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J. Plouet - One of the best experts on this subject based on the ideXlab platform.
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Vasculotropin vascular endothelial growth factor is an autocrine growth factor for human retinal pigment epithelial cells cultured in vitro
Journal of Cellular Physiology, 1995Co-Authors: Marina Guerrin, H. Moukadiri, P. Chollet, Fraņoise Moro, Kamla Dutt, Fraņois Malecaze, J. PlouetAbstract:Vasculotropin (VAS), also called vascular endothelial growth factor (VEGF) or vascular permeability factor, is a secreted growth factor whose target cell specificity has been reported as restricted to vascular endothelium. Its effects are mediated by at least two distinct membrane-spanning tyrosine kinase receptors, KDR and flt-1, the expression of which also seems restricted to vascular endothelium. We describe here that cultured human retinal pigment epithelial (HRPE) cells express both KDR and flt-1 receptors, bind VAS/VEGF on two high affinity sites (apparent Kd of 9 and 210 pM corresponding to 940 and 18,800 sites per cell) and proliferate or migrate upon recombinant VAS/VEGF addition. HRPE cells also express the mRNA corresponding to the 121 and 165 amino acid forms of VAS/VEGF. HRPE cells release in their own culture medium and store in their extracellular matrix self-mitogenic and chemoattractant factors indistinguishable from 121 and 165 VAS/VEGF isoforms. The autocrine role of VAS/VEGF was confirmed by the inhibition of these bioactivities by neutralizing specific anti-VAS/VEGF antibodies. © 1995 Wiley-Liss, Inc.
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Vasculotropin vascular endothelial growth factor induces differentiation in cultured osteoblasts
Biochemical and Biophysical Research Communications, 1994Co-Authors: V Midy, J. PlouetAbstract:Vasculotropin/vascular endothelial growth factor (VAS/VEGF) is an angiogenic growth factor whose biological activity seems to be restricted in vitro to vascular endothelial cells. We describe here that fetal bovine osteoblasts (OB) bind VAS/VEGF but do not proliferate upon its addition. However VAS/VEGF induces migration, PTH-dependent cAMP accumulation and alkaline phosphatase increase when added to OB. The maximal effects reach levels comparable to that obtained with bone morphogenetic protein 2 (BMP-2), although the VAS/VEGF concentrations required are at least 100 fold lower. Our results suggest that VAS/VEGF could be an important regulator of osteoblastic differentiation.
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Vasculotropin-VEGF Stimulates Retinal Capillary Endothelial Cells Through an Autocrine Pathway
Investigative ophthalmology & visual science, 1994Co-Authors: V Simorre-pinatel, M Guerrin, P. Chollet, M Penary, S Clamens, François Malecaze, J. PlouetAbstract:Purpose To determine whether bovine retinal endothelial cells (BRECs) bind, synthesize, and respond to Vasculotropin-vascular endothelial growth factor (VAS-VEGF). Methods Cultured BRECs were tested for their ability to bind 125I VAS-VEGF and their response to the growth and migration-promoting effect of VAS-VEGF. Total RNAs extracted from BRECs were reverse transcribed and amplified by polymerase chain reaction using VAS-VEGF primers. The translation was assessed by a Western blot analysis and a radioreceptor assay in the BREC-conditioned medium. Neutralization with anti-VAS-VEGF antibodies ascertained the autocrine role of VAS-VEGF. Results BRECs bind VAS-VEGF on two high-affinity binding sites (apparent Kd of 2 and 56 pM) and can proliferate and migrate upon the addition of recombinant VAS-VEGF. Furthermore, BRECs synthesize and secrete into their own culture medium a mitogen related to VAS-VEGF as far as two factors are concerned: chromatographic behavior on heparin-affinity columns, and cross-reactivity with recombinant VAS-VEGF to the binding to its receptors or antibodies. Neutralization of the purified conditioned medium with anti-VAS-VEGF antibodies revealed that VAS-VEGF can act on BRECs through an autocrine pathway. Conclusions This is the first description of an autocrine regulation of endothelial cell growth by VAS-VEGF that could be involved in the pathogenesis of retinal neovascularization.
