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1.
Theranostics ; 11(16): 7755-7766, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335962

RESUMO

Background: Myocardial infarction (MI) evokes an organized remodeling process characterized by the activation and transdifferentiation of quiescent cardiac fibroblasts to generate a stable collagen rich scar. Early fibroblast activation may be amenable to targeted therapy, but is challenging to identify in vivo. We aimed to non-invasively image active fibrosis by targeting the fibroblast activation protein (FAP) expressed by activated (myo)fibroblasts, using a novel positron emission tomography (PET) radioligand [68Ga]MHLL1 after acute MI. Methods: One-step chemical synthesis and manual as well as module-based radiolabeling yielded [68Ga]MHLL1. Binding characteristics were evaluated in murine and human FAP-transfected cells, and stability tested in human serum. Biodistribution in healthy animals was interrogated by dynamic PET imaging, and metabolites were measured in blood and urine. The temporal pattern of FAP expression was determined by serial PET imaging at 7 d and 21 d after coronary artery ligation in mice as percent injected dose per gram (%ID/g). PET measurements were validated by ex vivo autoradiography and immunostaining for FAP and inflammatory macrophages. Results: [68Ga]MHLL1 displayed specific uptake in murine and human FAP-positive cells (p = 0.0208). In healthy mice the tracer exhibited favorable imaging characteristics, with low blood pool retention and dominantly renal clearance. At 7 d after coronary artery ligation, [68Ga]MHLL1 uptake was elevated in the infarct relative to the non-infarcted remote myocardium (1.3 ± 0.3 vs. 1.0 ± 0.2 %ID/g, p < 0.001) which persisted to 21 d after MI (1.3 ± 0.4 vs. 1.1 ± 0.4 %ID/g, p = 0.013). Excess unlabeled compound blocked tracer accumulation in both infarct and non-infarct remote myocardium regions (p < 0.001). Autoradiography and histology confirmed the regional uptake of [68Ga]MHLL1 in the infarct and especially border zone regions, as identified by Masson trichrome collagen staining. Immunostaining further delineated persistent FAP expression at 7 d and 21 d post-MI in the border zone, consistent with tracer distribution in vivo. Conclusion: The simplified synthesis of [68Ga]MHLL1 bears promise for non-invasive characterization of fibroblast activation protein early in remodeling after MI.


Assuntos
Endopeptidases/metabolismo , Radioisótopos de Gálio/farmacologia , Proteínas de Membrana/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Animais , Autorradiografia/métodos , Linhagem Celular Tumoral , Endopeptidases/fisiologia , Fibroblastos/metabolismo , Fibrose/diagnóstico por imagem , Radioisótopos de Gálio/metabolismo , Humanos , Masculino , Proteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Imagem Molecular/métodos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Distribuição Tecidual/fisiologia , Tomografia Computadorizada por Raios X/métodos
3.
PLoS One ; 16(3): e0248196, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33667270

RESUMO

INTRODUCTION: Regulating excessive activation of fibroblasts may be a promising target to optimize extracellular matrix deposition and myocardial stiffness. Fibroblast activation protein alpha (FAP) is upregulated in activated fibroblasts after myocardial infarction (MI), and alters fibroblast migration in vitro. We hypothesized that FAP depletion may have a protective effect on left ventricular (LV) remodeling after MI. MATERIALS AND METHODS: We used the model of chronic MI in homozygous FAP deficient mice (FAP-KO, n = 51) and wild type mice (WT, n = 55) to analyze wound healing by monocyte and myofibroblast infiltration. Heart function and remodeling was studied by echocardiography, morphometric analyses including capillary density and myocyte size, collagen content and in vivo cell-proliferation. In non-operated healthy mice up to 6 months of age, morphometric analyses and collagen content was assessed (WT n = 10, FAP-KO n = 19). RESULTS: Healthy FAP-deficient mice did not show changes in LV structure or differences in collagen content or cardiac morphology. Infarct size, survival and cardiac function were not different between FAP-KO and wildtype mice. FAP-KO animals showed less LV-dilation and a thicker scar, accompanied by a trend towards lower collagen content. Wound healing, assessed by infiltration with inflammatory cells and myofibroblasts were not different between groups. CONCLUSION: We show that genetic ablation of FAP does not impair cardiac wound healing, and attenuates LV dilation after MI in mice. FAP seems dispensable for normal cardiac function and homeostasis.


