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1.
Circ Res ; 135(1): 60-75, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38770652

RESUMO

BACKGROUND: Pathogenic concepts of right ventricular (RV) failure in pulmonary arterial hypertension focus on a critical loss of microvasculature. However, the methods underpinning prior studies did not take into account the 3-dimensional (3D) aspects of cardiac tissue, making accurate quantification difficult. We applied deep-tissue imaging to the pressure-overloaded RV to uncover the 3D properties of the microvascular network and determine whether deficient microvascular adaptation contributes to RV failure. METHODS: Heart sections measuring 250-µm-thick were obtained from mice after pulmonary artery banding (PAB) or debanding PAB surgery and properties of the RV microvascular network were assessed using 3D imaging and quantification. Human heart tissues harvested at the time of transplantation from pulmonary arterial hypertension cases were compared with tissues from control cases with normal RV function. RESULTS: Longitudinal 3D assessment of PAB mouse hearts uncovered complex microvascular remodeling characterized by tortuous, shorter, thicker, highly branched vessels, and overall preserved microvascular density. This remodeling process was reversible in debanding PAB mice in which the RV function recovers over time. The remodeled microvasculature tightly wrapped around the hypertrophied cardiomyocytes to maintain a stable contact surface to cardiomyocytes as an adaptation to RV pressure overload, even in end-stage RV failure. However, microvasculature-cardiomyocyte contact was impaired in areas with interstitial fibrosis where cardiomyocytes displayed signs of hypoxia. Similar to PAB animals, microvascular density in the RV was preserved in patients with end-stage pulmonary arterial hypertension, and microvascular architectural changes appeared to vary by etiology, with patients with pulmonary veno-occlusive disease displaying a lack of microvascular complexity with uniformly short segments. CONCLUSIONS: 3D deep tissue imaging of the failing RV in PAB mice, pulmonary hypertension rats, and patients with pulmonary arterial hypertension reveals complex microvascular changes to preserve the microvascular density and maintain a stable microvascular-cardiomyocyte contact. Our studies provide a novel framework to understand microvascular adaptation in the pressure-overloaded RV that focuses on cell-cell interaction and goes beyond the concept of capillary rarefaction.


Assuntos
Hipertensão Pulmonar , Imageamento Tridimensional , Camundongos Endogâmicos C57BL , Animais , Humanos , Camundongos , Hipertensão Pulmonar/fisiopatologia , Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/patologia , Masculino , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Microvasos/fisiopatologia , Microvasos/diagnóstico por imagem , Microvasos/patologia , Remodelação Vascular , Artéria Pulmonar/fisiopatologia , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/patologia , Disfunção Ventricular Direita/fisiopatologia , Disfunção Ventricular Direita/etiologia , Disfunção Ventricular Direita/diagnóstico por imagem , Função Ventricular Direita , Remodelação Ventricular , Modelos Animais de Doenças , Miócitos Cardíacos/patologia
2.
Clin Transplant ; 38(4): e15302, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38567883

RESUMO

INTRODUCTION: As the adult Fontan population with Fontan associated liver disease continues to increase, more patients are being referred for transplantation, including combined heart and liver transplantation. METHODS: We report updated mortality and morbidity outcomes after combined heart and liver transplant in a retrospective cohort series of 40 patients (age 14 to 49 years) with Fontan circulation across two centers from 2006-2022. RESULTS: The 30-day, 1-year, 5-year and 10-year survival rate was 90%, 80%, 73% and 73% respectively. Sixty percent of patients met a composite comorbidity of needing either post-transplant mechanical circulatory support, renal replacement therapy or tracheostomy. Cardiopulmonary bypass time > 283 min (4.7 h) and meeting the composite comorbidity were associated with mortality by Kaplan Meier analysis. CONCLUSION: Further study to mitigate early mortality and the above comorbidities as well as the high risk of bleeding and vasoplegia in this patient population is warranted.


