RESUMO
At present there are two recognised guidelines for the echocardiographic assessment of left ventricular diastolic function provided by the British Society of Echocardiography and American Society of Echocardiography/European Association of Cardiovascular Imaging. However, no direct comparison of these guidelines has been performed to establish whether they provide similar diastolic grading. One hundred and eighty-nine consecutive patients in sinus rhythm who underwent transthoracic echocardiography for a primary indication of either heart failure assessment or assessment of left ventricular systolic function were extracted from our database (McKesson Cardiology). Left ventricular diastolic function assessment was performed using both guidelines and the results were compared. Chi-square, Kappa score and one-way ANOVA were used to evaluate the data at a level of P < 0.05. The most frequent outcome was unclassifiable diastolic function with significantly more patients being labelled unclassified with the British compared to American guidelines (47.4 vs 20.5%, P < 0.0001). Having excluded all unclassifiable patients, a significant difference still existed between the two guidelines with a higher proportion of grade one outcomes awarded by the ASE/EACVI guidelines. When grading subcategories were individually compared, there was significantly more grade one diastolic gradings awarded by American compared to the British guidelines (40.7 vs 20.1%, P < 0.0001). In 47% of patients it was not possible to grade diastolic function using the British guidelines, compared to 21% using the American guidelines. For those patients where grading was possible, there was a significant difference in patients classified with normal and grade one diastolic function when using British and American guidelines.
RESUMO
BACKGROUND: Tumor necrosis factor-alpha (TNF) is expressed locally in arteries at sites of balloon injury. In vitro studies have shown that TNF inhibits cell cycle progression and induces apoptosis in endothelial cells. Accordingly, we performed a series of experiments to test the hypothesis that inhibiting TNF could accelerate endothelial recovery after angioplasty. METHODS AND RESULTS: TNF soluble receptor (TNFsr) has been shown to neutralize the actions of TNF in vitro and in vivo. Sprague-Dawley rats received TNFsr versus control IgG through an intraperitoneal injection. De-endothelializing balloon injury was then performed, and animals were killed after 1 week to evaluate re-endothelialization (Evans blue dye staining) and after 2 weeks to evaluate re-endothelialization and endothelial function. At both time points, blockade of TNF using TNFsr resulted in an increase in re-endothelialization, as measured as absolute area and percent area re-endothelialized. TNFsr also accelerated functional endothelial recovery, which manifest as an increase in nitric oxide production. Neointimal thickening was also shown inhibited. CONCLUSIONS: In vivo blockade of TNF accelerates functional endothelial recovery after barotraumatic de-endothelializing injury. These findings suggest that locally expressed TNF acts to inhibit functional endothelial recovery after angioplasty and that transient blockade of TNF may improve the long-term success of angioplasty.
Assuntos
Angioplastia com Balão , Doenças das Artérias Carótidas/tratamento farmacológico , Endotélio Vascular/efeitos dos fármacos , Proteínas Recombinantes de Fusão/administração & dosagem , Recuperação de Função Fisiológica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Angioplastia com Balão/efeitos adversos , Animais , Antígenos CD/genética , Doenças das Artérias Carótidas/etiologia , Doenças das Artérias Carótidas/patologia , Modelos Animais de Doenças , Esquema de Medicação , Endotélio Vascular/lesões , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Imunoglobulina G/administração & dosagem , Imuno-Histoquímica , Injeções Intraperitoneais , Masculino , Óxido Nítrico/biossíntese , Ratos , Ratos Sprague-Dawley , Receptores do Fator de Necrose Tumoral/genética , Receptores Tipo II do Fator de Necrose Tumoral , Proteínas Recombinantes de Fusão/genética , Resultado do Tratamento , Fator de Necrose Tumoral alfa/biossíntese , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/lesões , Túnica Íntima/patologiaRESUMO
Controversy exists about the net effect of alcohol on atherogenesis. A protective effect is assumed, especially from the tannins and phenolic compounds in red wine, owing to their inhibition of low density lipoprotein (LDL) oxidation. However, increased atherogenesis occurs in subjects with moderate to heavy drinking habits. The purpose of this study was to investigate the influence of alcohol in combination with oxysterols on the endothelium. Cultured human arterial endothelial cells (HAECs) served as an in vitro model to test the cellular effects of various oxysterols. Oxysterols (7beta-hydroxycholesterol, 7-ketocholesterol, and cholesterol-5,6-epoxides), which are assumed to be the most toxic constituents of oxidized LDL, induced apoptosis in HAECs through calcium mobilization followed by activation of caspase-3. Ethanol, methanol, isopropanol, tert-butanol, and red wine all potentiated oxysterol-induced cell death up to 5-fold, paralleled by further induction of caspase-3. The alcohol effect occurred in a dose-dependent manner and reached a plateau at 0.05% concentration. Alcohol itself did not affect endothelial cell viability, nor did other solvents such as dimethyl sulfoxide mimic the alcohol effect. So far as the physiologically occurring oxysterols are concerned, this effect was apparent only for oxysterols oxidized at the steran ring. The possibility of alcohol facilitating the uptake of oxysterols into the cell was not supported by the data from an uptake study with radiolabeled compounds. Finally, alcohol in combination with oxysterols did cause a dramatic increase in cytosolic calcium influx. Blockage of calcium influx by the calcium channel blocker aurintricarboxylic acid or the calcium chelator ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid abrogated the alcohol-mediated enhancement of oxysterol toxicity. We describe for the first time a mechanistic concept explaining possible adverse effects of alcohol in conjunction with physiologically occurring oxysterols on atherogenesis.
