RESUMO
OBJECTIVE: Prostaglandin E1 (PGE-1) is a potent vasodilative agent which has been used to bridge patients with chronic heart failure listed for heart transplantation (HTX). In various experimental settings PGE-1 appears to stimulate angiogenesis by inducing vascular endothelial growth factor expression. This observational clinical study sought to investigate the angiogenic effects of PGE-1 in the failing human heart. METHODS: Neovascularization was investigated in 14 explanted hearts from patients with ischemic cardiomyopathy (ICMP) who had been bridged to HTX with PGE-1 (8+/-1 mg/kg/min, 97+/-75.6 days) and compared with 14 hearts who did not receive PGE-1 prior to HTX. In three sectional areas obtained from the left ventricular wall CD34, von Willebrand factor (vWf), nuclear Ki67 (MIB-1), and VEGF were quantified by immunohistochemistry to estimate capillary density and endothelial cell proliferation. Additionally, to investigate a possible angiogenic effect of PGE-1 in vitro, cultured human coronary artery smooth muscle cells (HCASMCs) were treated with PGE-1. RESULTS: PGE-1-treated patients had significantly more CD34- and vWf-positive cells in the subepicardium (both P<0.01), myocardium (both P<0.0001) and subendocardium (P<0.01 and P<0.001) as compared to the nonPGE-1 group. Proliferative endothelial activity expressed by the presence of MIB-1- and VEGF-positive cells (both P<0.0001 in all layers) was increased more than twofold. Addition of PGE-1 to HCASMCs in cell culture resulted in a significant increase in VEGF production (164.0+/-19.7 pg/10(5) cells/24 h, P<0.005) as compared to the control cell line (66.6+/-8.7 pg/10(5) cells/24 h, P<0.005). CONCLUSIONS: Our data demonstrate that PGE-1 is a potent stimulator of angiogenesis via upregulation of VEGF expression. The induction of therapeutic angiogenesis in patients with severe ICMP might explain the favorable clinical outcome in PGE-1 treated patients until HTX.
Assuntos
Alprostadil/farmacologia , Isquemia Miocárdica/fisiopatologia , Neovascularização Patológica/induzido quimicamente , Fatores de Transcrição , Adulto , Idoso , Antígenos CD34/metabolismo , Técnicas de Cultura de Células/métodos , Vasos Coronários/patologia , Proteínas de Ligação a DNA/metabolismo , Fatores de Crescimento Endotelial/metabolismo , Feminino , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Antígeno Ki-67/metabolismo , Linfocinas/metabolismo , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/efeitos dos fármacos , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Neovascularização Patológica/patologia , Neovascularização Patológica/fisiopatologia , Proteínas Nucleares/metabolismo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Fator de von Willebrand/metabolismoRESUMO
PPARgamma, a nuclear transcription factor, is expressed in various cells within the vasculature and in cardiomyocytes. It has been suggested that PPARgamma is involved in atherogenesis and in cardiac hypertrophy. Therefore, we sought to quantify PPARgamma mRNA in coronary arteries, the aorta and left ventricular specimens from patients with ischaemic (CHD) and dilated cardiomyopathy (CMP). Using real-time PCR, we were able to demonstrate the expression of PPARgamma in all of the human specimens. The lowest expression of PPARgamma was detected in the aorta specimens of both groups (this was set to one). In comparison, the expression in coronary arteries was 2.32-fold in CHD- and 3.78-fold in CMP specimens and in the left ventricle specimens, 2.12-fold in CHD- and 3.51-fold in CMP. Samples from CHD patients showed a higher expression of PPARgamma in all of the samples compared to those from CMP patients (aorta: 1.99-fold; coronary arteries: 1.35; left ventricles: 1.23). PPARgamma levels were not significantly correlated to CD 36 expression values in any group, suggesting that higher levels of PPARgamma are not principally due to increased PPARgamma expression in macrophages. This was confirmed by immunohistochemical analysis, which showed that PPARgamma is also located in the smooth muscle layer and in cardiomyocytes. In conclusion, our observations of increased PPAR mRNA expression in the coronary arteries and left ventricles from CHD and CMP patients suggest an important function of this nuclear receptor in the pathogenesis of heart disease.