Assuntos
Cardiopatias Congênitas , Transplante de Coração , Hepatopatias , Transplante de Fígado , Adulto , Humanos , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Transplante de Fígado/efeitos adversos , Estudos Retrospectivos , Hepatopatias/cirurgia , Morbidade , Cardiopatias Congênitas/cirurgia
3.
Transpl Int ; 35: 10176, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35340846

RESUMO

Severe primary graft dysfunction (PGD) is the leading cause of early postoperative mortality following orthotopic heart transplantation (OHT). Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been used as salvage therapy. This study aimed to evaluate the outcomes in adult OHT recipients who underwent VA-ECMO for severe PGD. We retrospectively reviewed 899 adult (≥18 years) patients who underwent primary OHT at our institution between 1997 and 2017. Recipients treated with VA-ECMO (19, 2.1%) exhibited a higher incidence of previous cardiac surgery (p = .0220), chronic obstructive pulmonary disease (p = .0352), and treatment with a calcium channel blocker (p = .0018) and amiodarone (p = .0148). Cardiopulmonary bypass (p = .0410) and aortic cross-clamp times (p = .0477) were longer in the VA-ECMO cohort and they were more likely to have received postoperative transfusion (p = .0013); intra-aortic balloon pump (IABP, p < .0001), and reoperation for bleeding or tamponade (p < .0001). The 30-day, 1-year, and overall survival after transplantation of non-ECMO patients were 95.9, 88.8, and 67.4%, respectively, compared to 73.7, 57.9, and 47.4%, respectively in the ECMO cohort. Fourteen (73.7%) of the ECMO patients were weaned after a median of 7 days following OHT (range: 1-12 days). Following OHT, VA-ECMO may be a useful salvage therapy for severe PGD and can potentially support the usage of marginal donor hearts.


Assuntos
Oxigenação por Membrana Extracorpórea , Transplante de Coração , Disfunção Primária do Enxerto , Adulto , Oxigenação por Membrana Extracorpórea/efeitos adversos , Transplante de Coração/efeitos adversos , Humanos , Disfunção Primária do Enxerto/epidemiologia , Disfunção Primária do Enxerto/etiologia , Disfunção Primária do Enxerto/terapia , Estudos Retrospectivos , Doadores de Tecidos
4.
Circulation ; 142(14): 1361-1373, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33017215

RESUMO

BACKGROUND: Many graft configurations are clinically used for valve-sparing aortic root replacement, some specifically focused on recapitulating neosinus geometry. However, the specific impact of such neosinuses on valvular and root biomechanics and the potential influence on long-term durability are unknown. METHODS: Using a custom 3-dimenstional-printed heart simulator with porcine aortic roots (n=5), the anticommissural plication, Stanford modification, straight graft (SG), Uni-Graft, and Valsalva graft configurations were tested in series using an incomplete counterbalanced measures design, with the native root as a control, to mitigate ordering effects. Hemodynamic and videometric data were analyzed using linear models with conduit as the fixed effect of interest and valve as a fixed nuisance effect with post hoc pairwise testing using Tukey's correction. RESULTS: Hemodynamics were clinically similar between grafts and control aortic roots. Regurgitant fraction varied between grafts, with SG and Uni-Graft groups having the lowest regurgitant fractions and anticommissural plication having the highest. Root distensibility was significantly lower in SG versus both control roots and all other grafts aside from the Stanford modification (P≤0.01 for each). All grafts except SG had significantly higher cusp opening velocities versus native roots (P<0.01 for each). Relative cusp opening forces were similar between SG, Uni-Graft, and control groups, whereas anticommissural plication, Stanford modification, and Valsalva grafts had significantly higher opening forces versus controls (P<0.01). Cusp closing velocities were similar between native roots and the SG group, and were significantly lower than observed in the other conduits (P≤0.01 for each). Only SG and Uni-Graft groups experienced relative cusp closing forces approaching that of the native root, whereas relative forces were >5-fold higher in the anticommissural plication, Stanford modification, and Valsalva graft groups. CONCLUSIONS: In this ex vivo modeling system, clinically used valve-sparing aortic root replacement conduit configurations have comparable hemodynamics but differ in biomechanical performance, with the straight graft most closely recapitulating native aortic root biomechanics.


