Pub Date : 2001-01-01DOI: 10.3109/10623320109063153
S. Frangos, R. Knox, Y. Yano, E. Chen, G. Di Luozzo, A. H. Chen, B. Sumpio
The irregular distribution of plaque in the vasculature results from the interaction of local hemodynamic forces with the vessel wall. One well-characterized force is cyclic circumferential strain, the repetitive pulsatile pressure distention on the arterial wall. This review summarizes current research, which has aimed to elicit the signal transduction pathway by which cyclic strain elicits functional and structural responses in endothelial cells; specifically, it summarizes the signaling pathway that begins with the reorganization of integrins. One method by which these extracellular matrix receptors affect signal transduction is through their ability to initiate the process of phosphorylation on tyrosine residues of cytoplasmic protein kinases, including focal adhesion kinase. The strain-induced pathway appears to also involve ras and the mitogen-activated protein kinase family of enzymes, and preliminary data suggests a role for src as well. Ultimately, it is the regulation of gene expression through the modulation of transcription factors that allows endothelial cells to respond to changes in local hemodynamics.
{"title":"The integrin-mediated cyclic strain-induced signaling pathway in vascular endothelial cells.","authors":"S. Frangos, R. Knox, Y. Yano, E. Chen, G. Di Luozzo, A. H. Chen, B. Sumpio","doi":"10.3109/10623320109063153","DOIUrl":"https://doi.org/10.3109/10623320109063153","url":null,"abstract":"The irregular distribution of plaque in the vasculature results from the interaction of local hemodynamic forces with the vessel wall. One well-characterized force is cyclic circumferential strain, the repetitive pulsatile pressure distention on the arterial wall. This review summarizes current research, which has aimed to elicit the signal transduction pathway by which cyclic strain elicits functional and structural responses in endothelial cells; specifically, it summarizes the signaling pathway that begins with the reorganization of integrins. One method by which these extracellular matrix receptors affect signal transduction is through their ability to initiate the process of phosphorylation on tyrosine residues of cytoplasmic protein kinases, including focal adhesion kinase. The strain-induced pathway appears to also involve ras and the mitogen-activated protein kinase family of enzymes, and preliminary data suggests a role for src as well. Ultimately, it is the regulation of gene expression through the modulation of transcription factors that allows endothelial cells to respond to changes in local hemodynamics.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"22 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91532492","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 : 2001-01-01DOI: 10.3109/10623320109051564
E. Papadimitriou, C. R. Waters, V. Manolopoulos, B. Unsworth, M. Maragoudakis, P. Lelkes
We previously reported that short-term exposure of cultured rat adrenal medullary endothelial cells (RAMEC) to thrombin enhances the subendothelial deposition of extracellular matrix (ECM) proteins fibronectin, laminin, and collagen types I (C-I) and IV (C-IV) (Papadimitriou et al. 1997). In this work, we extended our previous studies on factors that effect ECM protein deposition to include agents that activate or inhibit some of the most common intracellular signals such as cAMP, protein kinase C (PKC), and calcium. Furthermore, we investigated the possible link between the observed alterations in ECM protein deposition and the secretion of matrix metalloproteinase-2 (MMP-2). Forskolin (adenylyl cyclase activator) caused a dose-dependent increase in the deposition of all four ECM proteins studied. Isoproterenol beta-adrenergic receptor agonist) and the membrane permeant cAMP analogue dibutyryl-cAMP significantly increased the deposited amounts of ECM proteins at low concentrations, and this increase was reversed at higher concentrations of both agents. All these agents had the opposite effect on MMP-2 secretion, increasing it at doses where they decreased ECM protein deposition and vice versa. However, elevation of cAMP by the phosphodiesterase inhibitor IBMX had no effect either on the deposited amounts of any of the ECM proteins studied or on MMP-2 secretion. Activation of PKC by phorbol ester (PMA) resulted in a decrease in ECM protein deposition and an increase in MMP-2 secretion. Finally, chelation of intercellular calcium with BAPTA-AM resulted in an increased ECM deposition and a decrease in MMP-2 secretion. Our results show a complex pattern of regulation of ECM protein deposition by cAMP-mobilizing agents and also indicate an inverse correlation between ECM protein deposition and secretion of MMP-2. The concerted regulation of both of these processes is essential in the formation of new blood vessels, and for the integrity of the vascular wall.
