Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Med Genet ; 61(2): 176-181, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-37798098

RESUMO

BACKGROUND: Expanded genetic screening before conception or during prenatal care can provide a more comprehensive evaluation of heritable fetal diseases. This study aimed to provide a large cohort to evaluate the significance of expanded carrier screening and to consolidate the role of expanded genetic screening in prenatal care. METHODS: This multicentre, retrospective cohort study was conducted between 31 December 2019 and 21 July 2022. A screening panel containing 302 genes and next-generation sequencing were used for the evaluation. The patients were referred from obstetric clinics, infertility centres and medical centres. Genetic counsellors conducted consultation for at least 15 min before and after screening. RESULTS: A total of 1587 patients were screened, and 653 pairs were identified. Among the couples who underwent the screening, 62 (9.49%) had pathogenic variants detected on the same genes. In total, 212 pathogenic genes were identified in this study. A total of 1173 participants carried at least one mutated gene, with a positive screening rate of 73.91%. Among the pathogenic variants that were screened, the gene encoding gap junction beta-2 (GJB2) exhibited the highest prevalence, amounting to 19.85%. CONCLUSION: Next-generation sequencing carrier screening provided additional information that may alter prenatal obstetric care by 9.49%. Pan-ethnic genetic screening and counselling should be suggested for couples of fertile age.


Assuntos
Aconselhamento , Testes Genéticos , Gravidez , Feminino , Humanos , Triagem de Portadores Genéticos , Estudos Retrospectivos , Estudos Prospectivos
2.
Phys Rev Lett ; 132(5): 056204, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364165

RESUMO

One-dimensional graphene superlattice subjected to strong Kronig-Penney (KP) potential is promising for achieving the electron-lensing effect, while previous studies utilizing the modulated dielectric gates can only yield a moderate, spatially dispersed potential profile. Here, we realize high KP potential modulation of graphene via nanoscale ferroelectric domain gating. Graphene transistors are fabricated on PbZr_{0.2}Ti_{0.8}O_{3} back gates patterned with periodic, 100-200 nm wide stripe domains. Because of band reconstruction, the h-BN top gating induces satellite Dirac points in samples with current along the superlattice vector s[over ^], a feature absent in samples with current perpendicular to s[over ^]. The satellite Dirac point position scales with the superlattice period (L) as ∝L^{ß}, with ß=-1.18±0.06. These results can be well explained by the high KP potential scenario, with the Fermi velocity perpendicular to s[over ^] quenched to about 1% of that for pristine graphene. Our study presents a promising material platform for realizing electron supercollimation and investigating flat band phenomena.

3.
Nature ; 557(7705): 439-445, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29743679

RESUMO

In vertebrate hearts, the ventricular trabecular myocardium develops as a sponge-like network of cardiomyocytes that is critical for contraction and conduction, ventricular septation, papillary muscle formation and wall thickening through the process of compaction 1 . Defective trabeculation leads to embryonic lethality2-4 or non-compaction cardiomyopathy (NCC) 5 . There are divergent views on when and how trabeculation is initiated in different species. In zebrafish, trabecular cardiomyocytes extrude from compact myocardium 6 , whereas in chicks, chamber wall thickening occurs before overt trabeculation 7 . In mice, the onset of trabeculation has not been described, but is proposed to begin at embryonic day 9.0, when cardiomyocytes form radially oriented ribs 2 . Endocardium-myocardium communication is essential for trabeculation, and numerous signalling pathways have been identified, including Notch2,8 and Neuregulin (NRG) 4 . Late disruption of the Notch pathway causes NCC 5 . Whereas it has been shown that mutations in the extracellular matrix (ECM) genes Has2 and Vcan prevent the formation of trabeculae in mice9,10 and the matrix metalloprotease ADAMTS1 promotes trabecular termination 3 , the pathways involved in ECM dynamics and the molecular regulation of trabeculation during its early phases remain unexplored. Here we present a model of trabeculation in mice that integrates dynamic endocardial and myocardial cell behaviours and ECM remodelling, and reveal new epistatic relationships between the involved signalling pathways. NOTCH1 signalling promotes ECM degradation during the formation of endocardial projections that are critical for individualization of trabecular units, whereas NRG1 promotes myocardial ECM synthesis, which is necessary for trabecular rearrangement and growth. These systems interconnect through NRG1 control of Vegfa, but act antagonistically to establish trabecular architecture. These insights enabled the prediction of persistent ECM and cardiomyocyte growth in a mouse NCC model, providing new insights into the pathophysiology of congenital heart disease.


