N-Acetylcysteine prevents congenital heart defects induced by pregestational diabetes

Hydrogen sulfide mitigates mitochondrial dysfunction and cellular senescence in diabetic patients: Potential therapeutic applications

Diabetes induces a pro-aging state characterized by an increased abundance of senescent cells in various tissues, heightened chronic inflammation, reduced substance and energy metabolism, and a significant increase in intracellular reactive oxygen species (ROS) levels. This condition leads to mitochondrial dysfunction, including elevated oxidative stress, the accumulation of mitochondrial DNA (mtDNA) damage, mitophagy defects, dysregulation of mitochondrial dynamics, and abnormal energy metabolism. These dysfunctions result in intracellular calcium ion (Ca2+) homeostasis disorders, telomere shortening, immune cell damage, and exacerbated inflammation, accelerating the aging of diabetic cells or tissues. Hydrogen sulfide (H2S), a novel gaseous signaling molecule, plays a crucial role in maintaining mitochondrial function and mitigating the aging process in diabetic cells. This article systematically explores the specific mechanisms by which H2S regulates diabetes-induced mitochondrial dysfunction to delay cellular senescence, offering a promising new strategy for improving diabetes and its complications.

Insights into the developmental and cardiovascular toxicity of bixafen using zebrafish embryos and larvae

Bixafen (BIX), a member of the succinate dehydrogenase inhibitor (SDHI) class of fungicides, has seen a surge in interest due to its expanding market presence and positive development outlook. However, there is a growing concern about its potential harm to aquatic life, largely due to its resistance to breaking down in the environment. In this study, we thoroughly examined the toxicological impact of BIX on zebrafish as a model organism. Our results revealed that BIX significantly hindered the development of zebrafish embryos, leading to increased mortality, hatching failures, and oxidative stress. Additionally, we observed cardiovascular abnormalities, including dilated cardiac chambers, reduced heart rate, sluggish blood circulation, and impaired vascular function. Notably, BIX also altered the expression of key genes involved in cardiovascular development, such as myl7, vmhc, nkx2.5, tbx5, and flt1. In summary, BIX was found to induce developmental and cardiovascular toxicity in zebrafish, underscoring the risks associated with SDHI pesticides and emphasizing the need for a reassessment of their impact on human health. These findings are crucial for the responsible use of BIX.

Early Methylglyoxal Exposure Leads to Worsened Cardiovascular Function in Young Rats

BACKGROUND

Though maternal diabetes effects are well described in the literature, the effects of maternal diabetes in postnatal phases are often overlooked. Diabetic individuals have higher levels of circulating glycotoxins, and there is a positive correlation between maternal-derived glycotoxins and circulating glycotoxins in their progeny. Previous studies evaluated the metabolic effects of high glycotoxin exposure during lactation in adult animals. However, here we focus on the cardiovascular system of juvenile rats.

METHODS

For this, we used two experimental models: 1. High Methylglyoxal (MG) environment: pregnant Wistar rats were injected with PBS (VEH group) or Methylglyoxal (MG group; 60 mg/kg/day; orally, postnatal day (PND) 3 to PND14). 2. GLO-1 inhibition: pregnant Wistar rats were injected with dimethyl sulfoxide (VEH group) or a GLO-1 inhibitor (BBGC group; 5 mg/kg/day; subcutaneously, PND1-PND5). The offspring were evaluated at PND45.

RESULTS

MG offspring presented cardiac dysfunction and subtly worsened vasomotor responses in the presence of perivascular adipose tissue, without morphological alterations. In addition, an endogenous increase in maternal glycotoxins impacts offspring vasomotricity due to impaired redox status.

CONCLUSIONS

Our data suggest that early glycotoxin exposure led to cardiac and vascular impairments, which may increase the risk for developing cardiovascular diseases later in life.

A fetal rat model of ventricular noncompaction caused by intrauterine hyperglycemia

BACKGROUND

This study aims to develop a fetal rat model of ventricular noncompaction (NVM) using streptozotocin (STZ)-induced gestational hyperglycemia and compare it with a retinoic acid (RA) model.

METHODS

Female SD rats were categorized into STZ, RA, and normal control (NC) groups. The STZ group was given a high-fat diet pre-pregnancy and 35 mg/kg of 2% STZ postpregnancy. The RA group received a 90 mg/kg dose of RA on day 13 postpregnancy. Embryonic myocardial morphology was analyzed through HE staining, and embryonic cardiomyocyte ultrastructures were studied using electron microscopy. Diagnoses of NVM were based on a ratio of noncompact myocardium (N) to compact myocardium (C) >1.4, accompanied by thick myocardial trabeculae and a thin myocardial compaction layer. Kruskal-Wallis test determined N/C ratio differences among groups.

RESULTS

Both STZ and RA groups displayed significant NVM characteristics. The left ventricular (LV) N/C in the STZ, RA, and NC groups were 1.983 (1.423-3.527), 1.640 (1.197-2.895), and 0.927 (0.806-1.087), respectively, with a statistically significant difference (P<0.001). The right ventricular (RV) N/C in the STZ, RA, and NC groups were 2.097 (1.364-3.081), 1.897 (1.337-2.662), and 0.869 (0.732-1.022), respectively, with a significant difference (P<0.001). Electron microscopy highlighted marked endoplasmic reticulum swelling in embryonic cardiomyocytes from both STZ and RA groups.

CONCLUSION

Our model underscores the pivotal role of an adverse intrauterine developmental environment in the onset of NVM. This insight holds significant implications for future studies exploring the pathogenesis of NVM.

Risk of major congenital heart disease in pregestational maternal diabetes is modified by hemoglobin A1c

OBJECTIVES

The association between pregestational diabetes mellitus (PDM) and risk of congenital heart disease (CHD) is well recognized; however, the importance of glycemic control and other coexisting risk factors during pregnancy is less clear. We sought to determine the relative risk (RR) of major CHD (mCHD) among offspring from pregnancies complicated by PDM and the effect of first-trimester glycemic control on mCHD risk.

METHODS

We determined the incidence of mCHD (requiring surgery within 1 year of birth or resulting in pregnancy termination or fetal demise) among registered births in Alberta, Canada. Linkage of diabetes status, maximum hemoglobin A1c (HbA1c) at < 16 weeks' gestation and other covariates was performed using data from the Alberta Perinatal Health Program registry. Risk of mCHD according to HbA1c was estimated as an adjusted RR (aRR), calculated using log-binomial modeling.

RESULTS

Of 1412 cases of mCHD in 594 773 (2.37/1000) births in the study period, mCHD was present in 48/7497 with PDM (6.4/1000; RR, 2.8 (95% CI, 2.1-3.7); P < 0.0001). In the entire cohort, increased maternal age (aRR, 1.03 (95% CI, 1.02-1.04); P < 0.0001) and multiple gestation (aRR, 1.37 (95% CI, 1.1-1.8); P = 0.02) were also associated with mCHD risk, whereas maternal prepregnancy weight > 91 kg was not. The stratified risk for mCHD associated with HbA1c ≤ 6.1%, > 6.1-8.0% and > 8.0% was 4.2/1000, 6.8/1000 and 17.1/1000 PDM/gestational diabetes mellitus births, respectively; the aRR of mCHD associated with PDM and HbA1c > 8.0% was 8.5 (95% CI, 5.0-14.4) compared to those without diabetes and 5.5 (95% CI, 1.6-19.4) compared to PDM with normal HbA1c (≤ 6.1%).

CONCLUSIONS

PDM is associated with a RR of 2.8 for mCHD, increasing to 8.5 in those with HbA1c > 8%. These data should facilitate refinement of referral indications for high-risk pregnancy screening. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Modulation of cAMP/cGMP signaling as prevention of congenital heart defects in Pde2A deficient embryos: a matter of oxidative stress

Phosphodiesterase 2A (Pde2A) is a dual-specific PDE that breaks down both cAMP and cGMP cyclic nucleotides. We recently highlighted a direct relationship between Pde2A impairment, a consequent increase of cAMP, and the appearance of mouse congenital heart defects (CHDs). Here we aimed to characterize the pathways involved in the development of CHDs and in their prevention by pharmacological approaches targeting cAMP and cGMP signaling. Transcriptome analysis revealed a modulation of more than 500 genes affecting biological processes involved in the immune system, cardiomyocyte development and contractility, angiogenesis, transcription, and oxidative stress in hearts from Pde2A-/- embryos. Metoprolol and H89 pharmacological administration prevented heart dilatation and hypertabeculation in Pde2A-/- embryos. Metoprolol was also able to partially impede heart septum defect and oxidative stress at tissue and molecular levels. Amelioration of cardiac defects was also observed by using the antioxidant NAC, indicating oxidative stress as one of the molecular mechanisms underpinning the CHDs. In addition, Sildenafil treatment recovered cardiac defects suggesting the requirement of cAMP/cGMP nucleotides balance for the correct heart development.