{"title":"Regulation of extracellular matrix remodeling and MMP-2 activation in cultured rat adrenal medullary endothelial cells.","authors":"E. Papadimitriou, C. R. Waters, V. Manolopoulos, B. Unsworth, M. Maragoudakis, P. Lelkes","doi":"10.3109/10623320109051564","DOIUrl":"https://doi.org/10.3109/10623320109051564","url":null,"abstract":"We previously reported that short-term exposure of cultured rat adrenal medullary endothelial cells (RAMEC) to thrombin enhances the subendothelial deposition of extracellular matrix (ECM) proteins fibronectin, laminin, and collagen types I (C-I) and IV (C-IV) (Papadimitriou et al. 1997). In this work, we extended our previous studies on factors that effect ECM protein deposition to include agents that activate or inhibit some of the most common intracellular signals such as cAMP, protein kinase C (PKC), and calcium. Furthermore, we investigated the possible link between the observed alterations in ECM protein deposition and the secretion of matrix metalloproteinase-2 (MMP-2). Forskolin (adenylyl cyclase activator) caused a dose-dependent increase in the deposition of all four ECM proteins studied. Isoproterenol beta-adrenergic receptor agonist) and the membrane permeant cAMP analogue dibutyryl-cAMP significantly increased the deposited amounts of ECM proteins at low concentrations, and this increase was reversed at higher concentrations of both agents. All these agents had the opposite effect on MMP-2 secretion, increasing it at doses where they decreased ECM protein deposition and vice versa. However, elevation of cAMP by the phosphodiesterase inhibitor IBMX had no effect either on the deposited amounts of any of the ECM proteins studied or on MMP-2 secretion. Activation of PKC by phorbol ester (PMA) resulted in a decrease in ECM protein deposition and an increase in MMP-2 secretion. Finally, chelation of intercellular calcium with BAPTA-AM resulted in an increased ECM deposition and a decrease in MMP-2 secretion. Our results show a complex pattern of regulation of ECM protein deposition by cAMP-mobilizing agents and also indicate an inverse correlation between ECM protein deposition and secretion of MMP-2. The concerted regulation of both of these processes is essential in the formation of new blood vessels, and for the integrity of the vascular wall.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"62 1","pages":"243-53"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76208124","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 : 2001-01-01DOI: 10.3109/10623320109063158
M. Rusnati, C. Urbinati, B. Musulin, D. Ribatti, A. Albini, D. Noonan, C. Marchisone, J. Waltenberger, M. Presta
Extracellular Tat protein, the transactivating factor of the human immunodeficiency virus type 1 (HIV-1), modulates gene expression, growth, and angiogenic activity in endothelial cells by interacting with the vascular endothelial growth factor (VEGF) receptor-2 (Flk-1/KDR). Recombinant Tat protein, produced as glutathione-S-transferase chimera (GST-Tat), activates mitogen-activated protein kinase (MAPK) ERK(1/2) in human, murine, and bovine endothelial cells whereas GST is ineffective. In bovine aortic endothelial cells, GST-Tat and the 165 amino acid VEGF isoform (VEGF165) induce transient ERK(1/2) phosphorylation with similar potency and kinetics. The synthetic peptide Tat(41-60), but not peptides Tat(1-21) and Tat(71-86), causes ERK(1/2) phosphorylation, thus implicating Tat/KDR interaction in the activation of this signalling pathway. Accordingly, GST-Tat induces ERK(1/2) phosphorylation in KDR-transfected porcine aortic endothelial cells but not in parental cells. MAPK kinase inhibitors PD098059 and U0126 prevent ERK(1/2) phosphorylation by Tat. However, they do not affect the angiogenic activity exerted by Tat in the murine Matrigel plug and chick embryo chorioallantoic membrane assays. Blocking of MAPK kinase activity impairs instead the angiogenic response to VEGF165 and to fibroblast growth factor-2 (FGF-2). Our data demonstrate that ERK(1/2) activation following the interaction of HIV-1 Tat protein with endothelial cell Flk-1/KDR receptor does not represent an absolute requirement for a full angiogenic response to this growth factor that appears to utilize mechanism(s) at least in part distinct from those triggered by other prototypic angiogenic growth factors.
