scholarly journals PTP-ε, a tyrosine phosphatase expressed in endothelium, negatively regulates endothelial cell proliferation

2001 ◽  
Vol 281 (1) ◽  
pp. H396-H403 ◽  
Author(s):  
Larry J. Thompson ◽  
Jihong Jiang ◽  
Nageswara Madamanchi ◽  
Marschall S. Runge ◽  
Cam Patterson
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Tyrosine Phosphatase ◽  
Critical Role ◽  
Functional Characterization ◽  
Endothelial Cell Proliferation ◽  
Vascular Events ◽  
Protein Tyrosine

The vascular endothelium is a dynamic interface between the blood vessel and circulating factors and, as such, plays a critical role in vascular events like inflammation, angiogenesis, and hemostasis. Whereas specific protein tyrosine kinases have been identified in these processes, less is known about their protein tyrosine phosphatase (PTP) counterparts. We utilized a RT-PCR/differential hybridization assay to identify PTP-ε as a highly abundant endothelial cell PTP. PTP-ε mRNA expression is growth factor responsive, suggesting a role for this enzyme in endothelial cell proliferation. Overexpression of PTP-ε decreases proliferation by 60% in human umbilical vein endothelial cells (HUVEC) but not in smooth muscle cells or fibroblasts. In contrast, overexpression of PTP-ε (D284A), a catalytically inactive mutant, has no significant effect on HUVEC proliferation. These data provide the first functional characterization of PTP-ε in endothelial cells and identify a novel pathway that negatively regulates endothelial cell growth. Such a pathway may have important implications in vascular development and angiogenesis.

INHIBITION OF ENDOTHELIAL CELL PROLIFERATION BY NORMAL HUMAN MONOCYTES

1987 ◽  
Author(s):  
F Liote ◽  
M P Wautier ◽  
E Savariau ◽  
H Setiadi ◽  
J L Wautier
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
Thymidine Uptake ◽  
Blood Monocytes ◽  
Fibronectin Receptor

Human peripheral blood monocytes and macrophages possess factors which are capable of inhibiting or stimulating endothelial cell proliferation. We have further explored if such activity is due to cytotoxic effects of monocytes. Normal mononuclear cells were isolated first by density gradient. Monocytes were then purified by three different techniques: 1) counter centrifugation elutriation (CCE) (Beckman) 2) selective adhesion to gelatin-plasma (GPI) 3) selective adhesion to fibronectin (Fn). Cytotoxicity was estimated by counting the release of 51cr used to label the human umbilical vein endothelial cells (HUVE) prior to the addition of monocytes. Whilst [3H] thymidine incorporation by HUVE permitted us to measure the effect of monocytes on the growth of the endothelial cells. Monocytes were incubated with HUVE (12×103) for 24 to 36h at various concentrations '(1.5-12×103). No cytotoxic effect could be demonstrated but an inhibition of [3h] thymidine uptake was observed and was dependent upon monocytes concentration. Monocytes isolated on GP1 exhibited a significantly higher inhibitory effect (p<0.05) compared to those purified on Fn or by CCE.(GP1: 85±6%, Fn:58±6%, CCE:67±5%). These results indicated t*hat normal monocytes can inhibit endothelial cell proliferation. This activity appeared to be higher when monocytes were isolated on GP1 which suggest that the adhesion on this surface could stimulate monocytes not only by its fibronectin receptor. This inhibitory activity of monocyte on endothelial cells proliferation could be different in patients with vascular disorders.

scholarly journals Human umbilical vein endothelial cells display high-affinity c-kit receptors and produce a soluble form of the c-kit receptor

Blood ◽  
1994 ◽  
Vol 83 (8) ◽  
pp. 2145-2152 ◽  
Author(s):  
VC Broudy ◽  
NL Kovach ◽  
LG Bennett ◽  
N Lin ◽  
FW Jacobsen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tissue Factor ◽  
Adhesion Molecule ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
High Affinity ◽  
Kit Receptor ◽  
Normal Human

