RESUMO
The rate of the remodeling of the arterialized saphenous vein conduit limits the outcomes of coronary artery bypass graft surgery (CABG), which may be influenced by endothelial dysfunction. We tested the hypothesis that high stretch (HS) induces human saphenous vein endothelial cell (hSVEC) dysfunction and examined candidate underlying mechanisms. Our results showed that in vitro HS reduces NO bioavailability, increases inflammatory adhesion molecule expression (E-selectin and VCAM1) and THP-1 cell adhesion. HS decreases F-actin in hSVECs, but not in human arterial endothelial cells, and is accompanied by G-actin and cofilin's nuclear shuttling and increased reactive oxidative species (ROS). Pre-treatment with the broad-acting antioxidant N-acetylcysteine (NAC) supported this observation and diminished stretch-induced actin remodeling and inflammatory adhesive molecule expression. Altogether, we provide evidence that increased oxidative stress and actin cytoskeleton remodeling play a role in HS-induced saphenous vein endothelial cell dysfunction, which may contribute to predisposing saphenous vein graft to failure.
Assuntos
Actinas/metabolismo , Células Endoteliais/metabolismo , Estresse Oxidativo , Veia Safena/metabolismo , Estresse Mecânico , Humanos , Espécies Reativas de Oxigênio/metabolismo , Células THP-1RESUMO
La proteína chaperona Calreticulina (CRT), ha sido identificada en retículo endoplásmico (RE) y últimamente en la matriz extracelular (MEC) de predentina y arterias, atribuyéndole diferentes funciones extracelulares entre las que destacan la adhesión celular, regulación de la MEC y prevención en la formación de trombos. El objetivo del estudio fue identificar la presencia de CRT en MEC de vena safena parva. Se extrajo una muestra de vena safena parva de un espécimen masculino y luego fue procesada por medios histológicos e inmunohistoquímicos para identificar su presencia. Mediante técnicas de inmunohistoquímica se pudo evidenciar la presencia de CRT en la MEC de la adventicia de vena safena parva. La presencia de CRT en MEC de safena parva orienta a que CRT tienen funciones de tipo extracelular en esta localización, pero es necesario realizar estudios más precisos para dilucidar sus principales funciones en la zona.
Calreticulin (CRT) protein, has been identified in the endoplasmic reticulum (ER) and lately in the extracellular matrix (ECM) of predentine and arteries. It is responsible for different extracellular functions, such as cell adhesion, ECM regulation, and the prevention of thrombosis. The aim was to identify the presence of CRT in ECM of small saphenous vein. A sample of small saphenous vein from a male specimen was extracted and then processed by histological and immunohistochemical assays to identify its presence. The presence of CRT in the ECM of the small saphenous vein was observed by immunohistochemical techniques. The presence of CRT in the small saphenous vein ECM, indicates that CRT have extracellular functions in this area, however, more precise studies are necessary to determine its main functions.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Veia Safena/metabolismo , Calreticulina/metabolismo , Imuno-HistoquímicaRESUMO
OBJECTIVES: In varicose veins, vascular smooth muscle cells (VSMCs) often shows phenotypic transition and abnormal proliferation and migration. Evidence suggests the FOXC2-Notch pathway may be involved in the pathogenesis of varicose veins. Here, this study aimed to explore the role of long non-coding RNA FOXC2-AS1 (FOXC2 antisense RNA 1) in phenotypic transition, proliferation, and migration of varicose vein-derived VSMCs and to explore whether the FOXC2-Notch pathway was involved in this process. METHODS: The effect of FOXC2-AS1 on the proliferation and migration of human great saphenous vein smooth muscle cells (SV-SMCs) was analyzed using MTT assay and Transwell migration assay, respectively. The levels of contractile marker SM22α and synthetic marker osteopontin were measured by immunohistochemistry and Western blot to assess the phenotypic transition. RESULTS: The human varicose veins showed thickened intima, media and adventitia layers, increased synthetic VSMCs, as well as upregulated FOXC2-AS1 and FOXC2 expression. In vitro assays showed that FOXC2-AS1 overexpression promoted phenotypic transition, proliferation, and migration of SV-SMCs. However, the effect of FOXC2-AS1 overexpression could be abrogated by both FOXC2 silencing and the Notch signaling inhibitor FLI-06. Furthermore, FOXC2-AS1 overexpression activated the Notch pathway by upregulating FOXC2. CONCLUSION: FOXC2-AS1 overexpression promotes phenotypic transition, proliferation, and migration of SV-SMCs, at least partially, by activating the FOXC2-Notch pathway.
