scholarly journals Characterization and fibrinolytic properties of human omental tissue mesothelial cells. Comparison with endothelial cells

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1490-1497 ◽  
Author(s):  
VW van Hinsbergh ◽  
T Kooistra ◽  
MA Scheffer ◽  
J Hajo van Bockel ◽  
GN van Muijen

Abstract It has been reported that omental fat tissue is a good source of human microvascular endothelial cells. By characterization we demonstrate that the epitheloid cells isolated from omental tissue are not endothelial cells, but mesothelial cells. They contain abundant cytokeratins 8 and 18, which are absent in endothelial cells, and vimentin. No staining with the endothelial-specific antibodies EN-4 and PAL-E is observed. A faint and diffuse staining of von Willebrand factor (vWF) is seen in mesothelial cells, whereas microvascular endothelial cells from subcutaneous fat display vWF in distinct granular structures. Human peritoneal mesothelium produces plasminogen activator-dependent fibrinolytic activity, which is essential in the resolution of fibrous exudates and may therefore be important in preventing the formation of fibrous peritoneal adhesions. This fibrinolytic activity is plasminogen activator-dependent, but has not been fully characterized. We report here that human omental tissue mesothelial cells in vitro produce large amounts of tissue-type plasminogen activator (t-PA), together with type 1 and 2 plasminogen activator inhibitor (PAI-1 and PAI-2). PAI-1 is predominantly secreted into the culture medium, whereas the major part of PAI-2 is found in the cells. No urokinase-type plasminogen activator is detected. On stimulation with the inflammatory mediator tumor necrosis factor (TNF), at least a threefold decrease in t-PA antigen is observed, together with an increase in both PAI-1 and PAI-2. TNF also induces a marked change in cell shape. Whereas TNF and bacterial lipopolysaccharide (LPS) have similar effects on the production of PA inhibitor by human endothelial cells, LPS has no or only a relatively small effect on the fibrinolytic properties of mesothelial cells. The decreased fibrinolytic activity induced by the cytokine TNF may impair the natural dissolution of fibrin deposits at the peritoneum in the presence of an inflammatory reaction.

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1490-1497
Author(s):  
VW van Hinsbergh ◽  
T Kooistra ◽  
MA Scheffer ◽  
J Hajo van Bockel ◽  
GN van Muijen

It has been reported that omental fat tissue is a good source of human microvascular endothelial cells. By characterization we demonstrate that the epitheloid cells isolated from omental tissue are not endothelial cells, but mesothelial cells. They contain abundant cytokeratins 8 and 18, which are absent in endothelial cells, and vimentin. No staining with the endothelial-specific antibodies EN-4 and PAL-E is observed. A faint and diffuse staining of von Willebrand factor (vWF) is seen in mesothelial cells, whereas microvascular endothelial cells from subcutaneous fat display vWF in distinct granular structures. Human peritoneal mesothelium produces plasminogen activator-dependent fibrinolytic activity, which is essential in the resolution of fibrous exudates and may therefore be important in preventing the formation of fibrous peritoneal adhesions. This fibrinolytic activity is plasminogen activator-dependent, but has not been fully characterized. We report here that human omental tissue mesothelial cells in vitro produce large amounts of tissue-type plasminogen activator (t-PA), together with type 1 and 2 plasminogen activator inhibitor (PAI-1 and PAI-2). PAI-1 is predominantly secreted into the culture medium, whereas the major part of PAI-2 is found in the cells. No urokinase-type plasminogen activator is detected. On stimulation with the inflammatory mediator tumor necrosis factor (TNF), at least a threefold decrease in t-PA antigen is observed, together with an increase in both PAI-1 and PAI-2. TNF also induces a marked change in cell shape. Whereas TNF and bacterial lipopolysaccharide (LPS) have similar effects on the production of PA inhibitor by human endothelial cells, LPS has no or only a relatively small effect on the fibrinolytic properties of mesothelial cells. The decreased fibrinolytic activity induced by the cytokine TNF may impair the natural dissolution of fibrin deposits at the peritoneum in the presence of an inflammatory reaction.


Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3285-3292 ◽  
Author(s):  
J Wojta ◽  
M Gallicchio ◽  
H Zoellner ◽  
EL Filonzi ◽  
JA Hamilton ◽  
...  

