scholarly journals Hypoxia Stimulates Urokinase Receptor Expression Through a Heme Protein-Dependent Pathway

Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3300-3307 ◽  
Author(s):  
Charles H. Graham ◽  
Tania E. Fitzpatrick ◽  
Keith R. McCrae
Keyword(s):  
Plasminogen Activator ◽  
Umbilical Vein ◽  
Heme Protein ◽  
Receptor Expression ◽  
Cellular Migration ◽  
Migration And Invasion ◽  
Mrna Levels ◽  
Upar Expression ◽  
Dependent Pathway ◽  
Cells Cultured

Abstract Hypoxia underlies a number of biologic processes in which cellular migration and invasion occur. Because earlier studies have shown that the receptor for urokinase-type plasminogen activator (uPAR) may facilitate such events, we studied the effect of hypoxia on the expression of uPAR by first trimester human trophoblasts (HTR-8/SVneo) and human umbilical vein endothelial cells (HUVEC). Compared with control cells cultured under standard conditions (20% O2), HTR-8/SVneo cells and HUVEC cultured in 1% O2 expressed more uPAR, as determined by flow cytometric and [125I]-prourokinase ligand binding analyses. Increased uPAR expression paralleled increases in uPAR mRNA. The involvement of a heme protein in the hypoxia-induced expression of uPAR was suggested by the observations that culture of cells with cobalt chloride, or sodium 4,5-dihydroxybenzene-1,3-disulfonate (Tiron), an iron-chelating agent, also stimulated uPAR expression, and that the hypoxia-induced uPAR expression was inhibited by adding carbon monoxide to the hypoxic atmosphere. Culture of HTR-8/SVneo cells with vascular endothelial growth factor (VEGF) did not increase uPAR mRNA levels, suggesting that the hypoxia-mediated effect on uPAR expression by these cells did not occur through a VEGF-dependent mechanism. The functional importance of these findings is suggested by the fact that HTR-8/SVneo cells cultured under hypoxia displayed higher levels of cell surface plasminogen activator activity and greater invasion through a reconstituted basement membrane. These results suggest that hypoxia may promote cellular invasion by stimulating the expression of uPAR through a heme protein-dependent pathway.

scholarly journals Hypoxia Stimulates Urokinase Receptor Expression Through a Heme Protein-Dependent Pathway

Blood ◽  
1998 ◽  
Vol 91 (9) ◽  
pp. 3300-3307 ◽  
Author(s):  
Charles H. Graham ◽  
Tania E. Fitzpatrick ◽  
Keith R. McCrae
Keyword(s):  
Plasminogen Activator ◽  
Umbilical Vein ◽  
Heme Protein ◽  
Receptor Expression ◽  
Cellular Migration ◽  
Migration And Invasion ◽  
Mrna Levels ◽  
Upar Expression ◽  
Dependent Pathway ◽  
Cells Cultured

Hypoxia underlies a number of biologic processes in which cellular migration and invasion occur. Because earlier studies have shown that the receptor for urokinase-type plasminogen activator (uPAR) may facilitate such events, we studied the effect of hypoxia on the expression of uPAR by first trimester human trophoblasts (HTR-8/SVneo) and human umbilical vein endothelial cells (HUVEC). Compared with control cells cultured under standard conditions (20% O2), HTR-8/SVneo cells and HUVEC cultured in 1% O2 expressed more uPAR, as determined by flow cytometric and [125I]-prourokinase ligand binding analyses. Increased uPAR expression paralleled increases in uPAR mRNA. The involvement of a heme protein in the hypoxia-induced expression of uPAR was suggested by the observations that culture of cells with cobalt chloride, or sodium 4,5-dihydroxybenzene-1,3-disulfonate (Tiron), an iron-chelating agent, also stimulated uPAR expression, and that the hypoxia-induced uPAR expression was inhibited by adding carbon monoxide to the hypoxic atmosphere. Culture of HTR-8/SVneo cells with vascular endothelial growth factor (VEGF) did not increase uPAR mRNA levels, suggesting that the hypoxia-mediated effect on uPAR expression by these cells did not occur through a VEGF-dependent mechanism. The functional importance of these findings is suggested by the fact that HTR-8/SVneo cells cultured under hypoxia displayed higher levels of cell surface plasminogen activator activity and greater invasion through a reconstituted basement membrane. These results suggest that hypoxia may promote cellular invasion by stimulating the expression of uPAR through a heme protein-dependent 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.

