scholarly journals Transforming growth factor-beta activity is potentiated by heparin via dissociation of the transforming growth factor-beta/alpha 2-macroglobulin inactive complex.

1989 ◽  
Vol 109 (1) ◽  
pp. 441-448 ◽  
Author(s):  
T A McCaffrey ◽  
D J Falcone ◽  
C F Brayton ◽  
L A Agarwal ◽  
F G Welt ◽  
...  
Keyword(s):  
Biological Activity ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Antiproliferative Effect ◽  
Tgf Beta ◽  
Binding Studies ◽  
Growth Inhibitory ◽  
Growth Factor Beta

The control of smooth muscle cell (SMC) proliferation is determined by the combined actions of mitogens, such as platelet-derived growth factor, and the opposing action of growth inhibitory agents, such as heparin and transforming growth factor-beta (TGF-beta). The present studies identify an interaction between heparin and TGF-beta in which heparin potentiates the biological action of TGF-beta. Using a neutralizing antibody to TGF-beta, we observed that the short term antiproliferative effect of heparin depended upon the presence of biologically active TGF-beta. This effect was observed in rat and bovine aortic SMC and in CCL64 cells, but not in human saphenous vein SMC. Binding studies demonstrated that the addition of heparin (100 micrograms/ml) to medium containing 10% plasma-derived serum resulted in a 45% increase in the specific binding of 125I-TGF-beta to cells. Likewise, heparin induced a twofold increase in the growth inhibitory action of TGF-beta at concentrations of TGF-beta near its apparent dissociation constant. Using 125I-labeled TGF-beta, we demonstrated that TGF-beta complexes with the plasma component alpha 2-macroglobulin, but not with fibronectin. Heparin increases the electrophoretic mobility of TGF-beta apparently by freeing TGF-beta from its complex with alpha 2-macroglobulin. Dextran sulfate, another highly charged antiproliferative molecule, but not chondroitin sulfate or dermatan sulfate, similarly modified TGF-beta's mobility. Relatively high, antiproliferative concentrations of heparin (1-100 micrograms/ml) were required to dissociate the TGF-beta/alpha 2-macroglobulin complex. Thus, it appears that the antiproliferative effect of heparin may be partially attributed to its ability to potentiate the biological activity of TGF-beta by dissociating it from alpha 2-macroglobulin, which normally renders it inactive. We suggest that heparin-like agents may be important regulators of TGF-beta's biological activity.

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.

scholarly journals Retinoic acid induces transforming growth factor-beta 2 in cultured keratinocytes and mouse epidermis.

1989 ◽  
Vol 1 (1) ◽  
pp. 87-97 ◽  
Author(s):  
A B Glick ◽  
K C Flanders ◽  
D Danielpour ◽  
S H Yuspa ◽  
M B Sporn
Keyword(s):  
Retinoic Acid ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Tgf Beta ◽  
Mouse Epidermis ◽  
Cultured Keratinocytes ◽  
Growth Factor Beta ◽  
Beta 2

We have studied the functional interaction between retinoic acid and transforming growth factor-beta (TGF-beta), using the mouse epidermis as a model system. Treatment with retinoic acid increases expression of TGF-beta 2 in cultured keratinocytes in vitro, as well as in the epidermis in vivo. This TGF-beta 2 is secreted in a biologically active form that can bind to surface receptors, in contrast to most other conditions in which TGF-beta is secreted in a latent form. Specific antibodies to TGF-beta 2 partially reverse the ability of retinoic acid to inhibit DNA synthesis in cultured keratinocytes. The regulation of TGF-beta 2 expression by retinoic acid may have important physiological and pharmacological roles in the maintenance of epidermal homeostasis.

scholarly journals Quercetin inhibits the growth of leukemic progenitors and induces the expression of transforming growth factor-beta 1 in these cells

