Mechanisms by which cleaved kininogen inhibits endothelial cell differentiation and signalling

2010 ◽  
Vol 104 (11) ◽  
pp. 875-885 ◽  
Author(s):  
Yi Wu ◽  
Yuchuan Liu ◽  
Robert Colman
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Urokinase Plasminogen Activator ◽  
Inhibitory Effect ◽  
Tube Formation ◽  
Dependent Manner ◽  
Urokinase Plasminogen Activator Receptor ◽  
Concentration Dependent Manner ◽  
Erk Activation ◽  
Extracellular Signal

SummaryWe have shown that cleaved high-molecular-weight kininogen inhibits endoththelial cell tube and vacuole formation in a concentration-dependent manner and this correlates with its recognised anti-angiogenic activity. The antibody against the urokinase plasminogen activator receptor (uPAR) mimicked the inhibitory effect of cleaved kininogen (HKa) on apoptosis (HKa: 30% and uPAR antibody: 26%) and tube formation. In tumour angiogenesis, cancer cells release angiogenic stimulators, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), thus stimulating the transformation of endogenous pro-uPA to uPA. The proteolytic enzyme urokinase plasminogen activator (uPA) then binds to its receptor in a complex with its inhibitor PAI-1, which results in the internalisation of this complex, and activates extracellular signal-regulated kinase (ERK). Recycling of the uPAR regulates the migration of endothelial cells (ECs). ERK activation stimulates migration and proliferation and suppresses apoptosis of ECs. HKa disrupted the uPA-uPAR complex, inhibited ERK activation, and blocked the internalization of uPAR, eventually resulting in cell death and cell motility arrest. Both are critical steps in angiogenesis.

Thrombin activatable fibrinolysis inhibitor (TAFI) affects fibrinolysis in a plasminogen activator concentration-dependent manner

2004 ◽  
Vol 91 (03) ◽  
pp. 473-479 ◽  
Author(s):  
Ana Guimarães ◽  
Dingeman Rijken
Keyword(s):  
Plasminogen Activator ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Retardation Factor ◽  
Clot Lysis ◽  
Dependent Manner ◽  
Plasma Clot ◽  
Concentration Dependent Manner ◽  
Plasmin Inhibitor

SummaryTAFIa was shown to attenuate fibrinolysis. In our in vitro study, we investigated how the inhibitory effect of TAFIa depended on the type and concentration of the plasminogen activator (PA). We measured PA-mediated lysis times of plasma clots under conditions of maximal TAFI activation by thrombin-thrombomodulin in the absence and presence of potato carboxypeptidase inhibitor. Seven different PAs were compared comprising both tPA-related (tPA, TNK-tPA, DSPA), bacterial PA-related (staphylokinase and APSAC) and urokinase-related (tcu-PA and k2tu-PA) PAs. The lysis times and the retardation factor were plotted against the PA concentration. The retardation factor plots were bell-shaped. At low PA concentrations, the retardation factor was low, probably due to the limited stability of TAFIa. At intermediate PA concentrations the retardation factor was maximal (3-6 depending on the PA), with TNK-tPA, APSAC and DSPA exhibiting the strongest effect. At high PA concentrations, the retardation factor was again low, possibly due to inactivation of TAFIa by plasmin or to a complete conversion of glu-plasminogen into lys-plasminogen. Using individual plasmas with a reduced plasmin inhibitor activity (plasmin inhibitor Enschede) the bell-shaped curve of the retardation factor shifted towards lower tPA and DSPA concentrations, but the height did not decrease. In conclusion, TAFIa delays the lysis of plasma clots mediated by all the plasminogen activators tested. This delay is dependent on the type and concentration of the plasminogen activator, but not on the fibrin specificity of the plasminogen activator. Furthermore, plasmin inhibitor does not play a significant role in the inhibition of plasma clot lysis by TAFI.

scholarly journals Regulation of Rat Mesangial Cell Migration by Platelet-Derived Growth Factor, Angiotensin II, and Adrenomedullin

1999 ◽  
Vol 10 (12) ◽  
pp. 2495-2502 ◽  
Author(s):  
MASAKAZU KOHNO ◽  
KENICHI YASUNARI ◽  
MIEKO MINAMI ◽  
HIROAKI KANO ◽  
KENSAKU MAEDA ◽  
...  
Keyword(s):  
Cell Migration ◽  
Angiotensin Ii ◽  
Growth Factor ◽  
Mesangial Cell ◽  
Mesangial Cells ◽  
Inhibitory Effect ◽  
Platelet Derived Growth Factor ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Concentration Dependent Manner