Stem cell factor (SCF) is a hematopoietic growth factor produced by fibroblasts and endothelial cells that stimulates the growth of primitive hematopoietic cells. SCF triggers cell growth by binding to the c-kit receptor. Because endothelial cells can respond to certain hematopoietic growth factors, we tested human umbilical vein endothelial cells for display of the c-kit receptor and examined the effect of SCF on endothelial cell proliferation, adhesion molecule expression, and production of tissue factor. Quantitative binding experiments with 125I-SCF showed both high-affinity (Kd = 42 pmol/L) and low-affinity (Kd = 1.7 nmol/L) c-kit receptors. There were approximately 1,100 high-affinity c-kit receptors, and 5,400 low- affinity c-kit receptors per endothelial cell. Enzyme immunoassays showed that endothelial cells released soluble c-kit receptor and SCF. The transmembrane form of SCF was detected by indirect immunofluorescence analysis using monoclonal or polyclonal anti-SCF receptor antibodies. The addition of SCF (100 ng/mL) did not alter endothelial cell proliferation over a 7-day period. Similarly, there was no change in the release of tissue factor or expression of inducible endothelial adhesion molecules (intercellular adhesion molecule-1, endothelial-leukocyte adhesion molecule-1, and vascular cell adhesion molecule-1) measured by enzyme-linked immunosorbant assay at 4 and 24 hours after SCF addition. The neutralizing anti-c-kit receptor monoclonal antibody SR-1 blocked binding of 125I-SCF to the c- kit receptor by 98% but did not alter endothelial cell proliferation or adhesion-molecule expression. c-kit receptors were also detected on adult endothelial cells lining small blood vessels in normal human lymph nodes. These data indicate that normal human endothelial cells produce SCF and show high-affinity c-kit receptors that have the capacity to dimerize. The lack of response to exogenous SCF may be because of intracellular activation of the c-kit receptor via autocrine production of SCF. Alternatively, SCF and c-kit may play a role other than stimulation of proliferation, adhesion-molecule display, or tissue factor production by endothelial cells. The production of soluble c-kit receptors by normal human endothelial cells may serve to regulate the bioactivity of SCF within the bone marrow microenvironment.

Covalently grafted VEGF165 in hydrogel models upregulates the cellular pathways associated with angiogenesis

2011 ◽  
Vol 301 (5) ◽  
pp. C1086-C1092 ◽  
Author(s):  
A. M. Porter ◽  
C. M. Klinge ◽  
A. S. Gobin
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Biological Response ◽  
Biomedical Science ◽  
Endothelial Cell Proliferation ◽  
Peg Hydrogels

Angiogenesis is an important biological response known to be involved in many physiological and pathophysiological situations. Cellular responses involved in the formation of new blood vessels, such as increases in endothelial cell proliferation, cell migration, and the survival of apoptosis-inducing events, have been associated with vascular endothelial growth factor isoform 165 (VEGF165). Current research in the areas of bioengineering and biomedical science has focused on developing polyethylene glycol (PEG)-based systems capable of initiating and sustaining angiogenesis in vitro. However, a thorough understanding of how endothelial cells respond at the molecular level to VEGF165 incorporated into these systems has not yet been established in the literature. The goal of the current study was to compare the upregulation of key intracellular proteins involved in angiogenesis in human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC) seeded on PEG hydrogels containing grafted VEGF165 and adhesion peptides Arg-Gly-Asp-Ser (RGDS). Our data suggest that the covalent incorporation of VEGF165 into PEG hydrogels encourages the upregulation of signaling proteins responsible for increases in endothelial cell proliferation, cell migration, and the survival after apoptosis-inducing events.

scholarly journals Human umbilical vein endothelial cells display high-affinity c-kit receptors and produce a soluble form of the c-kit receptor

Blood ◽  
1994 ◽  
Vol 83 (8) ◽  
pp. 2145-2152 ◽  
Author(s):  
VC Broudy ◽  
NL Kovach ◽  
LG Bennett ◽  
N Lin ◽  
FW Jacobsen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tissue Factor ◽  
Adhesion Molecule ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
High Affinity ◽  
Kit Receptor ◽  
Normal Human

