Pub Date : 2002-08-01DOI: 10.1161/01.ATV.0000026297.50542.62
Cheng-ai Wu, M. Tsujita, K. Okumura‐Noji, S. Usui, Hajime Kakuuchi, M. Okazaki, S. Yokoyama
Objective—Regulation of plasma cholesteryl ester transfer protein (CETP) concentration was studied in lecithin-cholesterol acyltransferase (LCAT)-knockout mice. Methods and Results—LCAT-knockout mice were cross-bred with CETP transgenic mice. The offspring (n=63) were classified for LCAT genotype and plasma CETP levels (no CETP, low CETP, and high CETP). High density lipoprotein (HDL) decreased as LCAT decreased in each CETP-level group. In the lcat(+/+) and lcat(+/ −) mice, plasma CETP varied from 0 to 30 &mgr;g/mL, whereas it was <10 &mgr;g/mL in the lcat( −/ −) mice. HDL cholesterol and phospholipid decreased and HDL triglyceride and apolipoprotein B increased in CETP in the lcat(+/+) and lcat(+/ −) mice, whereas there was no difference in HDL between low and high CETP. An effect of CETP on HDL was not detected in the lcat( −/ −) mice because of the absence of mature HDL. Genomic DNA and mRNA of CETP were correlated and were similar in the lcat( −/ −) and lcat(+/+) mice. Plasma CETP was correlated with its genomic DNA and mRNA, but the slope of the increase was much lower in the lcat( −/ −) mice. Whereas plasma CETP mostly associates with HDL in the lcat(+/+) mouse, it is found free in the lcat( −/ −) mouse. Conclusions—Plasma CETP is posttranscriptionally downregulated in the lcat( −/ −) mice, presumably by its extremely low HDL.
{"title":"Cholesteryl Ester Transfer Protein Expressed in Lecithin Cholesterol Acyltransferase–Deficient Mice","authors":"Cheng-ai Wu, M. Tsujita, K. Okumura‐Noji, S. Usui, Hajime Kakuuchi, M. Okazaki, S. Yokoyama","doi":"10.1161/01.ATV.0000026297.50542.62","DOIUrl":"https://doi.org/10.1161/01.ATV.0000026297.50542.62","url":null,"abstract":"Objective—Regulation of plasma cholesteryl ester transfer protein (CETP) concentration was studied in lecithin-cholesterol acyltransferase (LCAT)-knockout mice. Methods and Results—LCAT-knockout mice were cross-bred with CETP transgenic mice. The offspring (n=63) were classified for LCAT genotype and plasma CETP levels (no CETP, low CETP, and high CETP). High density lipoprotein (HDL) decreased as LCAT decreased in each CETP-level group. In the lcat(+/+) and lcat(+/ −) mice, plasma CETP varied from 0 to 30 &mgr;g/mL, whereas it was <10 &mgr;g/mL in the lcat( −/ −) mice. HDL cholesterol and phospholipid decreased and HDL triglyceride and apolipoprotein B increased in CETP in the lcat(+/+) and lcat(+/ −) mice, whereas there was no difference in HDL between low and high CETP. An effect of CETP on HDL was not detected in the lcat( −/ −) mice because of the absence of mature HDL. Genomic DNA and mRNA of CETP were correlated and were similar in the lcat( −/ −) and lcat(+/+) mice. Plasma CETP was correlated with its genomic DNA and mRNA, but the slope of the increase was much lower in the lcat( −/ −) mice. Whereas plasma CETP mostly associates with HDL in the lcat(+/+) mouse, it is found free in the lcat( −/ −) mouse. Conclusions—Plasma CETP is posttranscriptionally downregulated in the lcat( −/ −) mice, presumably by its extremely low HDL.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81657123","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 : 2002-08-01DOI: 10.1161/01.ATV.0000024222.06463.21
M. Järvisalo, A. Harmoinen, Maarit Hakanen, U. Paakkunainen, J. Viikari, J. Hartiala, T. Lehtimäki, O. Simell, O. Raitakari
Objective—Elevated serum concentration of C-reactive protein (CRP) predicts cardiovascular events in adults. Because atherosclerosis begins in childhood, we undertook a study to determine whether changes in brachial artery endothelial function and the thickness of the carotid intima-media complex, 2 markers of early atherosclerosis, are related to CRP levels in healthy children. Methods and Results—Brachial artery flow-mediated dilatation (FMD) and carotid artery intima-media thickness (IMT) were measured with ultrasound in 79 children (aged 10.5±1.1 years). Compared with the children with CRP levels under the detection limit (<0.1 mg/L, n=40, group 1), the children with higher CRP (0.1 mg/L≤CRP≤0.7 mg/L, n=20, group 2; CRP >0.7 mg/L, n=19, group 3) had lower FMD (9.0±4.4% versus 7.8±3.3% versus 6.5±2.6%, respectively;P =0.015 for trend) and greater carotid IMT (0.45±0.03 versus 0.46±0.04 versus 0.49±0.06 mm, respectively, P =0.002 for trend). CRP level remained a statistically significant independent predictor for brachial FMD and carotid IMT in multivariate analyses. Conclusions—These data suggest that CRP affects the arteries of healthy children by disturbing endothelial function and promoting intima-media thickening. The findings support the hypothesis that CRP plays a role in the pathogenesis of early atherosclerosis.