{"title":"Activation of endothelial cell mitogen activated protein kinase ERK(1/2) by extracellular HIV-1 Tat protein.","authors":"M. Rusnati, C. Urbinati, B. Musulin, D. Ribatti, A. Albini, D. Noonan, C. Marchisone, J. Waltenberger, M. Presta","doi":"10.3109/10623320109063158","DOIUrl":"https://doi.org/10.3109/10623320109063158","url":null,"abstract":"Extracellular Tat protein, the transactivating factor of the human immunodeficiency virus type 1 (HIV-1), modulates gene expression, growth, and angiogenic activity in endothelial cells by interacting with the vascular endothelial growth factor (VEGF) receptor-2 (Flk-1/KDR). Recombinant Tat protein, produced as glutathione-S-transferase chimera (GST-Tat), activates mitogen-activated protein kinase (MAPK) ERK(1/2) in human, murine, and bovine endothelial cells whereas GST is ineffective. In bovine aortic endothelial cells, GST-Tat and the 165 amino acid VEGF isoform (VEGF165) induce transient ERK(1/2) phosphorylation with similar potency and kinetics. The synthetic peptide Tat(41-60), but not peptides Tat(1-21) and Tat(71-86), causes ERK(1/2) phosphorylation, thus implicating Tat/KDR interaction in the activation of this signalling pathway. Accordingly, GST-Tat induces ERK(1/2) phosphorylation in KDR-transfected porcine aortic endothelial cells but not in parental cells. MAPK kinase inhibitors PD098059 and U0126 prevent ERK(1/2) phosphorylation by Tat. However, they do not affect the angiogenic activity exerted by Tat in the murine Matrigel plug and chick embryo chorioallantoic membrane assays. Blocking of MAPK kinase activity impairs instead the angiogenic response to VEGF165 and to fibroblast growth factor-2 (FGF-2). Our data demonstrate that ERK(1/2) activation following the interaction of HIV-1 Tat protein with endothelial cell Flk-1/KDR receptor does not represent an absolute requirement for a full angiogenic response to this growth factor that appears to utilize mechanism(s) at least in part distinct from those triggered by other prototypic angiogenic growth factors.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"116 1","pages":"65-74"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80277526","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 : 2001-01-01DOI: 10.3109/10623320109165323
P. Barbeau, K. Woods, L. Ramsey, M. Litaker, D. Pollock, J. Pollock, L. Callahan, A. Kutlar, G. Mensah, B. Gutin
The aim of this study was to determine the response of inflammatory and vasoactive mediators to 3 consecutive days of exercise in African-American women with and without sickle cell anemia (SCA). Circulating inflammatory mediators [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha)] were measured before, and vasoactive mediators [endothelin-1 (ET-1), nitric oxide metabolites (NOx)] before and after each exercise bout in ten subjects with SCA and ten controls. Exercise did not affect ET-1, IL-6 or CRP concentrations (p >.05). TNFalpha was higher in SCA than controls (p < or = .0005) at all times; however, the response pattern was similar for the groups: no change from day 1 to day 2, but a decrease from day 2 to day 3 (p < or = .05). NOx increased significantly after exercise (p < or = .0001) but returned to baseline by 24 h afterward. On the 3rd day, NOx increased after exercise in SCA but not in the controls (p < or = .05). In conclusion, exercise did not cause a harmful inflammatory response in these individuals with SCA. However, NOx increased after exercise on all 3 days in SCA but appeared attenuated after 2 days in controls.
本研究的目的是确定炎症和血管活性介质对患有和不患有镰状细胞性贫血(SCA)的非裔美国妇女连续3天运动的反应。测定10例SCA患者和10例对照组每次运动前后循环炎症介质[c反应蛋白(CRP)、白细胞介素-6 (IL-6)、肿瘤坏死因子α (TNFalpha)]和血管活性介质[内皮素-1 (ET-1)、一氧化氮代谢物(NOx)]的含量。运动不影响ET-1、IL-6和CRP浓度(p > 0.05)。SCA患者的TNFalpha在任何时候都高于对照组(p < or = 0.0005);然而，各组的反应模式相似:从第1天到第2天没有变化，但从第2天到第3天有所下降(p <或= 0.05)。运动后NOx显著增加(p < or = 0.0001)，但24小时后恢复到基线水平。在第3天，SCA组运动后NOx增加，而对照组没有(p <或= 0.05)。总之，运动不会引起SCA患者有害的炎症反应。然而，在SCA组中，NOx在运动后3天均有所增加，而在对照组中，NOx在运动后2天出现减弱。
{"title":"Exercise in sickle cell anemia: effect on inflammatory and vasoactive mediators.","authors":"P. Barbeau, K. Woods, L. Ramsey, M. Litaker, D. Pollock, J. Pollock, L. Callahan, A. Kutlar, G. Mensah, B. Gutin","doi":"10.3109/10623320109165323","DOIUrl":"https://doi.org/10.3109/10623320109165323","url":null,"abstract":"The aim of this study was to determine the response of inflammatory and vasoactive mediators to 3 consecutive days of exercise in African-American women with and without sickle cell anemia (SCA). Circulating inflammatory mediators [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha)] were measured before, and vasoactive mediators [endothelin-1 (ET-1), nitric oxide metabolites (NOx)] before and after each exercise bout in ten subjects with SCA and ten controls. Exercise did not affect ET-1, IL-6 or CRP concentrations (p >.05). TNFalpha was higher in SCA than controls (p < or = .0005) at all times; however, the response pattern was similar for the groups: no change from day 1 to day 2, but a decrease from day 2 to day 3 (p < or = .05). NOx increased significantly after exercise (p < or = .0001) but returned to baseline by 24 h afterward. On the 3rd day, NOx increased after exercise in SCA but not in the controls (p < or = .05). In conclusion, exercise did not cause a harmful inflammatory response in these individuals with SCA. However, NOx increased after exercise on all 3 days in SCA but appeared attenuated after 2 days in controls.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"42 1","pages":"147-55"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77936045","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 : 2001-01-01DOI: 10.3109/10623320109063156
