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1.
Nat Commun ; 10(1): 3993, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488837

RESUMO

Planar cell polarity (PCP) plays crucial roles in developmental processes such as gastrulation, neural tube closure and hearing. Wnt pathway mutants are often classified as PCP mutants due to similarities between their phenotypes. Here, we show that in the zebrafish lateral line, disruptions of the PCP and Wnt pathways have differential effects on hair cell orientations. While mutations in the PCP genes vangl2 and scrib cause random orientations of hair cells, mutations in wnt11f1, gpc4 and fzd7a/b induce hair cells to adopt a concentric pattern. This concentric pattern is not caused by defects in PCP but is due to misaligned support cells. The molecular basis of the support cell defect is unknown but we demonstrate that the PCP and Wnt pathways work in parallel to establish proper hair cell orientation. Consequently, hair cell orientation defects are not solely explained by defects in PCP signaling, and some hair cell phenotypes warrant re-evaluation.


Assuntos
Polaridade Celular/genética , Polaridade Celular/fisiologia , Células Ciliadas Auditivas/metabolismo , Via de Sinalização Wnt/genética , Via de Sinalização Wnt/fisiologia , Peixe-Zebra/genética , Animais , Regulação da Expressão Gênica no Desenvolvimento , Proteoglicanas de Heparan Sulfato/genética , Proteínas de Membrana/genética , Morfogênese/genética , Morfogênese/fisiologia , Mutação , Defeitos do Tubo Neural/genética , Neurulação/genética , Receptores de Superfície Celular/genética , Proteína Wnt1/genética , Proteínas de Peixe-Zebra/genética
2.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(8): 769-772, 2019 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-31400124

RESUMO

OBJECTIVE: To explore the characteristics of differentially methylated genes and gene ontology associated with neural tube defects (NTDs). METHODS: Twelve subjects from 3 NTDs pedigrees were enrolled. Patients with NTDs have served as the case group, while their family members with normal phenotypes have served as the control group. Genomic DNA was extracted from peripheral venous blood samples of the families and used for DNA methylation analysis. Pairwise comparison was carried out primarily for patient-offspring pairs, and co-segregation of methylation pattern with NTDs was analyzed. Pathway related to differentially methylated genes was predicted with DAVID software. RESULTS: Pairwise comparison indicated that VTRNA2-1 was the only gene in which all CpG sites were methylated. Co-segregation of VTRNA2-1 gene methylation with NTDs was found in all pedigrees. Pathways of hypermethylated genes included plasma membrane component, regulation of cellular protein metabolic process, and regulation of actin cytoskeleton organization, while the pathways of hypomethylated genes have included transcription regulator activity, cell adhesion, and neuronal differentiation. CONCLUSION: Methylation of the VTRNA2-1 gene has co-segregated with NTDs in the studied pedigrees. The pathways of differentially methylated genes has involved with mechanism of neural tube development.


Assuntos
Metilação de DNA , MicroRNAs/genética , Defeitos do Tubo Neural/genética , Ilhas de CpG , Ontologia Genética , Humanos , Linhagem
4.
Pathobiology ; 86(4): 190-200, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31238314

RESUMO

OBJECTIVE: This study aims to investigate the association of 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and methionine synthase reductase (MTRR A66G) gene polymorphisms with neural tube defects (NTDs) in a Tunisian population. METHODS: Genotyping was performed by polymerase chain reaction with restriction fragment length polymorphisms (PCR-RFLPs) using the restriction enzymes. Allele and genotype frequencies were compared between mothers and fathers of fetuses with NTDs with matched controls based on an association analysis using SPSS software. RESULTS: MTHFR (C677T, A1298C) and MTRR A66G polymorphisms were found to be protector factors for NTD fetuses in the mother group. In addition, a combination of the three wild-type alleles C677/A1298/A66 has increased four-fold the incidence of NTDs (p = 0.004, OR = 3.96, 95% CI: 1.53-10.23). In the father group, MTHFR C677T was a risk factor for NTDs. However, no association was found between MTHFR A1298C, MTRR A66G, and the occurrence of this anomaly. The analysis of MTHFR C677T and MTRR A66G polymorphisms has demonstrated a significant difference in vitamin B12 levels between recessive and dominant genotypes in case mothers (p < 0.05). CONCLUSION: Additional studies are required to better understand the roles of parental gene polymorphisms related to folate-homocysteine metabolism in the pathogenesis of NTD.