Assuntos
Álcoois/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/fisiologia , Endotélio Vascular/efeitos dos fármacos , Esteróis/farmacologia , Cálcio/metabolismo , Caspase 3 , Caspases/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Indução Enzimática/efeitos dos fármacos , Etanol/farmacologia , Humanos , Cinética , terc-Butil Álcool/farmacologiaRESUMO
BACKGROUND: Ceramide is an important messenger of TNF- and lipid-induced apoptosis. We previously demonstrated the adverse effect of TNF in the process of reendothelialization as well as the dependence of its effect on cell-cycle regulation. The current study was designed to investigate the linkage between ceramide induced toxicity and growth arrest in human endothelial cells. METHODS AND RESULTS: Cultured human arterial endothelial cells (HAEC) served as an in-vitro model to test the cellular effects of C2-ceramide (C2). C2-induced cell death in HAECs occurred time- and dose-dependently. The LD(50) in subconfluent cells was three times lower than in confluent cell layers (25 vs. 75 microM). C2 caused up to 70% inhibition of BrdU and [3H]thymidine incorporation at non-toxic concentrations as a result of G1 cell-cycle arrest. Downregulation of cyclin A and p21(Cip1/Waf1) protein expression was observed independently of C2-toxicity, while expression of other cell-cycle regulatory genes was not affected. Inhibition of cyclin A protein expression by sequence-specific antisense-oligonucleotides was paralleled by significant growth-inhibition. The protein phosphatase inhibitor okadaic acid induced endothelial cell proliferation, which was completely abrogated by C2. In contrast, aphidicolin-synchronized endothelial cells demonstrated elevated cyclin A levels along with 30% higher BrdU-incorporation and 70% less C2-toxicity. G1-arrested cells, however, showed significantly enhanced C2-toxicity, lack of cyclin A expression and induction of uncleaved caspase-3 (CPP32). CONCLUSIONS: Ceramide abrogates endothelial cell proliferation independently of apoptosis or necrosis at low concentrations (Assuntos
Artérias/efeitos dos fármacos
, Ciclina A/metabolismo
, Endotélio Vascular/efeitos dos fármacos
, Inibidores Enzimáticos/farmacologia
, Esfingosina/farmacologia
, Apoptose/efeitos dos fármacos
, Artérias/citologia
, Artérias/metabolismo
, Contagem de Células
, Técnicas de Cultura de Células
, Divisão Celular/efeitos dos fármacos
, Relação Dose-Resposta a Droga
, Endotélio Vascular/citologia
, Endotélio Vascular/metabolismo
, Fase G1/efeitos dos fármacos
, Humanos
, Fosfoproteínas Fosfatases/fisiologia
, Esfingosina/análogos & derivados
RESUMO
OBJECTIVE: The vitamin-A derivative all-trans retinoic acid (atRA) is a potent regulator of cell growth, differentiation, and matrix formation of various cell types and plays an important role in embryogenesis. However, sparse data are available about its effects on human vessel diseases. Thus, we studied the effects of atRA on human arterial smooth muscle cell (haSMC) and endothelial cell (haEC) proliferation, migration, differentiation and extracellular matrix (ECM) turnover in mono- and transfilter cocultures. METHODS: Effects of atRA on human arterial cells in monocultures were determined using cell counting assays, BrdU-ELISA and MTT-tests. In transfilter cocultures haSMC-growth was studied under the stimulatory effect of proliferating haEC. Using Northern blot analysis, effects of atRA on mRNA expression of ECM-proteins were examined while protein expression and activity of matrix metalloproteinases were determined by Western blotting and zymography. RESULTS: atRA caused a dose dependent inhibition of haSMC-growth in monocultures (IC(50) at 0.022 microM) whereas haEC-growth was inhibited less potently (IC(50) at 97 microM). In addition, proliferation and migration of haSMC through a porous membrane were inhibited dose dependently by micromolar atRA-doses after non-stop and single dose application of atRA on the endothelial side of the complex transfilter coculture system. Immunostainings and Northern blotting demonstrated an enhanced alpha-smooth muscle actin and heavy chain myosin expression in haSMC after atRA-treatment. Whereas mRNA-expression of the glycoproteins thrombospondin-1 and fibronectin were decreased, collagen-1 mRNA expression was even slightly stimulated. Transcription of biglycan and TGF-beta1 were not influenced in a specific manner. Finally, protein expression and activity of the matrix metalloproteinases MMP-2 and MMP-9 were inhibited significantly by atRA. CONCLUSIONS: atRA was found to be a potent inhibitor of both haSMC-proliferation and -migration, even in coculture with haEC releasing growth factors. In addition, redifferentiation, ECM synthesis and ECM degradation were regulated by atRA which also influence haSMC migration and intima formation. Thus, atRA-treatment seems to be a promising strategy for the inhibition of processes involved both in atherosclerosis and restenosis.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Tretinoína/farmacologia , Artérias , Western Blotting , Comunicação Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Técnicas de Cocultura , Depressão Química , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Endotélio Vascular/citologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Humanos , Imuno-Histoquímica , Metaloproteinases da Matriz/metabolismo , Músculo Liso Vascular/citologiaRESUMO
