X-Linked Inhibitor of Apoptosis Protein (XIAP) Supports Urokinase (uPA)-Induced Endothelial Cell Survival

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5461-5461
Author(s):  
Gerald W Prager ◽  
Judit Mihaly ◽  
Patrick Brunner ◽  
Christoph Zielinski ◽  
Bernd Binder
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Cell Survival ◽  
Endothelial Cell Migration ◽  
Migration And Invasion ◽  
Inhibitor Of Apoptosis ◽  
Inhibitor Of Apoptosis Protein ◽  
Endothelial Cell Survival ◽  
Apoptosis Protein

Abstract High uPA expressing tumors are associated with poor prognosis. While a direct effect on tumor cell behavior is described, uPA has especially been shown to mediate (tumor-) angiogenesis. Originally, the urokinase system has been implicated to assist the angiogenic process by it’s proteolytic activities. It is now becoming increasingly evident that uPA additionally elicits a whole array pro-angiogenic responses like differentiation, proliferation and cell migration, independent of its proteolytic activity by inducing intracellular signal transduction. Here we show that uPA induces upregulation of inhibitor of apoptosis proteins (IAPs), which protects endothelial cells against apoptosis. Thereby, uPA-induced endothelial cell survival is mediated by transcriptional upregulation the X-linked inhibitor of apoptosis protein (XIAP), because downregulation of XIAP by small interfering RNA techniques significantly reduces uPA mediated cell survival efficiencies of uPA in endothelial cells. The antiapoptotic activity of uPA was dependent on the presence of uPAR and LRP, but independent of the PI3kinase pathway, while VEGF-dependent antiapoptosis is mainly PI3kinase dependent. uPA-induced cell survival is dependent on the type of extracellular matrix on which cells are attached used indicating the involvement of integrin adhesion receptors. TherebyConsistently, uPA induces phosphorylation of the CDC42 downstream effector p21-activated kinase 1 (PAK1), which leads to IkappaB kinase alpha (IKKa) phosphorylation, a prerequisite for NFkappaB activation. As a consequence, p52/p50 but not p65 is are translocated into the nucleus. Blocking NFkappaB by using the specific NFkappaB inhibitor BAY 11–7082 or by adenoviral-mediated overexpression of its inhibitor, IkB, inhibits uPA-induced XIAP expression as well as uPA-induced cell survival. From these data we conclude that uPA, which is a main player in endothelial cell migration and invasion, provides an additional, PI3-kinase independent but NFkappaB dependent cell survival mechanism.

Urokinase (uPA) Induces Endothelial Cell Survival Via the X-Linked Inhibitor of Apoptosis Protein (XIAP).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3712-3712
Author(s):  
Gerald W. Prager ◽  
Patrick M. Brunner ◽  
Judit Mihaly ◽  
Yuri Koschelnick ◽  
Bernd R. Binder
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Cell Survival ◽  
Pi3 Kinase ◽  
Endothelial Cell Migration ◽  
Inhibitor Of Apoptosis ◽  
Inhibitor Of Apoptosis Protein ◽  
Xiap Expression ◽  
Apoptosis Protein

Abstract uPA plays an important role in angiogenesis: Originally, the urokinase system has been implicated to assist the angiogenic process by it’s proteolytic properties. It is now becoming increasingly evident that uPA additionally elicits many pro-angiogenic responses like differentiation, proliferation and cell migration in a non-proteolytic fashion via induction of intracellular signal transduction. In this study we demonstrate that in endothelial cells uPA protects against apoptosis by transcriptional upregulation of inhibitor of apoptosis proteins (IAPs), among them most prominently the X-linked inhibitor of apoptosis protein (XIAP). In contrast to canonical growth factors, like vascular endothelial growth factor (VEGF), uPA elicits anti-apoptosis independently of the PI3-kinase pathway. uPA-induced cell survival is dependent on the type of extracellular matrix used indicating the involvement of integrin adhesion receptors. Thereby, uPA induces phosphorylation of the CDC42 downstream effector p21-activated kinase 1 (PAK1), which leads to IkappaB kinase alpha (IKKa) phosphorylation, a prerequisite for NFkappaB activation. Blocking NFkappaB by using the specific NFkappaB inhibitor BAY 11–7082 or by adenoviral-mediated overexpression of its inhibitor, IkB, inhibits uPA-induced XIAP expression as well as uPA-induced cell survival. Downregulating XIAP expression by small interfering RNA techniques significantly reduces cell survival efficiencies of uPA in endothelial cells. From these data we conclude that uPA activation, which is a main player in endothelial cell migration and invasion, provides an additional, PI3-kinase independent cell survival mechanism.

