RESUMO
Statin therapy is a cornerstone in the treatment of systemic vascular diseases. However, statins have failed to translate as therapeutics for pulmonary vascular disease. Early pulmonary vascular disease in the setting of congenital heart disease (CHD) is characterized by endothelial dysfunction, which precedes the more advanced stages of vascular remodeling. These features make CHD an ideal cohort in which to re-evaluate the potential pulmonary vascular benefits of statins, with a focus on endothelial biology. However, it is critical that the full gamut of the pleiotropic effects of statins in the endothelium are uncovered. The purpose of this investigation was to evaluate the therapeutic potential of simvastatin for children with CHD and pulmonary over-circulation, and examine mechanisms of simvastatin action on the endothelium. Our data demonstrate that daily simvastatin treatment preserves endothelial function in our shunt lamb model of pulmonary over-circulation. Further, using pulmonary arterial endothelial cells (PAECs) isolated from Shunt and control lambs, we identified a new mechanism of statin action mediated by increased expression of the endogenous Akt1 inhibitor, C-terminal modifying protein (CTMP). Increases in CTMP were able to decrease the Akt1-mediated mitochondrial redistribution of endothelial nitric oxide synthase (eNOS) which correlated with increased enzymatic coupling, identified by increases in NO generation and decreases in NOS-derived superoxide. Together our data identify a new mechanism by which simvastatin enhances NO signaling in the pulmonary endothelium and identify CTMP as a potential therapeutic target to prevent the endothelial dysfunction that occurs in children born with CHD resulting in pulmonary over-circulation.
Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Doenças Vasculares , Humanos , Criança , Animais , Ovinos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Sinvastatina/farmacologia , Sinvastatina/uso terapêutico , Sinvastatina/metabolismo , Células Endoteliais/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Endotélio/metabolismo , Doenças Vasculares/metabolismo , Óxido Nítrico/metabolismo , Endotélio Vascular/metabolismoRESUMO
BACKGROUND: Although rare, coronary artery anomalies can have significant clinical implications. Total anomalous origin of the coronary arteries from the pulmonary artery (TCAPA) represents a rare subtype of coronary artery anomaly for which little is known. The aim of this review was to characterise the presentation, utilised diagnostic modalities, associated cardiac lesions, and treatment strategies in patients with TCAPA. METHODS: A systematic review was performed for cases of TCAPA using PubMed, Embase, and Web of Science. Keywords searched included "total anomalous origin of the coronary arteries from the pulmonary artery," "single ostium anomalous coronary artery from the pulmonary artery," and "anomalous origin of both coronary arteries from the pulmonary artery." RESULTS: Fifty-seven cases of TCAPA were identified in 50 manuscripts. Fifty-eight per cent of patients were male and the median age at presentation was 10 days (mean 1.71 ± 6.6 years, range 0 days-39 years). Most patients were symptomatic at the time of presentation; cyanosis (n = 22) and respiratory distress (n = 14) were the most common symptoms. Cases were most commonly diagnosed at autopsy (n = 26, 45.6%), but operative intervention was pursued in 22 cases (45.6%); aortic re-implantation (n = 14) and a Takeuchi-type repair (n = 7) were the most common routes of repair. CONCLUSIONS: The clinical presentation of patients with TCAPA was found to be variable, likely related to the presence of associated cardiac lesions. TCAPA should be considered in patients with suspected anomalous origin of the left coronary artery from the pulmonary artery for the serious consequences that can occur if not promptly corrected.
Assuntos
Doença da Artéria Coronariana , Anomalias dos Vasos Coronários , Anomalias dos Vasos Coronários/diagnóstico , Anomalias dos Vasos Coronários/epidemiologia , Cianose , Humanos , Recém-Nascido , Masculino , Artéria Pulmonar/diagnóstico por imagemRESUMO
The natural history of pulmonary vascular disease associated with congenital heart disease (CHD) depends on associated hemodynamics. Patients exposed to increased pulmonary blood flow (PBF) and pulmonary arterial pressure (PAP) develop pulmonary vascular disease more commonly than patients exposed to increased PBF alone. To investigate the effects of these differing mechanical forces on physiologic and molecular responses, we developed two models of CHD using fetal surgical techniques: 1) left pulmonary artery (LPA) ligation primarily resulting in increased PBF and 2) aortopulmonary shunt placement resulting in increased PBF and PAP. Hemodynamic, histologic, and molecular studies were performed on control, LPA, and shunt lambs as well as pulmonary artery endothelial cells (PAECs) derived from each. Physiologically, LPA, and to a greater extent shunt, lambs demonstrated an exaggerated increase in PAP in response to vasoconstricting stimuli compared with controls. These physiologic findings correlated with a pathologic increase in medial thickening in pulmonary arteries in shunt lambs but not in control or LPA lambs. Furthermore, in the setting of acutely increased afterload, the right ventricle of control and LPA but not shunt lambs demonstrates ventricular-vascular uncoupling and adverse ventricular-ventricular interactions. RNA sequencing revealed excellent separation between groups via both principal components analysis and unsupervised hierarchical clustering. In addition, we found hyperproliferation of PAECs from LPA lambs, and to a greater extent shunt lambs, with associated increased angiogenesis and decreased apoptosis in PAECs derived from shunt lambs. A further understanding of mechanical force-specific drivers of pulmonary artery pathology will enable development of precision therapeutics for pulmonary hypertension associated with CHD.