J. Smith, N. Davies, A. I. Willis, B. Sumpio, P. Zilla
OBJECTIVE Accumulating evidence links the release of vascular endothelial growth factor (VEGF) by vascular smooth muscle cells (VSMC) to normal endothelial cell (EC) function, repair and maintenance. Using an in vitro model we investigate the role of cyclic stretch on both the release of VEGF by VSMC and the phosphorylation of a VEGF receptor on EC. METHODS Bovine VSMC and EC were exposed to 10% cyclic strain for 4 hours. VEGF mRNA steady-state levels of VSMC were analysed by northern blot hybridisation. The presence of secreted VEGF from VSMC was determined by assaying the migration of EC. VEGF receptor phosphorylation on stretched EC was assayed by immunoblotting. RESULTS The steady-state level of VEGF mRNA in stretched VSMC increased 3.3 (+/- 0.6) fold above that of unstretched VSMC (p < 0.005). Migration of EC was stimulated 8.3 (+/- 1.1) and 14.6 (+/- 1.3) fold by media from unstretched and stretched VSMC respectively, demonstrating a 1.8 fold increase due to stretch alone (p < 0.05). Cyclic stretch resulted in phosphorylation of the VEGF receptor KDR. CONCLUSION Exposure of VSMC to physiological levels of stretch induces a biologically significant increase in VEGF secretion and may provide an arterial stimulus for maintenance of steady state levels of VEGF essential for EC survival.
{"title":"Cyclic stretch induces the expression of vascular endothelial growth factor in vascular smooth muscle cells.","authors":"J. Smith, N. Davies, A. I. Willis, B. Sumpio, P. Zilla","doi":"10.3109/10623320109063156","DOIUrl":"https://doi.org/10.3109/10623320109063156","url":null,"abstract":"OBJECTIVE Accumulating evidence links the release of vascular endothelial growth factor (VEGF) by vascular smooth muscle cells (VSMC) to normal endothelial cell (EC) function, repair and maintenance. Using an in vitro model we investigate the role of cyclic stretch on both the release of VEGF by VSMC and the phosphorylation of a VEGF receptor on EC. METHODS Bovine VSMC and EC were exposed to 10% cyclic strain for 4 hours. VEGF mRNA steady-state levels of VSMC were analysed by northern blot hybridisation. The presence of secreted VEGF from VSMC was determined by assaying the migration of EC. VEGF receptor phosphorylation on stretched EC was assayed by immunoblotting. RESULTS The steady-state level of VEGF mRNA in stretched VSMC increased 3.3 (+/- 0.6) fold above that of unstretched VSMC (p < 0.005). Migration of EC was stimulated 8.3 (+/- 1.1) and 14.6 (+/- 1.3) fold by media from unstretched and stretched VSMC respectively, demonstrating a 1.8 fold increase due to stretch alone (p < 0.05). Cyclic stretch resulted in phosphorylation of the VEGF receptor KDR. CONCLUSION Exposure of VSMC to physiological levels of stretch induces a biologically significant increase in VEGF secretion and may provide an arterial stimulus for maintenance of steady state levels of VEGF essential for EC survival.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"5 1","pages":"41-8"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82326959","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 : 2001-01-01DOI: 10.1080/10623320109051563
L. Jornot, H. Petersen, M. Lusky, A. Pavirani, I. Moix, Morris, T. Rochat
Adenoviral vectors are promising tools for pulmonary vascular gene transfer. In first generation vectors, the viral E4 region is preserved (E4+ Ad), but E4 is deleted in second generation vectors (E4- Ad). These vectors were compared for their toxicity in human endothelial cells in terms of apoptosis and necrosis. Infection with E4+ Ad vectors reduced whereas E4- Ad vectors enhanced apoptosis under normal culture conditions. Furthermore, E4+ Ad protected against apoptosis induced by growth factor deprivation, while E4- Ad enhanced apoptosis triggered by ceramide. Ad vectors containing different E4 open reading frames, alone or in different combinations, showed similar effects to E4- Ad, leaving the viral genes that might be responsible for reducing apoptosis unidentified at the present time. As previously observed with E4+ Ad devoid of transgene, E4+ Ad carrying beta-galactosidase or green fluorescent protein under the control of either the RSV or CMV promoter also reduced apoptosis triggered by growth factor deprivation. In contrast, E4+ Ad containing a CFTR expression cassette did not reduce apoptosis, and E4- Ad with CFFR showed increased toxicity. We conclude that Ad vectors may have important effects on the control of apoptosis in transfected cells, depending on the residual expression of viral genes. This effect can be complicated by the action of transgene expression on cell survival.
