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1.
Am J Hum Genet ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39332409

RESUMO

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly often accompanied by other structural anomalies and/or neurobehavioral manifestations. Rare de novo protein-coding variants and copy-number variations contribute to CDH in the population. However, most individuals with CDH remain genetically undiagnosed. Here, we perform integrated de novo and common-variant analyses using 1,469 CDH individuals, including 1,064 child-parent trios and 6,133 ancestry-matched, unaffected controls for the genome-wide association study. We identify candidate CDH variants in 15 genes, including eight novel genes, through deleterious de novo variants. We further identify two genomic loci contributing to CDH risk through common variants with similar effect sizes among Europeans and Latinx. Both loci are in putative transcriptional regulatory regions of developmental patterning genes. Estimated heritability in common variants is ∼19%. Strikingly, there is no significant difference in estimated polygenic risk scores between isolated and complex CDH or between individuals harboring deleterious de novo variants and individuals without these variants. The data support a polygenic model as part of the CDH genetic architecture.

2.
Cell Stem Cell ; 31(10): 1465-1483.e6, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39181129

RESUMO

While all eukaryotic cells are dependent on mitochondria for function, in a complex tissue, which cell type and which cell behavior are more sensitive to mitochondrial deficiency remain unpredictable. Here, we show that in the mouse airway, compromising mitochondrial function by inactivating mitochondrial protease gene Lonp1 led to reduced progenitor proliferation and differentiation during development, apoptosis of terminally differentiated ciliated cells and their replacement by basal progenitors and goblet cells during homeostasis, and failed airway progenitor migration into damaged alveoli following influenza infection. ATF4 and the integrated stress response (ISR) pathway are elevated and responsible for the airway phenotypes. Such context-dependent sensitivities are predicted by the selective expression of Bok, which is required for ISR activation. Reduced LONP1 expression is found in chronic obstructive pulmonary disease (COPD) airways with squamous metaplasia. These findings illustrate a cellular energy landscape whereby compromised mitochondrial function could favor the emergence of pathological cell types.


Assuntos
Diferenciação Celular , Mitocôndrias , Proteínas Mitocondriais , Células-Tronco , Animais , Mitocôndrias/metabolismo , Camundongos , Proteínas Mitocondriais/metabolismo , Células-Tronco/metabolismo , Células-Tronco/citologia , Proteases Dependentes de ATP/metabolismo , Proteases Dependentes de ATP/genética , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/metabolismo , Humanos , Proliferação de Células , Camundongos Endogâmicos C57BL , Apoptose
3.
Sci Transl Med ; 16(732): eadc8930, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38295182

RESUMO

A major barrier to the impact of genomic diagnosis in patients with congenital malformations is the lack of understanding regarding how sequence variants contribute to disease pathogenesis and whether this information could be used to generate patient-specific therapies. Congenital diaphragmatic hernia (CDH) is among the most common and severe of all structural malformations; however, its underlying mechanisms are unclear. We identified loss-of-function sequence variants in the epigenomic regulator gene SIN3A in two patients with complex CDH. Tissue-specific deletion of Sin3a in mice resulted in defects in diaphragm development, lung hypoplasia, and pulmonary hypertension, the cardinal features of CDH and major causes of CDH-associated mortality. Loss of SIN3A in the lung mesenchyme resulted in reduced cellular differentiation, impaired cell proliferation, and increased DNA damage. Treatment of embryonic Sin3a mutant mice with anacardic acid, an inhibitor of histone acetyltransferase, reduced DNA damage, increased cell proliferation and differentiation, improved lung and pulmonary vascular development, and reduced pulmonary hypertension. These findings demonstrate that restoring the balance of histone acetylation can improve lung development in the Sin3a mouse model of CDH.


Assuntos
Hérnias Diafragmáticas Congênitas , Hipertensão Pulmonar , Humanos , Camundongos , Animais , Hipertensão Pulmonar/etiologia , Histonas , Acetilação , Hérnias Diafragmáticas Congênitas/genética , Hérnias Diafragmáticas Congênitas/complicações , Hérnias Diafragmáticas Congênitas/patologia , Pulmão/patologia
4.
Am J Hum Genet ; 110(10): 1787-1803, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37751738

