Close similarity between cultured human omental mesothelial cells and endothelial cells in cytochemical markers and plasminogen activator production

1991 ◽  
Vol 27 (7) ◽  
pp. 542-548 ◽  
Author(s):  
Kimiko Takahashi ◽  
Jun-Ichi Hata ◽  
Kiyoshi Mukai ◽  
Yoshio Sawasaki
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 ◽  
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.


1991 ◽  
Vol 66 (03) ◽  
pp. 361-367 ◽  
Author(s):  
Y Latron ◽  
M C Alessi ◽  
F George ◽  
F Anfosso ◽  
P Poncelet ◽  
...  

SummaryCapillary cells represent 95% of the vascular bed, and cells from large and micro-vessels do not express identical functions. In order to study the hormonal regulation of plasminogen activator inhibitor 1 (PAI-1) secretion by human capillary cells we used epithelial cells from omental tissue (HOTMEC). As their endothelial origin is subject to controversy, we attempted to determine their characteristics by comparing them to human umbilical vein endothelial cells (HUVEC). Morphological and biological criteria were studied. By phase contrast microscopy HOTMEC elicited a cobblestone pattern similar to HUVEC. Weibel-Palade bodies were not found in the cytoplasm with electron microscopy. Fluorescence microscopy studies indicated that HOTMEC took up acetylated-LDL more intensely than HUVEC, and showed no staining for von Willebrand factor. The phenotype of HOTMEC was studied by flow cytometry using monoclonal antibodies (mo Ab) directed against epitopes either specific for endothelial cells or for mesothelial cells. We showed that in our preparations only 10% of cells reacted with mo Ab specific for endothelial cells. About 60% of the HOTMEC were labelled with an antibody directed against mesothelial cells. HOTMEC expressed fibrinolytic factors. Tissue plasminogen activator (t-PA) levels in HOTMEC conditioned medium were 50 fold higher than those of HUVEC, and the PAI-1 secretions were identical in both cell types. Insulin which is known to increase PAI-1 synthesis by hepatocytes did not enhance the PAI-1 level either in HOTMEC or in HUVEC conditioned media. Our results suggested that morphological and functional methods did not allow discrimination between the cell types present in the omentum tissue. They also showed that the population obtained from the omental tissue by collagenase digestion is heterogeneous, with few cells expressing endothelial markers.


1999 ◽  
Vol 82 (11) ◽  
pp. 1497-1503 ◽  
Author(s):  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Haruchika Masuda ◽  
Yasushi Kunieda ◽  
Hidehiko Kawano ◽  
...  

SummaryIn the present study, we demonstrate that brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) interact with angiotensin II (Ang II) in regulative blood coagulation and fibrinolysis by suppressing the expressions of both tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) induced by Ang II. The expressions of TF and PAI-1 mRNA were analyzed by northern blotting methods, and the activities of TF on the surface of rat aortic endothelial cells (RAECs) and PAI-1 in the culture media were respectively measured by chromogenic assay.Both BNP and CNP suppressed the expressions of TF and PAI-1 mRNA induced by Ang II in a time- and concentration-dependent manner via cGMP cascade, which suppressions were accompanied by respective decrease in activities of TF and PAI-1. However, neither the expression of tissue factor pathway inhibitor (TFPI) nor tissue-type plasminogen activator (TPA) mRNA was affected by the treatment of BNP and CNP.


1989 ◽  
Vol 62 (02) ◽  
pp. 699-703 ◽  
Author(s):  
Rob J Aerts ◽  
Karin Gillis ◽  
Hans Pannekoek

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.


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

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.