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interaction of Vasculotropin vascular endothelial cell growth factor with human umbilical vein endothelial cells binding internalization degradation and biological effects
Journal of Cellular Physiology, 1991Co-Authors: Andreas Bikfalvi, H. Moukadiri, J. Plouet, C Sauzeau, Jacques Maclouf, N Busso, Marijke Bryckaert, Gerard TobelemAbstract:Vasculotropin/vascular endothelial cell growth factor (VAS/VEGF) is a newly purified growth factor with a unique specificity for vascular endothelial cells. We have investigated the interactions of VAS/VEGF with human umbilical vein endothelial cells (HUVE cells). 125I-VAS/VEGF was found to HUVE cells in a saturable manner with a half-maximum binding at 2.8 ng/ml. Scatchard analysis did show two classes of high-affinity binding sites. The first class displayed a dissociation constant of 9 pM with 500 sites/cell. The dissociation constant and the number of binding sites of the second binding class were variable for different HUVE cell cultures (KD = 179 +/- 101 pM, 5,850 +/- 2,950 sites/cell). Half-maximal inhibition of 125I-VAS/VEGF occurred with a threefold excess of unlabeled ligand. Basic fibroblast growth factor (bFGF) and heparin did not compete with 125I-VAS/VEGF binding. In contrast, suramin and protamin sulfate completely displaced 125I-VAS/VEGF binding from HUVE cells. VAS/VEGF was shown to be internalized in HUVE cells. Maximum internalization (55% of total cell-associated radioactivity) was observed after 30 min. 125I-VAS/VEGF was completely degraded 2-3 hr after binding. At 3 hr, the trichloroacetic acid (TCA)-soluble radioactivity accumulated in the medium was 60% of the total radioactivity released by HUVE cells. No degradation fragment of 125I-VAS/VEGF was observed. Chloroquine completely inhibited degradation. VAS/VEGF was able to induce angiogenesis in vitro in HUVE cells. However, it did not significantly modulate urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), and tissue factor (TF). Prostacyclin production was only stimulated at very high VAS/VEGF concentrations. Taken together, these results indicate that VAS/VEGF might be a potent inducer of neovascularization resulting from a direct interaction with endothelial cells. The angiogenic activity seems to be independent of the plasminogen activator or inhibitor system.
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Vasculotropin: a new angiogenic growth factor
Pathologie-biologie, 1991Co-Authors: H. Moukadiri, C. Favard, Praloran, J. PlouetAbstract:A new growth factor, provisionally named Vasculotropin (VAS), with a unique specificity for vascular endothelial cells has been purified to homogeneity. VAS is a 45 kDa glycosylated homodimeric protein. Cloning of the VAS gene has evidenced a sequence homology with A and B chains of Platelet-Derived Growth Factor. The receptor on vascular endothelial cells has been shown to be a 180 kDa protein. A 110 kDa receptor has been found on cells that do not respond to the mitogenic effect of Vasculotropin, such as lens epithelial cells or corneal endothelial cells.
William E Van Nostrand - One of the best experts on this subject based on the ideXlab platform.