Assuntos
Coração/embriologia , Miocárdio/citologia , Miocárdio/metabolismo , Neuregulina-1/metabolismo , Organogênese , Receptor Notch1/metabolismo , Animais , Modelos Animais de Doenças , Endocárdio/citologia , Endocárdio/metabolismo , Matriz Extracelular/metabolismo , Cardiopatias/congênito , Cardiopatias/metabolismo , Camundongos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Neuregulina-1/genética , Receptor Notch1/genética , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo
4.
J Formos Med Assoc ; 122(8): 785-789, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36907791

RESUMO

BACKGROUND: The rate of induction of labour has increased over the decades and numerous medications are available in the market. This study compares the efficacy and safety between dinoprostone slow-release pessary (Propess) and dinoprostone tablet (Prostin) for labour induction at term in nulliparous women. METHODS: This was a prospective single-blind randomized controlled trial conducted in a tertiary medical centre in Taiwan from September 1, 2020 to February 28, 2021. We recruited nulliparous women at term with a singleton pregnancy, fetus in cephalic presentation, an unfavourable cervix, and the cervical length had been measured by transvaginal sonography three times during labour induction. The main outcomes are duration from induction of labour to vaginal delivery, vaginal delivery rate, maternal and neonatal complication rates. RESULTS: In both groups, Prostin and Propess, 30 pregnant women were enrolled. The Propess group had higher vaginal delivery rate but it did not meet statistically significant difference. The Prostin group had significantly higher rate of adding oxytocin for augmentation (p = 0.0002). No significant difference was observed in either labouring course, maternal or neonatal outcomes. The probability of vaginal delivery was independently related to the cervical length measured by transvaginal sonography 8 h after Prostin or Propess administration as well as neonatal birth weight. CONCLUSION: Both Prostin and Propess can be used as cervical ripening agents with similar efficacy and without significant morbidity. Propess administration was associated with higher vaginal delivery rate and less need to add oxytocin. Intrapartum measurement of cervical length is helpful in predicting successful vaginal delivery.


Assuntos
Dinoprostona , Ocitócicos , Recém-Nascido , Gravidez , Feminino , Humanos , Ocitocina , Estudos Prospectivos , Método Simples-Cego , Trabalho de Parto Induzido
5.
J Formos Med Assoc ; 121(9): 1798-1803, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35379575

RESUMO

BACKGROUND: Preterm premature rupture of membranes (PPROM) is one of the most common causes of preterm birth. Antibiotic treatment is recommended to prolong the pregnancy course and reduce fetal morbidity in women with PPROM. However, the guidelines for antibiotic selection are based on studies done years ago, mostly in Western countries, which may not reflect the geographic, temporal, and ethnic variation in microbial colonization and infection in other parts of the world. We aimed to understand whether the antibiotics recommended by the current guidelines were sufficient to eradicate the majority of pathogens involved. METHODS: This is a single-center retrospective study at a tertiary medical center in Taiwan with patients recruited from January 1, 2017, to December 31, 2019. All patient included had a confirmed diagnosis of PPROM. In this study, we aimed to investigate which broad-spectrum antibiotic was most suitable for PPROM cases in Taiwan. RESULTS: 133 women were included, and 121 women had positive culture results. Most of the pregnant women had one positive result (35.5%). The most common pathogen was Lactobacillus species (27.8%), followed by Streptococcus species (12.9%) and Staphylococcus species (12.09%). CONCLUSION: The most appropriate antibiotic therapy for PPROM was a combination of 1 g azithromycin given orally on admission plus a third-generation cephalosporin administered intravenously in the first 48 hours and followed by amoxicillin 500 mg per os for another five days. This recommended antibiotic regimen for women with PPROM needs further study under a randomized clinical trial with a larger study population to evaluate its efficacy.


