Time course of recovery of endothelial cell surface thrombin receptor (PAR-1) expression

1999 ◽  
Vol 276 (1) ◽  
pp. C38-C45 ◽  
Author(s):  
Chad A. Ellis ◽  
Chinnaswamy Tiruppathi ◽  
Raudel Sandoval ◽  
Walter D. Niles ◽  
Asrar B. Malik

We studied dynamics of cell surface expression of proteolytically activated thrombin receptor (PAR-1) in human pulmonary artery endothelial cells (HPAEC). PAR-1 activation was measured by changes in cytosolic calcium concentration ([Ca2+]i) and HPAEC retraction response (determined by real-time transendothelial monolayer electrical resistance). [Ca2+]iincrease in response to thrombin was abolished by preexposure to 25 nM thrombin for >60 min, indicating PAR-1 desensitization, but preexposure to 25 nM thrombin for only 30 min or to 10 nM thrombin for up to 2 h did not desensitize PAR-1. Exposure to 10 or 25 nM thrombin decreased monolayer electrical resistance 40–60%. Cells preexposed to 10 nM thrombin, but not those preexposed to 25 nM thrombin, remained responsive to thrombin 3 h later. Loss of cell retractility was coupled to decreased cell surface PAR-1 expression as determined by immunofluorescence. Cell surface PAR-1 disappeared upon short-term (30 min) thrombin exposure but reappeared within 90 min after incubation in thrombin-free medium. Exposure to 25 nM thrombin for >60 min prevented rapid cycloheximide-insensitive PAR-1 reappearance. Cycloheximide-sensitive recovery of cell surface PAR-1 expression required 18 h. Therefore, both duration and concentration of thrombin exposure regulate the time course of recovery of HPAEC surface PAR-1 expression. The results support the hypothesis that initial recovery of PAR-1 surface expression in endothelial cells results from a rapidly mobilizable PAR-1 pool, whereas delayed recovery results from de novo PAR-1 synthesis. We conclude that thrombin itself regulates endothelial cell surface PAR-1 expression and that decreased surface expression interferes with thrombin-induced endothelial cell activation responses.

1998 ◽  
Vol 274 (2) ◽  
pp. C387-C395 ◽  
Author(s):  
Weihong Yan ◽  
Chinnaswamy Tiruppathi ◽  
Hazel Lum ◽  
Renli Qiao ◽  
Asrar B. Malik

We studied the effects of protein kinase C (PKC) activation on endothelial cell surface expression and function of the proteolytically activated thrombin receptor 1 (PAR-1). Cell surface PAR-1 expression was assessed by immunofluorescence (using anti-PAR-1 monoclonal antibody), and receptor activation was assessed by measuring increases in cytosolic Ca2+ concentration in human dermal microvascular endothelial cells (HMEC) exposed to α-thrombin or phorbol ester, 12- O-tetradecanoylphorbol-13-acetate (TPA). Immunofluorescence showed that thrombin and TPA reduced the cell surface expression of PAR-1. Prior exposure of HMEC to thrombin for 5 min desensitized the cells to thrombin, indicating homologous PAR-1 desensitization. In contrast, prior activation of PKC with TPA produced desensitization to thrombin and histamine, indicating heterologous PAR-1 desensitization. Treatment of cells with staurosporine, a PKC inhibitor, fully prevented heterologous desensitization, whereas thrombin-induced homologous desensitization persisted. Depletion of PKCβ isozymes (PKCβI and PKCβII) by transducing cells with antisense cDNA of PKCβIprevented the TPA-induced decrease in cell surface PAR-1 expression and restored ∼60% of the cytosolic Ca2+ signal in response to thrombin. In contrast, depletion of PKCβ isozymes did not affect the loss of cell surface PAR-1 and induction of homologous PAR-1 desensitization by thrombin. Therefore, homologous PAR-1 desensitization by thrombin occurs independently of PKCβ isozymes, whereas the PKCβ-activated pathway is important in signaling heterologous PAR-1 desensitization in endothelial cells.


2008 ◽  
Vol 15 (2) ◽  
pp. 136-144 ◽  
Author(s):  
Benjamin G. Lilienfeld ◽  
Anita Schildknecht ◽  
Lukas L. Imbach ◽  
Nicolas J. Mueller ◽  
Mårten K. J. Schneider ◽  
...  

Blood ◽  
2013 ◽  
Vol 122 (14) ◽  
pp. 2491-2499 ◽  
Author(s):  
Elzbieta Pluskota ◽  
Yi Ma ◽  
Kamila M. Bledzka ◽  
Katarzyna Bialkowska ◽  
Dmitry A. Soloviev ◽  
...  

Key Points Kindlin-2 regulates hemostasis in vivo by limiting CD39 and CD73 expression on the surface of endothelial cells. Kindlin-2 interacts directly with CHC and controls clathrin-dependent CD39 and CD73 endocytosis/recycling in endothelial cells.


2021 ◽  
Author(s):  
Joanne T. deKay ◽  
Joshua Carver ◽  
Bailey Shevenell ◽  
Angela M. Kosta ◽  
Sergey Tsibulnikov ◽  
...  

