Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 140
Filtrar
1.
Nat Cell Biol ; 23(9): 967-977, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34497373

RESUMO

New coronary vessels are added to the heart around birth to support postnatal cardiac growth. Here we show that, in late fetal development, the embryonic coronary plexus at the inner myocardium of the ventricles expresses the angiogenic signalling factors VEGFR3 and DLL4 and generates new coronary vessels in neonates. Contrary to a previous model in which the formation of new coronary vessels in neonates from ventricular endocardial cells was proposed, we find that late fetal and neonatal ventricular endocardial cells lack angiogenic potential and do not contribute to new coronary vessels. Instead, we show using lineage-tracing as well as gain- and loss-of-function experiments that the pre-existing embryonic coronary plexus at the inner myocardium undergoes angiogenic expansion through the DLL4-NOTCH1 signalling pathway to vascularize the expanding myocardium. We also show that the pre-existing coronary plexus revascularizes the regenerating neonatal heart through a similar mechanism. These findings provide a different model of neonatal coronary angiogenesis and regeneration, potentially informing cardiovascular medicine.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Vasos Coronários/crescimento & desenvolvimento , Neovascularização Patológica/metabolismo , Neovascularização Fisiológica/fisiologia , Receptor Notch1/metabolismo , Animais , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Coração/crescimento & desenvolvimento , Ventrículos do Coração/metabolismo , Camundongos Transgênicos , Morfogênese/fisiologia , Miocárdio/metabolismo , Transdução de Sinais/fisiologia
2.
Nat Biomed Eng ; 5(8): 880-896, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34426676

RESUMO

Fibroblasts can be directly reprogrammed into cardiomyocytes, endothelial cells or smooth muscle cells. Here we report the reprogramming of mouse tail-tip fibroblasts simultaneously into cells resembling these three cell types using the microRNA mimic miR-208b-3p, ascorbic acid and bone morphogenetic protein 4, as well as the formation of tissue-like structures formed by the directly reprogrammed cells. Implantation of the formed cardiovascular tissue into the infarcted hearts of mice led to the migration of reprogrammed cells to the injured tissue, reducing regional cardiac strain and improving cardiac function. The migrated endothelial cells and smooth muscle cells contributed to vessel formation, and the migrated cardiomyocytes, which initially displayed immature characteristics, became mature over time and formed gap junctions with host cardiomyocytes. Direct reprogramming of somatic cells to make cardiac tissue may aid the development of applications in cell therapy, disease modelling and drug discovery for cardiovascular diseases.


Assuntos
Células Endoteliais/transplante , Coração/fisiologia , Infarto do Miocárdio/terapia , Miócitos de Músculo Liso/transplante , Regeneração , Animais , Ácido Ascórbico/farmacologia , Proteína Morfogenética Óssea 4/farmacologia , Reprogramação Celular/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Junções Comunicantes/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Miocárdio/citologia , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Neovascularização Fisiológica , Transcriptoma
4.
Bio Protoc ; 11(10): e4028, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34150935

RESUMO

Besides cardiomyocytes, the heart contains numerous interstitial cell types, including cardiac fibroblasts, endothelial cells, immune (myeloid and lymphoid) cells, and mural cells (pericytes and vascular smooth muscle cells), which play key roles in heart repair, regeneration, and disease. We recently published a comprehensive map of cardiac stromal cell heterogeneity and flux in healthy and infarcted hearts using single-cell RNA sequencing (scRNA-seq) ( Farbehi et al., 2019 ). Here, we describe the FACS (Fluorescent Activated Cell Sorting)-based method used in that study for isolation of two cardiac cell fractions from adult mouse ventricles: the total interstitial cell population (TIP; non-cardiomyocytes) and enriched (Pdgfra-GFP+) cardiac fibroblasts.

