scholarly journals VEGF-A-Cleavage by FSAP and Inhibition of Neo-Vascularization

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1396 ◽  
Author(s):  
Özgür Uslu ◽  
Joerg Herold ◽  
Sandip M. Kanse

Alternative splicing leads to the secretion of multiple forms of vascular endothelial growth factor-A (VEGF-A) that differ in their activity profiles with respect to neovascularization. FSAP (factor VII activating protease) is the zymogen form of a plasma protease that is activated (FSAPa) upon tissue injury via the release of histones. The purpose of the study was to determine if FSAPa regulates VEGF-A activity in vitro and in vivo. FSAP bound to VEGF165, but not VEGF121, and VEGF165 was cleaved in its neuropilin/proteoglycan binding domain. VEGF165 cleavage did not alter its binding to VEGF receptors but diminished its binding to neuropilin. The stimulatory effects of VEGF165 on endothelial cell proliferation, migration, and signal transduction were not altered by FSAP. Similarly, proliferation of VEGF receptor-expressing BAF3 cells, in response to VEGF165, was not modulated by FSAP. In the mouse matrigel model of angiogenesis, FSAP decreased the ability of VEGF165, basic fibroblast growth factor (bFGF), and their combination, to induce neovascularization. Lack of endogenous FSAP in mice did not influence neovascularization. Thus, FSAP inhibited VEGF165-mediated angiogenesis in the matrigel model in vivo, where VEGF’s interaction with the matrix and its diffusion are important.

Blood ◽  
2004 ◽  
Vol 103 (6) ◽  
pp. 2105-2113 ◽  
Author(s):  
Ching-Hu Chung ◽  
Wen-Bin Wu ◽  
Tur-Fu Huang

Abstract Aggretin, a collagen-like α2β1 agonist purified from Calloselasma rhodostoma venom, was shown to increase human umbilical vein endothelial cell (HUVEC) proliferation and HUVEC migration toward immobilized aggretin was also increased. These effects were blocked by A2-IIE10, an antibody raised against integrin α2. Aggretin bound to HUVECs in a dose-dependent and saturable manner, which was specifically inhibited by A2-IIE10, as examined by flow cytometry. Aggretin elicited significant angiogenic effects in both in vivo and in vitro angiogenesis assays, and incubation of HUVECs with aggretin activated phosphatidylinositol 3-kinase (PI3K), Akt, and extracellular-regulated kinase 1/2 (ERK1/2); these effects were blocked by A2-IIE10 or vascular endothelial growth factor (VEGF) monoclonal antibody (mAb). The angiogenic effect induced by aggretin may be via the production of VEGF because the VEGF level was elevated and VEGF mAb pretreatment inhibited Akt/ERK1/2 activation as well as the in vivo angiogenesis induced by aggretin. The VEGF production induced by aggretin can be blocked by A2-IIE10 mAb pretreatment. In conclusion, aggretin induces endothelial cell proliferation, migration, and angiogenesis by interacting with integrin α2β1, leading to activation of PI3K, Akt, and ERK1/2 pathways, and the increased expression of VEGF may be responsible for its angiogenic activity.


2010 ◽  
Vol 298 (3) ◽  
pp. R824-R832 ◽  
Author(s):  
Lucia Morbidelli ◽  
Anastasia Pyriochou ◽  
Sandra Filippi ◽  
Ioannis Vasileiadis ◽  
Charis Roussos ◽  
...  

