scholarly journals VEGF binding to NRP1 is essential for VEGF stimulation of endothelial cell migration, complex formation between NRP1 and VEGFR2, and signaling via FAK Tyr407 phosphorylation

2011 ◽  
Vol 22 (15) ◽  
pp. 2766-2776 ◽  
Author(s):  
Birger Herzog ◽  
Caroline Pellet-Many ◽  
Gary Britton ◽  
Basil Hartzoulakis ◽  
Ian C. Zachary
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Complex Formation ◽  
Rational Design ◽  
Cell Model ◽  
Umbilical Vein ◽  
Focal Adhesions ◽  
Dominant Negative ◽  
Endothelial Cell Migration

In endothelial cells, neuropilin-1 (NRP1) binds vascular endothelial growth factor (VEGF)-A and is thought to act as a coreceptor for kinase insert domain-containing receptor (KDR) by associating with KDR and enhancing VEGF signaling. Here we report mutations in the NRP1 b1 domain (Y297A and D320A), which result in complete loss of VEGF binding. Overexpression of Y297A and D320A NRP1 in human umbilical vein endothelial cells reduced high-affinity VEGF binding and migration toward a VEGF gradient, and markedly inhibited VEGF-induced angiogenesis in a coculture cell model. The Y297A NRP1 mutant also disrupted complexation between NRP1 and KDR and decreased VEGF-dependent phosphorylation of focal adhesion kinase at Tyr407, but had little effect on other signaling pathways. Y297A NRP1, however, heterodimerized with wild-type NRP1 and NRP2 indicating that nonbinding NRP1 mutants can act in a dominant-negative manner through formation of NRP1 dimers with reduced binding affinity for VEGF. These findings indicate that VEGF binding to NRP1 has specific effects on endothelial cell signaling and is important for endothelial cell migration and angiogenesis mediated via complex formation between NRP1 and KDR and increased signaling to focal adhesions. Identification of key residues essential for VEGF binding and biological functions provides the basis for a rational design of antagonists of VEGF binding to NRP1.

scholarly journals CRIF1 deficiency suppresses endothelial cell migration via upregulation of RhoGDI2

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256646
Author(s):  
Harsha Nagar ◽  
Seonhee Kim ◽  
Ikjun Lee ◽  
Su-Jeong Choi ◽  
Shuyu Piao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Signaling Pathway ◽  
Umbilical Vein ◽  
Vascular Endothelial Cell ◽  
Cellular Migration ◽  
Endothelial Cell Migration ◽  
Migration And Invasion ◽  
Mitochondrial Functions

Rho GDP-dissociation inhibitor (RhoGDI), a downregulator of Rho family GTPases, prevents nucleotide exchange and membrane association. It is responsible for the activation of Rho GTPases, which regulate a variety of cellular processes, such as migration. Although RhoGDI2 has been identified as a tumor suppressor gene involved in cellular migration and invasion, little is known about its role in vascular endothelial cell (EC) migration. CR6-interacting factor 1 (CRIF1) is a CR6/GADD45-interacting protein with important mitochondrial functions and regulation of cell growth. We examined the expression of RhoGDI2 in CRIF1-deficient human umbilical vein endothelial cells (HUVECs) and its role in cell migration. Expression of RhoGDI2 was found to be considerably higher in CRIF1-deficient HUVECs along with suppression of cell migration. Moreover, the phosphorylation levels of Akt and CREB were decreased in CRIF1-silenced cells. The Akt-CREB signaling pathway was implicated in the changes in endothelial cell migration caused by CRIF1 downregulation. In addition to RhoGDI2, we identified another factor that promotes migration and invasion of ECs. Adrenomedullin2 (ADM2) is an autocrine/paracrine factor that regulates vascular tone and other vascular functions. Endogenous ADM2 levels were elevated in CRIF1-silenced HUVECs with no effect on cell migration. However, siRNA-mediated depletion of RhoGDI2 or exogenous ADM2 administration significantly restored cell migration via the Akt-CREB signaling pathway. In conclusion, RhoGDI2 and ADM2 play important roles in the migration of CRIF1-deficient endothelial cells.

scholarly journals Autocrine VEGF and IL-8 Promote Migration via Src/Vav2/Rac1/PAK1 Signaling in Human Umbilical Vein Endothelial Cells