5.
Circ Genom Precis Med ; 14(2): e003144, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33629867

RESUMO

BACKGROUND: KCNMA1 encodes the α-subunit of the large-conductance Ca2+-activated K+ channel, KCa1.1, and lies within a linkage interval for atrial fibrillation (AF). Insights into the cardiac functions of KCa1.1 are limited, and KCNMA1 has not been investigated as an AF candidate gene. METHODS: The KCNMA1 gene was sequenced in 118 patients with familial AF. The role of KCa1.1 in normal cardiac structure and function was evaluated in humans, mice, zebrafish, and fly. A novel KCNMA1 variant was functionally characterized. RESULTS: A complex KCNMA1 variant was identified in 1 kindred with AF. To evaluate potential disease mechanisms, we first evaluated the distribution of KCa1.1 in normal hearts using immunostaining and immunogold electron microscopy. KCa1.1 was seen throughout the atria and ventricles in humans and mice, with strong expression in the sinus node. In an ex vivo murine sinoatrial node preparation, addition of the KCa1.1 antagonist, paxilline, blunted the increase in beating rate induced by adrenergic receptor stimulation. Knockdown of the KCa1.1 ortholog, kcnma1b, in zebrafish embryos resulted in sinus bradycardia with dilatation and reduced contraction of the atrium and ventricle. Genetic inactivation of the Drosophila KCa1.1 ortholog, slo, systemically or in adult stages, also slowed the heartbeat and produced fibrillatory cardiac contractions. Electrophysiological characterization of slo-deficient flies revealed bursts of action potentials, reflecting increased events of fibrillatory arrhythmias. Flies with cardiac-specific overexpression of the human KCNMA1 mutant also showed increased heart period and bursts of action potentials, similar to the KCa1.1 loss-of-function models. CONCLUSIONS: Our data point to a highly conserved role of KCa1.1 in sinus node function in humans, mice, zebrafish, and fly and suggest that KCa1.1 loss of function may predispose to AF.

6.
Nat Commun ; 12(1): 681, 2021 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514719

RESUMO

Endothelial cells play a critical role in the adaptation of tissues to injury. Tissue ischemia induced by infarction leads to profound changes in endothelial cell functions and can induce transition to a mesenchymal state. Here we explore the kinetics and individual cellular responses of endothelial cells after myocardial infarction by using single cell RNA sequencing. This study demonstrates a time dependent switch in endothelial cell proliferation and inflammation associated with transient changes in metabolic gene signatures. Trajectory analysis reveals that the majority of endothelial cells 3 to 7 days after myocardial infarction acquire a transient state, characterized by mesenchymal gene expression, which returns to baseline 14 days after injury. Lineage tracing, using the Cdh5-CreERT2;mT/mG mice followed by single cell RNA sequencing, confirms the transient mesenchymal transition and reveals additional hypoxic and inflammatory signatures of endothelial cells during early and late states after injury. These data suggest that endothelial cells undergo a transient mes-enchymal activation concomitant with a metabolic adaptation within the first days after myocardial infarction but do not acquire a long-term mesenchymal fate. This mesenchymal activation may facilitate endothelial cell migration and clonal expansion to regenerate the vascular network.


Assuntos
Endotélio/patologia , Transição Epitelial-Mesenquimal/genética , Infarto do Miocárdio/patologia , Miocárdio/patologia , Animais , Movimento Celular/genética , Plasticidade Celular/genética , Proliferação de Células/genética , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/patologia , Endotélio/citologia , Genes Reporter/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteínas Luminescentes/genética , Masculino , Camundongos , Camundongos Transgênicos , Miocárdio/citologia , RNA-Seq , Análise de Célula Única
7.
Genome Biol ; 21(1): 167, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641141

RESUMO

High-throughput single-cell RNA-seq (scRNA-seq) is a powerful tool for studying gene expression in single cells. Most current scRNA-seq bioinformatics tools focus on analysing overall expression levels, largely ignoring alternative mRNA isoform expression. We present a computational pipeline, Sierra, that readily detects differential transcript usage from data generated by commonly used polyA-captured scRNA-seq technology. We validate Sierra by comparing cardiac scRNA-seq cell types to bulk RNA-seq of matched populations, finding significant overlap in differential transcripts. Sierra detects differential transcript usage across human peripheral blood mononuclear cells and the Tabula Muris, and 3 'UTR shortening in cardiac fibroblasts. Sierra is available at https://github.com/VCCRI/Sierra .

8.
J Am Coll Cardiol ; 75(17): 2169-2188, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32354384

RESUMO

The extracellular matrix (ECM) is the noncellular component of tissues in the cardiovascular system and other organs throughout the body. It is formed of filamentous proteins, proteoglycans, and glycosaminoglycans, which extensively interact and whose structure and dynamics are modified by cross-linking, bridging proteins, and cleavage by matrix degrading enzymes. The ECM serves important structural and regulatory roles in establishing tissue architecture and cellular function. The ECM of the developing heart has unique properties created by its emerging contractile nature; similarly, ECM lining blood vessels is highly elastic in order to sustain the basal and pulsatile forces imposed on their walls throughout life. In this part 1 of a 4-part JACC Focus Seminar, we focus on the role, function, and basic biology of the ECM in both heart development and in the adult.


