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During adolescence, cannabis experimentation is common, and its association with inter-individual variations in brain maturation well studied. Cellular and molecular underpinnings of these system-level relationships are, however, unclear. We thus conducted a three-step study. First, we exposed adolescent male mice to Δ-9-tetrahydrocannabinol (THC) or a synthetic cannabinoid WIN 55,212-2 (WIN) and assessed differentially expressed genes (DEGs), spine numbers and dendritic complexity in their frontal cortex. Second, in human (male) adolescents, we examined group differences in cortical thickness in 34 brain regions, using magnetic resonance imaging, between those who experimented with cannabis before age 16 (n=140) and those who did not (n=327). Finally, we correlated spatially these group differences with gene expression of human homologs of the mouse-identified DEGs. The spatial expression of 13 THC-related human homologs of DEGs correlated with cannabis-related variations in cortical thickness, and virtual histology revealed co-expression patterns of these 13 genes with cell-specific markers of astrocytes, microglia and a type of pyramidal cells enriched in dendrite-regulating genes. Similarly, the spatial expression of 18 WIN-related human homologs of DEGs correlated with group differences in cortical thickness, and showed co-expression patterns with the same three cell types. Gene ontology analysis indicated that 37 THC-related human homologs are enriched in neuron-projection development, while 33 WIN-related homologs are enriched in processes associated with learning and memory. In mice, we observed spine loss and lower dendritic complexity in pyramidal cells of THC-exposed animals (vs. controls). Experimentation with cannabis during adolescence may influence cortical thickness by impacting glutamatergic synapses and dendritic arborization.Significance Statement Cells and molecular underpinning of cannabis-related variations in cortical thickness observed in adolescents are poorly understood. We assessed differences in gene expression in the frontal cortex of adolescent mice exposed (or not) to Δ-9-tetra-hydrocannabinol (THC) or WIN 55,212-2 (WIN). THC preferentially targeted glial cells, while WIN affected pyramidal neurons; both modified nuclear-coded subunits in mitochondrial respiratory complexes and excitatory synapse genes. In humans, we evaluated a spatial correlation between group differences in cortical thickness and the expression of human homologs of the cannabinoid-sensitive genes in mice. These genes co-expressed with those specific to astrocytes, microglia and a type of pyramidal cells enriched in dendrite-regulating genes. Experimentation with cannabis during adolescence may influence cortical thickness via synaptic processes and dendritic arborization.
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Ebstein anomaly (EA) is a rare, congenital cardiac defect of the tricuspid valve with a birth prevalence between 0.5 and 1 in 20,000 [1]. It is characterized by displacement of the tricuspid valve toward the apex of the right ventricle (RV) and "atrialization" of the RV (Fig. 57.1) [2]. EA accounts for about 0.5% of all congenital heart diseases (CHD) [2]. Depending on severity of the defect and due to heterogeneity of the disease, patient's presentation varies from severe heart failure symptoms and arrhythmia in neonatal life to asymptomatic adults.
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Anomalia de Ebstein , Valva Tricúspide , Anomalia de Ebstein/genética , Anomalia de Ebstein/fisiopatologia , Anomalia de Ebstein/diagnóstico por imagem , Humanos , Valva Tricúspide/anormalidades , Valva Tricúspide/fisiopatologia , Predisposição Genética para Doença , MutaçãoRESUMO
Ebstein's anomaly is a congenital malformation of the tricuspid valve characterized by abnormal attachment of the valve leaflets, resulting in varying degrees of valve dysfunction. The anatomic hallmarks of this entity are the downward displacement of the attachment of the septal and posterior leaflets of the tricuspid valve. Additional intracardiac malformations are common. From an embryological point of view, the cavity of the future right atrium does not have a direct orifice connected to the developing right ventricle. This chapter provides an overview of current insight into how this connection is formed and how malformations of the tricuspid valve arise from dysregulation of molecular and morphological events involved in this process. Furthermore, mouse models that show features of Ebstein's anomaly and the naturally occurring model of canine tricuspid valve malformation are described and compared to the human model. Although Ebstein's anomaly remains one of the least understood cardiac malformations to date, the studies summarized here provide, in aggregate, evidence for monogenic and oligogenic factors driving pathogenesis.