At homeostasis, endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) in the arterial wall are fully differentiated and display a very low proliferative index. However, unlike terminally differentiated cells, mature ECs and VSMCs maintain their ability to dedifferentiate and reenter the cell cycle in response to several environmental stimuli. Because of the contribution of EC and VSMC proliferation to the pathogenesis of several diseases, including cancer and cardiovascular disease, considerable effort has been devoted to elucidate the mechanisms that regulate cell cycle progression in these cell types. These regulatory networks and the implications they may have for cardiovascular disease are reviewed here.
Assuntos
Doenças Cardiovasculares/etiologia , Células Endoteliais/fisiologia , Músculo Liso Vascular/fisiologia , Animais , Ciclo Celular/fisiologia , Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , HumanosRESUMO
This report describes clinical, hemodynamic, and electrophysiologic characteristics of 18 consecutive survivors of sudden cardiac arrest due to idiopathic ventricular fibrillation (VF) between 1986 and 1996. Long-term data in relation to the prescribed therapy are presented. The mean age of the 18 patients was 48 +/- 14 years (median 49). Electrophysiologic studies showed a low inducibility of sustained ventricular tachyarrhythmias in 4 patients (22%). Treatment consisted of class III agents, beta blockers, or implantable cardioverter-defibrillators. Two patients were discharged without any therapy. Therapy control was undertaken either by serial drug testing or by the empirical approach. Serious complications of therapy occurred in 2 patients: 1 patient experienced a proarrhythmic effect of antiarrhythmic drug therapy, and the other patient received multiple inadequate defibrillator discharges due to a defect in the transvenous lead. All but 1 patient (94%) remained free of recurrences of sudden cardiac arrest during a follow-up time of 45 +/- 29 months (median 41). One patient died 2 weeks after surviving cardiac arrest due to intractable VF while receiving sotalol treatment. Therapy guided by electrophysiologic studies did not have any impact on survival. Adverse effects or noncompliance led to discontinuation of drug therapy in 7 patients after a mean period of 31 +/- 30 months. Without any treatment 9 patients remained without recurrences over 45 +/- 33 months. Because of the absence of risk factors for arrhythmia recurrence and criteria to select therapy, randomized prospective studies are warranted to assess the optimal therapies in these young, ostensibly healthy patients.
Assuntos
Parada Cardíaca/etiologia , Fibrilação Ventricular/complicações , Antagonistas Adrenérgicos beta/uso terapêutico , Adulto , Idoso , Antiarrítmicos/uso terapêutico , Biópsia , Cateterismo Cardíaco , Desfibriladores Implantáveis , Eletrocardiografia Ambulatorial , Feminino , Seguimentos , Imagem do Acúmulo Cardíaco de Comporta , Parada Cardíaca/mortalidade , Cardiopatias/complicações , Cardiopatias/diagnóstico , Cardiopatias/terapia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Estudos Retrospectivos , Taxa de Sobrevida , Fibrilação Ventricular/fisiopatologia , Fibrilação Ventricular/terapiaRESUMO
To evaluate the pathogenetic role of cerebral blood flow (CBF) changes occurring before and during the development of acute mountain sickness (AMS), peak mean middle cerebral artery flow velocities () were assessed by transcranial Doppler sonography in 10 subjects at 490-m altitude, and during three 12-min periods immediately (SA1), 3 (SA2), and 6 (SA3) h after decompression to a simulated altitude of 4,559 m. AMS cerebral scores increased from 0. 16 +/- 0.14 at baseline to 0.44 +/- 0.31 at SA1, 1.11 +/- 0.88 at SA2 (P < 0.05), and 1.43 +/- 1.03 at SA3 (P < 0.01); correspondingly, three, seven, and eight subjects had AMS. Absolute and relative at simulated altitude, expressed as percentages of low-altitude values (%), did not correlate with AMS cerebral scores. Average % remained unchanged, because % increased in three and remained unchanged or decreased in seven subjects at SA2 and SA3. These results suggest that CBF is not important in the pathogenesis of AMS and shows substantial interindividual differences during the first hours at simulated altitude.