Assuntos
Ruptura Prematura de Membranas Fetais , Nascimento Prematuro , Antibacterianos , Feminino , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos
6.
J Formos Med Assoc ; 120(8): 1635-1641, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33581963

RESUMO

PURPOSE: To evaluate the effectiveness of adding carbetocin to regular uterotonic agents for prevention of postpartum hemorrhage (PPH) after cesarean section for twin pregnancies. METHODS: This is a retrospective uncontrolled before-after study done in a tertiary center in Taiwan, 2010-2017. Women with twin pregnancies that underwent cesarean section were enrolled. The control group (n = 114) received oxytocin infusion and direct uterine injection. In addition to these, the study group (n = 127) received 100ug of intravenous carbetocin. Primary endpoint was the change in hemoglobin. Secondary endpoints included risk of PPH and undiagnosed PPH (Hb dropped more than 2 g/dL), blood loss, the need for additional uterotonic maneuvers, and blood transfusion. Hemodynamic changes were also investigated. RESULTS: After adjusting for confounding factors, the change in Hb (0.35 g/dL, 95% CI: -0.03∼0.74) and incidence of PPH (OR 0.30, 95% CI: 0.03∼3.28) were comparable in both groups. However, women with undiagnosed PPH decreased (OR 0.43, 95% CI:0.22∼0.85). Total blood loss in 24 h after delivery also decreased (-40.33 mL, 95%CI: -80.32∼ -0.34). The use of extra uterotonic medications and the need for blood transfusion did not differ. The systolic blood pressure 4 h after childbirth was higher in the carbetocin group (6.71, 95% CI: 2.27∼11.15). CONCLUSION: The use of carbetocin in addition to regular uterotonic agents decreased total blood loss and undiagnosed PPH. Also, systolic blood pressure 4 h after childbirth is higher in the carbetocin group. There was no significant difference in hemoglobin change and risk of PPH.


Assuntos
Ocitócicos , Ocitocina , Cesárea , Estudos Controlados Antes e Depois , Feminino , Humanos , Ocitócicos/uso terapêutico , Ocitocina/análogos & derivados , Gravidez , Gravidez de Gêmeos , Estudos Retrospectivos , Taiwan
7.
J Biol Chem ; 294(52): 19877-19888, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31712309

RESUMO

Bone morphogenetic protein 10 (BMP10) is a cardiac peptide growth factor belonging to the transforming growth factor ß superfamily that critically controls cardiovascular development, growth, and maturation. It has been shown that BMP10 elicits its intracellular signaling through a receptor complex of activin receptor-like kinase 1 with morphogenetic protein receptor type II or activin receptor type 2A. Previously, we generated and characterized a transgenic mouse line expressing BMP10 from the α-myosin heavy chain gene promoter and found that these mice have normal cardiac hypertrophic responses to both physiological and pathological stimuli. In this study, we report that these transgenic mice exhibit significantly reduced levels of cardiomyocyte apoptosis and cardiac fibrosis in response to a prolonged administration of the ß-adrenoreceptor agonist isoproterenol. We further confirmed this cardioprotective function with a newly generated conditional Bmp10 transgenic mouse line, in which Bmp10 was activated in adult hearts by tamoxifen. Moreover, the intraperitoneal administration of recombinant human BMP10 was found to effectively protect hearts from injury, suggesting potential therapeutic utility of using BMP10 to prevent heart failure. Gene profiling and biochemical analyses indicated that BMP10 activates the SMAD-mediated canonical pathway and, unexpectedly, also the signal transducer and activator of transcription 3 (STAT3)-mediated signaling pathway both in vivo and in vitro Additional findings further supported the notion that BMP10's cardioprotective function likely is due to its dual activation of SMAD- and STAT3-regulated signaling pathways, promoting cardiomyocyte survival and suppressing cardiac fibrosis.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Fator de Transcrição STAT3/metabolismo , Proteínas Smad/metabolismo , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Animais , Apoptose/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/genética , Matriz Extracelular/metabolismo , Coração/efeitos dos fármacos , Humanos , Isoproterenol/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Transgênicos , Miocárdio/metabolismo , Miocárdio/patologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Fator de Transcrição STAT3/deficiência , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos dos fármacos
8.
J Biol Chem ; 293(47): 18218-18229, 2018 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-30262665

RESUMO

Protein phosphatase 5 (PP5), a serine/threonine phosphatase, has a wide range of biological functions and exhibits elevated expression in tumor cells. We previously reported that pp5-deficient mice have altered ataxia-telangiectasia mutated (ATM)-mediated signaling and function. However, this regulation was likely indirect, as ATM is not a known PP5 substrate. In the current study, we found that pp5-deficient mice are hypersensitive to genotoxic stress. This hypersensitivity was associated with the marked up-regulation of the tumor suppressor tumor protein p53 and its downstream targets cyclin-dependent kinase inhibitor 1A (p21), MDM2 proto-oncogene (MDM2), and phosphatase and tensin homolog (PTEN) in pp5-deficient tissues and cells. These observations suggested that PP5 plays a role in regulating p53 stability and function. Experiments conducted with p53+/-pp5+/- or p53+/-pp5-/- mice revealed that complete loss of PP5 reduces tumorigenesis in the p53+/- mice. Biochemical analyses further revealed that PP5 directly interacts with and dephosphorylates p53 at multiple serine/threonine residues, resulting in inhibition of p53-mediated transcriptional activity. Interestingly, PP5 expression was significantly up-regulated in p53-deficient cells, and further analysis of pp5 promoter activity revealed that p53 strongly represses PP5 transcription. Our results suggest a reciprocal regulatory interplay between PP5 and p53, providing an important feedback mechanism for the cellular response to genotoxic stress.