Abstract Stem cell factor (SCF) is a hematopoietic growth factor produced by fibroblasts and endothelial cells that stimulates the growth of primitive hematopoietic cells. SCF triggers cell growth by binding to the c-kit receptor. Because endothelial cells can respond to certain hematopoietic growth factors, we tested human umbilical vein endothelial cells for display of the c-kit receptor and examined the effect of SCF on endothelial cell proliferation, adhesion molecule expression, and production of tissue factor. Quantitative binding experiments with 125I-SCF showed both high-affinity (Kd = 42 pmol/L) and low-affinity (Kd = 1.7 nmol/L) c-kit receptors. There were approximately 1,100 high-affinity c-kit receptors, and 5,400 low- affinity c-kit receptors per endothelial cell. Enzyme immunoassays showed that endothelial cells released soluble c-kit receptor and SCF. The transmembrane form of SCF was detected by indirect immunofluorescence analysis using monoclonal or polyclonal anti-SCF receptor antibodies. The addition of SCF (100 ng/mL) did not alter endothelial cell proliferation over a 7-day period. Similarly, there was no change in the release of tissue factor or expression of inducible endothelial adhesion molecules (intercellular adhesion molecule-1, endothelial-leukocyte adhesion molecule-1, and vascular cell adhesion molecule-1) measured by enzyme-linked immunosorbant assay at 4 and 24 hours after SCF addition. The neutralizing anti-c-kit receptor monoclonal antibody SR-1 blocked binding of 125I-SCF to the c- kit receptor by 98% but did not alter endothelial cell proliferation or adhesion-molecule expression. c-kit receptors were also detected on adult endothelial cells lining small blood vessels in normal human lymph nodes. These data indicate that normal human endothelial cells produce SCF and show high-affinity c-kit receptors that have the capacity to dimerize. The lack of response to exogenous SCF may be because of intracellular activation of the c-kit receptor via autocrine production of SCF. Alternatively, SCF and c-kit may play a role other than stimulation of proliferation, adhesion-molecule display, or tissue factor production by endothelial cells. The production of soluble c-kit receptors by normal human endothelial cells may serve to regulate the bioactivity of SCF within the bone marrow microenvironment.

scholarly journals The SRC Kinase Family Member Lymphocyte Specific Kinase (p56Lck) Regulates Endothelial Cell Proliferation and Survival

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1445-1445
Author(s):  
Venkaiah Betapudi ◽  
Sergei M. Merkoulov ◽  
Suman Kundu ◽  
Ou Ji ◽  
Meifang Wu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Tyrosine Kinases ◽  
Tube Formation ◽  
Protein Tyrosine Kinases ◽  
Endothelial Cell Proliferation ◽  
Protein Tyrosine ◽  
Lentiviral Transduction ◽  
Induction Of Apoptosis

Abstract Background and Objective: The Src family consists of Src, Lck (p56Lck), Fyn, Hck, Blk, Lyn, Fgr, Yes, and Yrk protein tyrosine kinases, which display cell and tissue specific expression. These non-receptor protein tyrosine kinases regulate many cellular processes including cell growth, differentiation, shape, migration, and survival. p56Lck is primarily expressed in T lymphocytes where it stimulates T cell receptor-mediated signaling to regulate thymocyte development. Similar to other SRC family members, p56Lck activity is negatively regulated by phosphorylation of Tyr505 and undergoes autophosphorylation on Tyr394 in the active state. Our previous studies showed that p56Lck activation occurred in proliferating endothelial cells exposed to cleaved high molecular weight kininogen (HKa), which induced endothelial cell apoptosis.The purpose of this study is to define the role of Lck in regulation of endothelial cell survival and angiogenesis. Methods: Primary cultures of endothelial cells were treated with Lck siRNA or with mammalian expression vectors or lentiviral constructs containing Lck cDNA. The proliferative capacity, viability, and tube-forming ability of Lck and control endothelial cells were determined. Results: Transfection of endothelial cells with Lck siRNA markedly changed their morphology and significantly enhanced their ability to proliferate in response to bFGF. In contrast, endothelial cells transfected with a Lck expression vector or transduced with a Lck-lentivirus not only failed to proliferate in response to growth factors, but also underwent apoptosis on several different extracellular matrix proteins. Finally, overexpression of Lck in endothelial cells led to impaired tube formation in a matrigel-based, in vitro angiogenesis assay; apoptosis of endothelial cells in this system was suggested by increased staining with Annexin V. Conclusion: Taken together, these results suggest that regulation of Lck activation provides a key node in determination of endothelial cell proliferation and survival that is likely to be relevant to the regulation of angiogenesis. Moreover, they suggest that specific endothelial cell Src family kinase members may play contrasting roles in regulation of these processes. Activation of Lck may represent a potential mechanism for controlling aberrant angiogenesis in pathological conditions. Figure: Effect of control or p56Lck-expressing lentiviral transduction on endothelial cell tube formation and induction of apoptosis. Figure:. Effect of control or p56Lck-expressing lentiviral transduction on endothelial cell tube formation and induction of apoptosis. Disclosures No relevant conflicts of interest to declare.