Assuntos
Aorta/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Implante de Prótese Vascular , Prótese Vascular , Modelos Cardiovasculares , Impressão Tridimensional , Animais , Humanos , Suínos
5.
Circulation ; 142(22): 2138-2154, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32933333

RESUMO

BACKGROUND: Concentric and eccentric cardiac hypertrophy are associated with pressure and volume overload, respectively, in cardiovascular disease both conferring an increased risk of heart failure. These contrasting forms of hypertrophy are characterized by asymmetrical growth of the cardiac myocyte in mainly width or length, respectively. The molecular mechanisms determining myocyte preferential growth in width versus length remain poorly understood. Identification of the mechanisms governing asymmetrical myocyte growth could provide new therapeutic targets for the prevention or treatment of heart failure. METHODS: Primary adult rat ventricular myocytes, adeno-associated virus (AAV)-mediated gene delivery in mice, and human tissue samples were used to define a regulatory pathway controlling pathological myocyte hypertrophy. Chromatin immunoprecipitation assays with sequencing and precision nuclear run-on sequencing were used to define a transcriptional mechanism. RESULTS: We report that asymmetrical cardiac myocyte hypertrophy is modulated by SRF (serum response factor) phosphorylation, constituting an epigenomic switch balancing the growth in width versus length of adult ventricular myocytes in vitro and in vivo. SRF Ser103 phosphorylation is bidirectionally regulated by RSK3 (p90 ribosomal S6 kinase type 3) and PP2A (protein phosphatase 2A) at signalosomes organized by the scaffold protein mAKAPß (muscle A-kinase anchoring protein ß), such that increased SRF phosphorylation activates AP-1 (activator protein-1)-dependent enhancers that direct myocyte growth in width. AAV are used to express in vivo mAKAPß-derived RSK3 and PP2A anchoring disruptor peptides that block the association of the enzymes with the mAKAPß scaffold. Inhibition of RSK3 signaling prevents concentric cardiac remodeling induced by pressure overload, while inhibition of PP2A signaling prevents eccentric cardiac remodeling induced by myocardial infarction, in each case improving cardiac function. SRF Ser103 phosphorylation is significantly decreased in dilated human hearts, supporting the notion that modulation of the mAKAPß-SRF signalosome could be a new therapeutic approach for human heart failure. CONCLUSIONS: We have identified a new molecular switch, namely mAKAPß signalosome-regulated SRF phosphorylation, that controls a transcriptional program responsible for modulating changes in cardiac myocyte morphology that occur secondary to pathological stressors. Complementary AAV-based gene therapies constitute rationally-designed strategies for a new translational modality for heart failure.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Crescimento Celular , Insuficiência Cardíaca/metabolismo , Miócitos Cardíacos/metabolismo , Fator de Resposta Sérica/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Adenoviridae/genética , Animais , Animais Recém-Nascidos , Células Cultivadas , Técnicas de Transferência de Genes , Vetores Genéticos/administração & dosagem , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/patologia , Fosforilação/fisiologia , Ratos , Ratos Sprague-Dawley
6.
J Card Surg ; 35(2): 429-430, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31830328

RESUMO

BACKGROUND: A 73-year-old female presented with leg claudication and chest pain. A mobile mass in the ascending aorta was found. RESULTS: The mass was removed through a transverse aortotomy on circulatory arrest via sternotomy. CONCLUSION: Free-floating ascending aortic thrombus is a rare source of peripheral embolization. We advocate for emergent surgical resection to prevent further embolization and stroke.


Assuntos
Aorta/cirurgia , Trombose/cirurgia , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Ecocardiografia Transesofagiana , Feminino , Humanos , Esternotomia , Trombose/diagnóstico por imagem , Trombose/patologia
7.
J Card Surg ; 34(10): 1083-1085, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31389624

RESUMO

This report describes our unique temporary right ventricular assist device (RVAD) implantation technique, which enables early mobilization even during biventricular support and subsequent less invasive RVAD removal without needing resternotomy upon recovery.


