Polycystic ovarian disease (PCOS). Several studies also have shown positive effects of resveratrol in reducing glucose and lipid concentrations in patients. Recently, clinical evidence has proven that an D-chiro-inositol/resveratrol combination has a potential role to play in maintaining metabolic and endocrine health, however no large clinical trials have demonstrated the medical effectiveness of the combination, and the combined mode of action remains poorly discussed. Herein, we address the hypothesis of a synergistic mechanism adopted by D-chiro-inositol and resveratrol in reducing insulin resistance and hyperlipidemia and thus showing a greater therapeutic potential compared to treatment with inositol’s alone.

The current status and future of cardiac stem/progenitor cell therapy for congenital heart defects from diabetic pregnancy

Pregestational maternal diabetes induces congenital heart defects (CHDs). Cardiac dysfunction after palliative surgical procedures contributes to the high mortality of CHD patients. Autologous or allogeneic stem cell therapies are effective for improving cardiac function in animal models and clinical trials. c-kit+ cardiac progenitor cells (CPCs), the most recognized CPCs, have the following basic properties of stem cells: self-renewal, multicellular clone formation, and differentiation into multiple cardiac lineages. However, there is ongoing debate regarding whether c-kit+ CPCs can give rise to sufficient cardiomyocytes. A new hypothesis to address the beneficial effect of c-kit+ CPCs is that these cells stimulate endogenous cardiac cells through a paracrine function in producing a robust secretome and exosomes. The values of other cardiac CPCs, including Sca1+ CPCs and cardiosphere-derived cells, are beginning to be revealed. These cells may be better choices than c-kit+ CPCs for generating cardiomyocytes. Adult mesenchymal stem cells are considered immune-incompetent and effective for improving cardiac function. Autologous CPC therapy may be limited by the observation that maternal diabetes adversely affects the biological function of embryonic stem cells and CPCs. Future studies should focus on determining the mechanistic action of these cells, identifying new CPC markers, selecting highly effective CPCs, and engineering cell-free products.

Pregestational type 2 diabetes mellitus induces cardiac hypertrophy in the murine embryo through cardiac remodeling and fibrosis

BACKGROUND

Cardiac hypertrophy is highly prevalent in patients with type 2 diabetes mellitus. Experimental evidence has implied that pregnant women with type 2 diabetes mellitus and their children are at an increased risk of cardiovascular diseases. Our previous mouse model study revealed that maternal type 2 diabetes mellitus induces structural heart defects in their offspring.

OBJECTIVE

This study aims to determine whether maternal type 2 diabetes mellitus induces embryonic heart hypertrophy in a murine model of diabetic embryopathy.

STUDY DESIGN

The type 2 diabetes mellitus embryopathy model was established by feeding 4-week-old female C57BL/6J mice with a high-fat diet for 15 weeks. Cardiac hypertrophy in embryos at embryonic day 17.5 was characterized by measuring heart size and thickness of the right and left ventricle walls and the interventricular septum, as well as the expression of β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, desmin, and adrenomedullin. Cardiac remodeling was determined by collagen synthesis and fibronectin synthesis. Fibrosis was evaluated by Masson staining and determining the expression of connective tissue growth factor, osteopontin, and galectin-3 genes. Cell apoptosis also was measured in the developing heart.

RESULTS

The thicknesses of the left ventricle walls and the interventricular septum of embryonic hearts exposed to maternal diabetes were significantly thicker than those in the nondiabetic group. Maternal diabetes significantly increased β-myosin heavy chain, atrial natriuretic peptide, insulin-like growth factor-1, and desmin expression, but decreased expression of adrenomedullin. Moreover, collagen synthesis was significantly elevated, whereas fibronectin synthesis was suppressed, in embryonic hearts from diabetic dams, suggesting that cardiac remodeling is a contributing factor to cardiac hypertrophy. The cardiac fibrosis marker, galectin-3, was induced by maternal diabetes. Furthermore, maternal type 2 diabetes mellitus activated the proapoptotic c-Jun-N-terminal kinase 1/2 stress signaling and triggered cell apoptosis by increasing the number of terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells (10.4 ± 2.2% of the type 2 diabetes mellitus group vs 3.8 ± 0.7% of the nondiabetic group, P < .05).

