scholarly journals Enhanced production and extracellular deposition of the endothelial-type plasminogen activator inhibitor in cultured human lung fibroblasts by transforming growth factor-beta.

1986 ◽  
Vol 103 (6) ◽  
pp. 2403-2410 ◽  
Author(s):  
M Laiho ◽  
O Saksela ◽  
P A Andreasen ◽  
J Keski-Oja
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Transforming Growth Factor Beta ◽  
Culture Medium ◽  
Transforming Growth Factor ◽  
Lung Fibroblasts ◽  
Tissue Type ◽  
Metabolic Labeling ◽  
Tgf Beta ◽  
Growth Factor Beta

Cultured human embryonic lung fibroblasts were used as a model to study the effects of transforming growth factor-beta (TGF beta) on the plasminogen activator (PA) activity released by nontumorigenic cells into the culture medium. The cells were exposed to TGF beta under serum-free conditions, and the changes in PA activity and protein metabolism were analyzed by caseinolysis-in-agar assays, zymography, and polypeptide analysis. Treatment of the cells with TGF beta caused a significant decrease in the PA activity of the culture medium as analyzed by the caseinolysis-in-agar assays. The quantitatively most prominent effect of TGF beta on confluent cultures of cells was the induction of an Mr 47,000 protein, as detected by metabolic labeling. The Mr 47,000 protein was a PA inhibitor as judged by reverse zymography. It was antigenically related to a PA inhibitor secreted by HT-1080 tumor cells as demonstrated with monoclonal antibodies. The induced Mr 47,000 inhibitor was deposited into the growth substratum of the cells, as detected by metabolic labeling, immunoblotting analysis, and reverse zymography assays of extracellular matrix preparations. TGF beta also decreased the amounts of urokinase-type and tissue-type PAs accumulated in the conditioned medium, as detected by zymography. Epidermal growth factor antagonized the inhibitory effects of TGF beta by enhancing the amounts of the PAs. These results indicate that growth factors modulate the proteolytic balance of cultured cells by altering the amounts of PAs and their inhibitors.

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.

Cytokine signaling in lung: transforming growth factor-beta secretion by lung fibroblasts

1991 ◽  
Vol 260 (2) ◽  
pp. L123-L128 ◽  
Author(s):  
J. Kelley ◽  
J. P. Fabisiak ◽  
K. Hawes ◽  
M. Absher
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Phenotypic Expression ◽  
Soft Agar ◽  
Lung Fibroblast ◽  
Lung Fibroblasts ◽  
Tgf Beta ◽  
Anchorage Independent Growth ◽  
Growth Factor Beta

Control of growth and phenotypic expression of interstitial fibroblasts is a critical determinant of lung architecture and physiology during processes of growth and remodeling. We examined the ability of lung fibroblasts to produce transforming growth factor-beta (TGF-beta), a cytokine that is known to modulate proliferation and phenotypic expression of mesenchymal cells. Cultures of fibroblasts isolated from rat lungs spontaneously secrete TGF-beta as measured in the standard bioassay of anchorage-independent growth of normal rat kidney (NRK) cells in soft agar. Rat lung fibroblasts secrete TGF-beta in an inactive precursor form. Fibroblasts cultured from adult and fetal rat lungs produced comparable amounts of TGF-beta. The ability of lung fibroblast supernatant fluids to induce colony formation in soft agar could be completely neutralized by preincubation of samples with anti-TGF-beta immunoglobulin (Ig). Anti-platelet-derived growth factor IgG had no effect on anchorage-independent growth of NRK cells driven by rat fibroblast culture supernatant samples. These results indicate that TGF-beta does not require the presence of and interaction with secondary cytokines for its activity. In contrast to the results obtained with rat cells, neither human fetal nor adult lung fibroblasts secreted detectable amount of active TGF-beta or its inactive precursor. This was not due to the presence of TGF-beta inhibitors in fibroblast culture media, because the addition of purified porcine TGF-beta to conditioned medium from human lung fibroblast cultures yielded the expected increase in NRK cell growth in soft agar. These results point to differing cytokine control patterns in the lungs of the two species.

scholarly journals Lipoprotein (a) inhibits the generation of transforming growth factor beta: an endogenous inhibitor of smooth muscle cell migration.

