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1.
J Invasive Cardiol ; 2024 May 23.
Article de Anglais | MEDLINE | ID: mdl-38787923

RÉSUMÉ

An 83-year-old woman with symptomatic severe aortic stenosis was referred for transcatheter aortic valve replacement. Diagnostic left heart catheterization documented diffuse 3-vessel coronary artery disease.

2.
J Am Soc Echocardiogr ; 36(9): 967-977, 2023 09.
Article de Anglais | MEDLINE | ID: mdl-37331608

RÉSUMÉ

BACKGROUND: Right ventricular (RV) function is important in the evaluation of cardiac function, but its assessment using standard transthoracic echocardiography (TTE) remains challenging. Cardiac magnetic resonance imaging (CMR) is considered the gold standard. The American Society of Echocardiography recommends surrogate measures of RV function and RV ejection fraction (RVEF) by TTE, including fractional area change (FAC), free wall strain (FWS), and tricuspid annular planar systolic excursion (TAPSE), but they require technical expertise in acquisition and quantification. METHODS: The aim of this study was to evaluate the sensitivity, specificity, and positive and negative predictive values of FAC, FWS, and TAPSE derived using a rapid, novel artificial intelligence (AI) software (LVivoRV) from a single-plane transthoracic echocardiographic apical four-chamber, RV-focused view without ultrasound-enhancing agents for detecting abnormal RV function compared with CMR-derived RVEF. RV dysfunction was defined as RVEF < 50% and RVEF < 40% on CMR. RESULTS: TTE and CMR were performed within a median of 10 days (interquartile range, 2-32 days) of each other in 225 consecutive patients without interval procedural or pharmacologic intervention. The sensitivity and negative predictive value to detect CMR-defined RV dysfunction when all three AI-derived parameters (FAC, FWS, and TAPSE) were abnormal were 91% and 96%, while those of expert physician reads were 91% and 97%. Specificity and positive predictive value were lower (50% and 32%) compared with expert physician-read echocardiograms (82% and 56%). CONCLUSIONS: AI-derived measurements of FAC, FWS, and TAPSE had excellent sensitivity and negative predictive value for ruling out significant RV dysfunction (CMR RVEF < 40%), comparable with that of expert physician readers, but lower specificity. Thus AI, using American Society of Echocardiography guidelines, may serve as a useful screening tool for rapid bedside assessment to exclude significant RV dysfunction.


Sujet(s)
Dysfonction ventriculaire droite , Humains , Dysfonction ventriculaire droite/imagerie diagnostique , Intelligence artificielle , IRM dynamique/méthodes , Échocardiographie , Imagerie par résonance magnétique , Débit systolique , Fonction ventriculaire droite
3.
Echocardiography ; 39(3): 473-482, 2022 03.
Article de Anglais | MEDLINE | ID: mdl-35178746

RÉSUMÉ

BACKGROUND: Quantification of left ventricular ejection fraction (LVEF) by transthoracic echocardiography (TTE) is operator-dependent, time-consuming, and error-prone. LVivoEF by DIA is a new artificial intelligence (AI) software, which displays the tracking of endocardial borders and rapidly quantifies LVEF. We sought to assess the accuracy of LVivoEF compared to cardiac magnetic resonance imaging (cMRI) as the reference standard and to compare LVivoEF to the standard-of-care physician-measured LVEF (MD-EF) including studies with ultrasound enhancing agents (UEAs). METHODS: In 273 consecutive patients, we compared MD-EF and AI-derived LVEF to cMRI. AI-derived LVEF was obtained from a non-UEA four-chamber view without manual correction. Thirty-one patients were excluded: 25 had interval interventions or incomplete TTE or cMRI studies and six had uninterpretable non-UEA apical views. RESULTS: In the 242 subjects, the correlation between AI and cMRI was r = .890, similar to MD-EF and cMRI with r = .891 (p = 0.48). Of the 126 studies performed with UEAs, the correlation of AI using the unenhanced four-chamber view was r = .89, similar to MD-EF with r = .90. In the 116 unenhanced studies, AI correlation was r = .87, similar to MD-EF with r = .84. From Bland-Altman analysis, LVivoEF underreported the LVEF with a bias of 3.63 ± 7.40% EF points compared to cMRI while MD-EF to cMRI had a bias of .33 ± 7.52% (p = 0.80). CONCLUSIONS: Compared to cMRI, LVivoEF can accurately quantify LVEF from a standard apical four-chamber view without manual correction. Thus, LVivoEF has the ability to improve and expedite LVEF quantification.