Urokinase mediates endothelial cell survival via induction of the X-linked inhibitor of apoptosis protein

Blood ◽  
2009 ◽  
Vol 113 (6) ◽  
pp. 1383-1390 ◽  
Author(s):  
Gerald W. Prager ◽  
Judit Mihaly ◽  
Patrick M. Brunner ◽  
Yuri Koshelnick ◽  
Gunilla Hoyer-Hansen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Survival ◽  
Pi3 Kinase ◽  
Inhibitor Of Apoptosis ◽  
Inhibitor Of Apoptosis Protein ◽  
Mrna Stabilization ◽  
Endothelial Cell Survival ◽  
Iκb Kinase ◽  
Apoptosis Protein

AbstractUrokinase-type plasminogen activator (uPA) additionally elicits a whole array of pro-angiogenic responses, such as differentiation, proliferation, and migration. In this study, we demonstrate that in endothelial cells uPA also protects against apoptosis by transcriptional up-regulation and partially by mRNA stabilization of inhibitor of apoptosis proteins, most prominently the X-linked inhibitor of apoptosis protein (XIAP). The antiapoptotic activity of uPA was dependent on its protease activity, the presence of uPA receptor (uPAR) and low-density lipoprotein receptor-related protein (LRP), but independent of the phosphatidylinositol 3 (PI3) kinase pathway, whereas vascular endothelial growth factor (VEGF)–induced antiapoptosis was PI3 kinase dependent. uPA-induced cell survival involved phosphorylation of p21-activated kinase 1 (Pak1) and the IκB kinase α that leads to nuclear factor κB (NF-κB) p52 activation. Indeed, blocking NF-κB activation by using specific NF-κB inhibitors abolished uPA-induced cell survival as it blocked uPA-induced XIAP up-regulation. Furthermore, down-regulating XIAP expression by small interfering RNA (siRNA) significantly reduced uPA-dependent endothelial cell survival. This mechanism is also important for VEGF-induced antiapoptosis because VEGF-dependent up-regulation of XIAP was found defective in uPA−/− endothelial cells. This led us to conclude that uPA is part of a novel NF-κB–dependent cell survival pathway.

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.

Neuropilin-2 interacts with VEGFR-2 and VEGFR-3 and promotes human endothelial cell survival and migration

Blood ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 1243-1250 ◽  
Author(s):  
Benoit Favier ◽  
Antoine Alam ◽  
Pauline Barron ◽  
Jacques Bonnin ◽  
Patricia Laboudie ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Survival ◽  
Endothelial Cell Migration ◽  
Human Endothelial Cell ◽  
Human Endothelial Cells ◽  
Endothelial Cell Survival ◽  
Biological Responses ◽  
And Migration ◽  
Endothelial Growth Factor

Abstract Neuropilin 2 (NRP2) is a receptor for the vascular endothelial growth factor (VEGF) and the semaphorin (SEMA) families, 2 unrelated ligand families involved in angiogenesis and neuronal guidance. NRP2 specifically binds VEGF-A and VEGF-C, although the biological relevance of these interactions in human endothelial cells is poorly understood. In this study, we show that both VEGF-A and VEGF-C induce the interaction of NRP2 with VEGFR-2. This interaction correlated with an enhancement of the VEGFR-2 phosphorylation threshold. Overexpression of NRP2 in primary human endothelial cells promoted cell survival induced by VEGF-A and VEGF-C. In contrast, SEMA3F, another ligand for NRP2, was able to inhibit human endothelial cell survival and migration induced by VEGF-A and VEGF-C. Moreover, a siRNA targeting specifically NRP2 was a potent inhibitor of human endothelial cell migration induced by VEGF-A and VEGF-C. Thus, our data indicate that NRP2 acts as a coreceptor that enhances human endothelial cell biological responses induced by VEGF-A and VEGF-C.

scholarly journals Density enhanced phosphatase-1 down-regulates urokinase receptor surface expression in confluent endothelial cells

Blood ◽  
2011 ◽  
Vol 117 (15) ◽  
pp. 4154-4161 ◽  
Author(s):  
Patrick M. Brunner ◽  
Patricia C. Heier ◽  
Judit Mihaly-Bison ◽  
Ute Priglinger ◽  
Bernd R. Binder ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Endothelial Cell Migration ◽  
Cell Surface Receptor ◽  
Migration And Invasion ◽  
Cell Behavior ◽  
Vegf Receptor ◽  
Receptor System ◽  
Upar Expression