Assuntos
Doença da Altitude/fisiopatologia , Circulação Cerebrovascular/fisiologia , Doença Aguda , Adulto , Pressão do Ar , Câmaras de Exposição Atmosférica , Pressão Sanguínea/fisiologia , Artérias Cerebrais/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Ultrassonografia Doppler TranscranianaRESUMO
Anabolic steroids are frequently abused, thus increasing the risk of cardiovascular disease, despite the known unfavorable influence on lipid profiles. We report on a young bodybuilder who presented with ventricular tachycardia as the first manifestation of severe underlying coronary heart disease. Coronary angiogram revealed severe stenotic lesions in the right coronary artery and the left descending coronary artery, and hypokinetic regions corresponded to posterolateral and anterior myocardial infarctions. This young patient had a history without any coronary risk factors, but with a 2-year abuse of the anabolic steroid stanazolol. No report published so far has shown possible atherogenic consequences of long-term abuse of stanazolol.
Assuntos
Anabolizantes/efeitos adversos , Doença das Coronárias/induzido quimicamente , Estanozolol/efeitos adversos , Transtornos Relacionados ao Uso de Substâncias/complicações , Adulto , Doença das Coronárias/complicações , Humanos , Masculino , Infarto do Miocárdio/induzido quimicamente , Taquicardia Ventricular/etiologiaRESUMO
The case of an non-addict young caucasian with isolated tricuspid valve endocarditis in congenital ventricular septal defect (VSD) is presented. Despite antibiotic treatment the patient suffered from recurrent right sided pneumonias. A computed tomography of the chest revealed an abscess localized in the right lower lung with signs of cavitation. Echocardiography identified a vegetation located at the anterior tricuspid leaflet due to a jet lesion through the VSD. ECG-gated MRI revealed normal left ventricular function and localized the septal defect and a jet against the anterior tricuspid valve leaflet. The patient underwent open heart surgery and the VSD was closed. Now, two years later, the patient is free from any symptoms or complications. This case illustrates that noninvasive techniques like echocardiography and ECG-gated MRI can not only accurately image cardiac anatomy in patients with ventricular septal defect but additionally provide information about the pathomechanism of the development of jet lesions resulting in valvular vegetations. Operative correction of underlying cardiac disease in nonaddicts with complicating tricuspid valve endocarditis might be a favourable treatment especially when antibiotic treatment fails to cure the infection.
Assuntos
Ecocardiografia , Endocardite Bacteriana/diagnóstico por imagem , Endocardite Bacteriana/etiologia , Comunicação Interventricular/complicações , Adulto , Endocardite Bacteriana/microbiologia , Comunicação Interventricular/cirurgia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Infecções Estafilocócicas/diagnóstico por imagem , Infecções Estafilocócicas/etiologia , Infecções Estreptocócicas/diagnóstico por imagem , Infecções Estreptocócicas/etiologiaAssuntos
Anti-Infecciosos/uso terapêutico , Ciprofloxacina/uso terapêutico , Empiema Pleural/microbiologia , Infecções por Salmonella/microbiologia , Salmonella enteritidis/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , Empiema Pleural/diagnóstico por imagem , Empiema Pleural/tratamento farmacológico , Humanos , Masculino , Infecções por Salmonella/tratamento farmacológico , Tomografia Computadorizada por Raios XRESUMO
The clinical data of 722 patients admitted for acute myocardial infarction to the coronary care unit of the Hannover Medical School were retrospectively analyzed. Six hundred patients survived through the fifth day of their hospital stay. We evaluated 142 variables from each patient, i.e., previous cardiac manifestations, drug-history, acute complications, laboratory data, intensive care treatment and the 1-year outcome. One-hundred-sixty-nine patients underwent cardiac catheterization before being discharged from the hospital. Thirty-two variables showed to be predictive of 1-year survival in the univariate analysis, although performance of logistic regression analysis revealed only seven parameters to be independent predictors: age (p < 0.0001), glycoside intake before infarction (p = 0.0317), acute heart failure (p = 0.0005), late (occurring after 48 h) ventricular tachycardia or fibrillation (p = 0.0003), maximum of serum creatine phosphokinase (p = 0.0129), new onset of atrial fibrillation (p = 0.0116), and use of dobutamine during intensive care stay (p = 0.0014). With this combination of clinical variables alone, using a survival probability partition value of 50%, the model had a sensitivity of 39% and a specificity of 96%, respectively, 84% overall correct classification. Predictive accuracy for death was 71%, compared to a predictive accuracy for survival of 85%. Diagnostic procedures performed after infarction were highly predictive in the individual case, but they could not improve accuracy of the statistical model. These data emphasize the importance of multivariate methods to find suitable predictors for outcome after acute myocardial infarction.