Assuntos
Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Fatores de Transcrição Forkhead/metabolismo , Miócitos de Músculo Liso/metabolismo , Veia Safena/metabolismo , Células Cultivadas , Humanos , Miócitos de Músculo Liso/patologia , Fenótipo , Veia Safena/patologia , Transdução de Sinais , Regulação para CimaRESUMO
OBJECTIVES: In varicose veins, vascular smooth muscle cells (VSMCs) often shows phenotypic transition and abnormal proliferation and migration. Evidence suggests the FOXC2-Notch pathway may be involved in the pathogenesis of varicose veins. Here, this study aimed to explore the role of long non-coding RNA FOXC2-AS1 (FOXC2 antisense RNA 1) in phenotypic transition, proliferation, and migration of varicose vein-derived VSMCs and to explore whether the FOXC2-Notch pathway was involved in this process. METHODS: The effect of FOXC2-AS1 on the proliferation and migration of human great saphenous vein smooth muscle cells (SV-SMCs) was analyzed using MTT assay and Transwell migration assay, respectively. The levels of contractile marker SM22α and synthetic marker osteopontin were measured by immunohistochemistry and Western blot to assess the phenotypic transition. RESULTS: The human varicose veins showed thickened intima, media and adventitia layers, increased synthetic VSMCs, as well as upregulated FOXC2-AS1 and FOXC2 expression. In vitro assays showed that FOXC2-AS1 overexpression promoted phenotypic transition, proliferation, and migration of SV-SMCs. However, the effect of FOXC2-AS1 overexpression could be abrogated by both FOXC2 silencing and the Notch signaling inhibitor FLI-06. Furthermore, FOXC2-AS1 overexpression activated the Notch pathway by upregulating FOXC2. CONCLUSION: FOXC2-AS1 overexpression promotes phenotypic transition, proliferation, and migration of SV-SMCs, at least partially, by activating the FOXC2-Notch pathway.
Assuntos
Humanos , Veia Safena/metabolismo , Movimento Celular/fisiologia , Miócitos de Músculo Liso/metabolismo , Proliferação de Células/fisiologia , Fatores de Transcrição Forkhead/metabolismo , Fenótipo , Veia Safena/patologia , Transdução de Sinais , Regulação para Cima , Células Cultivadas , Miócitos de Músculo Liso/patologiaRESUMO
Recently, H2O2 has been identified as the endothelium-dependent hyperpolarizing factor (EDHF), which mediates flow-induced dilation in human coronary arteries. Neuronal nitric oxide synthase (nNOS) is expressed in the cardiovascular system and, besides NO, generates H2O2 The role of nNOS-derived H2O2 in human vessels is so far unknown. The present study was aimed at investigating the relevance of nNOS/H2O2 signaling in the human internal mammary artery (IMA) and saphenous vein (SV), the major conduits used in coronary artery bypass grafting. In the IMA, but not in the SV, ACh (acetylcholine)-induced vasodilatation was decreased by selective nNOS inhibition with TRIM or Inhibitor 1, and by catalase, which specifically decomposes H2O2 Superoxide dismutase (SOD), which generates H2O2 from superoxide, decreased the vasodilator effect of ACh on SV. In the IMA, SOD diminished phenylephrine-induced contraction in endothelium-containing, but not in endothelium-denuded vessels. Importantly, while exogenous H2O2 produced vasodilatation in IMA, it constricted SV. ACh increased H2O2 production in both sets of vessels. In the IMA, the increase in H2O2 was inhibited by catalase and nNOS blockade. In SV, H2O2 production was abolished by catalase and reduced by nNOS inhibition. Immunofluorescence experiments showed the presence of nNOS in the vascular endothelium and smooth muscle cells of both the IMA and SV. Together, our results clearly show that H2O2 induced endothelium-dependent vascular relaxation in the IMA, whereas, in the SV, H2O2 was a vasoconstrictor. Thus, H2O2 produced in the coronary circulation may contribute to the susceptibility to accelerated atherosclerosis and progressive failure of the SV used as autogenous graft in coronary bypass surgery.