Assuntos
Proteínas Nucleares/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Motivos de Aminoácidos , Animais , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dano ao DNA , Regulação para Baixo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Nucleares/química , Proteínas Nucleares/genética , Fosfoproteínas Fosfatases/química , Fosfoproteínas Fosfatases/genética , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genética
9.
Am J Physiol Heart Circ Physiol ; 316(2): H371-H379, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30499712

RESUMO

Cardiomyocyte-restricted overexpression of FK506-binding protein 12 transgenic (αMyHC-FKBP12) mice develop spontaneous atrial fibrillation (AF). The aim of the present study is to explore the mechanisms underlying the occurrence of AF in αMyHC-FKBP12 mice. Spontaneous AF was documented by telemetry in vivo and Langendorff-perfused hearts of αMyHC-FKBP12 and littermate control mice in vitro. Atrial conduction velocity was evaluated by optical mapping. The patch-clamp technique was applied to determine the potentially altered electrophysiology in atrial myocytes. Channel protein expression levels were evaluated by Western blot analyses. Spontaneous AF was recorded in four of seven αMyHC-FKBP12 mice but in none of eight nontransgenic (NTG) controls. Atrial conduction velocity was significantly reduced in αMyHC-FKBP12 hearts compared with NTG hearts. Interestingly, the mean action potential duration at 50% but not 90% was significantly prolonged in αMyHC-FKBP12 atrial myocytes compared with their NTG counterparts. Consistent with decreased conduction velocity, average peak Na+ current ( INa) density was dramatically reduced and the INa inactivation curve was shifted by approximately +7 mV in αMyHC-FKBP12 atrial myocytes, whereas the activation and recovery curves were unaltered. The Nav1.5 expression level was significantly reduced in αMyHC-FKBP12 atria. Furthermore, we found increases in atrial Cav1.2 protein levels and peak L-type Ca2+ current density and increased levels of fibrosis in αMyHC-FKBP12 atria. In summary, cardiomyocyte-restricted overexpression of FKBP12 reduces the atrial Nav1.5 expression level and mean peak INa, which is associated with increased peak L-type Ca2+ current and interstitial fibrosis in atria. The combined electrophysiological and structural changes facilitated the development of local conduction block and altered action potential duration and spontaneous AF. NEW & NOTEWORTHY This study addresses a long-standing riddle regarding the role of FK506-binding protein 12 in cardiac physiology. The work provides further evidence that FK506-binding protein 12 is a critical component for regulating voltage-gated sodium current and in so doing has an important role in arrhythmogenic physiology, such as atrial fibrillation.


Assuntos
Fibrilação Atrial/genética , Proteína 1A de Ligação a Tacrolimo/metabolismo , Potenciais de Ação , Animais , Fibrilação Atrial/metabolismo , Fibrilação Atrial/fisiopatologia , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Células Cultivadas , Átrios do Coração/citologia , Átrios do Coração/metabolismo , Átrios do Coração/fisiopatologia , Camundongos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Proteína 1A de Ligação a Tacrolimo/genética
10.
Pediatr Cardiol ; 39(6): 1099-1106, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29766225

RESUMO

Ventricular trabeculation and compaction are two essential morphogenetic events for generating a functionally competent ventricular wall. A significant reduction in trabeculation is usually associated with hypoplastic wall and ventricular compact zone deficiencies, which commonly leads to embryonic heart failure and early embryonic lethality. In contrast, the arrest of ventricular wall compaction (noncompaction) is believed to be causative to the left ventricular noncompaction (LVNC), a genetically heterogeneous disorder and the third most common cardiomyopathy among pediatric patients. After critically reviewing recent findings from genetically engineered mouse models, we suggest a model which proposes that defects in myofibrillogenesis and polarization in trabecular cardiomyocytes underly the common pathogenic mechanism for ventricular noncompaction.