Assuntos
Endopeptidases/deficiência , Ventrículos do Coração/metabolismo , Proteínas de Membrana/deficiência , Monócitos/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Miofibroblastos/metabolismo , Animais , Dilatação Patológica , Endopeptidases/metabolismo , Feminino , Ventrículos do Coração/patologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Monócitos/patologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miocárdio/patologia , Miofibroblastos/patologia
5.
Anal Chem ; 91(2): 1302-1308, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30543396

RESUMO

Myeloid-derived growth factor (MYDGF in humans, Mydgf in mice) is a secreted protein with previously unknown biological functions. In a recent study, Mydgf was shown to mediate cardiac repair after acute myocardial infarction (MI) in mice. Lack of a sensitive assay to measure MYDGF in the circulation has hampered its further investigation. Here, we developed a liquid chromatography/multiple reaction monitoring-mass spectrometry MYDGF assay, employing SDS-PAGE-based protein fractionation to deplete high-abundant proteins and a stable isotope-labeled synthetic standard peptide for quantification. The assay had a lower limit of quantification of 0.8 ng/mL and a linear range up to 190 ng/mL. Within-run and total imprecision ranged from 8 to 17% and 11 to 20%, respectively. MYDGF plasma concentrations were not affected by either storage at room temperature for 4 h or up to three freeze-thaw cycles. Apparently healthy adults presented with a median (range) MYDGF concentration of 3.3 (1.3-6.7) ng/mL ( n = 120). MYDGF concentrations were elevated 2.7-fold ( P < 0.001) in patients with acute MI ( n = 101) and were associated with inflammatory biomarkers, renal dysfunction, and long-term cardiovascular mortality. The new assay and the favorable preanalytic characteristics of the analyte will facilitate studies into the pathophysiology of MYDGF and its potential use as a biomarker or protein therapeutic in patients with acute MI or other disease states.


Assuntos
Cromatografia Líquida/métodos , Interleucinas/sangue , Espectrometria de Massas/métodos , Infarto do Miocárdio/sangue , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Interleucinas/química , Masculino , Pessoa de Meia-Idade , Proteólise , Tripsina/química , Adulto Jovem
6.
J Thorac Cardiovasc Surg ; 156(2): 662-669, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29525258

RESUMO

BACKGROUND: The HeartMate 3 (HM3; Abbott Laboratories, Lake Forest, Ill) left ventricular assist device (LVAD) received its Conformité Européenne mark for Europe in October 2015 and is currently under investigation of the Food and Drug Administration to gain approval in the United States. Within this study, we present the first real-world experiences, 1-year outcomes, and adverse events of a single-center cohort treated with the HM3. METHODS: We prospectively studied midterm results of 27 consecutive patients receiving the HM3 at a single institution. After HM 3 implantation, survival, causes of death, and complications were recorded for all patients. Follow up was 100% complete. RESULTS: Twenty-seven patients were enrolled into the study. Within 1 year after HM3 implantation, 3 patients underwent heart transplantation and 3 patients died. Thirty-day survival was 88.9%, 6-month 85.2%, and 1-year survival 85.2%. No pump thrombosis and no strokes were observed within the study group. One incident of gastrointestinal bleeding was observed (3.7%). Right heart failure was diagnosed in 1 patient after HM3 implantation (3.7%). No technical complications of the pump were documented. No pump exchanges were necessary. The main complication was LVAD-related infection (22.2%). CONCLUSIONS: The novel LVAD HM3 has already shown excellent Conformité Européenne mark trial results. Within this cohort, 1-year survival after HM3 implantation was 85%. The HM3 showed excellent midterm results with 0% stroke and 0% pump thrombosis rates 1 year after implantation.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Coração Auxiliar , Idoso , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/instrumentação , Procedimentos Cirúrgicos Cardíacos/mortalidade , Procedimentos Cirúrgicos Cardíacos/estatística & dados numéricos , Feminino , Insuficiência Cardíaca , Transplante de Coração , Coração Auxiliar/efeitos adversos , Coração Auxiliar/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Infecções Relacionadas à Prótese , Acidente Vascular Cerebral
7.
Int J Cardiol ; 232: 155-159, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28082091

RESUMO

BACKGROUND: Fibroblast activation protein alpha (FAP) is a membrane-bound serine protease expressed by activated fibroblasts after myocardial infarction (MI). Reduced circulating FAP levels were associated with increased mortality in patients with acute coronary syndrome. We hypothesized that FAP concentrations are altered after acute ST-elevation MI (STEMI), and related to myocardial damage. METHODS: We measured circulating FAP concentrations in blood plasma of 60 patients on admission, day 1, day 3 and day 5 after STEMI, and in 25 apparently healthy blood donors as controls. RESULTS: Plasma FAP concentrations were lower in STEMI patients on admission (71ng/mL) than in blood donors (101ng/mL, P<0.0001). FAP concentrations declined in STEMI patients from admission to day 3 (66ng/mL, P<0.05) and day 5 (57ng/mL, P<0.05). FAP concentrations on day 5 were inversely correlated with maximum CK and maximum CRP levels. In a multiple linear regression analysis, maximum CRP was independently associated with low FAP concentrations on day 5 after STEMI. When stratified according to the absolute amount of FAP change from admission to day 5 (ΔFAP), patients with high ΔFAP (-22ng/mL) had worse left ventricular function, higher levels of hs-cTnT, CK on admission, maximum CK and CRP than patients with low ΔFAP (-3ng/mL). CONCLUSIONS: Our study first demonstrates alterations of circulating FAP concentrations acutely after STEMI. A greater decline of circulating FAP concentrations in the first 5days after STEMI is associated with increased myocardial damage and inflammation. Measurement of circulating FAP might help to better understand the relation of myocardial injury and inflammatory response in the individual patient.


