scholarly journals Transforming growth factor-beta 1 modulates basic fibroblast growth factor-induced proteolytic and angiogenic properties of endothelial cells in vitro.

1990 ◽  
Vol 111 (2) ◽  
pp. 743-755 ◽  
Author(s):  
M S Pepper ◽  
D Belin ◽  
R Montesano ◽  
L Orci ◽  
J D Vassalli
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Lumen Formation ◽  
Growth Factor Beta ◽  
Pai 1

Tightly controlled proteolytic degradation of the extracellular matrix by invading microvascular endothelial cells is believed to be a necessary component of the angiogenic process. We have previously demonstrated the induction of plasminogen activators (PAs) in bovine microvascular endothelial (BME) cells by three agents that induce angiogenesis in vitro: basic FGF (bFGF), PMA, and sodium orthovanadate. Surprisingly, we find that these agents also induce plasminogen activator inhibitor-1 (PAI-1) activity and mRNA in BME cells. We also find that transforming growth factor-beta 1 (TGF-beta 1), which in vitro modulates a number of endothelial cell functions relevant to angiogenesis, also increases both PAI-1 and urokinase-type PA (u-PA) mRNA. Thus, production of both proteases and protease inhibitors is increased by angiogenic agents and TGF-beta 1. However, the kinetics and amplitude of PAI-1 and u-PA mRNA induction by these agents are strikingly different. We have used the ratio of u-PA:PAI-1 mRNA levels as an indicator of proteolytic balance. This ratio is tilted towards enhanced proteolysis in response to bFGF, towards antiproteolysis in response to TGF-beta 1, and is similar to that in untreated cultures when the two agents are added simultaneously. Using an in vitro angiogenesis assay in three-dimensional fibrin gels, we find that TGF-beta 1 inhibits the bFGF-induced formation of tube-like structures, resulting in the formation of solid endothelial cell cords within the superficial parts of the gel. These results suggest that a net positive proteolytic balance is required for capillary lumen formation. A novel perspective is provided on the relationship between extracellular matrix invasion, lumen formation, and net proteolytic balance, thereby reflecting the interplay between angiogenesis-modulating cytokines such as bFGF and TGF-beta 1.

scholarly journals Platelets stimulate endothelial cells to synthesize type 1 plasminogen activator inhibitor. Evaluation of the role of transforming growth factor beta

Blood ◽  
1991 ◽  
Vol 77 (5) ◽  
pp. 1013-1019 ◽  
Author(s):  
SR Slivka ◽  
DJ Loskutoff
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Plasminogen Activator Inhibitor ◽  
Tgf Beta ◽  
Growth Factor Beta ◽  
Activator Inhibitor ◽  
Pai 1

Abstract A model system consisting of thrombin-stimulated bovine platelet releasates (PRthr) and bovine aortic endothelial cells (BAEs) was developed to determine if the interaction between platelets and endothelial cells regulates fibrinolysis. Zymographic analysis indicated that PRthr treatment of BAEs decreases urokinase and increases type 1 plasminogen activator inhibitor (PAI-1) activity. Although PRthr did not affect the overall rate of BAE protein synthesis, it increased PAI-1 biosynthesis within 6 hours. This increase was complete by 12 hours, with maximum stimulation at 10 to 15 micrograms/mL PRthr (1 microgram approximately 10(7) platelets). Neutralizing antibodies to transforming growth factor beta (TGF beta) reduced this effect by 75%. Treatments that activate latent TGF beta (eg, acidification or plasmin) increased this effect approximately fivefold, suggesting that TGF beta in PRthr exists in both a latent (approximately 80%) and an active (approximately 20%) form. In contrast to PRthr, adenosine diphosphate-prepared platelet releasates did not increase PAI-1 synthesis before acidification, indicating that they contain only the latent form of TGF beta. These results suggest that platelets can modulate the fibrinolytic system of the endothelium through the release of TGF beta, and that the mechanism by which the platelets are activated can influence the relative amount of active TGF beta.

scholarly journals Platelets stimulate endothelial cells to synthesize type 1 plasminogen activator inhibitor. Evaluation of the role of transforming growth factor beta