Assuntos
Ventrículos do Coração/embriologia , Miocárdio Ventricular não Compactado Isolado/etiologia , Modelos Cardiovasculares , Animais , Cardiomiopatias/fisiopatologia , Proliferação de Células , Insuficiência Cardíaca/etiologia , Humanos , Miocárdio Ventricular não Compactado Isolado/genética , Camundongos , Miócitos Cardíacos/citologia
11.
Circulation ; 133(1): 48-61, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26628621

RESUMO

BACKGROUND: ß-Adrenergic receptors (ßARs) play paradoxical roles in the heart. On one hand, ßARs augment cardiac performance to fulfill the physiological demands, but on the other hand, prolonged activations of ßARs exert deleterious effects that result in heart failure. The signal transducer and activator of transcription 3 (STAT3) plays a dynamic role in integrating multiple cytokine signaling pathways in a number of tissues. Altered activation of STAT3 has been observed in failing hearts in both human patients and animal models. Our objective is to determine the potential regulatory roles of STAT3 in cardiac ßAR-mediated signaling and function. METHODS AND RESULTS: We observed that STAT3 can be directly activated in cardiomyocytes by ß-adrenergic agonists. To follow up this finding, we analyzed ßAR function in cardiomyocyte-restricted STAT3 knockouts and discovered that the conditional loss of STAT3 in cardiomyocytes markedly reduced the cardiac contractile response to acute ßAR stimulation, and caused disengagement of calcium coupling and muscle contraction. Under chronic ß-adrenergic stimulation, Stat3cKO hearts exhibited pronounced cardiomyocyte hypertrophy, cell death, and subsequent cardiac fibrosis. Biochemical and genetic data supported that Gαs and Src kinases are required for ßAR-mediated activation of STAT3. Finally, we demonstrated that STAT3 transcriptionally regulates several key components of ßAR pathway, including ß1AR, protein kinase A, and T-type Ca(2+) channels. CONCLUSIONS: Our data demonstrate for the first time that STAT3 has a fundamental role in ßAR signaling and functions in the heart. STAT3 serves as a critical transcriptional regulator for ßAR-mediated cardiac stress adaption, pathological remodeling, and heart failure.


Assuntos
Coração/fisiologia , Receptores Adrenérgicos beta/fisiologia , Fator de Transcrição STAT3/fisiologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Linhagem Celular , Coração/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Técnicas de Cultura de Órgãos
12.
Development ; 140(9): 1946-57, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23571217

RESUMO

Trabeculation and compaction of the embryonic myocardium are morphogenetic events crucial for the formation and function of the ventricular walls. Fkbp1a (FKBP12) is a ubiquitously expressed cis-trans peptidyl-prolyl isomerase. Fkbp1a-deficient mice develop ventricular hypertrabeculation and noncompaction. To determine the physiological function of Fkbp1a in regulating the intercellular and intracellular signaling pathways involved in ventricular trabeculation and compaction, we generated a series of Fkbp1a conditional knockouts. Surprisingly, cardiomyocyte-restricted ablation of Fkbp1a did not give rise to the ventricular developmental defect, whereas endothelial cell-restricted ablation of Fkbp1a recapitulated the ventricular hypertrabeculation and noncompaction observed in Fkbp1a systemically deficient mice, suggesting an important contribution of Fkbp1a within the developing endocardia in regulating the morphogenesis of ventricular trabeculation and compaction. Further analysis demonstrated that Fkbp1a is a novel negative modulator of activated Notch1. Activated Notch1 (N1ICD) was significantly upregulated in Fkbp1a-ablated endothelial cells in vivo and in vitro. Overexpression of Fkbp1a significantly reduced the stability of N1ICD and direct inhibition of Notch signaling significantly reduced hypertrabeculation in Fkbp1a-deficient mice. Our findings suggest that Fkbp1a-mediated regulation of Notch1 plays an important role in intercellular communication between endocardium and myocardium, which is crucial in controlling the formation of the ventricular walls.