Blood ◽  
1995 ◽  
Vol 85 (12) ◽  
pp. 3654-3661 ◽  
Author(s):  
LM Larocca ◽  
L Teofili ◽  
S Sica ◽  
M Piantelli ◽  
N Maggiano ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Inhibitory Activity ◽  
Transforming Growth Factor ◽  
Dependent Manner ◽  
Tgf Beta ◽  
Acute Leukemias ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
Growth Factor Beta

We previously showed that quercetin (3,3′,4′,5,7 pentahydroxyflavone) inhibits in a dose-dependent manner the growth of acute leukemias and is able to enhance the antiproliferative activity of cytosine arabinoside. We show here that quercetin inhibits the clonogenic activity of 20 of 22 acute leukemias (AL; 4 M1-AML, 3 M2-AML, 2 M3-AML, 3 M4-AML, 3 M5-AML, and 7 ALL). In the present report, we show that the induction of transforming growth factor-beta 1 (TGF-beta 1) in leukemic blasts is one of the growth-inhibitory mechanisms of quercetin in these cells. This observation was supported by the following data. (1) Quercetin-sensitive leukemic blasts, when treated with quercetin, secrete large amounts of TGF-beta 1 in the medium and show positivity for TGF-beta 1-immunoreactive material in the cytoplasm. (2) At a concentration of 8 mumol/L, antisense TGF-beta 1 oligonucleotides prevent the growth-inhibitory action of quercetin. (3) Anti-TGF-beta 1 neutralizing monoclonal antibodies can prevent almost completely the growth-inhibitory activity of quercetin. The analysis of quercetin-resistant cases confirmed as well the central role of TGF-beta 1 in the growth-inhibitory activity of quercetin. In conclusion, quercetin can act as a cytostatic agent for leukemic cells by modulating the production of TGF-beta 1.

scholarly journals Molecular events in the processing of recombinant type 1 pre-pro-transforming growth factor beta to the mature polypeptide.

1988 ◽  
Vol 8 (10) ◽  
pp. 4162-4168 ◽  
Author(s):  
L E Gentry ◽  
M N Lioubin ◽  
A F Purchio ◽  
H Marquardt
Keyword(s):  
Biological Activity ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cho Cells ◽  
Transforming Growth Factor ◽  
Proteolytic Processing ◽  
Tgf Beta ◽  
Recombinant Type ◽  
Growth Factor Beta

Recently, the simian type 1 transforming growth factor beta (TGF-beta 1) cDNA was expressed at high levels in Chinese hamster ovary (CHO) cells by dihydrofolate reductase-induced gene amplification (L.E. Gentry, N.R. Webb, G.J. Lim, A.M. Brunner, J.E. Ranchalis, D.R. Twardzik, M.N. Lioubin, H. Marquardt, and A.F. Purchio, Mol. Cell. Biol. 7:3418-3427, 1987). We have now purified and characterized the recombinant proteins released by these cells. Analyses of the precursor proteins by amino acid sequencing identified potentially important proteolytic processing sites. Signal peptide cleavage occurs at the Gly-29-Leu-30 peptide bond of pre-pro-TGF-beta 1, yielding pro-TGF-beta 1 (30 to 390). In addition, proteolytic processing of the precursor to yield mature TGF-beta 1 occurs at the dibasic cleavage site immediately preceding Ala-279, indicating that CHO cells possess the appropriate processing enzyme. Greater than 95% of the biological activity detected in the conditioned medium of the CHO transfectant was due to mature, properly processed growth factor. Highly purified recombinant TGF-beta 1 had the same specific biological activity as natural TGF-beta 1. The concentration of TGF-beta 1 required for half-maximal inhibition of Mv1Lu mink lung epithelial cell growth was approximately 1 to 2 pM. Purified precursor inhibited mink lung cell proliferation at 50 to 60 pM concentrations. The purified precursor preparation was shown to consist of pro-TGF-beta 1 (30 to 390), the pro region of the precursor (30 to 278), and mature TGF-beta 1 (279 to 390) interlinked by at least one disulfide bond with the pro portion of the precursor. These recombinant forms of TGF-beta1 should prove useful for further structural and functional studies.