Assuntos
Infarto do Miocárdio/mortalidade , Adulto , Idoso , Fármacos Cardiovasculares/uso terapêutico , Terapia Combinada , Unidades de Cuidados Coronarianos , Eletrocardiografia/efeitos dos fármacos , Feminino , Seguimentos , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/reabilitação , Análise de Sobrevida , Taxa de Sobrevida , Fibrilação Ventricular/complicações , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/mortalidadeRESUMO
The aim of this prospective study was to analyze the technical feasibility, the success rate, and the special complications of percutaneous coronary interventions (PCIs) using a newly released 5 Fr guiding catheter with an inner diameter of 0.058". The study was performed in 150 consecutive patients subjected to coronary angioplasty. In 89% of the patients, the intervention was started with a 5 Fr catheter (JR4 or JL4); in 16 patients a 6 or 7 Fr catheter was used because of unstable clinical conditions according to the decision of the interventional cardiologist. In 12 out of 134 patients, the guiding catheter had to be changed during the intervention from 5 Fr to a 6 or 7 Fr catheter due to poor backup support. In 112 out of 118 patients, the intervention was successfully performed using a 5 Fr catheter (95%); in 12 out of 16 patients, after changing the guiding catheter, the overall success rate was 93%. In patients with type A and B lesions who were initially treated using a 5 Fr catheter, the procedural success rate was 100% (81 out of 81), whereas in patients with type C lesions the procedural success rate was 83% (43 out of 53; P = 0.000053, Fisher's exact test). Furthermore, in patients with a diameter stenosis < 90%, the procedural success rate was 100% (57 out of 57), whereas in patients with a diameter stenosis of 90%-100%, the procedural success rate was 87% (67 out of 77; P = 0.0050). Stent implantation was performed successfully in 24 patients (18%) using the 5 Fr guiding catheter. This study confirms that PCI was technically feasible using a 5 Fr guiding catheter in the majority of consecutive patients with a success rate of 95%. There were significant differences in the success rate depending on the lesion type and the diameter stenosis. Complications were very rare and were not related to the guiding catheter. Limitations of the 5 Fr guiding catheters arose mainly from a poor backup support in long lesions and severe stenosis. Cathet Cardiovasc Intervent 2001;53:308-312.
Assuntos
Angioplastia Coronária com Balão/instrumentação , Cateterismo/instrumentação , Doença das Coronárias/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do TratamentoRESUMO
BACKGROUND: A series of studies was performed to examine the ability of estradiol (E2) to protect endothelial cells from apoptosis. METHODS AND RESULTS: Light and transmission electron microscopy demonstrated typical features of apoptosis in human umbilical vein endothelial cells (HUVEC) exposed to tumor necrosis factor-alpha (TNF-alpha). Northern and Western blot analyses revealed induction of message and protein for the interleukin-1 beta converting enzyme (ICE), which has been shown to mediate apoptosis induced by TNF-alpha. Immunofluorescent staining of HUVEC colocalized ICE expression to apoptotic HUVEC. Direct cell counting demonstrated a significant decrease in total endothelial cell number after 24 hours of TNF-alpha exposure and a dose-dependent reversal of the effect of TNF-alpha with E2 treatment. This protective effect was abrogated by an estrogen-receptor antagonist. Fluorescence-activated cell sorting analysis revealed 39.3% apoptosis after 24 hours of TNF-alpha exposure. Treatment with E2 resulted in a 50% decrease in apoptosis. Similarly, viability assays revealed 35 +/- 4% cell death after TNF-alpha exposure. Simultaneous treatment with E2 resulted in a dose-dependent reduction of cell death to a minimum of 18 +/- 2%. The protective effect of E2 was nullified by a specific estrogen-receptor antagonist. CONCLUSIONS: E2 treatment resulted in a dose-dependent, receptor-mediated inhibition of TNF-alpha-induced endothelial cell apoptosis. These studies indicate that E2 may also serve a maintenance function in preventing endothelial cell death after noxious stimuli and suggest that the ICE pathway may mediate cytokine-induced apoptosis in endothelial cells. Preservation of endothelial integrity represents another mechanism that may account for the atheroprotective effect of estrogen.