Assuntos
Endocárdio/metabolismo , Ventrículos do Coração/patologia , Miocárdio/metabolismo , Receptor Notch1/metabolismo , Proteínas de Ligação a Tacrolimo/metabolismo , Animais , Linhagem da Célula , Células Cultivadas , Embrião de Mamíferos/embriologia , Embrião de Mamíferos/metabolismo , Embrião de Mamíferos/patologia , Desenvolvimento Embrionário , Endocárdio/embriologia , Endocárdio/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Ventrículos do Coração/embriologia , Ventrículos do Coração/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout/embriologia , Camundongos Knockout/metabolismo , Miocárdio/patologia , Crista Neural/metabolismo , Crista Neural/patologia , Fenótipo , Receptor Notch1/genética , Transdução de Sinais , Proteínas de Ligação a Tacrolimo/genética , Transfecção
13.
Proc Natl Acad Sci U S A ; 110(29): 11887-92, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23812757

RESUMO

Many important signaling pathways rely on multiple ligands. It is unclear if this is a mechanism of safeguard via redundancy or if it serves other functional purposes. In this study, we report unique insight into this question by studying the activin receptor-like kinase 1 (ALK1) pathway. Despite its functional importance in vascular development, the physiological ligand or ligands for ALK1 remain to be determined. Using conventional knockout and specific antibodies against bone morphogenetic protein 9 (BMP9) or BMP10, we showed that BMP9 and BMP10 are the physiological, functionally equivalent ligands of ALK1 in vascular development. Timing of expression dictates the in vivo requisite role of each ligand, and concurrent expression results in redundancy. We generated mice (Bmp10(9/9)) in which the coding sequence of Bmp9 replaces that of Bmp10. Surprisingly, analysis of Bmp10(9/9) mice demonstrated that BMP10 has an exclusive function in cardiac development, which cannot be substituted by BMP9. Our study reveals context-dependent significance in having multiple ligands in a signaling pathway.


Assuntos
Receptores de Ativinas Tipo I/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Sistema Cardiovascular/embriologia , Sistema Cardiovascular/crescimento & desenvolvimento , Fator 2 de Diferenciação de Crescimento/metabolismo , Transdução de Sinais/fisiologia , Receptores de Activinas Tipo II , Animais , Anticorpos Neutralizantes , Proteínas Morfogenéticas Ósseas/genética , Sistema Cardiovascular/metabolismo , Técnicas de Introdução de Genes , Fator 2 de Diferenciação de Crescimento/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Hibridização In Situ , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia de Fluorescência , Vasos Retinianos/crescimento & desenvolvimento , Vasos Retinianos/metabolismo
14.
J Biol Chem ; 289(6): 3799-810, 2014 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-24371141

RESUMO

The Phosphatase of Regenerating Liver (PRL) proteins promote cell signaling and are oncogenic when overexpressed. However, our understanding of PRL function came primarily from studies with cultured cell lines aberrantly or ectopically expressing PRLs. To define the physiological roles of the PRLs, we generated PRL2 knock-out mice to study the effects of PRL deletion in a genetically controlled, organismal model. PRL2-deficient male mice exhibit testicular hypotrophy and impaired spermatogenesis, leading to decreased reproductive capacity. Mechanistically, PRL2 deficiency results in elevated PTEN level in the testis, which attenuates the Kit-PI3K-Akt pathway, resulting in increased germ cell apoptosis. Conversely, increased PRL2 expression in GC-1 cells reduces PTEN level and promotes Akt activation. Our analyses of PRL2-deficient animals suggest that PRL2 is required for spermatogenesis during testis development. The study also reveals that PRL2 promotes Kit-mediated PI3K/Akt signaling by reducing the level of PTEN that normally antagonizes the pathway. Given the strong cancer susceptibility to subtle variations in PTEN level, the ability of PRL2 to repress PTEN expression qualifies it as an oncogene and a novel target for developing anti-cancer agents.


Assuntos
Proteínas Imediatamente Precoces/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Transdução de Sinais/fisiologia , Animais , Apoptose/fisiologia , Feminino , Células Germinativas/citologia , Células Germinativas/metabolismo , Proteínas Imediatamente Precoces/genética , Masculino , Camundongos , Camundongos Knockout , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Tirosina Fosfatases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-kit/genética , Espermatogênese/fisiologia , Testículo/citologia , Testículo/metabolismo
15.
Dev Biol ; 373(1): 53-63, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23063798