RESUMO

Congenital diaphragmatic hernia (CDH) is a relatively common and genetically heterogeneous structural birth defect associated with high mortality and morbidity. We describe eight unrelated families with an X-linked condition characterized by diaphragm defects, variable anterior body-wall anomalies, and/or facial dysmorphism. Using linkage analysis and exome or genome sequencing, we found that missense variants in plastin 3 (PLS3), a gene encoding an actin bundling protein, co-segregate with disease in all families. Loss-of-function variants in PLS3 have been previously associated with X-linked osteoporosis (MIM: 300910), so we used in silico protein modeling and a mouse model to address these seemingly disparate clinical phenotypes. The missense variants in individuals with CDH are located within the actin-binding domains of the protein but are not predicted to affect protein structure, whereas the variants in individuals with osteoporosis are predicted to result in loss of function. A mouse knockin model of a variant identified in one of the CDH-affected families, c.1497G>C (p.Trp499Cys), shows partial perinatal lethality and recapitulates the key findings of the human phenotype, including diaphragm and abdominal-wall defects. Both the mouse model and one adult human male with a CDH-associated PLS3 variant were observed to have increased rather than decreased bone mineral density. Together, these clinical and functional data in humans and mice reveal that specific missense variants affecting the actin-binding domains of PLS3 might have a gain-of-function effect and cause a Mendelian congenital disorder.


Assuntos
Hérnias Diafragmáticas Congênitas , Osteoporose , Adulto , Humanos , Masculino , Animais , Camundongos , Hérnias Diafragmáticas Congênitas/genética , Actinas/genética , Mutação de Sentido Incorreto/genética , Osteoporose/genética
5.
J Perinatol ; 43(10): 1230-1237, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37169914

RESUMO

Patent ductus arteriosus (PDA) is the most common cardiovascular condition diagnosed in premature infants. Acetaminophen was first proposed as a potential treatment for PDA in 2011. Since that time acetaminophen use among extremely preterm neonates has increased substantially. The limited available data demonstrate that acetaminophen reduces PDA without evident hepatotoxicity. These findings have led some to suggest that acetaminophen is a safe and effective therapy for PDA closure. However, the lack of apparent hepatoxicity is predictable. Acetaminophen induced cellular injury is due to CYP2E1 derived metabolites; and hepatocyte CYP2E1 expression is low in the fetal and neonatal period. Here, we review preclinical and clinical data that support the hypothesis that the lung, which expresses high levels of CYP2E1 during fetal and early postnatal development, may be particularly susceptible to acetaminophen induced toxicity. Despite these emerging data, the true potential pulmonary risks and benefits of acetaminophen for PDA closure are largely unknown. The available clinical studies in are marked by significant weakness including low sample sizes and minimal evaluation of extremely preterm infants who are typically at highest risk of pulmonary morbidity. We propose that studies interrogating mechanisms linking developmentally regulated, cell-specific CYP2E1 expression and acetaminophen-induced toxicity as well as robust assessment of pulmonary outcomes in large trials that evaluate the safety and efficacy of acetaminophen in extremely preterm infants are needed.


Assuntos
Permeabilidade do Canal Arterial , Recém-Nascido , Humanos , Permeabilidade do Canal Arterial/tratamento farmacológico , Acetaminofen/uso terapêutico , Indometacina , Recém-Nascido de Baixo Peso , Ibuprofeno/uso terapêutico , Citocromo P-450 CYP2E1 , Lactente Extremamente Prematuro
6.
Am J Physiol Lung Cell Mol Physiol ; 323(1): L1-L13, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35503238

RESUMO

Over the past decade, clinicians have increasingly prescribed acetaminophen (APAP) for patients in the neonatal intensive care unit (NICU). Acetaminophen has been shown to reduce postoperative opiate burden, and may provide similar efficacy for closure of the patent ductus arteriosus (PDA) as nonsteroidal anti-inflammatory drugs (NSAIDs). Despite these potential benefits, APAP exposures have spread to increasingly less mature infants, a highly vulnerable population for whom robust pharmacokinetic and pharmacodynamic data for APAP are lacking. Concerningly, preclinical studies suggest that perinatal APAP exposures may result in unanticipated adverse effects that are unique to the developing lung. In this review, we discuss the clinical observations linking APAP exposures to adverse respiratory outcomes and the preclinical data demonstrating a developmental susceptibility to APAP-induced lung injury. We show how clinical observations linking perinatal APAP exposures to pulmonary injury have been taken to the bench to produce important insights into the potential mechanisms underlying these findings. We argue that the available data support a more cautious approach to APAP use in the NICU until large randomized controlled trials provide appropriate safety and efficacy data.