Assuntos
Ferredoxina-NADP Redutase/genética , Predisposição Genética para Doença , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Defeitos do Tubo Neural/genética , Polimorfismo de Nucleotídeo Único , Alelos , Pai , Feminino , Ácido Fólico/metabolismo , Genótipo , Homocisteína/metabolismo , Homocistinúria/genética , Humanos , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/deficiência , Mães , Espasticidade Muscular/genética , Defeitos do Tubo Neural/fisiopatologia , Polimorfismo de Fragmento de Restrição , Gravidez , Transtornos Psicóticos/genética , Tunísia
5.
BMC Genomics ; 20(1): 386, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101013

RESUMO

BACKGROUND: Adenovirus protein, Gam1, triggers the proteolytic destruction of the E1 SUMO-activating enzyme. Microinjection of an empirically determined amount of Gam1 mRNA into one-cell Xenopus embryos can reduce SUMOylation activity to undetectable, but nonlethal, levels, enabling an examination of the role of this post-translational modification during early vertebrate development. RESULTS: We find that SUMOylation-deficient embryos consistently exhibit defects in neural tube and heart development. We have measured differences in gene expression between control and embryos injected with Gam1 mRNA at three developmental stages: early gastrula (immediately following the initiation of zygotic transcription), late gastrula (completion of the formation of the three primary germ layers), and early neurula (appearance of the neural plate). Although changes in gene expression are widespread and can be linked to many biological processes, three pathways, non-canonical Wnt/PCP, snail/twist, and Ets-1, are especially sensitive to the loss of SUMOylation activity and can largely account for the predominant phenotypes of Gam1 embryos. SUMOylation appears to generate different pools of a given transcription factor having different specificities with this post-translational modification involved in the regulation of more complex, as opposed to housekeeping, processes. CONCLUSIONS: We have identified changes in gene expression that underlie the neural tube and heart phenotypes resulting from depressed SUMOylation activity. Notably, these developmental defects correspond to the two most frequently occurring congenital birth defects in humans, strongly suggesting that perturbation of SUMOylation, either globally or of a specific protein, may frequently be the origin of these pathologies.


Assuntos
Embrião de Mamíferos/patologia , Regulação da Expressão Gênica no Desenvolvimento , Cardiopatias Congênitas/genética , Defeitos do Tubo Neural/genética , Sumoilação , Proteínas de Xenopus/metabolismo , Animais , Embrião de Mamíferos/metabolismo , Feminino , Perfilação da Expressão Gênica , Cardiopatias Congênitas/patologia , Masculino , Defeitos do Tubo Neural/patologia , Proteínas Virais/administração & dosagem , Xenopus laevis
6.
Hum Genet ; 138(7): 703-713, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31139930

RESUMO

Neural tube defects (NTD) result from complex mechanisms between genes, nutrition and environment. The identification of genetic predictors by genome exome sequencing and their influence on genome methylation need further consideration. Gene variants related to 1-CM metabolism (1-CM) could influence the methylation of genes involved in neural tube embryogenesis through impaired synthesis of S-adenosyl methionine. We performed exome sequencing of 6116 genes referenced in OMIM and NTD risk and genome-wide methylation in 23 NTD cases. We replicated the most significant associations in 81 other cases. The analysis of exome sequencing identified one gene of 1-CM, LRP2, and one gene of Sonic Hedgehog (SHH), GLI3, in the 23 NTD cases. The analysis restricted to genes of 1-CM and neural tube embryogenesis identified five gene predictors of 1-CM (LRP2, rs137983840; MMAA, rs148142853; TCN2, rs35838082; FPGS, rs41306702; BHMT, rs763726268) and two of SHH (GLI3, rs35364414; MKS1, rs151023718). We replicated the association of TCN2, BHMT and GLI3 with NTD risk in the 81 cases. We found a significant hemimethylation of CFAP46 that may influence SHH activation in one case, who carried risk alleles in BHMT, LRP2, MMAA and GLI3. In conclusion, we identified new candidate genes and rare variants that highlight an interacting influence of genes involved in SHH and 1-CM in the puzzle of genetic components of NTD risk.