Assuntos
Aorta/fisiopatologia , Hemodinâmica , Artéria Pulmonar/fisiopatologia , Doença Cardiopulmonar/fisiopatologia , Remodelação Vascular , Animais , Aorta/metabolismo , Aorta/patologia , Pressão Arterial/fisiologia , Proliferação de Células , Oclusão Coronária/genética , Oclusão Coronária/metabolismo , Oclusão Coronária/fisiopatologia , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Feto , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Pulmão/metabolismo , Pulmão/patologia , Pulmão/fisiopatologia , Óxido Nítrico/metabolismo , Gravidez , Cultura Primária de Células , Hipertensão Arterial Pulmonar/fisiopatologia , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Circulação Pulmonar/fisiologia , Doença Cardiopulmonar/congênito , Doença Cardiopulmonar/metabolismo , Doença Cardiopulmonar/patologia , OvinosRESUMO
Lymphatic abnormalities associated with congenital heart disease are well described, yet the underlying mechanisms remain poorly understood. Using a clinically relevant ovine model of congenital heart disease with increased pulmonary blood flow, we have previously demonstrated that lymphatic endothelial cells (LECs) exposed in vivo to chronically increased pulmonary lymph flow accumulate ROS and have decreased bioavailable nitric oxide (NO). Peroxisome proliferator-activated receptor-γ (PPAR-γ), which abrogates production of cellular ROS by NADPH oxidase, is inhibited by Krüppel-like factor 2 (KLF2), a flow-induced transcription factor. We hypothesized that chronically increased pulmonary lymph flow induces a KLF2-mediated decrease in PPAR-γ and an accumulation of cellular ROS, contributing to decreased bioavailable NO in LECs. To better understand the mechanisms that transduce the abnormal mechanical forces associated with chronically increased pulmonary lymph flow, LECs were isolated from the efferent vessel of the caudal mediastinal lymph node of control ( n = 5) and shunt ( n = 5) lambs. KLF2 mRNA and protein were significantly increased in shunt compared with control LECs, and PPAR-γ mRNA and protein were significantly decreased. In control LECs exposed to shear forces in vitro, we found similar alterations to KLF2 and PPAR-γ expression. In shunt LECs, NADPH oxidase subunit expression was increased, and bioavailable NO was significantly lower. Transfection of shunt LECs with KLF2 siRNA normalized PPAR-γ, ROS, and bioavailable NO. Conversely, pharmacological inhibition of PPAR-γ in control LECs increased ROS equivalent to levels in shunt LECs at baseline. Taken together, these data suggest that one mechanism by which NO-mediated lymphatic function is disrupted after chronic exposure to increased pulmonary lymph flow is through altered KLF2-dependent PPAR-γ signaling, resulting in increased NADPH oxidase activity, accumulation of ROS, and decreased bioavailable NO. NEW & NOTEWORTHY Lymphatic endothelial cells, when exposed in vivo to chronically elevated pulmonary lymph flow in a model of congenital heart disease with increased pulmonary blood flow, demonstrate Krüppel-like factor 2-dependent disrupted peroxisome proliferator-activated receptor-γ signaling that results in the accumulation of reactive oxygen species and decreased bioavailable nitric oxide.