Assuntos
Cardiologia/educação , Sistema Cardiovascular/citologia , Sistema Cardiovascular/crescimento & desenvolvimento , Matriz Extracelular/fisiologia , Animais , Sistema Cardiovascular/metabolismo , Homeostase/fisiologia , Humanos , Proteoglicanas/metabolismo
9.
Cell Rep ; 30(2): 555-570.e7, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31940496

RESUMO

PDGFRα+ mesenchymal progenitor cells are associated with pathological fibro-adipogenic processes. Conversely, a beneficial role for these cells during homeostasis or in response to revascularization and regeneration stimuli is suggested, but remains to be defined. We studied the molecular profile and function of PDGFRα+ cells in order to understand the mechanisms underlying their role in fibrosis versus regeneration. We show that PDGFRα+ cells are essential for tissue revascularization and restructuring through injury-stimulated remodeling of stromal and vascular components, context-dependent clonal expansion, and ultimate removal of pro-fibrotic PDGFRα+-derived cells. Tissue ischemia modulates the PDGFRα+ phenotype toward cells capable of remodeling the extracellular matrix and inducing cell-cell and cell-matrix adhesion, likely favoring tissue repair. Conversely, pathological healing occurs if PDGFRα+-derived cells persist as terminally differentiated mesenchymal cells. These studies support a context-dependent "yin-yang" biology of tissue-resident mesenchymal progenitor cells, which possess an innate ability to limit injury expansion while also promoting fibrosis in an unfavorable environment.


Assuntos
Fibrose/metabolismo , Células-Tronco Mesenquimais/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Feminino , Fibrose/patologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Nus , Camundongos Transgênicos , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo
10.
Sci Transl Med ; 12(524)2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31894101

RESUMO

Therapies that target scar formation after myocardial infarction (MI) could prevent ensuing heart failure or death from ventricular arrhythmias. We have previously shown that recombinant human platelet-derived growth factor-AB (rhPDGF-AB) improves cardiac function in a rodent model of MI. To progress clinical translation, we evaluated rhPDGF-AB treatment in a clinically relevant porcine model of myocardial ischemia-reperfusion. Thirty-six pigs were randomized to sham procedure or balloon occlusion of the proximal left anterior descending coronary artery with 7-day intravenous infusion of rhPDGF-AB or vehicle. One month after MI, rhPDGF-AB improved survival by 40% compared with vehicle, and cardiac magnetic resonance imaging showed left ventricular (LV) ejection fraction improved by 11.5%, driven by reduced LV end-systolic volumes. Pressure volume loop analyses revealed improved myocardial contractility and energetics after rhPDGF-AB treatment with minimal effect on ventricular compliance. rhPDGF-AB enhanced angiogenesis and increased scar anisotropy (high fiber alignment) without affecting overall scar size or stiffness. rhPDGF-AB reduced inducible ventricular tachycardia by decreasing heterogeneity of the ventricular scar that provides a substrate for reentrant circuits. In summary, we demonstrated that rhPDGF-AB promotes post-MI cardiac wound repair by altering the mechanics of the infarct scar, resulting in robust cardiac functional improvement, decreased ventricular arrhythmias, and improved survival. Our findings suggest a strong translational potential for rhPDGF-AB as an adjunct to current MI treatment and possibly to modulate scar in other organs.


Assuntos
Cicatriz/patologia , Infarto do Miocárdio/patologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Animais , Arritmias Cardíacas/complicações , Arritmias Cardíacas/patologia , Arritmias Cardíacas/fisiopatologia , Arteríolas/efeitos dos fármacos , Arteríolas/patologia , Arteríolas/fisiopatologia , Cicatriz/complicações , Cicatriz/tratamento farmacológico , Cicatriz/fisiopatologia , Colágeno/metabolismo , Fibrose , Testes de Função Cardíaca/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/complicações , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Neovascularização Fisiológica/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/uso terapêutico , Proteínas Recombinantes/farmacologia , Análise de Sobrevida , Suínos , Cicatrização/efeitos dos fármacos
12.
Development ; 146(12)2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31118232