Abstract. This study sought to determine whether platelet-derived growth factor (PDGF) and angiotensin II (AngII) stimulate migration of cultured rat glomerular mesangial cells. After finding that this was so, the effects of adrenomedullin (ADM) and cAMP-elevating agents on basal and stimulated mesangial cell migration were examined. Two isoforms of PDGF, AB and BB, stimulated migration in a concentration-dependent manner between 1 and 50 ng/ml, while the AA isoform lacked significant effect. AngII modestly but significantly stimulated migration in a concentration-dependent manner between 10-7 and 10-6 mol/L. Rat ADM significantly inhibited the PDGF BB- and AngII-stimulated migration in a concentration-dependent manner between 10-8 and 10-7 mol/L. Inhibition by rat ADM was accompanied by an increase in cellular cAMP. cAMP agonists or inducers such as 8-bromo cAMP, forskolin, and prostaglandin I2 also significantly reduced the stimulated migration. H 89, a protein kinase A (PKA) inhibitor, attenuated the inhibitory effect of ADM, and a calcitonin gene-related peptide (CGRP) receptor antagonist, human CGRP (8-37), abolished the inhibitory effects of rat ADM. These results suggest that PDGF AB and BB as well as AngII stimulate rat mesangial cell migration and that ADM can inhibit PDGF BB- and AngII-stimulated migration, at least in part through cAMP-dependent mechanisms likely to involve specific ADM receptors with which CGRP interacts. The adenylate cyclase/cAMP/PKA system may be involved in the migration-inhibitory effect of ADM in these cells.

scholarly journals Anti-Angiogenic Effect of Asperchalasine A Via Attenuation of VEGF Signaling

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 358 ◽  
Author(s):  
Jun Yeon Park ◽  
Young Seok Ji ◽  
Hucheng Zhu ◽  
Yonghui Zhang ◽  
Do Hwi Park ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Umbilical Vein ◽  
Chorioallantoic Membrane ◽  
Growth Factor Receptor ◽  
Tube Formation ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Concentration Dependent Manner ◽  
Endothelial Growth Factor

Cytochalasans are a group of structurally diverse fungal polyketide-amino acid hybrid metabolites that exhibit diverse biological functions. Asperchalasine A was identified and isolated from an extract of the marine-derived fungus, Aspergillus. Asperchalasine A is a cytochalasan dimer which consists of two cytochalasan molecules connected by an epicoccine. This study investigated the potential antiangiogenic effects of Aspergillus extract and asperchalasine A, which significantly inhibited cell adhesion and tube formation in human umbilical vein endothelial cells (HUVECs). Aspergillus extract and asperchalasine A decreased the vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR)-2 mRNA expression in a concentration-dependent manner. In addition, Aspergillus extract and asperchalasine A inhibited angiogenesis via downregulation of VEGF, p-p38, p-extracellular signal-regulated protein kinase (ERK), p-VEGFR-2, and p-Akt signaling pathways. Moreover, Aspergillus extract and asperchalasine A significantly inhibited the amount of blood vessel formation in fertilized chicken eggs using a chorioallantoic membrane assay. Our results provide experimental evidence of this novel biological activity of the potential antiangiogenic substances, Aspergillus extract, and asperchalasine A. This study also suggests that Aspergillus extract and its active component asperchalasine A are excellent candidates as adjuvant therapeutic substances for cancer prevention and treatment.

scholarly journals Timosaponin AIII Suppresses Hepatocyte Growth Factor-Induced Invasive Activity through Sustained ERK Activation in Breast Cancer MDA-MB-231 Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Chung-Hsin Tsai ◽  
Chu-Wen Yang ◽  
Jir-You Wang ◽  
Yi-Fang Tsai ◽  
Ling-Ming Tseng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Cancer Cell Line ◽  
Dependent Manner ◽  
Subsequent Increase ◽  
Concentration Dependent Manner ◽  
Erk Activation ◽  
Hepatocyte Growth ◽  
Timosaponin Aiii

Background. The aim of this study was to investigate the mechanisms by which Timosaponin AIII (TAIII) is able to inhibit HGF-induced invasion activity in the triple negative breast cancer cell line MDA-MB-231.Methods. After pretreatment with different concentrations (10−6~10−8 M) of TAIII, the cells were treated with hepatocyte growth factor (HGF, 15 ng/mL). At different time intervals after coincubation, various parameters, including the expression of c-Met, ERK, COX2, and MMP-9, which were assessed by Western blotting or by real-time PCR, were analyzed. In addition, invasive activity was also monitored.Results. HGF was found to induce c-MET activation and ERK activation, together with increased COX2 protein expression; these changes were followed by a subsequent increase in invasive activity. TAIII was found to suppress HGF-induced invasive activity andCOX2gene expression in a concentration-dependent manner (10−6~10−8 M) in parallel with increases in the phosphoforms of c-Met and ERK after TAIII treatment. The mechanisms by which TAIII suppresses HGF-induced invasive activity were demonstrated to include sustained cytoplasmic and nuclear ERK activation; these led to a suppression of nuclear ATF2 activation, which was followed by downregulation ofCOX2andMMP-9transcription.Conclusion. TAIII suppresses HGF-induced invasive activity in MDA-MB-231 cells via sustained ERK activation.

scholarly journals Inhibition of human and ovine acrosomal enzymes by tannic acid in vitro