CONCLUSION

Maternal type 2 diabetes mellitus induces cardiac hypertrophy in embryonic hearts. Adverse cardiac remodeling, including elevated collagen synthesis, suppressed fibronectin synthesis, profibrosis, and apoptosis, is implicated as the etiology of cardiac hypertrophy.

microRNA expression profiling and functional annotation analysis of their targets modulated by oxidative stress during embryonic heart development in diabetic mice

Maternal pregestational diabetes mellitus (PGDM) induces congenital heart defects (CHDs). The molecular mechanism underlying PGDM-induced CHDs is unknown. microRNAs (miRNAs), small non-coding RNAs, repress gene expression at the posttranscriptional level and play important roles in heart development. We performed a global miRNA profiling study to assist in revealing potential miRNAs modulated by PGDM and possible developmental pathways regulated by miRNAs during heart development. A total of 149 mapped miRNAs in the developing heart were significantly altered by PGDM. Bioinformatics analysis showed that the majority of the 2111 potential miRNA target genes were associated with cardiac development-related pathways including STAT3 and IGF-1 and transcription factors (Cited2, Zeb2, Mef2c, Smad4 and Ets1). Overexpression of the antioxidant enzyme, superoxide dismutase 1, reversed PGDM-altered miRNAs, suggesting that oxidative stress is responsible for dysregulation of miRNAs. Thus, our study provides the foundation for further investigation of a miRNA-dependent mechanism underlying PGDM-induced CHDs.

The green tea polyphenol EGCG alleviates maternal diabetes-induced neural tube defects by inhibiting DNA hypermethylation

BACKGROUND

Maternal diabetes increases the risk of neural tube defects in offspring. Our previous study demonstrated that the green tea polyphenol, Epigallocatechin gallate, inhibits high glucose-induced neural tube defects in cultured embryos. However, the therapeutic effect of Epigallocatechin gallate on maternal diabetes-induced neural tube defects is still unclear.

OBJECTIVE

We aimed to examine whether Epigallocatechin gallate treatment can reduce maternal diabetes-induced DNA methylation and neural tube defects.

STUDY DESIGN

Nondiabetic and diabetic pregnant mice at embryonic day 5.5 were given drinking water with or without 1 or 10 μM Epigallocatechin gallate. At embryonic day 8.75, embryos were dissected from the visceral yolk sac for the measurement of the levels and activity of DNA methyltransferases, the levels of global DNA methylation, and methylation in the CpG islands of neural tube closure essential gene promoters. embryonic day 10.5 embryos were examined for neural tube defect incidence.

RESULTS

Epigallocatechin gallate treatment did not affect embryonic development because embryos from nondiabetic dams treated with Epigallocatechin gallate did not exhibit any neural tube defects. Treatment with 1 μM Epigallocatechin gallate did not reduce maternal diabetes-induced neural tube defects significantly. Embryos from diabetic dams treated with 10 μM Epigallocatechin gallate had a significantly lower neural tube defect incidence compared with that of embryos without Epigallocatechin gallate treatment. Epigallocatechin gallate reduced neural tube defect rates from 29.5% to 2%, an incidence that is comparable with that of embryos from nondiabetic dams. Ten micromoles of Epigallocatechin gallate treatment blocked maternal diabetes-increased DNA methyltransferases 3a and 3b expression and their activities, leading to the suppression of global DNA hypermethylation. Additionally, 10 μM Epigallocatechin gallate abrogated maternal diabetes-increased DNA methylation in the CpG islands of neural tube closure essential genes, including Grhl3, Pax3, and Tulp3.

CONCLUSION

Epigallocatechin gallate reduces maternal diabetes-induced neural tube defects formation and blocks the enhanced expression and activity of DNA methyltransferases, leading to the suppression of DNA hypermethylation and the restoration of neural tube closure essential gene expression. These observations suggest that Epigallocatechin gallate supplements could mitigate the teratogenic effects of hyperglycemia on the developing embryo and prevent diabetes-induced neural tube defects.

Type 2 diabetes mellitus induces congenital heart defects in murine embryos by increasing oxidative stress, endoplasmic reticulum stress, and apoptosis

BACKGROUND

Maternal type 1 and 2 diabetes mellitus are strongly associated with high rates of severe structural birth defects, including congenital heart defects. Studies in type 1 diabetic embryopathy animal models have demonstrated that cellular stress-induced apoptosis mediates the teratogenicity of maternal diabetes leading to congenital heart defect formation. However, the mechanisms underlying maternal type 2 diabetes mellitus-induced congenital heart defects remain largely unknown.