scholarly journals Role of protein tyrosine phosphatase 1B (PTP1B) in the increased sensitivity of endothelial cells to a promigratory effect of erythropoietin in an inflammatory environment

2020 ◽  
Vol 401 (10) ◽  
pp. 1167-1180
Author(s):  
María Eugenia Chamorro ◽  
Romina Maltaneri ◽  
Agustina Schiappacasse ◽  
Alcira Nesse ◽  
Daniela Vittori
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Cross Talk ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Endothelial Cell Migration ◽  
Protein Tyrosine Phosphatase 1B ◽  
Vascular Events ◽  
Protein Tyrosine ◽  
Sensitizing Effect

AbstractThe proliferation and migration of endothelial cells are vascular events of inflammation, a process which can also potentiate the effects of promigratory factors. With the aim of investigating possible modifications in the activity of erythropoietin (Epo) in an inflammatory environment, we found that Epo at a non-promigratory concentration was capable of stimulating EA.hy926 endothelial cell migration when TNF-α was present. VCAM-1 and ICAM-1 expression, as well as adhesion of monocytic THP-1 cells to endothelial layers were also increased. Structurally modified Epo (carbamylation or N-homocysteinylation) did not exhibit these effects. The sensitizing effect of TNF-α on Epo activity was mediated by the Epo receptor. Inhibition assays targeting the PI3K/mTOR/NF-κB pathway, shared by Epo and TNF-α, show a cross-talk between both cytokines. As observed in assays using antioxidants, cell migration elicited by TNF-α + Epo depended on TNF-α-generated reactive oxygen species (ROS). ROS-mediated inactivation of protein tyrosine phosphatase 1B (PTP1B), involved in Epo signaling termination, could explain the synergistic effect of these cytokines. Our results suggest that ROS generated by inflammation inactivate PTP1B, causing the Epo signal to last longer. This mechanism, along with the cross-talk between both cytokines, could explain the sensitizing action of TNF-α on the migratory effect of Epo.

scholarly journals Gold Nanoparticles Inhibit VEGF165-Induced Migration and Tube Formation of Endothelial Cells via the Akt Pathway

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yunlong Pan ◽  
Qing Wu ◽  
Li Qin ◽  
Jiye Cai ◽  
Bin Du
Keyword(s):  
Gold Nanoparticles ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Cell Surface ◽  
Umbilical Vein ◽  
Critical Role ◽  
Chorioallantoic Membrane ◽  
Tube Formation ◽  
Endothelial Cell Proliferation ◽  
Akt Pathway

The early stages of angiogenesis can be divided into three steps: endothelial cell proliferation, migration, and tube formation. Vascular endothelial growth factor (VEGF) is considered the most important proangiogenic factor; in particular, VEGF165plays a critical role in angiogenesis. Here, we evaluated whether gold nanoparticles (AuNPs) could inhibit the VEGF165-induced human umbilical vein endothelial cell (HUVEC) migration and tube formation. AuNPs and VEGF165were coincubated overnight at 4°C, after which the effects on cell migration and tube formation were assessed. Cell migration was assessed using a modified wound-healing assay and a transwell chamber assay; tube formation was assessed using a capillary-like tube formation assay and a chick chorioallantoic membrane (CAM) assay. We additionally detected the cell surface morphology and ultrastructure using atomic force microscopy (AFM). Furthermore, Akt phosphorylation downstream of VEGFR-2/PI3K in HUVECs was determined in a Western blot analysis. Our study demonstrated that AuNPs significantly inhibited VEGF165-induced HUVEC migration and tube formation by affecting the cell surface ultrastructure, cytoskeleton and might have inhibited angiogenesis via the Akt pathway.