2017 ◽  
Vol 41 (4) ◽  
pp. 1346-1359 ◽  
Author(s):  
Li Ju ◽  
Zhiwen Zhou ◽  
Bo Jiang ◽  
Yue Lou ◽  
Xirong Guo
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Endothelial Cell Migration ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Human Umbilical Vein ◽  
Rac1 Activity ◽  
Umbilical Vein Endothelial Cells

Background/Aims: Pro-angiogenic factors VEGF and IL-8 play a major role in modulating the migratory potential of endothelial cells. The goal of this study was to investigate the effect of autocrine VEGF and IL-8 in the form of self-conditioned medium (CM) on human umbilical vein endothelial cells (HUVECs). Methods: Enzyme-linked immunosorbent assay (ELISA) examined the automatic secretion of VEGF and IL-8 protein by HUVECs. Western blot, small interfering RNA (siRNA), pulldown and Transwell assays were used to explore the role and the mechanism of autocrine VEGF and IL-8 in migration of HUVECs. Results: Neutralizing VEGF and IL-8 in CM significantly abrogated CM-induced migration of HUVECs. Autocrine VEGF and IL-8 increased Src phosphorylation, Rac1 activity and PAK1 phosphorylation in a time dependent manner. Additionally, blocking Rac1 activity with Rac1 siRNA largely abolished autocrine VEGF and IL-8-induced cell migration. Vav2 siRNA suppressed autocrine VEGF and IL-8-induced Rac1 activation and cell migration. Furthermore, blocking Src signaling with PP2, a specific inhibitor for Src, markedly prevented autocrine VEGF and IL-8-induced Vav2 and Rac1 activation as well as consequently cell migration. PAK1 siRNA also significantly abolished autocrine VEGF and IL-8-induced cell migration. Conclusions: We demonstrated for the first time that autocrine VEGF and IL-8 promoted endothelial cell migration via the Src/Vav2/Rac1/PAK1 signaling pathway. This finding reveals the molecular mechanism in the increase of endothelial cell migration induced by autocrine growth factors and cytokines, which is expected to provide a novel therapeutic target in vascular diseases.

The histone methyltransferase MLL is an upstream regulator of endothelial-cell sprout formation

Blood ◽  
2006 ◽  
Vol 109 (4) ◽  
pp. 1472-1478 ◽  
Author(s):  
Florian Diehl ◽  
Lothar Rössig ◽  
Andreas M. Zeiher ◽  
Stefanie Dimmeler ◽  
Carmen Urbich
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Underlying Mechanism ◽  
Endothelial Cell Migration ◽  
Cell Functions ◽  
Sprout Formation

Abstract Posttranslational histone modification by acetylation or methylation regulates gene expression. Here, we investigated the role of the histone lysine methyltransferase MLL for angiogenic functions in human umbilical vein endothelial cells. Suppression of MLL expression by siRNA or incubation with the pharmacologic methyltransferase inhibitor 5′-deoxy-5′-(methylthio)adenosine significantly decreased endothelial-cell migration and capillary sprout formation, indicating that methyltransferase activity is required for proangiogenic endothelial-cell functions. Because the expression of homeodomain transcription factors (Hox) is regulated by MLL, we elucidated the role of Hox gene expression. MLL silencing was associated with reduced mRNA and protein expression of HoxA9 and HoxD3, whereas HoxB3, HoxB4, HoxB5, and HoxB9 were not altered. Overexpression of HoxA9 or HoxD3 partially compensated for impaired migration in MLL siRNA-transfected endothelial cells, suggesting that HoxA9 and HoxD3 both contribute to MLL-dependent migration. As a potential underlying mechanism, MLL siRNA down-regulated mRNA and protein levels of the HoxA9-dependent axon guidance factor EphB4. In contrast, MLL knockdown effects on capillary sprouting were not rescued by HoxA9 or HoxD3 overexpression, indicating that MLL affects additional targets required for 3-dimensional sprout formation. We conclude that MLL regulates endothelial-cell migration via HoxA9 and EphB4, whereas sprout formation requires MLL-dependent signals beyond HoxA9 and HoxD3.