Assuntos
Cardiomiopatias/complicações , Ventrículos do Coração/fisiopatologia , Coração Auxiliar , Implantação de Prótese/métodos , Choque Cardiogênico/cirurgia , Função Ventricular Direita/fisiologia , Caminhada/fisiologia , Cardiomiopatias/fisiopatologia , Cardiomiopatias/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Choque Cardiogênico/etiologia , Choque Cardiogênico/fisiopatologia
10.
J Vasc Surg ; 64(4): 1093-9, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26372192

RESUMO

BACKGROUND: Despite promising therapeutic innovation over the last decade, peripheral arterial disease remains a prevalent morbidity, as many patients are still challenged with peripheral ischemia. We hypothesized that delivery of engineered stromal cell-derived factor 1-alpha (ESA) in an ischemic hind limb will yield significant improvement in perfusion. METHODS: Male rats underwent right femoral artery ligation, and animals were randomized to receive a 100 µL injection of saline (n = 9) or 6 µg/kg dosage of equal volume of ESA (n = 12) into the ipsilateral quadriceps muscle. Both groups of animals were also given an intraperitoneal injection of 40 µg/kg of granulocyte macrophage colony-stimulating factor (GMCSF). Perfusion was quantified using a laser Doppler imaging device preoperatively, and on postoperative days 0, 7, and 14. Immunohistochemistry was performed to quantify angiogenesis on day 14, and an mRNA profile was evaluated for angiogenic and inflammatory markers. RESULTS: Compared with the saline/GMCSF group at day 14, the ESA/GMCSF-injected animals had greater reperfusion ratios (Saline/GMCSF, 0.600 ± 0.140 vs ESA/GMCSF, 0.900 ± 0.181; group effect P = .006; time effect P < .0001; group×time effect P < .0001), elevated capillary density (10×; Saline/GMCSF, 6.40 ± 2.01 vs ESA/GMCSF, 18.55 ± 5.30; P < .01), and increased mRNA levels of vascular endothelial growth factor-A (Saline/GMCSF [n = 6], 0.298 ± 0.205 vs ESA/GMCSF [n = 8], 0.456 ± 0.139; P = .03). CONCLUSIONS: Delivery of ESA significantly improves perfusion in a rat model of peripheral arterial disease via improved neovasculogenesis, a finding which may prove beneficial in the treatment strategy for this debilitating disease.


Assuntos
Indutores da Angiogênese/farmacologia , Quimiocina CXCL12/farmacologia , Isquemia/tratamento farmacológico , Neovascularização Fisiológica/efeitos dos fármacos , Engenharia de Proteínas , Músculo Quadríceps/irrigação sanguínea , Músculo Quadríceps/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Indutores da Angiogênese/administração & dosagem , Animais , Velocidade do Fluxo Sanguíneo , Quimiocina CXCL12/administração & dosagem , Modelos Animais de Doenças , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Membro Posterior , Mediadores da Inflamação/metabolismo , Injeções Intramusculares , Isquemia/genética , Isquemia/metabolismo , Isquemia/fisiopatologia , Masculino , Músculo Quadríceps/metabolismo , Ratos Wistar , Recuperação de Função Fisiológica , Fluxo Sanguíneo Regional , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
11.
Cytotherapy ; 18(4): 510-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26971679

RESUMO

BACKGROUND: Bone marrow (BM)-derived mesenchymal stromal cells (MSCs) have shown potential to differentiate into various cell types, including smooth muscle cells (SMCs). The extracellular matrix (ECM) represents an appealing and readily available source of SMCs for use in tissue engineering. In this study, we hypothesized that the ECM could be used to induce MSC differentiation to SMCs for engineered cell-sheet construction. METHODS: Primary MSCs were isolated from the BM of Wistar rats, transferred and cultured on dishes coated with 3 different types of ECM: collagen type IV (Col IV), fibronectin (FN), and laminin (LM). Primary MSCs were also included as a control. The proportions of SMC (a smooth muscle actin [aSMA] and SM22a) and MSC markers were examined with flow cytometry and Western blotting, and cell proliferation rates were also quantified. RESULTS: Both FN and LM groups were able to induce differentiation of MSCs toward smooth muscle-like cell types, as evidenced by an increase in the proportion of SMC markers (aSMA; Col IV 42.3 ± 6.9%, FN 65.1 ± 6.5%, LM 59.3 ± 7.0%, Control 39.9 ± 3.1%; P = 0.02, SM22; Col IV 56.0 ± 7.7%, FN 74.2 ± 6.7%, LM 60.4 ± 8.7%, Control 44.9 ± 3.6%) and a decrease in that of MSC markers (CD105: Col IV 64.0 ± 5.2%, FN 57.6 ± 4.0%, LM 60.3 ± 7.0%, Control 85.3 ± 4.2%; P = 0.03). The LM group showed a decrease in overall cell proliferation, whereas FN and Col IV groups remained similar to control MSCs (Col IV, 9.0 ± 2.3%; FN, 9.8 ± 2.5%; LM, 4.3 ± 1.3%; Control, 9.8 ± 2.8%). CONCLUSIONS: Our findings indicate that ECM selection can guide differentiation of MSCs into the SMC lineage. Fibronectin preserved cellular proliferative capacity while yielding the highest proportion of differentiated SMCs, suggesting that FN-coated materials may be facilitate smooth muscle tissue engineering.