Glucocorticoid regulation of transforming growth factor beta 1 activity and binding in osteoblast-enriched cultures from fetal rat bone

1991 ◽  
Vol 11 (9) ◽  
pp. 4490-4496
Author(s):  
M Centrella ◽  
T L McCarthy ◽  
E Canalis
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Type I ◽  
Tgf Beta ◽  
Binding Studies ◽  
Fetal Rat ◽  
Growth Factor Beta ◽  
Enriched Cultures ◽  
Rat Bone

Transforming growth factor beta (TGF-beta) enhances replication and bone matrix protein synthesis and associates with distinct binding sites in osteoblast-enriched cultures from fetal rat bone. In the organism high levels of or sustained exposure to glucocorticoids alters bone cell activity and decreases bone mass, effects that may be mediated in part by changes in local TGF-beta actions in skeletal tissue. Preexposure of osteoblast-enriched cultures to 100 nM cortisol reduced the stimulatory effects of TGF-beta 1 on DNA and collagen synthesis by 40 to 50%. Binding studies showed that cortisol moderately enhanced total TGF-beta 1 binding, but chemical cross-linking and polyacrylamide gel electrophoretic analysis revealed an increase only within Mr 250,000 (type III) TGF-beta-binding complexes, which are thought to represent extracellular TGF-beta storage sites. In contrast, a decrease in TGF-beta 1 binding was detected in Mr 65,000 (type I) and 85,000 (type II) complexes, which have been implicated as signal-transducing TGF-beta receptors. Our present studies therefore indicate that glucocorticoids can decrease the anabolic effects of TGF-beta 1 in bone, and these may occur in part by a redistribution of its binding toward extracellular matrix storage sites. Alterations of this sort could contribute to bone loss associated with glucocorticoid excess.

Molecular events in the processing of recombinant type 1 pre-pro-transforming growth factor beta to the mature polypeptide

1988 ◽  
Vol 8 (10) ◽  
pp. 4162-4168
Author(s):  
L E Gentry ◽  
M N Lioubin ◽  
A F Purchio ◽  
H Marquardt
Keyword(s):  
Biological Activity ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cho Cells ◽  
Transforming Growth Factor ◽  
Proteolytic Processing ◽  
Tgf Beta ◽  
Recombinant Type ◽  
Growth Factor Beta

Recently, the simian type 1 transforming growth factor beta (TGF-beta 1) cDNA was expressed at high levels in Chinese hamster ovary (CHO) cells by dihydrofolate reductase-induced gene amplification (L.E. Gentry, N.R. Webb, G.J. Lim, A.M. Brunner, J.E. Ranchalis, D.R. Twardzik, M.N. Lioubin, H. Marquardt, and A.F. Purchio, Mol. Cell. Biol. 7:3418-3427, 1987). We have now purified and characterized the recombinant proteins released by these cells. Analyses of the precursor proteins by amino acid sequencing identified potentially important proteolytic processing sites. Signal peptide cleavage occurs at the Gly-29-Leu-30 peptide bond of pre-pro-TGF-beta 1, yielding pro-TGF-beta 1 (30 to 390). In addition, proteolytic processing of the precursor to yield mature TGF-beta 1 occurs at the dibasic cleavage site immediately preceding Ala-279, indicating that CHO cells possess the appropriate processing enzyme. Greater than 95% of the biological activity detected in the conditioned medium of the CHO transfectant was due to mature, properly processed growth factor. Highly purified recombinant TGF-beta 1 had the same specific biological activity as natural TGF-beta 1. The concentration of TGF-beta 1 required for half-maximal inhibition of Mv1Lu mink lung epithelial cell growth was approximately 1 to 2 pM. Purified precursor inhibited mink lung cell proliferation at 50 to 60 pM concentrations. The purified precursor preparation was shown to consist of pro-TGF-beta 1 (30 to 390), the pro region of the precursor (30 to 278), and mature TGF-beta 1 (279 to 390) interlinked by at least one disulfide bond with the pro portion of the precursor. These recombinant forms of TGF-beta1 should prove useful for further structural and functional studies.

scholarly journals Transforming growth factor-beta complexes with thrombospondin.