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minocycline reduces microglial activation and improves behavioral deficits in a transgenic model of cerebral microvascular amyloid
The Journal of Neuroscience, 2007Co-Authors: Rong Fan, Judianne Davis, Mary Lou Previti, Alicia M Grande, John K Robinson, William E Van NostrandAbstract:Cerebral microvascular amyloid beta protein (Abeta) deposition and associated neuroinflammation is increasingly recognized as an important component leading to cognitive impairment in Alzheimer's disease and related cerebral amyloid angiopathy disorders. Transgenic mice expressing the vasculotropic Dutch/Iowa (E693Q/D694N) mutant human Abeta precursor protein in brain (Tg-SwDI) accumulate abundant cerebral microvascular fibrillar amyloid deposits and exhibit robust neuroinflammation. In the present study, we investigated the effect of the anti-inflammatory drug minocycline on Abeta accumulation, neuroinflammation, and behavioral deficits in Tg-SwDI mice. Twelve-month-old mice were treated with saline or minocycline by intraperitoneal injection every other day for a total of 4 weeks. During the final week of treatment, the mice were tested for impaired learning and memory. Brains were then harvested for biochemical and immunohistochemical analysis. Minocycline treatment did not alter the cerebral deposition of Abeta or the restriction of fibrillar amyloid to the cerebral microvasculature. Similarly, minocycline-treated Tg-SwDI mice exhibited no change in the levels of total Abeta, the ratios of Abeta40 and Abeta42, or the amounts of soluble, insoluble, or oligomeric Abeta compared with the saline-treated control Tg-SwDI mice. In contrast, the numbers of activated microglia and levels of interleukin-6 were significantly reduced in minocycline-treated Tg-SwDI mice compared with saline-treated Tg-SwDI mice. In addition, there was a significant improvement in behavioral performance of the minocycline-treated Tg-SwDI mice. These finding suggest that anti-inflammatory treatment targeted for cerebral microvascular amyloid-induced microglial activation can improve cognitive deficits without altering the accumulation and distribution of Abeta.
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cerebral microvascular amyloid β protein deposition induces vascular degeneration and neuroinflammation in transgenic mice expressing human vasculotropic mutant amyloid β precursor protein
American Journal of Pathology, 2005Co-Authors: Jianting Miao, Judianne Davis, Irene Otteholler, Marcel M Verbeek, William E Van NostrandAbstract:Cerebral vascular amyloid β-protein (Aβ) deposition, also known as cerebral amyloid angiopathy, is a common pathological feature of Alzheimer's disease. Additionally, several familial forms of cerebral amyloid angiopathy exist including the Dutch (E22Q) and Iowa (D23N) mutations of Aβ. Increasing evidence has associated cerebral microvascular amyloid deposition with neuroinflammation and dementia in these disorders. We recently established a transgenic mouse model (Tg-SwDI) that expresses human vasculotropic Dutch/Iowa mutant amyloid β-protein precursor in brain. Tg-SwDI mice were shown to develop early-onset deposition of Aβ exhibiting high association with cerebral microvessels. Here we present quantitative temporal analysis showing robust and progressive accumulation of cerebral microvascular fibrillar Aβ accompanied by decreased cerebral vascular densities, the presence of apoptotic cerebral vascular cells, and cerebral vascular cell loss in Tg-SwDI mice. Abundant neuroinflammatory reactive astrocytes and activated microglia strongly associated with the cerebral microvascular fibrillar Aβ deposits. In addition, Tg-SwDI mouse brain exhibited elevated levels of the inflammatory cytokines interleukin-1β and −6. Together, these studies identify the Tg-SwDI mouse as a unique model to investigate selective accumulation of cerebral microvascular amyloid and the associated neuroinflammation.
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early onset and robust cerebral microvascular accumulation of amyloid β protein in transgenic mice expressing low levels of a vasculotropic dutch iowa mutant form of amyloid β protein precursor
Journal of Biological Chemistry, 2004Co-Authors: Judianne Davis, Mary Lou Previti, Rashid Deane, Galina Romanov, Kelly Zeigler, Berislav V Zlokovic, William E Van NostrandAbstract:Abstract Cerebrovascular deposition of amyloid β-protein (Aβ) is a common pathological feature of Alzheimer's disease and related disorders. In particular, the Dutch E22Q and Iowa D23N mutations in Aβ cause familial cerebrovascular amyloidosis with abundant diffuse amyloid plaque deposits. Both of these charge-altering mutations enhance the fibrillogenic and pathogenic properties of Aβ in vitro. Here, we describe the generation of several transgenic mouse lines (Tg-SwDI) expressing human neuronal Aβ precursor protein (AβPP) harboring the Swedish K670N/M671L and vasculotropic Dutch/Iowa E693Q/D694N mutations under the control of the mouse Thy1.2 promoter. Tg-SwDI mice expressed transgenic human AβPP only in the brain, but at levels below those of endogenous mouse AβPP. Despite the paucity of human AβPP expression, quantitative enzyme-linked immunosorbent assay measurements revealed that Tg-SwDI mice developed early-onset and robust accumulation of Aβ in the brain with high association with isolated cerebral microvessels. Tg-SwDI mice exhibited striking perivascular/vascular Aβ deposits that markedly increased with age. The vascular Aβ accumulations were fibrillar, exhibiting strong thioflavin S staining, and occasionally presented signs of microhemorrhage. In addition, numerous largely diffuse, plaque-like structures were observed starting at 3 months of age. In vivo transport studies demonstrated that Dutch/Iowa mutant Aβ was more readily retained in the brain compared with wild-type Aβ. These results with Tg-SwDI mice demonstrate that overexpression of human AβPP is not required for early-onset and robust accumulation of both vascular and parenchymal Aβ in mouse brain.