RESUMO

MYCN is a highly conserved transcription factor with multifaceted roles in development and disease. Mutations in MYCN are associated with Feingold syndrome, a developmental disorder characterized in part by congenital heart defects. Mouse models have helped elucidate MYCN functions; however its cardiac-specific roles during development remain unclear. We employed a Cre/loxp strategy to uncover the specific activities of MYCN in the developing mouse myocardium. Myocardial deletion of Mycn resulted in a thin-myocardial wall defect with dramatically reduced trabeculation. The mutant heart defects strongly resemble the phenotype caused by disruption of BMP10 and Neuregulin-1 (NRG1) signaling pathways, two central mediators of myocardial wall development. Our further examination showed that expression of MYCN is regulated by both BMP and NRG1 signaling. The thin-wall defect in mutant hearts is caused by a reduction in both cell proliferation and cell size. MYCN promotes cardiomyocyte proliferation through regulating expression of cell cycle regulators (including CCND1, CCND2, and ID2) and promotes cardiomyocyte growth through regulating expression of p70S6K. In addition, expression of multiple sarcomere proteins is altered in Mycn myocardial-inactivation embryos, indicating its essential role for proper cardiomyocyte differentiation. In summary, Mycn acts downstream of BMP and NRG1 cardiogenic signaling pathways to promote normal myocardial wall morphogenesis.


Assuntos
Regulação da Expressão Gênica/fisiologia , Ventrículos do Coração/embriologia , Morfogênese/fisiologia , Miocárdio/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Primers do DNA/genética , Imunofluorescência , Regulação da Expressão Gênica/genética , Genótipo , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Morfogênese/genética , Proteína Proto-Oncogênica N-Myc , Neuregulina-1/metabolismo , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
16.
Development ; 138(2): 303-15, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21177343

RESUMO

Dishevelled-associated activator of morphogenesis 1 (Daam1), a member of the formin protein family, plays an important role in regulating the actin cytoskeleton via mediation of linear actin assembly. Previous functional studies of Daam1 in lower species suggest its essential role in Drosophila trachea formation and Xenopus gastrulation. However, its in vivo physiological function in mammalian systems is largely unknown. We have generated Daam1-deficient mice via gene-trap technology and found that Daam1 is highly expressed in developing murine organs, including the heart. Daam1-deficient mice exhibit embryonic and neonatal lethality and suffer multiple cardiac defects, including ventricular noncompaction, double outlet right ventricles and ventricular septal defects. In vivo genetic rescue experiments further confirm that the lethality of Daam1-deficient mice results from the inherent cardiac abnormalities. In-depth analyses have revealed that Daam1 is important for regulating filamentous actin assembly and organization, and consequently for cytoskeletal function in cardiomyocytes, which contributes to proper heart morphogenesis. Daam1 is also found to be important for proper cytoskeletal architecture and functionalities in embryonic fibroblasts. Biochemical analyses indicate that Daam1 does not regulate cytoskeletal organization through RhoA, Rac1 or Cdc42. Our study highlights a crucial role for Daam1 in regulating the actin cytoskeleton and tissue morphogenesis.


Assuntos
Coração Fetal/embriologia , Proteínas dos Microfilamentos/fisiologia , Proteínas rho de Ligação ao GTP/fisiologia , Actinas/metabolismo , Animais , Apoptose , Sequência de Bases , Adesão Celular , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Primers do DNA/genética , Feminino , Coração Fetal/anormalidades , Coração Fetal/citologia , Coração Fetal/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Cardiopatias Congênitas/embriologia , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Morfogênese/genética , Morfogênese/fisiologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fenótipo , Gravidez , Proteínas rho de Ligação ao GTP/deficiência , Proteínas rho de Ligação ao GTP/genética
17.
Front Vet Sci ; 11: 1366759, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38500606

RESUMO

Granulosa cells (GCs) are essential for follicular development, and long non-coding RNAs (LncRNAs) are known to support the maintenance of this process and hormone synthesis in mammals. Nevertheless, the regulatory roles of these lncRNAs within sheep follicular GCs remain largely unexplored. This study delved into the influence of a Loc105611671, on the proliferation and steroid hormone synthesis of sheep ovarian GCs and the associated target genes in vitro. Cell Counting Kit-8 (CCK-8) gain-of-function experiments indicated that overexpression of Loc105611671 significantly boosted GCs proliferation, along with estrogen (E2) and progesterone (P4) levels. Further mechanistic scrutiny revealed that Loc105611671 is primarily localized within the cytoplasm of ovarian granulosa cells and engages in molecular interplay with CDC42. This interaction results in the upregulation of CDC42 protein expression. Moreover, it was discerned that increased CDC42 levels contribute to augmented proliferation of follicular granulosa cells and the secretion of E2 and P4. Experiments involving co-transfection elucidated that the concurrent overexpression of CDC42 and Loc105611671 acted synergistically to potentiate these effects. These findings provide insights into the molecular underpinnings of fecundity in ovine species and may inform future strategies for enhancing reproductive outcomes.