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Modelos Animais de Doenças , Anomalia de Ebstein , Valva Tricúspide , Anomalia de Ebstein/genética , Anomalia de Ebstein/patologia , Anomalia de Ebstein/fisiopatologia , Animais , Humanos , Cães , Camundongos , Valva Tricúspide/anormalidades , Valva Tricúspide/patologiaRESUMO
The roles of nitric oxide (NO) and endothelial NO synthase (eNOS) in the regulation of angiogenesis are well documented. However, the involvement of eNOS in the sprouting of endothelial tip-cells at the vascular front during sprouting angiogenesis remains poorly defined. In this study, we show that downregulation of eNOS markedly inhibits VEGF-stimulated migration of endothelial cells but increases their polarization, as evidenced by the reorientation of the Golgi in migrating monolayers and by the fewer filopodia on tip cells at ends of sprouts in endothelial cell spheroids. The effect of eNOS inhibition on EC polarization was prevented in Par3-depleted cells. Importantly, downregulation of eNOS increased the expression of polarity genes, such as PARD3B, PARD6A, PARD6B, PKCΖ, TJP3, and CRB1 in endothelial cells. In retinas of eNOS knockout mice, vascular development is retarded with decreased vessel density and vascular branching. Furthermore, tip cells at the extremities of the vascular front have a marked reduction in the number of filopodia per cell and are more oriented. In a model of oxygen-induced retinopathy (OIR), eNOS deficient mice are protected during the initial vaso-obliterative phase, have reduced pathological neovascularization, and retinal endothelial tip cells have fewer filopodia. Single-cell RNA sequencing of endothelial cells from OIR retinas revealed enrichment of genes related to cell polarity in the endothelial tip-cell subtype of eNOS deficient mice. These results indicate that inhibition of eNOS alters the polarity program of endothelial cells, which increases cell polarization, regulates sprouting angiogenesis and normalizes pathological neovascularization during retinopathy.
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Neovascularização Patológica , Neovascularização Fisiológica , Óxido Nítrico Sintase Tipo III/fisiologia , Retina/metabolismo , Neovascularização Retiniana , Vasos Retinianos , Animais , Bovinos , Linhagem Celular , Movimento Celular , Polaridade Celular , Células Endoteliais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Retina/citologia , Retina/patologia , Neovascularização Retiniana/metabolismo , Neovascularização Retiniana/patologia , Vasos Retinianos/citologia , Vasos Retinianos/patologiaRESUMO
Aim: Cardiovascular disease represents one of the main causes of secondary morbidity and mortality in patients with childhood cancer. Patients & methods: To further address this issue, we analyzed cardiovascular complications in relation to common and rare genetic variants derived through whole-exome sequencing from childhood acute lymphoblastic leukemia survivors (PETALE cohort). Results: Significant associations were detected among common variants in the TTN gene, left ventricular ejection fraction (p ≤ 0.0005), and fractional shortening (p ≤ 0.001). Rare variants enrichment in the NOS1, ABCG2 and NOD2 was observed in relation to left ventricular ejection fraction, and in NOD2 and ZNF267 genes in relation to fractional shortening. Following stratification according to risk groups, the modulatory effect of rare variants was additionally found in the CBR1, ABCC5 and AKR1C3 genes. None of the associations was replicated in St-Jude Lifetime Cohort Study. Conclusion: Further studies are needed to confirm whether the described genetic markers may be useful in identifying patients at increased risk of these complications.
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Sobreviventes de Câncer , Doenças Cardiovasculares/genética , Sequenciamento do Exoma/métodos , Variação Genética/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Adulto , Antineoplásicos/efeitos adversos , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Adulto JovemRESUMO
INTRODUCTION: Cardiovascular diseases are the main cause of treatment-related morbidity and mortality in childhood cancer patients. Anthracyclines, one of the most common chemotherapeutic agents in treatment regimens, are implicated in chemotherapy-induced cardiotoxicity. AREAS COVERED: This review describes the pharmacogenomic markers related to anthracycline-induced cardiotoxicity affecting childhood cancer patients. We also included a brief overview of the applicability of reported findings to the well-established PETALE cohort of childhood acute lymphoblastic leukemia survivors of the Sainte-Justine University Health Center (Canada). EXPERT OPINION: The wide variation in interindividual susceptibility to anthracycline-induced cardiotoxicity, along with a multitude of genetic variants detected through association studies, suggests that genetic contributions could be essential for the design of new individualized preventive approaches.