Assuntos
Vasos Coronários/metabolismo , Peróxido de Hidrogênio/metabolismo , Artéria Torácica Interna/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Veia Safena/metabolismo , Idoso , Ponte de Artéria Coronária , Vasos Coronários/cirurgia , Feminino , Humanos , Masculino , Artéria Torácica Interna/cirurgia , Pessoa de Meia-Idade , Músculo Liso Vascular/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/genética , Veia Safena/cirurgiaRESUMO
PURPOSE: To develop an ex vivo model for the analysis of macroscopic, histological and immunohistochemical changes after experimental endovenous laser ablation (EVLA) of the great saphenous vein (GSV). METHODS: We describe a model produced with glass tubes and introducer sheaths to mimic the physiological conditions of EVLA procedures, such as tumescence and blood flow. A pilot study was conducted to evaluate an ex vivo procedure of EVLA of an incompetent GSV segment using a 1470-nm radial fiber diode laser (7 W power) and an automatic pull-back device. The vein segment was analyzed macroscopically and by hematoxylin & eosin staining, elastic fiber histochemistry, Gomori's trichrome staining, and alpha-smooth muscle actin immunohistochemistry. RESULTS: No perforations were observed macroscopically. No muscle cell adhesion was observed in the central part of the ablated vein, showing tissue disruption. There was low labeling for elastic fibers, disruption of muscle fibers, and a reduced expression of the specific marker for this cell type. CONCLUSION: This ex vivo endovenous laser ablation model is a low cost alternative to in vivo experiments, providing standardized experimental conditions.
Assuntos
Terapia a Laser/métodos , Lasers Semicondutores/uso terapêutico , Músculo Liso Vascular/metabolismo , Veia Safena/cirurgia , Humanos , Modelos Biológicos , Projetos Piloto , Reprodutibilidade dos Testes , Veia Safena/metabolismo , Veia Safena/patologia , Resultado do Tratamento , Varizes/metabolismo , Varizes/patologia , Varizes/cirurgiaRESUMO
ABSTRACT PURPOSE: To develop an ex vivo model for the analysis of macroscopic, histological and immunohistochemical changes after experimental endovenous laser ablation (EVLA) of the great saphenous vein (GSV). METHODS: We describe a model produced with glass tubes and introducer sheaths to mimic the physiological conditions of EVLA procedures, such as tumescence and blood flow. A pilot study was conducted to evaluate an ex vivo procedure of EVLA of an incompetent GSV segment using a 1470-nm radial fiber diode laser (7 W power) and an automatic pull-back device. The vein segment was analyzed macroscopically and by hematoxylin & eosin staining, elastic fiber histochemistry, Gomori's trichrome staining, and alpha-smooth muscle actin immunohistochemistry. RESULTS: No perforations were observed macroscopically. No muscle cell adhesion was observed in the central part of the ablated vein, showing tissue disruption. There was low labeling for elastic fibers, disruption of muscle fibers, and a reduced expression of the specific marker for this cell type. CONCLUSION: This ex vivo endovenous laser ablation model is a low cost alternative to in vivo experiments, providing standardized experimental conditions.
Assuntos
Humanos , Veia Safena/cirurgia , Terapia a Laser/métodos , Lasers Semicondutores/uso terapêutico , Músculo Liso Vascular/metabolismo , Veia Safena/metabolismo , Veia Safena/patologia , Varizes/cirurgia , Varizes/metabolismo , Varizes/patologia , Projetos Piloto , Reprodutibilidade dos Testes , Resultado do Tratamento , Modelos BiológicosRESUMO
OBJECTIVE: This study was carried out to determine high pressure and pulsatile flow perfusion effects on human saphenous vein (HSV) segments obtained from diabetic and non-diabetic patients. METHODS: The veins were perfused with oxygenated Krebs solution for 3 h, with a pulsatile flow rate of 100 mL/min and pressures of 250 × 200 or 300 × 250 mmHg. After perfusion, veins were studied by light microscopy; nitric oxide synthase (NOS) isoforms, CD34 and nitrotyrosine immunohistochemistry and tissue nitrite/nitrate (NO(x)) and malondialdehyde (MDA) quantification. RESULTS: Light microscopy revealed endothelial denuding areas in all HSV segments subjected to 300 × 250 mmHg perfusion pressure, but the luminal area was similar. The percentage of luminal perimeter covered by endothelium decreased as perfusion pressures increased, and significant differences were observed between groups. The endothelial nitric oxide synthase (eNOS) isoform immunostaining decreased significantly in diabetic patients' veins independent of the perfusion pressure levels. The inducible NOS (iNOS), neuronal NOS (nNOS) and nitrotyrosine immunostaining were similar. Significant CD34 differences were observed between the diabetic 300 × 250 mmHg perfusion pressure group and the non-diabetic control group. Tissue nitrite/nitrate and MDA were not different among groups. CONCLUSIONS: Pulsatile flow and elevated pressures for 3 h caused morphological changes and decreased the eNOS expression in the diabetic patients' veins.