{"title":"Effects of first generation E1E3-deleted and second generation E1E3E4-deleted/modified adenovirus vectors on human endothelial cell death.","authors":"L. Jornot, H. Petersen, M. Lusky, A. Pavirani, I. Moix, Morris, T. Rochat","doi":"10.1080/10623320109051563","DOIUrl":"https://doi.org/10.1080/10623320109051563","url":null,"abstract":"Adenoviral vectors are promising tools for pulmonary vascular gene transfer. In first generation vectors, the viral E4 region is preserved (E4+ Ad), but E4 is deleted in second generation vectors (E4- Ad). These vectors were compared for their toxicity in human endothelial cells in terms of apoptosis and necrosis. Infection with E4+ Ad vectors reduced whereas E4- Ad vectors enhanced apoptosis under normal culture conditions. Furthermore, E4+ Ad protected against apoptosis induced by growth factor deprivation, while E4- Ad enhanced apoptosis triggered by ceramide. Ad vectors containing different E4 open reading frames, alone or in different combinations, showed similar effects to E4- Ad, leaving the viral genes that might be responsible for reducing apoptosis unidentified at the present time. As previously observed with E4+ Ad devoid of transgene, E4+ Ad carrying beta-galactosidase or green fluorescent protein under the control of either the RSV or CMV promoter also reduced apoptosis triggered by growth factor deprivation. In contrast, E4+ Ad containing a CFTR expression cassette did not reduce apoptosis, and E4- Ad with CFFR showed increased toxicity. We conclude that Ad vectors may have important effects on the control of apoptosis in transfected cells, depending on the residual expression of viral genes. This effect can be complicated by the action of transgene expression on cell survival.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"42 1","pages":"167-79"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84826259","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 : 2001-01-01DOI: 10.3109/10623320109090801
E. Papadimitriou, C. R. Waters, V. Manolopoulos, B. Unsworth, M. Maragoudakis, P. L. Lelkes
We previously reported that short term exposure of cultured rat adrenal medullary endothelial cells (RAMEC) to thrombin enhances the subendothelial deposition of extracellular matrix (ECM) proteins fibronectin, laminin, and collagen types I (C-I) and IV (C-IV) (Papadimitriou et at., 1997). In this work, we extended our previous studies on factors that affect ECM protein deposition to include agents that activate or inhibit some of the most common intracellular signals such as cAMP, protein kinase C (PKC) and calcium. Furthemore, we investigated the possible link between the observed alterations in ECM protein deposition and the secretion of matrix metalloproteinase-2 (MMP-2). Forskolin (adenylyl cyclase activator) caused a dose-dependent increase in the deposition of all four ECM proteins studied. Isoproterenol (beta-adrenergic receptor agonist) and the membrane-permeant cAMP analogue dibutyryl-cAMP, significantly increased the deposited amounts of ECM proteins at low concentrations, and this increase was reversed at higher concentrations of both agents. All these agents had the opposite effect on MMP-2 secretion, increasing it at doses where they decreased ECM protein deposition and vice-versa. However, elevation of cAMP by the phosphodiesterase inhibitor IBMX had no effect neither on the deposited amounts of any of the ECM proteins studied nor on MMP-2 secretion. Activation of PKC by phorbol ester (PMA) resulted in a decrease in ECM protein deposition and an increase in MMP-2 secretion. Finally, chelation of intercellular calcium with BAPTA-AM resulted in an increased ECM deposition and a decrease in MMP-2 secretion, Our results show a complex pattern of regulation of ECM protein deposition by cAMP-mobilizing agents, and also indicate an inverse correlation between ECM protein deposition and secretion of MMP-2. The concerted regulation of both these processes is essential in the formation of new blood vessels and for the integrity of the vascular wall.