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early onset and robust cerebral microvascular accumulation of amyloid β protein in transgenic mice expressing low levels of a vasculotropic dutch iowa mutant form of amyloid β protein precursor
Journal of Biological Chemistry, 2004Co-Authors: Judianne Davis, Mary Lou Previti, Rashid Deane, Galina Romanov, Kelly Zeigler, Berislav V Zlokovic, William E Van NostrandAbstract:Cerebrovascular deposition of amyloid beta-protein (Abeta) is a common pathological feature of Alzheimer's disease and related disorders. In particular, the Dutch E22Q and Iowa D23N mutations in Abeta cause familial cerebrovascular amyloidosis with abundant diffuse amyloid plaque deposits. Both of these charge-altering mutations enhance the fibrillogenic and pathogenic properties of Abeta in vitro. Here, we describe the generation of several transgenic mouse lines (Tg-SwDI) expressing human neuronal Abeta precursor protein (AbetaPP) harboring the Swedish K670N/M671L and vasculotropic Dutch/Iowa E693Q/D694N mutations under the control of the mouse Thy1.2 promoter. Tg-SwDI mice expressed transgenic human AbetaPP only in the brain, but at levels below those of endogenous mouse AbetaPP. Despite the paucity of human AbetaPP expression, quantitative enzyme-linked immunosorbent assay measurements revealed that Tg-SwDI mice developed early-onset and robust accumulation of Abeta in the brain with high association with isolated cerebral microvessels. Tg-SwDI mice exhibited striking perivascular/vascular Abeta deposits that markedly increased with age. The vascular Abeta accumulations were fibrillar, exhibiting strong thioflavin S staining, and occasionally presented signs of microhemorrhage. In addition, numerous largely diffuse, plaque-like structures were observed starting at 3 months of age. In vivo transport studies demonstrated that Dutch/Iowa mutant Abeta was more readily retained in the brain compared with wild-type Abeta. These results with Tg-SwDI mice demonstrate that overexpression of human AbetaPP is not required for early-onset and robust accumulation of both vascular and parenchymal Abeta in mouse brain.
Judianne Davis - One of the best experts on this subject based on the ideXlab platform.
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minocycline reduces microglial activation and improves behavioral deficits in a transgenic model of cerebral microvascular amyloid
The Journal of Neuroscience, 2007Co-Authors: Rong Fan, Judianne Davis, Mary Lou Previti, Alicia M Grande, John K Robinson, William E Van NostrandAbstract:Cerebral microvascular amyloid beta protein (Abeta) deposition and associated neuroinflammation is increasingly recognized as an important component leading to cognitive impairment in Alzheimer's disease and related cerebral amyloid angiopathy disorders. Transgenic mice expressing the vasculotropic Dutch/Iowa (E693Q/D694N) mutant human Abeta precursor protein in brain (Tg-SwDI) accumulate abundant cerebral microvascular fibrillar amyloid deposits and exhibit robust neuroinflammation. In the present study, we investigated the effect of the anti-inflammatory drug minocycline on Abeta accumulation, neuroinflammation, and behavioral deficits in Tg-SwDI mice. Twelve-month-old mice were treated with saline or minocycline by intraperitoneal injection every other day for a total of 4 weeks. During the final week of treatment, the mice were tested for impaired learning and memory. Brains were then harvested for biochemical and immunohistochemical analysis. Minocycline treatment did not alter the cerebral deposition of Abeta or the restriction of fibrillar amyloid to the cerebral microvasculature. Similarly, minocycline-treated Tg-SwDI mice exhibited no change in the levels of total Abeta, the ratios of Abeta40 and Abeta42, or the amounts of soluble, insoluble, or oligomeric Abeta compared with the saline-treated control Tg-SwDI mice. In contrast, the numbers of activated microglia and levels of interleukin-6 were significantly reduced in minocycline-treated Tg-SwDI mice compared with saline-treated Tg-SwDI mice. In addition, there was a significant improvement in behavioral performance of the minocycline-treated Tg-SwDI mice. These finding suggest that anti-inflammatory treatment targeted for cerebral microvascular amyloid-induced microglial activation can improve cognitive deficits without altering the accumulation and distribution of Abeta.
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cerebral microvascular amyloid β protein deposition induces vascular degeneration and neuroinflammation in transgenic mice expressing human vasculotropic mutant amyloid β precursor protein
American Journal of Pathology, 2005Co-Authors: Jianting Miao, Judianne Davis, Irene Otteholler, Marcel M Verbeek, William E Van NostrandAbstract:Cerebral vascular amyloid β-protein (Aβ) deposition, also known as cerebral amyloid angiopathy, is a common pathological feature of Alzheimer's disease. Additionally, several familial forms of cerebral amyloid angiopathy exist including the Dutch (E22Q) and Iowa (D23N) mutations of Aβ. Increasing evidence has associated cerebral microvascular amyloid deposition with neuroinflammation and dementia in these disorders. We recently established a transgenic mouse model (Tg-SwDI) that expresses human vasculotropic Dutch/Iowa mutant amyloid β-protein precursor in brain. Tg-SwDI mice were shown to develop early-onset deposition of Aβ exhibiting high association with cerebral microvessels. Here we present quantitative temporal analysis showing robust and progressive accumulation of cerebral microvascular fibrillar Aβ accompanied by decreased cerebral vascular densities, the presence of apoptotic cerebral vascular cells, and cerebral vascular cell loss in Tg-SwDI mice. Abundant neuroinflammatory reactive astrocytes and activated microglia strongly associated with the cerebral microvascular fibrillar Aβ deposits. In addition, Tg-SwDI mouse brain exhibited elevated levels of the inflammatory cytokines interleukin-1β and −6. Together, these studies identify the Tg-SwDI mouse as a unique model to investigate selective accumulation of cerebral microvascular amyloid and the associated neuroinflammation.
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early onset and robust cerebral microvascular accumulation of amyloid β protein in transgenic mice expressing low levels of a vasculotropic dutch iowa mutant form of amyloid β protein precursor
Journal of Biological Chemistry, 2004Co-Authors: Judianne Davis, Mary Lou Previti, Rashid Deane, Galina Romanov, Kelly Zeigler, Berislav V Zlokovic, William E Van NostrandAbstract:Abstract Cerebrovascular deposition of amyloid β-protein (Aβ) is a common pathological feature of Alzheimer's disease and related disorders. In particular, the Dutch E22Q and Iowa D23N mutations in Aβ cause familial cerebrovascular amyloidosis with abundant diffuse amyloid plaque deposits. Both of these charge-altering mutations enhance the fibrillogenic and pathogenic properties of Aβ in vitro. Here, we describe the generation of several transgenic mouse lines (Tg-SwDI) expressing human neuronal Aβ precursor protein (AβPP) harboring the Swedish K670N/M671L and vasculotropic Dutch/Iowa E693Q/D694N mutations under the control of the mouse Thy1.2 promoter. Tg-SwDI mice expressed transgenic human AβPP only in the brain, but at levels below those of endogenous mouse AβPP. Despite the paucity of human AβPP expression, quantitative enzyme-linked immunosorbent assay measurements revealed that Tg-SwDI mice developed early-onset and robust accumulation of Aβ in the brain with high association with isolated cerebral microvessels. Tg-SwDI mice exhibited striking perivascular/vascular Aβ deposits that markedly increased with age. The vascular Aβ accumulations were fibrillar, exhibiting strong thioflavin S staining, and occasionally presented signs of microhemorrhage. In addition, numerous largely diffuse, plaque-like structures were observed starting at 3 months of age. In vivo transport studies demonstrated that Dutch/Iowa mutant Aβ was more readily retained in the brain compared with wild-type Aβ. These results with Tg-SwDI mice demonstrate that overexpression of human AβPP is not required for early-onset and robust accumulation of both vascular and parenchymal Aβ in mouse brain.
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early onset and robust cerebral microvascular accumulation of amyloid β protein in transgenic mice expressing low levels of a vasculotropic dutch iowa mutant form of amyloid β protein precursor
Journal of Biological Chemistry, 2004Co-Authors: Judianne Davis, Mary Lou Previti, Rashid Deane, Galina Romanov, Kelly Zeigler, Berislav V Zlokovic, William E Van NostrandAbstract:Cerebrovascular deposition of amyloid beta-protein (Abeta) is a common pathological feature of Alzheimer's disease and related disorders. In particular, the Dutch E22Q and Iowa D23N mutations in Abeta cause familial cerebrovascular amyloidosis with abundant diffuse amyloid plaque deposits. Both of these charge-altering mutations enhance the fibrillogenic and pathogenic properties of Abeta in vitro. Here, we describe the generation of several transgenic mouse lines (Tg-SwDI) expressing human neuronal Abeta precursor protein (AbetaPP) harboring the Swedish K670N/M671L and vasculotropic Dutch/Iowa E693Q/D694N mutations under the control of the mouse Thy1.2 promoter. Tg-SwDI mice expressed transgenic human AbetaPP only in the brain, but at levels below those of endogenous mouse AbetaPP. Despite the paucity of human AbetaPP expression, quantitative enzyme-linked immunosorbent assay measurements revealed that Tg-SwDI mice developed early-onset and robust accumulation of Abeta in the brain with high association with isolated cerebral microvessels. Tg-SwDI mice exhibited striking perivascular/vascular Abeta deposits that markedly increased with age. The vascular Abeta accumulations were fibrillar, exhibiting strong thioflavin S staining, and occasionally presented signs of microhemorrhage. In addition, numerous largely diffuse, plaque-like structures were observed starting at 3 months of age. In vivo transport studies demonstrated that Dutch/Iowa mutant Abeta was more readily retained in the brain compared with wild-type Abeta. These results with Tg-SwDI mice demonstrate that overexpression of human AbetaPP is not required for early-onset and robust accumulation of both vascular and parenchymal Abeta in mouse brain.
H. Moukadiri - One of the best experts on this subject based on the ideXlab platform.
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Vasculotropin vascular endothelial growth factor is an autocrine growth factor for human retinal pigment epithelial cells cultured in vitro
Journal of Cellular Physiology, 1995Co-Authors: Marina Guerrin, H. Moukadiri, P. Chollet, Fraņoise Moro, Kamla Dutt, Fraņois Malecaze, J. PlouetAbstract:Vasculotropin (VAS), also called vascular endothelial growth factor (VEGF) or vascular permeability factor, is a secreted growth factor whose target cell specificity has been reported as restricted to vascular endothelium. Its effects are mediated by at least two distinct membrane-spanning tyrosine kinase receptors, KDR and flt-1, the expression of which also seems restricted to vascular endothelium. We describe here that cultured human retinal pigment epithelial (HRPE) cells express both KDR and flt-1 receptors, bind VAS/VEGF on two high affinity sites (apparent Kd of 9 and 210 pM corresponding to 940 and 18,800 sites per cell) and proliferate or migrate upon recombinant VAS/VEGF addition. HRPE cells also express the mRNA corresponding to the 121 and 165 amino acid forms of VAS/VEGF. HRPE cells release in their own culture medium and store in their extracellular matrix self-mitogenic and chemoattractant factors indistinguishable from 121 and 165 VAS/VEGF isoforms. The autocrine role of VAS/VEGF was confirmed by the inhibition of these bioactivities by neutralizing specific anti-VAS/VEGF antibodies. © 1995 Wiley-Liss, Inc.