Assuntos
Apoptose/fisiologia , Endotélio Vascular/fisiologia , Estradiol/farmacologia , Receptores de Estrogênio/fisiologia , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Virais , Northern Blotting , Western Blotting , Sobrevivência Celular/fisiologia , Células Cultivadas , Fragmentação do DNA , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Imunofluorescência , Humanos , Microscopia Eletrônica , Microscopia de Fluorescência , Microscopia de Contraste de Fase , Serpinas/metabolismoRESUMO
Human arterial smooth muscle cell (haSMC) proliferation is stimulated by platelet-derived growth factor (PDGF) release of human arterial endothelial cells (haEC) whereas transforming growth factor-beta(1) (TGF-beta(1)) secretion by haSMC promotes extracellular matrix formation. Inhibitory concepts with antisense oligonucleotides (ASO) against those growth factors might be promising, requiring, however, sufficient transfection efficacy. Thus, toxicity and efficacy of new transfection reagents were examined. MTT tests showed that high doses >1.6 microg/ml of the liposome Cytofectin GSV((R)) (CF) and the dendrimer SuperFect (SF) reduced mitochondrial activity of haEC after > or =4 h transfection whereas viability of haSMC was not influenced. DAC-30((R)) showed significant toxic effects on haEC and haSMC at each dose after > or =4 h and Lipofectin((R)) (LF) caused complete detachment of haEC and haSMC in medium containing 10% serum. Uptake studies demonstrated that 'naked' ASO were not incorporated intracellularly whereas transfection within CF or SF resulted in a strong cytoplasmic and nuclear labeling after 2-5 h. With DAC-30, only a slight cytoplasmic fluorescence was found. SF caused an unexpected stimulation of endothelial PDGF-AB synthesis. Thus, CF was favored for inhibition studies. ELISA, Western and Northern blotting showed a significant inhibition of endothelial PDGF-B and smooth muscle TGF-beta(1) mRNA expression and synthesis after transfection for 3-5 h using 0.1-1.0 microM ASO versus control oligonucleotides. We conclude that Cytofectin GSV is superior to the other transfection reagents, predominantly at haEC, showing an improved efficacy and less toxicity than the classical liposome Lipofectin. Cytofectin GSV might offer a promising tool for antisense strategies in the treatment of vascular disorders.
Assuntos
Indicadores e Reagentes/farmacologia , Indicadores e Reagentes/farmacocinética , Oligonucleotídeos/farmacocinética , Transfecção/métodos , Vasos Sanguíneos/citologia , Cápsulas , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fluoresceína-5-Isotiocianato , Substâncias de Crescimento/metabolismo , Humanos , Indicadores e Reagentes/efeitos adversos , Oligonucleotídeos Antissenso/administração & dosagem , Oligonucleotídeos Antissenso/farmacologia , Proteínas Proto-Oncogênicas c-sis/biossíntese , Proteínas Proto-Oncogênicas c-sis/genética , RNA Mensageiro/metabolismo , Fator de Crescimento Transformador beta/biossíntese , Fator de Crescimento Transformador beta/genéticaRESUMO
BACKGROUND: The mechanisms of the established atheroprotective effects of estrogen have not been entirely clarified. Recent data suggest that agents that hasten the recovery of the endothelium after denuding injury will deter the development of neointimal lesions. Because estrogen has been shown to exert angiogenic effects in vitro and in vivo, we performed a series of experiments to evaluate whether estrogen was capable of accelerating reendothelialization. METHODS AND RESULTS: Ovariectomized Sprague-Dawley rats received estrogen replacement therapy in the form of subcutaneously implanted pellets designed to release 1.5 or 5.0 mg 17 beta-estradiol over 30 days. Deendothelializing balloon injury was performed 1 week after pellet implantation, and animals were euthanatized after 1 week for evaluation of reendothelialization (Evans blue staining) or 2 weeks for evaluation of reendothelialization and neointimal formation. At both time points, the use of estradiol caused a dose-dependent increase in reendothelialization, which was measured as absolute area and percentage of area that is reendothelialized. Estradiol accelerated functional endothelial recovery, manifested as an increase in nitric oxide production. Neointimal thickening was also shown to be inhibited in a dose-dependent fashion. CONCLUSIONS: Estrogen accelerates functional endothelial recovery after barotraumatic deendothelializing injury. These findings, along with the recent demonstration of estrogen receptor expression by endothelial cells, suggest that the antiatherogenic action of estrogen may be mediated in part through direct effects on endothelial cells.