Blood ◽  
1991 ◽  
Vol 77 (5) ◽  
pp. 1013-1019 ◽  
Author(s):  
SR Slivka ◽  
DJ Loskutoff
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Plasminogen Activator Inhibitor ◽  
Tgf Beta ◽  
Growth Factor Beta ◽  
Activator Inhibitor ◽  
Pai 1

A model system consisting of thrombin-stimulated bovine platelet releasates (PRthr) and bovine aortic endothelial cells (BAEs) was developed to determine if the interaction between platelets and endothelial cells regulates fibrinolysis. Zymographic analysis indicated that PRthr treatment of BAEs decreases urokinase and increases type 1 plasminogen activator inhibitor (PAI-1) activity. Although PRthr did not affect the overall rate of BAE protein synthesis, it increased PAI-1 biosynthesis within 6 hours. This increase was complete by 12 hours, with maximum stimulation at 10 to 15 micrograms/mL PRthr (1 microgram approximately 10(7) platelets). Neutralizing antibodies to transforming growth factor beta (TGF beta) reduced this effect by 75%. Treatments that activate latent TGF beta (eg, acidification or plasmin) increased this effect approximately fivefold, suggesting that TGF beta in PRthr exists in both a latent (approximately 80%) and an active (approximately 20%) form. In contrast to PRthr, adenosine diphosphate-prepared platelet releasates did not increase PAI-1 synthesis before acidification, indicating that they contain only the latent form of TGF beta. These results suggest that platelets can modulate the fibrinolytic system of the endothelium through the release of TGF beta, and that the mechanism by which the platelets are activated can influence the relative amount of active TGF beta.

scholarly journals Latent transforming growth factor-beta 1 and its binding protein are components of extracellular matrix microfibrils.

1996 ◽  
Vol 44 (8) ◽  
pp. 875-889 ◽  
Author(s):  
J Taipale ◽  
J Saharinen ◽  
K Hedman ◽  
J Keski-Oja
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Binding Protein ◽  
Human Fibroblasts ◽  
Tgf Beta ◽  
Growth Factor Beta ◽  
Cellular Fibronectin

We studied the localization of latent transforming growth factor-beta 1 (TGF-beta 1) and its binding protein (LTBP-1) in the extracellular matrix of cultured human fibroblasts by immunofluorescence and immunoelectron microscopy. Immunofluorescence of confluent fibroblast cultures indicated that LTBP-1 localizes to extracellular fibrillar structures resembling fibronectin-collagen matrix. Similar fibrillar structures were detected in cells stained with antibodies specific for TGF-beta 1 propeptide (beta 1-LAP). Both LTBP-1 and beta 1-LAP colocalized with fibronectin in double immunofluorescence analysis. These fibrillar structures were resistant to extraction with sodium deoxycholate, which is further evidence that LTBP-1 and large latent TGF-beta 1 complexes are integral components of the extracellular matrix. SV-40-transformed human fibroblasts lacked extracellular LTBP-1 fibers. EM analysis revealed approximately 10-nm-thick microfibrils that were labeled by anti-LTBP at 90-140-nm intervals. In addition, LTBP-1 was found in structures that were heavily labeled for fibronectin. The accumulation of LTBP-1 in the fibronectin matrix could be reconstituted in vitro. When isolated matrix components were immobilized on nitrocellulose and incubated with fibroblast conditioned medium, LTBP-1 from the medium associated with cellular fibronectin but not with heparan or chondroitin sulfate, vitronectin, tenascin, laminin, or collagen I or IV. The association of LTBP-1 with cellular fibronectin was abolished by treatment of the medium with plasmin, which cleaves LTBP-1 and inhibits its assembly to matrix. The present results indicate that latent TGF-beta 1 complexes are components of the extracellular matrix and suggest that alterations of the pericellular matrix could result in aberrant TGF-beta signaling.

scholarly journals Transforming growth factor beta suppresses human immunodeficiency virus expression and replication in infected cells of the monocyte/macrophage lineage.