OBJECTIVE

We aim to determine whether oxidative stress, endoplasmic reticulum stress, and excessive apoptosis are the intracellular molecular mechanisms underlying maternal type 2 diabetes mellitus-induced congenital heart defects.

STUDY DESIGN

A mouse model of maternal type 2 diabetes mellitus was established by feeding female mice a high-fat diet (60% fat). After 15 weeks on the high-fat diet, the mice showed characteristics of maternal type 2 diabetes mellitus. Control dams were either fed a normal diet (10% fat) or the high-fat diet during pregnancy only. Female mice from the high-fat diet group and the 2 control groups were mated with male mice that were fed a normal diet. At E12.5, embryonic hearts were harvested to determine the levels of lipid peroxides and superoxide, endoplasmic reticulum stress markers, cleaved caspase 3 and 8, and apoptosis. E17.5 embryonic hearts were harvested for the detection of congenital heart defect formation using India ink vessel patterning and histological examination.

RESULTS

Maternal type 2 diabetes mellitus significantly induced ventricular septal defects and persistent truncus arteriosus in the developing heart, along with increasing oxidative stress markers, including superoxide and lipid peroxidation; endoplasmic reticulum stress markers, including protein levels of phosphorylated-protein kinase RNA-like endoplasmic reticulum kinase, phosphorylated-IRE1α, phosphorylated-eIF2α, C/EBP homologous protein, and binding immunoglobulin protein; endoplasmic reticulum chaperone gene expression; and XBP1 messenger RNA splicing, as well as increased cleaved caspase 3 and 8 in embryonic hearts. Furthermore, maternal type 2 diabetes mellitus triggered excessive apoptosis in ventricular myocardium, endocardial cushion, and outflow tract of the embryonic heart.

CONCLUSION

Similar to those observations in type 1 diabetic embryopathy, maternal type 2 diabetes mellitus causes heart defects in the developing embryo manifested with oxidative stress, endoplasmic reticulum stress, and excessive apoptosis in heart cells.

Superoxide dismutase 2 overexpression alleviates maternal diabetes-induced neural tube defects, restores mitochondrial function and suppresses cellular stress in diabetic embryopathy

Pregestational diabetes disrupts neurulation leading to neural tube defects (NTDs). Oxidative stress resulting from reactive oxygen species (ROS) plays a central role in the induction of NTD formation in diabetic pregnancies. We aimed to determine whether mitochondrial dysfunction increases ROS production leading to oxidative stress and diabetic embryopathy. Overexpression of the mitochondrion-specific antioxidant enzyme superoxide dismutase 2 (SOD2) in a transgenic (Tg) mouse model significantly reduced maternal diabetes-induced NTDs. SOD2 overexpression abrogated maternal diabetes-induced mitochondrial dysfunction by inhibiting mitochondrial translocation of the pro-apoptotic Bcl-2 family members, reducing the number of defective mitochondria in neuroepithelial cells, and decreasing mitochondrial membrane potential. Furthermore, SOD2 overexpression blocked maternal diabetes-increased ROS production by diminishing dihydroethidium staining signals in the developing neuroepithelium, and reducing the levels of nitrotyrosine-modified proteins and lipid hydroperoxide level in neurulation stage embryos. SOD2 overexpression also abolished maternal diabetes-induced endoplasmic reticulum stress. Finally, caspase-dependent neuroepithelial cell apoptosis enhanced by oxidative stress was significantly reduced by SOD2 overexpression. Thus, our findings support the hypothesis that mitochondrial dysfunction in the developing neuroepithelium enhances ROS production, which leads to oxidative stress and endoplasmic reticulum (ER) stress. SOD2 overexpression blocks maternal diabetes-induced oxidative stress and ER stress, and reduces the incidence of NTDs in embryos exposed to maternal diabetes.