Assuntos
Células Endoteliais/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Pulmão/fisiologia , Vasos Linfáticos/metabolismo , PPAR gama/metabolismo , Transdução de Sinais , Animais , Células Cultivadas , Feminino , Fatores de Transcrição Kruppel-Like/genética , Pulmão/metabolismo , Vasos Linfáticos/citologia , Vasos Linfáticos/fisiologia , Óxido Nítrico/metabolismo , PPAR gama/genética , Espécies Reativas de Oxigênio/metabolismo , OvinosRESUMO
The right ventricular (RV) response to pulmonary arterial hypertension (PAH) is heterogeneous. Most patients have maladaptive changes with RV dilation and RV failure, whereas some, especially patients with PAH secondary to congenital heart disease, have an adaptive response with hypertrophy and preserved systolic function. Mechanisms for RV adaptation to PAH are unknown, despite RV function being a primary determinant of mortality. In our congenital heart disease ovine model with fetally implanted aortopulmonary shunt (shunt lambs), we previously demonstrated an adaptive physiological RV response to increased afterload with hypertrophy. In the present study, we examined small noncoding microRNA (miRNA) expression in shunt RV and characterized downstream effects of a key miRNA. RV tissue was harvested from 4-wk-old shunt and control lambs ( n = 5), and miRNA, mRNA, and protein were quantitated. We found differential expression of 40 cardiovascular-specific miRNAs in shunt RV. Interestingly, this miRNA signature is distinct from models of RV failure, suggesting that miRNAs might contribute to adaptive RV hypertrophy. Among RV miRNAs, miR-199b was decreased in the RV with eventual downregulation of nuclear factor of activated T cells/calcineurin signaling. Furthermore, antifibrotic miR-29a was increased in the shunt RV with a reduction of the miR-29 targets collagen type A1 and type 3A1 and decreased fibrosis. Thus, we conclude that the miRNA signature specific to shunt lambs is distinct from RV failure and drives gene expression required for adaptive RV hypertrophy. We propose that the adaptive RV miRNA signature may serve as a prognostic and therapeutic tool in patients with PAH to attenuate or prevent progression of RV failure and premature death. NEW & NOTEWORTHY This study describes a novel microRNA signature of adaptive right ventricular hypertrophy, with particular attention to miR-199b and miR-29a.
Assuntos
Cardiopatias Congênitas/genética , Hipertensão Pulmonar/genética , Hipertrofia Ventricular Direita/genética , MicroRNAs/genética , Transcriptoma , Função Ventricular Direita/genética , Remodelação Ventricular/genética , Adaptação Fisiológica , Animais , Modelos Animais de Doenças , Fibrose , Perfilação da Expressão Gênica/métodos , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/fisiopatologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/fisiopatologia , Hemodinâmica , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/fisiopatologia , Hipertrofia Ventricular Direita/metabolismo , Hipertrofia Ventricular Direita/fisiopatologia , MicroRNAs/metabolismo , Carneiro DomésticoAssuntos
Meios de Contraste , Linfografia , Humanos , Criança , Óleo Etiodado , Tomografia Computadorizada por Raios X , ÁguaAssuntos
Meios de Contraste , Linfografia , Humanos , Criança , Tomografia Computadorizada por Raios X , ÁguaRESUMO
Associated abnormalities of the lymphatic circulation are well described in congenital heart disease. However, their mechanisms remain poorly elucidated. Using a clinically relevant ovine model of a congenital cardiac defect with chronically increased pulmonary blood flow (shunt), we previously demonstrated that exposure to chronically elevated pulmonary lymph flow is associated with: 1) decreased bioavailable nitric oxide (NO) in pulmonary lymph; and 2) attenuated endothelium-dependent relaxation of thoracic duct rings, suggesting disrupted lymphatic endothelial NO signaling in shunt lambs. To further elucidate the mechanisms responsible for this altered NO signaling, primary lymphatic endothelial cells (LECs) were isolated from the efferent lymphatic of the caudal mediastinal node in 4-wk-old control and shunt lambs. We found that shunt LECs (n = 3) had decreased bioavailable NO and decreased endothelial nitric oxide synthase (eNOS) mRNA and protein expression compared with control LECs (n = 3). eNOS activity was also low in shunt LECs, but, interestingly, inducible nitric oxide synthase (iNOS) expression and activity were increased in shunt LECs, as were total cellular nitration, including eNOS-specific nitration, and accumulation of reactive oxygen species (ROS). Pharmacological inhibition of iNOS reduced ROS in shunt LECs to levels measured in control LECs. These data support the conclusion that NOS signaling is disrupted in the lymphatic endothelium of lambs exposed to chronically increased pulmonary blood and lymph flow and may contribute to decreased pulmonary lymphatic bioavailable NO.