Fluvastatin Inhibits Basal and Stimulated Plasminogen Activator Inhibitor 1, but Induces Tissue Type Plasminogen Activator in Cultured Human Endothelial Cells

2000 ◽  
Vol 84 (07) ◽  
pp. 59-64 ◽  
Author(s):  
Luciana Mussoni ◽  
Cristina Banfi ◽  
Luigi Sironi ◽  
Magda Arpaia ◽  
Elena Tremoli
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
De Novo ◽  
Umbilical Vein ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

SummaryThe effects of fluvastatin, a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) inhibitor, on the biosynthesis of tissue plasminogen activator (t-PA) and of its major physiological inhibitor (plasminogen activator inhibitor type 1, PAI-1) were investigated in cultured human umbilical vein endothelial cells (HUVEC). Fluvastatin (0.1 to 2.5 µM), concentration-dependently reduced the release of PAI-1 antigen by unstimulated HUVEC, subsequent to a reduction in PAI-1 steady-state mRNA levels and de novo protein synthesis. In contrast, it increased t-PA secretion.The drug also reduced PAI-1 antigen secreted in response to 10 µg/ml bacterial lipopolysaccharide (LPS), 100 U/ml tumour necrosis factor α (TNFα) or 0.1 µM phorbol myristate acetate (PMA).Mevalonate (100 µM), a precursor of isoprenoids, added to cells simultaneously with fluvastatin, suppressed the effect of the drug on PAI-1 both in unstimulated and stimulated cells as well as on t-PA antigen. Among intermediates of the isoprenoid pathway, all-trans-geranylgeraniol (5 µM) but not farnesol (10 µM) prevented the effect of 2.5 µM fluvastatin on PAI-1 antigen, which suggests that the former intermediate of the isoprenoid synthesis is responsible for the observed effects.

Cytokine Regulation of the Synthesis of Plasminogen Activator Inhibitor-2 by Human Vascular Endothelial Cells

1993 ◽  
Vol 69 (02) ◽  
pp. 135-140 ◽  
Author(s):  
Hans Zoellner ◽  
Johann Wojta ◽  
Marisa Gallicchio ◽  
Katherine McGrath ◽  
John A Hamilton
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Vascular Endothelial Cells ◽  
Thrombus Formation ◽  
Umbilical Vein ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Pai 1

SummaryPlasminogen activators are inhibited by plasminogen activator inhibitors-1 (PAI-1) and -2 (PAI-2). We describe the synthesis of PAI-2 by human vascular endothelial cells (EC) cultured from umbilical vein, saphenous vein and foreskin microvasculature in response to interleukin-1α (IL־1α) and tumour necrosis factor α (TNFα) and compare it with that of PAI-1. Both PAI-2 and PAI-1 were quantitated by ELIS As. PAI-2 was cell-associated while PAI-1 was secreted by EC. IL-lα and TNFα increased the synthesis of PAI-2 and PAI-1 by EC in a dose-dependent manner. IL-1α was a stronger stimulus for PAI-2 synthesis than TNFα, while both cytokines were equally effective for PAI-1. Northern blot analysis revealed similar changes in mRNA levels to those in antigen levels. PAI-2 synthesis by cytokine-stimulated EC may be important in thrombus formation and inflammation.

scholarly journals Thrombin regulation of mRNA levels of tissue plasminogen activator and plasminogen activator inhibitor-1 in cultured human umbilical vein endothelial cells

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 222-228 ◽  
Author(s):  
D Dichek ◽  
T Quertermous
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Umbilical Vein ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Human Umbilical Vein ◽  
Tissue Plasminogen ◽  
Umbilical Vein Endothelial Cells ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Cultured human umbilical vein endothelial cells release tissue plasminogen activator (t-PA) and type 1 plasminogen activator inhibitor (PAI-1) in response to alpha thrombin stimulation. In order to study the mechanisms of thrombin stimulation, we measured changes in levels of mRNA for t-PA and PAI-1 following exposure of endothelial cells to 3 U/mL alpha thrombin. Alpha thrombin causes a significant and time- dependent increase in the mRNA levels of both t-PA and PAI-1. Catalytically inactivated diisofluorophosphate (DIP) treated thrombin and alpha thrombin pretreated with hirudin do not alter t-PA and PAI-1 mRNA levels. We conclude that the increased secretion of t-PA and PAI-1 by human umbilical vein endothelial cells in response to alpha thrombin is mediated at least partially through an increase in mRNA levels. In addition, an active thrombin catalytic site is required for these increases in mRNA to occur.