1991 ◽  
Vol 113 (6) ◽  
pp. 1439-1445 ◽  
Author(s):  
S Kojima ◽  
P C Harpel ◽  
D B Rifkin
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Cell Migration ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Culture Medium ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Smooth Muscle Cell Migration ◽  
Growth Factor Beta

Conditioned medium (CM) derived from co-cultures of bovine aortic endothelial cells (BAECs) and bovine smooth muscle cells (BSMCs) contains transforming growth factor-beta (TGF-beta) formed via a plasmin-dependent activation of latent TGF-beta (LTGF beta), which occurs in heterotypic but not in homotypic cultures (Sato, Y., and D. B. Rifkin. 1989. J. Cell Biol. 107: 1199-1205). The TGF-beta formed is able to block the migration of BSMCs or BAECs. We have found that the simultaneous addition to heterotypic culture medium of plasminogen and the atherogenic lipoprotein, lipoprotein (a) (Lp(a)), which contains plasminogen-like kringles, inhibits the activation of LTGF-beta in a dose-dependent manner. The inclusion of LDL in the culture medium did not show such an effect. Control experiments indicated that Lp(a) does not interfere with the basal level of cell migration, the activity of exogenous added TGF-beta, the release of LTGF-beta from cells, the activation of LTGF-beta either by plasmin or by transient acidification, or the activity of plasminogen activator. The addition of Lp(a) to the culture medium decreased the amount of plasmin found in BAECs/BSMCs cultures. Similar results were obtained using CM derived from cocultures of human umbilical vein endothelial cells and human foreskin fibroblasts. These results suggest that Lp(a) can inhibit the activation of LTGF-beta by competing with the binding of plasminogen to cell or matrix surfaces. Therefore, high plasma levels of Lp(a) might enhance smooth muscle cell migration by decreasing the levels of the migration inhibitor TGF-beta thus contributing to generation of the atheromatous lesions.

scholarly journals Mechanism of differential inhibition of factor-dependent cell proliferation by transforming growth factor-beta 1: selective uncoupling of FMS from MYC

Blood ◽  
1993 ◽  
Vol 81 (10) ◽  
pp. 2539-2546
Author(s):  
AR Chen ◽  
LR Rohrschneider
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Growth Regulation ◽  
Transforming Growth Factor ◽  
Metabolic Labeling ◽  
Tgf Beta ◽  
Western Blots ◽  
Gm Csf ◽  
Growth Factor Beta

Transforming growth factor-beta 1 (TGF-beta 1) selectively modulates hematopoietic cell proliferation. The proliferation of FDC-P1 clone MAC- 11, a factor-dependent murine myeloid progenitor cell line, was inhibited differentially by TGF-beta 1: strongly in macrophage colony- stimulating factor (M-CSF), mildly in interleukin-3, and not at all in granulocyte-macrophage-CSF (GM-CSF). Flow cytometry and Western blots showed an unexpected increase in expression of FMS, the receptor for M- CSF, in response to TGF-beta 1. Metabolic labeling with 35S-methionine showed that synthesis of FMS protein accelerated in response to TGF- beta 1, whereas its degradation was unaffected. Northern analyses showed a rapid increase in c-fms RNA after the addition of TGF-beta 1. TGF-beta 1 did not affect kinase activity, cellular phosphotyrosine response, or internalization of FMS. However, TGF-beta 1 inhibited the induction by M-CSF of c-myc RNA analyzed on Northern blots and protein detected by radioimmuno-precipitation. TGF-beta 1 did not affect induction of c-myc expression by GM-CSF or induction of c-fos or c-jun by M-CSF. Therefore, FMS and the GM-CSF receptor induce c-myc via signal transduction pathways that differ in that only the former is inhibited by TGF-beta 1. This inhibition may account for the selective growth regulation by TGF-beta 1.

Transforming growth factor-beta selectively inhibits branching morphogenesis but not tubulogenesis

1997 ◽  
Vol 272 (1) ◽  
pp. F139-F146 ◽  
Author(s):  
H. Sakurai ◽  
S. K. Nigam
Keyword(s):  
Growth Factor ◽  
Conditioned Medium ◽  
Plasminogen Activator ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Mdck Cells ◽  
Branching Morphogenesis ◽  
Tgf Beta ◽  
3T3 Cells ◽  
Growth Factor Beta