Assuntos
Células Endoteliais/enzimologia , Cardiopatias Congênitas/enzimologia , Linfa/metabolismo , Doenças Linfáticas/enzimologia , Vasos Linfáticos/enzimologia , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo , Células Endoteliais/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/fisiopatologia , Doenças Linfáticas/etiologia , Doenças Linfáticas/fisiopatologia , Vasos Linfáticos/efeitos dos fármacos , Vasos Linfáticos/fisiopatologia , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III/genética , Circulação Pulmonar , Espécies Reativas de Oxigênio/metabolismo , Ovinos , Transdução de Sinais , Estresse MecânicoRESUMO
Vascular cell hyperproliferation and metabolic reprogramming contribute to the pathophysiology of pulmonary arterial hypertension (PAH). An important cause of PAH in children with congenital heart disease (CHD) is increased pulmonary blood flow (PBF). To better characterize this disease course we studied early changes in pulmonary artery smooth muscle cell (PASMC) proliferation and metabolism using a unique ovine model of pulmonary overcirculation. Consistent with PAH in adults, PASMCs derived from 4-wk-old lambs exposed to increased PBF (shunt) exhibited increased rates of proliferation. While shunt PASMCs also exhibited significant decreases in mitochondrial oxygen consumption, membrane potential, and tricarboxylic acid (TCA) cycle function, suggesting a switch to Warburg metabolism as observed in advanced PAH in adults, they unexpectedly demonstrated decreased glycolytic lactate production, likely due to enhanced flux through the pentose phosphate pathway (PPP). This may be a response to the marked increase in NADPH oxidase (Nox) activity and decreased NADPH/NADP+ ratios observed in shunt PASMCs. Consistent with these findings, pharmacological inhibition of Nox activity preferentially slowed the growth of shunt PASMCs in vitro. Our results therefore indicate that PASMC hyperproliferation is observed early in the setting of pulmonary overcirculation and is accompanied by a unique metabolic profile that is independent of HIF-1α, PDHK1, or increased glycolytic flux. Our results also suggest that Nox inhibition may help prevent pulmonary overcirculation-induced PAH in children born with CHD.
Assuntos
Proliferação de Células , Hipertensão Pulmonar/metabolismo , Mitocôndrias/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , NADPH Oxidases/metabolismo , Via de Pentose Fosfato , Artéria Pulmonar/metabolismo , Animais , Western Blotting , Células Cultivadas , Modelos Animais de Doenças , Espectroscopia de Ressonância de Spin Eletrônica , Citometria de Fluxo , Imunofluorescência , Glicólise , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Potencial da Membrana Mitocondrial , Metabolômica , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/citologia , Consumo de Oxigênio , Artéria Pulmonar/citologia , Circulação Pulmonar , Espécies Reativas de Oxigênio/metabolismo , Ovinos , Carneiro Doméstico , Superóxidos/metabolismoRESUMO
We recently reported superior right ventricle (RV) performance in response to acute afterload challenge in lambs with a model of congenital heart disease with chronic left-to-right cardiac shunts. Compared with control animals, shunt lambs demonstrated increased contractility because of an enhanced Anrep effect (the slow increase in contractility following myocyte stretch). This advantageous physiological response may reflect preservation of a fetal phenotype, since the RV of shunt lambs remains exposed to increased pressure postnatally. Nitric oxide (NO) production by NO synthase (NOS) is activated by myocyte stretch and is a necessary intermediary of the Anrep response. The purpose of this study was to test the hypothesis that NO signaling is increased in the RV of fetal lambs compared with controls and shunt lambs have persistence of this fetal pattern. An 8-mm graft was placed between the pulmonary artery and aorta in fetal lambs (shunt). NOS isoform expression, activity, and association with activating cofactors were determined in fetal tissue obtained during late-gestation and in 4-wk-old juvenile shunt and control lambs. We demonstrated increased RNA and protein expression of NOS isoforms and increased total NOS activity in the RV of both shunt and fetal lambs compared with control. We also found increased NOS activation and association with cofactors in shunt and fetal RV compared with control. These data demonstrate preserved fetal NOS phenotype and NO signaling in shunt RV, which may partially explain the mechanism underlying the adaptive response to increased afterload seen in the RV of shunt lambs.
Assuntos
Feto/metabolismo , Cardiopatias Congênitas/metabolismo , Ventrículos do Coração/metabolismo , Óxido Nítrico Sintase/genética , Óxido Nítrico/metabolismo , RNA Mensageiro/metabolismo , Animais , Aorta/cirurgia , Modelos Animais de Doenças , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/fisiopatologia , Ventrículos do Coração/enzimologia , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Hipertrofia Ventricular Direita/etiologia , Hipertrofia Ventricular Direita/fisiopatologia , Contração Miocárdica/fisiologia , Miócitos Cardíacos , Óxido Nítrico Sintase/metabolismo , Fenótipo , Artéria Pulmonar/cirurgia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ovinos , Transdução de SinaisRESUMO
INTRODUCTION: Prenatal and early postnatal growth are known to be abnormal in patients with CHD. Although adult metabolic risk is associated with growth later in childhood, little is known of childhood growth in CHD. PATIENTS AND METHODS: Retrospective data were collected on 551 patients with coarctation of the aorta, hypoplastic left heart syndrome, single ventricle physiology, tetralogy of Fallot, transposition of the great arteries, or ventricular septal defects. Weight, height, and body mass index data were converted to Z-scores. Body size at 2 years and growth between 2 and 20 years, 2 and 7 years, and 8 and 15 years were compared with Normative data using a sequential series of mixed-effects linear models. RESULTS: A total of 4660 weight, 2989 height, and 2988 body mass index measurements were analysed. Body size at 2 years of age was affected by cardiac diagnosis and gender. Abnormal growth was frequent and varied depending on cardiac diagnosis, gender, and the time period considered. The most abnormal patterns were seen in patients with tetralogy of Fallot, hypoplastic left heart syndrome, or single ventricle physiology. Potentially high-risk growth, a combination of small body size at 2 years and rapid subsequent growth, was seen in several groups. CONCLUSIONS: Childhood and adolescent growth patterns were gender- and lesion-specific. Several lesions were associated with abnormal patterns of childhood growth known to be associated with an increased risk of adult adiposity or metabolic risk in other populations. Further information is needed on the long-term metabolic risks of survivors of CHD.