Assuntos
Acetaminofen , Permeabilidade do Canal Arterial , Acetaminofen/efeitos adversos , Anti-Inflamatórios não Esteroides , Permeabilidade do Canal Arterial/induzido quimicamente , Permeabilidade do Canal Arterial/tratamento farmacológico , Feminino , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Pulmão , Gravidez
7.
Am J Hum Genet ; 108(10): 1964-1980, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34547244

RESUMO

Congenital diaphragmatic hernia (CDH) is a severe congenital anomaly that is often accompanied by other anomalies. Although the role of genetics in the pathogenesis of CDH has been established, only a small number of disease-associated genes have been identified. To further investigate the genetics of CDH, we analyzed de novo coding variants in 827 proband-parent trios and confirmed an overall significant enrichment of damaging de novo variants, especially in constrained genes. We identified LONP1 (lon peptidase 1, mitochondrial) and ALYREF (Aly/REF export factor) as candidate CDH-associated genes on the basis of de novo variants at a false discovery rate below 0.05. We also performed ultra-rare variant association analyses in 748 affected individuals and 11,220 ancestry-matched population control individuals and identified LONP1 as a risk gene contributing to CDH through both de novo and ultra-rare inherited largely heterozygous variants clustered in the core of the domains and segregating with CDH in affected familial individuals. Approximately 3% of our CDH cohort who are heterozygous with ultra-rare predicted damaging variants in LONP1 have a range of clinical phenotypes, including other anomalies in some individuals and higher mortality and requirement for extracorporeal membrane oxygenation. Mice with lung epithelium-specific deletion of Lonp1 die immediately after birth, most likely because of the observed severe reduction of lung growth, a known contributor to the high mortality in humans. Our findings of both de novo and inherited rare variants in the same gene may have implications in the design and analysis for other genetic studies of congenital anomalies.


Assuntos
Proteases Dependentes de ATP/genética , Proteases Dependentes de ATP/fisiologia , Anormalidades Craniofaciais/genética , Variações do Número de Cópias de DNA , Anormalidades do Olho/genética , Transtornos do Crescimento/genética , Hérnias Diafragmáticas Congênitas/genética , Luxação Congênita de Quadril/genética , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/fisiologia , Mutação de Sentido Incorreto , Osteocondrodisplasias/genética , Anormalidades Dentárias/genética , Animais , Estudos de Casos e Controles , Estudos de Coortes , Anormalidades Craniofaciais/patologia , Anormalidades do Olho/patologia , Feminino , Transtornos do Crescimento/patologia , Hérnias Diafragmáticas Congênitas/patologia , Luxação Congênita de Quadril/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteocondrodisplasias/patologia , Linhagem , Anormalidades Dentárias/patologia
8.
Respir Care ; 66(1): 41-49, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32753531

RESUMO

BACKGROUND: Congenital diaphragmatic hernia is associated with a high risk of neonatal mortality and long-term morbidity due to lung hypoplasia, pulmonary hypertension, and prolonged exposure to positive-pressure ventilation. Ventilator-associated lung injury may be reduced by using approaches that facilitate the transition from invasive ventilation to noninvasive ventilation (NIV), such as with neurally-adjusted ventilatory assist (NAVA). We reported our use of NAVA in neonatal patients with congenital diaphragmatic hernia during the transition from invasive ventilation to NIV. METHODS: A retrospective analysis of neonatal subjects with congenital diaphragmatic hernia admitted to a tertiary care children's hospital between December 2015 and May 2018 was conducted. Subject data and factors that affected the use of NAVA were analyzed. RESULTS: Ten neonatal subjects with congenital diaphragmatic hernia were placed on NAVA, and 6 were successfully transitioned, after surgery, from pressure control synchronized intermittent mandatory ventilation to invasive ventilation with NAVA and then to NIV with NAVA without the need for re-intubation. The transition from pressure control synchronized intermittent mandatory ventilation to invasive ventilation with NAVA resulted in a decrease in peak inspiratory pressure, mean airway pressure, and [Formula: see text]. Barriers to the use of NAVA included symptomatic pleural effusion or chylothorax and pulmonary sequestration. CONCLUSIONS: Both invasive ventilation with NAVA and NIV with NAVA were used successfully in subjects with congenital diaphragmatic hernia during the transition from invasive ventilation to NIV. The transition to NAVA was associated with a decrease in peak inspiratory pressure, mean airway pressure, and the need for supplemental oxygen. A prospective trial is needed to determine the short- and long-term impacts of this mode of ventilation in neonates with congenital diaphragmatic hernia.