18.
Dermatitis ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38563786

RESUMO

Background: Mutations in filaggrin (FLG), the gene that codes for the skin barrier protein, have been shown to be associated with atopic dermatitis (AD). Objective: The objectives of this study were to determine the effects of genetic counseling and parental education on infants at a high risk of AD. Methods: We enrolled 7521 newborns in Taiwan from January 1, 2016, to March 30, 2020, and all of them received genetic testing encompassing 20 known FLG mutations. The genetic counseling and AD prevention and care team consisted of pediatricians, dermatologists, social workers, and genetic counselors. The counseling was arranged for at least 30 minutes within 45 days after delivery. Results: A total of 2963 high-risk infants (39.4%) were identified. Homozygous c.1432C>T was the most commonly identified mutation. A total of 418 neonates' parents were stratified into counseling and noncounseling groups, where the effect of parental education was evaluated. The genetically stratified parental education program was effective in preventing AD development by 63.3% in high-risk infants before 12 months of life (P < 0.0001). Conclusion: Genetic stratification and parental education are effective in preventing the development of AD in high-risk infants before 12 months of life.

19.
J Biol Chem ; 287(38): 32172-9, 2012 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-22791713

RESUMO

The PRL (phosphatase of regenerating liver) phosphatases are implicated in the control of cell proliferation and invasion. Aberrant PRL expression is associated with progression and metastasis of multiple cancers. However, the specific in vivo function of the PRLs remains elusive. Here we show that deletion of PRL2, the most ubiquitously expressed PRL family member, leads to impaired placental development and retarded growth at both embryonic and adult stages. Ablation of PRL2 inactivates Akt and blocks glycogen cell proliferation, resulting in reduced spongiotrophoblast and decidual layers in the placenta. These structural defects cause placental hypotrophy and insufficiency, leading to fetal growth retardation. We demonstrate that the tumor suppressor PTEN is elevated in PRL2-deficient placenta. Biochemical analyses indicate that PRL2 promotes Akt activation by down-regulating PTEN through the proteasome pathway. This study provides the first evidence that PRL2 is required for extra-embryonic development and associates the oncogenic properties of PRL2 with its ability to negatively regulate PTEN, thereby activating the PI3K-Akt pathway.


Assuntos
Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/fisiologia , PTEN Fosfo-Hidrolase/metabolismo , Placenta/metabolismo , Proteínas Tirosina Fosfatases/genética , Proteínas Tirosina Fosfatases/fisiologia , Alelos , Proteínas Angiogênicas , Animais , Movimento Celular , Proliferação de Células , Cicloeximida/farmacologia , Células-Tronco Embrionárias/citologia , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Oncogênicas/metabolismo , Gravidez , Prenhez , Proteínas Proto-Oncogênicas c-akt/metabolismo , Trofoblastos/metabolismo
20.
Dev Cell ; 14(2): 298-311, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18267097

RESUMO

Developing myocardial cells respond to signals from the endocardial layer to form a network of trabeculae that characterize the ventricles of the vertebrate heart. Abnormal myocardial trabeculation results in specific cardiomyopathies in humans and yet trabecular development is poorly understood. We show that trabeculation requires Brg1, a chromatin remodeling protein, to repress ADAMTS1 expression in the endocardium that overlies the developing trabeculae. Repression of ADAMTS1, a secreted matrix metalloproteinase, allows the establishment of an extracellular environment in the cardiac jelly that supports trabecular growth. Later during embryogenesis, ADAMTS1 expression initiates in the endocardium to degrade the cardiac jelly and prevent excessive trabeculation. Thus, the composition of cardiac jelly essential for myocardial morphogenesis is dynamically controlled by ADAMTS1 and its chromatin-based transcriptional regulation. Modification of the intervening microenvironment provides a mechanism by which chromatin regulation within one tissue layer coordinates the morphogenesis of an adjacent layer.


Assuntos
Proteínas ADAM/metabolismo , DNA Helicases/metabolismo , Endocárdio/metabolismo , Coração/embriologia , Morfogênese , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Proteínas ADAM/genética , Proteína ADAMTS1 , Animais , Linhagem Celular , DNA Helicases/genética , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Endotélio/citologia , Endotélio/metabolismo , Eritropoese , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Ventrículos do Coração/embriologia , Humanos , Camundongos , Neovascularização Fisiológica , Proteínas Nucleares/genética , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Transcrição/genética , Saco Vitelino/irrigação sanguínea
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa