Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000012804.63152.60
F. Böhm, G. Ahlborg, B. Johansson, L. Hansson, J. Pernow
Endothelin (ET)-1 causes vasoconstriction via ETA and ETB receptors located on vascular smooth muscle cells and vasodilatation via ETB receptors on endothelial cells. Studies in vitro indicate an upregulation of ETB receptors in atherosclerosis. The present study investigated the vascular effects evoked by endogenous ET-1 in atherosclerotic patients. Forearm blood flow (FBF) was measured with venous occlusion plethysmography in 10 patients with atherosclerosis and in 10 healthy control subjects during intra-arterial infusion of selective ET receptor antagonists. The ETB receptor antagonist BQ788 evoked a significant increase in FBF (31±13%) in the patients, whereas a 20±9% reduction was observed in the control subjects. The ETA receptor antagonist BQ123 combined with BQ788 evoked a marked increase in FBF (102±25%) in the patients compared with no effect in the control subjects (−3±9%, P <0.001 versus patients). The ETA receptor antagonist BQ123 increased FBF to a similar degree in patients (39±11%) as in control subjects (41±11%). The increase in FBF evoked by selective ETA receptor blockade was significantly (P <0.05) less than that evoked by combined ETA/ETB receptor blockade in the atherosclerotic patients. These observations suggest an enhanced ET-1–mediated vascular tone in atherosclerotic patients, which is at least partly due to increased ETB-mediated vasoconstriction.
{"title":"Combined Endothelin Receptor Blockade Evokes Enhanced Vasodilatation in Patients With Atherosclerosis","authors":"F. Böhm, G. Ahlborg, B. Johansson, L. Hansson, J. Pernow","doi":"10.1161/01.ATV.0000012804.63152.60","DOIUrl":"https://doi.org/10.1161/01.ATV.0000012804.63152.60","url":null,"abstract":"Endothelin (ET)-1 causes vasoconstriction via ETA and ETB receptors located on vascular smooth muscle cells and vasodilatation via ETB receptors on endothelial cells. Studies in vitro indicate an upregulation of ETB receptors in atherosclerosis. The present study investigated the vascular effects evoked by endogenous ET-1 in atherosclerotic patients. Forearm blood flow (FBF) was measured with venous occlusion plethysmography in 10 patients with atherosclerosis and in 10 healthy control subjects during intra-arterial infusion of selective ET receptor antagonists. The ETB receptor antagonist BQ788 evoked a significant increase in FBF (31±13%) in the patients, whereas a 20±9% reduction was observed in the control subjects. The ETA receptor antagonist BQ123 combined with BQ788 evoked a marked increase in FBF (102±25%) in the patients compared with no effect in the control subjects (−3±9%, P <0.001 versus patients). The ETA receptor antagonist BQ123 increased FBF to a similar degree in patients (39±11%) as in control subjects (41±11%). The increase in FBF evoked by selective ETA receptor blockade was significantly (P <0.05) less than that evoked by combined ETA/ETB receptor blockade in the atherosclerotic patients. These observations suggest an enhanced ET-1–mediated vascular tone in atherosclerotic patients, which is at least partly due to increased ETB-mediated vasoconstriction.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89898105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000014221.30108.08
M. Silverman, R. Tumuluri, Mishel Davis, Gladys E. Lopez, J. Rosenbaum, P. Lelkes
Elevated plasma homocysteine is an independent risk factor for atherosclerosis. We hypothesized that homocysteine enhances monocyte/human aortic endothelial cell (HAEC) interactions, a pivotal early event in atherogenesis, by upregulating endothelial adhesion molecules. After incubation of cultured HAECs with reduced dl-homocysteine for up to 24 hours, adhesion of human monocytes to homocysteine-stimulated HAECs was significantly upregulated in a time- and dose-dependent fashion. Pretreatment of HAECs with 100 &mgr;mol/L homocysteine caused a 4.5-fold increase in the adhesion of normal human monocytes (P <0.001). Similarly, adhesion of monocytic U937 cells was maximally elevated by 3.5-fold at 100 &mgr;mol/L homocysteine (P <0.001). In support of our hypothesis, vascular cell adhesion molecule (VCAM)-1 mRNA expression increased 5-fold in HAECs after 3 hours of treatment with 100 &mgr; mol/L homocysteine, as assessed by quantitative reverse transcription– polymerase chain reaction. Neutralizing antibody studies confirmed the involvement of VCAM-1 in mediating monocyte adhesion to homocysteine-stimulated HAECs. Coincubation of HAECs with homocysteine and tumor necrosis factor-&agr; synergistically elevated monocyte adhesion as well as VCAM-1 protein expression, with the latter evaluated by flow cytometry. Preincubation of HAECs with cyclooxygenase inhibitors completely abrogated homocysteine-induced monocyte adhesion, whereas scavenging reactive oxygen species and the elevation of NO caused partial inhibition only. These data support the notion that the proinflammatory effects of homocysteine may have important implications in atherogenesis.