1996 ◽  
Vol 75 (06) ◽  
pp. 933-938 ◽  
Author(s):  
Marten Fålkenberg ◽  
Johan Tjärnstrom ◽  
Per Örtenwall ◽  
Michael Olausson ◽  
Bo Risberg

SummaryLocal fibrinolytic changes in atherosclerotic arteries have been suggested to influence plaque growth and promote mural thrombosis on ruptured or ulcerated plaques. Increased levels of plasminogen activator inhibitor (PAI-1) have been found in atherosclerotic arteries. In this study tissue plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA) and PAI-1 were localized in arterial biopsies of healthy and atherosclerotic vessels by immunohistochemis-try. The expression of fibrinolytic regulators was related to the distribution of endothelial cells (EC) and macrophages. Results: t-PA was expressed in vasa vasorum. PAI-1 was positive in endothelial cells, in the media and in the adventitia. Increased expression of t-PA, u-PA and PAI-1 was found in atherosclerotic vessels. t-PA, u-PA, PAI-1 and macrophages were co-localized in plaques. These results support the concept that macrophages can be important in the local regulation of fibrinolysis in atherosclerotic vessels.


1994 ◽  
Vol 72 (01) ◽  
pp. 044-053 ◽  
Author(s):  
N Chomiki ◽  
M Henry ◽  
M C Alessi ◽  
F Anfosso ◽  
I Juhan-Vague

SummaryIndividuals with elevated levels of plasminogen activator inhibitor type 1 are at risk of developing atherosclerosis. The mechanisms leading to increased plasma PAI-1 concentrations are not well understood. The link observed between increased PAI-1 levels and insulin resistance has lead workers to investigate the effects of insulin or triglyceride rich lipoproteins on PAI-1 production by cultured hepatocytes or endothelial cells. However, little is known about the contribution of these cells to PAI-1 production in vivo. We have studied the expression of PAI-1 in human liver sections as well as in vessel walls from different territories, by immunocytochemistry and in situ hybridization.We have observed that normal liver endothelial cells expressed PAI-1 while parenchymal cells did not. However, this fact does not refute the role of parenchymal liver cells in pathological states.In healthy vessels, PAI-1 mRNA and protein were detected primarily at the endothelium from the lumen as well as from the vasa vasorum. In normal arteries, smooth muscle cells were able to produce PAI-1 depending on the territory tested. In deeply altered vessels, PAI-1 expression was observed in neovessels scattering the lesions, in some intimal cells and in smooth muscle cells. Local increase PAI-1 mRNA described in atherosclerotic lesions could be due to the abundant neovascularization present in the lesion as well as a raised expression in smooth muscle cells. The increased PAI-1 in atherosclerosis could lead to fibrin deposit during plaque rupture contributing further to the development and progression of the lesion.


1986 ◽  
Vol 56 (02) ◽  
pp. 115-119 ◽  
Author(s):  
Eugene G Levin ◽  
David M Stern ◽  
Peter P Nawroth ◽  
Richard A Marlar ◽  
Daryl S Fair ◽  
...  

SummaryThe addition of thrombin (9 nM) to primary cultures of human endothelial cells induces a 6- to 7-fold increase in the rate of release of tissue plasminogen activator (tPA). Several other serine proteases which specifically interact with endothelial cells were also analyzed for their effect on tPA release. Gamma-thrombin, an autocatalytic product of α-thrombin, promoted tPA release but was less effective than α-thrombin. A maximum increase of 5.5-fold was observed, although a concentration of γ-thrombin 20 times greater than α-thrombin was required. The response to Factor Xa was similar to α-thrombin, although the stimulation was significantly reduced by the addition of hirudin or DAPA suggesting that prothrombin activation was occurring. The simultaneous addition of prothrombin with Factor Xa resulted in enhanced tPA release equal to that observed with an equimolar concentration of active α-thrombin. Thus, under these conditions, Factor Xa-cell surface mediated activation of prothrombin can lead to a secondary effect resulting from cell-thrombin interaction. Activated protein C, which has been implicated as a profibrinolytic agent, was also tested. No change in tPA release occurred after the addition of up to 325 nM activated protein C in the presence or absence of proteins. Factor IXa and plasmin were also ineffective. The effect of thrombin on the endothelial cell derived plasminogen activator specific inhibitor was also studied. Thrombin produced a small but variable release of the inhibitor with an increase of less than twice that of non-thrombin treated controls.


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