目的:血清c反应蛋白(CRP)浓度升高可预测成人心血管事件。由于动脉粥样硬化始于儿童时期，我们进行了一项研究，以确定健康儿童的臂动脉内皮功能和颈动脉内膜-中膜复合体厚度的变化(早期动脉粥样硬化的两个标志)是否与CRP水平有关。方法与结果:对79例儿童(年龄10.5±1.1岁)的肱动脉血流介导扩张(FMD)和颈动脉内膜-中膜厚度(IMT)进行超声测量。与CRP水平低于检出限(0.7 mg/L, n=19，组3)的儿童相比，FMD较低(分别为9.0±4.4%对7.8±3.3%对6.5±2.6%，P =0.015趋势)，颈动脉IMT较大(分别为0.45±0.03对0.46±0.04对0.49±0.06 mm, P =0.002趋势)。在多变量分析中，CRP水平仍然是具有统计学意义的肱FMD和颈动脉IMT的独立预测因子。结论:这些数据表明CRP通过干扰内皮功能和促进内膜-中膜增厚来影响健康儿童的动脉。这些发现支持了CRP在早期动脉粥样硬化发病机制中起作用的假设。
{"title":"Elevated Serum C-Reactive Protein Levels and Early Arterial Changes in Healthy Children","authors":"M. Järvisalo, A. Harmoinen, Maarit Hakanen, U. Paakkunainen, J. Viikari, J. Hartiala, T. Lehtimäki, O. Simell, O. Raitakari","doi":"10.1161/01.ATV.0000024222.06463.21","DOIUrl":"https://doi.org/10.1161/01.ATV.0000024222.06463.21","url":null,"abstract":"Objective—Elevated serum concentration of C-reactive protein (CRP) predicts cardiovascular events in adults. Because atherosclerosis begins in childhood, we undertook a study to determine whether changes in brachial artery endothelial function and the thickness of the carotid intima-media complex, 2 markers of early atherosclerosis, are related to CRP levels in healthy children. Methods and Results—Brachial artery flow-mediated dilatation (FMD) and carotid artery intima-media thickness (IMT) were measured with ultrasound in 79 children (aged 10.5±1.1 years). Compared with the children with CRP levels under the detection limit (<0.1 mg/L, n=40, group 1), the children with higher CRP (0.1 mg/L≤CRP≤0.7 mg/L, n=20, group 2; CRP >0.7 mg/L, n=19, group 3) had lower FMD (9.0±4.4% versus 7.8±3.3% versus 6.5±2.6%, respectively;P =0.015 for trend) and greater carotid IMT (0.45±0.03 versus 0.46±0.04 versus 0.49±0.06 mm, respectively, P =0.002 for trend). CRP level remained a statistically significant independent predictor for brachial FMD and carotid IMT in multivariate analyses. Conclusions—These data suggest that CRP affects the arteries of healthy children by disturbing endothelial function and promoting intima-media thickening. The findings support the hypothesis that CRP plays a role in the pathogenesis of early atherosclerosis.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84749199","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 : 2002-08-01DOI: 10.1161/01.ATV.0000027101.40323.3A
G. Jarvik, N. Tsai, Laura A. McKinstry, R. Wani, V. Brophy, R. Richter, G. Schellenberg, P. Heagerty, T. Hatsukami, C. Furlong
Objective—Paraoxonase (PON1), an esterase physically associated with high density lipoprotein, has been shown to inhibit atherogenic low density lipoprotein and high density lipoprotein oxidation. PON1 activity appears to be primarily under genetic control with some environmental modification and is a predictor of vascular disease. Vitamins C and E, dietary antioxidants, scavenge free-oxygen radical products that may depress PON1 activity. Therefore, we evaluated the relationship between dietary vitamin C and E intake and PON1 activity. Methods and Results—The vitamin C and E intakes of male white subjects (n=189) were estimated by using a standardized food frequency survey. With covariates, vitamin C or E intakes were found to be significant positive predictors of PON1 activity for the hydrolysis of paraoxon and diazoxon with the use of linear regression. Smoking and use of statins were independent predictors of PON1 activity. Conclusions—PON1 activity, which is primarily genotype dependent, varies with antioxidant vitamins, cigarette smoking, and statin drug use. Because PON1 activity is a better predictor of vascular disease than is the currently described genetic variation in PON1, further studies of the environmental influences on PON1 activity and additional PON1 genetic variants are warranted.