1991 ◽  
Vol 173 (3) ◽  
pp. 589-597 ◽  
Author(s):  
G Poli ◽  
A L Kinter ◽  
J S Justement ◽  
P Bressler ◽  
J H Kehrl ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Growth Factor ◽  
Cell Line ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Immunodeficiency Virus ◽  
Growth Factor Beta

The pleiotropic immunoregulatory cytokine transforming growth factor beta (TGF-beta) potently suppresses production of the human immunodeficiency virus (HIV), the causative agent of the acquired immunodeficiency syndrome, in the chronically infected promonocytic cell line U1. TGF-beta significantly (50-90%) inhibited HIV reverse transcriptase production and synthesis of viral proteins in U1 cells stimulated with phorbol myristate acetate (PMA) or interleukin 6 (IL-6). Furthermore, TGF-beta suppressed PMA induction of HIV transcription in U1 cells. In contrast, TGF-beta did not significantly affect the expression of HIV induced by tumor necrosis factor alpha (TNF-alpha). These suppressive effects were not mediated via the induction of interferon alpha (IFN-alpha). TGF-beta also suppressed HIV replication in primary monocyte-derived macrophages infected in vitro, both in the absence of exogenous cytokines and in IL-6-stimulated cultures. In contrast, no significant effects of TGF-beta were observed in either a chronically infected T cell line (ACH-2) or in primary T cell blasts infected in vitro. Therefore, TGF-beta may play a potentially important role as a negative regulator of HIV expression in infected monocytes or tissue macrophages in infected individuals.

Early gene responses to transforming growth factor-beta in cells lacking growth-suppressive RB function

1991 ◽  
Vol 11 (10) ◽  
pp. 4952-4958
Author(s):  
A Zentella ◽  
F M Weis ◽  
D A Ralph ◽  
M Laiho ◽  
J Massagué
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Lung Epithelial Cells ◽  
Early Gene ◽  
Tgf Beta ◽  
Suppressive Function ◽  
Growth Factor Beta ◽  
Pai 1

The growth-suppressive function of the retinoblastoma susceptibility gene product, RB, has been implicated in the mediation of growth inhibition and negative regulation of certain proliferation related genes by transforming growth factor-beta 1 (TGF-beta 1). Early gene responses to TGF-beta 1 were examined in order to determine their dependence on the cell cycle and on the growth-suppressive function of RB. TGF-beta 1, which rapidly elevates the steady-state level of junB and PAI-1 mRNAs and decreases that of c-myc mRNA, induces these responses in S-phase populations of Mv1Lu lung epithelial cells containing RB in a phosphorylated state. Since in this state RB is presumed to lack growth-suppressive activity, the response to TGF-beta 1 was also examined in DU145 human prostate carcinoma cells whose mutant RB product lacks growth-suppressive function. In these cells, TGF-beta 1 also decreases c-myc expression at the transcription initiation level. These results suggests that the c-myc, junB, and PAI-1 responses to TGF-beta 1 are not restricted to the G1 phase of the cell cycle and that down-regulation of c-myc expression by TGF-beta 1 can occur through a mechanism independent from the growth-suppressive function of RB.

In vitro modulation of endothelial fenestrae: opposing effects of retinoic acid and transforming growth factor beta

1988 ◽  
Vol 91 (2) ◽  
pp. 313-318
Author(s):  
T. Lombardi ◽  
R. Montesano ◽  
M.B. Furie ◽  
S.C. Silverstein ◽  
L. Orci
Keyword(s):  
Endothelial Cells ◽  
Retinoic Acid ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Surface Density ◽  
Transforming Growth Factor ◽  
Control Cell ◽  
Tgf Beta ◽  
Growth Factor Beta

Cultured endothelial cells isolated from fenestrated capillaries express many properties characteristic of their in vivo differentiated phenotype, including the formation of a limited number of fenestrae. In this study, we have investigated whether physiological factors that control cell differentiation might regulate the surface density of fenestrae in capillary endothelial cells. We have found that treatment of the cultures with retinoic acid (10 microM) induces a more than threefold increase in the surface density of endothelial fenestrae, whereas transforming growth factor beta (TGF beta) (2 ng ml-1) causes a sevenfold decrease in the surface density of these structures. These results show that the expression of endothelial fenestrae is susceptible to bidirectional modulation by physiological signals, and suggest that retinoids and TGF beta may participate in the regulation of fenestral density of capillary endothelium in vivo.

scholarly journals Transforming growth factor beta 1 (TGF-beta 1) induced neutrophil recruitment to synovial tissues: implications for TGF-beta-driven synovial inflammation and hyperplasia.