Assuntos
Transdiferenciação Celular , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Miócitos de Músculo Liso/fisiologia , Engenharia Tecidual/métodos , Animais , Proliferação de Células , Separação Celular/métodos , Células Cultivadas , Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Masculino , Músculo Liso/citologia , Músculo Liso/fisiologia , Ratos , Ratos Wistar
12.
Circ Res ; 114(4): 650-9, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24366171

RESUMO

RATIONALE: After myocardial infarction, there is an inadequate blood supply to the myocardium, and the surrounding borderzone becomes hypocontractile. OBJECTIVE: To develop a clinically translatable therapy, we hypothesized that in a preclinical ovine model of myocardial infarction, the modified endothelial progenitor stem cell chemokine, engineered stromal cell-derived factor 1α analog (ESA), would induce endothelial progenitor stem cell chemotaxis, limit adverse ventricular remodeling, and preserve borderzone contractility. METHODS AND RESULTS: Thirty-six adult male Dorset sheep underwent permanent ligation of the left anterior descending coronary artery, inducing an anteroapical infarction, and were randomized to borderzone injection of saline (n=18) or ESA (n=18). Ventricular function, geometry, and regional strain were assessed using cardiac MRI and pressure-volume catheter transduction. Bone marrow was harvested for in vitro analysis, and myocardial biopsies were taken for mRNA, protein, and immunohistochemical analysis. ESA induced greater chemotaxis of endothelial progenitor stem cells compared with saline (P<0.01) and was equivalent to recombinant stromal cell-derived factor 1α (P=0.27). Analysis of mRNA expression and protein levels in ESA-treated animals revealed reduced matrix metalloproteinase 2 in the borderzone (P<0.05), with elevated levels of tissue inhibitor of matrix metalloproteinase 1 and elastin in the infarct (P<0.05), whereas immunohistochemical analysis of borderzone myocardium showed increased capillary and arteriolar density in the ESA group (P<0.01). Animals in the ESA treatment group also had significant reductions in infarct size (P<0.01), increased maximal principle strain in the borderzone (P<0.01), and a steeper slope of the end-systolic pressure-volume relationship (P=0.01). CONCLUSIONS: The novel, biomolecularly designed peptide ESA induces chemotaxis of endothelial progenitor stem cells, stimulates neovasculogenesis, limits infarct expansion, and preserves contractility in an ovine model of myocardial infarction.


Assuntos
Quimiocina CXCL12/farmacologia , Mobilização de Células-Tronco Hematopoéticas/métodos , Células-Tronco Mesenquimais/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Animais , Quimiocina CXCL12/genética , Quimiotaxia/efeitos dos fármacos , Circulação Coronária/efeitos dos fármacos , Modelos Animais de Doenças , Desenho de Fármacos , Hemodinâmica/efeitos dos fármacos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Microcirculação/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Engenharia de Proteínas , Carneiro Doméstico , Pesquisa Translacional Biomédica , Disfunção Ventricular Esquerda/patologia , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/terapia , Remodelação Ventricular/efeitos dos fármacos
13.
Adv Funct Mater ; 25(4): 636-644, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-26526097

RESUMO

Clinical percutaneous delivery of synthetically engineered hydrogels remains limited due to challenges posed by crosslinking kinetics - too fast leads to delivery failure, too slow limits material retention. To overcome this challenge, we exploit supramolecular assembly to localize hydrogels at the injection site and introduce subsequent covalent crosslinking to control final material properties. Supramolecular gels were designed through the separate pendant modifications of hyaluronic acid (HA) by the guest-host pair cyclodextrin and adamantane, enabling shear-thinning injection and high target site retention (>98%). Secondary covalent crosslinking occurred via addition of thiols and Michael-acceptors (i.e., methacrylates, acrylates, vinyl sulfones) on HA and increased hydrogel moduli (E=25.0±4.5kPa) and stability (>3.5 fold in vivo at 28 days). Application of the dual-crosslinking hydrogel to a myocardial infarct model showed improved outcomes relative to untreated and supramolecular hydrogel alone controls, demonstrating its potential in a range of applications where the precise delivery of hydrogels with tunable properties is desired.