Assuntos
Gelatinases/sangue , Proteínas de Membrana/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Serina Endopeptidases/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos de Superfície , Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Infarto do Miocárdio com Supradesnível do Segmento ST/mortalidade , Taxa de Sobrevida/tendências
8.
Thromb Haemost ; 117(1): 99-104, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-27734075

RESUMO

Prasugrel, a potent thienopyridine, achieves stronger inhibition of platelet activation than clopidogrel. However, onset of inhibition is significantly delayed in patients with acute ST-elevation myocardial infarction (STEMI), as haemodynamic instability and morphine application seem to exhibit significant influence. Since rapid onset of effect was demonstrated in non-STEMI patients when prasugrel was administered only after percutaneous coronary intervention (PCI) without increasing cardiovascular event rates we assessed the efficacy of prasugrel loading immediately after PCI for STEMI instead of pre-loading before revascularisation. We investigated 50 consecutive patients with acute STEMI (mean age 56 ± 10 years) admitted for primary PCI. Prasugrel efficacy was assessed by platelet reactivity index (PRI; VASP assay) before, 1, 2, 4, 6, 12, and 24 hours following an oral loading dose of 60 mg immediately after PCI. High on-treatment platelet reactivity (HTPR) was defined as PRI>50 %. Prasugrel significantly and rapidly reduced platelet reactivity in acute STEMI patients (p<0.0001 at each time point vs control). Morphine application resulted in a significantly higher HTPR rate among patients having received morphine less than 1 hour before prasugrel loading (p<0.001) while concomitant metoclopramide (MCP) treatment did not significantly affect prasugrel efficacy. In conclusion, in contrast to previous reports describing a significant delay in onset of prasugrel-mediated P2Y12 inhibition in acute STEMI, we observed a rapid onset with low HTPR rates comparable to those observed in stable non-STEMI patients. Prasugrel administered directly after primary PCI might therefore be a useful therapeutic strategy in patients with STEMI to provide strong and effective P2Y12 inhibition.


Assuntos
Plaquetas/efeitos dos fármacos , Intervenção Coronária Percutânea , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/administração & dosagem , Cloridrato de Prasugrel/administração & dosagem , Antagonistas do Receptor Purinérgico P2Y/administração & dosagem , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Administração Oral , Idoso , Analgésicos Opioides/uso terapêutico , Plaquetas/metabolismo , Antagonistas dos Receptores de Dopamina D2/uso terapêutico , Esquema de Medicação , Feminino , Humanos , Masculino , Metoclopramida/uso terapêutico , Pessoa de Meia-Idade , Morfina/uso terapêutico , Intervenção Coronária Percutânea/efeitos adversos , Inibidores da Agregação Plaquetária/efeitos adversos , Testes de Função Plaquetária , Cloridrato de Prasugrel/efeitos adversos , Estudos Prospectivos , Antagonistas do Receptor Purinérgico P2Y/efeitos adversos , Receptores Purinérgicos P2Y12/sangue , Receptores Purinérgicos P2Y12/efeitos dos fármacos , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Fatores de Tempo , Resultado do Tratamento
9.
JACC Cardiovasc Imaging ; 8(12): 1417-1426, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26577262