{"title":"Homocysteine Upregulates Vascular Cell Adhesion Molecule-1 Expression in Cultured Human Aortic Endothelial Cells and Enhances Monocyte Adhesion","authors":"M. Silverman, R. Tumuluri, Mishel Davis, Gladys E. Lopez, J. Rosenbaum, P. Lelkes","doi":"10.1161/01.ATV.0000014221.30108.08","DOIUrl":"https://doi.org/10.1161/01.ATV.0000014221.30108.08","url":null,"abstract":"Elevated plasma homocysteine is an independent risk factor for atherosclerosis. We hypothesized that homocysteine enhances monocyte/human aortic endothelial cell (HAEC) interactions, a pivotal early event in atherogenesis, by upregulating endothelial adhesion molecules. After incubation of cultured HAECs with reduced dl-homocysteine for up to 24 hours, adhesion of human monocytes to homocysteine-stimulated HAECs was significantly upregulated in a time- and dose-dependent fashion. Pretreatment of HAECs with 100 &mgr;mol/L homocysteine caused a 4.5-fold increase in the adhesion of normal human monocytes (P <0.001). Similarly, adhesion of monocytic U937 cells was maximally elevated by 3.5-fold at 100 &mgr;mol/L homocysteine (P <0.001). In support of our hypothesis, vascular cell adhesion molecule (VCAM)-1 mRNA expression increased 5-fold in HAECs after 3 hours of treatment with 100 &mgr; mol/L homocysteine, as assessed by quantitative reverse transcription– polymerase chain reaction. Neutralizing antibody studies confirmed the involvement of VCAM-1 in mediating monocyte adhesion to homocysteine-stimulated HAECs. Coincubation of HAECs with homocysteine and tumor necrosis factor-&agr; synergistically elevated monocyte adhesion as well as VCAM-1 protein expression, with the latter evaluated by flow cytometry. Preincubation of HAECs with cyclooxygenase inhibitors completely abrogated homocysteine-induced monocyte adhesion, whereas scavenging reactive oxygen species and the elevation of NO caused partial inhibition only. These data support the notion that the proinflammatory effects of homocysteine may have important implications in atherogenesis.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74722612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000013023.11297.B2
N. Fournier, A. Cogny, V. Atger, D. Pastier, D. Goudounèche, A. Nicoletti, N. Moatti, J. Chambaz, J. Paul, A. Kalopissis
Overexpression of human apolipoprotein A-II (hapo A-II) in transgenic mice (hAIItg mice) induced marked hypertriglyceridemia and low levels of plasma high density lipoprotein (HDL) with a high hapo A-II content. We sought to determine whether cholesterol efflux to plasma and HDL from these mice would be affected. In the Fu5AH cell system, plasma from hAIItg mice induced a markedly lower cholesterol efflux than did control plasma, in accordance with the dependence of efflux on HDL concentration. Moreover, HDLs from hAIItg mice were less effective acceptors than were control HDLs. In the J774 macrophage cell system, pretreatment with cAMP, which upregulates ATP binding cassette transporter 1, induced a marked increase in the efflux to hAIItg plasma as well as to purified hapo A-I and hapo A-II, whereas it had no effect on cholesterol efflux to control plasma. A strong positive correlation was established between percent cAMP stimulation of efflux and plasma hapo A-II concentration. The cAMP stimulation of efflux to hAIItg mouse plasma may be linked to the presence of pre-&bgr; migrating HDL containing hapo A-II. Thus, despite lower HDL and apolipoprotein A-I contents, the increased ability of plasma from hAIItg mice to extract cholesterol from macrophage-like cells may have an antiatherogenic influence.