Sujet(s)
Intelligence artificielle , Fonction ventriculaire gauche , Humains , Imagerie par résonance magnétique/méthodes , Reproductibilité des résultats , Logiciel , Débit systolique
4.
Int J Cardiol ; 346: 100-102, 2022 01 01.
Article de Anglais | MEDLINE | ID: mdl-34798211

RÉSUMÉ

BACKGROUND: There are currently no clear guidelines regarding the use of ultrasound enhancing agents (UEAs) with transthoracic echocardiography (TTE) for patients hospitalized with Covid-19. We investigated whether the performance of TTE with UEAs provides more diagnostic information and allows for shorter acquisition time compared to unenhanced TTE imaging in this patient population. METHODS: We analyzed the TTEs of 107 hospitalized Covid-19 patients between April and June 2020 who were administered UEAs (Definity®, Lantheus). The time to acquire images with and without UEAs was calculated. A level III echocardiographer determined if new, clinically significant findings were visualized with the addition of UEAs. RESULTS: There was a mean of 11.84±3.59 UEA cineloops/study vs 20.74±8.10 non-UEA cineloops/study (p < 0.0001). Mean time to acquire UEA cineloop images was 72.28±28.18 s/study compared to 188.07±86.04 s/study for non-UEA cineloop images (p < 0.0001). Forty-eight patients (45%) had at least one new finding on UEA imaging, with a total of 62 new findings seen. New information gained with UEAs was more likely to be found in patients with acute respiratory distress syndrome (21 vs 9, p < 0.001) and in those on mechanical ventilation (21 vs 15, p = 0.046). CONCLUSIONS: TTE with UEAs required less time and fewer cineloop images compared to non-UEA imaging in patients hospitalized with Covid-19. Additionally, Covid-19 patients with severe respiratory disease benefited most with regard to new diagnostic information. Health care personnel should consider early use of UEAs in select hospitalized Covid-19 patients in order to reduce exposure and optimize diagnostic yield.


Sujet(s)
COVID-19 , Échocardiographie , Humains , SARS-CoV-2 , Échographie
5.
J Am Coll Cardiol ; 78(22): 2196-2212, 2021 11 30.
Article de Anglais | MEDLINE | ID: mdl-34823663

RÉSUMÉ

Myocardial bridging (MB) is a congenital coronary anomaly in which a segment of the epicardial coronary artery traverses through the myocardium for a portion of its length. The muscle overlying the artery is termed a myocardial bridge, and the intramyocardial segment is referred to as a tunneled artery. MB can occur in any coronary artery, although is most commonly seen in the left anterior descending artery. Although traditionally considered benign in nature, increasing attention is being given to specific subsets of MB associated with ischemic symptomatology. The advent of contemporary functional and anatomic imaging modalities, both invasive and noninvasive, have dramatically improved our understanding of dynamic pathophysiology associated with MBs. This review provides a contemporary overview of epidemiology, pathobiology, diagnosis, functional assessment, and management of MBs.


Sujet(s)
Coronarographie/méthodes , Circulation coronarienne/physiologie , Vaisseaux coronaires/imagerie diagnostique , Prise en charge de la maladie , Pont myocardique/diagnostic , Angiographie par tomodensitométrie/méthodes , Vaisseaux coronaires/physiopathologie , Humains , Pont myocardique/physiopathologie , Pont myocardique/thérapie , Échographie interventionnelle
7.
Int J Cardiol Heart Vasc ; 36: 100877, 2021 Oct.
Article de Anglais | MEDLINE | ID: mdl-34611544