Assuntos
Biomarcadores/metabolismo , Carbono/metabolismo , Exoma , Proteínas Hedgehog/genética , Defeitos do Tubo Neural/genética , Vitamina B 12/metabolismo , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Humanos , Masculino , Defeitos do Tubo Neural/metabolismo , Defeitos do Tubo Neural/patologia , Transdução de Sinais , Sequenciamento Completo do Exoma , Adulto Jovem
7.
Mol Biol Rep ; 46(3): 3193-3201, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30941645

RESUMO

Folate is an essential micronutrient during pregnancy. The differential expression of genes related to folate transport and metabolism during the advancing gestation and pregnancy complications is not well established. Hence, we studied the gene expression of folate metabolism and transport proteins in the placenta with advancing gestation, preeclampsia and neural tube defects (NTD). The expression of folate transporters and enzymes involved in folate metabolism in the placenta with advancing gestation and pregnancy-related disorders were studied by 2-step RT-PCR. Folate levels were estimated by microbiological assay using Lactobacillus casei. Significant changes in levels of placental folate metabolizing enzymes were found in both physiological and pathological pregnancies during advancing gestation. Expression of methyltetrahydrofolate reductase (MTHFR) (p < 0.001) and cystathionine-ß-synthase (CBS) (p < 0.001) was decreased while that of methionine synthase (MS) (p < 0.001) was increased with advancing gestation. A much-reduced expression of MTHFR (p < 0.01) and an abnormally high expression of methionine synthase reductase (p < 0.001) were observed in the NTD group. In NTDs, there was an adaptive up-regulation of folate transporters mainly reduced folate carrier (p < 0.001) and folate receptor alpha (p < 0.001). MTHFR expression showed a strong positive correlation (r = 0.96, p < 0.01) with folate levels in placenta. Pregnant women with preeclampsia had low expression of MS (p < 0.01) in association with low folate levels. Placental folate metabolizing enzymes exhibited a differential pattern during advancing gestation. Deficient folate status in association with alteration in expression of enzymes involved in folate metabolism might be associated with pregnancy complications such as preeclampsia and NTDs.


Assuntos
Ácido Fólico/metabolismo , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo , Organogênese/genética , Placenta/metabolismo , Pré-Eclâmpsia/genética , Pré-Eclâmpsia/metabolismo , Adulto , Transporte Biológico , Feminino , Regulação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Humanos , Redes e Vias Metabólicas , Placenta/embriologia , Pré-Eclâmpsia/fisiopatologia , Gravidez , Adulto Jovem
8.
Ital J Pediatr ; 45(1): 37, 2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30867013

RESUMO

BACKGROUND: Neural tube defects (NTDs) are birth defects of the brain, spine, or spinal cord invoked by the insufficient intake of folic acid in the early stages of pregnancy and have a complex etiology involving both genetic and environmental factors. So the study aimed to explore the association between alterations in maternal one-carbon metabolism and NTDs in the offspring. METHODS: We conducted a case-control study to get a deeper insight into this association, as well as into the role of genetic polymorphisms. Plasma concentrations of folate, homocysteine (Hcy), S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH) and genotypes and alleles distributions of 52 SNPs in 8 genes were compared for 61 women with NTDs-affected offspring and 61 women with healthy ones. RESULTS: There were significant differences between groups with regard to plasma folate, SAM, SAH and SAM/SAH levels. Logistic regression results revealed a significant association between maternal plasma folate level and risk of NTDs in the offspring. For MTHFD1 rs2236225 polymorphism, mothers having GA genotype and A allele exhibited an increased risk of NTDs in the offspring (OR = 2.600, 95%CI: 1.227-5.529; OR = 1.847, 95%CI: 1.047-3.259). For MTHFR rs1801133 polymorphism, mothers having TT and CT genotypes were more likely to affect NTDs in the offspring (OR = 4.105, 95%CI: 1.271-13.258; OR = 3.333, 95%CI: 1.068-10.400). Moreover, mothers carrying T allele had a higher risk of NTDs in the offspring (OR = 1.798, 95%CI: 1.070-3.021). For MTRR rs1801394 polymorphism, the frequency of G allele was significantly higher in cases than in controls (OR = 1.763, 95%CI: 1.023-3.036). Mothers with NTDs-affected children had higher AG genotype in RFC1 rs1051226 polymorphism than controls, manifesting an increased risk for NTDs (OR = 3.923, 95%CI: 1.361-11.308). CONCLUSION: Folic acid deficiency, MTHFD1 rs2236225, MTHFR rs1801133, MTRR rs1801349 and RFC1 rs1051226 polymorphisms may be maternal risk factors of NTDs.


Assuntos
Deficiência de Ácido Fólico/genética , Predisposição Genética para Doença/epidemiologia , Defeitos do Tubo Neural/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Carbono/metabolismo , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , China , Feminino , Ferredoxina-NADP Redutase/genética , Deficiência de Ácido Fólico/diagnóstico , Deficiência de Ácido Fólico/epidemiologia , Marcadores Genéticos/genética , Genótipo , Humanos , Recém-Nascido , Modelos Logísticos , Masculino , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Antígenos de Histocompatibilidade Menor/genética , Defeitos do Tubo Neural/epidemiologia , Defeitos do Tubo Neural/fisiopatologia , Razão de Chances , Gravidez , Valores de Referência
9.
PLoS One ; 14(3): e0214063, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30889190

RESUMO

Neural tube defects (NTDs), one of the most common birth defects in human, present a multifactorial etiology with a poorly defined genetic component. The Dlx5 and Dlx6 bigenic cluster encodes two evolutionary conserved homeodomain transcription factors, which are necessary for proper vertebrate development. It has been shown that Dlx5/6 genes are essential for anterior neural tube closure, however their role in the formation of the posterior structures has never been described. Here, we show that Dlx5/6 expression is required during vertebrate posterior axis formation. Dlx5 presents a similar expression pattern in neural plate border cells during posterior neurulation of zebrafish and mouse. Dlx5/6-inactivation in the mouse results in a phenotype reminiscent of NTDs characterized by open thoracic and lumbar vertebral arches and failure of epaxial muscle formation at the dorsal midline. The dlx5a/6a zebrafish morphants present posterior NTDs associated with abnormal delamination of neural crest cells showing altered expression of cell adhesion molecules and defects of motoneuronal development. Our findings provide new molecular leads to decipher the mechanisms of vertebrate posterior neurulation and might help to gather a better understanding of human congenital NTDs etiology.


Assuntos
Proteínas de Homeodomínio/metabolismo , Placa Neural/embriologia , Placa Neural/metabolismo , Fatores de Transcrição/metabolismo , Animais , Padronização Corporal/genética , Padronização Corporal/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Proteínas de Homeodomínio/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Família Multigênica , Defeitos do Tubo Neural/embriologia , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo , Neurulação/genética , Neurulação/fisiologia , Gravidez , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/deficiência , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
10.
Nat Commun ; 10(1): 953, 2019 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-30814516

RESUMO

Although hundreds of cytosolic or transmembrane molecules form the primary cilium, few secreted molecules are known to contribute to ciliogenesis. Here, homologous secreted metalloproteases ADAMTS9 and ADAMTS20 are identified as ciliogenesis regulators that act intracellularly. Secreted and furin-processed ADAMTS9 bound heparan sulfate and was internalized by LRP1, LRP2 and clathrin-mediated endocytosis to be gathered in Rab11 vesicles with a unique periciliary localization defined by super-resolution microscopy. CRISPR-Cas9 inactivation of ADAMTS9 impaired ciliogenesis in RPE-1 cells, which was restored by catalytically active ADAMTS9 or ADAMTS20 acting in trans, but not by their proteolytically inactive mutants. Their mutagenesis in mice impaired neural and yolk sac ciliogenesis, leading to morphogenetic anomalies resulting from impaired hedgehog signaling, which is transduced by primary cilia. In addition to their cognate extracellular proteolytic activity, ADAMTS9 and ADAMTS20 thus have an additional proteolytic role intracellularly, revealing an unexpected regulatory dimension in ciliogenesis.


Assuntos
Proteínas ADAMTS/metabolismo , Proteína ADAMTS9/metabolismo , Cílios/metabolismo , Cílios/ultraestrutura , Proteínas ADAMTS/deficiência , Proteínas ADAMTS/genética , Proteína ADAMTS9/deficiência , Proteína ADAMTS9/genética , Animais , Linhagem Celular , Endocitose , Técnicas de Inativação de Genes , Humanos , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Microscopia Eletrônica de Varredura , Modelos Biológicos , Mutação , Defeitos do Tubo Neural/embriologia , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo , Proteólise , Transdução de Sinais , Versicanas/genética , Versicanas/metabolismo , Saco Vitelino/embriologia , Saco Vitelino/metabolismo
11.
Hum Genet ; 138(4): 363-374, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30838450

RESUMO

Neural tube defect disorders are developmental diseases that originate from an incomplete closure of the neural tube during embryogenesis. Despite high prevalence-1 out of 3000 live births-their etiology is not yet established and both environmental and genetic factors have been proposed, with a heritability rate of about 60%. Studies in mouse models as well as in human have further suggested a multifactorial pattern of inheritance for neural tube defect disorders. Here, we report results obtained from clinical diagnosis and NGS analysis of a cohort composed of 52 patients. Using a candidate gene panel approach, we identified variants in known genes of planar cell polarity (PCP) pathway, although with higher prevalence than previously reported. Our study also reveals variants in novel genes such as FREM2 and DISP1. Altogether, these results confirm the implication of the PCP genes and involve the FRAS/FREM2 complex and Sonic Hedgehog signaling as novel components in the appearance of NTDs.