Abstract VEGF165, the major angiogenic growth factor, is known to activate various steps in proangiogenic endothelial cell behavior, such as endothelial cell migration and invasion, or endothelial cell survival. Thereby, the urokinase-type plasminogen activator (uPA) system has been shown to play an essential role not only by its proteolytic capacities, but also by induction of intracellular signal transduction. Therefore, expression of its cell surface receptor uPAR is thought to be an essential regulatory mechanism in angiogenesis. We found that uPAR expression on the surface of confluent endothelial cells was down-regulated compared with subconfluent proliferating endothelial cells. Regulation of uPAR expression was most probably affected by extracellular signal-regulated kinase 1/2 (ERK1/2) activation, a downstream signaling event of the VEGF/VEGF-receptor system. Consistently, the receptor-like protein tyrosine phosphatase DEP-1 (density enhanced phosphatase-1/CD148), which is abundantly expressed in confluent endothelial cells, inhibited the VEGF-dependent activation of ERK1/2, leading to down-regulation of uPAR expression. Overexpression of active ERK1 rescued the DEP-1 effect on uPAR. That DEP-1 plays a biologic role in angiogenic endothelial cell behavior was demonstrated in endothelial cell migration, proliferation, and capillary-like tube formation assays in vitro.

Signaling and regulation of endothelial cell survival by angiopoietin-2

2006 ◽  
Vol 291 (4) ◽  
pp. H1635-H1645 ◽  
Author(s):  
Rania Harfouche ◽  
Sabah N. A. Hussain
Keyword(s):  
Cell Migration ◽  
Endothelial Cell ◽  
Cell Survival ◽  
Umbilical Vein ◽  
Biological Effects ◽  
Pi3 Kinase ◽  
Endothelial Cell Migration ◽  
Endothelial Cell Survival ◽  
Induced Apoptosis

Angiopoietins are ligands for endothelial cell-specific Tie-2 receptors. Whereas angiopoietin-1 (Ang-1) activates these receptors and promotes cell survival, migration, and sprouting, little information is available regarding how Ang-2 influences these cells. In this study, we evaluated signaling pathways and biological effects of physiological concentrations of Ang-2 in cultured human umbilical vein endothelial cells. Ang-2 at 150 and 300 ng/ml elicited a transient (reaching peak values within 15 min of exposure) increase in the phosphorylation of Tie-2 receptors, protein kinase B (Akt), ERK1/2, and p38 members of the mitogen-activated protein kinases. However, unlike Ang-1, Ang-2 significantly inhibited JNK/SAPK phosphorylation. When vascular endothelial growth factor (VEGF) was present along with Ang-2, ERK1/2 phosphorylation was inhibited, whereas augmentation of Ang-1-induced ERK1/2 phosphorylation was triggered by VEGF. Ang-2 treatment had no effect on cell migration and in vitro wound healing but significantly attenuated serum deprivation-induced apoptosis and promoted survival. These effects were completely reversed by phosphatidylinositol 3 (PI3)-kinase and ERK1/2 inhibitors but were augmented by an inhibitor of the p38 pathway. These results suggest that Ang-2 promotes endothelial cell survival through the ERK1/2 and PI3-kinase pathways and that this angiopoietin is not a strong promoter of endothelial cell migration. We also conclude that the nature of interactions in terms of ERK1/2 activation between Ang-2 and VEGF is different from that of Ang-1 and VEGF.

Vascular Endothelial Growth Factor (VEGF) Induces Cell Survival Via an Additional Urokinase (uPA)-Dependent Mechanism.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3919-3919
Author(s):  
Gerald W. Prager ◽  
Yuri Koshelnick ◽  
Judit Mihaly ◽  
Patrick Brunner ◽  
Bernd R. Binder
Keyword(s):  
Endothelial Cell ◽  
Growth Factor ◽  
Cell Survival ◽  
Pi3 Kinase ◽  
Endothelial Cell Migration ◽  
Inhibitor Of Apoptosis ◽  
Dependent Manner ◽  
Independent Manner ◽  
Apoptosis Protein ◽  
Nf Kappab

Abstract VEGF, the most important angiogenic growth factor, is known to induce cell-survival mainly via phosphorylation of the pro-apoptotic proteins BAD, PED/PEA-2 or pro-caspase-9 or inhibition of SAPKs (stress activated kinases). These mechanisms are all dependent on the PI3-kinase/Akt pathway. We could show recently that VEGF also induces pro-uPA activation via the PI3-kinase signaling pathway beside and independent of the transcriptional upregulation of uPA. Active uPA does not only contribute to angiogenesis via its proteolytic properties, but also effectuates itself pro-angiogenic signalling by the induction of endothelial cell migration, proliferation and differentiation. We were interested whether generation of uPA upon VEGF is inducing an additional effect on endothelial cell survival. First, we compared VEGF with urokinase in respect to cell survival in apoptosis assays and observed a pivotal anti-apoptotic effect of both stimuli, dose dependently and dependent on the type of matrix used. In addition, cell survival effects were additive, when both stimuli were added simultaneously. While VEGF-induced cell survival was PI3-kinase dependent, because it could be inhibited by the specific PI3-kinase inhibitor LY294002, the uPA-induced cell survival was PI3-kinase independent. Furthermore, uPA was able to rescue apoptosis induced by PI3-kinase inhibition in VEGF stimulated endothelial cells. From these data we conclude that uPA is indeed inducing an additional - PI3-kinase independent - cell survival mechanism. While VEGF led to a PI3-kinase dependent phosphorylation of Akt, which resulted in CDC42 activation, uPA activated CDC42 and its downstream effectors PAK leading to IKK-1 phosphorylation in a PI3-kinase/Akt independent manner. This indicates that the anti-apoptotic properties of uPA are not Akt, but NF-kappaB mediated. Indeed, when we used adenovirus overexpressing I-kappaB to block the NF-kappaB pathway, uPA was ineffective to support cell survival. In addition VEGF and uPA, both induced a transcriptional upregulation of inhibitor of apoptosis proteins (IAPs) in an NF-kappaB-dependent manner, among them most significantly the X-linked inhibitor of apoptosis protein (XIAP); again VEGF in a PI3-kinase dependent, uPA in a PI3-kinase independent manner. From these data we conclude that VEGF is inducing cell survival in a strictly PI3-kinase dependent manner, on the one hand via its known mitochondrial pathway, but also via the PI3-kinase dependent pro-uPA activation leading to an NFkappa B dependent upregulation of inhibitor of antiapoptosis proteins.