RÉSUMÉ

BACKGROUND: Although population-based studies have demonstrated racial heterogeneity in coronary artery calcium (CAC) burden, the degree to which such associations extend to percutaneous coronary intervention (PCI) cohorts remains poorly characterized. We sought to evaluate the associations between race/ethnicity and CAC in a PCI population. METHODS: This single center retrospective study analyzed 1025 patients with prior CAC who underwent PCI between January 1, 2012 and May 15, 2020. Patients were grouped as non-Hispanic White (NHW, N = 779), non-Hispanic Black (NHB, N = 81) and Hispanic (H, N = 165). Associations between race and CAC (Agatston units) were examined using negative binomial regression while adjusting for baseline parameters. RESULTS: Among the 1025 patients (mean age 65.8, 70% male) who underwent PCI, NHW, NHB, and H populations had median CAC scores of 760, 500, and 462 Agatston units, respectively (p < 0.0001). Hispanic patients displayed a higher burden of diabetes mellitus, hypertension and hyperlipidemia compared with other groups. After adjusting for baseline differences and compared with NHW, the inverse association between Hispanic and CAC persisted (ß = -324.1, p < 0.0001) whereas differences were not significant for NHB (ß = -51.5, p = 0.67). CONCLUSIONS: Despite a higher risk clinical phenotype, Hispanic patients who underwent PCI had significantly lower CAC compared with non-Hispanic patients. Thus, current risk stratification models using universalized CAC scores may underestimate the risk for the Hispanic population. Race/ethnicity-informed CAC thresholds may better guide clinical decisions.

8.
J Am Coll Cardiol ; 77(11): 1470-1479, 2021 03 23.
Article de Anglais | MEDLINE | ID: mdl-33736830

RÉSUMÉ

Cardiovascular disease is the most common cause of death in patients with end-stage renal disease (ESRD). The initiation of dialysis for treatment of ESRD exacerbates chronic electrolyte and hemodynamic perturbations. Rapid large shifts in effective intravascular volume and electrolyte concentrations ultimately lead to subendocardial ischemia, increased left ventricular wall mass, and diastolic dysfunction, and can precipitate serious arrhythmias through a complex pathophysiological process. These factors, unique to advanced kidney disease and its treatment, increase the overall incidence of acute coronary syndrome and sudden cardiac death. To date, risk prediction models largely fail to incorporate the observed cardiovascular mortality in the CKD population; however, multimodality imaging may provide an additional prognostication and risk stratification. This comprehensive review discusses the cardiovascular risks associated with hemodialysis, and explores the pathophysiology and the novel utilization of multimodality imaging in CKD to promote a personalized approach for these patients with implications for future research.


Sujet(s)
Maladies cardiovasculaires , Défaillance rénale chronique , Imagerie multimodale/méthodes , Dialyse rénale/effets indésirables , Maladies cardiovasculaires/complications , Maladies cardiovasculaires/diagnostic , Maladies cardiovasculaires/physiopathologie , Mort subite cardiaque/étiologie , Mort subite cardiaque/prévention et contrôle , Évolution de la maladie , Humains , Défaillance rénale chronique/complications , Défaillance rénale chronique/thérapie , Pronostic , Dialyse rénale/méthodes , Appréciation des risques/méthodes
9.
J Am Coll Cardiol ; 75(1): 42-56, 2020 01 07.
Article de Anglais | MEDLINE | ID: mdl-31726193

RÉSUMÉ

BACKGROUND: The current trends of unhealthy lifestyle behaviors in underserved communities are disturbing. Thus, effective health promotion strategies constitute an unmet need. OBJECTIVES: The purpose of this study was to assess the impact of 2 different lifestyle interventions on parents/caregivers of children attending preschools in a socioeconomically disadvantaged community. METHODS: The FAMILIA (Family-Based Approach in a Minority Community Integrating Systems-Biology for Promotion of Health) study is a cluster-randomized trial involving 15 Head Start preschools in Harlem, New York. Schools, and their children's parents/caregivers, were randomized to receive either an "individual-focused" or "peer-to-peer-based" lifestyle intervention program for 12 months or control. The primary outcome was the change from baseline to 12 months in a composite health score related to blood pressure, exercise, weight, alimentation, and tobacco (Fuster-BEWAT Score [FBS]), ranging from 0 to 15 (ideal health = 15). To assess the sustainability of the intervention, this study evaluated the change of FBS at 24 months. Main pre-specified secondary outcomes included changes in FBS subcomponents and the effect of the knowledge of presence of atherosclerosis as assessed by bilateral carotid/femoral vascular ultrasound. Mixed-effects models were used to test for intervention effects. RESULTS: A total of 635 parents/caregivers were enrolled: mean age 38 ± 11 years, 83% women, 57% Hispanic/Latino, 31% African American, and a baseline FBS of 9.3 ± 2.4 points. The mean within-group change in FBS from baseline to 12 months was ∼0.20 points in all groups, with no overall between-group differences. However, high-adherence participants to the intervention exhibited a greater change in FBS than their low-adherence counterparts: 0.30 points (95% confidence interval: 0.03 to 0.57; p = 0.027) versus 0.00 points (95% confidence interval: -0.43 to 0.43; p = 1.0), respectively. Furthermore, the knowledge by the participant of the presence of atherosclerosis significantly boosted the intervention effects. Similar results were sustained at 24 months. CONCLUSIONS: Although overall significant differences were not observed between intervention and control groups, the FAMILIA trial highlights that high adherence rates to lifestyle interventions may improve health outcomes. It also suggests a potential contributory role of the presentation of atherosclerosis pictures, providing helpful information to improve future lifestyle interventions in adults.