RESUMO

Recent advances in the generation of kidney organoids and the culture of primary nephron progenitors from mouse and human have been based on knowledge of the molecular basis of kidney development in mice. Although gene expression during kidney development has been intensely investigated, single cell profiling provides new opportunities to further subsect component cell types and the signalling networks at play. Here, we describe the generation and analysis of 6732 single cell transcriptomes from the fetal mouse kidney [embryonic day (E)18.5] and 7853 sorted nephron progenitor cells (E14.5). These datasets provide improved resolution of cell types and specific markers, including subdivision of the renal stroma and heterogeneity within the nephron progenitor population. Ligand-receptor interaction and pathway analysis reveals novel crosstalk between cellular compartments and associates new pathways with differentiation of nephron and ureteric epithelium cell types. We identify transcriptional congruence between the distal nephron and ureteric epithelium, showing that most markers previously used to identify ureteric epithelium are not specific. Together, this work improves our understanding of metanephric kidney development and provides a template to guide the regeneration of renal tissue.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Rim/embriologia , Receptor Cross-Talk , Análise de Célula Única/métodos , Algoritmos , Animais , Diferenciação Celular , Linhagem da Célula , Epitélio/embriologia , Rim/citologia , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Néfrons/embriologia , Organogênese , Transdução de Sinais , Células-Tronco/citologia , Transcriptoma , Ureter/embriologia
13.
Elife ; 82019 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-30912746

RESUMO

Besides cardiomyocytes (CM), the heart contains numerous interstitial cell types which play key roles in heart repair, regeneration and disease, including fibroblast, vascular and immune cells. However, a comprehensive understanding of this interactive cell community is lacking. We performed single-cell RNA-sequencing of the total non-CM fraction and enriched (Pdgfra-GFP+) fibroblast lineage cells from murine hearts at days 3 and 7 post-sham or myocardial infarction (MI) surgery. Clustering of >30,000 single cells identified >30 populations representing nine cell lineages, including a previously undescribed fibroblast lineage trajectory present in both sham and MI hearts leading to a uniquely activated cell state defined in part by a strong anti-WNT transcriptome signature. We also uncovered novel myofibroblast subtypes expressing either pro-fibrotic or anti-fibrotic signatures. Our data highlight non-linear dynamics in myeloid and fibroblast lineages after cardiac injury, and provide an entry point for deeper analysis of cardiac homeostasis, inflammation, fibrosis, repair and regeneration.


Assuntos
Linhagem da Célula , Infarto do Miocárdio/patologia , Regeneração , Cicatrização , Animais , Comunicação Celular , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Masculino , Camundongos , Análise de Célula Única
14.
Development ; 146(4)2019 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-30787001

RESUMO

Congenital heart disease (CHD) is the most common type of birth defect. In recent years, research has focussed on identifying the genetic causes of CHD. However, only a minority of CHD cases can be attributed to single gene mutations. In addition, studies have identified different environmental stressors that promote CHD, but the additive effect of genetic susceptibility and environmental factors is poorly understood. In this context, we have investigated the effects of short-term gestational hypoxia on mouse embryos genetically predisposed to heart defects. Exposure of mouse embryos heterozygous for Tbx1 or Fgfr1/Fgfr2 to hypoxia in utero increased the incidence and severity of heart defects while Nkx2-5+/- embryos died within 2 days of hypoxic exposure. We identified the molecular consequences of the interaction between Nkx2-5 and short-term gestational hypoxia, which suggest that reduced Nkx2-5 expression and a prolonged hypoxia-inducible factor 1α response together precipitate embryo death. Our study provides insight into the causes of embryo loss and variable penetrance of monogenic CHD, and raises the possibility that cases of foetal death and CHD in humans could be caused by similar gene-environment interactions.