Assuntos
Estatura , Índice de Massa Corporal , Peso Corporal , Crescimento , Cardiopatias Congênitas/classificação , Cardiopatias Congênitas/fisiopatologia , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Estudos Retrospectivos , Fatores de RiscoRESUMO
We have previously shown decreased pulmonary lymph flow in our lamb model of chronically increased pulmonary blood flow, created by the in utero placement of an 8-mm aortopulmonary shunt. The purpose of this study was to test the hypothesis that abnormal lymphatic function in shunt lambs is due to impaired lymphatic endothelial nitric oxide (NO)-cGMP signaling resulting in increased lymphatic vascular constriction and/or impaired relaxation. Thoracic duct rings were isolated from 4-wk-old shunt (n = 7) and normal (n = 7) lambs to determine length-tension properties, vascular reactivity, and endothelial NO synthase protein. At baseline, shunt thoracic duct rings had 2.6-fold higher peak to peak tension and a 2-fold increase in the strength of contractions compared with normal rings (P < 0.05). In response to norepinephrine, shunt thoracic duct rings had a 2.4-fold increase in vascular tone compared with normal rings (P < 0.05) and impaired relaxation in response to the endothelium-dependent dilator acetylcholine (63% vs. 13%, P < 0.05). In vivo, inhaled NO (40 ppm) increased pulmonary lymph flow (normalized for resistance) â¼1.5-fold in both normal and shunt lambs (P < 0.05). Inhaled NO exposure increased bioavailable NO [nitrite/nitrate (NOx); â¼2.5-fold in normal lambs and â¼3.4-fold in shunt lambs] and cGMP (â¼2.5-fold in both) in the pulmonary lymph effluent (P < 0.05). Chronic exposure to increased pulmonary blood flow is associated with pulmonary lymphatic endothelial injury that disrupts NO-cGMP signaling, leading to increased resting vasoconstriction, increased maximal strength of contraction, and impaired endothelium-dependent relaxation. Inhaled NO increases pulmonary lymph NOx and cGMP levels and pulmonary lymph flow in normal and shunt lambs. Therapies that augment NO-cGMP signaling within the lymphatic system may provide benefits, warranting further study.
Assuntos
Cardiopatias Congênitas/metabolismo , Contração Muscular , Relaxamento Muscular , Óxido Nítrico/metabolismo , Artéria Pulmonar/fisiopatologia , Circulação Pulmonar , Transdução de Sinais , Ducto Torácico/metabolismo , Administração por Inalação , Animais , Velocidade do Fluxo Sanguíneo , GMP Cíclico/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Endotélio Linfático/metabolismo , Endotélio Linfático/fisiopatologia , Cardiopatias Congênitas/fisiopatologia , Linfa/metabolismo , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Óxido Nítrico/administração & dosagem , Doadores de Óxido Nítrico/farmacologia , Norepinefrina/farmacologia , S-Nitroso-N-Acetilpenicilamina/farmacologia , Ovinos , Transdução de Sinais/efeitos dos fármacos , Ducto Torácico/efeitos dos fármacos , Ducto Torácico/fisiopatologia , Fatores de TempoRESUMO
Patients with pulmonary hypertension associated with congenital heart disease survive longer with preserved right ventricular (RV) function compared with those with primary pulmonary hypertension. The purpose of this study was to test the hypothesis that superior RV performance can be demonstrated, at baseline and when challenged with increased RV afterload, in lambs with chronic left-to-right cardiac shunts compared with control lambs. A shunt was placed between the pulmonary artery and the aorta in fetal lambs (shunt). RV pressure-volume loops were obtained 4 wk after delivery in shunt and control lambs, before and after increased afterload was applied using pulmonary artery banding (PAB). Baseline stroke volume (8.7 ± 1.8 vs. 15.8 ± 2.7 ml, P = 0.04) and cardiac index (73.0 ± 4.0 vs. 159.2 ± 25.1 ml·min(-1)·kg(-1), P = 0.02) were greater in shunts. After PAB, there was no difference in the change in cardiac index (relative to baseline) between groups; however, heart rate (HR) was greater in controls (168 ± 7.3 vs. 138 ± 6.6 beats/min, P = 0.01), and end-systolic elastance (Ees) was greater in shunts (2.63 vs. 1.31 × baseline, P = 0.02). Control lambs showed decreased mechanical efficiency (71% baseline) compared with shunts. With acute afterload challenge, both controls and shunts maintained cardiac output; however, this was via maladaptive responses in controls, while shunts maintained mechanical efficiency and increased contractility via a proposed enhanced Anrep effect-the second, slow inotropic response in the biphasic ventricular response to increased afterload, a novel finding in the RV. The mechanisms related to these physiological differences may have important therapeutic implications.