High glucose-induced oxidative stress represses sirtuin deacetylase expression and increases histone acetylation leading to neural tube defects

Aberrant epigenetic modifications are implicated in maternal diabetes-induced neural tube defects (NTDs). Because cellular stress plays a causal role in diabetic embryopathy, we investigated the possible role of the stress-resistant sirtuin (SIRT) family histone deacetylases. Among the seven sirtuins (SIRT1-7), pre-gestational maternal diabetes in vivo or high glucose in vitro significantly reduced the expression of SIRT 2 and SIRT6 in the embryo or neural stem cells, respectively. The down-regulation of SIRT2 and SIRT6 was reversed by superoxide dismutase 1 (SOD1) over-expression in the in vivo mouse model of diabetic embryopathy and the SOD mimetic, tempol and cell permeable SOD, PEGSOD in neural stem cell cultures. 2,3-dimethoxy-1,4-naphthoquinone (DMNQ), a superoxide generating agent, mimicked high glucose-suppressed SIRT2 and SIRT6 expression. The acetylation of histone 3 at lysine residues 56 (H3K56), H3K14, H3K9, and H3K27, putative substrates of SIRT2 and SIRT6, was increased by maternal diabetes in vivo or high glucose in vitro, and these increases were blocked by SOD1 over-expression or tempol treatment. SIRT2 or SIRT6 over-expression abrogated high glucose-suppressed SIRT2 or SIRT6 expression, and prevented the increase in acetylation of their histone substrates. The potent sirtuin activator (SRT1720) blocked high glucose-increased histone acetylation and NTD formation, whereas the combination of a pharmacological SIRT2 inhibitor and a pan SIRT inhibitor mimicked the effect of high glucose on increased histone acetylation and NTD induction. Thus, diabetes in vivo or high glucose in vitro suppresses SIRT2 and SIRT6 expression through oxidative stress, and sirtuin down-regulation-induced histone acetylation may be involved in diabetes-induced NTDs. The mechanism underlying pre-gestational diabetes-induced neural tube defects (NTDs) is still elusive. Our study unravels a new epigenetic mechanism in which maternal diabetes-induced oxidative stress represses sirtuin deacetylase 2 (SIRT2) and 6 (SIRT6) expression leading to histone acetylation and gene expression. SIRT down-regulation mediates the teratogenicity of diabetes leading to (NTD) formation. The study provides a mechanistic basis for the development of natural antioxidants and SIRT activators as therapeutics for diabetic embryopathy.

The Nrf2 Activator Vinylsulfone Reduces High Glucose-Induced Neural Tube Defects by Suppressing Cellular Stress and Apoptosis

The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway is one of the primary pathways responsible for the cellular defense system against oxidative stress. Oxidative stress-induced apoptosis is a causal event in diabetic embryopathy. Thus, the Nrf2 pathway may play an important role in the induction of diabetic embryopathy. In the present study, we investigated the potentially protective effect of the Nrf2 activator, vinylsulfone, on high glucose-induced cellular stress, apoptosis, and neural tube defects (NTDs). Embryonic day 8.5 (E8.5) whole mouse embryos were cultured in normal (5 mmol/L) or high (16.7 mmol/L) glucose conditions, with or without vinylsulfone. At a concentration of 10 μmol/L, vinylsulfone had an inhibitory effect on high glucose-induced NTD formation, but it was not significant. At a concentration of 20 μmol/L, vinylsulfone significantly reduced high glucose-induced NTDs. In addition, 20 μmol/L vinylsulfone abrogated the high glucose-induced oxidative stress markers lipid hydroperoxide (LPO), 4-hydroxynonenal (4-HNE), and nitrotyrosine-modified proteins. The high glucose-induced endoplasmic reticulum (ER) stress biomarkers were also suppressed by 20 μmol/L vinylsulfone through the inhibition of phosphorylated protein kinase RNA-like ER kinase (PERK), inositol requiring protein 1α (IRE1a), eukaryotic initiation factor 2α (eIF2a), upregulated C/EBP-homologous protein (CHOP), binding immunoglobulin protein (BiP), and x-box binding protein 1 (XBP1) messenger RNA splicing. Furthermore, 20 μmol/L vinylsulfone abolished caspase 3 and caspase 8 cleavage, markers of apoptosis, in embryos cultured under high glucose conditions. The Nrf2 activator, vinylsulfone, is protective against high glucose-induced cellular stress, caspase activation, and subsequent NTD formation. Our data suggest that vinylsulfone supplementation is a potential therapy for diabetes-associated neurodevelopmental defects.