RESUMO

OBJECTIVES: An assay for molecular imaging of myocardial CXCR4 expression was evaluated, in order to obtain mechanistic insights noninvasively based on quantitative positron emission tomography (PET). BACKGROUND: The chemokine receptor CXCR4 has emerged as a therapeutic target after acute myocardial infarction (AMI), because of its role in inflammatory and progenitor cell recruitment. METHODS: PET with the specific CXCR4 ligand, gallium-68 ((68)Ga)-pentixafor, was performed in mice (n = 53) and compared with ex vivo autoradiography, immunohistochemistry, and left ventricular flow cytometry. In addition, 12 patients were imaged at 2 to 8 days after AMI. RESULTS: In mice, (68)Ga-pentixafor identified regional CXCR4 upregulation in the infarct region, peaking at 3 days (infarct/remote [I/R] ratio 1.5 ± 0.2 at 3 days vs. 1.2 ± 0.3 at 7 days; p = 0.03), corresponding to a flow cytometry-based peak of CD45+ leukocytes and immunohistochemical detection of CD68+ macrophages and Ly6G+ granulocytes. Blockade with the CXCR4 antagonist AMD3100 abolished the signal. No specific uptake was found in sham-operated or control animals. Long-term treatment with oral enalapril attenuated the CXCR4 signal (I/R 1.2 ± 0.2 at 3 days and 1.0 ± 0.0.1 at 7 days; p = 0.01 vs. untreated). Patients showed variable degrees of CXCR4 upregulation in the infarct region. No single clinical parameter allowed for prediction of CXCR4 signal strength. At multivariate analysis, a combination of infarct size and time after reperfusion predicted the CXCR4 infarct signal (rmultiple = 0.73; p = 0.03). Infarct signal in the myocardium was paralleled by elevated pentixafor uptake in bone marrow (r = 0.61; p = 0.04), which highlighted systemic interactions. CONCLUSIONS: Targeted PET imaging with (68)Ga-pentixafor identifies the global and regional CXCR4 expression pattern in myocardium and systemic organs. CXCR4 upregulation after AMI coincides with inflammatory cell infiltration, but shows interindividual variability in patients. This may have implications for the response to CXCR4- or other inflammation-targeted therapy, and for subsequent ventricular remodeling.


Assuntos
Imagem Molecular/métodos , Imagem Multimodal/métodos , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/patologia , Receptores CXCR4/metabolismo , Idoso , Animais , Biomarcadores/metabolismo , Modelos Animais de Doenças , Seguimentos , Humanos , Imagem Cinética por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Distribuição Aleatória , Análise de Regressão , Amostragem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Remodelação Ventricular/fisiologia
10.
J Mol Cell Cardiol ; 87: 194-203, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26319660

RESUMO

INTRODUCTION: Fibroblast activation protein α (FAP) is a membrane-bound serine protease expressed by activated fibroblasts during wound healing in the skin. Expression of FAP after myocardial infarction (MI) and potential effects on cardiac wound healing are largely unknown. METHODS: MI was induced in rats and FAP expression was analyzed at 3, 7 and 28 days post-MI by microarray, Western blot and immunohistochemistry. In human hearts after MI, a FAP(+) fibroblast population was identified, and characterized by immunohistochemistry for prolyl-4-hydroxylase ß, α-smooth muscle actin, Thy-1 and vimentin. Signaling pathways leading to FAP expression were studied in human cardiac fibroblasts by Western blot and ELISA using TGFß1, TGF-beta type I-receptor (TGFbR1)-inhibitor SB431542 or the MAPK-inhibitor U0126 as well as siRNA targeting SMAD2 and SMAD3. Finally, fibroblasts were assayed for FAP-dependent migration (modified Boyden-chamber), proliferation (BrdU-assay) and gelatinolytic activity by gelatin zymography. RESULTS: In rats, FAP expression was increased after MI especially in the peri-infarct area peaking at 7 days post-MI. Co-localization analysis identified the majority of FAP(+) cells as activated proto-myofibroblasts and myofibroblasts. Concordantly, FAP(+) fibroblasts were abundant in ischemic tissue of human hearts after MI, but not in healthy control hearts. In vitro, FAP was induced by TGFß1 via the canonical SMAD2/SMAD3 pathway. Depletion of FAP in fibroblasts reduced migratory capacity, while proliferation was not affected. Gelatin zymography revealed gelatinase activity by fibroblast-derived FAP. CONCLUSION: In this study, we show for the first time the expression of FAP in activated fibroblasts after MI and its activation by TGFß1. Effects of FAP on fibroblast migration and gelatinolytic activity indicate a potential role in cardiac wound healing and remodeling.


Assuntos
Proteínas da Matriz Extracelular/metabolismo , Gelatinases/biossíntese , Inflamação/genética , Proteínas de Membrana/biossíntese , Infarto do Miocárdio/genética , Serina Endopeptidases/biossíntese , Fator de Crescimento Transformador beta/metabolismo , Animais , Proteínas da Matriz Extracelular/genética , Gelatinases/genética , Regulação da Expressão Gênica , Humanos , Inflamação/patologia , Proteínas de Membrana/genética , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Ratos , Serina Endopeptidases/genética , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Cicatrização/genética
11.
Mol Imaging Biol ; 17(1): 76-86, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25011975