{"title":"Vitamin C and E Intake Is Associated With Increased Paraoxonase Activity","authors":"G. Jarvik, N. Tsai, Laura A. McKinstry, R. Wani, V. Brophy, R. Richter, G. Schellenberg, P. Heagerty, T. Hatsukami, C. Furlong","doi":"10.1161/01.ATV.0000027101.40323.3A","DOIUrl":"https://doi.org/10.1161/01.ATV.0000027101.40323.3A","url":null,"abstract":"Objective—Paraoxonase (PON1), an esterase physically associated with high density lipoprotein, has been shown to inhibit atherogenic low density lipoprotein and high density lipoprotein oxidation. PON1 activity appears to be primarily under genetic control with some environmental modification and is a predictor of vascular disease. Vitamins C and E, dietary antioxidants, scavenge free-oxygen radical products that may depress PON1 activity. Therefore, we evaluated the relationship between dietary vitamin C and E intake and PON1 activity. Methods and Results—The vitamin C and E intakes of male white subjects (n=189) were estimated by using a standardized food frequency survey. With covariates, vitamin C or E intakes were found to be significant positive predictors of PON1 activity for the hydrolysis of paraoxon and diazoxon with the use of linear regression. Smoking and use of statins were independent predictors of PON1 activity. Conclusions—PON1 activity, which is primarily genotype dependent, varies with antioxidant vitamins, cigarette smoking, and statin drug use. Because PON1 activity is a better predictor of vascular disease than is the currently described genetic variation in PON1, further studies of the environmental influences on PON1 activity and additional PON1 genetic variants are warranted.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87798089","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 : 2002-08-01DOI: 10.1161/01.ATV.0000024684.67566.45
T. Ichii, H. Koyama, Shinji Tanaka, A. Shioi, Y. Okuno, S. Otani, Y. Nishizawà
Objectives—Platelet adherence and activation are associated with smooth muscle cell (SMC) proliferation and arterial restenosis. This study examined platelet-SMC interaction on fibrillar type I collagen and analyzed the role of thrombospondin (TSP)-1 in platelet-induced SMC proliferation. Methods and Results—When SMCs cultured on fibrillar collagen were treated with human platelets (5 preparations), 7.45±2.94% of the cells passed through S phase within 24 hours, as determined by bromodeoxyuridine nuclear labeling. The addition of platelets markedly induced SMC TSP-1 mRNA expression and cell surface protein accumulation, which colocalized with adhered platelets, as determined by &agr;IIb integrin immunostaining. Direct interaction of platelets with SMCs was necessary for its effect on proliferation and TSP-1 accumulation, as determined in the transwell culture system. The anti–TSP-1 blocking antibody strongly inhibited platelet-induced SMC proliferation by ≈60%. Analysis of the receptors for TSP-1 accumulation on the SMC surface revealed that &bgr;1 integrins are mainly involved. The anti–&bgr;1 integrin blocking antibody, which potently suppressed TSP-1 accumulation on SMCs, also markedly inhibited platelet-stimulated SMC proliferation. Conclusions—TSP-1 and &bgr;1 integrin interaction is involved in platelet-stimulated SMC proliferation. This in vitro coculture system could prove useful for examining the molecular mechanism underlying platelet-induced vascular remodeling and for studying the mechanism of a tested drug for restenosis.
{"title":"Thrombospondin-1 Mediates Smooth Muscle Cell Proliferation Induced by Interaction With Human Platelets","authors":"T. Ichii, H. Koyama, Shinji Tanaka, A. Shioi, Y. Okuno, S. Otani, Y. Nishizawà","doi":"10.1161/01.ATV.0000024684.67566.45","DOIUrl":"https://doi.org/10.1161/01.ATV.0000024684.67566.45","url":null,"abstract":"Objectives—Platelet adherence and activation are associated with smooth muscle cell (SMC) proliferation and arterial restenosis. This study examined platelet-SMC interaction on fibrillar type I collagen and analyzed the role of thrombospondin (TSP)-1 in platelet-induced SMC proliferation. Methods and Results—When SMCs cultured on fibrillar collagen were treated with human platelets (5 preparations), 7.45±2.94% of the cells passed through S phase within 24 hours, as determined by bromodeoxyuridine nuclear labeling. The addition of platelets markedly induced SMC TSP-1 mRNA expression and cell surface protein accumulation, which colocalized with adhered platelets, as determined by &agr;IIb integrin immunostaining. Direct interaction of platelets with SMCs was necessary for its effect on proliferation and TSP-1 accumulation, as determined in the transwell culture system. The anti–TSP-1 blocking antibody strongly inhibited platelet-induced SMC proliferation by ≈60%. Analysis of the receptors for TSP-1 accumulation on the SMC surface revealed that &bgr;1 integrins are mainly involved. The anti–&bgr;1 integrin blocking antibody, which potently suppressed TSP-1 accumulation on SMCs, also markedly inhibited platelet-stimulated SMC proliferation. Conclusions—TSP-1 and &bgr;1 integrin interaction is involved in platelet-stimulated SMC proliferation. This in vitro coculture system could prove useful for examining the molecular mechanism underlying platelet-induced vascular remodeling and for studying the mechanism of a tested drug for restenosis.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84764014","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 : 2002-08-01DOI: 10.1161/01.ATV.0000025429.67378.65
Xiaoping Zhang, H. Tada, Ziping Wang, T. Hintze
Objective—This study investigated whether cAMP signal transduction regulates coronary microvascular NO production after heart failure (HF), a state in which endothelial NO synthase (eNOS) is downregulated. Methods and Results—Myocardial microvessels were isolated. Nitrite, the hydration product of NO, from these vessels was quantified by using the Griess reaction. Forskolin (10−4 mol/L), 8-bromo-cAMP (10−2 mol/L), isoproterenol (10−4 mol/L), or adrenomedullin (10−6 mol/L) significantly increased nitrite release by 78±8, 84±14, 71±11, and 73±15 pmol/mg, respectively, from isolated microvessels from normal canine hearts (P <0.05 versus control). Bradykinin (10−5 mol/L) and acetylcholine (10−5 mol/L) increased nitrite release by 83±13 and 72±6 pmol/mg, respectively (P <0.05 versus control). However, NO production induced by bradykinin and acetylcholine was markedly reduced after HF (46±7 and 39±7 pmol/mg, respectively;P <0.05 versus normal), reflecting eNOS downregulation (55% in eNOS protein). Surprisingly, NO production in response to forskolin, 8-bromo-cAMP, isoproterenol, and adrenomedullin not only was preserved but also was substantially enhanced in these microvessels after HF (121±14, 124±21, 107±18, and 122±16 pmol/mg, respectively;P <0.05 versus normal group) and was associated with an upregulation of protein kinase B (220% increase in protein kinase B protein). All these responses were in an NO synthase or a protein kinase A inhibitor–blockable manner. Conclusions—Our data indicate that cAMP signal transduction may be an important potential compensatory pathway to increase myocardial microvascular NO production after HF when eNOS is downregulated.
{"title":"cAMP Signal Transduction, A Potential Compensatory Pathway for Coronary Endothelial NO Production After Heart Failure","authors":"Xiaoping Zhang, H. Tada, Ziping Wang, T. Hintze","doi":"10.1161/01.ATV.0000025429.67378.65","DOIUrl":"https://doi.org/10.1161/01.ATV.0000025429.67378.65","url":null,"abstract":"Objective—This study investigated whether cAMP signal transduction regulates coronary microvascular NO production after heart failure (HF), a state in which endothelial NO synthase (eNOS) is downregulated. Methods and Results—Myocardial microvessels were isolated. Nitrite, the hydration product of NO, from these vessels was quantified by using the Griess reaction. Forskolin (10−4 mol/L), 8-bromo-cAMP (10−2 mol/L), isoproterenol (10−4 mol/L), or adrenomedullin (10−6 mol/L) significantly increased nitrite release by 78±8, 84±14, 71±11, and 73±15 pmol/mg, respectively, from isolated microvessels from normal canine hearts (P <0.05 versus control). Bradykinin (10−5 mol/L) and acetylcholine (10−5 mol/L) increased nitrite release by 83±13 and 72±6 pmol/mg, respectively (P <0.05 versus control). However, NO production induced by bradykinin and acetylcholine was markedly reduced after HF (46±7 and 39±7 pmol/mg, respectively;P <0.05 versus normal), reflecting eNOS downregulation (55% in eNOS protein). Surprisingly, NO production in response to forskolin, 8-bromo-cAMP, isoproterenol, and adrenomedullin not only was preserved but also was substantially enhanced in these microvessels after HF (121±14, 124±21, 107±18, and 122±16 pmol/mg, respectively;P <0.05 versus normal group) and was associated with an upregulation of protein kinase B (220% increase in protein kinase B protein). All these responses were in an NO synthase or a protein kinase A inhibitor–blockable manner. Conclusions—Our data indicate that cAMP signal transduction may be an important potential compensatory pathway to increase myocardial microvascular NO production after HF when eNOS is downregulated.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85392726","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 : 2002-08-01DOI: 10.1161/01.ATV.0000023438.32585.A1
K. Dreja, M. Voldstedlund, J. Vinten, J. Tranum-Jensen, P. Hellstrand, K. Swärd
Objective—This study assessed the role of cholesterol-rich membrane regions, including caveolae, in the regulation of arterial contractility. Methods and Results—Rat tail artery devoid of endothelium was treated with the cholesterol acceptor methyl-&bgr;-cyclodextrin, and the effects on force and Ca2+ handling were evaluated. In cholesterol-depleted preparations, the force responses to &agr;1-adrenergic receptors, membrane depolarization, inhibition of myosin light chain phosphatase, and activation of G proteins with a mixture of 20 mmol/L NaF and 60 &mgr;mol/L AlCl3 were unaffected. In contrast, responses to 5-hydroxytryptamine (5-HT), vasopressin, and endothelin were reduced by >50%. The rise in global intracellular free Ca2+ concentration in response to 5-HT was attenuated, as was the generation of Ca2+ waves at the cellular level. By electron microscopy, cholesterol depletion was found to disrupt caveolae. The 5-HT response could be restored by exogenous cholesterol, which also restored caveolae. Western blots showed that the levels of 5-HT2A receptor and of caveolin-1 were unaffected by cholesterol extraction. Sucrose gradient centrifugation showed enrichment of 5-HT2A receptors, but not &agr;1-adrenergic receptors, in the caveolin-1–containing fractions, suggesting localization of the former to caveolae. Conclusions—These results show that a subset of signaling pathways that regulate smooth muscle contraction depends specifically on cholesterol. Furthermore, the cholesterol-dependent step in serotonergic signaling occurs early in the pathway and depends on the integrity of caveolae.
{"title":"Cholesterol Depletion Disrupts Caveolae and Differentially Impairs Agonist-Induced Arterial Contraction","authors":"K. Dreja, M. Voldstedlund, J. Vinten, J. Tranum-Jensen, P. Hellstrand, K. Swärd","doi":"10.1161/01.ATV.0000023438.32585.A1","DOIUrl":"https://doi.org/10.1161/01.ATV.0000023438.32585.A1","url":null,"abstract":"Objective—This study assessed the role of cholesterol-rich membrane regions, including caveolae, in the regulation of arterial contractility. Methods and Results—Rat tail artery devoid of endothelium was treated with the cholesterol acceptor methyl-&bgr;-cyclodextrin, and the effects on force and Ca2+ handling were evaluated. In cholesterol-depleted preparations, the force responses to &agr;1-adrenergic receptors, membrane depolarization, inhibition of myosin light chain phosphatase, and activation of G proteins with a mixture of 20 mmol/L NaF and 60 &mgr;mol/L AlCl3 were unaffected. In contrast, responses to 5-hydroxytryptamine (5-HT), vasopressin, and endothelin were reduced by >50%. The rise in global intracellular free Ca2+ concentration in response to 5-HT was attenuated, as was the generation of Ca2+ waves at the cellular level. By electron microscopy, cholesterol depletion was found to disrupt caveolae. The 5-HT response could be restored by exogenous cholesterol, which also restored caveolae. Western blots showed that the levels of 5-HT2A receptor and of caveolin-1 were unaffected by cholesterol extraction. Sucrose gradient centrifugation showed enrichment of 5-HT2A receptors, but not &agr;1-adrenergic receptors, in the caveolin-1–containing fractions, suggesting localization of the former to caveolae. Conclusions—These results show that a subset of signaling pathways that regulate smooth muscle contraction depends specifically on cholesterol. Furthermore, the cholesterol-dependent step in serotonergic signaling occurs early in the pathway and depends on the integrity of caveolae.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88918066","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 : 2002-08-01DOI: 10.1161/01.ATV.0000024082.46387.38
N. K. Schiller, W. Boisvert, L. Curtiss
Objective—Natural killer (NK) cells have been identified in human vascular pathologies. In this study, we identified NK cells in aortic root atherosclerotic lesions of low density lipoprotein (LDL) receptor–deficient (LDLr−/−) mice. To characterize the role of NK cell–mediated cytolysis in atherosclerosis, we generated C57Bl/6 double-mutant mice by crossing LDLr−/− mice with NK cell–defective Lystbeige mice (creating beige,LDLr−/− mice) and with perforin-deficient mice (creating Pfp−/−,LDLr−/− mice). Methods and Results—Male mice (8 to 10 weeks old) were fed a high-fat diet to induce atherosclerosis. Compared with LDLr−/− mice, beige,LDLr−/− mice had impaired NK cell cytolytic activity and significantly increased atherosclerosis (P <0.05). Pfp−/−,LDLr−/− mice had impaired NK cell cytolytic activity, yet they had lesions that were similar to those of control mice. This suggested that NK cell cytolysis did not play a significant role in atherosclerosis and that the exacerbated atherosclerosis of the beige,LDLr−/− mouse was independent of impaired NK cell cytolytic activity. Therefore, we investigated the role of T and B lymphocytes in atherosclerosis of beige mice by crossing them with recombinase activator gene 1–deficient LDLr−/− mice (Rag1−/−,LDLr−/− mice), thus creating beige,Rag1−/−, LDLr−/− mice. As in the double-mutant study, beige,Rag1−/−,LDLr−/− mice had significantly increased lesions compared with Rag1−/−,LDLr−/− control mice. Conclusions—Therefore, the Lystbeige mutation in LDLr−/− mice has proatherogenic properties that are independent of NK cell–mediated cytolysis and lymphocyte-mediated acquired immunity.
{"title":"Inflammation in Atherosclerosis: Lesion Formation in LDL Receptor–Deficient Mice With Perforin and Lystbeige Mutations","authors":"N. K. Schiller, W. Boisvert, L. Curtiss","doi":"10.1161/01.ATV.0000024082.46387.38","DOIUrl":"https://doi.org/10.1161/01.ATV.0000024082.46387.38","url":null,"abstract":"Objective—Natural killer (NK) cells have been identified in human vascular pathologies. In this study, we identified NK cells in aortic root atherosclerotic lesions of low density lipoprotein (LDL) receptor–deficient (LDLr−/−) mice. To characterize the role of NK cell–mediated cytolysis in atherosclerosis, we generated C57Bl/6 double-mutant mice by crossing LDLr−/− mice with NK cell–defective Lystbeige mice (creating beige,LDLr−/− mice) and with perforin-deficient mice (creating Pfp−/−,LDLr−/− mice). Methods and Results—Male mice (8 to 10 weeks old) were fed a high-fat diet to induce atherosclerosis. Compared with LDLr−/− mice, beige,LDLr−/− mice had impaired NK cell cytolytic activity and significantly increased atherosclerosis (P <0.05). Pfp−/−,LDLr−/− mice had impaired NK cell cytolytic activity, yet they had lesions that were similar to those of control mice. This suggested that NK cell cytolysis did not play a significant role in atherosclerosis and that the exacerbated atherosclerosis of the beige,LDLr−/− mouse was independent of impaired NK cell cytolytic activity. Therefore, we investigated the role of T and B lymphocytes in atherosclerosis of beige mice by crossing them with recombinase activator gene 1–deficient LDLr−/− mice (Rag1−/−,LDLr−/− mice), thus creating beige,Rag1−/−, LDLr−/− mice. As in the double-mutant study, beige,Rag1−/−,LDLr−/− mice had significantly increased lesions compared with Rag1−/−,LDLr−/− control mice. Conclusions—Therefore, the Lystbeige mutation in LDLr−/− mice has proatherogenic properties that are independent of NK cell–mediated cytolysis and lymphocyte-mediated acquired immunity.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78773408","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 : 2002-08-01DOI: 10.1161/01.ATV.0000027102.53875.47
M. Sakakibara, S. Goto, K. Eto, N. Tamura, T. Isshiki, S. Handa
Objective—Factors influencing platelet accumulation around stents were to be investigated by an ex vivo flow chamber system. Methods and Results—Platelet accumulations on collagen surfaces under flow conditions were augmented in the presence of stents, especially at sites downstream from coil stents. Densitometric analysis revealed that 4.9±0.8 times more platelets accumulated downstream from coil stents than were formed downstream from tube stents (P <0.01), suggesting that stent morphology is an important determinant factor of its thrombogenicity. Platelet accumulations around stents were significantly inhibited by a combination of ticlopidine and aspirin, whereas aspirin alone produced only modest inhibition. Anti–glycoprotein IIb/IIIa (abciximab) inhibited platelet accumulation around stents in a dose-dependent manner, whereas the antibody blocking von Willebrand factor binding to glycoprotein Ib&agr;, which had been shown to inhibit platelet thrombus formation under high shear rates, did not inhibit the accumulation downstream from the coil stents. Our results suggest that the important characteristics of in vivo stent thrombosis, ie, augmented platelet accumulation with coil stents and the strong antithrombotic effect of the combination antiplatelet agents and an anti–glycoprotein IIb/IIIa, can be reproduced in ex vivo perfusion model. Conclusions—We conclude that an ex vivo perfusion system is useful in the assessment of the thrombogenicity of various stents and in the screening of effective antiplatelet agents.
{"title":"Application of Ex Vivo Flow Chamber System for Assessment of Stent Thrombosis","authors":"M. Sakakibara, S. Goto, K. Eto, N. Tamura, T. Isshiki, S. Handa","doi":"10.1161/01.ATV.0000027102.53875.47","DOIUrl":"https://doi.org/10.1161/01.ATV.0000027102.53875.47","url":null,"abstract":"Objective—Factors influencing platelet accumulation around stents were to be investigated by an ex vivo flow chamber system. Methods and Results—Platelet accumulations on collagen surfaces under flow conditions were augmented in the presence of stents, especially at sites downstream from coil stents. Densitometric analysis revealed that 4.9±0.8 times more platelets accumulated downstream from coil stents than were formed downstream from tube stents (P <0.01), suggesting that stent morphology is an important determinant factor of its thrombogenicity. Platelet accumulations around stents were significantly inhibited by a combination of ticlopidine and aspirin, whereas aspirin alone produced only modest inhibition. Anti–glycoprotein IIb/IIIa (abciximab) inhibited platelet accumulation around stents in a dose-dependent manner, whereas the antibody blocking von Willebrand factor binding to glycoprotein Ib&agr;, which had been shown to inhibit platelet thrombus formation under high shear rates, did not inhibit the accumulation downstream from the coil stents. Our results suggest that the important characteristics of in vivo stent thrombosis, ie, augmented platelet accumulation with coil stents and the strong antithrombotic effect of the combination antiplatelet agents and an anti–glycoprotein IIb/IIIa, can be reproduced in ex vivo perfusion model. Conclusions—We conclude that an ex vivo perfusion system is useful in the assessment of the thrombogenicity of various stents and in the screening of effective antiplatelet agents.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81010518","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 : 2002-08-01DOI: 10.1161/01.ATV.0000026613.18742.67
R. S. Smith, Kuei-Fu Lin, J. Agata, L. Chao, J. Chao
Objective—Endothelium-derived NO has been shown to mediate the mitogenic effect of vascular endothelial growth factor on cultured microvascular endothelium. To evaluate the role of endothelial NO synthase (eNOS) in angiogenesis in the ischemic hindlimb, we engineered an adenovirus containing human eNOS cDNA. Methods and Results—After gene transfer, expression of eNOS in cultured cells was detected by increased intracellular cGMP and nitrate/nitrite levels and NO synthase activity. Adenovirus containing either the eNOS or luciferase gene was injected into the adductor muscle of rat hindlimbs immediately after femoral artery removal. Human eNOS protein was detected throughout the course of the experiment by immunostaining. Significant increases in blood perfusion were monitored by laser Doppler imaging from 2 to 4 weeks after gene delivery in the ischemic hindlimb of rats receiving eNOS compared with control rats receiving the reporter gene. An increase in regional blood flow was also detected after eNOS gene transfer by a fluorescent microsphere assay. eNOS gene delivery in the ischemic hindlimb resulted in significant increases in intracellular cGMP levels and in capillary density identified by anti–CD-31 immunostaining. Angiogenesis was further confirmed in mice after eNOS gene transfer by increased hemoglobin content in Matrigel implants. Conclusions—Taken together, these results indicate that eNOS enhances angiogenesis and raises the potential of eNOS gene transfer for modulation of vascular insufficiency.