scholarly journals Lysophospholipids Enhance Matrix Metalloproteinase-2 Expression in Human Endothelial Cells

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3387-3400 ◽  
Author(s):  
Wen Ting Wu ◽  
Chiung-Nien Chen ◽  
Chi Iou Lin ◽  
Jiun Hong Chen ◽  
Hsinyu Lee
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Cell Invasion ◽  
Proteolytic Enzymes ◽  
Endothelial Cell Migration ◽  
Matrix Metalloproteinase 2 ◽  
Migration And Invasion ◽  
Human Endothelial Cells ◽  
Western Blots

Abstract Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are both low-molecular-weight lysophospholipids, which promote cell proliferation, migration, and invasion via interaction with a family of specific G protein-coupled receptors. Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic enzymes, which are involved in degradation of the extracellular matrix and play critical roles in endothelial cell migration and matrix remodeling during angiogenesis. Among these MMPs, MMP-2 is known to trigger cell migration. In our present study, we examined the effects of LPA and S1P on MMP-2 expression in human endothelial cells. We showed that LPA and S1P enhanced MMP-2 expression in mRNA, protein levels, and also enzymatic activity of cells of the EAhy926 human endothelial cell line. The enhancement effects occurred in concentration- and time-dependent manners. Results from real-time PCR, Western blots, and substrate gels indicated that these enhancement effects were mediated through MAPK kinase/ERK-, nuclear factor-κB-, and calcium influx-dependent pathways. Furthermore, we show that endothelial cell invasion of the gel was enhanced by lysophospholipids, and the induction could be prevented by an MMP inhibitor, GM6001. These observations suggest that LPA and S1P may play important roles in endothelial cell invasion by regulating the expression of MMP-2.

Examining the relationship between the gelatinolytic balance and the invasive capacity of endothelial cells

1999 ◽  
Vol 112 (9) ◽  
pp. 1283-1290 ◽  
Author(s):  
A. Puyraimond ◽  
J.B. Weitzman ◽  
E. Babiole ◽  
S. Menashi
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Synergistic Effect ◽  
Cell Motility ◽  
Endothelial Cell Migration ◽  
Migration And Invasion ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Invasive Capacity

Angiogenesis and the formation of new blood vessels requires coordinated regulation of matrix proteolysis and endothelial cell migration. Cellular proteolytic capacity is the balance between secreted matrix metalloproteinases (MMP) and their inhibitors (TIMPs). We have examined the regulation of the gelatinase/TIMP balance by transforming growth factor-beta1 (TGF-beta1) and phorbol myristate acetate (PMA) in bovine endothelial cells. The low constitutive expression of gelatinase A/MMP-2 was upregulated by TGF-beta1 in a dose-dependent manner. Gelatinase B/MMP-9 was only detected upon treatment with either PMA or TGF-beta1. However, addition of both factors together revealed a striking synergistic effect causing upregulation of MMP-9 and downregulation of TIMPs, thereby increasing the net MMP-9/TIMP balance and the gelatinolytic capacity. These effects were observed at both the protein and mRNA levels. We demonstrate that changes in different members of the Jun oncogene family with distinct transactivation properties may account for this synergistic effect. We investigated the contribution of these changes in gelatinolytic balance to endothelial cell migration and invasion. The endothelial cells showed increased cell motility in response to PMA, but the addition of TGF-beta1 had an inhibitory effect. Hence, regulation of the MMP-9/TIMP balance failed to correlate with the migratory or invasive capacity. These results question a direct role for MMP-9 in endothelial cell motility and suggest that gelatinases may contribute in alternative ways to the angiogenic process.

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