Assuntos
Hérnias Diafragmáticas Congênitas , Suporte Ventilatório Interativo , Extubação , Criança , Hérnias Diafragmáticas Congênitas/terapia , Humanos , Recém-Nascido , Estudos Prospectivos , Estudos Retrospectivos
9.
Genet Med ; 22(12): 2020-2028, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32719394

RESUMO

PURPOSE: Congenital diaphragmatic hernia (CDH) is associated with significant mortality and long-term morbidity in some but not all individuals. We hypothesize monogenic factors that cause CDH are likely to have pleiotropic effects and be associated with worse clinical outcomes. METHODS: We enrolled and prospectively followed 647 newborns with CDH and performed genomic sequencing on 462 trios to identify de novo variants. We grouped cases into those with and without likely damaging (LD) variants and systematically assessed CDH clinical outcomes between the genetic groups. RESULTS: Complex cases with additional congenital anomalies had higher mortality than isolated cases (P = 8 × 10-6). Isolated cases with LD variants had similar mortality to complex cases and much higher mortality than isolated cases without LD (P = 3 × 10-3). The trend was similar with pulmonary hypertension at 1 month. Cases with LD variants had an estimated 12-17 points lower scores on neurodevelopmental assessments at 2 years compared with cases without LD variants, and this difference is similar in isolated and complex cases. CONCLUSION: We found that the LD genetic variants are associated with higher mortality, worse pulmonary hypertension, and worse neurodevelopment outcomes compared with non-LD variants. Our results have important implications for prognosis, potential intervention and long-term follow up for children with CDH.


Assuntos
Hérnias Diafragmáticas Congênitas , Criança , Hérnias Diafragmáticas Congênitas/genética , Humanos , Recém-Nascido , Estudos Retrospectivos
10.
J Clin Invest ; 128(2): 655-667, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29251627

RESUMO

A critical event in the adaptation to extrauterine life is relaxation of the pulmonary vasculature at birth, allowing for a rapid increase in pulmonary blood flow that is essential for efficient gas exchange. Failure of this transition leads to pulmonary hypertension (PH), a major cause of newborn mortality associated with preterm birth, infection, hypoxia, and malformations including congenital diaphragmatic hernia (CDH). While individual vasoconstrictor and dilator genes have been identified, the coordination of their expression is not well understood. Here, we found that lung mesenchyme-specific deletion of CDH-implicated genes encoding pre-B cell leukemia transcription factors (Pbx) led to lethal PH in mice shortly after birth. Loss of Pbx genes resulted in the misexpression of both vasoconstrictors and vasodilators in multiple pathways that converge to increase phosphorylation of myosin in vascular smooth muscle (VSM) cells, causing persistent constriction. While targeting endothelin and angiotensin, which are upstream regulators that promote VSM contraction, was not effective, treatment with the Rho-kinase inhibitor Y-27632 reduced vessel constriction and PH in Pbx-mutant mice. These results demonstrate a lung-intrinsic, herniation-independent cause of PH in CDH. More broadly, our findings indicate that neonatal PH can result from perturbation of multiple pathways and suggest that targeting the downstream common effectors may be a more effective treatment for neonatal PH.


Assuntos
Hérnias Diafragmáticas Congênitas/etiologia , Proteínas de Homeodomínio/metabolismo , Pulmão/embriologia , Fator de Transcrição 1 de Leucemia de Células Pré-B/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Alelos , Animais , Apoptose , Proliferação de Células , Modelos Animais de Doenças , Ecocardiografia , Elastina/metabolismo , Feminino , Deleção de Genes , Hipertensão Pulmonar/etiologia , Pulmão/irrigação sanguínea , Camundongos , Camundongos Knockout , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Miosinas/metabolismo , Parto , Fosforilação , Artéria Pulmonar/metabolismo , Respiração , Vasoconstrição/fisiologia
11.
Dis Model Mech ; 10(8): 955-970, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28768736