Assuntos
Interação Gene-Ambiente , Cardiopatias Congênitas/genética , Coração/embriologia , Proteína Homeobox Nkx-2.5/genética , Proteínas de Homeodomínio/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Animais , Apoptose , Proliferação de Células , Embrião de Mamíferos/metabolismo , Feminino , Predisposição Genética para Doença , Coração/diagnóstico por imagem , Heterozigoto , Proteína Homeobox Nkx-2.5/fisiologia , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Oxigênio/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Proteínas com Domínio T/genética , Fatores de Tempo
15.
J Am Coll Cardiol ; 73(2): 190-209, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30654892

RESUMO

Endothelial to mesenchymal transition (EndMT) is a process whereby an endothelial cell undergoes a series of molecular events that lead to a change in phenotype toward a mesenchymal cell (e.g., myofibroblast, smooth muscle cell). EndMT plays a fundamental role during development, and mounting evidence indicates that EndMT is involved in adult cardiovascular diseases (CVDs), including atherosclerosis, pulmonary hypertension, valvular disease, and fibroelastosis. Therefore, the targeting of EndMT may hold therapeutic promise for treating CVD. However, the field faces a number of challenges, including the lack of a precise functional and molecular definition, a lack of understanding of the causative pathological role of EndMT in CVDs (versus being a "bystander-phenomenon"), and a lack of robust human data corroborating the extent and causality of EndMT in adult CVDs. Here, we review this emerging but exciting field, and propose a framework for its systematic advancement at the molecular and translational levels.


Assuntos
Doenças Cardiovasculares/etiologia , Transição Epitelial-Mesenquimal , Animais , Coração/embriologia , Humanos , Transdução de Sinais
16.
Genet Med ; 21(5): 1111-1120, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30293987

RESUMO

PURPOSE: Congenital heart disease (CHD) affects up to 1% of live births. However, a genetic diagnosis is not made in most cases. The purpose of this study was to assess the outcomes of genome sequencing (GS) of a heterogeneous cohort of CHD patients. METHODS: Ninety-seven families with probands born with CHD requiring surgical correction were recruited for genome sequencing. At minimum, a proband-parents trio was sequenced per family. GS data were analyzed via a two-tiered method: application of a high-confidence gene screen (hcCHD), and comprehensive analysis. Identified variants were assessed for pathogenicity using the American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP) guidelines. RESULTS: Clinically relevant genetic variants in known and emerging CHD genes were identified. The hcCHD screen identified a clinically actionable variant in 22% of families. Subsequent comprehensive analysis identified a clinically actionable variant in an additional 9% of families in genes with recent disease associations. Overall, this two-tiered approach provided a clinically relevant variant for 31% of families. CONCLUSIONS: Interrogating GS data using our two-tiered method allowed identification of variants with high clinical utility in a third of our heterogeneous cohort. However, association of emerging genes with CHD etiology, and development of novel technologies for variant assessment and interpretation, will increase diagnostic yield during future reassessment of our GS data.


Assuntos
Testes Genéticos/métodos , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/genética , Sequência de Bases/genética , Mapeamento Cromossômico/métodos , Estudos de Coortes , Exoma/genética , Família , Feminino , Predisposição Genética para Doença/genética , Variação Genética/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Mutação/genética , Pais , Análise de Sequência de DNA/métodos , Sequenciamento Completo do Genoma/métodos
18.
PLoS Genet ; 14(7): e1007502, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29979676

RESUMO

Left ventricular non-compaction (LVNC) is a rare cardiomyopathy associated with a hypertrabeculated phenotype and a large spectrum of symptoms. It is still unclear whether LVNC results from a defect of ventricular trabeculae development and the mechanistic basis that underlies the varying severity of this pathology is unknown. To investigate these issues, we inactivated the cardiac transcription factor Nkx2-5 in trabecular myocardium at different stages of trabecular morphogenesis using an inducible Cx40-creERT2 allele. Conditional deletion of Nkx2-5 at embryonic stages, during trabecular formation, provokes a severe hypertrabeculated phenotype associated with subendocardial fibrosis and Purkinje fiber hypoplasia. A milder phenotype was observed after Nkx2-5 deletion at fetal stages, during trabecular compaction. A longitudinal study of cardiac function in adult Nkx2-5 conditional mutant mice demonstrates that excessive trabeculation is associated with complex ventricular conduction defects, progressively leading to strain defects, and, in 50% of mutant mice, to heart failure. Progressive impaired cardiac function correlates with conduction and strain defects independently of the degree of hypertrabeculation. Transcriptomic analysis of molecular pathways reflects myocardial remodeling with a larger number of differentially expressed genes in the severe versus mild phenotype and identifies Six1 as being upregulated in hypertrabeculated hearts. Our results provide insights into the etiology of LVNC and link its pathogenicity with compromised trabecular development including compaction defects and ventricular conduction system hypoplasia.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Insuficiência Cardíaca/genética , Ventrículos do Coração/embriologia , Proteína Homeobox Nkx-2.5/metabolismo , Miocárdio Ventricular não Compactado Isolado/genética , Morfogênese/genética , Animais , Modelos Animais de Doenças , Feminino , Fibrose , Perfilação da Expressão Gênica , Ventrículos do Coração/patologia , Proteína Homeobox Nkx-2.5/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Miocárdio Ventricular não Compactado Isolado/complicações , Miocárdio Ventricular não Compactado Isolado/diagnóstico , Miocárdio Ventricular não Compactado Isolado/patologia , Camundongos , Camundongos Knockout , Miocárdio/metabolismo , Miocárdio/patologia , Ramos Subendocárdicos/patologia , Deleção de Sequência , Índice de Gravidade de Doença , Regulação para Cima
19.
Am Heart J ; 201: 33-39, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29910053