Abstract The effect of interleukin-4 (IL-4) on the fibrinolytic system of human microvascular and macrovascular endothelial cells in culture was studied. Only foreskin microvascular endothelial cells (EC) responded to IL-4 treatment with a dose- and time-dependent increase in urokinase- type plasminogen activator (u-PA) (control: 3.0 +/- 0.8 ng/10(5) cells/24 h; 200 U/mL IL-4: 6.7 +/- 0.8 ng/10(5) cells/24 h), whereas human macrovascular EC remained unaffected. A maximum effect was achieved with 200 U/mL IL-4. Little u-PA activity was detected in the conditioned media of human foreskin microvascular EC (HFMEC) treated without and with IL-4 before plasmin treatment (control: 0.03 +/- 0.003 IU/10(5) cells/20 h; 200 U/mL IL-4: 0.09 +/- 0.007 IU/10(5) cells/20 h). These values increased to 0.18 +/- 0.02 IU/10(5) cells/20 h and 0.53 +/- 0.04 IU/10(5) cells/20 h, respectively, after plasmin treatment, indicating that u-PA is released by HFMEC predominantly in its inactive precursor form single-chain u-PA (scu-PA). u-PA activity increased also in the cell lysates of HFMEC up to 2.5-fold after IL-4 treatment. Plasminogen activator inhibitor type-1 (PAI-1) levels produced by HFMEC remained unaffected by IL-4, whereas tissue-type plasminogen activator (t-PA) levels were slightly decreased when HFMEC were treated with IL-4. These findings were also reflected in the specific mRNA levels as determined by Northern blotting. u-PA-specific mRNA increased significantly in HFMEC in the presence of IL-4, whereas t-PA mRNA and PAI-1-specific mRNA in HFMEC and u-PA specific mRNA in human saphenous vein EC (HSVEC) remained unaffected by IL-4 treatment. Our findings suggest a role for IL-4 in the process of angiogenesis, in addition to its known proliferative effect on human microvascular EC, by increasing the fibrinolytic potential of such EC, thereby facilitating extracellular proteolysis and cell migration.


Blood ◽  
1993 ◽  
Vol 81 (12) ◽  
pp. 3285-3292 ◽  
Author(s):  
J Wojta ◽  
M Gallicchio ◽  
H Zoellner ◽  
EL Filonzi ◽  
JA Hamilton ◽  
...  

The effect of interleukin-4 (IL-4) on the fibrinolytic system of human microvascular and macrovascular endothelial cells in culture was studied. Only foreskin microvascular endothelial cells (EC) responded to IL-4 treatment with a dose- and time-dependent increase in urokinase- type plasminogen activator (u-PA) (control: 3.0 +/- 0.8 ng/10(5) cells/24 h; 200 U/mL IL-4: 6.7 +/- 0.8 ng/10(5) cells/24 h), whereas human macrovascular EC remained unaffected. A maximum effect was achieved with 200 U/mL IL-4. Little u-PA activity was detected in the conditioned media of human foreskin microvascular EC (HFMEC) treated without and with IL-4 before plasmin treatment (control: 0.03 +/- 0.003 IU/10(5) cells/20 h; 200 U/mL IL-4: 0.09 +/- 0.007 IU/10(5) cells/20 h). These values increased to 0.18 +/- 0.02 IU/10(5) cells/20 h and 0.53 +/- 0.04 IU/10(5) cells/20 h, respectively, after plasmin treatment, indicating that u-PA is released by HFMEC predominantly in its inactive precursor form single-chain u-PA (scu-PA). u-PA activity increased also in the cell lysates of HFMEC up to 2.5-fold after IL-4 treatment. Plasminogen activator inhibitor type-1 (PAI-1) levels produced by HFMEC remained unaffected by IL-4, whereas tissue-type plasminogen activator (t-PA) levels were slightly decreased when HFMEC were treated with IL-4. These findings were also reflected in the specific mRNA levels as determined by Northern blotting. u-PA-specific mRNA increased significantly in HFMEC in the presence of IL-4, whereas t-PA mRNA and PAI-1-specific mRNA in HFMEC and u-PA specific mRNA in human saphenous vein EC (HSVEC) remained unaffected by IL-4 treatment. Our findings suggest a role for IL-4 in the process of angiogenesis, in addition to its known proliferative effect on human microvascular EC, by increasing the fibrinolytic potential of such EC, thereby facilitating extracellular proteolysis and cell migration.


2007 ◽  
Vol 97 (02) ◽  
pp. 263-271 ◽  
Author(s):  
James Muldowney III ◽  
Corrie Painter ◽  
Elaine Sanders-Bush ◽  
Nancy Brown ◽  
Douglas Vaughan