Assuntos
Cardiopatias Congênitas/fisiopatologia , Ventrículos do Coração/fisiopatologia , Anastomose Cirúrgica , Animais , Aorta/cirurgia , Cardiomegalia , Modelos Animais de Doenças , Feminino , Hipertensão Pulmonar/fisiopatologia , Contração Miocárdica , Gravidez , Artéria Pulmonar/cirurgia , Ovinos , Volume Sistólico , Função Ventricular Direita , Pressão VentricularRESUMO
In a model of congenital heart disease (CHD), we evaluated if chronically increased pulmonary blood flow and pressure were associated with altered respiratory mechanics and gas exchange. Respiratory mechanics and gas exchange were evaluated in 6 shunt, 7 SHAM, and 7 control age-matched lambs. Lambs were anesthetized and mechanically ventilated for 15 min with tidal volume of 10 mL/kg, positive end-expiratory pressure of 5 cmH2O, and inspired oxygen fraction of 0.21. Respiratory system, lung and chest wall compliances (Crs, CL and Ccw, respectively) and resistances (Rrs, RL and Rcw, respectively), and the profile of the elastic pressure-volume curve (%E2) were evaluated. Arterial blood gases and volumetric capnography variables were collected. Comparisons between groups were performed by one-way ANOVA followed by Tukey-Kramer test for normally distributed data and with Kruskal-Wallis test followed by Steel-Dwass test for non-normally distributed data. Average Crs and CL in shunt lambs were 30% and 58% lower than in control, and 56% and 68% lower than in SHAM lambs, respectively. Ccw was 52% and 47% higher and Rcw was 53% and 40% lower in shunt lambs compared to controls and SHAMs, respectively. No difference in %E2 was identified between groups. No difference in respiratory mechanics was observed between control and SHAM lambs. In shunt lambs, Rcw, Crs and CL were decreased and Ccw was increased when compared to control and SHAM lambs. Pulmonary gas exchange did not seem to be impaired in shunt lambs when compared to controls and SHAMs.
RESUMO
Abnormalities of the lymphatic circulation are well recognized in patients with congenital heart defects. However, it is not known how the associated abnormal blood flow patterns, such as increased pulmonary blood flow (PBF), might affect pulmonary lymphatic function and structure. Using well-established ovine models of acute and chronic increases in PBF, we cannulated the efferent lymphatic duct of the caudal mediastinal node and collected and analyzed lymph effluent from the lungs of lambs with acutely increased PBF (n = 6), chronically increased PBF (n = 6), and age-matched normal lambs (n = 8). When normalized to PBF, we found that lymph flow was unchanged following acute increases in PBF but decreased following chronic increases in PBF. The lymph:plasma protein ratio decreased with both acute and chronic increases in PBF. Lymph bioavailable nitric oxide increased following acute increases in PBF but decreased following chronic increases in PBF. In addition, we found perturbations in the transit kinetics of contrast material through the pleural lymphatics of lambs with chronic increases in PBF. Finally, there were structural changes in the pulmonary lymphatic system in lambs with chronic increases in PBF: lymphatics from these lambs were larger and more dilated, and there were alterations in the expression of vascular endothelial growth factor-C, lymphatic vessel endothelial hyaluronan receptor-1, and Angiopoietin-2, proteins known to be important for lymphatic growth, development, and remodeling. Taken together these data suggest that chronic increases in PBF lead to both functional and structural aberrations of lung lymphatics. These findings have important therapeutic implications that warrant further study.