1991 ◽  
Vol 173 (5) ◽  
pp. 1121-1132 ◽  
Author(s):  
R A Fava ◽  
N J Olsen ◽  
A E Postlethwaite ◽  
K N Broadley ◽  
J M Davidson ◽  
...  
Keyword(s):  
Growth Factor ◽  
Synovial Tissue ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Tgf Beta ◽  
Histological Techniques ◽  
Growth Factor Beta

We have studied the consequences of introducing human recombinant transforming growth factor beta 1 (hrTGF-beta 1) into synovial tissue of the rat, to begin to better understand the significance of the fact that biologically active TGF-beta is found in human arthritic synovial effusions. Within 4-6 h after the intra-articular injection of 1 microgram of hrTGF-beta 1 into rat knee joints, extensive recruitment of polymorphonuclear leukocytes (PMNs) was observed. Cytochemistry and high resolution histological techniques were used to quantitate the influx of PMNs, which peaked 6 h post-injection. In a Boyden chamber assay, hrTGF-beta 1 at 1-10 fg/ml elicited a chemotactic response from PMNs greater in magnitude than that evoked by FMLP, establishing that TGF-beta 1 is an effective chemotactic agent for PMNs in vitro as well as in vivo. That PMNs may represent an important source of TGF-beta in inflammatory infiltrates was strongly suggested by a demonstration that stored TGF-beta 1 was secreted during phorbol myristate acetate-stimulated degranulation in vitro. Acid/ethanol extracts of human PMNs assayed by ELISA contained an average of 355 ng of TGF/beta 1 per 10(9) cells potentially available for secretion during degranulation of PMNs. [3H]Thymidine incorporation in vivo and autoradiography of tissue sections revealed that widespread cell proliferation was triggered by TGF-beta 1 injection. Synovial lining cells and cells located deep within the subsynovial connective tissue were identified as sources of at least some of the new cells that contribute to TGF-beta 1-induced hyperplasia. Our results demonstrate that TGF-beta is capable of exerting pathogenic effects on synovial tissue and that PMNs may represent a significant source of the TGF-beta present in synovial effusions.

Expression and secretion of transforming growth factor-beta by bleomycin-stimulated rat alveolar macrophages

1993 ◽  
Vol 264 (1) ◽  
pp. L36-L42 ◽  
Author(s):  
E. M. Denholm ◽  
S. M. Rollins
Keyword(s):  
Growth Factor ◽  
Alveolar Macrophages ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Chemotactic Activity ◽  
Beta Activity ◽  
Dependent Manner ◽  
Tgf Beta ◽  
Growth Factor Beta

Bleomycin-induced fibrosis in rodents has been used extensively as a model of human pulmonary fibrosis. The influx of monocytes observed during the early stages of fibrosis is at least partially regulated by the elaboration of chemotactic factors in the lung. Exposure of alveolar macrophages (AM phi) to bleomycin either in vivo or in vitro stimulated secretion of monocyte chemotactic activity (MCA). This MCA has been previously characterized as being primarily due to fibronectin fragments. The present experiments revealed that bleomycin also induced AM phi to secrete a second chemotactic factor, transforming growth factor-beta (TGF-beta). However, the TGF-beta secreted by macrophages was in latent form, since no TGF-beta activity was detected unless AM phi conditioned medium (CM) was acid-activated. After acidification, chemotactic activity in CM from AM phi stimulated with bleomycin in vitro was increased by 3.6, whereas activity in AM phi CM from fibrotic rats increased by 2 and that of a bleomycin-stimulated AM phi cell line increased by 1.6. This acid-activatable chemotactic activity was inhibited by antibody to TGF-beta. Bleomycin-stimulated AM phi s secreted significantly more TGF-beta than did unstimulated controls. Further, in vitro exposure of AM phi to bleomycin induced TGF-beta mRNA expression in a time- and concentration-dependent manner, with maximal mRNA being detected following a 16-h incubation with 1 microgram/ml bleomycin.

scholarly journals The opposing effects of basic fibroblast growth factor and transforming growth factor beta on the regulation of plasminogen activator activity in capillary endothelial cells.