14.
Circulation ; 128(11 Suppl 1): S95-104, 2013 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-24030426

RESUMO

BACKGROUND: Cell-mediated angiogenic therapy for ischemic heart disease has had disappointing results. The lack of clinical translatability may be secondary to cell death and systemic dispersion with cell injection. We propose a novel tissue-engineered therapy, whereby extracellular matrix scaffold seeded with endothelial progenitor cells (EPCs) can overcome these limitations using an environment in which the cells can thrive, enabling an insult-free myocardial cell delivery to normalize myocardial biomechanics. METHODS AND RESULTS: EPCs were isolated from the long bones of Wistar rat bone marrow. The cells were cultured for 7 days in media or seeded at a density of 5 × 10(6) cells/cm(2) on a collagen/vitronectin matrix. Seeded EPCs underwent ex vivo modification with stromal cell-derived factor-1α (100 ng/mL) to potentiate angiogenic properties and enhance paracrine qualities before construct formation. Scanning electron microscopy and confocal imaging confirmed EPC-matrix adhesion. In vitro vasculogenic potential was assessed by quantifying EPC cell migration and vascular differentiation. There was a marked increase in vasculogenesis in vitro as measured by angiogenesis assay (8 versus 0 vessels/hpf; P=0.004). The construct was then implanted onto ischemic myocardium in a rat model of acute myocardial infarction. Confocal microscopy demonstrated a significant migration of EPCs from the construct to the myocardium, suggesting a direct angiogenic effect. Myocardial biomechanical properties were uniaxially quantified by elastic modulus at 5% to 20% strain. Myocardial elasticity normalized after implant of our tissue-engineered construct (239 kPa versus normal=193, P=0.1; versus infarct=304 kPa, P=0.01). CONCLUSIONS: We demonstrate restoration and normalization of post-myocardial infarction ventricular biomechanics after therapy with an angiogenic tissue-engineered EPC construct.


Assuntos
Células Endoteliais/fisiologia , Células Endoteliais/transplante , Infarto do Miocárdio/cirurgia , Neovascularização Patológica/cirurgia , Engenharia Tecidual/métodos , Animais , Fenômenos Biomecânicos , Movimento Celular/fisiologia , Células Cultivadas , Masculino , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Neovascularização Patológica/patologia , Neovascularização Patológica/fisiopatologia , Distribuição Aleatória , Ratos , Ratos Wistar
15.
Circulation ; 128(11 Suppl 1): S59-68, 2013 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-24030422

RESUMO

BACKGROUND: Endothelial progenitor cells (EPCs) possess robust therapeutic angiogenic potential, yet may be limited in the capacity to develop into fully mature vasculature. This problem might be exacerbated by the absence of a neovascular foundation, namely pericytes, with simple EPC injection. We hypothesized that coculturing EPCs with smooth muscle cells (SMCs), components of the surrounding vascular wall, in a cell sheet will mimic the native spatial orientation and interaction between EPCs and SMCs to create a supratherapeutic angiogenic construct in a model of ischemic cardiomyopathy. METHODS AND RESULTS: Primary EPCs and SMCs were isolated from Wistar rats. Confluent SMCs topped with confluent EPCs were spontaneously detached from the Upcell dish to create an SMC-EPC bi-level cell sheet. A rodent ischemic cardiomyopathy model was created by ligating the left anterior descending coronary artery. Rats were then immediately divided into 3 groups: cell-sheet transplantation (n=14), cell injection (n=12), and no treatment (n=13). Cocultured EPCs and SMCs stimulated an abundant release of multiple cytokines in vitro. Increased capillary density and improved blood perfusion in the borderzone elucidated the significant in vivo angiogenic potential of this technology. Most interestingly, however, cell fate-tracking experiments demonstrated that the cell-sheet EPCs and SMCs directly migrated into the myocardium and differentiated into elements of newly formed functional vasculature. The robust angiogenic effect of this cell sheet translated to enhanced ventricular function as demonstrated by echocardiography. CONCLUSIONS: Spatially arranged EPC-SMC bi-level cell-sheet technology facilitated the natural interaction between EPCs and SMCs, thereby creating structurally mature, functional microvasculature in a rodent ischemic cardiomyopathy model, leading to improved myocardial function.