在转基因小鼠(hAIItg小鼠)中，人载脂蛋白a - ii (hapo a - ii)的过度表达诱导了显著的高甘油三酯血症和低水平的血浆高密度脂蛋白(HDL)(高hapo a - ii含量)。我们试图确定这些小鼠的血浆和高密度脂蛋白胆固醇外排是否会受到影响。在Fu5AH细胞系统中，来自hAIItg小鼠的血浆诱导的胆固醇外排明显低于对照血浆，这与外排对HDL浓度的依赖性一致。此外，来自hAIItg小鼠的hdl受体不如对照hdl受体有效。在J774巨噬细胞系统中，预处理cAMP可上调ATP结合盒转运蛋白1，诱导haitg血浆外排明显增加，并纯化hapo a - i和hapo a - ii，而对控制血浆的胆固醇外排无影响。外排cAMP刺激百分比与血浆hapo A- ii浓度呈正相关。cAMP对小鼠血浆外排的刺激可能与pre- bgr的存在有关。迁移HDL含有hapo A-II。因此，尽管高密度脂蛋白和载脂蛋白A-I含量较低，但hAIItg小鼠血浆从巨噬细胞样细胞中提取胆固醇的能力增加可能具有抗动脉粥样硬化的作用。
{"title":"Opposite Effects of Plasma From Human Apolipoprotein A-II Transgenic Mice on Cholesterol Efflux From J774 Macrophages and Fu5AH Hepatoma Cells","authors":"N. Fournier, A. Cogny, V. Atger, D. Pastier, D. Goudounèche, A. Nicoletti, N. Moatti, J. Chambaz, J. Paul, A. Kalopissis","doi":"10.1161/01.ATV.0000013023.11297.B2","DOIUrl":"https://doi.org/10.1161/01.ATV.0000013023.11297.B2","url":null,"abstract":"Overexpression of human apolipoprotein A-II (hapo A-II) in transgenic mice (hAIItg mice) induced marked hypertriglyceridemia and low levels of plasma high density lipoprotein (HDL) with a high hapo A-II content. We sought to determine whether cholesterol efflux to plasma and HDL from these mice would be affected. In the Fu5AH cell system, plasma from hAIItg mice induced a markedly lower cholesterol efflux than did control plasma, in accordance with the dependence of efflux on HDL concentration. Moreover, HDLs from hAIItg mice were less effective acceptors than were control HDLs. In the J774 macrophage cell system, pretreatment with cAMP, which upregulates ATP binding cassette transporter 1, induced a marked increase in the efflux to hAIItg plasma as well as to purified hapo A-I and hapo A-II, whereas it had no effect on cholesterol efflux to control plasma. A strong positive correlation was established between percent cAMP stimulation of efflux and plasma hapo A-II concentration. The cAMP stimulation of efflux to hAIItg mouse plasma may be linked to the presence of pre-&bgr; migrating HDL containing hapo A-II. Thus, despite lower HDL and apolipoprotein A-I contents, the increased ability of plasma from hAIItg mice to extract cholesterol from macrophage-like cells may have an antiatherogenic influence.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91426616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000013778.72404.30
F. Miller, W. Sharp, Xiang Fang, L. Oberley, T. Oberley, N. Weintraub
Abdominal aortic aneurysm (AAA) is an inflammatory disorder characterized by localized connective tissue degradation and smooth muscle cell (SMC) apoptosis, leading to aortic dilatation and rupture. Reactive oxygen species are abundantly produced during inflammatory processes and can stimulate connective tissue–degrading proteases and apoptosis of SMCs. We hypothesized that reactive oxygen species are locally increased in AAA and lead to enhanced oxidative stress. In aortas from patients undergoing surgical repair, superoxide levels (measured by lucigenin-enhanced chemiluminescence) were 2.5-fold higher in the AAA segments compared with the adjacent nonaneurysmal aortic (NA) segments (6638±2164 versus 2675±1027 relative light units for 5 minutes per millimeter squared, respectively; n=7). Formation of thiobarbituric acid–reactive substances and conjugated dienes, 2 indices of lipid peroxidation, were increased 3-fold in AAA compared with NA segments. Immunostaining for nitrotyrosine was significantly greater in AAA tissue. Dihydroethidium staining indicated that increased superoxide in AAA segments was localized to infiltrating inflammatory cells and to SMCs. Expression of the NADPH oxidase subunits p47phox and p22phox and NAD(P)H oxidase activity were increased in AAA segments compared with NA segments. Thus, oxidative stress is markedly increased in AAA, in part through the activation of NAD(P)H oxidase, and may contribute to the disease pathogenesis.
{"title":"Oxidative Stress in Human Abdominal Aortic Aneurysms: A Potential Mediator of Aneurysmal Remodeling","authors":"F. Miller, W. Sharp, Xiang Fang, L. Oberley, T. Oberley, N. Weintraub","doi":"10.1161/01.ATV.0000013778.72404.30","DOIUrl":"https://doi.org/10.1161/01.ATV.0000013778.72404.30","url":null,"abstract":"Abdominal aortic aneurysm (AAA) is an inflammatory disorder characterized by localized connective tissue degradation and smooth muscle cell (SMC) apoptosis, leading to aortic dilatation and rupture. Reactive oxygen species are abundantly produced during inflammatory processes and can stimulate connective tissue–degrading proteases and apoptosis of SMCs. We hypothesized that reactive oxygen species are locally increased in AAA and lead to enhanced oxidative stress. In aortas from patients undergoing surgical repair, superoxide levels (measured by lucigenin-enhanced chemiluminescence) were 2.5-fold higher in the AAA segments compared with the adjacent nonaneurysmal aortic (NA) segments (6638±2164 versus 2675±1027 relative light units for 5 minutes per millimeter squared, respectively; n=7). Formation of thiobarbituric acid–reactive substances and conjugated dienes, 2 indices of lipid peroxidation, were increased 3-fold in AAA compared with NA segments. Immunostaining for nitrotyrosine was significantly greater in AAA tissue. Dihydroethidium staining indicated that increased superoxide in AAA segments was localized to infiltrating inflammatory cells and to SMCs. Expression of the NADPH oxidase subunits p47phox and p22phox and NAD(P)H oxidase activity were increased in AAA segments compared with NA segments. Thus, oxidative stress is markedly increased in AAA, in part through the activation of NAD(P)H oxidase, and may contribute to the disease pathogenesis.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85121001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000012782.59850.41
J. Huber, H. Boechzelt, B. Karten, Michael Surboeck, V. Bochkov, B. Binder, W. Sattler, N. Leitinger
Oxidation products of cholesteryl esters have been shown to be present in oxidized low density lipoprotein and in atherosclerotic lesions. Monocyte adhesion to the endothelium is an initiating crucial event in atherogenesis. Here, we show that in vitro oxidized cholesteryl linoleate (oxCL) stimulated human umbilical vein endothelial cells (HUVECs) to bind human peripheral blood mononuclear cells as well as monocyte-like U937 cells but not peripheral blood neutrophils or neutrophil-like HL-60 cells. Among the oxidation products contained in oxCLs, 9-oxononanoyl cholesterol (9-ONC) and cholesteryl linoleate hydroperoxides stimulated U937 cell adhesion. OxCL-induced U937 cell adhesion was inhibited by an antibody against the connecting segment-1 region of fibronectin. Neither oxCL nor 9-ONC induced activation of the classical nuclear factor-&kgr;B pathway. In contrast, stimulation of HUVECs with oxCL resulted in phosphorylation of the extracellular signal–regulated kinase 1/2. Moreover, U937 cell adhesion induced by 9-ONC and oxCL was blocked by a mitogen-activated protein kinase/extracellular signal–regulated kinase inhibitor and a protein kinase C inhibitor. Taken together, oxCLs stimulate HUVECs to specifically bind monocytes, involving endothelial connecting segment-1 and the activation of a protein kinase C– and mitogen-activated protein kinase–dependent pathway. Thus, oxidized cholesteryl esters may play an important role as novel mediators in the initiation and progression of atherosclerosis.
{"title":"Oxidized Cholesteryl Linoleates Stimulate Endothelial Cells to Bind Monocytes via the Extracellular Signal–Regulated Kinase 1/2 Pathway","authors":"J. Huber, H. Boechzelt, B. Karten, Michael Surboeck, V. Bochkov, B. Binder, W. Sattler, N. Leitinger","doi":"10.1161/01.ATV.0000012782.59850.41","DOIUrl":"https://doi.org/10.1161/01.ATV.0000012782.59850.41","url":null,"abstract":"Oxidation products of cholesteryl esters have been shown to be present in oxidized low density lipoprotein and in atherosclerotic lesions. Monocyte adhesion to the endothelium is an initiating crucial event in atherogenesis. Here, we show that in vitro oxidized cholesteryl linoleate (oxCL) stimulated human umbilical vein endothelial cells (HUVECs) to bind human peripheral blood mononuclear cells as well as monocyte-like U937 cells but not peripheral blood neutrophils or neutrophil-like HL-60 cells. Among the oxidation products contained in oxCLs, 9-oxononanoyl cholesterol (9-ONC) and cholesteryl linoleate hydroperoxides stimulated U937 cell adhesion. OxCL-induced U937 cell adhesion was inhibited by an antibody against the connecting segment-1 region of fibronectin. Neither oxCL nor 9-ONC induced activation of the classical nuclear factor-&kgr;B pathway. In contrast, stimulation of HUVECs with oxCL resulted in phosphorylation of the extracellular signal–regulated kinase 1/2. Moreover, U937 cell adhesion induced by 9-ONC and oxCL was blocked by a mitogen-activated protein kinase/extracellular signal–regulated kinase inhibitor and a protein kinase C inhibitor. Taken together, oxCLs stimulate HUVECs to specifically bind monocytes, involving endothelial connecting segment-1 and the activation of a protein kinase C– and mitogen-activated protein kinase–dependent pathway. Thus, oxidized cholesteryl esters may play an important role as novel mediators in the initiation and progression of atherosclerosis.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88540088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000012805.49079.23
J. Remijn, Ya-Ping Wu, E. Jeninga, M. Ijsseldijk, G. van Willigen, P. D. de Groot, J. Sixma, A. Nurden, P. Nurden
ADP plays a central role in regulating platelet function. It induces platelet aggregation via the activation of 2 major ADP receptors, P2Y1 and P2Y12. We have investigated the role of P2Y12 in platelet adhesion and thrombus formation under physiological flow by using blood from a patient with a defect in the gene encoding P2Y12. Anticoagulated blood from the patient and from healthy volunteers was perfused over collagen-coated coverslips. The patient’s thrombi were smaller and consisted of spread platelets overlying platelets that were not spread, whereas control thrombi were large and densely packed. Identical platelet surface coverage, aggregate size, and morphology were found when a P2Y12 antagonist, N6-(2-methylthioethyl)-2-(3,3,3-trifluoropropylthio)-&bgr;,&ggr;-dichloromethylene ATP (also known as AR-C69931 MX), was added to control blood. The addition of a P2Y1 antagonist (adenosine-3′,5′-diphospate) to control blood resulted in small, but normally structured, thrombi. Thus, the ADP-P2Y12 interaction is essential for normal thrombus buildup on collagen. The patient’s blood also showed reduced platelet adhesion on fibrinogen, which was not due to changes in morphology. Comparable results were found by using control blood with AR-C69931 MX and also with adenosine-3′,5′-diphospate. This suggested that P2Y12 and P2Y1 were both involved in platelet adhesion on immobilized fibrinogen, thereby revealing it as ADP dependent. This was confirmed by complete inhibition on the addition of creatine phosphate/creatine phosphokinase.
{"title":"Role of ADP Receptor P2Y12 in Platelet Adhesion and Thrombus Formation in Flowing Blood","authors":"J. Remijn, Ya-Ping Wu, E. Jeninga, M. Ijsseldijk, G. van Willigen, P. D. de Groot, J. Sixma, A. Nurden, P. Nurden","doi":"10.1161/01.ATV.0000012805.49079.23","DOIUrl":"https://doi.org/10.1161/01.ATV.0000012805.49079.23","url":null,"abstract":"ADP plays a central role in regulating platelet function. It induces platelet aggregation via the activation of 2 major ADP receptors, P2Y1 and P2Y12. We have investigated the role of P2Y12 in platelet adhesion and thrombus formation under physiological flow by using blood from a patient with a defect in the gene encoding P2Y12. Anticoagulated blood from the patient and from healthy volunteers was perfused over collagen-coated coverslips. The patient’s thrombi were smaller and consisted of spread platelets overlying platelets that were not spread, whereas control thrombi were large and densely packed. Identical platelet surface coverage, aggregate size, and morphology were found when a P2Y12 antagonist, N6-(2-methylthioethyl)-2-(3,3,3-trifluoropropylthio)-&bgr;,&ggr;-dichloromethylene ATP (also known as AR-C69931 MX), was added to control blood. The addition of a P2Y1 antagonist (adenosine-3′,5′-diphospate) to control blood resulted in small, but normally structured, thrombi. Thus, the ADP-P2Y12 interaction is essential for normal thrombus buildup on collagen. The patient’s blood also showed reduced platelet adhesion on fibrinogen, which was not due to changes in morphology. Comparable results were found by using control blood with AR-C69931 MX and also with adenosine-3′,5′-diphospate. This suggested that P2Y12 and P2Y1 were both involved in platelet adhesion on immobilized fibrinogen, thereby revealing it as ADP dependent. This was confirmed by complete inhibition on the addition of creatine phosphate/creatine phosphokinase.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83291896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000014804.35824.DA
R. Aiello, D. Brees, P. Bourassa, L. Royer, S. Lindsey, Timothy M. Coskran, M. Haghpassand, O. Francone
The ATP-binding cassette transporter A1 (ABCA1) encodes a membrane protein that promotes cholesterol and phospholipid efflux from cells. Mutations in ABCA1 lead to HDL deficiency and tissue accumulation of macrophages in patients with homozygous Tangier disease. In this study, we examined whether the complete absence of ABCA1 or selected inactivation in macrophages is accompanied by an increase in atherosclerotic lesion progression in hypercholesterolemic apolipoprotein E–deficient (apoE−/−) mice and LDLR receptor–deficient (LDLr−/−) mice. The absence of ABCA1 led to reduced plasma cholesterol levels in both the apoE−/− and LDLr−/− mice, along with severe skin xanthomatosis characterized by marked foamy macrophages and cholesterol ester accumulation. However, the complete absence of ABCA1 did not affect the development, progression, or composition of atherosclerotic lesions in either the LDLr−/− or the apoE−/− mice fed a chow or atherogenic diet. In contrast, bone marrow transplantation studies demonstrated that the selective inactivation of ABCA1 in macrophages markedly increased atherosclerosis and foam cell accumulation in apoE−/−. Taken together, these findings demonstrate that the complete absence of ABCA1 has a major impact on plasma lipoprotein homeostasis, and the proposed antiatherogenic effect resulting from ABCA1 deficiency is compensated by a less atherogenic profile. ABCA1 deficiency in macrophages, however, demonstrates the antiatherogenic properties of ABCA1 independent of plasma lipids and HDL levels.
{"title":"Increased Atherosclerosis in Hyperlipidemic Mice With Inactivation of ABCA1 in Macrophages","authors":"R. Aiello, D. Brees, P. Bourassa, L. Royer, S. Lindsey, Timothy M. Coskran, M. Haghpassand, O. Francone","doi":"10.1161/01.ATV.0000014804.35824.DA","DOIUrl":"https://doi.org/10.1161/01.ATV.0000014804.35824.DA","url":null,"abstract":"The ATP-binding cassette transporter A1 (ABCA1) encodes a membrane protein that promotes cholesterol and phospholipid efflux from cells. Mutations in ABCA1 lead to HDL deficiency and tissue accumulation of macrophages in patients with homozygous Tangier disease. In this study, we examined whether the complete absence of ABCA1 or selected inactivation in macrophages is accompanied by an increase in atherosclerotic lesion progression in hypercholesterolemic apolipoprotein E–deficient (apoE−/−) mice and LDLR receptor–deficient (LDLr−/−) mice. The absence of ABCA1 led to reduced plasma cholesterol levels in both the apoE−/− and LDLr−/− mice, along with severe skin xanthomatosis characterized by marked foamy macrophages and cholesterol ester accumulation. However, the complete absence of ABCA1 did not affect the development, progression, or composition of atherosclerotic lesions in either the LDLr−/− or the apoE−/− mice fed a chow or atherogenic diet. In contrast, bone marrow transplantation studies demonstrated that the selective inactivation of ABCA1 in macrophages markedly increased atherosclerosis and foam cell accumulation in apoE−/−. Taken together, these findings demonstrate that the complete absence of ABCA1 has a major impact on plasma lipoprotein homeostasis, and the proposed antiatherogenic effect resulting from ABCA1 deficiency is compensated by a less atherogenic profile. ABCA1 deficiency in macrophages, however, demonstrates the antiatherogenic properties of ABCA1 independent of plasma lipids and HDL levels.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86471927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000012455.62765.BF
P. Dimayuga, B. Cercek, S. Oguchi, G. N. Fredrikson, J. Yano, P. Shah, S. Jovinge, J. Nilsson
We investigated the effect of B-cell reconstitution in immune-deficient Rag-1 knockout (KO) mice subjected to arterial injury. After 21 days, injury induced a 4- to 5-fold increase in neointimal formation in Rag-1 KO mice fed normal chow compared with wild-type (WT) mice (0.020±0.0160 [n=8] versus 0.0049±0.0022 [n=8] mm2, respectively;P <0.05) and in western-type diet–fed Rag-1 KO mice compared with WT mice (0.0312±0.0174 [n=7] versus 0.0050±0.0028 [n=6] mm2, respectively;P <0.05). To investigate the role of B cells in response to injury, Rag-1 KO mice were reconstituted with B cells derived from the spleens of WT mice, with donors and recipients on the same diet. Reconstitution of Rag-1 KO mice with B cells from WT mice (both fed normal chow) reduced neointimal formation compared with the effect in unreconstituted Rag-1 KO mice (0.0076±0.0039 [n=9] versus 0.020±0.0160 [n=8] mm2, respectively;P <0.05). Reconstitution of Rag-1 KO mice with B cells from WT mice (both fed a western diet) reduced neointimal formation compared the effect in Rag-1 KO mice (0.0087±0.0037 [n=8] versus 0.0312±0.0174 [n=7] mm2, respectively;P <0.05). Injured carotid arteries from reconstituted Rag-1 KO mice had detectable IgM and IgG, indicating viable transfer of B cells. The results suggest that B cells modulate the response to arterial injury.
我们研究了免疫缺陷rag1敲除(KO)小鼠动脉损伤后b细胞重构的影响。21 d后，正常饲料喂养的Rag-1 KO小鼠的新生内膜形成比野生型(WT)小鼠增加4 ~ 5倍(分别为0.020±0.0160 [n=8]和0.0049±0.0022 [n=8] mm2, P <0.05)，西式饲料喂养的Rag-1 KO小鼠的新生内膜形成比野生型(WT)小鼠增加4 ~ 5倍(分别为0.0312±0.0174 [n=7]和0.0050±0.0028 [n=6] mm2, P <0.05)。为了研究B细胞在损伤反应中的作用，我们用来自WT小鼠脾脏的B细胞重建了rag1 KO小鼠，供体和受体的饮食相同。与未重组的rag1 - KO小鼠相比，用WT小鼠的B细胞重组rag1 - KO小鼠(均饲喂正常食物)减少了新内膜的形成(分别为0.0076±0.0039 [n=9]和0.020±0.0160 [n=8] mm2, P <0.05)。用WT小鼠的B细胞重建Rag-1 KO小鼠(均饲喂西方饮食)，与Rag-1 KO小鼠相比，新内膜形成减少(分别为0.0087±0.0037 [n=8]和0.0312±0.0174 [n=7] mm2, P <0.05)。重组Rag-1 KO小鼠损伤颈动脉中检测到IgM和IgG，表明B细胞有活力转移。结果提示B细胞可调节动脉损伤反应。
{"title":"Inhibitory Effect on Arterial Injury-Induced Neointimal Formation by Adoptive B-Cell Transfer in Rag-1 Knockout Mice","authors":"P. Dimayuga, B. Cercek, S. Oguchi, G. N. Fredrikson, J. Yano, P. Shah, S. Jovinge, J. Nilsson","doi":"10.1161/01.ATV.0000012455.62765.BF","DOIUrl":"https://doi.org/10.1161/01.ATV.0000012455.62765.BF","url":null,"abstract":"We investigated the effect of B-cell reconstitution in immune-deficient Rag-1 knockout (KO) mice subjected to arterial injury. After 21 days, injury induced a 4- to 5-fold increase in neointimal formation in Rag-1 KO mice fed normal chow compared with wild-type (WT) mice (0.020±0.0160 [n=8] versus 0.0049±0.0022 [n=8] mm2, respectively;P <0.05) and in western-type diet–fed Rag-1 KO mice compared with WT mice (0.0312±0.0174 [n=7] versus 0.0050±0.0028 [n=6] mm2, respectively;P <0.05). To investigate the role of B cells in response to injury, Rag-1 KO mice were reconstituted with B cells derived from the spleens of WT mice, with donors and recipients on the same diet. Reconstitution of Rag-1 KO mice with B cells from WT mice (both fed normal chow) reduced neointimal formation compared with the effect in unreconstituted Rag-1 KO mice (0.0076±0.0039 [n=9] versus 0.020±0.0160 [n=8] mm2, respectively;P <0.05). Reconstitution of Rag-1 KO mice with B cells from WT mice (both fed a western diet) reduced neointimal formation compared the effect in Rag-1 KO mice (0.0087±0.0037 [n=8] versus 0.0312±0.0174 [n=7] mm2, respectively;P <0.05). Injured carotid arteries from reconstituted Rag-1 KO mice had detectable IgM and IgG, indicating viable transfer of B cells. The results suggest that B cells modulate the response to arterial injury.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85567826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000013287.08141.74
M. Broeders, G. Tangelder, D. Slaaf, R. Reneman, M. O. oude Egbrink
We investigated in vivo the effect of cholesterol diet–induced hypercholesterolemia (HC) on thromboembolism in nonatherosclerotic rabbit mesenteric arterioles and venules (diameter 21 to 45 &mgr;m). After mechanical vessel wall injury, the ensuing thromboembolic reaction was studied by intravital videomicroscopy. A dramatic prolongation of embolization duration (median >600 seconds) was observed in the arterioles of the HC group compared with the arterioles of a normal chow–fed (NC) control group (142 seconds, P <0.0001); concomitantly, relative thrombus height increased (thrombus height/vessel diameter was 68% for the HC group and 58% for the NC group;P <0.05). By contrast, in venules, cholesterol did not affect embolization duration (42 seconds for HC group, 34 seconds for NC group) and thrombus height (66% for HC group, 64% for NC group). Furthermore, the role of endothelial NO synthesis was studied. In arterioles, stimulation of endogenous NO synthesis through mesenteric superfusion of l-arginine (1 mmol/L) completely reversed cholesterol-enhanced embolization (152 seconds) but did not influence thrombus height (63%). l-Arginine had no effect in venules of the HC group (51 seconds) and nor in the arterioles and venules of the NC group (177 seconds for arterioles, 43 seconds for venules). This study indicates that hypercholesterolemia selectively enhances thrombus formation and embolization in arterioles but not in venules and that stimulation of endogenous NO production antagonizes this enhancement of arteriolar thromboembolism.
{"title":"Hypercholesterolemia Enhances Thromboembolism in Arterioles but Not Venules: Complete Reversal by l-Arginine","authors":"M. Broeders, G. Tangelder, D. Slaaf, R. Reneman, M. O. oude Egbrink","doi":"10.1161/01.ATV.0000013287.08141.74","DOIUrl":"https://doi.org/10.1161/01.ATV.0000013287.08141.74","url":null,"abstract":"We investigated in vivo the effect of cholesterol diet–induced hypercholesterolemia (HC) on thromboembolism in nonatherosclerotic rabbit mesenteric arterioles and venules (diameter 21 to 45 &mgr;m). After mechanical vessel wall injury, the ensuing thromboembolic reaction was studied by intravital videomicroscopy. A dramatic prolongation of embolization duration (median >600 seconds) was observed in the arterioles of the HC group compared with the arterioles of a normal chow–fed (NC) control group (142 seconds, P <0.0001); concomitantly, relative thrombus height increased (thrombus height/vessel diameter was 68% for the HC group and 58% for the NC group;P <0.05). By contrast, in venules, cholesterol did not affect embolization duration (42 seconds for HC group, 34 seconds for NC group) and thrombus height (66% for HC group, 64% for NC group). Furthermore, the role of endothelial NO synthesis was studied. In arterioles, stimulation of endogenous NO synthesis through mesenteric superfusion of l-arginine (1 mmol/L) completely reversed cholesterol-enhanced embolization (152 seconds) but did not influence thrombus height (63%). l-Arginine had no effect in venules of the HC group (51 seconds) and nor in the arterioles and venules of the NC group (177 seconds for arterioles, 43 seconds for venules). This study indicates that hypercholesterolemia selectively enhances thrombus formation and embolization in arterioles but not in venules and that stimulation of endogenous NO production antagonizes this enhancement of arteriolar thromboembolism.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89424153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-04-01DOI: 10.1161/01.ATV.0000013785.03265.5C
A. Jenner, J. Ruiz, C. Dunster, B. Halliwell, G. Mann, R. Siow
Hypochlorous acid (HOCl), generated by myeloperoxidase released from activated macrophages, is thought to contribute to vascular dysfunction and oxidation of low density lipoproteins (LDLs) in atherogenesis. We have previously shown that HOCl exposure can cause chlorination and oxidation of isolated DNA and that vitamin C protects human arterial smooth muscle cells against oxidized LDL–mediated damage. We report in the present study that vitamin C attenuates HOCl-induced DNA base and protein damage and depletion of intracellular glutathione (GSH) and ATP in human arterial smooth muscle cells. Cells were pretreated in the absence or presence of 100 &mgr;mol/L vitamin C (24 hours) and then exposed to HOCl (0 to 500 &mgr;mol/L, 0 to 60 minutes) in the absence of vitamin C. Intracellular GSH and ATP levels were depleted by HOCl treatment, and gas chromatography–mass spectroscopy revealed a concentration- and time-dependent increase in DNA base oxidation and protein damage (measured as 3-chlorotyrosine). Pretreatment of smooth muscle cells with vitamin C significantly reduced the extent of HOCl-induced DNA and protein damage and attenuated decreases in intracellular ATP and GSH. Our findings suggest that physiological levels of vitamin C provide an important antioxidant defense against HOCl-mediated injury in atherosclerosis.
{"title":"Vitamin C Protects Against Hypochlorous Acid–Induced Glutathione Depletion and DNA Base and Protein Damage in Human Vascular Smooth Muscle Cells","authors":"A. Jenner, J. Ruiz, C. Dunster, B. Halliwell, G. Mann, R. Siow","doi":"10.1161/01.ATV.0000013785.03265.5C","DOIUrl":"https://doi.org/10.1161/01.ATV.0000013785.03265.5C","url":null,"abstract":"Hypochlorous acid (HOCl), generated by myeloperoxidase released from activated macrophages, is thought to contribute to vascular dysfunction and oxidation of low density lipoproteins (LDLs) in atherogenesis. We have previously shown that HOCl exposure can cause chlorination and oxidation of isolated DNA and that vitamin C protects human arterial smooth muscle cells against oxidized LDL–mediated damage. We report in the present study that vitamin C attenuates HOCl-induced DNA base and protein damage and depletion of intracellular glutathione (GSH) and ATP in human arterial smooth muscle cells. Cells were pretreated in the absence or presence of 100 &mgr;mol/L vitamin C (24 hours) and then exposed to HOCl (0 to 500 &mgr;mol/L, 0 to 60 minutes) in the absence of vitamin C. Intracellular GSH and ATP levels were depleted by HOCl treatment, and gas chromatography–mass spectroscopy revealed a concentration- and time-dependent increase in DNA base oxidation and protein damage (measured as 3-chlorotyrosine). Pretreatment of smooth muscle cells with vitamin C significantly reduced the extent of HOCl-induced DNA and protein damage and attenuated decreases in intracellular ATP and GSH. Our findings suggest that physiological levels of vitamin C provide an important antioxidant defense against HOCl-mediated injury in atherosclerosis.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74950716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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