{"title":"Human Endothelial Nitric Oxide Synthase Gene Delivery Promotes Angiogenesis in a Rat Model of Hindlimb Ischemia","authors":"R. S. Smith, Kuei-Fu Lin, J. Agata, L. Chao, J. Chao","doi":"10.1161/01.ATV.0000026613.18742.67","DOIUrl":"https://doi.org/10.1161/01.ATV.0000026613.18742.67","url":null,"abstract":"Objective—Endothelium-derived NO has been shown to mediate the mitogenic effect of vascular endothelial growth factor on cultured microvascular endothelium. To evaluate the role of endothelial NO synthase (eNOS) in angiogenesis in the ischemic hindlimb, we engineered an adenovirus containing human eNOS cDNA. Methods and Results—After gene transfer, expression of eNOS in cultured cells was detected by increased intracellular cGMP and nitrate/nitrite levels and NO synthase activity. Adenovirus containing either the eNOS or luciferase gene was injected into the adductor muscle of rat hindlimbs immediately after femoral artery removal. Human eNOS protein was detected throughout the course of the experiment by immunostaining. Significant increases in blood perfusion were monitored by laser Doppler imaging from 2 to 4 weeks after gene delivery in the ischemic hindlimb of rats receiving eNOS compared with control rats receiving the reporter gene. An increase in regional blood flow was also detected after eNOS gene transfer by a fluorescent microsphere assay. eNOS gene delivery in the ischemic hindlimb resulted in significant increases in intracellular cGMP levels and in capillary density identified by anti–CD-31 immunostaining. Angiogenesis was further confirmed in mice after eNOS gene transfer by increased hemoglobin content in Matrigel implants. Conclusions—Taken together, these results indicate that eNOS enhances angiogenesis and raises the potential of eNOS gene transfer for modulation of vascular insufficiency.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89614771","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 : 2002-08-01DOI: 10.1161/01.ATV.0000026298.00663.58
Shokei Kim, Y. Izumi, Yasuhiro Izumiya, Y. Zhan, M. Taniguchi, H. Iwao
Objective—The present study was undertaken to elucidate the effect of the ACE inhibitor and the angiotensin II type 1 (AT1) receptor antagonist in combination on neointimal hyperplasia after balloon injury. Methods and Results—Temocapril (an ACE inhibitor), CS-866 (an AT1 receptor antagonist), or their combination was given orally to rats, and their effects were compared on vascular hyperplasia induced by balloon injury. The maximal preventive effect of temocapril and CS-866 alone on neointimal thickening after balloon injury was obtained at a dose of 20 and 10 mg/kg per day, respectively. However, compared with either agent alone, combined temocapril and CS-866 (20 and 10 mg/kg per day, respectively) prevented intimal thickening to a larger extent. Furthermore, compared with either agent alone, combined temocapril and CS-866 prevented vascular smooth muscle cell proliferation in the intima more potently. The increase in platelet-derived growth factor receptor tyrosyl phosphorylation was reduced more potently by the combination of both agents compared with either agent alone. The nonpeptide bradykinin B2 receptor antagonist or the NO synthase inhibitor reduced the prevention of intimal thickening by combined temocapril and CS-866. Conclusions—Compared with either agent alone, the combination of an ACE inhibitor and an AT1 receptor antagonist is more effective in the prevention of vascular hyperplasia due to bradykinin or NO.
{"title":"Beneficial Effects of Combined Blockade of ACE and AT1 Receptor on Intimal Hyperplasia in Balloon-Injured Rat Artery","authors":"Shokei Kim, Y. Izumi, Yasuhiro Izumiya, Y. Zhan, M. Taniguchi, H. Iwao","doi":"10.1161/01.ATV.0000026298.00663.58","DOIUrl":"https://doi.org/10.1161/01.ATV.0000026298.00663.58","url":null,"abstract":"Objective—The present study was undertaken to elucidate the effect of the ACE inhibitor and the angiotensin II type 1 (AT1) receptor antagonist in combination on neointimal hyperplasia after balloon injury. Methods and Results—Temocapril (an ACE inhibitor), CS-866 (an AT1 receptor antagonist), or their combination was given orally to rats, and their effects were compared on vascular hyperplasia induced by balloon injury. The maximal preventive effect of temocapril and CS-866 alone on neointimal thickening after balloon injury was obtained at a dose of 20 and 10 mg/kg per day, respectively. However, compared with either agent alone, combined temocapril and CS-866 (20 and 10 mg/kg per day, respectively) prevented intimal thickening to a larger extent. Furthermore, compared with either agent alone, combined temocapril and CS-866 prevented vascular smooth muscle cell proliferation in the intima more potently. The increase in platelet-derived growth factor receptor tyrosyl phosphorylation was reduced more potently by the combination of both agents compared with either agent alone. The nonpeptide bradykinin B2 receptor antagonist or the NO synthase inhibitor reduced the prevention of intimal thickening by combined temocapril and CS-866. Conclusions—Compared with either agent alone, the combination of an ACE inhibitor and an AT1 receptor antagonist is more effective in the prevention of vascular hyperplasia due to bradykinin or NO.","PeriodicalId":8418,"journal":{"name":"Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86031591","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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