RESUMO

PURPOSE: Peptides containing the asparagine-glycine-arginine (NGR) motif bind to aminopeptidase N (CD13), which is expressed on inflammatory cells, endothelial cells, and fibroblasts. It is unclear whether radiolabeled NGR-containing tracers could be used for in vivo imaging of the early wound-healing phase after myocardial infarction (MI) using positron emission tomography (PET). PROCEDURES: Uptake of novel tracer [(68)Ga]NGR was assessed together with [(68)Ga]arginine-glycine-aspartic acid ([(68)Ga]RGD) and 2-deoxy-2-[(18) F]fluoro-D-glucose after myocardial ischemia/reperfusion (MI/R) injury using µ-PET and autoradiography, and relative expressions of CD13 and integrin ß3 were assessed in fibroblasts, inflammatory cells, and endothelial cells by immunohistochemistry. RESULTS: In the infarcted myocardium, uptake of [(68)Ga]NGR was maximal from days 3 to 7 after MI/R, and correlated with fibroblast and inflammatory cell infiltration as well as [(68)Ga]RGD uptake. CONCLUSIONS: [(68)Ga]NGR allows noninvasive and sequential determination of CD13 expression in fibroblasts and inflammatory cells by PET. This will facilitate monitoring of CD13 in the individual wound healing processes, allowing patient-specific therapies to improve outcome after MI.


Assuntos
Coração/diagnóstico por imagem , Infarto do Miocárdio/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Motivos de Aminoácidos , Animais , Antígenos CD13/metabolismo , Fibroblastos/diagnóstico por imagem , Fibroblastos/patologia , Radioisótopos de Gálio , Humanos , Imuno-Histoquímica , Inflamação , Masculino , Isquemia Miocárdica/diagnóstico por imagem , Miocárdio/patologia , Oligopeptídeos/química , Ratos , Ratos Wistar , Cicatrização
12.
Int J Cardiol ; 168(4): 3926-31, 2013 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-23932048

RESUMO

BACKGROUND: Fibroblast activation protein α (FAP) is a membrane glycoprotein with dipeptidyl-peptidase and collagenase activity and is expressed in cancer, arthritis, and atherosclerotic plaques. We hypothesized that FAP can be measured quantitatively in the circulation and provide prognostic information in acute coronary syndrome (ACS). METHODS: We assessed the performance of a commercially available FAP ELISA and the pre-analytic characteristics of the marker. We determined FAP concentrations in EDTA plasma samples from 101 apparently healthy blood donors and 407 patients with ACS. Patients were followed for 12 months regarding all-cause mortality and non-fatal myocardial infarction (MI). RESULTS: FAP was stable at room temperature (for 1 day) and 4°C (3 days) and resistant to 3 freeze/thaw cycles. Recovery of recombinant human FAP ranged from 78 to 103% and serial dilutions of spiked samples resulted in measurements within 91 to 120% of expected values. Patients with ACS had lower plasma FAP concentrations compared with blood donors [median (25th-75th percentiles): 84 (69-101) ng/mL vs. 108 (87-124) ng/mL, P < 0.001]. Patients presenting with FAP concentrations in the first quartile had a 3.0-fold higher risk of death (95% confidence interval 1.4-6.2) compared with patients in the second to fourth quartiles (P = 0.004). FAP concentration was not related to the risk of MI. CONCLUSIONS: Our study is the first to associate FAP with prognosis in ACS. The favorable pre-analytic characteristics of FAP will facilitate future studies of the marker in other disease settings associated with altered FAP expression.


Assuntos
Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico , Circulação Sanguínea/fisiologia , Gelatinases/sangue , Proteínas de Membrana/sangue , Serina Endopeptidases/sangue , Síndrome Coronariana Aguda/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Eur J Heart Fail ; 10(2): 119-24, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18279767

RESUMO

OBJECTIVE: Bone marrow (BM)-derived haematopoietic stem cells have been proposed as a potential cell source to functionally engraft the myocardium and to improve cardiac function after myocardial infarction (MI). However, experimental and clinical data are inconsistent. Since the specific characteristics of different BM cell subsets could influence their therapeutic potential we determined the effect of different BM cell populations on left ventricular remodelling after MI. METHODS AND RESULTS: MI was induced in female mice by coronary artery ligation. Surviving mice were randomised to receive either: total BM, mature Lin(+) or primitive Lin(-) cells from male mice, or saline, via intracardiac injection. Injected cells were detected in the infarct and border zone by PCR for Y-chromosomal sequences. Serial transthoracic echocardiography was performed 1, 21, and 42 days after MI. Over a period of 6 weeks, mortality was not different between the groups. After MI, animals exhibited left ventricular dilatation, as expected. Left ventricular remodelling was not influenced by Lin(+) or Lin(-) BM cells but was partially improved by unfractionated BM cell injection. Paracrine secretion of cytokines (e.g. IL-6, GM-CSF) was differentially regulated in supernatants of cultured BM cells. SUMMARY: Treatment with unfractionated BM cells, but not Lin(+), or Lin(-) cells partially improved cardiac remodelling and function after MI. This may be mediated by paracrine effects.