Assuntos
Polaridade Celular/genética , Estudos de Associação Genética/métodos , Defeitos do Tubo Neural/genética , Análise de Sequência de DNA/métodos , Adulto , Animais , Criança , Estudos de Coortes , Análise Mutacional de DNA/métodos , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Defeitos do Tubo Neural/patologia , Gravidez , Transdução de Sinais/genética , Transcriptoma
12.
J Vet Diagn Invest ; 31(2): 228-234, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30852979

RESUMO

A 15-d-old female crossbreed calf was referred because of paraplegia since birth. Clinical examination revealed a skin defect covered by hair on the dorsal midline in the thoracic area of the spine. Thoracolumbar spinal cord neuroanatomic localization was determined based on neurologic examination. Computed tomography of the thoracolumbar spine revealed incomplete fusion of the vertebral arches from T6 to T10 and duplication of the vertebral arch of T7. At the level of T6-T7, duplication of the spinal cord with 2 segments completely separated by a septum of hyperattenuating, probably cartilaginous, tissue was noted. Histologically, the spinal segments had different degrees of duplication. Three central canals were detected in one region. Genetic investigation for the presence of methylenetetrahydrofolate reductase (MTHFR) polymorphism, which has been investigated in both human and veterinary medicine as a possible cause of neural tube defects and abortion, was carried out and was negative in both the calf and her dam.


Assuntos
Doenças dos Bovinos/congênito , Defeitos do Tubo Neural/veterinária , Animais , Bovinos , Doenças dos Bovinos/genética , Doenças dos Bovinos/patologia , Feminino , Predisposição Genética para Doença , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/patologia , Gravidez
13.
Am J Clin Nutr ; 109(3): 674-683, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30848279

RESUMO

BACKGROUND: The risk of neural tube defects (NTDs) is influenced by nutritional factors and genetic determinants of one-carbon metabolism. A key pathway of this metabolism is the vitamin B-12- and folate-dependent remethylation of homocysteine, which depends on methionine synthase (MS, encoded by MTR), methionine synthase reductase, and methylenetetrahydrofolate reductase. Methionine, the product of this pathway, is the direct precursor of S-adenosylmethionine (SAM), the universal methyl donor needed for epigenetic mechanisms. OBJECTIVES: This study aimed to evaluate whether the availability of vitamin B-12 and folate and the expression or activity of the target enzymes of the remethylation pathway are involved in NTD risk. METHODS: We studied folate and vitamin B-12 concentrations and activity, expression, and gene variants of the 3 enzymes in liver from 14 NTD and 16 non-NTD fetuses. We replicated the main findings in cord blood from pregnancies of 41 NTD fetuses compared with 21 fetuses with polymalformations (metabolic and genetic findings) and 375 control pregnancies (genetic findings). RESULTS: The tissue concentration of vitamin B-12 (P = 0.003), but not folate, and the activity (P = 0.001), transcriptional level (P = 0.016), and protein expression (P = 0.003) of MS were decreased and the truncated inactive isoforms of MS were increased in NTD livers. SAM was significantly correlated with MS activity and vitamin B-12. A gene variant in exon 1 of GIF (Gastric Intrinsic Factor gene) was associated with a dramatic decrease of liver vitamin B-12 in 2 cases. We confirmed the decreased vitamin B-12 in cord blood from NTD pregnancies. A gene variant of GIF exon 3 was associated with NTD risk. CONCLUSIONS: The decreased vitamin B-12 in liver and cord blood and decreased expression and activity of MS in liver point out the impaired remethylation pathway as hallmarks associated with NTD risk. We suggest evaluating vitamin B-12 in the nutritional recommendations for prevention of NTD risk beside folate fortification or supplementation.


Assuntos
5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/genética , Doenças Fetais/enzimologia , Fígado/metabolismo , Defeitos do Tubo Neural/enzimologia , Vitamina B 12/metabolismo , 5-Metiltetra-Hidrofolato-Homocisteína S-Metiltransferase/metabolismo , Estudos de Casos e Controles , Feminino , Ferredoxina-NADP Redutase/genética , Ferredoxina-NADP Redutase/metabolismo , Doenças Fetais/genética , Doenças Fetais/metabolismo , Ácido Fólico/análise , Ácido Fólico/metabolismo , Idade Gestacional , Humanos , Fígado/química , Fígado/embriologia , Fígado/enzimologia , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Defeitos do Tubo Neural/embriologia , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo , Gravidez , Vitamina B 12/análise
14.
Clin Dysmorphol ; 28(3): 137-141, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30789376

RESUMO

Rubinstein-Taybi syndrome (RSTS) is a rare dominant disorder with intellectual disability, postnatal growth deficiency, and multiple congenital anomalies. Approximately 50-70% of the patients have a mutation in the CREBBP gene (RSTS1) and 5-10% display an EP300 gene mutation (RSTS2). Craniospinal abnormalities such as microcranium, scoliosis, and lordosis are frequent findings in RSTS1, but malformations of the brain or spinal cord are seen only occasionally. Here, we report on a 3-year-old boy with facial abnormalities of RSTS, broad thumbs and halluces, developmental delay, autistic features, cerebellar underdevelopment, and a neural tube defect. Molecular diagnostic of the CREBBP and EP300 genes showed a heterozygous 17-bp deletion (c.5698_5714del AAGGCAGCAGGCCAGGT) in exon 31 of the EP300 gene. Findings underline that small (hypoplastic) cerebellum and neural tube defects belong to the phenotypic spectrum not only of RSTS1 but also of RSTS2. Based on the literature and this observation, we recommend that each individual with RSTS2 should be closely evaluated for neural axis and craniovertebral junction anomalies, and where appropriate, neuroimaging studies should be considered. Our frequency estimate of ~ 6% occult or overt neural tube defects in RSTS2 could represent an underestimate.


Assuntos
Síndrome de Rubinstein-Taybi/genética , Síndrome de Rubinstein-Taybi/fisiopatologia , Proteína de Ligação a CREB/genética , Proteína de Ligação a CREB/metabolismo , Cerebelo/anormalidades , Pré-Escolar , Proteína p300 Associada a E1A/genética , Proteína p300 Associada a E1A/metabolismo , Éxons , Mutação da Fase de Leitura , Estudos de Associação Genética , Testes Genéticos , Genoma Humano , Genótipo , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mutação , Defeitos do Tubo Neural/genética , Deleção de Sequência/genética
15.
Clin Epigenetics ; 11(1): 17, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30709423

RESUMO

BACKGROUND: Neural tube defects (NTDs) are complex abnormalities associated with gene-environment interactions. The underlying cause has not been determined. METHODS: Spinal cord tissues from cases with NTDs and healthy controls were collected. Methylation patterns between cases and normal individuals were compared using 450K Infinium Methylation BeadChip Illumina. DNA methylation analysis by pyrosequencing (PyroMark Q96) and mRNA and protein expression were analyzed using real-time quantitative PCR and Western blotting, respectively. Next-generation and Sanger sequencing were used to determine genetic variants in the target genes. RESULTS: Spinal cord tissues from cases with NTDs had more hypomethylated than hypermethylated genes. Further evaluation showed that the exon 1 region of TRIM4 was hypomethylated, and TRIM4 mRNA and protein levels were significantly increased in NTDs compared to controls. A rare missense variant (rs76665876) in TRIM4 was found in 3 of the 14 NTD cases but was not related to TRIM4 expression. TRIM4 mRNA levels were significantly increased in cases with hypomethylation and without the rs76665876 variant. CONCLUSION: These findings suggest that spinal cord tissues in cases with NTDs had a different genome-wide methylation pattern compared to controls. Abnormal methylation patterns in TRIM4 in immunity pathways might be involved in NTD pathogenesis. Genetic variants in TRIM4 genes only slightly contribute to the etiology of human NTDs.


Assuntos
Metilação de DNA , Defeitos do Tubo Neural/genética , Transativadores/genética , Proteínas com Motivo Tripartido/genética , Ubiquitina-Proteína Ligases/genética , Regulação para Cima , Sequenciamento Completo do Genoma/métodos , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Idade Gestacional , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mutação de Sentido Incorreto , Defeitos do Tubo Neural/metabolismo , Proteínas com Motivo Tripartido/metabolismo
16.
Clin Epigenetics ; 11(1): 13, 2019 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-30665459

RESUMO

BACKGROUND: Neural tube defects (NTDs) are common and severe congenital malformations. Pax3 is an essential gene for neural tube closure in mice but it is unknown whether altered expression or methylation of PAX3 contributes to human NTDs. We examined the potential role of hypermethylation of Pax3 in the development of NTDs by analyzing human NTD cases and a mouse model in which NTDs were induced by benzo[a]pyrene (BaP), a widely studied polycyclic aromatic hydrocarbon (PAH). METHODS: We extracted methylation information of PAX3 in neural tissues from array data of ten NTD cases and eight non-malformed controls. A validation study was then performed in a larger independent population comprising 73 NTD cases and 29 controls. Finally, we examined methylation patterns and expression of Pax3 in neural tissues from mouse embryos of dams exposed to BaP or BaP and vitamin E. RESULTS: Seven CpG sites in PAX3 were hypermethylated in NTD fetuses as compared to controls in the array data. In the validation phase, significantly higher methylation levels in the body region of PAX3 were observed in NTD cases than in controls (P = 0.003). And mean methylation intensity in the body region of PAX3 in fetal neural tissues was positively correlated with median concentrations of PAH in maternal serum. In the mouse model, BaP-induced NTDs were associated with hypermethylation of specific CpG sites within both the promoter and body region of Pax3. Supplementation with vitamin E via chow decreased the rate of NTDs, partly recovered the repressed total antioxidant capacity in mouse embryos exposed to BaP, and this was accompanied by the normalization of Pax3 methylation level and gene expression. CONCLUSION: Hypermethylation of Pax3 may play a role in the development of NTDs; DNA methylation aberration may be caused by exposure to BaP, with possible involvement of oxidative stress.


Assuntos
Metilação de DNA , Exposição Materna/efeitos adversos , Defeitos do Tubo Neural/genética , Fator de Transcrição PAX3/genética , Hidrocarbonetos Policíclicos Aromáticos/efeitos adversos , Animais , Estudos de Casos e Controles , Ilhas de CpG , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Idade Materna , Camundongos , Defeitos do Tubo Neural/induzido quimicamente , Defeitos do Tubo Neural/tratamento farmacológico , Gravidez , Regiões Promotoras Genéticas , Vitamina E/administração & dosagem , Vitamina E/farmacologia
17.
Medicine (Baltimore) ; 98(2): e13998, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30633186

RESUMO

RATIONALE: Hereditary hyperhomocysteinemia results from a polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene that reduces folate metabolism. Mutations in the MTHFR gene are common in parents who have given birth to children with neural tube defects (NTDs). Most research has focused on the risk for fetal NTDs in women with hyperhomocysteinemia and MTHFR gene mutations. Studies investigating the association between hyperhomocysteinemia, MTHFR gene mutations, and the risk for fetal NTDs in men are scarce. PATIENT CONCERNS: Here, we report on 3 men with hyperhomocysteinemia and the MTHFR C677T homozygous TT genotype that have reproductive histories of fetal NTDs. DIAGNOSIS: these 3 men were diagnosed as hyperhomocysteinemia and MTHFR C677T homozygous TT genotype. INTERVENTIONS: Three men received homocysteine-lowering therapy. OUTCOMES: The first man's wife became pregnant, and a healthy infant was spontaneously delivered at term, the other 2 men's wives are still not pregnant. LESSONS: Findings from this case reports and published literature imply that hereditary hyperhomocysteinemia in men affects sperm quality and sperm DNA methylation and causes epigenetic modifications that can result in fetal NTDs. We recommend monitoring homocysteine and folate levels in men before conception and supplementing with folate as needed, especially in men with a reproductive history of fetuses with neural tube or other birth defects.


Assuntos
Hiper-Homocisteinemia/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Defeitos do Tubo Neural/genética , Adulto , Humanos , Masculino , Mutação
18.
Hum Mol Genet ; 28(10): 1726-1737, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30689861

RESUMO

Mutations in IRF6, TFAP2A and GRHL3 cause orofacial clefting syndromes in humans. However, Tfap2a and Grhl3 are also required for neurulation in mice. Here, we found that homeostasis of Irf6 is also required for development of the neural tube and associated structures. Over-expression of Irf6 caused exencephaly, a rostral neural tube defect, through suppression of Tfap2a and Grhl3 expression. Conversely, loss of Irf6 function caused a curly tail and coincided with a reduction of Tfap2a and Grhl3 expression in tail tissues. To test whether Irf6 function in neurulation was conserved, we sequenced samples obtained from human cases of spina bifida and anencephaly. We found two likely disease-causing variants in two samples from patients with spina bifida. Overall, these data suggest that the Tfap2a-Irf6-Grhl3 genetic pathway is shared by two embryologically distinct morphogenetic events that previously were considered independent during mammalian development. In addition, these data suggest new candidates to delineate the genetic architecture of neural tube defects and new therapeutic targets to prevent this common birth defect.