1987 ◽  
Vol 105 (2) ◽  
pp. 957-963 ◽  
Author(s):  
O Saksela ◽  
D Moscatelli ◽  
D B Rifkin
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Plasminogen Activator ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Fibroblast Growth ◽  
Tgf Beta ◽  
Capillary Endothelial Cells ◽  
Growth Factor Beta

Basic fibroblast growth factor (bFGF), a potent inducer of angiogenesis in vivo, stimulates the production of both urokinase- and tissue-type plasminogen activators (PAs) in cultured bovine capillary endothelial cells. The observed increase in proteolytic activity induced by bFGF was effectively diminished by picogram amounts of transforming growth factor beta (TGF beta), but could not be abolished by increasing the amount of TGF beta. However, the inhibition by TGF beta was greatly enhanced if the cells were pretreated with TGF beta before addition of bFGF. After prolonged incubation of cultures treated simultaneously with bFGF and TGF beta, the inhibitory effect of TGF beta diminished and the stimulatory effect of the added bFGF dominated as assayed by PA levels. TGF beta did not alter the receptor binding of labeled bFGF, nor did a 6-h pretreatment with TGF beta reduce the amount of bFGF bound. The major difference between the effects of bFGF and TGF beta was that while bFGF effectively enhanced PA activity expressed by the cells, TGF beta decreased the amounts of both cell-associated and secreted PA activity by decreasing enzyme production. Both bFGF and TGF beta increased the secretion of the endothelial-type plasminogen activator inhibitor.

THE OPPOSING OF BASIC FIBROBLAST GROWTH FACTOR AND TRANSFORMING GROWTH FACTOR BETA ON THE REGULATION OF PLASMINOGEN ACTIVATOR ACTIVITY IN CAPILLARY ENDOTHELIAL CELLS

1987 ◽  
Author(s):  
O Saksela ◽  
D Moscatelli ◽  
D B Rifkin
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Fibroblast Growth ◽  
Capillary Endothelial Cells ◽  
Growth Factor Beta ◽  
Pai 1

Basic fibroblast growth factor (bFGF), a potent inducer of angio-genesis in vivo, stimulates the production of both the cell-associated and the secreted forms of urokinase-and tissue-type plasminogen activators (PA) in cultured bovine capillary endothelial cells. This stimulation was counteracted by picogram amounts of transforming growth factor beta The stimulatory effect of bFGF was not completely abolished by increasing the amount of TGFb However, the inhibition by TGFb was greatly enhanced if the cells were pretreated for 1-3 hours with TGFb before addition of bFGF, and the inhibition was almost total, if the' preincubationtime with TGFb was 6 hours.Sequential chanqes of serum-containing medium prior to addition ofbFGF also blocked the PA stimulatory effect of bFGF. This inhibitory activity of serum was reduced by incubation of the serum with anti-TGFb-IgG. After pro-longed incubation of cultures treated simultaneously with bFGF' and TGFb, the inhibitory effect of the added bFGF dominated as assayed by PAlevels. TGFbdid not alter the receptor binding of labeled bFGF, nor did a 6 hour pretreatment with TGFb reducethe amount of bound bFGF. The major difference between effects by bFGF and TGFb was thatwhile bFGF effectively enhanced PA-activi-ty expressed by the cells, TGF decreased the amounts of both cell-associated and secreted PA activity by decreasing enzyme production and proenzyme activation. Both bFGF and TGFb increased the secretion of the endothelial type 1 plasminogen activatorinhibitor (PAI 1). The highest concentration of TGFb is found in platelets, and it is known to be released during clot formation. The suppression of PA production by theendothelium by the release of TGFb shouldresult in a decrease in the fibrinolytic activity and promote clot maintenance. In addition, the rapid stimulation of high levels of PAI 1 secretion from the surrounding capillarycells by platelet released TGFb may further suppress fibrinolysis'. The reversabil it.y of theTGFb effect and domination of bFGF stimulation may be important in relation to the subsequentonset of clot lysis or angiogenesis leadino to thrombus reorganization and wound healing.

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