Assuntos
Transplante de Medula Óssea , Transplante de Células-Tronco Mesenquimais , Infarto do Miocárdio/terapia , Remodelação Ventricular , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Comunicação Parácrina/fisiologia , Análise de Sobrevida
14.
Circ Res ; 102(5): 597-606, 2008 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-18202313

RESUMO

Heart failure is the leading cause of death in the elderly, but whether this is the result of a primary aging myopathy dictated by depletion of the cardiac progenitor cell (CPC) pool is unknown. Similarly, whether current lifespan reflects the ineluctable genetic clock or heart failure interferes with the genetically determined fate of the organ and organism is an important question. We have identified that chronological age leads to telomeric shortening in CPCs, which by necessity generate a differentiated progeny that rapidly acquires the senescent phenotype conditioning organ aging. CPC aging is mediated by attenuation of the insulin-like growth factor-1/insulin-like growth factor-1 receptor and hepatocyte growth factor/c-Met systems, which do not counteract any longer the CPC renin-angiotensin system, resulting in cellular senescence, growth arrest, and apoptosis. However, pulse-chase 5-bromodeoxyuridine-labeling assay revealed that the senescent heart contains functionally competent CPCs that have the properties of stem cells. This subset of telomerase-competent CPCs have long telomeres and, following activation, migrate to the regions of damage, where they generate a population of young cardiomyocytes, reversing partly the aging myopathy. The senescent heart phenotype and heart failure are corrected to some extent, leading to prolongation of maximum lifespan.


Assuntos
Células-Tronco Adultas/efeitos dos fármacos , Envelhecimento/efeitos dos fármacos , Insuficiência Cardíaca/terapia , Fator de Crescimento de Hepatócito/uso terapêutico , Fator de Crescimento Insulin-Like I/uso terapêutico , Miócitos Cardíacos/efeitos dos fármacos , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/patologia , Envelhecimento/patologia , Animais , Antígenos de Diferenciação/biossíntese , Apoptose/efeitos dos fármacos , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/biossíntese , Modelos Animais de Doenças , Vias de Administração de Medicamentos , Coração/efeitos dos fármacos , Coração/crescimento & desenvolvimento , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Masculino , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fenótipo , Ratos , Ratos Endogâmicos F344 , Receptores de Fatores de Crescimento/metabolismo , Regeneração/efeitos dos fármacos , Taxa de Sobrevida , Telômero/metabolismo
15.
Proc Natl Acad Sci U S A ; 105(5): 1668-73, 2008 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-18216245

RESUMO

Coronary artery disease is the most common cause of cardiac failure in the Western world, and to date there is no alternative to bypass surgery for severe coronary atherosclerosis. We report that c-kit-positive cardiac progenitor cells (CPCs) activated with insulin-like growth factor 1 and hepatocyte growth factor before their injection in proximity of the site of occlusion of the left coronary artery in rats, engrafted within the host myocardium forming temporary niches. Subsequently, CPCs divided and differentiated into endothelial cells and smooth muscle cells and, to a lesser extent, into cardiomyocytes. The acquisition of vascular lineages appeared to be mediated by the up-regulation of hypoxia-inducible factor 1alpha, which promoted the synthesis and secretion of stromal-derived factor 1 from hypoxic coronary vessels. Stromal-derived factor 1 was critical in the conversion of CPCs to the vascular fate. CPCs formed conductive and intermediate-sized coronary arteries together with resistance arterioles and capillaries. The new vessels were connected with the primary coronary circulation, and this increase in vascularization more than doubled myocardial blood flow in the infarcted myocardium. This beneficial effect, together with myocardial regeneration attenuated postinfarction dilated myopathy, reduced infarct size and improved function. In conclusion, locally delivered activated CPCs generate de novo coronary vasculature and may be implemented clinically for restoration of blood supply to the ischemic myocardium.