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Estradiol/farmacologia , Cicatrização/efeitos dos fármacos , Angioplastia com Balão/efeitos adversos , Animais , Barotrauma/etiologia , Barotrauma/patologia , Artérias Carótidas/patologia , Lesões das Artérias Carótidas , Relação Dose-Resposta a Droga , Implantes de Medicamento , Fatores de Crescimento Endotelial/biossíntese , Endotélio Vascular/lesões , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Terapia de Reposição de Estrogênios , Feminino , Linfocinas/biossíntese , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Ovariectomia , Ratos , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
A series of experiments was performed to determine whether vascular endothelial growth factor (VEGF), in addition to its endothelial cell specific mitogenic activity, can also protect endothelial cells from toxin-induced programmed cell death. Apoptosis was induced in endothelial cell culture with tumor necrosis factor-alpha (TNF-alpha). Simultaneous exposure of endothelial cells to VEGF resulted in a dose dependent inhibition of apoptosis when evaluated by: (1) direct counting of cells with morphologic features of apoptosis after acridine orange staining; (2) analysis of DNA fragmentation by (a) agarose gel electrophoresis and (b) fluorescence activated cell sorting (FACS); and (3) viability assays dependent upon mitochondrial function. Induction of fibronectin and beta 3 integrin expression in endothelial cells by VEGF suggests that altered adhesion molecule expression may explain this survival effect.
Assuntos
Apoptose , Fatores de Crescimento Endotelial/farmacologia , Endotélio Vascular/efeitos dos fármacos , Linfocinas/farmacologia , Mitógenos/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Animais , Northern Blotting , Bovinos , Linhagem Celular , Sobrevivência Celular , Células Cultivadas , Fragmentação do DNA , Relação Dose-Resposta a Droga , Eletroforese em Gel de Ágar , Endotélio Vascular/citologia , Citometria de Fluxo , Humanos , Microscopia de Fluorescência , Transdução de Sinais , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
Endothelium-derived nitric oxide (NO) and its precursor L-arginine have been implied to promote angiogenesis, but little is known about the precise mechanism. The inhibition of endogenous NO formation by Nomega-nitro-L-arginine methyl ester (L-NAME) (1 mmol/L) but not its inactive enantiomer D-NAME (1 mmol/L) inhibited endothelial cell sprouting from the scratched edge of the cultured bovine aortic endothelial cell monolayer. Inhibition of endogenous NO release by L-NAME was confirmed by amperometric measurement using an NO-specific electrode. In the modified Boyden chamber, L-NAME (1 mmol/L) significantly inhibited endothelial cell migration, whereas L-NAME did not affect endothelial DNA synthesis as assessed by analysis of [3H]thymidine incorporation. We then examined alteration of endothelial cell adhesion molecule expression after the inhibition of NO by L-NAME in cultured human umbilical vein endothelial cells. In both normoxic and hypoxic conditions, L-NAME (1 mmol/L) inhibited surface expression of integrin alphavbeta3, which is an important integrin facilitating endothelial cell survival and angiogenesis. However, L-NAME did not affect the expression of platelet endothelial cell adhesion molecule-1, intercellular adhesion molecule-1, vascular endothelial adhesion molecule-1, gap junction protein connexin 43, and VE-cadherin, which have been reported to potentially affect angiogenesis. In summary, inhibition of endothelial NO synthase by L-NAME attenuated endothelial cell migration but not proliferation in vitro. Furthermore, endogenous endothelium-derived NO maintains the functional expression of integrin alphavbeta3, a mediator for endothelial migration, survival, and angiogenesis. Endothelium-derived NO, thus, may play an important role in mediating angiogenesis by supporting endothelial cell migration, at least partly, via an integrin-dependent mechanism.