Nitric oxide (NO) is known to promote vascular endothelial growth factor (VEGF)-stimulated permeability and angiogenesis. However, effector molecules that operate downstream of NO in this pathway remain poorly characterized. Herein, we determined the effect of soluble guanylyl cyclase (sGC) inhibition on VEGF responses in vitro and in vivo. Treatment of endothelial cells (EC) with VEGF stimulated eNOS phosphorylation and cGMP accumulation; pretreatment with the sGC inhibitor 4 H-8-bromo-1,2,4-oxadiazolo(3,4-d)benz(b)(1,4)oxazin-1-one (NS-2028) blunted cGMP levels without affecting VEGF-receptor phosphorylation. Incubation of cells with NS-2028 blocked the mitogenic effects of VEGF. In addition, cells in which sGC was inhibited exhibited no migration and sprouting in response to VEGF. To study the mechanisms through which NS-2028 inhibits EC migration, we determined the effects of alterations in cGMP levels on p38 MAPK. Initially, we observed that inhibition of sGC attenuated VEGF-stimulated activation of p38. In contrast, the addition of 8-Br-cGMP to EC stimulated p38 phosphorylation. The addition of cGMP elevating agents (BAY 41-2272, DETA NO and YC-1) enhanced EC migration. To test whether sGC also mediated the angiogenic effects of VEGF in vivo, we used the rabbit cornea assay. Animals receiving NS-2028 orally displayed a reduced angiogenic response to VEGF. As increased vascular permeability occurs prior to new blood vessel formation, we determined the effect of NS-2028 in vascular leakage. Using a modified Miles assay, we observed that NS-2028 attenuated VEGF-induced permeability. Overall, we provide evidence that sGC mediates the angiogenic and permeability-promoting activities of VEGF, indicating the significance of sGC as a downstream effector of VEGF-triggered responses.


Blood ◽  
2010 ◽  
Vol 116 (11) ◽  
pp. 1980-1989 ◽  
Author(s):  
Monika Edelbauer ◽  
Dipak Datta ◽  
Ingrid H. C. Vos ◽  
Aninda Basu ◽  
Maria P. Stack ◽  
...  

Abstract In these studies, we find that the vascular endothelial growth factor (VEGF) receptor KDR is expressed on subsets of mitogen-activated CD4+ and CD8+ T cells in vitro. We also found that KDR colocalizes with CD3 on mitogen-activated T cells in vitro and on infiltrates within rejecting human allografts in vivo. To evaluate whether VEGF and KDR mediate lymphocyte migration across endothelial cells (ECs), we used an in vitro live-time transmigration model and observed that both anti-VEGF and anti-KDR antibodies inhibit the transmigration of both CD4+ and CD8+ T cells across tumor necrosis factorα (TNFα)–activated, but not unactivated ECs. In addition, we found that interactions among CD4+ or CD8+ T cells and TNFα–activated ECs result in the induction of KDR on each T cell subset, and that KDR-expressing lymphocytes preferentially transmigrate across TNFα–activated ECs. Finally, using a humanized severe combined immunodeficient mouse model of lymphocyte trafficking, we found that KDR-expressing lymphocytes migrate into human skin in vivo, and that migration is reduced in mice treated with a blocking anti-VEGF antibody. These observations demonstrate that induced expression of KDR on subsets of T cells, and locally expressed VEGF, facilitate EC-dependent lymphocyte chemotaxis, and thus, the localization of T cells at sites of inflammation.


2003 ◽  
Vol 55 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Michael D. Mueller ◽  
Elizabeth A. Pritts ◽  
Charles J. Zaloudek ◽  
Ekkehard Dreher ◽  
Robert N. Taylor

Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4150-4166 ◽  
Author(s):  
Dmitry Gabrilovich ◽  
Tadao Ishida ◽  
Tsunehiro Oyama ◽  
Sophia Ran ◽  
Vladimir Kravtsov ◽  
...  

Abstract Defective function of dendritic cells (DC) in cancer has been recently described and may represent one of the mechanisms of tumor evasion from immune system control. We have previously shown in vitro that vascular endothelial growth factor (VEGF), produced by almost all tumors, is one of the tumor-derived factors responsible for the defective function of these cells. In this study, we investigated whether in vivo infusion of recombinant VEGF could reproduce the observed DC dysfunction. Continuous VEGF infusion, at rates as low as 50 ng/h (resulting in serum VEGF concentrations of 120 to 160 pg/mL), resulted in a dramatic inhibition of dendritic cell development, associated with an increase in the production of B cells and immature Gr-1+ myeloid cells. Infusion of VEGF was associated with inhibition of the activity of the transcription factor NF-κB in bone marrow progenitor cells. Experiments in vitro showed that VEGF itself, and not factors released by VEGF-activated endothelial cells, affected polypotent stem cells resulting in the observed abnormal hematopoiesis. These data suggest that VEGF, at pathologically relevant concentrations in vivo, may exert effects on pluripotent stem cells that result in blocked DC development as well as affect many other hematopoietic lineages.


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