RESUMO

Congenital diaphragmatic hernias (CDHs) and structural anomalies of the diaphragm are a common class of congenital birth defects that are associated with significant morbidity and mortality due to associated pulmonary hypoplasia, pulmonary hypertension and heart failure. In ∼30% of CDH patients, genomic analyses have identified a range of genetic defects, including chromosomal anomalies, copy number variants and sequence variants. The affected genes identified in CDH patients include transcription factors, such as GATA4, ZFPM2, NR2F2 and WT1, and signaling pathway components, including members of the retinoic acid pathway. Mutations in these genes affect diaphragm development and can have pleiotropic effects on pulmonary and cardiac development. New therapies, including fetal endoscopic tracheal occlusion and prenatal transplacental fetal treatments, aim to normalize lung development and pulmonary vascular tone to prevent and treat lung hypoplasia and pulmonary hypertension, respectively. Studies of the association between particular genetic mutations and clinical outcomes should allow us to better understand the origin of this birth defect and to improve our ability to predict and identify patients most likely to benefit from specialized treatment strategies.


Assuntos
Predisposição Genética para Doença , Hérnias Diafragmáticas Congênitas/genética , Hérnias Diafragmáticas Congênitas/terapia , Animais , Diafragma/anormalidades , Diafragma/patologia , Modelos Animais de Doenças , Humanos
12.
Development ; 143(5): 774-9, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26811383

RESUMO

Congenital heart defects are the most common birth defects in humans, and those that affect the proper alignment of the outflow tracts and septation of the ventricles are a highly significant cause of morbidity and mortality in infants. A late differentiating population of cardiac progenitors, referred to as the anterior second heart field (AHF), gives rise to the outflow tract and the majority of the right ventricle and provides an embryological context for understanding cardiac outflow tract alignment and membranous ventricular septal defects. However, the transcriptional pathways controlling AHF development and their roles in congenital heart defects remain incompletely elucidated. Here, we inactivated the gene encoding the transcription factor MEF2C in the AHF in mice. Loss of Mef2c function in the AHF results in a spectrum of outflow tract alignment defects ranging from overriding aorta to double-outlet right ventricle and dextro-transposition of the great arteries. We identify Tdgf1, which encodes a Nodal co-receptor (also known as Cripto), as a direct transcriptional target of MEF2C in the outflow tract via an AHF-restricted Tdgf1 enhancer. Importantly, both the MEF2C and TDGF1 genes are associated with congenital heart defects in humans. Thus, these studies establish a direct transcriptional pathway between the core cardiac transcription factor MEF2C and the human congenital heart disease gene TDGF1. Moreover, we found a range of outflow tract alignment defects resulting from a single genetic lesion, supporting the idea that AHF-derived outflow tract alignment defects may constitute an embryological spectrum rather than distinct anomalies.


Assuntos
Fator de Crescimento Epidérmico/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Glicoproteínas de Membrana/fisiologia , Proteínas de Neoplasias/fisiologia , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Fator de Crescimento Epidérmico/genética , Feminino , Deleção de Genes , Coração/embriologia , Cardiopatias Congênitas/genética , Comunicação Interventricular/genética , Ventrículos do Coração , Humanos , Hibridização In Situ , Fatores de Transcrição MEF2/genética , Fatores de Transcrição MEF2/fisiologia , Masculino , Glicoproteínas de Membrana/genética , Camundongos , Morfogênese/genética , Proteínas de Neoplasias/genética , Organogênese , Análise de Sequência de RNA , Distribuição Tecidual , Transcrição Gênica , Transposição dos Grandes Vasos/genética
13.
Dev Dyn ; 245(4): 497-507, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26813283

RESUMO

BACKGROUND: Fras1 encodes an extracellular matrix protein that is critical for the establishment of the epidermal basement membrane during gestation. In humans, mutations in FRAS1 cause Fraser Syndrome (FS), a pleiotropic condition with many clinical presentations such as limb, eye, kidney, and craniofacial deformations. Many of these defects are mimicked by loss of Fras1 in mice, and are preceded by the formation of epidermal blisters in utero. RESULTS: In this study, we identified a novel ENU-derived rounded foot (rdf) mouse mutant with highly penetrant hindlimb soft-tissue syndactyly, among other structural defects. Mapping and sequencing revealed that rdf is a novel loss-of-function nonsense allele of Fras1 (Fras1(rdf)). Focusing on the limb, we found that the Fras1(rdf) syndactyly phenotype originates from loss of interdigital cell death (ICD). Despite normal expression of bone morphogenetic protein (BMP) ligands and their receptors, the BMP downstream target gene Msx2, which is also necessary and sufficient to promote ICD, was down-regulated in the interdigital regions of Fras1(rdf) hindlimb buds. CONCLUSIONS: The close correlation between limb bud epidermal blistering, decreased Msx2 expression, and reduced ICD in the Fras1(rdf) hindlimb buds suggests that epithelium detachment from the mesenchyme may create a physical gap that interrupts the transmission of BMP, among other signals, resulting in soft tissue syndactyly.


