scholarly journals Carrageenans inhibit growth-factor binding

1993 ◽  
Vol 289 (2) ◽  
pp. 331-334 ◽  
Author(s):  
R Hoffman
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Platelet Derived Growth Factor ◽  
Transforming Growth Factor Alpha ◽  
Fibroblast Growth ◽  
Tgf Beta ◽  
Factor Alpha ◽  
Growth Factor Beta ◽  
Kappa Carrageenan

Carrageenans, a family of polysulphated carbohydrates, inhibited binding of basic fibroblast growth factor (bFGF), transforming growth factor beta 1 (TGF beta 1) and platelet-derived growth factor (PDGF). iota-Carrageenan was the most potent bFGF antagonist (IC50 = 0.4 +/- 0.1 microgram/ml), kappa-carrageenan was the most potent PDGF antagonist (IC50 = 1.7 +/- 1.3 micrograms/ml) and lambda-carrageenan was the most potent TGF beta 1 antagonist (IC50 = 19 +/- 2 micrograms/ml). None of the carrageenans, at concentrations up to 200 micrograms/ml, inhibited binding of insulin-like growth factor 1 or transforming growth factor alpha. Carrageenans are selective growth-factor antagonists and have potential for the treatment of disorders associated with the over-production of certain growth factors.

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.

Induction of chondrogenesis: requirement for synergistic interaction of basic fibroblast growth factor and transforming growth factor-beta

Development ◽  
1994 ◽  
Vol 120 (2) ◽  
pp. 415-424 ◽  
Author(s):  
D.A. Frenz ◽  
W. Liu ◽  
J.D. Williams ◽  
V. Hatcher ◽  
V. Galinovic-Schwartz ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Otic Capsule ◽  
Fibroblast Growth ◽  
Tgf Beta ◽  
Growth Factor Beta

Interactions between the epithelial anlage of the developing mouse inner ear and its associated periotic mesenchyme control the differentiation of the cartilaginous otic capsule. Transforming growth factor-beta 1 (TGF-beta 1) is a naturally occurring signal peptide that is present in these tissues at times of active differentiation and morphogenesis. Previous studies have shown that TGF-beta 1 alone is not a sufficient stimulus to initiate chondrogenesis in cultured periotic mesenchyme. In this study, we provide evidence that basic fibroblast growth factor (bFGF) can elicit a specific but limited chondrogenic response in cultured periotic mesenchymal cells. We also demonstrate that simultaneous addition of bFGF and TGF-beta 1 to cultured periotic mesenchyme results in a full chondrogenic response comparable to that which occurs when periotic mesenchyme is grown in the presence of its natural inductor tissue (i.e. otic epithelium). Utilizing antibodies directed against bFGF, we show localization of endogenous bFGF in the otic epithelium in vivo and in mixed epithelial-mesenchymal cultures. Additionally, we demonstrate the presence of FGF-like activity in medium conditioned by otic epithelium. Blocking of epithelial elicited chondrogenesis by a combination of both alpha bFGF and alpha TGF-beta 1 antibodies provides further evidence of the necessity for these growth factors in the chondrogenic differentiation of periotic mesenchyme in vitro. Our results suggest a role for both bFGF and TGF-beta 1 in the regulation of chondrogenesis during otic capsule formation in situ.

Regulation of fibroblast-mediated collagen gel contraction by platelet-derived growth factor, interleukin-1 alpha and transforming growth factor-beta 1

1992 ◽  
Vol 102 (2) ◽  
pp. 315-322 ◽  
Author(s):  
A. Tingstrom ◽  
C.H. Heldin ◽  
K. Rubin
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 1 ◽  
Collagen Gel ◽  
Platelet Derived Growth Factor ◽  
Tgf Beta ◽  
Collagen Gels ◽  
Collagen Gel Contraction ◽  
Growth Factor Beta

We have examined the effects of three macrophage-derived cytokines, platelet-derived growth factor (PDGF), transforming growth factor-beta 1 (TGF-beta 1) and interleukin-1 alpha (IL-1 alpha) on the contraction of collagen type I gels populated by human foreskin fibroblasts. Contraction was quantified as loss in gel weight. Both PDGF-AA and PDGF-BB were found to induce a rapid collagen-gel contraction. TGF-beta 1 also stimulated gel contraction but with a delayed onset and at a slower rate than the PDGF-stimulated contraction. Rabbit polyclonal IgGs recognizing PDGF-AA and PDGF-BB, respectively, specifically inhibited the effects of the corresponding PDGF isoforms. However, the stimulatory effect of TGF-beta 1 was not affected by any of the anti-PDGF antibodies. The ability of PDGF to stimulate contraction became less pronounced in collagen gel cultures grown in the absence of growth factors over periods of several days. Under the same conditions, the stimulatory effect of TGF-beta 1 was not reduced. The reduced response to PDGF may be due to reduced tension on fibroblasts growing in collagen gels, since fibroblasts on free-floating gels showed a marked reduction in PDGF-BB-induced PDGF beta-receptor aggregates when compared to fibroblasts on attached collagen gels. IL-1 alpha inhibited initial collagen gel contraction, and at later stages induced a visible degradation of the collagen gels, presumably due to the generation of collagenase activity. The combination of IL-1 alpha and PDGF-BB stimulated initial collagen gel contraction, although less effectively than PDGF-BB alone.(ABSTRACT TRUNCATED AT 250 WORDS)

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