{"title":"Regulation of extracellular matrix remodeling and MMP-2 activation in cultured rat adrenal medullary endothelial cells.","authors":"E. Papadimitriou, C. R. Waters, V. Manolopoulos, B. Unsworth, M. Maragoudakis, P. L. Lelkes","doi":"10.3109/10623320109090801","DOIUrl":"https://doi.org/10.3109/10623320109090801","url":null,"abstract":"We previously reported that short term exposure of cultured rat adrenal medullary endothelial cells (RAMEC) to thrombin enhances the subendothelial deposition of extracellular matrix (ECM) proteins fibronectin, laminin, and collagen types I (C-I) and IV (C-IV) (Papadimitriou et at., 1997). In this work, we extended our previous studies on factors that affect ECM protein deposition to include agents that activate or inhibit some of the most common intracellular signals such as cAMP, protein kinase C (PKC) and calcium. Furthemore, we investigated the possible link between the observed alterations in ECM protein deposition and the secretion of matrix metalloproteinase-2 (MMP-2). Forskolin (adenylyl cyclase activator) caused a dose-dependent increase in the deposition of all four ECM proteins studied. Isoproterenol (beta-adrenergic receptor agonist) and the membrane-permeant cAMP analogue dibutyryl-cAMP, significantly increased the deposited amounts of ECM proteins at low concentrations, and this increase was reversed at higher concentrations of both agents. All these agents had the opposite effect on MMP-2 secretion, increasing it at doses where they decreased ECM protein deposition and vice-versa. However, elevation of cAMP by the phosphodiesterase inhibitor IBMX had no effect neither on the deposited amounts of any of the ECM proteins studied nor on MMP-2 secretion. Activation of PKC by phorbol ester (PMA) resulted in a decrease in ECM protein deposition and an increase in MMP-2 secretion. Finally, chelation of intercellular calcium with BAPTA-AM resulted in an increased ECM deposition and a decrease in MMP-2 secretion, Our results show a complex pattern of regulation of ECM protein deposition by cAMP-mobilizing agents, and also indicate an inverse correlation between ECM protein deposition and secretion of MMP-2. The concerted regulation of both these processes is essential in the formation of new blood vessels and for the integrity of the vascular wall.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"72 1","pages":"181-94"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85829159","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 : 2000-01-01DOI: 10.3109/10623320009072210
David S. Chi, Jason L. Henry, J. Kelley, Rebecca Thorpe, Smith Jk, G. Krishnaswamy
Endothelial dysfunction and/or injury is pivotal to the development of cardiovascular and inflammatory pathology. Endothelial dysfunction and/or injury has been described in Human Immunodeficiency Virus (HIV) infection. Elaboration of circulating markers of endothelial activation, such as soluble adhesion molecules and procoagulant proteins, occurs in HIV infection. Certain endothelial cells, such as those lining liver sinusoids, human umbilical vein endothelial cells, bone marrow stromal endothelial cells or brain microvascular endothelial cells, have been shown to be variably permissive for HIV infection. Entry of virus into endothelial cells may occur via CD4 antigen or galactosyl-ceramide receptors. Other mechanisms of entry including chemokine receptors have been proposed. Nevertheless, endothelial activation may also occur in HIV infection either by cytokines secreted in response to mononuclear or adventitial cell activation by virus or else by the effects of the secreted HIV-associated proteins, gp 120 (envelope glycoprotein) and Tat (transactivator of viral replication) on endothelium. Enhanced adhesiveness of endothelial cells, endothelial cell proliferation and apoptosis as well as activation of cytokine secretion have all been demonstrated. Synergy between select inflammatory cytokines and viral proteins in inducing endothelial injury has been shown. In HIV infection, dysfunctional or injured endothelial cells potentiate tissue injury, inflammation and remodeling, and accelerate the development of cardiovascular disease.