Assuntos
Endotélio Vascular/citologia , Neovascularização Fisiológica , Óxido Nítrico Sintase/fisiologia , Óxido Nítrico/fisiologia , Animais , Antígenos CD , Aorta , Arginina/metabolismo , Caderinas/biossíntese , Bovinos , Hipóxia Celular , Movimento Celular , Células Cultivadas , Conexina 43/biossíntese , Endotélio Vascular/lesões , Endotélio Vascular/metabolismo , Citometria de Fluxo , Humanos , Molécula 1 de Adesão Intercelular/biossíntese , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase Tipo III , Molécula-1 de Adesão Celular Endotelial a Plaquetas/biossíntese , Receptores de Vitronectina/biossíntese , Estereoisomerismo , Veias Umbilicais , Molécula 1 de Adesão de Célula Vascular/biossínteseRESUMO
The case of a 30-year-old man with primary systemic amyloidosis is reported. Three months prior to admission the patient developed fever, night sweats, dyspnea, and bilateral ankle swelling. Recurrent left-sided pleural effusion led to further investigation when massive proteinuria with free monoclonal lambda chains in the urine became evident. Abdominal subcutaneous fat aspiration and renal biopsy confirmed the diagnosis of amyloidosis. Bone marrow biopsy and bone scan did not reveal multiple myeloma. Echocardiography showed a sparkling texture of the interventricular septum. Pulsed-wave Doppler recording of the left ventricular inflow profile showed the pattern of advanced cardiac amyloidosis consistent with markedly impaired diastolic heart function. Electrocardiogram-gated magnetic resonance imaging was carried out for noninvasive evaluation of cardiac function. The patient was started on repeated courses of melphalan, prednisone, and colchicine therapy. Despite increasing deterioration of renal function the therapy was tolerated quite well, and the patient is still alive 10 months after initial diagnosis. Although very rare in this age, primary systemic amyloidosis should be considered as a cause of pleural effusion, proteinuria, and congestive heart failure and should lead to further investigation.
Assuntos
Amiloidose/complicações , Insuficiência Cardíaca/etiologia , Síndrome Nefrótica/etiologia , Adulto , Idade de Início , Humanos , Masculino , Derrame Pleural/etiologiaRESUMO
Recently, vascular endothelial growth factor-C (VEGF-C or VEGF-2) was described as a specific ligand for the endothelial receptor tyrosine kinases VEGFR-2 and VEGFR-3. In vivo data, limited to constitutive overexpression in transgenic mice, have been interpreted as evidence that the growth-promoting effects of VEGF-C are restricted to development of the lymphatic vasculature. The current studies were designed to test the hypothesis that constitutive expression of VEGF-C in adult animals promotes angiogenesis. In vitro, VEGF-C exhibited a dose-dependent mitogenic and chemotactic effect on endothelial cells, particularly for microvascular endothelial cells (72% and 95% potency, respectively, compared with VEGF-A/VEGF-1). VEGF-C stimulated release of nitric oxide from endothelial cells and increased vascular permeability in the Miles assay; the latter effect was attenuated by pretreatment with the nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester. Both VEGFR-2 and VEGFR-3 receptors were shown to be expressed in human saphenous vein and internal mammary artery. The potential for VEGF-C to promote angiogenesis in vivo was then tested in a rabbit ischemic hindlimb model. Ten days after ligation of the external iliac artery, VEGF-C was administered as naked plasmid DNA (pcVEGF-C; 500 microg) from the polymer coating of an angioplasty balloon (n = 8 each) or as recombinant human protein (rhVEGF-C; 500 microg) by direct intra-arterial infusion. Physiological and anatomical assessments of angiogenesis 30 days later showed evidence of therapeutic angiogenesis for both pcVEGF-C and rhVEGF-C. Hindlimb blood pressure ratio (ischemic/normal) after pcVEGF-C increased to 0.83 +/- 0.03 after pcVEGF-C versus 0.59 +/- 0.04 (P < 0.005) in pGSVLacZ controls and to 0.76 +/- 0.04 after rhVEGF-C versus 0.58 +/- 0.03 (P < 0.01) in control rabbits receiving rabbit serum albumin. Doppler-derived iliac flow reserve was 2.7 +/- 0.1 versus 2.0 +/- 0.2 (P < 0.05) for pcVEGF-C versus LacZ controls and 2.9 +/- 0.3 versus 2.1 +/- 0.2 (P < 0.05) for rhVEGF-C versus albumin controls. Neovascularity was documented by angiography in vivo (angiographic scores: 0.85 +/- 0.05 versus 0.51 +/- 0.02 (P < 0.001) for plasmid DNA and 0.74 +/- 0.08 versus 0.53 +/- 0.03 (P < 0.05) for protein), and capillary density (per mm2) was measured at necropsy (252 +/- 12 versus 183 +/- 10 (P < 0.005) for plasmid DNA and 229 +/- 20 versus 164 +/- 20 (P < 0.05) for protein). In contrast to the results of gene targeting experiments, constitutive expression of VEGF-C in adult animals promotes angiogenesis in the setting of limb ischemia. VEGF-C and its receptors thus constitute an apparently redundant pathway for postnatal angiogenesis and may represent an alternative to VEGF-A for strategies of therapeutic angiogenesis in patients with limb and/or myocardial ischemia.