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Antraciclinas/efeitos adversos , Antineoplásicos/efeitos adversos , Cardiotoxicidade/etiologia , Animais , Antraciclinas/administração & dosagem , Antineoplásicos/administração & dosagem , Cardiotoxicidade/fisiopatologia , Cardiotoxicidade/prevenção & controle , Criança , Predisposição Genética para Doença , Humanos , Neoplasias/tratamento farmacológico , FarmacogenéticaRESUMO
BACKGROUND: Thoracic aortic aneurysms progressively enlarge and predispose to acute aortic dissections. Up to 25% of individuals with thoracic aortic disease harbor an underlying Mendelian pathogenic variant. An evidence-based strategy for selection of genes to test in hereditary thoracic aortic aneurysm and dissection (HTAAD) helps inform family screening and intervention to prevent life-threatening thoracic aortic events. OBJECTIVES: The purpose of this study was to accurately identify genes that predispose to HTAAD using the Clinical Genome Resource (ClinGen) framework. METHODS: We applied the semiquantitative ClinGen framework to assess presumed gene-disease relationships between 53 candidate genes and HTAAD. Genes were classified as causative for HTAAD if they were associated with isolated thoracic aortic disease and were clinically actionable, triggering routine aortic surveillance, intervention, and family cascade screening. All gene-disease assertions were evaluated by a pre-defined curator-expert pair and subsequently discussed with an expert panel. RESULTS: Genes were classified based on the strength of association with HTAAD into 5 categories: definitive (n = 9), strong (n = 2), moderate (n = 4), limited (n = 15), and no reported evidence (n = 23). They were further categorized by severity of associated aortic disease and risk of progression. Eleven genes in the definitive and strong groups were designated as "HTAAD genes" (category A). Eight genes were classified as unlikely to be progressive (category B) and 4 as low risk (category C). The remaining genes were recent genes with an uncertain classification or genes with no evidence of association with HTAAD. CONCLUSIONS: The ClinGen framework is useful to semiquantitatively assess the strength of gene-disease relationships for HTAAD. Gene categories resulting from the curation may inform clinical laboratories in the development, interpretation, and subsequent clinical implications of genetic testing for patients with aortic disease.
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Aneurisma da Aorta Torácica/diagnóstico , Aneurisma da Aorta Torácica/genética , Dissecção Aórtica/diagnóstico , Dissecção Aórtica/genética , Predisposição Genética para Doença/genética , Testes Genéticos/normas , Feminino , Testes Genéticos/métodos , Humanos , Masculino , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Childhood cancer survivorship issues represent an established public health challenge. Most late adverse effects (LAEs) have been demonstrated to be time and treatment dependent. The PETALE study is a multidisciplinary research project aiming to comprehensively characterize LAEs and identify associated predictive biomarkers in childhood acute lymphoblastic leukemia (cALL) survivors. METHODS: cALL survivors treated at Sainte-Justine University Health Center with Dana-Farber Cancer Institution-ALL protocols 87-01 through 2005-01 were eligible. During Phase I of the study, the participants underwent comprehensive clinical, biologic, and psychosocial investigation targeting metabolic syndrome, cardiotoxicity, bone morbidity, neurocognitive problems, and quality of life issues. Whole-exome sequencing was performed for all participants. Subjects identified with an extreme phenotype during Phase I were recalled for additional testing (Phase II). RESULTS: Phase I included 246 survivors (recall rate 71.9%). Of those, 85 participants completed Phase II (recall rate 88.5%). Survivors agreeing to participate in Phase I (n = 251) were similar to those who refused (n = 31) in terms of relapse risk profile, radiotherapy exposure, and age at the time of study. Participants, however, tended to be slightly older at diagnosis (6.1 vs. 4.7 years old, P = 0.08), with a higher proportion of female agreeing to participate compared with males (93.2 vs. 86.5%, P = 0.07). CONCLUSION: The PETALE study will contribute to comprehensively characterize clinical, psychosocial, biologic, and genomic features of cALL survivors using an integrated approach. Expected outcomes include LAE early detection biomarkers, long-term follow-up guidelines, and recommendations for physicians and health professionals.