Assuntos
Endotélio Vascular/fisiologia , Isquemia Miocárdica/patologia , Miócitos de Músculo Liso/fisiologia , Neovascularização Patológica/patologia , Células-Tronco/fisiologia , Animais , Técnicas de Cocultura , Endotélio Vascular/patologia , Feminino , Humanos , Masculino , Ratos , Ratos Wistar , Células-Tronco/patologia , Fatores de Tempo
16.
Circulation ; 128(11 Suppl 1): S79-86, 2013 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-24030424

RESUMO

BACKGROUND: Exogenously delivered chemokines have enabled neovasculogenic myocardial repair in models of ischemic cardiomyopathy; however, these molecules have short half-lives in vivo. In this study, we hypothesized that the sustained delivery of a synthetic analog of stromal cell-derived factor 1-α (engineered stromal cell-derived factor analog [ESA]) induces continuous homing of endothelial progenitor cells and improves left ventricular function in a rat model of myocardial infarction. METHODS AND RESULTS: Our previously designed ESA peptide was synthesized by the addition of a fluorophore tag for tracking. Hyaluronic acid was chemically modified with hydroxyethyl methacrylate to form hydrolytically degradable hydrogels through free-radical-initiated crosslinking. ESA was encapsulated in hyaluronic acid hydrogels during gel formation, and then ESA release, along with gel degradation, was monitored for more than 4 weeks in vitro. Chemotactic properties of the eluted ESA were assessed at multiple time points using rat endothelial progenitor cells in a transwell migration assay. Finally, adult male Wistar rats (n=33) underwent permanent ligation of the left anterior descending (LAD) coronary artery, and 100 µL of saline, hydrogel alone, or hydrogel+25 µg ESA was injected into the borderzone. ESA fluorescence was monitored in animals for more than 4 weeks, after which vasculogenic, geometric, and functional parameters were assessed to determine the therapeutic benefit of each treatment group. ESA release was sustained for 4 weeks in vitro, remained active, and enhanced endothelial progenitor cell chemotaxis. In addition, ESA was detected in the rat heart >3 weeks when delivered within the hydrogels and significantly improved vascularity, ventricular geometry, ejection fraction, cardiac output, and contractility compared with controls. CONCLUSIONS: We have developed a hydrogel delivery system that sustains the release of a bioactive endothelial progenitor cell chemokine during a 4-week period that preserves ventricular function in a rat model of myocardial infarction.


Assuntos
Quimiocina CXCL12/fisiologia , Células Endoteliais/efeitos dos fármacos , Hidrogéis , Infarto do Miocárdio/tratamento farmacológico , Células-Tronco/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Animais , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Quimiocina CXCL12/administração & dosagem , Preparações de Ação Retardada , Células Endoteliais/metabolismo , Células Endoteliais/fisiologia , Injeções , Masculino , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Ratos , Ratos Wistar , Células-Tronco/metabolismo , Células-Tronco/fisiologia , Função Ventricular Esquerda/fisiologia
18.
J Biomech Eng ; 136(8)2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24860865

RESUMO

Ischemic heart disease is a major health problem worldwide, and current therapies fail to address microrevascularization. Previously, our group demonstrated that the sustained release of novel engineered stromal cell-derived factor 1-a analogue (ESA) limits infarct spreading, collagen deposition, improves cardiac function by promoting angiogenesis in the region surrounding the infarct, and restores the tensile properties of infarcted myocardium. In this study, using a well-established rat model of ischemic cardiomyopathy, we describe a novel and innovative method for analyzing the viscoelastic properties of infarcted myocardium. Our results demonstrate that, compared with a saline control group, animals treated with ESA have significantly improved myocardial relaxation rates, while reducing the transition strain, leading to restoration of left ventricular mechanics.