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interaction of Vasculotropin vascular endothelial cell growth factor with human umbilical vein endothelial cells binding internalization degradation and biological effects
Journal of Cellular Physiology, 1991Co-Authors: Andreas Bikfalvi, H. Moukadiri, J. Plouet, C Sauzeau, Jacques Maclouf, N Busso, Marijke Bryckaert, Gerard TobelemAbstract:Vasculotropin/vascular endothelial cell growth factor (VAS/VEGF) is a newly purified growth factor with a unique specificity for vascular endothelial cells. We have investigated the interactions of VAS/VEGF with human umbilical vein endothelial cells (HUVE cells). 125I-VAS/VEGF was found to HUVE cells in a saturable manner with a half-maximum binding at 2.8 ng/ml. Scatchard analysis did show two classes of high-affinity binding sites. The first class displayed a dissociation constant of 9 pM with 500 sites/cell. The dissociation constant and the number of binding sites of the second binding class were variable for different HUVE cell cultures (KD = 179 +/- 101 pM, 5,850 +/- 2,950 sites/cell). Half-maximal inhibition of 125I-VAS/VEGF occurred with a threefold excess of unlabeled ligand. Basic fibroblast growth factor (bFGF) and heparin did not compete with 125I-VAS/VEGF binding. In contrast, suramin and protamin sulfate completely displaced 125I-VAS/VEGF binding from HUVE cells. VAS/VEGF was shown to be internalized in HUVE cells. Maximum internalization (55% of total cell-associated radioactivity) was observed after 30 min. 125I-VAS/VEGF was completely degraded 2-3 hr after binding. At 3 hr, the trichloroacetic acid (TCA)-soluble radioactivity accumulated in the medium was 60% of the total radioactivity released by HUVE cells. No degradation fragment of 125I-VAS/VEGF was observed. Chloroquine completely inhibited degradation. VAS/VEGF was able to induce angiogenesis in vitro in HUVE cells. However, it did not significantly modulate urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), and tissue factor (TF). Prostacyclin production was only stimulated at very high VAS/VEGF concentrations. Taken together, these results indicate that VAS/VEGF might be a potent inducer of neovascularization resulting from a direct interaction with endothelial cells. The angiogenic activity seems to be independent of the plasminogen activator or inhibitor system.
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Vasculotropin: a new angiogenic growth factor
Pathologie-biologie, 1991Co-Authors: H. Moukadiri, C. Favard, Praloran, J. PlouetAbstract:A new growth factor, provisionally named Vasculotropin (VAS), with a unique specificity for vascular endothelial cells has been purified to homogeneity. VAS is a 45 kDa glycosylated homodimeric protein. Cloning of the VAS gene has evidenced a sequence homology with A and B chains of Platelet-Derived Growth Factor. The receptor on vascular endothelial cells has been shown to be a 180 kDa protein. A 110 kDa receptor has been found on cells that do not respond to the mitogenic effect of Vasculotropin, such as lens epithelial cells or corneal endothelial cells.
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Purification and biological properties of Vasculotropin, a new angiogenic cytokine
Biology of the cell, 1991Co-Authors: C. Favard, H. Moukadiri, Christiane Dorey, Vincent Praloran, J. PlouetAbstract:Anglogenesis is a key step in organ development and remodeling during embryogenesis or tissue regeneration. Some pathological events such as tumor growth or diabetic retinopathy also lead to angiogenesis formation. Several molecules have already been identified as promoting anglogenesis in vivo. Whether their bioactivity is mediated by other angiogenic growth factors or not is still unclear. We identified and purified recently a new anglogenic growth factor. Its unique specificity for vascular endothelial cells led us to provisionally name it Vasculotropin (VAS). We describe the biochemical properties of VAS and its biological functions. Structural data showed that VAS is related to the SIS family. In vivo VAS was recognized as an inducer of angiogenesis and vascular permeability. In vitro, despite a moderate action on proliferation, VAS strongly stimulates the cell migration. The screening of the presence of cellular receptors and VAS production showed that the cells which bind VAS do not synthesize it, whereas the cells which synthesize VAS do not bind it. Thus, VAS seems to act through a paracrine pathway. We also present data suggesting that VAS has a lymphokine activity.