When cultured in type I collagen gels, two kidney-derived cell lines, Madin-Darby canine kidney (MDCK) cells and murine inner medullary collecting duct (mIMCD3) cells, from branching tubular structures in the presence of Swiss 3T3 conditioned medium, in which hepatocyte growth factor (HGF) is the major branching tubule inducing factor. However, upon incubation with transforming growth factor-beta (TGF-beta) in the presence of 3T3 conditioned medium, MDCK tubulogenesis and branching was markedly inhibited. In contrast, mIMCD3 cells, which are much less susceptible to growth and tubulogenesis inhibition by TGF-beta, formed long straight tubulelike structures in presence of TGF-beta, suggesting a dissociation between tubulogenesis and branching morphogenesis. Interestingly, those long tubules that did branch often superficially resembled the early branching ureteric bud in embryonic kidneys. Quantitation of branching events revealed a selective branch-inhibiting effect of TGF-beta on mIMCD3 cells at concentrations between 0.02 and 2 ng/ml. There was no qualitative or quantitative difference among TGF-beta 1, -beta 2, and -beta 3 on inhibition of branching events, suggesting existence of potentially redundant mechanisms for modulating branching morphogenesis. Concentrations of TGF-beta that resulted in long nonbranching tubules also altered the profile of extracellular matrix-degrading proteases and their inhibitors expressed by developing tubules. Ratios of urokinase type plasminogen activator (u-PA) to plasminogen activator inhibitor (PAI-l) and matrix metalloprotease (MMP)-1 to tissue inhibitor of metalloprotease (TIMP)-1 were both markedly decreased. In addition, apart from a direct effect on epithelial cell branching morphogenesis, TGF-beta downregulated the expression of HGF mRNA in Swiss 3T3 cells. Thus TGF-beta exerts at least three distinct effects relevant to tubulogenesis and branching morphogenesis inhibition of branching morphogenesis alone (mIMCD3 cells), inhibition of both tubulogenesis and branching morphogenesis (MDCK cells), and inhibition of the expression of growth factor which induce tubulogenesis and branching morphogenesis (3T3 cells). In the context of epithelial tissue development, which requires tightly regulated branching tubulogenesis of epithelial cells, the data suggest a model where branching patterns are regulated by a precise temporal and spatial balance between branching morphogens such as HGF and inhibitory morphogens such as members of the TGF-beta superfamily [e.g., TGF-beta isoforms, certain bone morphogenetic proteins].

scholarly journals Mechanism of differential inhibition of factor-dependent cell proliferation by transforming growth factor-beta 1: selective uncoupling of FMS from MYC

Blood ◽  
1993 ◽  
Vol 81 (10) ◽  
pp. 2539-2546 ◽  
Author(s):  
AR Chen ◽  
LR Rohrschneider
Keyword(s):  
Cell Proliferation ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Growth Regulation ◽  
Transforming Growth Factor ◽  
Metabolic Labeling ◽  
Tgf Beta ◽  
Western Blots ◽  
Gm Csf ◽  
Growth Factor Beta

Abstract Transforming growth factor-beta 1 (TGF-beta 1) selectively modulates hematopoietic cell proliferation. The proliferation of FDC-P1 clone MAC- 11, a factor-dependent murine myeloid progenitor cell line, was inhibited differentially by TGF-beta 1: strongly in macrophage colony- stimulating factor (M-CSF), mildly in interleukin-3, and not at all in granulocyte-macrophage-CSF (GM-CSF). Flow cytometry and Western blots showed an unexpected increase in expression of FMS, the receptor for M- CSF, in response to TGF-beta 1. Metabolic labeling with 35S-methionine showed that synthesis of FMS protein accelerated in response to TGF- beta 1, whereas its degradation was unaffected. Northern analyses showed a rapid increase in c-fms RNA after the addition of TGF-beta 1. TGF-beta 1 did not affect kinase activity, cellular phosphotyrosine response, or internalization of FMS. However, TGF-beta 1 inhibited the induction by M-CSF of c-myc RNA analyzed on Northern blots and protein detected by radioimmuno-precipitation. TGF-beta 1 did not affect induction of c-myc expression by GM-CSF or induction of c-fos or c-jun by M-CSF. Therefore, FMS and the GM-CSF receptor induce c-myc via signal transduction pathways that differ in that only the former is inhibited by TGF-beta 1. This inhibition may account for the selective growth regulation by TGF-beta 1.

scholarly journals Altered metabolic and adhesive properties and increased tumorigenesis associated with increased expression of transforming growth factor beta 1.