Vascular Endothelial Growth Factor (VEGF)-Induced Endothelial Cell Migration Requires Urokinase Receptor (uPAR) for Integrin Redistribution.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 846-846
Author(s):  
Gerald W. Prager ◽  
Johannes M. Breuss4 ◽  
Patrick Brunner4 ◽  
Bernd R. Binder4
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Focal Adhesions ◽  
Specific Inhibitor ◽  
Leading Edge ◽  
Urokinase Receptor ◽  
Endothelial Cell Migration ◽  
Spatial Proximity

Abstract VEGF activates endothelial cells to migrate and invade surrounding tissues, an initial event in the angiogenic process. For invasion, the coordinated localized formation of a proteolytic repertoir is necessary. Focusing the urokinase receptor towards the leading edge of migrating cells provides such armor and inhibition of uPA binding to its receptor inhibits invasion of endothelial cells. In addition integrins continuously have to form focal contacts at the leading edge. Thus the spatial proximity between the localized proteases and the matrix seems to be essential for matrix degradation. In order to allow cell locomotion integrins have to release their ligands when they reach the trailing end and are subsequently endocytosed and redistributed to newly formed focal adhesions in a repetitive process. We here describe a new role of uPAR in regulating integrin redistribution. We have previously reported that stimulation of human endothelial cells by VEGF (50ng/ml) via its receptor flk-1 induces pro-uPA activation, when bound to uPAR. Subsequently a uPA/PAI-1/uPAR-complex is formed, which thereafter is endocytosed via a LDL-R family member. We now show that by this process beta-1 integrins are co-internalized in clathrin coated vesicles via a uPAR dependent mechanism. Subsequently, endocytosed uPAR recycles to focal adhesions where it co-localizes with integrin alpha-v/beta-3. Disrupting this chain of events, either by (1) RAP - a specific inhibitor of the LDL-R family - or by (2) uPAR depletion (using uPAR−/− cells or cleaving the GPI-anchor of uPAR by PI-PLC), beta-1 integrins are no longer internalized after VEGF stimulation. Under the same circumstances the migratory response of endothelial cells toward VEGF is impaired in vitro as shown by video-based migration assays and in vivo as demonstrated by matrigel angiogenesis assays. Next, we generated synthetic peptides interfering with uPAR/integrin interaction, which inhibit not only VEGF-induced integrin redistribution, but also diminish VEGF-induced endothelial cell migration, significantly. These data suggest that in VEGF-induced cell migration uPAR plays a central role not only in focusing proteolytic activity, but also in initial integrin redistribution. Interference with this process could be a therapeutic target for diseases depending on VEGF-induced angiogenesis.

Urokinase-Type Plasminogen Activator Receptor (uPAR, CD87) Regulates Integrin Redistribution in Endothelial Cells Via Interaction with Low Density Lipoprotein Receptor- (LDLR-) Like Proteins

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 5315-5315
Author(s):  
Gerald Prager ◽  
Rene Novotny ◽  
Matthias Unseld ◽  
Marina Poettler ◽  
Waclawa Kalinowska ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Protein Interaction ◽  
Conflicts Of Interest ◽  
Focal Adhesions ◽  
Matrix Proteins ◽  
Endothelial Cell Migration ◽  
Binding Motif ◽  
Wild Type

Abstract Abstract 5315 angiogenesis by degradation of extracellular matrix proteins as well as induction of intracellular signal transduction. We recently could demonstrate that in VEGF-stimulated endothelial cells pro-uPA becomes activated, which leads to uPAR-complex formation, it's internalization and redistribution of uPAR to newly formed focal adhesions ad the leading edge of migrating endothelial cells. Thereby, uPAR surface expression is tightly transcriptional regulated via the Density Enhanced Phosphatase-1 (DEP-1), but also via the LDLR-family members, which regulate subcellular uPAR distribution. Here, we describe a mechanisms by which uPAR-internalization regulates integrin redistribution. We have characterized a novel binding motif on uPAR domain 3 for LDLR-protein interaction by using affinity chromatography as well as co-immunoprecipitation experiments. To proof a functional relevance of a direct uPAR/LDLR protein interaction, we reconstituted either uPAR mutants (mutL3/uPAR), lacking the binding site for LDLR-proteins, or wild type uPAR into endothelial cells derived from uPAR−/− mice. Reconstitution of mutL3/uPAR was incapable to redistribute uPAR as well as integrins during VEGF-induced endothelial cell migration when compared to wild type uPAR reconstitutes. The functional importance of uPAR / LDLR interaction was further reflected by the use of an inhibitory peptide (P1) interfering with uPAR/LDLR-protein interaction, which functionally reverted full length uPAR reconstitution, or the chaperon Receptor Associated Protein (RAP), a high affinity ligand for LDLR-proteins, which prevents uPAR/LDLR interactions. Thus, interfering with uPAR/LDLR-protein interaction at different levels led to an impaired endothelial cell spreading behavior on integrin-adhesive matrix proteins as well as a reduced pY576 FAK phosphorylation upon endothelial cell adhesion, leading to an reduced migratory response towards VEGF. These data suggest a central role of uPAR/LDLR-protein interaction in VEGF-induced endothelial cell migration via induction of integrin redistribution. Thus, uPAR/LDLR interaction might represent a novel therapeutic target in angiogenesis-related diseases. Disclosures: No relevant conflicts of interest to declare.