Assuntos
Apoptose , Proteínas da Matriz Extracelular/metabolismo , Membro Posterior/embriologia , Mutação , Sindactilia/embriologia , Animais , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas da Matriz Extracelular/genética , Membro Posterior/patologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos , Camundongos Mutantes , Sindactilia/genética , Sindactilia/patologia
15.
Curr Top Dev Biol ; 100: 253-77, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22449847

RESUMO

Congenital heart disease is a major cause of morbidity and mortality throughout life. Mutations in numerous transcription factors have been identified in patients and families with some of the most common forms of cardiac malformations and arrhythmias. This review discusses transcription factor pathways known to be important for normal heart development and how abnormalities in these pathways have been linked to morphological and functional forms of congenital heart defects. A comprehensive, current list of known transcription factor mutations associated with congenital heart disease is provided, but the review focuses primarily on three key transcription factors, Nkx2-5, GATA4, and Tbx5, and their known biochemical and genetic partners. By understanding the interaction partners, transcriptional targets, and upstream activators of these core cardiac transcription factors, additional information about normal heart formation and further insight into genes and pathways affected in congenital heart disease should result.


Assuntos
Cardiopatias Congênitas/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Animais , Coração/embriologia , Cardiopatias Congênitas/genética , Humanos , Miocárdio/citologia , Fatores de Transcrição/genética
16.
Nat Genet ; 44(1): 89-93, 2011 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-22138689

RESUMO

Development and function of the human heart depend on the dynamic control of tissue-specific gene expression by distant-acting transcriptional enhancers. To generate an accurate genome-wide map of human heart enhancers, we used an epigenomic enhancer discovery approach and identified ∼6,200 candidate enhancer sequences directly from fetal and adult human heart tissue. Consistent with their predicted function, these elements were markedly enriched near genes implicated in heart development, function and disease. To further validate their in vivo enhancer activity, we tested 65 of these human sequences in a transgenic mouse enhancer assay and observed that 43 (66%) drove reproducible reporter gene expression in the heart. These results support the discovery of a genome-wide set of noncoding sequences highly enriched in human heart enhancers that is likely to facilitate downstream studies of the role of enhancers in development and pathological conditions of the heart.


Assuntos
Elementos Facilitadores Genéticos , Coração/fisiologia , Adulto , Animais , Mapeamento Cromossômico , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Humanos , Camundongos , Camundongos Transgênicos , Fatores de Transcrição de p300-CBP
17.
Development ; 138(12): 2555-65, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21610032

RESUMO

Waardenburg syndromes are characterized by pigmentation and autosensory hearing defects, and mutations in genes encoding transcription factors that control neural crest specification and differentiation are often associated with Waardenburg and related disorders. For example, mutations in SOX10 result in a severe form of Waardenburg syndrome, Type IV, also known as Waardenburg-Hirschsprung disease, characterized by pigmentation and other neural crest defects, including defective innervation of the gut. SOX10 controls neural crest development through interactions with other transcription factors. The MADS box transcription factor MEF2C is an important regulator of brain, skeleton, lymphocyte and cardiovascular development and is required in the neural crest for craniofacial development. Here, we establish a novel role for MEF2C in melanocyte development. Inactivation of Mef2c in the neural crest of mice results in reduced expression of melanocyte genes during development and a significant loss of pigmentation at birth due to defective differentiation and reduced abundance of melanocytes. We identify a transcriptional enhancer of Mef2c that directs expression to the neural crest and its derivatives, including melanocytes, in transgenic mouse embryos. This novel Mef2c neural crest enhancer contains three functional SOX binding sites and a single essential MEF2 site. We demonstrate that Mef2c is a direct transcriptional target of SOX10 and MEF2 via this evolutionarily conserved enhancer. Furthermore, we show that SOX10 and MEF2C physically interact and function cooperatively to activate the Mef2c gene in a feed-forward transcriptional circuit, suggesting that MEF2C might serve as a potentiator of the transcriptional pathways affected in Waardenburg syndromes.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Melanócitos/citologia , Fatores de Regulação Miogênica/fisiologia , Fatores de Transcrição SOXE/fisiologia , Transcrição Gênica , Animais , Embrião de Mamíferos , Doença de Hirschsprung , Fatores de Transcrição MEF2 , Camundongos , Camundongos Transgênicos , Crista Neural/crescimento & desenvolvimento , Síndrome de Waardenburg/genética
18.
Nat Genet ; 42(9): 806-10, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20729851