Sujet(s)
Famille/ethnologie , Promotion de la santé/économie , Promotion de la santé/méthodes , Vie autonome/économie , Comportement de réduction des risques , Populations vulnérables/ethnologie , Adulte , Enfant d'âge préscolaire , Femelle , Études de suivi , Humains , Mâle , Adulte d'âge moyen , Minorités
10.
Curr Biol ; 24(19): 2327-2334, 2014 Oct 06.
Article de Anglais | MEDLINE | ID: mdl-25220058

RÉSUMÉ

Majewski osteodysplastic primordial dwarfism type II (MOPDII) is caused by mutations in the centrosome gene pericentrin (PCNT) that lead to severe pre- and postnatal growth retardation. As in MOPDII patients, disruption of pericentrin (Pcnt) in mice caused a number of abnormalities including microcephaly, aberrant hemodynamics analyzed by in utero echocardiography, and cardiovascular anomalies; the latter being associated with mortality, as in the human condition. To identify the mechanisms underlying these defects, we tested for changes in cell and molecular function. All Pcnt(-/-) mouse tissues and cells examined showed spindle misorientation. This mouse phenotype was associated with misdirected ventricular septal growth in the heart, decreased proliferative symmetric divisions in brain neural progenitors, and increased misoriented divisions in fibroblasts; the same phenotype was seen in fibroblasts from three MOPDII individuals. Misoriented spindles were associated with disrupted astral microtubules and near complete loss of a unique set of centrosome proteins from spindle poles (ninein, Cep215, centriolin). All these proteins appear to be crucial for microtubule anchoring and all interacted with Pcnt, suggesting that Pcnt serves as a molecular scaffold for this functionally linked set of spindle pole proteins. Importantly, Pcnt disruption had no detectable effect on localization of proteins involved in the cortical polarity pathway (NuMA, p150(glued), aPKC). Not only do these data reveal a spindle-pole-localized complex for spindle orientation, but they identify key spindle symmetry proteins involved in the pathogenesis of MOPDII.


Sujet(s)
Antigènes/génétique , Nanisme/génétique , Retard de croissance intra-utérin/génétique , Microcéphalie/génétique , Microtubules/génétique , Mitose , Ostéochondrodysplasies/génétique , Appareil du fuseau/génétique , Animaux , Antigènes/métabolisme , Centrosome/métabolisme , Modèles animaux de maladie humaine , Nanisme/physiopathologie , Embryon de mammifère/embryologie , Retard de croissance intra-utérin/physiopathologie , Humains , Souris , Microcéphalie/physiopathologie , Ostéochondrodysplasies/physiopathologie , Appareil du fuseau/métabolisme , Pôles du fuseau/génétique , Pôles du fuseau/métabolisme
11.
Pediatr Res ; 76(6): 500-7, 2014 Dec.
Article de Anglais | MEDLINE | ID: mdl-25167202