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Biomarcadores Tumorais/metabolismo , Doenças Ósseas , Cardiopatias , Síndrome Metabólica , Transtornos Neurocognitivos , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Adolescente , Adulto , Doenças Ósseas/epidemiologia , Doenças Ósseas/etiologia , Doenças Ósseas/metabolismo , Criança , Pré-Escolar , Feminino , Cardiopatias/epidemiologia , Cardiopatias/etiologia , Cardiopatias/metabolismo , Humanos , Lactente , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/metabolismo , Transtornos Neurocognitivos/epidemiologia , Transtornos Neurocognitivos/etiologia , Transtornos Neurocognitivos/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , SobreviventesRESUMO
Genetic disturbances in folate metabolism may increase risk for congenital heart defects. We examined the association of heart defects with four polymorphisms in folate-related genes (methylenetetrahydrofolate reductase (MTHFR) c.677C.T, MTHFR c.1298A.C, methionine synthase reductase (MTRR) c.66A.G, and reduced folate carrier (SLC19A1) c.80A.G) in a case-control study of children (156 patients, 69 controls) and mothers of children with heart defects (181 patients, 65 controls), born before folic acid fortification. MTRR c.66A.G in children modified odds ratios for overall heart defects, specifically ventricular septal defect and aortic valve stenosis (p-value below 0.05). The 66GG and AG genotypes were associated with decreased odds ratios for heart defects (0.42, 95% confidence interval (0.18-0.97) and 0.39 (0.18-0.84), respectively). This overall association was driven by decreased risk for ventricular septal defect for 66GG and AG (odds ratio 0.32 (0.11-0.91) and 0.25 (0.09-0.65)) and decreased odds ratio for aortic valve stenosis for 66AG (0.27 (0.09-0.79)). The association of ventricular septal defect and 66AG remained significant after correction for multiple testing (p = 0.0044, multiple testing threshold p = 0.0125). Maternal MTHFR 1298AC genotype was associated with increased odds ratio for aortic valve stenosis (2.90 (1.22-6.86), p = 0.0157), but this association did not meet the higher multiple testing threshold. No association between MTHFR c.677C.T or SLC19A1 c.80A.G and heart defect risk was found. The influence of folate-related polymorphisms may be specific to certain types of heart defects; larger cohorts of mothers and children with distinct sub-classes are required to adequately address risk.
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Ferredoxina-NADP Redutase/genética , Ácido Fólico/metabolismo , Cardiopatias Congênitas/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Proteína Carregadora de Folato Reduzido/genética , Estenose da Valva Aórtica/congênito , Estenose da Valva Aórtica/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Comunicação Interventricular/genética , Humanos , Masculino , Razão de Chances , Fenótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: Copy number variations (CNVs) and polymorphisms (CNPs) have only recently gained the genetic community's attention. Conservative estimates have shown that CNVs and CNPs might affect more than 10% of the genome and that they may be at least as important as single nucleotide polymorphisms in assessing human variability. Widely used tools for CNP analysis have been implemented in Birdsuite and PLINK for the purpose of conducting genetic association studies based on the unpartitioned total number of CNP copies provided by the intensities from Affymetrix's Genome-Wide Human SNP Array. Here, we are interested in partitioning copy number variations and polymorphisms in extended pedigrees for the purpose of linkage analysis on familial data. RESULTS: We have developed CNGen, a new software for the partitioning of copy number polymorphism using the integrated genotypes from Birdsuite with the Affymetrix platform. The algorithm applied to familial trios or extended pedigrees can produce partitioned copy number genotypes with distinct parental alleles. We have validated the algorithm using simulations on a complex pedigree structure using frequencies calculated from a real dataset of 300 genotyped samples from 42 pedigrees segregating a congenital heart defect phenotype. CONCLUSIONS: CNGen is the first published software for the partitioning of copy number genotypes in pedigrees, making possible the use CNPs and CNVs for linkage analysis. It was implemented with the Python interpreter version 2.5.2. It was successfully tested on current Linux, Windows and Mac OS workstations.