Assuntos
Proteínas de Ligação a DNA/genética , Fatores Reguladores de Interferon/genética , Neurulação/genética , Fator de Transcrição AP-2/genética , Fatores de Transcrição/genética , Animais , Sequência Conservada/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Camundongos , Mutação , Tubo Neural/crescimento & desenvolvimento , Tubo Neural/patologia , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/patologia , Transdução de Sinais/genética , Disrafismo Espinal/genética , Disrafismo Espinal/patologia
19.
J Nutr ; 149(2): 295-303, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30689919

RESUMO

BACKGROUND: The risk of neural tube defect (NTD)-affected pregnancies is reduced with adequate folic acid intake during early pregnancy. However, NTDs have been observed among offspring of women with adequate folic acid intake. Some of these women are possibly not absorbing enough folic acid. Because lactase deficiency can lead to poor nutrient absorption, we hypothesized that lactase-deficient women will be at increased risk of having offspring with NTDs. OBJECTIVE: We examined the association between maternal rs4988235 (a lactase deficiency genetic marker) and NTDs in offspring. METHODS: We conducted a case-control study using data from the National Birth Defects Prevention Study, United States, 1997-2009, restricting to non-Hispanic white (NHW) and Hispanic women. Cases were women with an offspring with an NTD (n = 378 NHW, 207 Hispanic), and controls were women with an offspring without a birth defect (n = 461 NHW, 165 Hispanic). Analyses were conducted separately by race/ethnicity, using logistic regression. Women with the CC genotype were categorized as being lactase deficient. To assess potential effect modification, analyses were stratified by lactose intake, folic acid supplementation, dietary folate, and diet quality. RESULTS: Among NHW women, the odds of being lactase deficient were greater among cases compared with controls (OR: 1.37; 95% CI: 1.02, 1.82). Among Hispanic women, the odds of being lactase deficient were significantly lower among cases compared with controls (OR: 0.50, 95% CI: 0.33, 0.77). The association differed when stratified by lactose intake in NHW women (higher odds among women who consumed ≥12 g lactose/1000 kcal) and by dietary folate in Hispanic women (opposite direction of associations). The association did not differ when stratified by folic acid supplementation or diet quality. CONCLUSIONS: Our findings suggest that maternal lactase deficiency is associated with NTDs in offspring. However, we observed opposite directions of effect by race/ethnicity that could not be definitively explained.


Assuntos
Predisposição Genética para Doença , Lactase/genética , Defeitos do Tubo Neural/genética , Polimorfismo de Nucleotídeo Único , Adulto , Estudos de Casos e Controles , Ácido Fólico/administração & dosagem , Ácido Fólico/metabolismo , Deficiência de Ácido Fólico/complicações , Marcadores Genéticos , Genótipo , Hispano-Americanos , Humanos , Lactase/deficiência , Mães , Defeitos do Tubo Neural/enzimologia , Razão de Chances , Estados Unidos , Adulto Jovem
20.
Hum Mol Genet ; 28(2): 200-208, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30256984

RESUMO

Spina bifida (SB) is a complex disorder of failed neural tube closure during the first month of human gestation, with a suspected etiology involving multiple gene and environmental interactions. GPR161 is a ciliary G-protein coupled receptor that regulates Sonic Hedgehog (Shh) signaling. Gpr161 null and hypomorphic mutations cause neural tube defects (NTDs) in mouse models. Herein we show that several genes involved in Shh and Wnt signaling were differentially expressed in the Gpr161 null embryos using RNA-seq analysis. To determine whether there exists an association between GPR161 and SB in humans, we performed direct Sanger sequencing on the GPR161 gene in a cohort of 384 SB patients and 190 healthy controls. We identified six rare variants of GPR161 in six SB cases, of which two of the variants were novel and did not exist in any databases. Both of these variants were predicted to be damaging by SIFT and/or PolyPhen analysis. The novel GPR161 rare variants mislocalized to the primary cilia, dysregulated Shh and Wnt signaling and inhibited cell proliferation in vitro. Our results demonstrate that GPR161 mutations cause NTDs via dysregulation of Shh and Wnt signaling in mice, and novel rare variants of GPR161 can be risk factors for SB in humans.


Assuntos
Mutação , Receptores Acoplados a Proteínas-G/genética , Disrafismo Espinal/genética , Animais , Estudos de Casos e Controles , Perfilação da Expressão Gênica , Genes Dominantes , Proteínas Hedgehog/metabolismo , Humanos , Recém-Nascido , Camundongos , Camundongos Knockout , Células NIH 3T3 , Defeitos do Tubo Neural/genética , Fenótipo , Fatores de Risco , Transdução de Sinais , Disrafismo Espinal/embriologia , Proteínas Wnt/metabolismo
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