RÉSUMÉ

BACKGROUND: Mouse mutants are used to model human congenital cardiovascular disease. Few studies exist comparing normal cardiovascular development in mice vs. humans. We carried out a systematic comparative analysis of mouse and human fetal cardiovascular development. METHODS: Episcopic fluorescence image capture (EFIC) was performed on 66 wild-type mouse embryos from embryonic day (E) 9.5 to birth; 2-dimensional and 3-dimensional datasets were compared with EFIC and magnetic resonance images from a study of 52 human fetuses (Carnegie stage 13-23). RESULTS: Time course of atrial, ventricular, and outflow septation were outlined and followed a similar sequence in both species. Bilateral venae cavae and prominent atrial appendages were seen in the mouse fetus; in human fetuses, atrial appendages were small, and a single right superior vena cava was present. In contrast to humans with separate pulmonary vein orifices, a pulmonary venous confluence with one orifice enters the left atrium in mice. CONCLUSION: The cardiac developmental sequences observed in mouse and human fetuses are comparable, with minor differences in atrial and venous morphology. These comparisons of mouse and human cardiac development strongly support that mouse morphogenesis is a good model for human development.


Sujet(s)
Coeur foetal/embryologie , Coeur/embryologie , Animaux , Auricule de l'atrium/embryologie , Septum interatrial/embryologie , Âge gestationnel , Valves cardiaques/embryologie , Ventricules cardiaques/embryologie , Humains , Imagerie par résonance magnétique , Souris , Morphogenèse , Imagerie optique , Spécificité d'espèce , Septum interventriculaire/embryologie
12.
Dev Cell ; 22(5): 940-51, 2012 May 15.
Article de Anglais | MEDLINE | ID: mdl-22595669

RÉSUMÉ

The intraflagellar transport (IFT) system is required for building primary cilia, sensory organelles that cells use to respond to their environment. IFT particles are composed of about 20 proteins, and these proteins are highly conserved across ciliated species. IFT25, however, is absent from some ciliated organisms, suggesting that it may have a unique role distinct from ciliogenesis. Here, we generate an Ift25 null mouse and show that IFT25 is not required for ciliary assembly but is required for proper Hedgehog signaling, which in mammals occurs within cilia. Mutant mice die at birth with multiple phenotypes, indicative of Hedgehog signaling dysfunction. Cilia lacking IFT25 have defects in the signal-dependent transport of multiple Hedgehog components including Patched-1, Smoothened, and Gli2, and fail to activate the pathway upon stimulation. Thus, IFT function is not restricted to building cilia where signaling occurs, but also plays a separable role in signal transduction events.


Sujet(s)
Flagelles/métabolisme , Protéines Hedgehog/métabolisme , Protéines et peptides de signalisation intracellulaire/métabolisme , Animaux , Transport biologique , Techniques de culture cellulaire , Cils vibratiles/métabolisme , Régulation de l'expression des gènes au cours du développement , Protéines Hedgehog/génétique , Protéines et peptides de signalisation intracellulaire/génétique , Facteurs de transcription Krüppel-like/génétique , Facteurs de transcription Krüppel-like/métabolisme , Souris , Souris de lignée C57BL , Souris knockout , Récepteurs patched , Récepteur Patched-1 , Récepteurs de surface cellulaire/génétique , Récepteurs de surface cellulaire/métabolisme , Récepteurs couplés aux protéines G/génétique , Récepteurs couplés aux protéines G/métabolisme , Transduction du signal , Récepteur Smoothened , Protéine à doigts de zinc Gli2
13.
Dev Dyn ; 239(6): 1585-95, 2010 Jun.
Article de Anglais | MEDLINE | ID: mdl-20503356

RÉSUMÉ

Rapid advances in medical imaging are facilitating the clinical assessment of first-trimester human embryos at increasingly earlier stages. To obtain data on early human development, we used magnetic resonance (MR) imaging and episcopic fluorescence capture (EFIC) to acquire digital images of human embryos spanning the time of dynamic tissue remodeling and organogenesis (Carnegie stages 13 to 23). These imaging data sets are readily resectioned digitally in arbitrary planes, suitable for rapid high-resolution three-dimensional (3D) observation. Using these imaging datasets, a web-accessible digital Human Embryo Atlas (http://apps.devbio.pitt.edu/humanatlas/) was created containing serial 2D images of human embryos in three standard histological planes: sagittal, frontal, and transverse. In addition, annotations and 3D reconstructions were generated for visualizing different anatomical structures. Overall, this Human Embryo Atlas is a unique resource that provides morphologic data of human developmental anatomy that can accelerate basic research investigations into developmental mechanisms that underlie human congenital anomalies.