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Mitogenic activity of Vasculotropin for peripheral human lymphocytes
Comptes rendus de l'Academie des sciences. Serie III Sciences de la vie, 1991Co-Authors: Praloran, H. Moukadiri, C. Favard, S. Mirshahi, J. PlouetAbstract:Vasculotropin is a growth factor with a unique specificity for vascular derived endothelial cells. We report that normal human peripheral lymphocytes represent another target for Vasculotropin. The mitogenic activity of the medium conditioned by these cells cultured in the presence of Concanavalin A is potentiated by Vasculotropin. This effect is exerted more likely through interactions with the soluble mediators rather than through the VAS receptors since VAS binds equally to Concanavalin A stimulated and to unstimulated lymphocytes.
Roberto Montesano - One of the best experts on this subject based on the ideXlab platform.
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potent synergism between vascular endothelial growth factor and basic fibroblast growth factor in the induction of angiogenesis in vitro
Biochemical and Biophysical Research Communications, 1992Co-Authors: Michael S Pepper, Napoleone Ferrara, L Orci, Roberto MontesanoAbstract:Abstract Vascular endothelial growth factor (VEGF), also known as vascular permeability factor or Vasculotropin, is a recently characterized endothelial-specific mitogen which is angiogenic in vivo. Here we demonstrate that VEGF is angiogenic in vitro: when added to microvascular endothelial cells grown on the surface of three-dimensional collagen gels, VEGF induces the cells to invade the underlying matrix and to form capillary-like tubules, with an optimal effect at approximately 2.2nM (100ng/ml). When compared to basic fibroblast growth factor (bFGF) at equimolar (0.5nM) concentrations, VEGF was about half as potent. The most striking effect was seen in combination with bFGF: when added simultaneously, VEGF and bFGF indubFGF induced an in vitro angiogenic response which was far greater than additive, and which occurred with greater rapidity than the response to either cytokine alone. These results demonstrate that like bFGF, VEGF induces an angiogenic response via a direct effect on endothelial cells, and that by acting in concert, these two cytokines have a potent synergistic effect on the induction of angiogenesis in vitro. We suggest that the synergism between VEGF and bFGF plays an important role in the control of angiogenesis in vivo.
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Potent synergism between vascular endothelial growth factor and basic fibroblast growth factor in the induction of angiogenesis in vitro
Biochemical and biophysical research communications, 1992Co-Authors: Michael S Pepper, Napoleone Ferrara, L Orci, Roberto MontesanoAbstract:Vascular endothelial growth factor (VEGF), also known as vascular permeability factor or Vasculotropin, is a recently characterized endothelial-specific mitogen which is angiogenic in vivo. Here we demonstrate that VEGF is angiogenic in vitro: when added to microvascular endothelial cells grown on the surface of three-dimensional collagen gels, VEGF induces the cells to invade the underlying matrix and to form capillary-like tubules, with an optimal effect at approximately 2.2nM (100ng/ml). When compared to basic fibroblast growth factor (bFGF) at equimolar (0.5nM) concentrations, VEGF was about half as potent. The most striking effect was seen in combination with bFGF: when added simultaneously, VEGF and bFGF induced an in vitro angiogenic response which was far greater than additive, and which occurred with greater rapidity than the response to either cytokine alone. These results demonstrate that like bFGF, VEGF induces an angiogenic response via a direct effect on endothelial cells, and that by acting in concert, these two cytokines have a potent synergistic effect on the induction of angiogenesis in vitro. We suggest that the synergism between VEGF and bFGF plays an important role in the control of angiogenesis in vivo.