{"title":"The effects of HIV infection on endothelial function.","authors":"David S. Chi, Jason L. Henry, J. Kelley, Rebecca Thorpe, Smith Jk, G. Krishnaswamy","doi":"10.3109/10623320009072210","DOIUrl":"https://doi.org/10.3109/10623320009072210","url":null,"abstract":"Endothelial dysfunction and/or injury is pivotal to the development of cardiovascular and inflammatory pathology. Endothelial dysfunction and/or injury has been described in Human Immunodeficiency Virus (HIV) infection. Elaboration of circulating markers of endothelial activation, such as soluble adhesion molecules and procoagulant proteins, occurs in HIV infection. Certain endothelial cells, such as those lining liver sinusoids, human umbilical vein endothelial cells, bone marrow stromal endothelial cells or brain microvascular endothelial cells, have been shown to be variably permissive for HIV infection. Entry of virus into endothelial cells may occur via CD4 antigen or galactosyl-ceramide receptors. Other mechanisms of entry including chemokine receptors have been proposed. Nevertheless, endothelial activation may also occur in HIV infection either by cytokines secreted in response to mononuclear or adventitial cell activation by virus or else by the effects of the secreted HIV-associated proteins, gp 120 (envelope glycoprotein) and Tat (transactivator of viral replication) on endothelium. Enhanced adhesiveness of endothelial cells, endothelial cell proliferation and apoptosis as well as activation of cytokine secretion have all been demonstrated. Synergy between select inflammatory cytokines and viral proteins in inducing endothelial injury has been shown. In HIV infection, dysfunctional or injured endothelial cells potentiate tissue injury, inflammation and remodeling, and accelerate the development of cardiovascular disease.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"48 1","pages":"223-42"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87875243","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 : 2000-01-01DOI: 10.3109/10623320009072212
G. Rubanyi, A. Freay, R. Lawn
Elevated plasma level of lipoprotein(a) (Lp(a)) is a well established risk factor for premature atherosclerosis and coronary artery disease. Recent studies showed impaired endothelium-dependent vasodilatation in humans with elevated plasma Lp(a). However, these human studies could not determine whether (1) elevated Lp(a) levels alone are the cause of endothelial dysfunction (these patients had multiple risk factors), and (2) native or oxidatively modified Lp(a) contributes to endothelial dysfunction (no measurements of native/oxidized Lp(a) ratio was reported in humans). In order to test whether apo(a) (an essential component of Lp(a) which is required for binding to endothelial cells) and native Lp(a) cause endothelial dysfunction, in the present study we tested endothelium-dependent vasorelaxation in aortic rings isolated from control and transgenic male mice either expressing the human apo(a) gene (TgA) or both the human apo(a) and human apo B100 genes (TgL). The TgA mice had plasma apo(a) levels of 8.8 +/- 1.2 mg/dl (n=6) and the double transgenic TgL mice had plasma Lp(a) levels of 15.3 +/- 1.4 mg/dl (n=8). Isolated aortic rings with and without endothelium were mounted in organ chambers and contracted with U46619 (10(-8) M) in the presence of ibuprofen (10(-5) M). Acetylcholine caused concentration-dependent (10(-9)-10(-5) M) relaxation, which could be prevented by endothelium removal and by NG-L-nitro-arginine (10(-4) M). Basal and acetylcholine-stimulated endothelium-dependent relaxation and endothelium-independent relaxation to nitroglycerin (10(-6) M) were not significantly different in aortic rings isolated from control and TgA or TgL mice. Twenty-four hour incubation of aortic rings isolated from control mice with recombinant human apo(a) or native Lp(a) (up to 300 microg/ml) caused no impairment of endothelium-dependent relaxations. In contrast, incubation with oxidized Lp(a) (50 microg/ml) or oxidized LDL (250 microg/ml) caused significant suppression of acetylcholine-induced endothelium-dependent vasorelaxation. These results show for the first time that elevated plasma levels of apo(a) and Lp(a) do not cause endothelial dysfunction in transgenic mice.
{"title":"Endothelium-dependent vasorelaxation in the aorta of transgenic mice expressing human apolipoprotein(a) or lipoprotein(a).","authors":"G. Rubanyi, A. Freay, R. Lawn","doi":"10.3109/10623320009072212","DOIUrl":"https://doi.org/10.3109/10623320009072212","url":null,"abstract":"Elevated plasma level of lipoprotein(a) (Lp(a)) is a well established risk factor for premature atherosclerosis and coronary artery disease. Recent studies showed impaired endothelium-dependent vasodilatation in humans with elevated plasma Lp(a). However, these human studies could not determine whether (1) elevated Lp(a) levels alone are the cause of endothelial dysfunction (these patients had multiple risk factors), and (2) native or oxidatively modified Lp(a) contributes to endothelial dysfunction (no measurements of native/oxidized Lp(a) ratio was reported in humans). In order to test whether apo(a) (an essential component of Lp(a) which is required for binding to endothelial cells) and native Lp(a) cause endothelial dysfunction, in the present study we tested endothelium-dependent