Reproduction ◽  
2001 ◽  
pp. 131-137 ◽  
Author(s):  
IA Taitzoglou ◽  
M Tsantarliotou ◽  
I Zervos ◽  
D Kouretas ◽  
NA Kokolis
Keyword(s):  
Plasminogen Activator ◽  
Tannic Acid ◽  
Inhibitory Effect ◽  
Tissue Type ◽  
Dependent Manner ◽  
Plasmin Activity ◽  
Concentration Dependent Manner ◽  
Plasminogen Activator Activity ◽  
Type Plasminogen Activator

The effect of tannic acid, a common flavonoid, on the acrosin and plasminogen activator activity and plasmin activity of human and ram spermatozoa was evaluated. Acrosin and plasminogen activator activity were determined by spectrophotometry using the chromogenic substrates N-alpha-benzoyl-DL-arginine para-nitroanilide-HCl (BAPNA) and H-D-valyl-L-leucyl-L-lysine-p-nitroanilide-2HCl (S-2251), respectively. In extracts from both human and ovine acrosomes, the activities of acrosin and plasminogen activators were susceptible to tannic acid inhibition. The inhibitory effect of tannic acid was observed at concentrations > 50 micromol l(-1) in a dose-dependent manner. In additional experiments, low concentrations of tannic acid significantly inhibited tissue-type plasminogen activator, urokinase-type plasminogen activator and plasmin activity in a concentration-dependent manner over the range 0.25-200 micromol l(-1). Tannic acid reduced the motility of ram spermatozoa at a concentration of 1000 micromol l(-1) after 2 and 3 h co-incubation with spermatozoa. The motility of human spermatozoa remained unchanged over the range 0.1-1000 micromol tannic acid l(-1) during 3 h co-incubation. These results indicate that tannic acid inhibited the activity of both acrosin and plasminogen activator and indicates a possible mechanism by which flavonoids exert their antifertility effects.

A Role for Plasma Urokinase Plasminogen Activator Receptor (uPAR) in Thrombosis in Paroxysmal Nocturnal Hemoglobinuria (PNH).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 281-281
Author(s):  
Elaine M. Sloand ◽  
Lori Mainwaring ◽  
Elaine Wong ◽  
Yong Tang ◽  
McDonald K. Horne ◽  
...  
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Thrombotic Event ◽  
Urokinase Plasminogen Activator ◽  
Single Chain ◽  
Urokinase Plasminogen Activator Receptor ◽  
Cd34 Cells ◽  
History Of ◽  
Plasminogen Activator Receptor

Abstract Venous thrombotic events are responsible for serious morbidity and the most frequent cause of death in patients with paroxysmal nocturnal hemoglobinuia (PNH). Urokinase plasminogen activator receptor (uPAR) is a glycosylphosphatidylinositol (GPI)-linked protein which is expressed on neutrophils and endothelial cells and mediates endogenous thrombolysis through a urokinase plasminogen activator (uPA)-dependent mechanism. On the cell surface, pro-uPA binds to uPAR via its growth factor domain, promoting the conversion of pro-uPA to active uPA. Active uPA in turn cleaves the proenzyme plasminogen, yielding active plasmin. Previous work in PNH patients has shown that the membrane form of uPAR is decreased or absent on granulocytes, and soluble uPAR levels are increased in patient’s plasma. In the current study of 45 patients with PNH and 20 normal controls, we demonstrate that plasma suPAR concentrations correlated directly with the proportion of neutrophils lacking CD16, another GPI-anchored protein (R2=0.9), and that levels are 4-10-fold greater in PNH than in controls. Patients with a history of thrombosis had higher soluble uPAR levels (in stored samples pre-dating the thrombotic event) than did patients without a history of thrombosis (mean 2.2 ng/mL compared to 0.5 ng/mL; p=0.0001). suPAR levels returned to normal in all of five patients undergoing successful bone marrow transplantation. In normal persons soluble uPAR may be generated by alternative splicing or proteolytic cleavage. In vitro we demonstrated release of suPAR from PNH hematopoietic cells: supernatants obtained from PNH CD34 cells cultured in liquid media with standard growth factor in three experiments showed suPAR levels 20 fold greater than those obtained from normal CD34 cells. Platelets also appeared to be a substantial source of suPAR: uPAR was expressed on the surface of ADP-activated CD59-positive but not CD59-negative platelets from PNH patients. By an ELISA specific for suPAR and by immunoblot, we showed that substantial quantities of suPAR were released following collagen-activation of PNH but not normal platelets. Plasma from PNH patients contained much greater quantitites of suPAR than did peripheral blood cells from those patients. Theoretically, suPAR might bind to plasma uPA, preventing its interaction with the active membrane-anchored form. In vitro, we demonstrated dose-dependent decreases in the activity of single-chain urokinase following the addition of recombinant suPAR, with loss of 25% of the activity after the addition of 0.45nM suPAR. The absence of leukocyte and platelet plasma membrane associated uPAR and high levels of soluble uPAR in the circulation may be useful in predicting thrombosis and suggest mechanisms of anticoagulation in these unusual patients.

Sign in / Sign up

Export Citation Format

Share Document