Single Cell Multimodal Analyses Reveal Epigenomic and Transcriptomic Basis for Birth Defects in Maternal Diabetes

Maternal diabetes mellitus is among the most frequent environmental contributors to congenital birth defects, including heart defects and craniofacial anomalies, yet the cell types affected and mechanisms of disruption are largely unknown. Using multi-modal single cell analyses, here we show that maternal diabetes affects the epigenomic landscape of specific subsets of cardiac and craniofacial progenitors during embryogenesis. A previously unrecognized cardiac progenitor subpopulation expressing the homeodomain-containing protein ALX3 showed prominent chromatin accessibility changes and acquired a more posterior identity. Similarly, a subpopulation of neural crest-derived cells in the second pharyngeal arch, which contributes to craniofacial structures, displayed abnormalities in the epigenetic landscape and axial patterning defects. Chromatin accessibility changes in both populations were associated with increased retinoic acid signaling, known to establish anterior-posterior identity. This work highlights how an environmental insult can have highly selective epigenomic consequences on discrete cell types leading to developmental patterning defects.

Maternal Pre-Existing Diabetes: A Non-Inherited Risk Factor for Congenital Cardiopathies

Congenital heart defects (CHDs) are the most common form of birth defects in humans. They occur in 9 out of 1000 live births and are defined as structural abnormalities of the heart. Understanding CHDs is difficult due to the heterogeneity of the disease and its multifactorial etiology. Advances in genomic sequencing have made it possible to identify the genetic factors involved in CHDs. However, genetic origins have only been found in a minority of CHD cases, suggesting the contribution of non-inherited (environmental) risk factors to the etiology of CHDs. Maternal pregestational diabetes is associated with a three- to five-fold increased risk of congenital cardiopathies, but the underlying molecular mechanisms are incompletely understood. According to current hypotheses, hyperglycemia is the main teratogenic agent in diabetic pregnancies. It is thought to induce cell damage, directly through genetic and epigenetic dysregulations and/or indirectly through production of reactive oxygen species (ROS). The purpose of this review is to summarize key findings on the molecular mechanisms altered in cardiac development during exposure to hyperglycemic conditions in utero. It also presents the various in vivo and in vitro techniques used to experimentally model pregestational diabetes. Finally, new approaches are suggested to broaden our understanding of the subject and develop new prevention strategies.

Maternal diabetes increases FOXO1 activation during embryonic cardiac development

Maternal diabetes is known to affect heart development, inducing the programming of cardiac alterations in the offspring's adult life. Previous studies in the heart of adult offspring have shown increased activation of FOXO1 (a transcription factor involved in a wide variety of cellular functions such as apoptosis, cellular proliferation, reactive oxygen species detoxification, and antioxidant and pro-inflammatory processes) and of target genes related to inflammatory and fibrotic processes. In this work, we aimed to evaluate the effects of maternal diabetes on FOXO1 activation as well as on the expression of target genes relevant to the formation of the cardiovascular system during organogenesis (day 12 of gestation). The embryonic heart from diabetic rats showed increased active FOXO1 levels, reduced protein levels of mTOR (a nutrient sensor regulating cell growth, proliferation and metabolism) and reduced mTORC2-SGK1 pathway, which phosphorylates FOXO1. These alterations were related to increases in the levels of 4-hydroxynonenal (an oxidative stress marker) and increased mRNA levels of inducible nitric oxide synthase, angiopoietin-2 and matrix metalloproteinase-2 (MMP2) (all FOXO1 target genes relevant for cardiac development). Results also showed increased extracellular and intracellular immunolocalization of MMP2 in the myocardium and its projection into the lumen of the cavity (trabeculations) together with decreased immunostaining of connexin 43, a protein relevant for cardiac function that is target of MMP2. In conclusion, increases in active FOXO1 induced by maternal diabetes initiate early during embryonic heart development and are related to increases in markers of oxidative stress and of proinflammatory cardiac development, as well to an altered expression of proteolytic enzymes that regulate connexin 43. These alterations may lead to an altered programming of cardiovascular development in the embryonic heart of diabetic rats.

Organosulfurs, S-allyl cysteine and N-acetyl cysteine sequester di-carbonyls and reduces carbonyl stress in HT22 cells

Diabetes, characterized by high blood glucose level, is a progressive metabolic disease that leads to serious health complications. One of the major pathological consequences associated with diabetes is the accumulation of highly reactive carbonyl compounds called advanced glycation end products (AGEs). Most of the AGEs are dicarbonyls and have the potential to covalently modify proteins especially at the lysine residues in a non-enzymatic fashion (a process termed as glycation) resulting in the functional impairment and/or toxic gain in function. Therefore, non-toxic small molecules that can inhibit glycation are of interest for the therapeutic intervention of diabetes. In the present communication, we have investigated the effect of organosulfurs (S-allyl cysteine, SAC and N-acetyl cysteine, NAC) that are major principal components of Allium sativa against the glycation of different proteins. We discovered that both SAC and NAC are potent anti-glycating agents. We also found that both SAC and NAC reduce ROS level and inhibit apoptosis caused by protein glycation.

Developmental and cardiac toxicity assessment of Ethyl 3-(N-butylacetamido) propanoate (EBAAP) in zebrafish embryos

Ethyl 3-(N-butylacetamido) propanoate (EBAAP) is one of the most widely used mosquito repellents worldwide, and is also commonly used to produce cosmetics. Residues have recently been detected in surface and groundwater in many countries, and their potential to harm the environment is unknown. Therefore, more studies are needed to fully assess the toxicity of EBAAP. This is the first investigation into the developmental toxicity and cardiotoxicity of EBAAP on zebrafish embryos. EBAAP was toxic to zebrafish, with a lethal concentration 50 (LC50) of 140 mg/L at 72 hours post fertilization (hpf). EBAAP exposure also reduced body length, slowed the yolk absorption rate, induced spinal curvature and pericardial edema, decreased heart rate, promoted linear lengthening of the heart, and diminished cardiac pumping ability. The expression of heart developmental-related genes (nkx2.5, myh6, tbx5a, vmhc, gata4, tbx2b) was dysregulated, intracellular oxidative stress increased significantly, the activities of catalase (CAT) and superoxide dismutase (SOD) decreased, and malondialdehyde (MDA) content increased significantly. The expression of apoptosis-related genes (bax/bcl2, p53, caspase9, caspase3) was significantly upregulated. In conclusion, EBAAP induced abnormal morphology and heart defects during the early stages of zebrafish embryo development by potentially inducing the generation and accumulation of reactive oxygen species (ROS) in vivo and activating the oxidative stress response. These events dysregulate the expression of several genes and activate endogenous apoptosis pathways, eventually leading to developmental disorders and heart defects.

Research Progress of Maternal Metabolism on Cardiac Development and Function in Offspring

The developmental origin of health and disease (DOHaD) hypothesis refers to the adverse effects of suboptimal developmental environments during embryonic and early fetal stages on the long-term health of offspring. Intrauterine metabolic perturbations can profoundly impact organogenesis in offspring, particularly affecting cardiac development and giving rise to potential structural and functional abnormalities. In this discussion, we contemplate the existing understanding regarding the impact of maternal metabolic disorders, such as obesity, diabetes, or undernutrition, on the developmental and functional aspects of the offspring's heart. This influence has the potential to contribute to the susceptibility of offspring to cardiovascular health issues. Alteration in the nutritional milieu can influence mitochondrial function in the developing hearts of offspring, while also serving as signaling molecules that directly modulate gene expression. Moreover, metabolic disorders can exert influence on cardiac development-related genes epigenetically through DNA methylation, levels of histone modifications, microRNA expression, and other factors. However, the comprehensive understanding of the mechanistic underpinnings of these phenomena remains incomplete. Further investigations in this domain hold profound clinical significance, as they can contribute to the enhancement of public health and the prevention of cardiovascular diseases.

Pre-gestational diabetes and the risk of congenital heart defects in the offspring: A French nationwide study

AIM

To compare the frequencies and types of congenital heart defects for infants of women without and with pre-gestational diabetes, type 1 and type 2 diabetes (T1DM, T2DM) and to identify risk factors.

METHODS

All live births between 2012 and 2020 were screened for maternal diabetes and infant congenital heart defects using the French Medical Information System Program in Medicine, Surgery and Obstetrics database (PMSI-MCO). Incidences of these defects were estimated, and a logistic model evaluated maternal and fetal prognostic risk factors.