Sujet(s)
Anatomie artistique , Atlas comme sujet , Premier trimestre de grossesse , Imagerie diagnostique , Femelle , Humains , Traitement d'image par ordinateur , Imagerie par résonance magnétique/méthodes , Grossesse
14.
J Am Soc Echocardiogr ; 23(3): 315-23, 2010 Mar.
Article de Anglais | MEDLINE | ID: mdl-20097527

RÉSUMÉ

BACKGROUND: The authors conducted an ultrasound interrogation of a mutant mouse model with a Dnah5 mutation to determine whether cardiac mechanics may be affected by reversal of cardiac situs. This mutant is a bona fide model of primary ciliary dyskinesia, with surviving homozygous mice showing either situs solitus (SS) or situs inversus totalis (SI). METHODS: High-frequency ultrasound interrogations of 27 neonatal and infant Dnah5 mutant mice, 16 with SS and 11 with SI, were conducted using an ultra-high-frequency biomicroscope. Electrocardiographic and respiratory gating were used to reconstruct high-resolution two-dimensional cines at 1,000 Hz, with speckle-tracking echocardiography used to further analyze midchamber and apical rotation. RESULTS: All SS mice exhibited the expected counterclockwise apical rotation as viewed caudocranially, and surprisingly, the same counterclockwise motion was also observed in SI mice. Speckle-tracking analysis confirmed counterclockwise systolic rotation in both SS and SI mice, and this increased in magnitude from the subepicardium to the endocardium and from the papillary muscles to the apex. The magnitude of apical endocardial rotation was not different for SS and SI mice (5.64+/-0.75 degrees and 5.76+/-1.90 degrees, respectively, P=.93). The anatomic segments responsible for the largest components of apical endocardial systolic rotation differed between the SS and SI hearts (P=.004). In both, the two largest contributors to rotation were offset 180 degrees from each other, but the anatomic regions differed between them. In SS hearts, maximal regional rotation occurred at the anterior mid-septum and posterolateral free wall, while in SI hearts, it was derived from the posterior septum and the anterolateral free wall. Analysis by episcopic fluorescence image capture histology of representative SI and SS mice showed normal intracardiac and segmental anatomy ({S,D,S} or {I,L,I}) without intracardiac defects. CONCLUSIONS: These results show that mirror-image cardiac looping did not result in mirror-image rotation of the morphologic left ventricle. These findings suggest that further studies are warranted to evaluate whether fiber orientation and cardiac mechanics may be abnormal in individuals with reversal of cardiac situs. The results of this study indicate that cardiac looping and myofiber orientation may be independently regulated.


Sujet(s)
Échocardiographie/méthodes , Imagerie d'élasticité tissulaire/méthodes , Interprétation d'images assistée par ordinateur/méthodes , Situs inversus/imagerie diagnostique , Anomalie de torsion/imagerie diagnostique , Dysfonction ventriculaire gauche/imagerie diagnostique , Animaux , Souris , Souris knockout , Mutation , Reproductibilité des résultats , Rotation , Sensibilité et spécificité , Situs inversus/complications , Anomalie de torsion/étiologie , Dysfonction ventriculaire gauche/étiologie
15.
Am J Physiol Heart Circ Physiol ; 297(5): H1617-28, 2009 Nov.
Article de Anglais | MEDLINE | ID: mdl-19717734

RÉSUMÉ

Neural crest-specific ablation of BMP type IA receptor (BMPRIA) causes embryonic lethality by embryonic day (E) 12.5, and this was previously postulated to arise from a myocardial defect related to signaling by a small population of cardiac neural crest cells (cNCC) in the epicardium. However, as BMP signaling via cNCC is also required for proper development of the outflow tract cushions, precursors to the semilunar valves, a plausible alternate or additional hypothesis is that heart failure may result from an outflow tract cushion defect. To investigate whether the outflow tract cushions may serve as dynamic valves in regulating hemodynamic function in the early embryo, in this study we used noninvasive ultrasound biomicroscopy-Doppler imaging to quantitatively assess hemodynamic function in mouse embryos with P0-Cre transgene mediated neural crest ablation of Bmpr1a (P0 mutants). Similar to previous studies, the neural crest-deleted Bmpr1a P0 mutants died at approximately E12.5, exhibiting persistent truncus arteriosus, thinned myocardium, and congestive heart failure. Surprisingly, our ultrasound analyses showed normal contractile indices, heart rate, and atrioventricular conduction in the P0 mutants. However, reversed diastolic arterial blood flow was detected as early as E11.5, with cardiovascular insufficiency and death rapidly ensuing by E12.5. Quantitative computed tomography showed thinning of the outflow cushions, and this was associated with a marked reduction in cell proliferation. These results suggest BMP signaling to cNCC is required for growth of the outflow tract cushions. This study provides definitive evidence that the outflow cushions perform a valve-like function critical for survival of the early mouse embryo.