vasorelaxation in aortic rings isolated from control and transgenic male mice either expressing the human apo(a) gene (TgA) or both the human apo(a) and human apo B100 genes (TgL). The TgA mice had plasma apo(a) levels of 8.8 +/- 1.2 mg/dl (n=6) and the double transgenic TgL mice had plasma Lp(a) levels of 15.3 +/- 1.4 mg/dl (n=8). Isolated aortic rings with and without endothelium were mounted in organ chambers and contracted with U46619 (10(-8) M) in the presence of ibuprofen (10(-5) M). Acetylcholine caused concentration-dependent (10(-9)-10(-5) M) relaxation, which could be prevented by endothelium removal and by NG-L-nitro-arginine (10(-4) M). Basal and acetylcholine-stimulated endothelium-dependent relaxation and endothelium-independent relaxation to nitroglycerin (10(-6) M) were not significantly different in aortic rings isolated from control and TgA or TgL mice. Twenty-four hour incubation of aortic rings isolated from control mice with recombinant human apo(a) or native Lp(a) (up to 300 microg/ml) caused no impairment of endothelium-dependent relaxations. In contrast, incubation with oxidized Lp(a) (50 microg/ml) or oxidized LDL (250 microg/ml) caused significant suppression of acetylcholine-induced endothelium-dependent vasorelaxation. These results show for the first time that elevated plasma levels of apo(a) and Lp(a) do not cause endothelial dysfunction in transgenic mice.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"7 1","pages":"253-64"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81941571","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 : 2000-01-01DOI: 10.3109/10623320009072213
A. Chaytor, W. L. Marsh, I. R. Hutcheson, T. Griffith
The vascular actions of the lipophilic gap junction inhibitors 18alpha-glycyrrhetinic acid (18alpha-GA), 18beta-glycyrrhetinic acid (18beta-GA) and the water-soluble hemisuccinate derivative of 18beta-GA, carbenoxolone, were investigated in preconstricted rings of rabbit superior mesenteric artery. EDHF-type relaxations to acetylcholine (ACh), observed in the presence of 300 microM NG-nitro-L-arginine methyl ester (L-NAME) and 10 microM indomethacin, were attenuated by preincubation with 18alpha-GA (to 100 microM), 18A-GA (to 10 microM) or carbenoxolone (to 300 microM) in a concentration-dependent fashion. By contrast, none of these agents affected responses to sodium nitroprusside, an exogeneous source of NO, and relaxations evoked by ACh in the absence of L-NAME were attenuated by only approximately 20%. 18alpha-GA exerted no direct effect on vessel tone, whereas 18beta-GA and carbenoxolone caused relaxations which were maximal at approximately 1 and approximately 10 mM, respectively. Relaxations to carbenoxolone were attenuated by endothelial denudation and by incubation with L-NAME, whereas those to 18beta-GA were unaffected. In conclusion, all three agents inhibit EDHF-type relaxations evoked by ACh, providing further evidence for the involvement of gap junctions in such responses. Unlike 18alpha-GA, carbenoxolone and 18beta-GA possess intrinsic vasorelaxant activity which in the case of carbenoxolone involves functional enhancement of NO activity in addition to direct effects on vascular smooth muscle.
{"title":"Comparison of glycyrrhetinic acid isoforms and carbenoxolone as inhibitors of EDHF-type relaxations mediated via gap junctions.","authors":"A. Chaytor, W. L. Marsh, I. R. Hutcheson, T. Griffith","doi":"10.3109/10623320009072213","DOIUrl":"https://doi.org/10.3109/10623320009072213","url":null,"abstract":"The vascular actions of the lipophilic gap junction inhibitors 18alpha-glycyrrhetinic acid (18alpha-GA), 18beta-glycyrrhetinic acid (18beta-GA) and the water-soluble hemisuccinate derivative of 18beta-GA, carbenoxolone, were investigated in preconstricted rings of rabbit superior mesenteric artery. EDHF-type relaxations to acetylcholine (ACh), observed in the presence of 300 microM NG-nitro-L-arginine methyl ester (L-NAME) and 10 microM indomethacin, were attenuated by preincubation with 18alpha-GA (to 100 microM), 18A-GA (to 10 microM) or carbenoxolone (to 300 microM) in a concentration-dependent fashion. By contrast, none of these agents affected responses to sodium nitroprusside, an exogeneous source of NO, and relaxations evoked by ACh in the absence of L-NAME were attenuated by only approximately 20%. 18alpha-GA exerted no direct effect on vessel tone, whereas 18beta-GA and carbenoxolone caused relaxations which were maximal at approximately 1 and approximately 10 mM, respectively. Relaxations to carbenoxolone were attenuated by endothelial denudation and by incubation with L-NAME, whereas those to 18beta-GA were unaffected. In conclusion, all three agents inhibit EDHF-type relaxations evoked by ACh, providing further evidence for the involvement of gap junctions in such responses. Unlike 18alpha-GA, carbenoxolone and 18beta-GA possess intrinsic vasorelaxant activity which in the case of carbenoxolone involves functional enhancement of NO activity in addition to direct effects on vascular smooth muscle.","PeriodicalId":11588,"journal":{"name":"Endothelium-journal of Endothelial Cell Research","volume":"1 1","pages":"265-78"},"PeriodicalIF":0.0,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90964431","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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