Microtopography and flow modulate the direction of endothelial cell migration

2008 ◽  
Vol 294 (2) ◽  
pp. H1027-H1035 ◽  
Author(s):  
P. Uttayarat ◽  
M. Chen ◽  
M. Li ◽  
F. D. Allen ◽  
R. J. Composto ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Fluid Shear Stress ◽  
Focal Adhesions ◽  
Endothelial Cell Migration ◽  
High Shear ◽  
High Shear Stress ◽  
Initial Exposure

The migration of vascular endothelial cells under flow can be modulated by the addition of chemical or mechanical stimuli. The aim of this study was to investigate how topographic cues derived from a substrate containing three-dimensional microtopography interact with fluid shear stress in directing endothelial cell migration. Subconfluent bovine aortic endothelial cells were seeded on fibronectin-coated poly(dimethylsiloxane) substrates patterned with a combinatorial array of parallel and orthogonal microgrooves ranging from 2 to 5 μm in width at a constant depth of 1 μm. During a 4-h time-lapse observation in the absence of flow, the majority of the prealigned cells migrated parallel to the grooves with the distribution of their focal adhesions (FAs) depending on the groove width. No change in this migratory pattern was observed after the cells were exposed to moderate shear stress (13.5 dyn/cm2), irrespective of groove direction with respect to flow. After 4-h exposure to high shear stress (58 dyn/cm2) parallel to the grooves, the cells continued to migrate in the direction of both grooves and flow. By contrast, when microgrooves were oriented perpendicular to flow, most cells migrated orthogonal to the grooves and downstream with flow. Despite the change in the migration direction of the cells under high shear stress, most FAs and actin microfilaments maintained their original alignment parallel to the grooves, suggesting that topographic cues were more effective than those derived from shear stress in guiding the orientation of cytoskeletal and adhesion proteins during the initial exposure to flow.

scholarly journals Role of heparan sulfate in mediating CXCL8-induced endothelial cell migration

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1669 ◽  
Author(s):  
Zhiping Yan ◽  
Jingxia Liu ◽  
Linshen Xie ◽  
Xiaoheng Liu ◽  
Ye Zeng
Keyword(s):  
Wound Healing ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Actin Cytoskeleton ◽  
Heparan Sulfate ◽  
Rho Gtpases ◽  
Umbilical Vein ◽  
Endothelial Cell Migration

CXCL8 (Interleukin-8, IL-8) plays an important role in angiogenesis and wound healing by prompting endothelial cell migration. It has been suggested that heparan sulfate (HS) could provide binding sites on endothelial cells to retain and activate highly diffusible cytokines and inflammatory chemokines. In the present study, we aimed to test the hypothesis that HS is essential for enhancement of endothelial cell migration by CXCL8, and to explore the underlying mechanism by detecting the changes in expression and activity of Rho GTPases and in the organization of actin cytoskeleton after enzymatic removal of HS on human umbilical vein endothelial cells (HUVECs) by using heparinase III. Our results revealed that the wound healing induced by CXCL8 was greatly attenuated by removal of HS. The CXCL8-upregulated Rho GTPases including Cdc42, Rac1, and RhoA, and CXCL8-increased Rac1/Rho activity were suppressed by removal of HS. The polymerization and polarization of actin cytoskeleton, and the increasing of stress fibers induced by CXCL8 were also abolished by heparinase III. Taken together, our results demonstrated an essential role of HS in mediating CXCL8-induced endothelial cell migration, and highlighted the biological importance of the interaction between CXCL8 and heparan sulfate in wound healing.

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