Assuntos
Quimiocina CXCL12/genética , Quimiocina CXCL12/farmacologia , Elasticidade/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Miocárdio/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Engenharia de Proteínas , Animais , Quimiocina CXCL12/administração & dosagem , Injeções , Masculino , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Ratos , Ratos Wistar , Viscosidade/efeitos dos fármacos
19.
J Card Surg ; 28(6): 770-5, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24118109

RESUMO

BACKGROUND: Continuous flow left ventricular assist devices (CF LVAD) are being implanted with increasing frequency for end-stage heart failure. At the time of LVAD implant, a large proportion of patients have pulmonary hypertension, right ventricular (RV) dysfunction, and tricuspid regurgitation (TR). RV dysfunction and TR can exacerbate renal dysfunction, hepatic dysfunction, coagulopathy, edema, and even prohibit isolated LVAD implant. Repairing TR mandates increased cardiopulmonary bypass time and bicaval cannulation, which should be reserved for the time of orthotopic heart transplantation. We hypothesized that CF LVAD implant would improve pulmonary artery pressures, enhance RV function, and minimize TR, obviating need for surgical tricuspid repair. METHODS: One hundred fourteen continuous flow LVADs implanted from 2005 through 2011 at a single center, with medical management of functional TR, were retrospectively analyzed. Pulmonary artery pressures were measured immediately prior to and following LVAD implant. RV function and TR were graded according to standard echocardiographic criteria, prior to, immediately following, and long-term following LVAD. RESULTS: There was a significant improvement in post-VAD mean pulmonary arterial pressures (26.6 ± 4.9 vs. 30.2 ± 7.4 mmHg, p = 0.008) with equivalent loading pressures (CVP = 12.0 ± 4.0 vs. 12.1 ± 5.1 p = NS). RV function significantly improved, as noted by right ventricular stroke work index (7.04 ± 2.60 vs. 6.05 ± 2.54, p = 0.02). There was an immediate improvement in TR grade and RV function following LVAD implant, which was sustained long term. CONCLUSION: Continuous flow LVAD implant improves pulmonary hypertension, RV function, and tricuspid regurgitation. TR may be managed nonoperatively during CF LVAD implant.


Assuntos
Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/terapia , Coração Auxiliar , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/terapia , Insuficiência da Valva Tricúspide/etiologia , Insuficiência da Valva Tricúspide/terapia , Disfunção Ventricular Direita/etiologia , Disfunção Ventricular Direita/terapia , Idoso , Pressão Arterial , Feminino , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Hipertensão Pulmonar/fisiopatologia , Masculino , Artéria Pulmonar/fisiopatologia , Estudos Retrospectivos , Volume Sistólico , Resultado do Tratamento , Insuficiência da Valva Tricúspide/fisiopatologia , Disfunção Ventricular Direita/fisiopatologia , Função Ventricular Direita
20.
J Invasive Cardiol ; 35(3): E160, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36884365

RESUMO

A complex 15-year treatment history of a 75-year-old man with New York Heart Association class III symptoms is presented via images and video. His treatment history was noteworthy of bicuspid aortic valve (AV) and a ventricular septal defect (VSD), for which he had an AV replacement and VSD closure in 2005. In 2015, he underwent redo AV replacement and root reconstruction. Echocardiography demonstrated severe bioprosthetic AV stenosis and moderate AV regurgitation. Valve-in-valve transcatheter aortic valve replacement with a Sentinel cerebral protection device was recommended. Pre-operative computed tomography scan showed dilated aortic root and descending aorta with evidence of pseudocoarcta- tion. This case highlights the need for multidisciplinary team approach and the in-depth knowledge of various devices and techniques available.


Assuntos
Insuficiência da Valva Aórtica , Estenose da Valva Aórtica , Doença da Válvula Aórtica Bicúspide , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Masculino , Humanos , Idoso , Substituição da Valva Aórtica Transcateter/efeitos adversos , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/cirurgia , Doença da Válvula Aórtica Bicúspide/cirurgia , Próteses Valvulares Cardíacas/efeitos adversos , Resultado do Tratamento
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