RESULTS

Overall, 6,038,703 mothers did not have pre-gestational diabetes (no-diabetes), 23,147 had T1DM, and 14,401 had T2DM. The incidence of infant congenital disease was 6.2% for the no-diabetes group, 8.0%, for women with T1DM, and 8.4% for women with T2DM (P < 0.001); for congenital heart defects, incidences were respectively 0.8%, 3.0% and 2.7% (P < 0.001). In comparison with the no-diabetes group, the odds ratios (95%CI) of coronary heart defects were 2.07 (1.91;2.24) (P < 0.001) for women with T1DM and 2.20 (1.99;2.44) (P < 0.001) for women with T2DM, with no difference between T1DM and T2DM (P = 0.336). cesarian section, small and large for gestational age, and prematurity were also associated with an increased risk of congenital heart defects.

CONCLUSION

In this study we observed higher incidences of congenital heart defects in infants of women with pre-gestational diabetes compared to women without pre-gestational diabetes, with no difference between women with T1DM or T2DM. These data call for intensifying preconception care and justify systematic cardiac echography in selected fetuses.

PM2.5 induces cardiac malformations via PI3K/akt2/mTORC1 signaling pathway in zebrafish larvae

Growing evidence indicates that maternal fine particulate matter (PM2.5) exposure is linked with congenital heart diseases in the offspring. To explore the underlying molecular mechanisms, we tested the effects of a number of pharmaceutical inhibitors, and found that suppressing the PI3K/akt signaling pathway had a protective effect against cardiac defects in zebrafish larvae exposed to extractable organic matter (EOM) from PM2.5. Using genetic knockdown and a specific akt2 pharmacological inhibitor, CCT128930, we demonstrated that akt2 activation is essential to EOM-induced heart malformations. Next, we found that the EOM-induced akt2 overactivation enhances intracellular reactive oxygen species (ROS)/mitochondrial ROS production, decreases mitochondrial membrane potential levels, and elicits intrinsic apoptosis in the heart of zebrafish embryos. In addition, EOM-induced akt2 activation decreased active β-catenin levels and inhibited the expression of Wnt target genes axin2 and nkx2.5. We further demonstrated that mTORC1 phosphorylation mediates the adverse effects of akt2 on intrinsic apoptosis and canonical Wnt signaling in the heart of zebrafish larvae exposed to EOM. Moreover, EOM-induced akt2 activation is mediated via aryl hydrocarbon receptor (AHR)/ROS-induced PTEN inhibition. In conclusion, our results indicate that PM2.5 activates PI3K/akt2/mTORC1 signaling via AHR/ROS-induced PTEN suppression, which leads to mitochondrial-mediated intrinsic apoptosis and Wnt signaling suppression, resulting in cardiac defects in zebrafish larvae.

Effect of maternal pregestational diabetes mellitus on congenital heart diseases

BACKGROUND

The increasing population of diabetes mellitus in adolescent girls and women of childbearing age contributes to a large number of pregnancies with maternal pregestational diabetes mellitus. Congenital heart diseases are a common adverse outcome in mothers with pregestational diabetes mellitus. However, there is little systematic information between maternal pregestational diabetes mellitus and congenital heart diseases in the offspring.

DATA SOURCES

Literature selection was performed in PubMed. One hundred and seven papers were cited in our review, including 36 clinical studies, 26 experimental studies, 31 reviews, eight meta-analysis articles, and six of other types.

RESULTS

Maternal pregestational diabetes mellitus poses a high risk of congenital heart diseases in the offspring and causes variety of phenotypes of congenital heart diseases. Factors such as persistent maternal hyperglycemia, oxidative stress, polymorphism of uncoupling protein 2, polymorphism of adiponectin gene, Notch 1 pathway, Nkx2.5 disorders, dysregulation of the hypoxia-inducible factor 1, and viral etiologies are associated with the occurrence of congenital heart diseases in the offspring of mothers with pregestational diabetes mellitus. Treatment options including blood sugar-reducing, anti-oxidative stress drug supplements and exercise can help to prevent maternal pregestational diabetes mellitus from inducing congenital heart diseases.

CONCLUSIONS

Our review contributes to a better understanding of the association between maternal pregestational diabetes mellitus and congenital heart diseases in the offspring and to a profound thought of the mechanism, preventive and therapeutic measurements of congenital heart diseases caused by maternal pregestational diabetes mellitus.

Novel circRNA-miRNA-mRNA networks regulated by maternal exercise in fetal hearts of pregestational diabetes

BACKGROUND

Maternal exercise lowers the incidence of congenital heart defects (CHDs) induced by pregestational diabetes. However, the molecular mechanisms underlying the beneficial effects of maternal exercise remain unclear. The present study aimed to identify circular RNA (circRNA), microRNA (miRNA) and mRNA networks that are regulated by maternal exercise in fetal hearts of pregestational diabetes.

METHODS

Pregestational diabetes was induced in adult C57BL/6 female mice by streptozotocin. The expression profiles of circRNAs, miRNAs and mRNAs in E10.5 fetal hearts of offspring of control and diabetic mothers with or without exercise were analyzed using next generation sequencing. circRNA-miRNA-mRNA networks in fetal hearts were mapped and key candidate transcripts were verified by qPCR analysis.

RESULTS

Pregestational diabetes dysregulated the expression of 206 circRNAs, 66 miRNAs and 391 mRNAs in fetal hearts. Maternal exercise differentially regulated 188 circRNAs, 57 miRNAs and 506 mRNAs in fetal hearts of offspring of pregestational diabetes. A total of 5 circRNAs, 12 miRNAs, and 28 mRNAs were incorporated into a final maternal exercise-associated regulatory network in fetal hearts of offspring of maternal diabetes. Notably, maternal exercise normalized the dysregulated circ_0003226/circ_0015638/miR-351-5p and circ_0002768/miR-3102-3p.2-3p pairs in fetal hearts of pregestational diabetes.

CONCLUSION

Maternal exercise reverses the dysregulated circ_0003226/circ_0015638/miR-351-5p and circ_0002768/miR-3102-3p.2-3p pairs, and partially normalizes circRNA, miRNA, and mRNA expression profiles in fetal hearts of pregestational diabetes. These findings shed new light on the potential mechanisms of the beneficial effects of maternal exercise on the developing heart in diabetic pregnancies.

Fine particulate matter induces heart defects via AHR/ROS-mediated endoplasmic reticulum stress

Accumulating body of evidence indicates that exposure to fine particulate matter (PM_2.5) is closely associated with congenital heart disease in the offspring, but the underlying molecular mechanisms remain to be elucidated. We previously reported that extractable organic matter (EOM) from PM_2.5 induces reactive oxygen species (ROS) overproduction by activating aromatic hydrocarbon receptor (AHR), leading to heart defects in zebrafish embryos. We hypothesized that endoplasmic reticulum (ER) stress might be elicited by the excessive ROS production and thereby contribute to the cardiac developmental toxicity of PM_2.5. In this study, we examined the effects of EOM on endoplasmic reticulum (ER) stress, apoptosis, and Wnt signal pathway in zebrafish embryos, and explored their roles in EOM-induced heart defects. Our results showed that 4-Phenylbutyric acid (4-PBA), a pharmaceutical inhibitor of ER stress, significantly attenuated the EOM-elevated heart malformation rates. Moreover, EOM upregulated the expression levels of ER stress marker genes including CHOP and PDI in the heart of zebrafish embryos, which were counteracted by genetic or pharmaceutical inhibition of AHR activity. The ROS scavenger N-Acetyl-l-cysteine (NAC) also abolished the EOM-induced ER stress. We further demonstrated that both 4-PBA and CHOP genetic knockdown rescued the PM_2.5-induced ROS overproduction, apoptosis and suppression of Wnt signaling. In conclusion, our results indicate that PM_2.5 induces AHR/ROS-mediated ER stress, which leads to apoptosis and Wnt signaling inhibition, ultimately resulting in heart defects.

Pregestational diabetes alters cardiac structure and function of neonatal rats through developmental plasticity

Pregestational diabetes (PGDM) leads to developmental impairment, especially cardiac dysfunction, in their offspring. The hyperglycemic microenvironment inside the uterus alters the cardiac plasticity characterized by electrical and structural remodeling of the heart. The altered expression of several transcription factors due to hyperglycemia during fetal development might be responsible for molecular defects and phenotypic changes in the heart. The molecular mechanism of the developmental defects in the heart due to PGDM remains unclear. To understand the molecular defects in the 2-days old neonatal rats, streptozotocin-induced diabetic female rats were bred with healthy male rats. We collected 2-day-old hearts from the neonates and identified the molecular basis for phenotypic changes. Neonates from diabetic mothers showed altered electrocardiography and echocardiography parameters. Transcriptomic profiling of the RNA-seq data revealed that several altered genes were associated with heart development, myocardial fibrosis, cardiac conduction, and cell proliferation. Histopathology data showed the presence of focal cardiac fibrosis and increased cell proliferation in neonates from diabetic mothers. Thus, our results provide a comprehensive map of the cellular events and molecular pathways perturbed in the neonatal heart during PGDM. All of the molecular and structural changes lead to developmental plasticity in neonatal rat hearts and develop cardiac anomalies in their early life.

Tripeptide Leu-Pro-Phe from Corn Protein Hydrolysates Attenuates Hyperglycemia-Induced Neural Tube Defect in Chicken Embryos

Neural tube defect (NTD) is the most common and severe embryopathy causing embryonic malformation and even death associated with gestational diabetes mellitus (GDM). Leu-Pro-Phe (LPF) is an antioxidative tripeptide isolated from hydrolysates of corn protein. However, the biological activity of LPF in vivo and in vitro remains unclear. This study is aimed at investigating the protective effects of tripeptide LPF against NTD in the high glucose exposure condition and delineate the underlying biological mechanism. We found that LPF alleviated NTD in the high glucose-exposed chicken embryo model. In addition, DF-1 chicken embryo fibroblast was loaded with high glucose for induction of oxidative stress and abnormal O-GlcNAcylation in vitro. LPF significantly decreased accumulation of reactive oxygen species and content of malondialdehyde in DF-1 cells but increased the ratio of reduced glutathione and oxidized glutathione in chick embryo. Oxygen radical absorbance capacity results showed that LPF itself had good free radical scavenging capacity and could enhance antioxidant activity of the cell content. Mechanistic studies suggested that the resistance of LPF to oxidative damage may be related to promotion of NRF2 expression and nuclear translocation. LPF alleviated the overall O-GlcNAcylation level of cellular proteins under high glucose conditions and restored the level of Pax3 protein. Collectively, our findings indicate that LPF peptide could act as a nutritional supplement for the protection of development of embryonic neural tube affected by GDM.

Modeling the Effects of Maternal Diabetes on the Developing Human Heart Using Pluripotent Stem Cell-Derived Heart Organoids

Congenital heart defects (CHD) constitute the most common type of birth defect in humans. Maternal diabetes during the first trimester of pregnancy (pregestational diabetes, or PGD) is one of the most prominent factors contributing to CHD, and is present in a significant population of female patients with diabetes in reproductive age. PGD is challenging to manage clinically due to the extreme sensitivity of the developing embryo to glucose oscillations, and constitutes a critical health problem for the mother and the fetus. The prevalence of PGD-induced CHD is increasing due to the ongoing diabetes epidemic. While studies using animal models and cells in culture have demonstrated that PGD alters critical cellular and developmental processes, the mechanisms remain obscure, and it is unclear to what extent these models recapitulate PGD-induced CHD in humans. Clinical practice precludes direct studies in developing human embryos, further highlighting the need for physiologically relevant models. To bypass many of these technical and ethical limitations, we describe here a human pluripotent stem cell (hPSC)-based method to generate developmentally relevant self-organizing human heart organoids. By using glucose and insulin to mimic the diabetic environment that the embryo faces in PGD, this system allows modeling critical features of PGD in a human system with relevant physiology, structure, and cell types. The protocol starts with the generation of hPSC-derived embryoid bodies in a 96-well plate, followed by a small molecule-based three-step Wnt activation/inhibition/activation strategy. Organoids are then differentiated under healthy (normal insulin and glucose) and diabetic conditions (high insulin and glucose) over time, allowing for the study of the effects of pregestational diabetes on the developing human heart. We also provide an immunofluorescence protocol for comparing, characterizing, and analyzing the differences between the healthy and diabetic organoids, and comment on additional steps for preparing the organoids for analysis by other techniques after differentiation. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Generation of hPSC-derived embryoid bodies Basic Protocol 2: Differentiation of EBs into heart organoids under healthy and diabetes-like conditions Basic Protocol 3: Immunofluorescence and organoid preparation for other assays.

Maternal nicotine exposure induces congenital heart defects in the offspring of mice

Maternal cigarette smoking is a risk factor for congenital heart defects (CHDs). Nicotine replacement therapies are often offered to pregnant women following failed attempts of smoking cessation. However, the impact of nicotine on embryonic heart development is not well understood. In the present study, the effects of maternal nicotine exposure (MNE) during pregnancy on foetal heart morphogenesis were studied. Adult female mice were treated with nicotine using subcutaneous osmotic pumps at 0.75 or 1.5 mg/kg/day and subsequently bred with male mice. Our results show that MNE dose-dependently increased CHDs in foetal mice. CHDs included atrial and ventricular septal defects, double outlet right ventricle, unguarded tricuspid orifice, hypoplastic left ventricle, thickened aortic and pulmonary valves, and ventricular hypertrophy. MNE also significantly reduced coronary artery size and vessel abundance in foetal hearts. Moreover, MNE resulted in higher levels of oxidative stress and altered the expression of key cardiogenic regulators in the developing heart. Nicotine exposure reduced epicardial-to-mesenchymal transition in foetal hearts. In conclusion, MNE induces CHDs and coronary artery malformation in mice. These findings provide insight into the adverse outcomes of foetuses by MNE during pregnancy.

Congenital Abnormalities in the Infant of a Diabetic Mother

Diabetes mellitus is among the most common chronic diseases worldwide. Infants of diabetic mothers are at increased risk of having congenital abnormalities. Tremendous progress has been achieved in the pregnancy care of diabetic women; however, the risk of birth defects associated with maternal diabetes still exists. These anomalies might arise in many organs and systems of the developing fetus. Many mechanisms have been implicated in the teratogenicity of maternal diabetes and it is critical to achieve good glycemic control before conception in women with diabetes. Neonatal clinicians must be able to identify patients at risk and recognize the signs of diabetic embryopathy. This article presents a review of congenital anomalies associated with maternal diabetes.

Impact of maternal hyperglycemia on cardiac development: Insights from animal models

Congenital heart disease (CHD) is the leading cause of birth defect-related death in infants and is a global pediatric health concern. While the genetic causes of CHD have become increasingly recognized with advances in genome sequencing technologies, the etiology for the majority of cases of CHD is unknown. The maternal environment during embryogenesis has a profound impact on cardiac development, and numerous environmental factors are associated with an elevated risk of CHD. Maternal diabetes mellitus (matDM) is associated with up to a fivefold increased risk of having an infant with CHD. The rising prevalence of diabetes mellitus has led to a growing interest in the use of experimental diabetic models to elucidate mechanisms underlying this associated risk for CHD. The purpose of this review is to provide a comprehensive summary of rodent models that are being used to investigate alterations in cardiac developmental pathways when exposed to a maternal diabetic setting and to summarize the key findings from these models. The majority of studies in the field have utilized the chemically induced model of matDM, but recent advances have also been made using diet based and genetic models. Each model provides an opportunity to investigate unique aspects of matDM and is invaluable for a comprehensive understanding of the molecular and cellular mechanisms underlying matDM-associated CHD.

Cardiac toxicity assessment of pendimethalin in zebrafish embryos

Pendimethalin (PND) is one of the best sellers of selective herbicide in the world and has been frequently detected in the water. However, little is known about its effects on cardiac development. In this study, we used zebrafish to investigate the developmental and cardiac toxicity of PND. We exposed the zebrafish embryos with a serial of concentrations at 3, 4, and 5 mg/L at 5.5-72 h post-fertilization (hpf). We found that PND exposure can reduce the heart rate, survival rate, and body length of zebrafish embryos. Furthermore, we identified many malformations including pericardial and yolk sac edema, spinal deformity, and cardiac looping abnormality. In addition, PND increased the expression of reactive oxygen species and malondialdehyde and reduced the activity of superoxide dismutase (Antioxidant enzymes); We examined the expression of cardiac development-related genes and the apoptosis markers, and found changes of the following marker: vmhc, nppa, tbx5a, nkx2.5, gata4, tbx2b and FoxO1, bax, bcl-2, p53, casp-9, casp-3. Our data showed that activation of Wnt pathway can rescue the cardiac abnormalities caused by PND. Our results provided new evidence for the toxicity of PND and suggested that the PND residual should be treated as a hazard in the environment.

Self-assembling human heart organoids for the modeling of cardiac development and congenital heart disease

Congenital heart defects constitute the most common human birth defect, however understanding of how these disorders originate is limited by our ability to model the human heart accurately in vitro. Here we report a method to generate developmentally relevant human heart organoids by self-assembly using human pluripotent stem cells. Our procedure is fully defined, efficient, reproducible, and compatible with high-content approaches. Organoids are generated through a three-step Wnt signaling modulation strategy using chemical inhibitors and growth factors. Heart organoids are comparable to age-matched human fetal cardiac tissues at the transcriptomic, structural, and cellular level. They develop sophisticated internal chambers with well-organized multi-lineage cardiac cell types, recapitulate heart field formation and atrioventricular specification, develop a complex vasculature, and exhibit robust functional activity. We also show that our organoid platform can recreate complex metabolic disorders associated with congenital heart defects, as demonstrated by an in vitro model of pregestational diabetes-induced congenital heart defects.

Mechanisms of Impaired Lung Development and Ciliation in Mannosidase-1-Alpha-2 (Man1a2) Mutants

BACKGROUND

Ciliary defects cause heterogenous phenotypes related to mutation burden which lead to impaired development. A previously reported homozygous deletion in the Man1a2 gene causes lethal respiratory failure in newborn pups and decreased lung ciliation compared with wild type (WT) pups. The effects of heterozygous mutation, and the potential for rescue are not known.

PURPOSE

We hypothesized that survival and lung ciliation, (a) would decrease progressively in Man1a2 +/- heterozygous and Man1a2 -/- null newborn pups compared with WT, and (b) could be enhanced by gestational treatment with N-Acetyl-cysteine (NAC), an antioxidant.

METHODS

Man1a2+/- adult mice were fed NAC or placebo from a week before breeding through gestation. Survival of newborn pups was monitored for 24 h. Lungs, liver and tails were harvested for morphology, genotyping, and transcriptional profiling.

RESULTS

Survival (p = 0.0001, Kaplan-Meier) and percent lung ciliation (p = 0.0001, ANOVA) measured by frequency of Arl13b+ respiratory epithelial cells decreased progressively, as hypothesized. Compared with placebo, gestational NAC treatment enhanced (a) lung ciliation in pups with each genotype, (b) survival in heterozygous pups (p = 0.017) but not in WT or null pups. Whole transcriptome of lung but not liver demonstrated patterns of up- and down-regulated genes that were identical in living heterozygous and WT pups, and completely opposite to those in dead heterozygous and null pups. Systems biology analysis enabled reconstruction of protein interaction networks that yielded functionally relevant modules and their interactions. In these networks, the mutant Man1a2 enzyme contributes to abnormal synthesis of proteins essential for lung development. The associated unfolded protein, hypoxic and oxidative stress responses can be mitigated with NAC. Comparisons with the developing human fetal lung transcriptome show that NAC likely restores normal vascular and epithelial tube morphogenesis in Man1a2 mutant mice.

CONCLUSION

Survival and lung ciliation in the Man1a2 mutant mouse, and its improvement with N-Acetyl cysteine is genotype-dependent. NAC-mediated rescue depends on the central role for oxidative and hypoxic stress in regulating ciliary function and organogenesis during development.

The role of glucose in physiological and pathological heart formation

Cells display distinct metabolic characteristics depending on its differentiation stage. The fuel type of the cells serves not only as a source of energy but also as a driver of differentiation. Glucose, the primary nutrient to the cells, is a critical regulator of rapidly growing embryos. This metabolic change is a consequence as well as a cause of changes in genetic program. Disturbance of fetal glucose metabolism such as in diabetic pregnancy is associated with congenital heart disease. In utero hyperglycemia impacts the left-right axis establishment, migration of cardiac neural crest cells, conotruncal formation and mesenchymal formation of the cardiac cushion during early embryogenesis and causes cardiac hypertrophy in late fetal stages. In this review, we focus on the role of glucose in cardiogenesis and the molecular mechanisms underlying heart diseases associated with hyperglycemia.

Ovarian tissue damage after grafting: systematic review of strategies to improve follicle outcomes

Frozen-thawed human ovarian tissue endures large-scale follicle loss in the early post-grafting period, characterized by hypoxia lasting around 7 days. Tissue revascularization occurs progressively through new vessel invasion from the host and neoangiogenesis from the graft. Such reoxygenation kinetics lead to further potential damage caused by oxidative stress. The aim of the present manuscript is to provide a systematic review of proangiogenic growth factors, hormones and various antioxidants administered in the event of ovarian tissue transplantation to protect the follicle pool from depletion by boosting revascularization or decreasing oxidative stress. Although almost all investigated studies revealed an advantage in terms of revascularization and reduction in oxidative stress, far fewer demonstrated a positive impact on follicle survival. As the cascade of events driven by ischaemia after transplantation is a complex process involving numerous players, it appears that acting on specific molecular mechanisms, such as concentrations of proangiogenic growth factors, is not enough to significantly mitigate tissue damage. Strategies exploiting the activated tissue response to ischaemia for tissue healing and remodelling purposes, such as the use of antiapoptotic drugs and adult stem cells, are also discussed in the present review, since they yielded promising results in terms of follicle pool protection.

N-Acetylcysteine (NAC): Impacts on Human Health

N-acetylcysteine (NAC) is a medicine widely used to treat paracetamol overdose and as a mucolytic compound. It has a well-established safety profile, and its toxicity is uncommon and dependent on the route of administration and high dosages. Its remarkable antioxidant and anti-inflammatory capacity is the biochemical basis used to treat several diseases related to oxidative stress and inflammation. The primary role of NAC as an antioxidant stems from its ability to increase the intracellular concentration of glutathione (GSH), which is the most crucial biothiol responsible for cellular redox imbalance. As an anti-inflammatory compound, NAC can reduce levels of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6 and IL-1β) by suppressing the activity of nuclear factor kappa B (NF-κB). Despite NAC's relevant therapeutic potential, in several experimental studies, its effectiveness in clinical trials, addressing different pathological conditions, is still limited. Thus, the purpose of this chapter is to provide an overview of the medicinal effects and applications of NAC to human health based on current therapeutic evidence.

Difenoconazole induces cardiovascular toxicity through oxidative stress-mediated apoptosis in early life stages of zebrafish (Danio rerio)

Difenoconazole (DIF), a common broad-spectrum triazole fungicide, is associated with an increased risk of cardiovascular diseases. Unfortunately, little attention has been paid to the mechanisms underlying this association. In this study, zebrafish embryos were exposed to DIF (0, 0.3, 0.6 and 1.2 mg/L) from 4 to 96 h post fertilization (hpf) and cardiovascular toxicity was evaluated. Our results showed that DIF decreased hatching rate, survival rate and heart rate, with increased malformation rate. Cardiovascular deformities are the most prominent, including pericardial edema, abnormal cardiac structure and disrupted vascular pattern in two transgenic zebrafish models (myl7:egfp and fli1:egfp). DIF exacerbated oxidative stress by via accumulation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme. Cardiovascular apoptosis was triggered through increased expression of p53, bcl-2, bax and caspase 9, while DIF suppressed the transcription of key genes involved in calcium signaling and cardiac muscle contraction. These adverse outcomes were restored by the antioxidant N-acetyl-L-cysteine (NAC), indicating that oxidative stress played a crucial role in DIF-induced cardiovascular toxicity caused by apoptosis and inhibition of cardiac muscle contraction. Taken together, this study revealed the key role of oxidative stress in DIF-induced cardiovascular toxicity and provided novel insights into strategies to mitigate its toxicity.

The Incidence of Congenital Heart Defects in Offspring Among Women With Diabetes in Saudi Arabia

BACKGROUND

The risk of congenital anomalies is increased in infants of diabetic mothers (IDM). The most frequent cardiac anomalies in IDMs include ventricular septal defect, transposition of great arteries, and aortic stenosis.

OBJECTIVE

Estimating the incidence of infants with congenital heart defects (CHD) whose mothers have diabetes in Saudi Arabia at a tertiary hospital in the National Guard Health Affairs (NGHA) system.

MATERIALS AND METHODS

This study was a retrospective cohort. The population was all births of type 1 and type 2 diabetic mothers and non-diabetic mothers (also mothers with gestational diabetes) in NGHA by following the exclusion criteria, which were mothers over 40 and below 20 years of age, and other risk factors such as drug-induced congenital disease. The data was from deliveries from January 1st 2018 to January 1st 2019. Data were collected by chart review using the Best-Care system at NGHA hospital. Statistical Package for the Social Sciences (SPSS) version 20 (IBM Corp., Armonk, NY, USA) was used for the statistical analysis.

RESULTS

A total of 1838 diabetic mothers and non-exposure, non-diabetic mothers, with the outcome of whether the infant had CHD, were included in this study. Most of the mothers (544, 30.11%) were aged 30-34 years old. About two-thirds of mothers, 1161 (63.24%), weren't diabetic, 500 (27.23%) had gestational diabetes, 132 (7.19%) were type 2 diabetes (T2DM), and 43 (2.34%) were type 1 diabetes (T1DM). Two hundred eighteen (11.82%) offspring had CHD, and the remaining 1625 (88.17%) did not. The most frequent echocardiographic abnormalities in infants of diabetic mothers were patent ductus arteriosus (PDA) (31.75%), patent foramen ovale (PFO) (31.75%), and atrial septal defect (ASD) (23.64%).

CONCLUSION

The incidence of CHD among infants of included mothers in this cohort study was 11.82%. The most frequent echocardiographic abnormalities in the infants of diabetics were PDA and PFO. The incidence of CHD was higher among mothers who had T1DM followed by T2DM, and whose ages were between 30-34.

Mending a broken heart: In vitro, in vivo and in silico models of congenital heart disease

Birth defects contribute to ∼0.3% of global infant mortality in the first month of life, and congenital heart disease (CHD) is the most common birth defect among newborns worldwide. Despite the significant impact on human health, most treatments available for this heterogenous group of disorders are palliative at best. For this reason, the complex process of cardiogenesis, governed by multiple interlinked and dose-dependent pathways, is well investigated. Tissue, animal and, more recently, computerized models of the developing heart have facilitated important discoveries that are helping us to understand the genetic, epigenetic and mechanobiological contributors to CHD aetiology. In this Review, we discuss the strengths and limitations of different models of normal and abnormal cardiogenesis, ranging from single-cell systems and 3D cardiac organoids, to small and large animals and organ-level computational models. These investigative tools have revealed a diversity of pathogenic mechanisms that contribute to CHD, including genetic pathways, epigenetic regulators and shear wall stresses, paving the way for new strategies for screening and non-surgical treatment of CHD. As we discuss in this Review, one of the most-valuable advances in recent years has been the creation of highly personalized platforms with which to study individual diseases in clinically relevant settings.

Myocardium-Specific Deletion of Rac1 Causes Ventricular Noncompaction and Outflow Tract Defects

Background: Left ventricular noncompaction (LVNC) is a cardiomyopathy that can lead to arrhythmias, embolic events and heart failure. Despite our current knowledge of cardiac development, the mechanisms underlying noncompaction of the ventricular myocardium are still poorly understood. The small GTPase Rac1 acts as a crucial regulator of numerous developmental events. The present study aimed to investigate the cardiomyocyte specific role of Rac1 in embryonic heart development. Methods and Results: The Nkx2.5-Cre transgenic mice were crossed with Rac1^f/f mice to generate mice with a cardiomyocyte specific deletion of Rac1 (Rac1^Nkx2.5) during heart development. Embryonic Rac1^Nkx2.5 hearts at E12.5–E18.5 were collected for histological analysis. Overall, Rac1^Nkx2.5 hearts displayed a bifid apex, along with hypertrabeculation and a thin compact myocardium. Rac1^Nkx2.5 hearts also exhibited ventricular septal defects (VSDs) and double outlet right ventricle (DORV) or overriding aorta. Cardiomyocytes had a rounded morphology and were highly disorganized, and the myocardial expression of Scrib, a planar cell polarity protein, was reduced in Rac1^Nkx2.5 hearts. In addition, cell proliferation rate was significantly decreased in the Rac1^Nkx2.5 ventricular myocardium at E9.5. Conclusions: Rac1 deficiency in the myocardium impairs cardiomyocyte elongation and organization, and proliferative growth of the heart. A spectrum of CHDs arises in Rac1^Nkx2.5 hearts, implicating Rac1 signaling in the ventricular myocardium as a crucial regulator of OFT alignment, along with compact myocardium growth and development.

Elevated MST1 leads to apoptosis via depletion of YAP1 in cardiomyocytes exposed to high glucose

BACKGROUND

Gestational diabetes mellitus is a risk factor for congenital heart defects. The article aimed to investigate the expression and roles of MST1, YAP1, Last1/2 and Survivin in modulating HG-induced cardiomyocyte apoptosis and maternal diabetes-induced heart abnormality.

METHODS

Diabetes mellitus was induced in rats using streptozotocin. The protein expression and phosphorylation analysis in fetal heart tissue was assessed by western blot and immunohistochemical staining. Hoechst 33342 staining assay was performed to explore H9C2 apoptosis. The gene and protein expression in H9C2 cells was assessed by quantitative PCR and western blot. Knockdown of gene expression was assessed by RNA interference.

RESULTS

Our results revealed that increased MST1 protein levels in the heart tissues of the offspring of diabetic rats in vivo and in H9C2 cardiomyocytes under HG treatment in vitro, respectively. Knockdown and overexpression experiments showed that MST1 played a key role in mediating HG-induced apoptosis in cardiomyocytes. Downregulation of YAP1 was associated with HG-induced, MST1-mediated cardiomyocyte apoptosis. Further study showed that MST1 downregulated the protein level of YAP1 through mediation of YAP1 phosphorylation on Ser127 and Ser397; this process also required LATS1/2 participation. MST1 overexpression increased the phosphorylation levels of LATS1/2, which were also shown to be increased in the heart tissues of diabetic offspring. We also found that YAP1 mediated the expression of Survivin during HG-induced apoptosis, and the Survivin-inhibitor YM155 partially inhibited the role of YAP1 in suppressing apoptosis induced by HG in cardiomyocytes.

CONCLUSION

These findings reveal a regulatory mechanism of MST1/YAP1/Survivin signaling in modulating cardiomyocyte apoptosis in vitro and maternal diabetes-induced congenital heart defects in vivo.

N-acetylcysteine protects neonatal mice from ventricular hypertrophy induced by maternal obesity in a sex-specific manner

BACKGROUND

Maternal obesity induces adverse cardiac programming in offspring, and effective interventions are needed to prevent cardiovascular ill-health. Herein we hypothesized that exposure to maternal obesogenic diet-induced obesity in mice results in left ventricular remodelling and hypertrophy in early childhood, and that maternal N-acetylcysteine (NAC) treatment alleviates these effects in a sex-dependent manner.

METHODS AND RESULTS

The maternal obesity was induced in mice by the consumption of a Western diet accompanied by a 20 % sucrose solution. To determine the effect of NAC on the cardiac outcomes induced by maternal obesity, obese dams were continuously exposed to the obesogenic diet, with or without the oral NAC treatment during pregnancy. Left ventricular remodelling and hypertrophy occurred as early as 7 days after birth in the male offspring of obese dams (O-OB) compared with controls (O-CO). An over-expression of key genes and markers related to cardiac fibrosis accompanied by more disorganized myofibrils was observed in the hearts of neonatal male O-OB mice. When we next evaluated the level of oxidative stress in the hearts of neonatal mice, the activity of enzymatic antioxidants declined and expression of NOX enzyme complex was up-regulated in O-OB offspring hearts, but was normal in the offspring of NAC treated mice (O-OB/NAC). Maternal obesity also activated cardiac Akt and mammalian target of rapamycin (mTOR) signalling in offspring, and NAC treatment restored offspring cardiac Akt-mTOR signalling to normal irrespective of sex. NAC treatment did not prevent cardiomyocyte hypertrophy but did alleviate increased heart weight, interventricular septal thickness, and collagen content in male O-OB/NAC pups.

CONCLUSIONS

Collectively, our results indicated that NAC blunted cardiac fibrosis and related ventricular hypertrophy of male neonatal offspring in the setting of maternal obesity, potentially acting by reducing oxidative stress. The present study provides a basis for investigating the role of NAC in nutrition-related cardiac programming.

Development toxicity and cardiotoxicity in zebrafish from exposure to iprodione

Iprodione is a highly effective broad-spectrum fungicide commonly used for early disease control in fruit trees and vegetables. Pesticides often flow into watercourses due to rainfall, causing toxicity in non-target organisms, eventually entering the food chain. However, little information is available in the current literature about the toxicity of iprodione to cardiac development. The present study aimed to investigate the effect of iprodione on early embryonic development and its cardiotoxicity in aquatic animals, using zebrafish as a model. At 6-72 h post-fertilization (hpf), zebrafish were exposed to concentrations of 15 mg/L, 20 mg/L, and 25 mg/L (72 h-LC₅₀ = 21.15 mg/L). We found that exposure to iprodione resulted in yolk edema, increased mortality, and shortened body length in zebrafish embryos. In addition, iprodione was also found to induce edema in the pericardium of zebrafish, decrease heart rate, and cause the failure of cardiac cyclization. Exposure to iprodione significantly increased the accumulation of ROS and altered the activity of antioxidant enzymes (MDA, CAT) in zebrafish embryos. Moreover, iprodione induced changes in the transcription levels of heart developmental-related genes and apoptosis-related genes. In addition, Astaxanthin (antioxidant) can partially rescue the toxic phenotype caused by iprodione. Apoptosis-related genes and heart developmental-related genes were rescued after astaxanazin treatment. The results suggest that iprodione induces developmental and cardiac toxicity in zebrafish embryos, which provides new evidence of the toxicity of iprodione to organisms in aquatic ecosystems and assessing human health risks.

[Association of maternal diabetes mellitus and UCP2 gene polymorphisms with congenital heart disease in offspring: a case-control study]

OBJECTIVE

To study the association of maternal diabetes mellitus (DM), uncoupling protein 2 (UCP2) gene polymorphisms, and their interaction with the risk of congenital heart disease (CHD) in offspring.

METHODS

A hospital-based case-control study was conducted. A total of 464 mothers of children with CHD alone who were diagnosed in Hunan Children's Hospital from March 2018 to August 2019 were enrolled as the case group. A total of 504 mothers of healthy children who were hospitalized during the same period and did not have any deformity were enrolled as the control group. A questionnaire survey was performed to collect the information on exposure. Venous blood samples (5 mL) were collected from the mothers to detect UCP2 gene polymorphisms. A multivariate logistic regression analysis was used to investigate the association of maternal DM, UCP2 gene polymorphisms, and their interaction with CHD in offspring.

RESULTS

After control for confounding factors, the multivariate logistic regression analysis showed that mothers with gestational DM (OR=2.96, 95%CI: 1.57-5.59), a history of gestational DM (OR=3.16, 95%CI: 1.59-6.28), and pregestational DM (OR=4.52, 95%CI: 2.41-8.50) significantly increased the risk of CHD in offspring (P<0.05). The polymorphisms of the UCP2 gene at rs659366 (T/C vs C/C: OR=1.49, 95%CI: 1.02-2.16; T/T vs C/C: OR=2.77, 95%CI: 1.67-4.62) and rs660339 (A/A vs G/G: OR=2.19, 95%CI: 1.34-3.58) were significantly associated with risk of CHD in offspring (P<0.05). The interaction analysis showed an interaction between the polymorphisms of the UCP2 gene at rs659366 and rs660339 and maternal DM in the development of CHD (P<0.05).

CONCLUSIONS

Maternal DM, UCP2 gene polymorphisms, and their interaction are associated with the development of CHD in offspring.

Downregulation of SOX11 in fetal heart tissue, under hyperglycemic environment, mediates cardiomyocytes apoptosis

Gestational diabetes mellitus is one of the causes of abnormal embryonic heart development, but the mechanism is still poor. This study investigated the regulatory mechanism and role of SOX11 in congenital heart abnormality in a hyperglycemic environment. Immunohistochemistry, Western blotting, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) showed decreased SOX11 protein and messenger RNA (mRNA) levels in the heart tissue of diabetic offspring compared with the control group. A Sequenom EpiTYPER MassArray showed that methylation sites upstream in SOX11 region 1 were increased in the diabetic group compared with the control group. Luciferase reporter assays and qRT-PCR showed that Dnmt3b overexpression decreased SOX11 promoter activity and its mRNA level, whereas Dnmt3a had little effect on regulating SOX11 expression. Furthermore, we found that Dnmt3L cooperated with Dnmt3b to regulate SOX11 gene expression. Additionally, the function of SOX11 silencing was analyzed by using small interfering RNA-mediated knockdown. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and apoptotic assays showed that SOX11 downregulation inhibited cell viability and induced apoptosis in cardiomyocytes. Overexpression of the SOX11 gene suppressed cardiomyocytes apoptosis after high glucose treatment. We identified a novel epigenetic regulatory mechanism of SOX11 during heart development in a hyperglycemic environment and revealed a distinct role of SOX11 in mediating cardiomyocytes viability and apoptosis.

Exposure to pyrimethanil induces developmental toxicity and cardiotoxicity in zebrafish

Pyrimethanil is a broad-spectrum fungicide commonly used in the prevention and treatment of Botrytis cinerea. However, little information is available in the literature to show the toxicity of Pyrimethanil to cardiac development. In this study, we used an experimental animal model to explore the developmental and cardiac toxicity of Pyrimethanil in aquatic vertebrates; we exposed zebrafish embryos to Pyrimethanil at concentrations of 2, 4, and 6 mg/L from 5.5 to 72 h post fertilisation. We found that Pyrimethanil caused a decrease in the hatching rate, heart rate, and survival rate of zebrafish embryos. Pyrimethanil exposure also resulted in pericardial and yolk sac edema, spinal deformity, and heart loop failure. Moreover, Pyrimethanil increased reactive oxygen stress levels and heightened the activity of superoxide dismutase and catalase. Alterations were induced in the transcription of apoptosis-related genes (p53, Bax, Bcl2, Casp 9, and Casp6l1) and heart development-related genes (Tbx2b, Gata4, Myh6, Vmhc, Nppa, Bmp2b, Bpm 4, and Bpm 10). Our data showed that the activation of Wnt signalling by BML-284 could partially rescue the malformed phenotype caused by Pyrimethanil. Our results provide new evidence for Pyrimethanil's toxicity and the danger of its residues in the environment and agricultural products.

Prenatal Amino Acid Supplementation to Improve Fetal Growth: A Systematic Review and Meta-Analysis

Aberrant fetal growth remains a leading cause of perinatal morbidity and mortality and is associated with a risk of developing non-communicable diseases later in life. We performed a systematic review and meta-analysis combining human and animal studies to assess whether prenatal amino acid (AA) supplementation could be a promising approach to promote healthy fetal growth. PubMed, Embase, and Cochrane libraries were searched to identify studies orally supplementing the following AA groups during gestation: (1) arginine family, (2) branched chain (BCAA), and (3) methyl donors. The primary outcome was fetal/birth weight. Twenty-two human and 89 animal studies were included in the systematic review. The arginine family and, especially, arginine itself were studied the most. Our meta-analysis showed beneficial effects of arginine and (N-Carbamyl) glutamate (NCG) but not aspartic acid and citrulline on fetal/birth weight. However, no effects were reported when an isonitrogenous control diet was included. BCAA and methyl donor supplementation did not affect fetal/birth weight. Arginine family supplementation, in particular arginine and NCG, improves fetal growth in complicated pregnancies. BCAA and methyl donor supplementation do not seem to be as promising in targeting fetal growth. Well-controlled research in complicated pregnancies is needed before ruling out AA supplements or preferring arginine above other AAs.

NOX2 Is Critical to Endocardial to Mesenchymal Transition and Heart Development

NADPH oxidases (NOX) are a major source of reactive oxygen species (ROS) production in the heart. ROS signaling regulates gene expression, cell proliferation, apoptosis, and migration. However, the role of NOX2 in embryonic heart development remains elusive. We hypothesized that deficiency of Nox2 disrupts endocardial to mesenchymal transition (EndMT) and results in congenital septal and valvular defects. Our data show that 34% of Nox2^−/− neonatal mice had various congenital heart defects (CHDs) including atrial septal defects (ASD), ventricular septal defects (VSD), atrioventricular canal defects (AVCD), and malformation of atrioventricular and aortic valves. Notably, Nox2^−/− embryonic hearts show abnormal development of the endocardial cushion as evidenced by decreased cell proliferation and an increased rate of apoptosis. Additionally, Nox2 deficiency disrupted EndMT of atrioventricular cushion explants ex vivo. Furthermore, treatment with N-acetylcysteine (NAC) to reduce ROS levels in the wild-type endocardial cushion explants decreased the number of cells undergoing EndMT. Importantly, deficiency of Nox2 was associated with reduced expression of Gata4, Tgfβ2, Bmp2, Bmp4, and Snail1, which are critical to endocardial cushion and valvoseptal development. We conclude that NOX2 is critical to EndMT, endocardial cushion cell proliferation, and normal embryonic heart development.

AHR-mediated ROS production contributes to the cardiac developmental toxicity of PM2.5 in zebrafish embryos

Recent studies have shown an association between maternal exposure to ambient fine particle matter (PM2.5) and congenital heart defects in the offspring, but the underlying molecular mechanisms are yet to be elucidated. Previously, we demonstrated that extractable organic matter (EOM) from PM2.5 induced heart defects in zebrafish embryos by activating the aromatic hydrocarbon receptor (AHR). Hence, we hypothesized that AHR mediates excessive reactive oxygen species (ROS) production, leading to the cardiac developmental toxicity of PM2.5. To test our hypothesis, we examined AHR activity and ROS levels in the heart of zebrafish embryos under a fluorescence microscope. mRNA expression levels were then quantified using qPCR whereas DNA damage and apoptosis were detected by immunofluorescence. Our results showed that the AHR inhibitor, CH223191 (CH) as well as the ROS scavenger, N-Acetyl-L-cysteine (NAC), significantly mitigated the PM2.5-induced cardiac malformations in zebrafish embryos. Furthermore, both CH and NAC diminished the EOM-elevated ROS generation, DNA damage and apoptosis in the test system. Incidentally, both CH and NAC attenuated the EOM-induced changes in the mRNA expression of genes involved in cardiac development (nkx2.5, sox9b), oxidative stress (nrf2a, nrf2b, gstp1, gstp2, sod2, ho1, cat) and apoptosis (p53, bax). We further confirmed that AHR activity is a necessary condition for EOM-induced ROS generation, DNA damage and apoptosis, through AHR knockdown. However, the ROS scavenger NAC did not counteract the EOM-induced AHR activity. In conclusion, our findings suggest that AHR mediates EOM-induced oxidative stress, resulting in DNA damage and apoptosis, thereby contributing to the cardiac developmental toxicity of PM2.5.

Pregestational diabetes in pregnancy: Complications, management, surveillance, and mechanisms of disease-A review

Diabetes is an increasingly common diagnosis among pregnant women. Pregestational diabetes is associated with an increase in many adverse pregnancy outcomes, which impact both on the woman and her fetus. The models of pregnancy care for women with diabetes are based largely on observational data or consensus opinion. Strategies for aneuploidy screening and monitoring for fetal well-being should be modified in women with diabetes. There is an increasing understanding of the mechanisms by which congenital anomalies and disorders of fetal growth occur, involving epigenetic modifications, changes in gene expression in critical developmental pathways, and oxidative stress. This knowledge may lead to pathways for improved care for these high-risk pregnancies.

Sapropterin reduces coronary artery malformation in offspring of pregestational diabetes mice

Endothelial nitric oxide synthase (eNOS) and oxidative stress are critical to embryonic coronary artery development. Maternal diabetes increases oxidative stress and reduces eNOS activity in the fetal heart. Sapropterin (Kuvan®) is an orally active, synthetic form of tetrahydrobiopterin (BH4) and a co-factor for eNOS with antioxidant properties. The aim of the present study was to examine the effects of sapropterin on fetal coronary artery development during pregestational diabetes in mice. Diabetes was induced by streptozotocin to adult female C57BL/6 mice. Sapropterin (10 mg/kg/day) was orally administered to pregnant mice from E0.5 to E18.5. Fetal hearts were collected at E18.5 for coronary artery morphological analysis. Sapropterin treatment to diabetic dams reduced the incidence of coronary artery malformation in offspring from 50.0% to 20.6%. Decreases in coronary artery luminal diameter, volume and abundance in fetal hearts from diabetic mothers, were prevented by sapropterin treatment. Maternal diabetes reduced epicardial epithelial-to-mesenchymal transition (EMT) and expression of transcription and growth factors critical to coronary artery development including hypoxia-inducible factor 1a (Hif1a), Snail1, Slug, β-catenin, retinaldehyde dehydrogenase 2 (Aldh1a2), basic fibroblast growth factor (bFGF) and vascular endothelial group factor receptor 2 (Vegfr2) in E12.5 hearts. Additionally, eNOS phosphorylation was lower while oxidative stress was higher in E12.5 hearts from maternal diabetes. Notably, these abnormalities were all restored to normal levels after sapropterin treatment. In conclusion, sapropterin treatment increases eNOS activity, lowers oxidative stress and reduces coronary artery malformation in offspring of pregestational diabetes. Sapropterin may have therapeutic potential in preventing coronary artery malformation in maternal diabetes.

Maternal diabetes during pregnancy and early onset of cardiovascular disease in offspring: population based cohort study with 40 years of follow-up

OBJECTIVE

To evaluate the associations between maternal diabetes diagnosed before or during pregnancy and early onset cardiovascular disease (CVD) in offspring during their first four decades of life.

DESIGN

Population based cohort study.

SETTING

Danish national health registries.

PARTICIPANTS

All 2 432 000 liveborn children without congenital heart disease in Denmark during 1977-2016. Follow-up began at birth and continued until first time diagnosis of CVD, death, emigration, or 31 December 2016, whichever came first.

EXPOSURES FOR OBSERVATIONAL STUDIES

Pregestational diabetes, including type 1 diabetes (n=22 055) and type 2 diabetes (n=6537), and gestational diabetes (n=26 272).

MAIN OUTCOME MEASURES

The primary outcome was early onset CVD (excluding congenital heart diseases) defined by hospital diagnosis. Associations between maternal diabetes and risks of early onset CVD in offspring were studied. Cox regression was used to assess whether a maternal history of CVD or maternal diabetic complications affected these associations. Adjustments were made for calendar year, sex, singleton status, maternal factors (parity, age, smoking, education, cohabitation, residence at childbirth, history of CVD before childbirth), and paternal history of CVD before childbirth. The cumulative incidence was averaged across all individuals, and factors were adjusted while treating deaths from causes other than CVD as competing events.

RESULTS

During up to 40 years of follow-up, 1153 offspring of mothers with diabetes and 91 311 offspring of mothers who did not have diabetes were diagnosed with CVD. Offspring of mothers with diabetes had a 29% increased overall rate of early onset CVD (hazard ratio 1.29 (95% confidence interval 1.21 to 1.37); cumulative incidence among offspring unexposed to maternal diabetes at 40 years of age 13.07% (12.92% to 13.21%), difference in cumulative incidence between exposed and unexposed offspring 4.72% (2.37% to 7.06%)). The sibship design yielded results similar to those of the unpaired design based on the whole cohort. Both pregestational diabetes (1.34 (1.25 to 1.43)) and gestational diabetes (1.19 (1.07 to 1.32)) were associated with increased rates of CVD in offspring. We also observed varied increased rates of specific early onset CVDs, particularly heart failure (1.45 (0.89 to 2.35)), hypertensive disease (1.78 (1.50 to 2.11)), deep vein thrombosis (1.82 (1.38 to 2.41)), and pulmonary embolism (1.91 (1.31 to 2.80)). Increased rates of CVD were seen in different age groups from childhood to early adulthood until age 40 years. The increased rates were more pronounced among offspring of mothers with diabetic complications (1.60 (1.25 to 2.05)). A higher incidence of early onset CVD in offspring of mothers with diabetes and comorbid CVD (1.73 (1.36 to 2.20)) was associated with the added influence of comorbid CVD but not due to the interaction between diabetes and CVD on the multiplicative scale (P value for interaction 0.94).

CONCLUSIONS

Children of mothers with diabetes, especially those mothers with a history of CVD or diabetic complications, have increased rates of early onset CVD from childhood to early adulthood. If maternal diabetes does have a causal association with increased CVD rate in offspring, the prevention, screening, and treatment of diabetes in women of childbearing age could help to reduce the risk of CVD in the next generation.

Say NO to ROS: Their Roles in Embryonic Heart Development and Pathogenesis of Congenital Heart Defects in Maternal Diabetes

Congenital heart defects (CHDs) are the most prevalent and serious birth defect, occurring in 1% of all live births. Pregestational maternal diabetes is a known risk factor for the development of CHDs, elevating the risk in the child by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. In experimental animal models of pregestational diabetes induced-CHDs, upwards of 50% of offspring display congenital malformations of the heart, including septal, valvular, and outflow tract defects. Specifically, the imbalance of nitric oxide (NO) and reactive oxygen species (ROS) signaling is a major driver of the development of CHDs in offspring of mice with pregestational diabetes. NO from endothelial nitric oxide synthase (eNOS) is crucial to cardiogenesis, regulating various cellular and molecular processes. In fact, deficiency in eNOS results in CHDs and coronary artery malformation. Embryonic hearts from diabetic dams exhibit eNOS uncoupling and oxidative stress. Maternal treatment with sapropterin, a cofactor of eNOS, and antioxidants such as N-acetylcysteine, vitamin E, and glutathione as well as maternal exercise have been shown to improve eNOS function, reduce oxidative stress, and lower the incidence CHDs in the offspring of mice with pregestational diabetes. This review summarizes recent data on pregestational diabetes-induced CHDs, and offers insights into the important roles of NO and ROS in embryonic heart development and pathogenesis of CHDs in maternal diabetes.

Maternal hyperglycemia and fetal cardiac development: Clinical impact and underlying mechanisms

Congenital heart disease (CHD) is the most common type of birth defect and is both a significant pediatric and adult health problem, in light of a growing population of survivors. The etiology of CHD has been considered to be multifactorial with genetic and environmental factors playing important roles. The combination of advances in cardiac developmental biology, which have resulted in the elucidation of molecular pathways regulating normal cardiac morphogenesis, and genome sequencing technology have allowed the discovery of numerous genetic contributors of CHD ranging from chromosomal abnormalities to single gene variants. Conversely, mechanistic details of the contribution of environmental factors to CHD remain unknown. Maternal diabetes mellitus (matDM) is a well-established and increasingly prevalent environmental risk factor for CHD, but the underlying etiologic mechanisms by which pregestational matDM increases the vulnerability of embryos to cardiac malformations remains largely elusive. Here, we will briefly discuss the multifactorial etiology of CHD with a focus on the epidemiologic link between matDM and CHD. We will describe the animal models used to study the underlying mechanisms between matDM and CHD and review the numerous cellular and molecular pathways affected by maternal hyperglycemia in the developing heart. Last, we discuss how this increased understanding may open the door for the development of novel prevention strategies to reduce the incidence of CHD in this high-risk population.