Abstract Background We investigated the cell surface expression of ErbB receptors on left ventricular (LV) epicardial endothelial cells and CD105+ cells obtained from cardiac biopsies of patients undergoing coronary artery bypass grafting surgery (CABG). Methods Endothelial cells and CD105+ non-endothelial cells were freshly isolated from LV epicardial biopsies obtained from 15 subjects with diabetes mellitus (DM) and 8 controls. The expression of ErbB recepotrs was examined using multiparametric flow cytometry. Human microvascular endothelial cells (HMEC-1) and LV epicardial CD105+ non-endothelial cells were used to determine the effect of high glucose on ADAM10-dependent cleavage of ErbB receptors. Results We found that diabetes mellitus (DM) and high levels of hemoglobin A1C are associated with reduced expression of ErbB2 on both endothelial cells and CD105+ non-endothelial cells. To determine if the expression of ErbB2 receptors is regulated by glucose levels, we examined the effect of high glucose in HMEC-1 and LV epicardial CD105+ non-endothelial cells, using a novel flow cytometric approach to simultaneously determine the total level, cell surface expression, and phosphorylation of ErbB2. Incubation of cells in the presence of 25 mM D-glucose resulted in decreased cell surface expression of ErbB2. We also found high expression of a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) on both endothelial cells and CD105+ non-endothelial cells. Inhibition of ADAM10 prevented the high glucose-dependent decrease in the cell surface expression of ErbB2. Conclusions We suggest that high glucose depresses ErbB receptor signaling in endothelial cells and cardiac progenitor cells via the promotion of ADAM10-dependent cleavage of ErbB2 at the cell surface, thus contributing to vascular dysfunction and adverse remodeling seen in diabetic patients.


1987 ◽  
Author(s):  
Freek van Iwaarden ◽  
G Philip ◽  
de Groot ◽  
Bonno N Bouma

The presence of High Molecular Weight kininogen (HMWK) was demonstrated in cultured human endothelial cells (EC) by immunofluorescence techniques. Using an enzyme linked immunosorbent assay a concentration of 58 ng HMWK/10 cells was determined. Immunoprecipitation studies performed with lysed metabolically labelled endothelial cells and mono-specific antisera directed against HMWK suggested that HMWK is not synthesized by the endothelial cells. Endothelial cells cultured in the presence of HMWK-depleted serum did not contain HMWK. This, suggests that endothelial cells can internalize HMWK. Using 125I-HMWK it was demonstrated that cultured endothelial cells bind HMWK in a time-dependent, specific and saturable.way. The cells were found to internalize 125I-HMWK, since I-HMWK was detected in solubilized endothelial cells after the cell bound 125I-HMWK had been eluted with dextran sulphate.The binding of I-HMWK required the presence of zinc ions. Optimal binding of 125I-HMWK was observed at 50 μM Zn++ . Calcium ions inhibited the Zn++ dependent binding of 125I-HMWK |25EC. In the presence of 3 mM CaCl2 the total binding of 125I-HMWK was significantly decreased, and a .concentration of 200 μM Zn++ was Required for the binding of 125I-HMWK to thecells. Higher,. Ca concentrations did not further decrease the binding of 125I-HMWK. Analysis of tl^e binding data by the ligand computer program indicated 3.2 x 10 binding sites per cell for HMWK with a Kd of 35 nM at 50 μM ZnCl2 and 1 mM CaCl2. Specify binding of HMWK did also occur at physiological plasma Zn++ concentrations. Half maximal binding was observed at HMWK concentrations of ± 105 nM at 10 μM ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 pM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway. M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway. M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway. M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 10 molecules of HMWK bound per cell and at 80 nM with 2.8 x 10 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway.M ZnCl2 and 45 nM at 25 μM ZnCl2. The HMWK binding sites were saturatecT at HMWK concentrations of 130 nM with 1.6 x 16 molecules of HMWK bound per cell and at 80 nM with 2.8 x 106 molecules of HMWK bound per cell at 10 and 25 μM ZnCl2 respectively. These results suggest that at physiological zinc, calcium and HMWK concentrations the HMWK binding sites on the endothelial cell are saturated. The presence of HMWK on the endothelial cell surface may play a role in the initiation of the intrinsic coagulation pathway.


2013 ◽  
Vol 109 (06) ◽  
pp. 1070-1078 ◽  
Author(s):  
Zhanyang Yu ◽  
Xiang Fan ◽  
Ning Liu ◽  
Min Yan ◽  
Zhong Chen ◽  
...  

SummaryHyperglycaemia impairs fibrinolytic activity on the surface of endothelial cells, but the underlying mechanisms are not fully understood. In this study, we tested the hypothesis that hyperglycaemia causes dysfunction of the endothelial membrane protein annexin A2, thereby leading to an overall reduction of fibrinolytic activity. Hyperglycaemia for 7 days significantly reduced cell surface fibrinolytic activity in human brain microvascular endothelial cells (HBMEC). Hyperglycaemia also decreased tissue type plasminogen activator (t-PA), plasminogen, and annexin A2 mRNA and protein expression, while increasing plasminogen activator inhibitor-1 (PAI-1). No changes in p11 mRNA or protein expression were detected. Hyperglycaemia significantly increased AGE-modified forms of total cellular and membrane annexin A2. The hyperglycemia-associated reduction in fibrinolytic activity was fully restored upon incubation with recombinant annexin A2 (rA2), but not AGE-modified annexin A2 or exogenous t-PA. Hyperglycaemia decreased t-PA, upregulated PAI-1 and induced AGE-related disruption of annexin A2 function, all of which contributed to the overall reduction in endothelial cell surface fibrinolytic activity. Further investigations to elucidate the underlying molecular mechanisms and pathophysiological implications of A2 derivatisation might ultimately lead to a better understanding of mechanisms of impaired vascular fibrinolysis, and to development of new interventional strategies for the thrombotic vascular complications in diabetes.


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