1992 ◽  
Vol 3 (2) ◽  
pp. 181-188 ◽  
Author(s):  
J E Murphy-Ullrich ◽  
S Schultz-Cherry ◽  
M Höök
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Neutralizing Antibody ◽  
Gel Permeation Chromatography ◽  
Soft Agar ◽  
Biologically Active ◽  
Dependent Manner ◽  
Tgf Beta ◽  
Growth Factor Beta

Thrombospondin (TSP) was demonstrated to inhibit the growth of bovine aortic endothelial cells, an activity that was not neutralized by antibodies to TSP or by other agents that block TSP-cell interactions but that partially was reversed by a neutralizing antibody to transforming growth factor-beta (TGF-beta). Similar to TGF-beta, TSP supported the growth of NRK-49F colonies in soft agar in a dose-dependent manner, which required epidermal growth factor and was neutralized by anti-TGF-beta antibody. Chromatography of a TSP preparation did not separate the TGF-beta-like NRK colony-forming activity from high molecular weight protein. However, when chromatography was performed at pH 11, this activity was dissociated from TSP. These results suggest that at least some growth modulating activities of TSP are due to TGF-beta associated with TSP by strong non-covalent forces. Most of the active TGF-beta released from platelets after degranulation was associated with TSP, as demonstrated by anti-TSP immunoaffinity and gel permeation chromatography. 125I-TGF-beta binds to purified TSP in an interaction that is specific in the sense that bound TGF-beta could be displaced by TGF-depleted TSP but not significantly by native TSP, heparin, decorin, alpha 2-macroglobulin, fibronectin, or albumin. Hence, TGF-beta can bind to TSP, and the complex forms under physiological conditions. Furthermore, TSP-associated TGF-beta is biologically active, and the binding of TGF-beta to TSP may protect TGF-beta from extracellular inactivators.

scholarly journals A glycosylation-deficient endothelial cell mutant with modified responses to transforming growth factor-beta and other growth inhibitory cytokines: evidence for multiple growth inhibitory signal transduction pathways.

1993 ◽  
Vol 4 (2) ◽  
pp. 135-144 ◽  
Author(s):  
V Fafeur ◽  
B O'Hara ◽  
P Böhlen
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tnf Alpha ◽  
Type I ◽  
Tgf Beta ◽  
Ifn Gamma ◽  
Beta Receptor ◽  
Growth Inhibitory ◽  
Growth Factor Beta

An endothelial cell line (M40) resistant to growth inhibition by transforming growth factor-beta type 1 (TGF beta 1) was isolated by chemical mutagenesis and growth in the presence of TGF beta 1. Like normal endothelial cells, this mutant is characterized by high expression of type II TGF beta receptor and low expression of type I TGF beta receptor. However, the mutant cells display a type II TGF beta receptor of reduced molecular weight as a result of a general defect in N-glycosylation of proteins. The alteration does not impair TGF beta 1 binding to cell surface receptors or the ability of TGF beta 1 to induce fibronectin or plasminogen activator inhibitor-type I production. M40 cells were also resistant to growth inhibition by tumor necrosis factor alpha (TNF alpha) and interleukin-1 alpha (IL-1 alpha) but were inhibited by interferon-gamma (IFN gamma) and heparin. These results imply that TGF beta 1, TNF alpha, and IL-1 alpha act through signal transducing pathways that are separate from pathways for IFN gamma and heparin. Basic fibroblast growth factor was still mitogenic for M40, further suggesting that TGF beta 1, TNF alpha, and IL-1 alpha act by direct inhibition of cell growth rather than by interfering with growth stimulatory pathways.

scholarly journals Glucocorticoid regulation of transforming growth factor beta 1 activity and binding in osteoblast-enriched cultures from fetal rat bone.