Assuntos
Vasos Coronários/fisiologia , Mioblastos Cardíacos/fisiologia , Neovascularização Fisiológica , Regeneração , Células-Tronco/fisiologia , Animais , Diferenciação Celular , Quimiocina CXCL12/metabolismo , Vasos Coronários/citologia , Células Endoteliais/citologia , Feminino , Fator de Crescimento de Hepatócito/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Mioblastos Cardíacos/efeitos dos fármacos , Mioblastos Cardíacos/transplante , Isquemia Miocárdica/metabolismo , Miócitos de Músculo Liso/citologia , Proteínas Proto-Oncogênicas c-kit/análise , Ratos , Ratos Endogâmicos F344 , Transplante de Células-Tronco , Células-Tronco/química , Células-Tronco/efeitos dos fármacos
16.
Proc Natl Acad Sci U S A ; 104(35): 14068-73, 2007 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-17709737

RESUMO

The identification of cardiac progenitor cells in mammals raises the possibility that the human heart contains a population of stem cells capable of generating cardiomyocytes and coronary vessels. The characterization of human cardiac stem cells (hCSCs) would have important clinical implications for the management of the failing heart. We have established the conditions for the isolation and expansion of c-kit-positive hCSCs from small samples of myocardium. Additionally, we have tested whether these cells have the ability to form functionally competent human myocardium after infarction in immunocompromised animals. Here, we report the identification in vitro of a class of human c-kit-positive cardiac cells that possess the fundamental properties of stem cells: they are self-renewing, clonogenic, and multipotent. hCSCs differentiate predominantly into cardiomyocytes and, to a lesser extent, into smooth muscle cells and endothelial cells. When locally injected in the infarcted myocardium of immunodeficient mice and immunosuppressed rats, hCSCs generate a chimeric heart, which contains human myocardium composed of myocytes, coronary resistance arterioles, and capillaries. The human myocardium is structurally and functionally integrated with the rodent myocardium and contributes to the performance of the infarcted heart. Differentiated human cardiac cells possess only one set of human sex chromosomes excluding cell fusion. The lack of cell fusion was confirmed by the Cre-lox strategy. Thus, hCSCs can be isolated and expanded in vitro for subsequent autologous regeneration of dead myocardium in patients affected by heart failure of ischemic and nonischemic origin.


Assuntos
Insuficiência Cardíaca/terapia , Miocárdio/citologia , Células-Tronco/citologia , Células-Tronco/fisiologia , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Técnicas de Cultura de Células , Fusão Celular , Humanos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/fisiologia , Regeneração , Transplante de Células-Tronco
17.
Circ Res ; 101(4): 387-99, 2007 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-17601802

RESUMO

The recognition that the adult heart continuously renews its myocyte compartment raises the possibility that the age and lifespan of myocytes does not coincide with the age and lifespan of the organ and organism. If this were the case, myocyte turnover would result at any age in a myocardium composed by a heterogeneous population of parenchymal cells which are structurally integrated but may contribute differently to myocardial performance. To test this hypothesis, left ventricular myocytes were isolated from mice at 3 months of age and the contractile, electrical, and calcium cycling characteristics of these cells were determined together with the expression of the senescence-associated protein p16(INK4a) and telomere length. The heart was characterized by the coexistence of young, aged, and senescent myocytes. Old nonreplicating, p16(INK4a)-positive, hypertrophied myocytes with severe telomeric shortening were present together with young, dividing, p16(INK4a)-negative, small myocytes with long telomeres. A class of myocytes with intermediate properties was also found. Physiologically, evidence was obtained in favor of the critical role that action potential (AP) duration and I(CaL) play in potentiating Ca(2+) cycling and the mechanical behavior of young myocytes or in decreasing Ca(2+) transients and the performance of senescent hypertrophied cells. The characteristics of the AP appeared to be modulated by the transient outward K(+) current I(to) which was influenced by the different expression of the K(+) channels subunits. Collectively, these observations at the physiological and structural cellular level document that by necessity the heart has to constantly repopulate its myocyte compartment to replace senescent poorly contracting myocytes with younger more efficient cells. Thus, cardiac homeostasis and myocyte turnover regulate cardiac function.


Assuntos
Envelhecimento/fisiologia , Senescência Celular/fisiologia , Coração/fisiologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/fisiologia , Potenciais de Ação/fisiologia , Animais , Cálcio/metabolismo , Linhagem da Célula/fisiologia , Tamanho Celular , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Homeostase/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Contração Miocárdica/fisiologia , Potássio/metabolismo , Células-Tronco/citologia , Células-Tronco/fisiologia , Telômero/fisiologia
18.
Am J Pathol ; 171(2): 507-12, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17556593