Assuntos
Cardiomiopatia Dilatada/metabolismo , Isquemia Miocárdica/metabolismo , Receptores Citoplasmáticos e Nucleares/análise , Fatores de Transcrição/análise , Adulto , Idoso , Aorta/metabolismo , Antígenos CD36/metabolismo , Cardiomiopatia Dilatada/etiologia , Vasos Coronários/metabolismo , Proteínas de Ligação a DNA/análise , Proteínas de Ligação a DNA/genética , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/etiologia , Miocárdio/metabolismo , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Fatores de Transcrição/genéticaRESUMO
The objective of this study was to investigate the expression of the arylhydrocarbon receptor (AhR) and its partner AhR-nuclear translocator (ARNT) in left ventricle specimens from explanted hearts from patients with cardiomyopathy (CMP). Explanted hearts from 16 patients with ischemic (n=9, age 63+/-12 years) and dilative (n=7, age 54+/-12 years) CMP, undergoing heart transplantation were examined. Healthy donor hearts from five accident victims served as controls. As these donors were of younger age (32+/-11 years), additionally, donor hearts from three older accident victims (age 48+/-15 years) without clinical symptoms but with signs of ventricular hyperthrophy (n=1) or atherosclerotic lesions (n=2) were included ("pathological controls"). Expression of AhR and ARNT was analyzed using semi-quantitative immunohistochemistry, and in selected samples, Western blot- and reverse-transcription polymerase chain reaction analysis were performed to confirm AhR and ARNT expression. Immunohistological analysis revealed weak to intermediate staining of anti-AhR in control, but weak to intense staining in CMP- and "pathologic control" specimens, indicating significantly increased AhR levels in the diseased heart. Moreover, in CMP specimens, the percentage of AhR-positive cells was strongly increased. Higher anti-AhR staining was also seen in two atherosclerotic "pathologic control" specimens. In all groups, the intensity of anti-ARNT staining was more pronounced than AhR staining, but significant differences or any age-related alterations were not observed. In conclusion, the increased cellular content of AhR in left ventricular specimens from CMP patients suggests a role for AhR in heart disease.
Assuntos
Cardiomiopatias/metabolismo , Proteínas de Ligação a DNA , Receptores de Hidrocarboneto Arílico/metabolismo , Fatores de Transcrição/metabolismo , Adulto , Translocador Nuclear Receptor Aril Hidrocarboneto , Western Blotting , Cardiomiopatias/patologia , Contagem de Células , Primers do DNA/química , Feminino , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genéticaRESUMO
In the present study, we sought to investigate whether elevated serum levels of homocysteine (Hcy), predisposing to endothelial dysfunction during progression of atherosclerosis, were paralleled by increased Hcy concentrations in human coronary arteries. Paraffin sections of coronary arteries were obtained from explanted hearts of cardiac transplant recipients suffering from coronary artery disease (CAD, n=32, mean age=56.6+/-6.8), and from heart donors where transplantation was not performed due to organization-related circumstances (Co, n=6, mean age 25.0+/-10.6), and characterized immunohistochemically for Hcy, CD68, and smooth muscle alpha-actin. Although the CAD group presented with high serum Hcy levels (27.7+/-12.8 micromol/l), the media and intimal layers containing the endothelium showed the lowest enrichment of Hcy (media: 20.8+/-4.4%; intima: 6.1+/-2.3%). Surprisingly, the control group revealed an extensive Hcy enrichment, co-localizing with vascular smooth cells (media: 32.3+/-14.0%; intima: 7.0+/-2.0%). In conclusion, we have provided evidence for a reverse relation between Hcy serum concentration and enrichment of Hcy in coronary arteries of patients with severe CAD, suggesting that Hcy is not likely to be involved directly in atheromatosis development of coronary arteries.