1992 ◽  
Vol 118 (3) ◽  
pp. 715-726 ◽  
Author(s):  
B A Arrick ◽  
A R Lopez ◽  
F Elfman ◽  
R Ebner ◽  
C H Damsky ◽  
...  
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Tumor Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tumor Formation ◽  
Expression Vectors ◽  
Tgf Beta ◽  
Growth Factor Beta

Transforming growth factor-beta (TGF-beta) is a potent mediator of cell proliferation and extracellular matrix formation, depending on the cell type and the physiological conditions. TGF-beta is usually secreted in a "latent" complex that needs activation before it can exert its effects. Several observations correlate increased expression of TGF-beta 1 with tumorigenesis. To evaluate the physiological relevance of increased TGF-beta 1 synthesis in tumor cells we established cell clones overexpressing TGF-beta 1 and observed the resulting physiological changes in TGF-beta overproducing cells in vitro and in vivo. As a model system we used the human E1A-transformed 293 tumor cells, which are insensitive to the direct growth modulatory effects of TGF-beta. The selection of this cell line allows an assessment of physiological alterations independent of TGF-beta induced proliferative changes. The use of two TGF-beta 1 expression vectors containing either the natural or a modified TGF-beta 1 precursor cDNA permitted the establishment of separate 293 cell lines overexpressing latent or active TGF-beta. Comparison of the resulting changes in glycolytic rate, adhesiveness and integrin and plasminogen activator expression established that, in vitro, both types of clones behaved similarly, indicating that expression of latent TGF-beta induces autocrine changes in the tumor cells and thus suggesting that some level of cell-associated activation occurs. TGF-beta overexpression resulted in an increased metabolic rate due to enhanced glycolysis, a property long associated with tumor cells. This increased glycolysis was not associated with altered proliferation. Cells overexpressing TGF-beta also displayed enhanced fibronectin mRNA and plasminogen activator synthesis and increased adhesiveness in vitro. They showed enhanced survival when plated sparsely on plastic in the absence of serum, and attached more readily to laminin. In addition, synthesis of several beta 1 integrins, in particular the alpha 1/beta 1, alpha 2/beta 1, and alpha 3/beta 1, all of which recognize laminin, were enhanced. Finally, cells overexpressing active TGF-beta, but not latent TGF-beta, also showed increased tumorigenicity in nude mice. Thus, an increase in endogenous TGF-beta synthesis confers several proliferation-independent phenotypic changes which may be of significance for the survival of the tumor cell inoculum or its subsequent growth, and for tumor formation and development. In the case of cells expressing active TGF-beta, the release of active TGF-beta into the vicinity of the tumor cells may also result in a more hospitable environment for tumor growth.

scholarly journals Characterization of the activation of latent TGF-beta by co-cultures of endothelial cells and pericytes or smooth muscle cells: a self-regulating system.

1990 ◽  
Vol 111 (2) ◽  
pp. 757-763 ◽  
Author(s):  
Y Sato ◽  
R Tsuboi ◽  
R Lyons ◽  
H Moses ◽  
D B Rifkin
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Transforming Growth Factor Beta ◽  
Neutralizing Antibodies ◽  
Culture Medium ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Growth Factor Beta ◽  
Pai 1

The conversion of latent transforming growth factor beta (LTGF-beta) to the active species, transforming growth factor beta (TGF-beta), has been characterized in heterotypic cultures of bovine aortic endothelial (BAE) cells and bovine smooth muscle cells (SMCs). The formation of TGF-beta in co-cultures of BAE cells and SMCs was documented by a specific radioreceptor competition assay, while medium from homotypic cultures of BAE cells or SMCs contained no active TGF-beta as determined by this assay. The concentration of TGF-beta in the conditioned medium of heterotypic co-cultures was estimated to be 400-1,200 pg/ml using the inhibition of BAE cell migration as an assay. Northern blotting of poly A+ RNA extracted from both homotypic and heterotypic cultures of BAE cells and SMCs revealed that BAE cells produced both TGF-beta 1 and TGF-beta 2, while SMCs produced primarily TGF-beta 1. No change in the expression of these two forms of TGF-beta was apparent after 24 h in heterotypic cultures. Time course studies on the appearance of TGF-beta indicated that most of the active TGF-beta was generated within the first 12 h after the establishment of co-cultures. The generation of TGF-beta in co-cultures stimulated the production of the protease inhibitor plasminogen activator inhibitor-1 (PAI-1). The inclusion of neutralizing antibodies to TGF-beta in the co-culture medium blocked the observed increase in PAI-1 levels. The increased expression of PAI-1 subsequent to TGF-beta formation blocked the activation of the protease required for conversion of LTGF-beta to TGF-beta as the inclusion of neutralizing antibodies to PAI-1 in the co-culture medium resulted in prolonged production of TGF-beta. This effect was lost upon removal of the PAI-1 antibodies. Thus, the activation of LTGF-beta appears to be a self-regulating system.

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