Abstract 117: RhoC Regulates VEGF-induced Signaling in Endothelial Cells

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Luke Hoeppner ◽  
Sutapa Sinha ◽  
Ying Wang ◽  
Resham Bhattacharya ◽  
Shamit Dutta ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Permeability ◽  
Rho Gtpase ◽  
Endothelial Cell Migration ◽  
Calcium Flux ◽  
Endothelial Cell Proliferation ◽  
Vegf Receptor ◽  
Vegf Signaling

Vascular permeability factor/vascular endothelial growth factor A (VEGF) is a central regulator of angiogenesis and potently promotes vascular permeability. VEGF plays a key role in the pathologies of heart disease, stroke, and cancer. Therefore, understanding the molecular regulation of VEGF signaling is an important pursuit. Rho GTPase proteins play various roles in vasculogenesis and angiogenesis. While the functions of RhoA and RhoB in these processes have been well defined, little is known about the role of RhoC in VEGF-mediated signaling in endothelial cells and vascular development. Here, we describe how RhoC modulates VEGF signaling to regulate endothelial cell proliferation, migration and permeability. We found VEGF stimulation activates RhoC in human umbilical vein endothelial cells (HUVECs), which was completely blocked after VEGF receptor 2 (VEGFR-2) knockdown indicating that VEGF activates RhoC through VEGFR-2 signaling. Interestingly, RhoC knockdown delayed the degradation of VEGFR-2 compared to control siRNA treated HUVECs, thus implicating RhoC in VEGFR-2 trafficking. In light of our results suggesting VEGF activates RhoC through VEGFR-2, we sought to determine whether RhoC regulates vascular permeability through the VEGFR-2/phospholipase Cγ (PLCγ) /Ca 2+ /eNOS cascade. We found RhoC knockdown in VEGF-stimulated HUVECs significantly increased PLC-γ1 phosphorylation at tyrosine 783, promoted basal and VEGF-stimulated eNOS phophorylation at serine 1177, and increased calcium flux compared with control siRNA transfected HUVECs. Taken together, our findings suggest RhoC negatively regulates VEGF-induced vascular permeability. We confirmed this finding through a VEGF-inducible zebrafish model of vascular permeability by observing significantly greater vascular permeability in RhoC morpholino (MO)-injected zebrafish than control MO-injected zebrafish. Furthermore, we showed that RhoC promotes endothelial cell proliferation and negatively regulates endothelial cell migration. Our data suggests a scenario in which RhoC promotes proliferation by upregulating -catenin in a Wnt signaling-independent manner, which in turn, promotes Cyclin D1 expression and subsequently drives cell cycle progression.

The role of matrix metalloproteinase activity in the maturation of human capillary endothelial cells in vitro

1999 ◽  
Vol 112 (10) ◽  
pp. 1599-1609 ◽  
Author(s):  
B.M. Kraling ◽  
D.G. Wiederschain ◽  
T. Boehm ◽  
M. Rehn ◽  
J.B. Mulliken ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Cell Proliferation ◽  
Protein Levels ◽  
Matrix Deposition ◽  
Capillary Endothelial Cells ◽  
Vessel Maturation

Vessel maturation during angiogenesis (the formation of new blood vessels) is characterized by the deposition of new basement membrane and the downregulation of endothelial cell proliferation in the new vessels. Matrix remodeling plays a crucial, but still poorly understood role, in angiogenesis regulation. We present here a novel assay system with which to study the maturation of human capillary endothelial cells in vitro. When human dermal microvascular endothelial cells (HDMEC) were cultured in the presence of dibutyryl cAMP (Bt2) and hydrocortisone (HC), the deposition of a fibrous lattice of matrix molecules consisting of collagens type IV, type XVIII, laminin and thrombospondin was induced. In basal medium (without Bt2 and HC), HDMEC released active matrix metalloproteinases (MMPs) into the culture medium. However, MMP protein levels were significantly reduced by treatment with Bt2 and HC, while protein levels and activity of endogenous tissue inhibitor of MMPs (TIMP) increased. This shift in the proteolytic balance and matrix deposition was inhibited by the specific protein kinase A inhibitors RpcAMP and KT5720 or by substituting analogues without reported glucocorticoid activity for HC. The addition of MMP inhibitors human recombinant TIMP-1 or 1,10-phenanthroline to cultures under basal conditions induced matrix deposition in a dose-dependent manner, which was not observed with the serine protease inhibitor epsilon-amino-n-caproic acid (ACA). The deposited basement membrane-type of matrix reproducibly suppressed HDMEC proliferation and increased HDMEC adhesion to the substratum. These processes of matrix deposition and downregulation of endothelial cell proliferation, hallmarks of differentiating new capillaries in the end of angiogenesis, were recapitulated in our cell culture system by decreasing the matrix-degrading activity. These data suggest that our cell culture assay provides a simple and feasible model system for the study of capillary endothelial cell differentiation and vessel maturation in vitro.

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