Assuntos
Doença da Artéria Coronariana/patologia , Vasos Coronários/metabolismo , Homocisteína/análise , Estudos de Casos e Controles , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/etiologia , Feminino , Transplante de Coração , Homocisteína/sangue , Humanos , Imuno-Histoquímica , Interleucina-6/análise , Interleucina-6/metabolismo , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismoRESUMO
New evidence suggests that Prostaglandin E1 (PGE-1) stimulates myocardial angiogenesis in human chronic ischemic myocardium. We sought to investigate whether PGE-1 may participate in the process of neoangiogenesis within the myocardial infarct scar. Neovascularization was investigated in 14 explanted hearts from patients with ischemic cardiomyopathy, who had been bridged to heart transplantation (HTX) with PGE-1 and compared with 14 hearts from patients who did not receive PGE-1 prior to HTX. In transmural sections obtained from the left ventricular wall and containing myocardial scar tissue, CD34 and vascular endothelial growth factor (VEGF) were quantified immunohistochemically to estimate capillary density and amount of angiogenesis. Additionally, to assess the hypoxic state of myocardium of the infarct border zone, hypoxia inducible factor 1-alpha (HIF-1alpha) was determined by immunohistochemistry and quantified by means of planimetric analysis. PGE-1-treated patients had significantly more CD34-and VEGF-positive cells in infarct areas as compared to nonPGE-1 group, respectively (CD34: 116.7 +/- 5.9 vs. 45.1 +/- 5.2 capillary profiles/mm(2), P < 0.001, and VEGF: 48.3 +/- 4.9 vs. 22.9 +/- 4.7 capillary profiles/mm(2)). HIF-1alpha enrichment (in %) as well as staining intensity (in estimated units (eU)) was significantly decreased in PGE-1-treated as compared to non-treated controls (enrichment: 11.3 +/- 2.5% vs. 19.4 +/- 4.36%; staining intensity: 0.95 +/- 0.3 vs. 1.97 +/- 0.44 eU). Our data demonstrate that PGE-1 stimulates neoangiogenesis in infarct areas adjacent to viable myocardium, via upregulation of VEGF expression. The induction of therapeutic angiogenesis along with the improved hypoxic state of chronic ischemic myocardial tissue might explain the favorable clinical outcome in PGE-1 treated patients.
Assuntos
Alprostadil/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Isquemia Miocárdica/tratamento farmacológico , Neovascularização Fisiológica/efeitos dos fármacos , Vasodilatadores/uso terapêutico , Antígenos CD34/metabolismo , Biomarcadores , Pressão Sanguínea/fisiologia , Capilares/patologia , Feminino , Transplante de Coração , Humanos , Hipóxia/metabolismo , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Isquemia Miocárdica/patologia , Artéria Pulmonar/fisiologia , Pressão Propulsora Pulmonar/fisiologia , Estimulação Química , Fatores de Transcrição/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Prostaglandin E1 (PGE-1) treatment has proved to stimulate angiogenesis in vital non-infarcted myocardium of patients with ischemic cardiomyopathy (ICMP). We investigated infarcted myocardial tissue for a possible angiogenic response to PGE-1. Neovascularization was investigated in infarcted areas of 12 hearts explanted from patients with ICMP who had been treated with PGE-1 before heart transplantation (HTX). In transmural sections containing myocardial scar tissue, CD34 and VEGF were immunohistochemically quantified to estimate capillary density and the extent of angiogenesis. To investigate a possible effect of PGE-1 on collagen turnover, the collagen content was determined in myocardial scar tissue by assessing the intensity of the area positively stained with sirius red. PGE-1-treated patients had significantly more CD34- and VEGF-positive cells in infarcted areas, and showed a significant reduction in collagen content as compared with the non-PGE-1 group (CD34: 120.3 +/- 6.1 vs. 47.7 +/- 6.1 capillary profiles/mm2; VEGF: 52.8 +/- 5.6 vs. 24.0 +/- 4.8 capillary profiles/mm2, and collagen content: 2.18 +/- 0.4 eU vs. 3.59 +/- 0.38 eU). Our data demonstrate that PGE-1 stimulates angiogenesis by upregulating VEGF expression, and reduces fibrosis in cardiac scar tissue of ischemic origin. The induction of therapeutic angiogenesis in vital and at sites of putative dead myocardial scar tissue, along with the hemodynamic improvement in patients with severe ICMP, might explain the favorable clinical outcome in PGE-1-treated patients before HTX.