RESUMO

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme noncoding-sequence conservation has successfully predicted enhancers that are active in many tissues but has failed to identify substantial numbers of heart-specific enhancers. Here, we used ChIP-Seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over 3,000 candidate heart enhancers genome wide. Compared to enhancers active in other tissues we studied at this time point, most candidate heart enhancers were less deeply conserved in vertebrate evolution. Nevertheless, transgenic mouse assays of 130 candidate regions revealed that most function reproducibly as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary conservation of embryonic enhancers can vary depending on tissue type.


Assuntos
Imunoprecipitação da Cromatina/métodos , Elementos Facilitadores Genéticos/genética , Miocárdio/metabolismo , Análise de Sequência de DNA/métodos , Animais , Sequência de Bases , Sequência Conservada/genética , Embrião de Mamíferos , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Humanos , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Especificidade de Órgãos/genética , Filogenia , Vertebrados/genética , Vertebrados/metabolismo
19.
Dev Dyn ; 237(11): 3200-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18924235

RESUMO

The endocardial cushions play a critical role in septation of the four-chambered mammalian heart and in the formation of the valve leaflets that control blood flow through the heart. Within the outflow tract (OFT), both cardiac neural crest and endocardial-derived mesenchymal cells contribute to the endocardial cushions. Bone morphogenetic protein 4 (BMP4) is required for endocardial cushion development and for normal septation of the OFT. In the present study, we show that anterior heart field (AHF)-derived myocardium is an essential source of BMP4 required for normal endocardial cushion expansion and remodeling. Loss of BMP4 from the AHF in mice results in an insufficient number of cells in the developing OFT endocardial cushions, defective cushion remodeling, ventricular septal defects, persistent truncus arteriosus, and abnormal semilunar valve formation.


Assuntos
Septo Interatrial/embriologia , Proteína Morfogenética Óssea 4/biossíntese , Coxins Endocárdicos/embriologia , Septos Cardíacos/embriologia , Valvas Cardíacas/metabolismo , Animais , Septo Interatrial/citologia , Proteína Morfogenética Óssea 4/genética , Coxins Endocárdicos/citologia , Septos Cardíacos/citologia , Valvas Cardíacas/citologia , Mesoderma/citologia , Mesoderma/embriologia , Camundongos , Camundongos Knockout , Crista Neural/citologia , Crista Neural/embriologia
20.
Dev Cell ; 12(4): 645-52, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17420000

RESUMO

MEF2 transcription factors are well-established regulators of muscle development. We have discovered an unanticipated role for MEF2C in the neural crest, where tissue-specific inactivation results in neonatal lethality due to severe craniofacial defects. We show that MEF2C is required for expression of the Dlx5, Dlx6, and Hand2 transcription factor genes in the branchial arches, and we identify a branchial arch-specific enhancer in the Dlx5/6 locus, which is activated synergistically by MEF2C and Dlx5, demonstrating that these factors interact to induce transcription. Mef2c and Dlx5/6 also interact genetically. Mice heterozygous for either Dlx5/6 or Mef2c are normal at birth and survive to weaning. By contrast, heterozygosity for both Mef2c and Dlx5/6 results in defective palate development and neonatal lethality. Taken together, the studies presented here define a feed-forward transcriptional circuit between the MADS-box transcription factor MEF2C and the homeodomain transcription factors Dlx5 and Dlx6 in craniofacial development.


Assuntos
Região Branquial/metabolismo , Face/embriologia , Fatores de Regulação Miogênica/metabolismo , Crista Neural/metabolismo , Crânio/embriologia , Fatores de Transcrição/metabolismo , Obstrução das Vias Respiratórias/embriologia , Obstrução das Vias Respiratórias/mortalidade , Animais , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Elementos Facilitadores Genéticos , Marcação de Genes , Heterozigoto , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição MEF2 , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Fatores de Regulação Miogênica/genética , Fatores de Regulação Miogênica/fisiologia , Células NIH 3T3 , Crânio/metabolismo , Fatores de Transcrição/genética , Transfecção
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