scholarly journals Thrombin regulation of mRNA levels of tissue plasminogen activator and plasminogen activator inhibitor-1 in cultured human umbilical vein endothelial cells

Blood ◽  
1989 ◽  
Vol 74 (1) ◽  
pp. 222-228 ◽  
Author(s):  
D Dichek ◽  
T Quertermous
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Umbilical Vein ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Human Umbilical Vein ◽  
Tissue Plasminogen ◽  
Umbilical Vein Endothelial Cells ◽  
Activator Inhibitor ◽  
Pai 1

Cultured human umbilical vein endothelial cells release tissue plasminogen activator (t-PA) and type 1 plasminogen activator inhibitor (PAI-1) in response to alpha thrombin stimulation. In order to study the mechanisms of thrombin stimulation, we measured changes in levels of mRNA for t-PA and PAI-1 following exposure of endothelial cells to 3 U/mL alpha thrombin. Alpha thrombin causes a significant and time- dependent increase in the mRNA levels of both t-PA and PAI-1. Catalytically inactivated diisofluorophosphate (DIP) treated thrombin and alpha thrombin pretreated with hirudin do not alter t-PA and PAI-1 mRNA levels. We conclude that the increased secretion of t-PA and PAI-1 by human umbilical vein endothelial cells in response to alpha thrombin is mediated at least partially through an increase in mRNA levels. In addition, an active thrombin catalytic site is required for these increases in mRNA to occur.

scholarly journals Prognostic Impact of Urokinase Plasminogen Activator Receptor Expression in Pancreatic Cancer: Malignant Versus Stromal Cells

2017 ◽  
Vol 12 ◽  
pp. 117727191771544 ◽  
Author(s):  
Susanna WL de Geus ◽  
Victor M Baart ◽  
Martin C Boonstra ◽  
Peter JK Kuppen ◽  
Hendrica AJM Prevoo ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Plasminogen Activator ◽  
Stromal Cells ◽  
Urokinase Plasminogen Activator ◽  
Receptor Expression ◽  
Prognostic Impact ◽  
Urokinase Plasminogen Activator Receptor ◽  
Neoplastic Cells ◽  
Upar Expression ◽  
Plasminogen Activator Receptor

The urokinase plasminogen activator receptor (uPAR) has been proposed as a potential prognostic factor for various malignancies. The aim of this study is to assess the prognostic value of uPAR expression in neoplastic and stromal cells of patients with pancreatic adenocarcinoma. Urokinase plasminogen activator receptor expression was determined by immunohistochemistry in 122 pancreatic ductal adenocarcinomas. Kaplan-Meier and Cox regression analyses were used to determine the association with survival. Respectively 66%, 82% and 62% of patients with pancreatic cancer expressed uPAR in neoplastic cells, stromal, and in both combined. Multivariate analysis showed a significant inverse association between uPAR expression in both neoplastic and stromal cells and overall survival. The prognostic impact of uPAR in stromal cells is substantial, but not as pronounced as that of uPAR expression in neoplastic cells. This study suggests a role for uPAR as a biomarker to single out higher risk subgroups of patients with pancreatic cancer.

scholarly journals SalA Attenuates Hypoxia-Induced Endothelial Endoplasmic Reticulum Stress and Apoptosis via Down-Regulation of VLDL Receptor Expression

2015 ◽  
Vol 35 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Ping Xie ◽  
Yingchun Duan ◽  
Xianzhi Guo ◽  
Lina Hu ◽  
Minghua Yu
Keyword(s):  
Endothelial Cells ◽  
Er Stress ◽  
Umbilical Vein ◽  
Gene Promoter ◽  
Immunoblot Analysis ◽  
Receptor Expression ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Luciferase Reporter Gene ◽  
Vldl Receptor