RESUMO

BACKGROUND: Up to 20% of children with congenital heart disease (CHD) undergoing cardiac surgery develop neurodevelopmental disabilities (NDD), with some studies reporting persistent impairment. Recent large-scale studies have demonstrated shared genetic mechanisms contributing to CHD and NDD. In this study, a targeted approach was applied to assess direct clinical applicability of this information. METHODS: A gene panel comprising 148 known CHD and/or NDD genes was used to sequence 15 patients with CHD + NDD, 15 patients with CHD, and 15 healthy controls. The number and types of variants between the 3 groups were compared using Poisson log-linear regression, and the SNP-set (Sequence) Kernel Association Test-Optimized was used to conduct single-gene and gene-pathway burden analyses. RESULTS: A significant increase in rare (minor allele frequency < 0.01) and novel variants was identified between the CHD + NDD cohort and controls, P < .001 and P = .001, respectively. There was also a significant increase in rare variants in the CHD cohort compared with controls (P = .04). Rare variant burden analyses implicated pathways associated with "neurotransmitters," "axon guidance," and those incorporating "RASopathy" genes in the development of NDD in CHD patients. CONCLUSIONS: These findings suggest that an increase in novel and rare variants in known CHD and/or NDD genes is associated with the development of NDD in patients with CHD. Furthermore, burden analyses point toward rare variant burden specifically in pathways related to brain development and function as contributors to NDD. Although promising variants and pathways were identified, further research, utilizing whole-genome approaches, is required prior to demonstrating clinical utility in this patient group.


Assuntos
DNA/genética , Cardiopatias Congênitas/genética , Transtornos do Neurodesenvolvimento/genética , Polimorfismo de Nucleotídeo Único , Procedimentos Cirúrgicos Cardíacos , Feminino , Seguimentos , Frequência do Gene , Cardiopatias Congênitas/cirurgia , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos
20.
Cell Rep ; 23(11): 3312-3326, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29898401

RESUMO

Application of advanced intravital imaging facilitates dynamic monitoring of pathway activity upon therapeutic inhibition. Here, we assess resistance to therapeutic inhibition of the PI3K pathway within the hypoxic microenvironment of pancreatic ductal adenocarcinoma (PDAC) and identify a phenomenon whereby pronounced hypoxia-induced resistance is observed for three clinically relevant inhibitors. To address this clinical problem, we have mapped tumor hypoxia by both immunofluorescence and phosphorescence lifetime imaging of oxygen-sensitive nanoparticles and demonstrate that these hypoxic regions move transiently around the tumor. To overlay this microenvironmental information with drug response, we applied a FRET biosensor for Akt activity, which is a key effector of the PI3K pathway. Performing dual intravital imaging of drug response in different tumor compartments, we demonstrate an improved drug response to a combination therapy using the dual mTORC1/2 inhibitor AZD2014 with the hypoxia-activated pro-drug TH-302.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Animais , Benzamidas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Quimioterapia Combinada , Feminino , Transferência Ressonante de Energia de Fluorescência , Humanos , Hipóxia , Microscopia Intravital/métodos , Camundongos , Camundongos Endogâmicos BALB C , Morfolinas/farmacologia , Morfolinas/uso terapêutico , Nanopartículas/química , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Mostardas de Fosforamida/farmacologia , Mostardas de Fosforamida/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pirimidinas , Transdução de Sinais/efeitos dos fármacos , Transplante Heterólogo , Microambiente Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...