RESUMO

Nuclear factor kappaB (NF-kappaB) is a ubiquitous transcription factor activated by various stimuli implicated in ischemia-reperfusion injury. However, the role of NF-kappaB in cardiac ischemia-reperfusion injury has not yet been well defined. Therefore, we investigated reperfusion damage in mice with targeted deletion of the NF-kappaB subunit p50. Electrophoretic mobility shift assays validated NF-kappaB activation in wild-type (WT) but not p50 knockout (KO) mice. KO and WT animals underwent 30 minutes of coronary artery ligation and 24 hours of reperfusion in vivo. Ischemia-reperfusion damage was significantly reduced in the p50 KO when compared with matching WT mice. Although adhesion molecules such as intercellular adhesion molecule were up-regulated in left ventricles of p50 KO animals, fewer neutrophils infiltrated the infarct area, suggesting leukocytes as a potential mediator of the protection observed in the p50 KO. This was confirmed in adoptive transfer experiments: whereas transplantation of KO bone marrow in KO animals sustained the protective effect on ischemia-reperfusion injury, transplantation of WT bone marrow in KO animals abolished it. Thus, deletion of the NF-kappaB subunit p50 reduces ischemia-reperfusion injury in vivo, associated with less neutrophil infiltration. Bone marrow transplantation experiments indicate that impaired NF-kappaB activation in p50 KO leukocytes attenuates cardiac damage.


Assuntos
Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Subunidade p50 de NF-kappa B/genética , Animais , Células da Medula Óssea/metabolismo , Transplante de Medula Óssea/métodos , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Expressão Gênica , Genótipo , Molécula 1 de Adesão Intercelular/genética , Leucócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/cirurgia , Traumatismo por Reperfusão Miocárdica/complicações , Miocárdio/metabolismo , Miocárdio/patologia , Subunidade p50 de NF-kappa B/metabolismo , Selectina-P/genética , Fator de Necrose Tumoral alfa/genética
19.
Circ Res ; 100(4): 536-44, 2007 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-17272809

RESUMO

Recent studies suggest that rather than being terminally differentiated, the adult heart is a self-renewing organ with the capacity to generate new myocytes from cardiac stem/progenitor cells (CS/PCs). This study examined the hypotheses that new myocytes are generated during adolescent growth, to increase myocyte number, and these newly formed myocytes are initially small, mononucleated, proliferation competent, and have immature properties. Ventricular myocytes (VMs) and cKit(+) (stem cell receptor) CS/PCs were isolated from 11- and 22-week feline hearts. Bromodeoxyuridine incorporation (in vivo) and p16(INK4a) immunostaining were measured to assess myocyte cell cycle activity and senescence, respectively. Telomerase activity, contractions, Ca(2+) transients, and electrophysiology were compared in small mononucleated (SMMs) and large binucleated (LBMs) myocytes. Heart mass increased by 101% during adolescent growth, but left ventricular myocyte volume only increased by 77%. Most VMs were binucleated (87% versus 12% mononucleated) and larger than mononucleated myocytes. A greater percentage of SMMs was bromodeoxyuridine positive (SMMs versus LBMs: 3.1% versus 0.8%; P<0.05), and p16(INK4a) negative and small myocytes had greater telomerase activity than large myocytes. Contractions and Ca(2+) transients were prolonged in SMMs versus LBMs and Ca(2+) release was disorganized in SMMs with reduced transient outward current and T-tubule density. The T-type Ca(2+) current, usually seen in fetal/neonatal VMs, was found exclusively in SMMs and in myocytes derived from CS/PC. Myocyte number increases during adolescent cardiac growth. These new myocytes are initially small and functionally immature, with patterns of ion channel expression normally found in the fetal/neonatal period.


Assuntos
Envelhecimento/fisiologia , Proliferação de Células , Coração/crescimento & desenvolvimento , Miócitos Cardíacos/citologia , Miócitos Cardíacos/fisiologia , Animais , Sinalização do Cálcio/fisiologia , Gatos , Crescimento Celular , Células Cultivadas , Coração/anatomia & histologia , Ventrículos do Coração/citologia , Ventrículos do Coração/crescimento & desenvolvimento
20.
Biochem Biophys Res Commun ; 342(3): 773-4, 2006 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-16497270

RESUMO

Nuclear factor kappaB (NF-kappaB) is a ubiquitous transcription factor activated by various stimuli implicated in heart failure progression. However, its activation in heart failure has not been well defined yet. Therefore, we investigated activation of NF-kappaB after myocardial infarction. For the first time, we performed serial, non-invasive in vivo molecular imaging of transcription factor activation in the heart. We used mice expressing a luciferase reporter whose transcription is dependent upon NF-kappaB activation for up to 8 weeks after myocardial infarction. There was a significant increase of NF-kappaB activity with a maximum at day 3 after myocardial infarction when compared to sham controls. Thus, in vivo measurement of the activation of NF-kappaB is feasible. NF-kappaB activity might play an important role for the remodeling process.


Assuntos
Infarto do Miocárdio/metabolismo , NF-kappa B/metabolismo , Imagem Corporal Total , Animais , Camundongos , Camundongos Transgênicos
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