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Variações do Número de Cópias de DNA , Genótipo , Linhagem , Dosagem de Genes , Variação Genética , Humanos , FenótipoRESUMO
Methylenetetrahydrofolate dehydrogenase)methenyltetrahydrofolate cyclohydrolase)formyltetrahydrofolate synthetase (MTHFD1) is a trifunctional enzyme that interconverts tetrahydrofolate (THF) derivatives for nucleotide synthesis. A common variant in MTHFD1, p.Arg653Gln (c.1958G>A), may increase the risk for neural tube defects (NTD). To examine the biological impact of this variant on MTHFD1 function, we measured enzyme activity and stability in vitro and assessed substrate flux in transfected mammalian cells. The purified Arg653Gln enzyme has normal substrate affinity but a 36% reduction in half)life at 42 degrees C. Thermolability is reduced by magnesium adenosine triphosphate and eliminated by the substrate analog folate pentaglutamate, suggesting that folate status may modulate impact of the variant. The mutation reduces the metabolic activity of MTHFD1 within cells: formate incorporation into DNA in murine Mthfd1 knockout cells transfected with Arg653Gln is reduced by 26%+/-7.7% (P<0.05), compared to cells transfected with wild)type protein, indicating a disruption of de novo purine synthesis. We assessed the impact of the variant on risk for congenital heart defects (CHD) in a cohort of Quebec children (158 cases, 110 controls) and mothers of children with heart defects (199 cases, 105 controls). The 653QQ genotype in children is associated with increased risk for heart defects (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.01-4.42), particularly Tetralogy of Fallot (OR, 3.60; 95% CI, 1.38-9.42) and aortic stenosis (OR, 3.13; 95% CI, 1.13-8.66). There was no effect of maternal genotype. Our results indicate that the Arg653Gln polymorphism decreases enzyme stability and increases risk for CHD. Further evaluation of this polymorphism in folate)related disorders and its potential interaction with folate status is warranted.
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Substituição de Aminoácidos , Predisposição Genética para Doença , Cardiopatias Congênitas/enzimologia , Cardiopatias Congênitas/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo , Mutação/genética , Adolescente , Animais , Estudos de Casos e Controles , Coenzimas , Inibidores Enzimáticos , Estabilidade Enzimática , Feminino , Formiato-Tetra-Hidrofolato Ligase/genética , Formiato-Tetra-Hidrofolato Ligase/isolamento & purificação , Formiato-Tetra-Hidrofolato Ligase/metabolismo , Frequência do Gene , Humanos , Cinética , Meteniltetra-Hidrofolato Cicloidrolase/genética , Meteniltetra-Hidrofolato Cicloidrolase/isolamento & purificação , Meteniltetra-Hidrofolato Cicloidrolase/metabolismo , Metilenotetra-Hidrofolato Desidrogenase (NADP)/isolamento & purificação , Camundongos , Antígenos de Histocompatibilidade Menor , Polimorfismo Genético , Homologia Estrutural de Proteína , Especificidade por Substrato , TemperaturaRESUMO
OBJECTIVES: Cardiovascular malformations (CVMs) are reported to be common (approximately 75%) in patients with deletion 22q11.2 (del22q11) syndrome. To better understand why deletions go unrecognized, we characterized the phenotype in deleted individuals in two large kindreds with particular emphasis on the presence or absence of CVM. STUDY DESIGN: After the diagnosis of del22q11 in two unrelated probands with CVM, we sequentially evaluated family members with clinical evaluation and cytogenetic analysis. RESULTS: Del22q11 was identified in 13 individuals; all exhibited characteristic dysmorphic facial features, but a CVM was present in only 6 of 13 (46%) individuals. CONCLUSIONS: We speculate that in the absence of CVM, diagnosis of del22q11 is hampered by a failure to recognize extracardiac features of the del22q11 syndrome spectrum. The data highlight the need for primary care physicians and specialists to familiarize themselves with the extracardiac stigmata of del22q11 to ensure timely diagnosis in all family members.