Assuntos
Cardiopatias Congênitas/fisiopatologia , Pulmão/irrigação sanguínea , Pulmão/fisiopatologia , Sistema Linfático/fisiopatologia , Vasos Linfáticos/fisiopatologia , Circulação Pulmonar/fisiologia , Angiopoietina-2/genética , Angiopoietina-2/metabolismo , Animais , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Hemodinâmica/fisiologia , Pulmão/metabolismo , Sistema Linfático/metabolismo , Vasos Linfáticos/metabolismo , Óxido Nítrico/metabolismo , Artéria Pulmonar/metabolismo , Artéria Pulmonar/fisiopatologia , Circulação Pulmonar/genética , Fluxo Sanguíneo Regional/genética , Fluxo Sanguíneo Regional/fisiologia , Ovinos , Fator C de Crescimento do Endotélio Vascular/genética , Fator C de Crescimento do Endotélio Vascular/metabolismoRESUMO
Intracranial hemorrhage (ICH) can be a devastating complication of extracorporeal life support (ECLS); however, studies on the timing of ICH detection by head ultrasound (HUS) are from 2 decades ago, suggesting ICH is diagnosed by day 5 of ECLS. Given advancements in imaging and critical care, our aim was to evaluate if the timing of ICH diagnosis in infants on ECLS support has changed. Patients <6 months old undergoing ECLS 2011-2020 at a tertiary care children's hospital were included. Primary outcome was timing of ICH diagnosis on HUS. Seventy-four infants underwent ECLS for cardiac (54%) or pulmonary (46%) indications. Venoarterial ECLS was most common (88%). Median ECLS duration was 6 days (range 1-26). Sixteen patients were diagnosed with ICH (21.6%), at a median of 2 days postcannulation (range 1-4). Nearly all were <4 weeks old at cannulation (93.8%). In conclusion, one-fifth of infants developed ICH diagnosed by HUS while on ECLS, all within the first 4 days of ECLS, consistent with previous literature. Despite advances in critical care and imaging technology, the temporality of ICH diagnosis in infants on ECLS is unchanged.
Assuntos
Oxigenação por Membrana Extracorpórea , Testes de Coagulação Sanguínea , Criança , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Humanos , Lactente , Estudos Retrospectivos , Resultado do Tratamento , UltrassonografiaRESUMO
Normal growth and development of lymphatic structures depends on mechanical forces created by accumulating interstitial fluid. However, prolonged exposure to pathologic mechanical stimuli generated by chronically elevated lymph flow results in lymphatic dysfunction. The mechanisms that transduce these mechanical forces are not fully understood. Our objective was to investigate molecular mechanisms that alter the growth and metabolism of isolated lymphatic endothelial cells (LECs) exposed to prolonged pathologically elevated lymph flow in vivo within the anatomic and physiologic context of a large animal model of congenital heart disease with increased pulmonary blood flow using in vitro approaches. To this end, late gestation fetal lambs underwent in utero placement of an aortopulmonary graft (shunt). Four weeks after birth, LECs were isolated and cultured from control and shunt lambs. Redox status and proliferation were quantified, and transcriptional profiling and metabolomic analyses were performed. Shunt LECs exhibited hyperproliferative growth driven by increased levels of Hypoxia Inducible Factor 1α (HIF-1α), along with upregulated expression of known HIF-1α target genes in response to mechanical stimuli and shear stress. Compared to control LECs, shunt LECs exhibited abnormal metabolism including abnormalities of glycolysis, the TCA cycle and aerobic respiration. In conclusion, LECs from lambs exposed in vivo to chronically increased pulmonary lymph flow are hyperproliferative, have enhanced expression of HIF-1α and its target genes, and demonstrate altered central carbon metabolism in vitro. Importantly, these findings suggest provocative therapeutic targets for patients with lymphatic abnormalities.
Assuntos
Células Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Linfa/fisiologia , Animais , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Feto/metabolismo , Cardiopatias Congênitas/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Vasos Linfáticos/metabolismo , Óxido Nítrico/metabolismo , Gravidez , Cultura Primária de Células , Circulação Pulmonar/fisiologia , Ovinos/metabolismo , Transdução de Sinais , Estresse Mecânico , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Q fever is a worldwide zoonosis caused by Coxiella burnetii that can lead to abortion, endocarditis, and death in humans. Researchers utilizing parturient domestic ruminants, including sheep, have an increased risk of occupational exposure. This study evaluated the effectiveness of our screening protocol in eliminating C. burnetii-positive sheep from our facility. From August 2010 to May 2018, all ewes (N = 306) and select lambs (N = 272; ovis aries) were screened twice for C. burnetii utilizing a serum Phase I and Phase II antibody immunofluorescence assay (IFA). The first screen was performed by the vendor prior to breeding, and the second screen was performed on arrival to the research facility. Ewes that were positive on arrival screening were quarantined and retested using repeat IFA serology, enzyme-linked immunosorbent assay, buffy coat polymerase chain reaction (PCR), and amniotic fluid PCR. The overall individual seroprevalence of C. burnetii in the flocks tested by the vendor was 14.2%. Ewes with negative Phase I and Phase II IFA results were selected for transport to the research facility. Upon arrival to the facility, two (0.7%) ewes had positive Phase I IFA results. Repeat testing demonstrated seropositivity in one of these two ewes, though amniotic fluid PCR was negative in both. The repeat seropositive ewe was euthanized prior to use in a research protocol. No Q fever was reported among husbandry, laboratory or veterinary staff during the study period. Serologic testing for C. burnetii with IFA prior to transport and following arrival to a research facility limits potential exposure to research staff.