1991 ◽  
Vol 11 (9) ◽  
pp. 4490-4496 ◽  
Author(s):  
M Centrella ◽  
T L McCarthy ◽  
E Canalis
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Type I ◽  
Tgf Beta ◽  
Binding Studies ◽  
Fetal Rat ◽  
Growth Factor Beta ◽  
Enriched Cultures ◽  
Rat Bone

Transforming growth factor beta (TGF-beta) enhances replication and bone matrix protein synthesis and associates with distinct binding sites in osteoblast-enriched cultures from fetal rat bone. In the organism high levels of or sustained exposure to glucocorticoids alters bone cell activity and decreases bone mass, effects that may be mediated in part by changes in local TGF-beta actions in skeletal tissue. Preexposure of osteoblast-enriched cultures to 100 nM cortisol reduced the stimulatory effects of TGF-beta 1 on DNA and collagen synthesis by 40 to 50%. Binding studies showed that cortisol moderately enhanced total TGF-beta 1 binding, but chemical cross-linking and polyacrylamide gel electrophoretic analysis revealed an increase only within Mr 250,000 (type III) TGF-beta-binding complexes, which are thought to represent extracellular TGF-beta storage sites. In contrast, a decrease in TGF-beta 1 binding was detected in Mr 65,000 (type I) and 85,000 (type II) complexes, which have been implicated as signal-transducing TGF-beta receptors. Our present studies therefore indicate that glucocorticoids can decrease the anabolic effects of TGF-beta 1 in bone, and these may occur in part by a redistribution of its binding toward extracellular matrix storage sites. Alterations of this sort could contribute to bone loss associated with glucocorticoid excess.

scholarly journals Evidence for an age-related dysfunction in the antiproliferative response to transforming growth factor-beta in vascular smooth muscle cells.

1993 ◽  
Vol 4 (3) ◽  
pp. 315-322 ◽  
Author(s):  
T A McCaffrey ◽  
D J Falcone
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Muscle Cells ◽  
Type I ◽  
Tgf Beta ◽  
Binding Studies ◽  
Growth Factor Beta

Previous studies have indicated that aged animals show an increased intimal hyperplasia after arterial injury. The present studies examined the hypothesis that the increased serum-free proliferation of aged smooth muscle cells (SMC), in vitro, was due to a loss of an antiproliferative signal, such as transforming growth factor-beta 1 (TGF-beta 1). Northern blot analysis of the mRNA derived from old (> 19 mo) or young (3-4 mo) rat aortic SMC indicated that both groups had an equivalent level of the 2.5 kB TGF-beta 1 message. Metabolic labeling with 35S-methionine and immunoprecipitation for TGF-beta 1 confirmed the de novo synthesis of TGF-beta 1 in rat SMC. Old and young SMC supernatants showed equal levels of active or latent (acid-activated) TGF-beta activity. Despite the similarities in the production of TGF-beta 1, old SMC were refractory to inhibition by TGF-beta 1, whereas young SMC were markedly inhibited (80%) by low levels of TGF-beta 1 (IC50 < 5 pg/ml). Binding studies at 4 degrees C indicated that old SMC exhibited reduced binding capacity for 125I-TGF-beta 1. Cross-linking studies confirmed that old SMC showed reduced binding of 125I-TGF-beta 1 to membrane sites corresponding to the high molecular weight type III receptor, as well as the 85-kDa type II and 65-kDa type I receptor. However, at 37 degrees C, old SMC degraded 125I-TGF-beta 1 more rapidly than young SMC. Combined, this data suggests that SMC derived from older animals are capable of normal production of TGF-beta 1 but fail to respond to the autocrine growth inhibitory effects of this agent, thereby leading to enhanced proliferation.

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