Assuntos
Angiopatias Diabéticas/fisiopatologia , Regulação para Baixo , Endotélio Vascular/fisiopatologia , Hipertensão/complicações , Óxido Nítrico Sintase Tipo III/metabolismo , Veias/fisiopatologia , Idoso , Antígenos CD34/metabolismo , Angiopatias Diabéticas/complicações , Angiopatias Diabéticas/metabolismo , Angiopatias Diabéticas/patologia , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Feminino , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Perfusão , Pressão/efeitos adversos , Fluxo Pulsátil , Veia Safena/metabolismo , Veia Safena/patologia , Veia Safena/fisiopatologia , Fumar/efeitos adversos , Veias/metabolismo , Veias/patologiaRESUMO
Although the vasorelaxing effects of testosterone (T) and various androgen metabolites have been observed in a variety of blood vessels and species, previous studies have not systematically compared the vasorelaxing effects of androgen metabolites in different vascular beds within the same species. Therefore, we studied the vasorelaxing effects of T and its 5-reduced metabolites (5α- and 5ß-DHT) on KCl-induced contractions of the canine left coronary artery, femoral artery and saphenous vein, using standard isometric recordings. KCl contractions were inhibited by each androgen in a concentration-dependent manner from 1.8 to 310µM. Vascular sensitivity and efficacy were expressed as inhibitory concentration 50 (IC50) and maximal relaxation (R(max)), respectively. The coronary artery was significantly more sensitive to androgen-induced vasorelaxation than the saphenous vein or femoral artery. These vasorelaxing responses were unaffected by an antiandrogen (Flutamide) or the sulfhydryl reagent, N-ethylmaleimide, suggesting a nongenomic mechanism independent of signaling mediated by the androgen receptor or G proteins. Concentration-response curves were unchanged in endothelium-denuded preparations; thus, the endothelium appears to have no role in androgen-induced vasorelaxation. 5ß-DHT was the most potent androgen in both coronary and femoral artery, but all three androgens were equipotent in the saphenous vein. It is concluded that: 1) significant regional differences exist in vasorelaxing effects of androgen metabolites in the canine vasculature; 2) structural differences in these androgens determine their vasorelaxing efficacy; and 3) regional differences in androgen-induced vasorelaxation may account for some of the conflicting findings reported on the vasorelaxing effects of the androgens.
Assuntos
Androgênios/metabolismo , Vasos Sanguíneos/metabolismo , Di-Hidrotestosterona/metabolismo , Testosterona/metabolismo , Vasodilatação , Vasodilatadores/metabolismo , Antagonistas de Androgênios/farmacologia , Androgênios/química , Animais , Vasos Sanguíneos/efeitos dos fármacos , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/metabolismo , Di-Hidrotestosterona/antagonistas & inibidores , Di-Hidrotestosterona/química , Cães , Etilmaleimida/farmacologia , Artéria Femoral/efeitos dos fármacos , Artéria Femoral/metabolismo , Flutamida/farmacologia , Técnicas In Vitro , Masculino , Concentração Osmolar , Reprodutibilidade dos Testes , Veia Safena/efeitos dos fármacos , Veia Safena/metabolismo , Estereoisomerismo , Reagentes de Sulfidrila/farmacologia , Testosterona/antagonistas & inibidores , Vasodilatação/efeitos dos fármacos , Vasodilatadores/antagonistas & inibidores , Vasodilatadores/químicaRESUMO
Nowadays, the great saphenous vein is the vascular conduit that is most frequently employed in coronary and peripheral revascularization surgery. It is known that saphenous vein bypass grafts have shorter patency than arterial ones, partly because the wall of the normal saphenous vein has different structural and functional characteristics. The features of this vein can be affected by the large distention pressures it is submitted to during its preparation and insertion into the arterial system. Indeed, a vein graft is subjected to considerable changes in hemodynamic forces upon implantation into the arterial circulation, since it is transplanted from a non-pulsatile, low-pressure, low-flow environment with minimal shear stress to a highpressure system with pulsatile flow, where it undergoes cyclic strain and elevated shear. These changes can be responsible for functional and morphological alterations in the vessel wall, culminating in intima hyperproliferation and atherosclerotic degeneration, which contribute to early graft thrombosis. This review has followed a predetermined strategy for updating information on the human saphenous vein (HSV). Besides presenting the aspects relative to the basic pharmacology, this text also includes surgical aspects concerning HSV harvesting, the possible effects of the major groups of cardiovascular drugs on the HSV, and finally the interference of major cardiovascular diseases in the vascular reactivity of the HSV.