Assuntos
Monitoramento Epidemiológico/veterinária , Programas de Rastreamento/veterinária , Doenças Profissionais/prevenção & controle , Febre Q/prevenção & controle , Doenças dos Ovinos/epidemiologia , Animais , California/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Imunofluorescência/veterinária , Humanos , Programas de Rastreamento/estatística & dados numéricos , Reação em Cadeia da Polimerase/veterinária , Vigilância da População/métodos , Prevalência , Medição de Risco/métodos , Estudos Soroepidemiológicos , Ovinos , Carneiro DomésticoRESUMO
BACKGROUND: Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital cardiac lesion that has been diagnosed in both children and adults with symptoms ranging from an asymptomatic murmur to sudden cardiac death. The aim of this review was to characterize published cases of ARCAPA to better understand this rare congenital coronary anomaly. METHODS: A systematic review was performed using PubMed, Embase, and Google Scholar for cases of ARCAPA. Keywords searched included: "anomalous origin of the right coronary artery from the pulmonary artery" and "ARCAPA." RESULTS: A total of 223 cases of ARCAPA were identified in 193 case reports. There was a slight male predominance (54.5%) and the median age at presentation was 14.0 years. Thirty-eight percent of patients were asymptomatic and most commonly identified during evaluation of a murmur. Angina and dyspnea were the most common presenting symptoms (22.4% and 17.0%, respectively). In symptomatic patients, a bimodal distribution of age at presentation was observed with a peak near birth and another between ages 40 and 60 years. The condition was most commonly diagnosed with coronary angiography (40.4%). Most cases were repaired surgically (72.6%) and reimplantation of the right coronary artery onto the aorta was the most common method of repair (62.3%). CONCLUSIONS: ARCAPA represents a rare coronary anomaly with great variability in clinical presentation. An understanding of the pathophysiology associated with the lesion is critical when determining treatment strategies.
Assuntos
Anomalias dos Vasos Coronários/cirurgia , Vasos Coronários/cirurgia , Artéria Pulmonar/anormalidades , Procedimentos Cirúrgicos Vasculares/métodos , Angiografia Coronária , Anomalias dos Vasos Coronários/diagnóstico , Vasos Coronários/diagnóstico por imagem , Humanos , Artéria Pulmonar/diagnóstico por imagemRESUMO
The risk and progression of pulmonary vascular disease in patients with congenital heart disease is dependent on the hemodynamics associated with different lesions. However, the underlying mechanisms are not understood. Endothelin-1 is a potent vasoconstrictor that plays a key role in the pathology of pulmonary vascular disease. We utilized two ovine models of congenital heart disease: (1) fetal aortopulmonary graft placement (shunt), resulting in increased flow and pressure; and (2) fetal ligation of the left pulmonary artery resulting in increased flow and normal pressure to the right lung, to investigate the hypothesis that high pressure and flow, but not flow alone, upregulates endothelin-1 signaling. Lung tissue and pulmonary arterial endothelial cells were harvested from control, shunt, and the right lung of left pulmonary artery lambs at 3-7 weeks of age. We found that lung preproendothelin-1 mRNA and protein expression were increased in shunt lambs compared to controls. Preproendothelin-1 mRNA expression was modestly increased, and protein was unchanged in left pulmonary artery lambs. These changes resulted in increased lung endothelin-1 levels in shunt lambs, while left pulmonary artery levels were similar to controls. Pulmonary arterial endothelial cells exposed to increased shear stress decreased endothelin-1 levels by five-fold, while cyclic stretch increased levels by 1.5-fold. These data suggest that pressure or an additive effect of pressure and flow, rather than increased flow alone, is the principal driver of increased endothelin signaling in congenital heart disease. Defining the molecular drivers of the pathobiology of pulmonary vascular disease due to differing mechanical forces will allow for a more targeted therapeutic approach.