SummaryThe acute physiologic release of tissue-type plasminogen activator (t-PA) from the endothelium is critical for vascular homeostasis. This process is prostacyclin- and nitric oxide (NO)-independent in humans. It has been suggested that calcium signaling and endothelial-derived hyperpolarizing factors (EDHF) may play a role in t-PA release. G-protein-coupled receptor-dependent calcium signaling is typically Gαq -dependent. EDHFs have been functionally defined and in various tissues are believed to be various regioisomers of the epoxyeicosatrienoic acids (EETs). We tested the hypothesis in vitrothat thrombin-stimulated t-PA release from human microvascular endothelial cells (HMECs) is both Gαq - and EDHF-dependent. Conditioned media was harvested following thrombin stimulation, and t-PA antigen was measured by ELISA. Thrombin-induced t-PA release was limited by a membrane-permeable Gαq inhibitory peptide, the PLC-β antagonist U73122, and the IP3 receptor antagonist 2-aminoethoxyphenylborane, while the Gαq agonist Pasteurellatoxin modestly induced t-PA release. The cytochrome P450 (CYP450) inhibitor, miconazole, and the arachidonic acid epoxygenase inhibitor MS-PPOH inhibited thrombin-stimulated t-PA release, while 5,6-EET-methyl ester stimulated t-PA release. The 5,6- and 14,15-EET antagonist, 14,15-epoxyeicosa-5(Z)- enoic acid, inhibited t-PA release at the 100 µM concentration. However, thrombin-stimulated t-PA release was unaffected by the prostacyclin and NO inhibitors ASA and L-NAME, as well as the potassium channel inhibitors TEA, apamin and charybdotoxin. These studies suggest that thrombin-stimulated t-PA release is Gαq-, PLC-β -, IP3 -, and 5,6-EET-dependent while being prostacyclin-, NO- and K + channel-independent in HMECs.


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Qi Liu ◽  
Xiang Fan ◽  
Helen Brogren ◽  
Ming-Ming Ning ◽  
Eng H Lo ◽  
...  

Aims: Plasminogen activator inhibitor-1 (PAI-1) is the main and potent endogenous tissue-type plasminogen activator (tPA) inhibitor, but an important question on whether PAI-1 in blood stream responds and interferes with the exogenously administered tPA remains unexplored. We for the first time investigated temporal profiles of PAI-1 concentration and activity in circulation after stroke and tPA administration in rats. Methods: Permanent MCAO focal stroke of rats were treated with saline or 10mg/kg tPA at 3 hours after stroke (n=10 per group). Plasma (platelet free) PAI-1 antigen and activity levels were measured by ELISA at before stroke, 3, 4.5 (1.5 hours after saline or tPA treatments) and 24 hours after stroke. Since vascular endothelial cells and platelets are two major cellular sources for PAI-1 in circulation, we measured releases of PAI-1 from cultured endothelial cells and isolated platelets after direct tPA (4 μg/ml) exposures for 60 min in vitro by ELISA (n=4 per group). Results: At 3 hours after stroke, both plasma PAI-1 antigen and activity were significantly increased (3.09±0.67, and 3.42±0.57 fold of before stroke baseline, respectively, all data are expressed as mean±SE). At 4.5 hours after stroke, intravenous tPA administration significantly further elevated PAI-1 antigen levels (5.26±1.24), while as expected that tPA neutralized most elevated PAI-1 activity (0.33±0.05). At 24 hours after stroke, PAI-1 antigen levels returned to the before baseline level, however, there was a significantly higher PAI-1 activity (2.51±0.53) in tPA treated rats. In vitro tPA exposures significantly increased PAI-1 releases into culture medium in cultured endothelial cells (1.65±0.08) and platelets (2.02±0.17). Conclution: Our experimental results suggest that tPA administration may further elevate stroke-increased blood PAI-1 concentration, but also increase PAI-1 activity at late 24 hours after stroke. The increased PAI-1 releases after tPA exposures in vitro suggest tPA may directly stimulate PAI-1 secretions from vascular walls and circulation platelets, which partially contributes to the PAI-1 elevation observed in focal stroke rats. The underlying regulation mechanisms and pathological consequence need further investigation.


1998 ◽  
Vol 275 (1) ◽  
pp. L47-L54 ◽  
Author(s):  
Kimiko Takahashi ◽  
Yasuhide Uwabe ◽  
Yoshio Sawasaki ◽  
Toshio Kiguchi ◽  
Hiroyuki Nakamura ◽  
...  

Human lung microvascular endothelial cells (HLMECs) secreted 1.5–15 times more urokinase-type plasminogen activator (uPA) antigen than human hepatic microvascular endothelial cells, human umbilical vein endothelial cells (HUVECs), angioma endothelial cells, and lung fibroblasts. All of these cells also secreted a 100-fold greater amount of plasminogen activator inhibitor-1 than of uPA antigen, and uPA activities were not detected in the culture medium. The expression of uPA mRNA in HLMECs was higher (100-fold) compared with HUVECs, angioma endothelial cells, and lung fibroblasts. HLMECs secreted uPA antigen on both the luminal and basal sides of the cells. On the other hand, HLMECs secreted a 10- to 15-fold lower amount of tissue-type plasminogen activator than HUVECs, mostly on the luminal side. After stimulation with interleukin (IL)-1β, HLMECs secreted a six- to ninefold amount of uPA antigen. In contrast, no stimulatory effect was observed in HUVECs even under high IL-1β concentrations. The secretion of uPA and plasminogen activator inhibitor-1 from HLMECs was also enhanced by tumor necrosis factor-α and IL-2. These results suggest that HLMECs may contribute not only to the patency of lung vessels but also to the maintenance of alveolar functions through the production and secretion of uPA, especially in the presence of inflammatory cytokines.


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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