Sujet(s)
Récepteurs de la protéine morphogénique osseuse de type I/métabolisme , Protéines morphogénétiques osseuses/métabolisme , Cardiopathies congénitales/métabolisme , Défaillance cardiaque/métabolisme , Valves cardiaques/métabolisme , Coeur/embryologie , Myocarde/métabolisme , Crête neurale/métabolisme , Transduction du signal , Animaux , Troubles du rythme cardiaque/embryologie , Troubles du rythme cardiaque/métabolisme , Troubles du rythme cardiaque/physiopathologie , Artères/embryologie , Artères/métabolisme , Artères/physiopathologie , Récepteurs de la protéine morphogénique osseuse de type I/déficit , Récepteurs de la protéine morphogénique osseuse de type I/génétique , Débit cardiaque , Mouvement cellulaire , Prolifération cellulaire , Perte de l'embryon , Génotype , Âge gestationnel , Coeur/physiopathologie , Cardiopathies congénitales/embryologie , Cardiopathies congénitales/physiopathologie , Défaillance cardiaque/embryologie , Défaillance cardiaque/physiopathologie , Rythme cardiaque , Valves cardiaques/embryologie , Valves cardiaques/physiopathologie , Souris , Souris de lignée C57BL , Souris knockout , Microscopie acoustique , Contraction myocardique , Myocarde/anatomopathologie , Crête neurale/anatomopathologie , Phénotype , Débit sanguin régional , Tomodensitométrie , Tronc artériel commun/embryologie , Tronc artériel commun/métabolisme , Tronc artériel commun/physiopathologie , Échographie-doppler
17.
PLoS Genet ; 4(12): e1000315, 2008 Dec.
Article de Anglais | MEDLINE | ID: mdl-19112494

RÉSUMÉ

Eukaryotic cells often use proteins localized to the ciliary membrane to monitor the extracellular environment. The mechanism by which proteins are sorted, specifically to this subdomain of the plasma membrane, is almost completely unknown. Previously, we showed that the IFT20 subunit of the intraflagellar transport particle is localized to the Golgi complex, in addition to the cilium and centrosome, and hypothesized that the Golgi pool of IFT20 plays a role in sorting proteins to the ciliary membrane. Here, we show that IFT20 is anchored to the Golgi complex by the golgin protein GMAP210/Trip11. Mice lacking GMAP210 die at birth with a pleiotropic phenotype that includes growth restriction, ventricular septal defects of the heart, omphalocele, and lung hypoplasia. Cells lacking GMAP210 have normal Golgi structure, but IFT20 is no longer localized to this organelle. GMAP210 is not absolutely required for ciliary assembly, but cilia on GMAP210 mutant cells are shorter than normal and have reduced amounts of the membrane protein polycystin-2 localized to them. This work suggests that GMAP210 and IFT20 function together at the Golgi in the sorting or transport of proteins destined for the ciliary membrane.


Sujet(s)
Protéines de transport/métabolisme , Appareil de Golgi/métabolisme , Protéines nucléaires/métabolisme , Animaux , Sites de fixation , Protéines de transport/composition chimique , Protéines de transport/génétique , Lignée cellulaire , Cellules cultivées , Cils vibratiles/métabolisme , Protéines du cytosquelette , Appareil de Golgi/composition chimique , Appareil de Golgi/génétique , Souris , Souris de lignée C57BL , Souris knockout , Souris transgéniques , Protéines nucléaires/composition chimique , Protéines nucléaires/génétique , Liaison aux protéines , Transport des protéines
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