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.

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First report of polymorphisms in MTRR, GATA4, VEGF, and ISL1 genes in Pakistani children with isolated ventricular septal defects (VSD)

Italian Journal of Pediatrics ◽

10.1186/s13052-021-01022-7 ◽

2021 ◽

Vol 47 (1) ◽

Author(s):

Sumbal Sarwar ◽

Farah Ehsan ◽

Shabana ◽

Amna Tahir ◽

Mahrukh Jamil ◽

...

Keyword(s):

Heart Development ◽

Heart Defects ◽

Demographic Data ◽

Gene Variant ◽

Nucleotide Polymorphisms ◽

Ventricular Septal Defects ◽

First Report ◽

Number Of Children ◽

Septal Defects ◽

Genotype Frequencies

Abstract Background Ventricular septal defects (VSDs) are malformations in the septum separating the heart’s ventricles. VSDs may present as a single anomaly (isolated/nonsyndromic VSD) or as part of a group of phenotypes (syndromic VSD). The exact location of the defect is crucial in linking the defect to the underlying genetic cause. The number of children visiting cardiac surgery units is constantly increasing. However, there are no representative data available on the genetics of VSDs in Pakistani children. Methods Two hundred forty-two subjects (121 VSD children and 121 healthy controls) were recruited from pediatric cardiac units of Lahore. The clinical and demographic data of the subjects were collected. A total of four SNPs, one each from MTRR, GATA4, VEGF, and ISL1 genes were genotyped by PCR-RFLP. Results The results showed that the minor allele (T) frequency (MAFs) for the MTRR gene variant rs1532268 (c.524C > T) was 0.20 and 0.41 in the controls and the cases, respectively, with the genotype frequencies 3, 35, 62% in the controls and 12, 59 and 29% in the cases for TT, CT, CC genotypes, respectively (allelic OR: 5.73, CI: 3.82–8.61, p-value: 5.11 × 10− 7). For the GATA4 variant rs104894073 (c.886G > A), the MAF for the controls and the cases was 0.16 and 0.37, respectively, the frequencies of AA, GA and GG genotypes were 2, 28, and 70% in the controls and 5, 64 and 31% of the cases (allelic OR: 3.08, CI: 2.00–4.74, p-value: 8.36 × 10− 8). The rs699947 (c.-2578C > A) of VEGF gene showed MAF 0.36 and 0.53 for the controls and cases, respectively, with the genotype frequencies 13, 42, and 45% in the controls and 22, 15, and 63% in the cases for the AA, CA, CC (allelic OR: 2.03, CI: 1.41–2.92, p-value: 0.0001). The ISL1 gene variant rs6867206 (g.51356860 T > C), the MAFs were 0.26 and 0.31 in the controls and cases, respectively. The genotype frequencies were 48, 52, 0% in the controls and 39, 61, 0% in the cases for TT, TC, CC genotypes (allelic OR: 0.27, CI: 0.85–1.89, p-value: 0.227). The MTRR, GATA4 and VEGF variants showed association while ISL1 variant did not appear to be associated with the VSD in the recruited cohort. Conclusion This first report in Pakistani children demonstrates that single nucleotide polymorphisms in genes encoding transcription factors, signaling molecules and structural heart genes involved in fetal heart development are associated with developmental heart defects., however further work is needed to validate the results of the current investigation.

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Epigenetic Regulation of Cardiac Neural Crest Cells

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.678954 ◽

2021 ◽

Vol 9 ◽

Author(s):

Shun Yan ◽

Jin Lu ◽

Kai Jiao

Keyword(s):

Neural Crest ◽

Epigenetic Regulation ◽

Heart Development ◽

Congenital Heart ◽

Heart Diseases ◽

Heart Defects ◽

Neural Crest Cells ◽

Abnormal Development ◽

Cardiac Neural Crest ◽

Epigenetic Regulators

The cardiac neural crest cells (cNCCs) is a transient, migratory cell population that contribute to the formation of major arteries and the septa and valves of the heart. Abnormal development of cNCCs leads to a spectrum of congenital heart defects that mainly affect the outflow region of the hearts. Signaling molecules and transcription factors are the best studied regulatory events controlling cNCC development. In recent years, however, accumulated evidence supports that epigenetic regulation also plays an important role in cNCC development. Here, we summarize the functions of epigenetic regulators during cNCC development as well as cNCC related cardiovascular defects. These factors include ATP-dependent chromatin remodeling factors, histone modifiers and DNA methylation modulators. In many cases, mutations in the genes encoding these factors are known to cause inborn heart diseases. A better understanding of epigenetic regulators, their activities and their roles during heart development will ultimately contribute to the development of new clinical applications for patients with congenital heart disease.

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

Antioxidants ◽

10.3390/antiox8100436 ◽

2019 ◽

Vol 8 (10) ◽

pp. 436 ◽

Cited By ~ 5

Author(s):

Engineer ◽

Saiyin ◽

Greco ◽

Feng

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Congenital Heart Defects ◽

Heart Development ◽

Congenital Heart ◽

Heart Defects ◽

Maternal Diabetes ◽

Embryonic Heart ◽

Pregestational Diabetes ◽

Enos Uncoupling

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.

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Leptin affects endocardial cushion formation by modulating EMT and migration via Akt signaling cascades

The Journal of Cell Biology ◽

10.1083/jcb.200708197 ◽

2008 ◽

Vol 181 (2) ◽

pp. 367-380 ◽

Cited By ~ 18

Author(s):

Anjali K. Nath ◽

Rachel M. Brown ◽

Michael Michaud ◽

M. Rocio Sierra-Honigmann ◽

Michael Snyder ◽

...

Keyword(s):

Signaling Pathway ◽

Ex Vivo ◽

Heart Defects ◽

Metastatic Cancer ◽

Akt Signaling ◽

Central Feature ◽

Αvβ3 Integrin ◽

Ex Vivo Model ◽

Mesenchymal Transition ◽

And Migration

Blood circulation is dependent on heart valves to direct blood flow through the heart and great vessels. Valve development relies on epithelial to mesenchymal transition (EMT), a central feature of embryonic development and metastatic cancer. Abnormal EMT and remodeling contribute to the etiology of several congenital heart defects. Leptin and its receptor were detected in the mouse embryonic heart. Using an ex vivo model of cardiac EMT, the inhibition of leptin results in a signal transducer and activator of transcription 3 and Snail/vascular endothelial cadherin–independent decrease in EMT and migration. Our data suggest that an Akt signaling pathway underlies the observed phenotype. Furthermore, loss of leptin phenocopied the functional inhibition of αvβ3 integrin receptor and resulted in decreased αvβ3 integrin and matrix metalloprotease 2, suggesting that the leptin signaling pathway is involved in adhesion and migration processes. This study adds leptin to the repertoire of factors that mediate EMT and, for the first time, demonstrates a role for the interleukin 6 family in embryonic EMT.

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Zyxin Mediates Actin Fiber Reorganization in Epithelial–Mesenchymal Transition and Contributes to Endocardial Morphogenesis

Molecular Biology of the Cell ◽

10.1091/mbc.e09-01-0046 ◽

2009 ◽

Vol 20 (13) ◽

pp. 3115-3124 ◽

Cited By ~ 40

Author(s):

Masaki Mori ◽

Hironori Nakagami ◽

Nobutaka Koibuchi ◽

Koichi Miura ◽

Yoichi Takami ◽

...

Keyword(s):

Cell Motility ◽

Heart Development ◽

Cancer Metastasis ◽

Epithelial Mesenchymal Transition ◽

Focal Adhesions ◽

Atrioventricular Canal ◽

Actin Reorganization ◽

Mesenchymal Transition ◽

Actin Fiber ◽

Tgf Β1

Epithelial–mesenchymal transition (EMT) confers destabilization of cell–cell adhesion and cell motility required for morphogenesis or cancer metastasis. Here we report that zyxin, a focal adhesion-associated LIM protein, is essential for actin reorganization for cell migration in TGF-β1–induced EMT in normal murine mammary gland (NMuMG) cells. TGF-β1 induced the relocation of zyxin from focal adhesions to actin fibers. In addition, TGF-β1 up-regulated zyxin via a transcription factor, Twist1. Depletion of either zyxin or Twist1 abrogated the TGF-β1–dependent EMT, including enhanced cell motility and actin reorganization, indicating the TGF-β1-Twist1-zyxin signal for EMT. Both zyxin and Twist1 were predominantly expressed in the cardiac atrioventricular canal (AVC) that undergoes EMT during heart development. We further performed ex vivo AVC explant assay and revealed that zyxin was required for the reorganization of actin fibers and migration of the endocardial cells. Thus, zyxin reorganizes actin fibers and enhances cell motility in response to TGF-β1, thereby regulating EMT.

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Semaphorin3f as an intrinsic regulator of chamber-specific heart development

10.1101/2021.05.19.444704 ◽

2021 ◽

Author(s):

Rami Halabi ◽

Paula B. Cechmanek ◽

Carrie L. Hehr ◽

Sarah McFarlane

Keyword(s):

Congenital Heart Defects ◽

Heart Development ◽

Congenital Heart ◽

Molecular Mechanisms ◽

Heart Defects ◽

Border Region ◽

Specific Gene ◽

Atrioventricular Canal ◽

Term Survival ◽

Ventricular Cardiomyocytes

During development a pool of precursors form a heart with atrial and ventricular chambers that exhibit distinct transcriptional and electrophysiological properties. Normal development of these chambers is essential for full term survival of the fetus, and deviations result in congenital heart defects. The large number of genes that may cause congenital heart defects when mutated, and the genetic variability and penetrance of the ensuing phenotypes, reveals a need to understand the molecular mechanisms that allow for the formation of chamber-specific cardiomyocyte differentiation. We find that in the developing zebrafish heart, mRNA for a secreted Semaphorin (Sema), Sema3fb, is expressed by all cardiomyocytes, whereas mRNA for its receptor Plexina3 (Plxna3) is expressed by ventricular cardiomyocytes. In sema3fb CRISPR zebrafish mutants, ventricular chamber development is impaired; the ventricles of mutants are smaller in size than their wild type siblings, apparently because of differences in cell size and not cell numbers, with ventricular cardiomyocytes failing to undergo normal developmental hypertrophy. Analysis of chamber differentiation indicates defects in chamber specific gene expression at the border between the ventricular and atrial chambers, with spillage of ventricular chamber genes into the atrium, and vice versa, and a failure to restrict bmp4a mRNA to the atrioventricular canal. The disrupted atrioventricular border region in mutants is accompanied by hypoplastic heart chambers and impaired cardiac function. These data suggest a model whereby cardiomyocytes secrete a Sema cue that, through spatially restricted expression of the receptor, signals in a ventricular chamber-specific manner to establish a distinct border between atrial and ventricular chambers that is important for functional development of the heart.

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Congenital Heart Disease in Down Syndrome

Pediatrics in Review ◽

10.1542/pir.14.12.488 ◽

1993 ◽

Vol 14 (12) ◽

pp. 488-494

Keyword(s):

Congenital Heart Disease ◽

Down Syndrome ◽

Heart Disease ◽

Congenital Heart ◽

Chromosomal Abnormalities ◽

Heart Defects ◽

Endocardial Cushion ◽

Ventricular Septal Defects ◽

Septal Defects ◽

Endocardial Cushion Defect

Trisomy 21, Down syndrome, is one of a number of chromosomal abnormalities associated with congenital heart disease. Recent studies indicate that approximately 5% of all congenital heart defects are associated with some form of chromosomal abnormality, the majority of which are Down syndrome. Reports of the incidence of congenital heart disease in patients who have Down syndrome have varied, but it is commonly accepted to be 50%. Endocardial cushion defect and ventricular septal defects both have been reported as the "most common," but the majority of investigators accept the endocardial cushion defect as being the more frequent. The association between endocardial cushion defects and Down syndrome is so striking that when an endocardial cushion defect is diagnosed in an infant, the possibility of Down syndrome always should be considered.

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A novel role for VEGF in endocardial cushion formation and its potential contribution to congenital heart defects

Development ◽

10.1242/dev.128.9.1531 ◽

2001 ◽

Vol 128 (9) ◽

pp. 1531-1538 ◽

Cited By ~ 5

Author(s):

Y. Dor ◽

T.D. Camenisch ◽

A. Itin ◽

G.I. Fishman ◽

J.A. McDonald ◽

...

Keyword(s):

Growth Factor ◽

Heart Development ◽

Heart Defects ◽

Negative Regulator ◽

Congenital Defects ◽

Endocardial Cushion ◽

Potential Contribution ◽

Vegf Receptor ◽

Endocardial Cushions ◽

Mesenchymal Transformation

Normal cardiovascular development is exquisitely dependent on the correct dosage of the angiogenic growth factor and vascular morphogen vascular endothelial growth factor (VEGF). However, cardiac expression of VEGF is also robustly augmented during hypoxic insults, potentially mediating the well-established teratogenic effects of hypoxia on heart development. We report that during normal heart morphogenesis VEGF is specifically upregulated in the atrioventricular (AV) field of the heart tube soon after the onset of endocardial cushion formation (i.e. the endocardium-derived structures that build the heart septa and valves). To model hypoxia-dependent induction of VEGF in vivo, we conditionally induced VEGF expression in the myocardium using a tetracycline-regulated transgenic system. Premature induction of myocardial VEGF in E9.5 embryos to levels comparable with those induced by hypoxia prevented formation of endocardial cushions. When added to explanted embryonic AV tissue, VEGF fully inhibited endocardial-to-mesenchymal transformation. Transformation was also abrogated in AV explants subjected to experimental hypoxia but fully restored in the presence of an inhibitory soluble VEGF receptor 1 chimeric protein. Together, these results suggest a novel developmental role for VEGF as a negative regulator of endocardial-to-mesenchymal transformation that underlies the formation of endocardial cushions. Moreover, ischemia-induced VEGF may be the molecular link between hypoxia and congenital defects in heart septation.