Background: Salvianolic acid A (SalA) has been shown to display robust protection against endothelial injury. VLDL receptor (VLDLr) is expressed at high levels in the endothelial cells. However its endothelial biological function has not been completely elucidated. Here, we investigated molecular effects of SalA on endothelial VLDLr expression, ER stress, and apoptosis under hypoxia condition. Methods: Human umbilical vein endothelial cells (HUVECs) pretreated with SalA were subjected to hypoxia stimulation. Endothelial ER stress and apoptosis were examined. The mRNA levels were tested by real-time RT-PCR, and the protein levels were determined by immunoblot analysis. Results: Pretreatment of HUVECs with SalA markedly attenuated hypoxia-induced endothelial ER stress and apoptosis. Hypoxia resulted in enhancement of VLDLr expression, which was effectively inhibited by SalA pretreatment. Furthermore, luciferase reporter gene assays indicated that SalA inhibited vldlr gene promoter activity, and ChIP assays showed that hypoxia increase the recruitment of HIF-1α to the vldlr gene promoter, and this process was hampered markedly by pretreatment of SalA. Finally, overexpression of VLDLr abolished SalA-mediated protection of endothelial cells from ER stress and apoptosis. Knockdown of VLDLr mimicked SalA protective effect. Conclusion: These results for the first time demonstrate that SalA protects against hypoxia-induced endothelial ER stress and apoptosis through inhibiting recruitment of HIF-1α to vldlr gene promoter and thus suppressing VLDLr expression.

Single-Chain and Two-Chain Tissue-Type Plasminogen Activator (t-PA) Bind Differently to Cultured Human Endothelial Cells

1989 ◽  
Vol 62 (02) ◽  
pp. 699-703 ◽  
Author(s):  
Rob J Aerts ◽  
Karin Gillis ◽  
Hans Pannekoek
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Tissue Type ◽  
Single Chain ◽  
Human Endothelial Cells ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Umbilical Vein Endothelial Cells

SummaryIt has recently been shown that the fibrinolytic components plasminogen and tissue-type plasminogen activator (t-PA) both bind to cultured human umbilical vein endothelial cells (HUVEC). After cleavage of t-PA by plasmin, “single-chain” t-PA (sct-PA) is converted into “two-chain” t-PA (tct-PA), which differs from the former in a number of respects. We compared binding of sct-PA and tct-PA to the surface of HUVEC. Removal of t-PA bound to HUVEC by a mild treatment with acid and a subsequent quantification of eluted t-PA both by activity- and immunoradiometric assays revealed that, at concentrations between 10 and 500 nM, HUVEC bind about 3-4 times more sct-PA than tct-PA. At these concentrations, both sct-PA and tct-PA remain active when bound to HUVEC. Mutual competition experiments showed that sct-PA and tct-PA can virtually fully inhibit binding of each other to HUVEC, but that an about twofold higher concentration of tct-PA is required to prevent halfmaximal binding of sct-PA than visa versa. These results demonstrate that sct-PA and tct-PA bind with different affinities to the same binding sites on HUVEC.

Effect of Lipoprotein(a) and LDL on Plasminogen Binding to Extracellular Matrix and on Matrix-dependent Plasminogen Activation by Tissue Plasminogen Activator

1996 ◽  
Vol 75 (03) ◽  
pp. 497-502 ◽  
Author(s):  
Hadewijch L M Pekelharing ◽  
Henne A Kleinveld ◽  
Pieter F C.C.M Duif ◽  
Bonno N Bouma ◽  
Herman J M van Rijn
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Binding Sites ◽  
Umbilical Vein ◽  
Single Step ◽  
Plasminogen Activation ◽  
Structural Homology ◽  
Tissue Plasminogen ◽  
Umbilical Vein Endothelial Cells

SummaryLp(a) is an LDL-like lipoprotein plus an additional apolipoprotein apo(a). Based on the structural homology of apo(a) with plasminogen, it is hypothesized that Lp(a) interferes with fibrinolysis. Extracellular matrix (ECM) produced by human umbilical vein endothelial cells was used to study the effect of Lp(a) and LDL on plasminogen binding and activation. Both lipoproteins were isolated from the same plasma in a single step. Plasminogen bound to ECM via its lysine binding sites. Lp(a) as well as LDL were capable of competing with plasminogen binding. The degree of inhibition was dependent on the lipoprotein donor as well as the ECM donor. When Lp(a) and LDL obtained from one donor were compared, Lp(a) was always a much more potent competitor. The effect of both lipoproteins on plasminogen binding was reflected in their effect on plasminogen activation. It is speculated that Lp(a) interacts with ECM via its LDL-like lipoprotein moiety as well as via its apo(a) moiety.

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