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Abstract 18055: Induced Growth of Hypoplastic Cardiac Structures to Facilitate Repair of Congenital Defects

Circulation ◽

10.1161/circ.132.suppl_3.18055 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Daniel F Labuz ◽

Lee A Pyles ◽

James A Berry ◽

John E Foker

Keyword(s):

Heart Defects ◽

Pulmonary Atresia ◽

Coarctation Of The Aorta ◽

Congenital Defects ◽

Atrioventricular Canal ◽

Septal Defects ◽

Flow Through ◽

Catch Up ◽

Growth Induction

Introduction: Congenital heart defects (CHD) may include hypoplastic valves, ventricles and vessels which complicate repairs. Our hypotheses were that hypoplastic structures are developmental rather than primarily genetic in origin and the correct biomechanical signal would induce catch up growth. Our corollary hypothesis was that the growth signal is provided by flow, not pressure. First stage operations, therefore, were designed to increase flow and induce growth. Once growth was sufficient, a second operation would often complete the repair. We report our results using flow induced growth of hypoplastic structures to facilitate repair in 3 types of CHD. Methods: Three groups of CHD patients with associated hypoplastic structures: unbalanced atrioventricular canal defects (UAVC); pulmonary atresia with intact ventricular septum (PAIVS); and coarctation of the aorta (CoA) were reviewed. Operations increased flow through the hypoplastic structures, such as creating restrictive septal defects to increase flow through the hypoplastic AV valves and ventricles (UAVC, PAIVS) or relieving obstruction (CoA) to enhance aortic valve and arch flow. Results: On follow up, virtually all (85/90) hypoplastic structures reached normal size and the rest had nearly comparable growth (Table). Conclusions: 1) Operations designed to increase flow through hypoplastic structures reliably induced catch up growth of UAVC, PAIVS and CoA lesions. 2) The growth response supported underdevelopment as the cause of hypoplasia and flow as the growth signal to reverse it. 3) Growth induction allowed two ventricle repairs in UAVC and PAIVS patients and avoided extended arch repairs in CoA; all with decreased operative risk. 4) Following catch up growth of the hypoplastic lesions, the outlook improved to that of patients with balanced AVCs, normal sized RVs in pulmonary atresia and well repaired CoA. 5) Once normal size was reached growth continued, producing a durable result.

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Relationship of birth weight with congenital cardiovascular malformations in a population-based study

Cardiology in the Young ◽

10.1017/s1047951114001644 ◽

2014 ◽

Vol 25 (6) ◽

pp. 1086-1092 ◽

Cited By ~ 7

Author(s):

Robert A. Petrossian ◽

Karen S. Kuehl ◽

Christopher A. Loffredo

Keyword(s):

Down Syndrome ◽

Birth Weight ◽

Heart Defects ◽

Population Based ◽

Endocardial Cushion ◽

Left Heart ◽

Cardiovascular Malformations ◽

Ventricular Septal Defects ◽

Conotruncal Heart Defects ◽

Septal Defects

AbstractIntroduction: A known comorbidity of congenital cardiovascular malformations is low birth weight, but the reasons for this association remain obscure. This retrospective study examines the relationship between congenital cardiovascular malformations and the birth weight of singletons, taking into account differences in gestational age and other factors. Methods: Using data from the retrospective, population-based Baltimore–Washington Infant Study, six types of congenital cardiovascular malformations were investigated in comparison with controls (n=3519) through linear regression: d-transposition of the great arteries (n=187), other conotruncal heart defects (n=361), endocardial cushion defects (n=281), left heart obstructive lesions (n=507), atrial septal defects (n=281), and membranous ventricular septal defects (n=622). Results: Infants with conotruncal heart defects (−218 g), endocardial cushion defects with Down syndrome (−265 g), endocardial cushion defects without Down syndrome (−194 g), left heart obstructive lesions (−143 g), atrial septal defects (−150 g), and membranous ventricular septal defects (−127 g) showed significant birth weight deficits, adjusting for gestational age, and other covariates. Infants with d-transposition of the great arteries (−67 g) did not show significant birth weight deficits compared with the control group. Discussion: The degree of birth weight decrement appears to be highly related to the specific type of congenital cardiovascular malformation. As a whole, these infants do not exhibit low birth weights solely because of being premature, and thus other mechanisms must underlie these associations.

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