scholarly journals Non-uniform influence of transforming growth factor-β on the biosynthesis of different forms of small chondroitin sulphate/dermatan sulphate proteoglycan

1990 ◽  
Vol 269 (2) ◽  
pp. 551-554 ◽  
Author(s):  
B Breuer ◽  
G Schmidt ◽  
H Kresse
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Core Protein ◽  
Chondroitin Sulphate ◽  
Transforming Growth Factor Β ◽  
Cell Types ◽  
Osteosarcoma Cell ◽  
Tgf Beta ◽  
Small Proteoglycan

The influence of transforming growth factor-beta (TGF-beta) on the expression of different forms of small proteoglycans was investigated in human skin fibroblasts and in a human osteosarcoma cell line. TGF-beta was not found to act as a general stimulator of small proteoglycan biosynthesis. In both cell types, an increased expression of the core protein of proteoglycan I was found. However, there was a profound decrease in the expression of a 106 kDa core protein, and either no alteration or a small decrease in the biosynthesis of the collagen-binding small proteoglycan II core protein. These results show that the production of individual members of the small proteoglycan family is differentially regulated.

scholarly journals Distribution and modulation of the cellular receptor for transforming growth factor-beta.

1987 ◽  
Vol 105 (2) ◽  
pp. 965-975 ◽  
Author(s):  
L M Wakefield ◽  
D M Smith ◽  
T Masui ◽  
C C Harris ◽  
M B Sporn
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Types ◽  
Tgf Beta ◽  
Cell Type ◽  
Down Regulation ◽  
Growth Factor Beta ◽  
Different Cell Types

Scatchard analyses of the binding of transforming growth factor-beta (TGF-beta) to a wide variety of different cell types in culture revealed the universal presence of high affinity (Kd = 1-60 pM) receptors for TGF-beta on every cell type assayed, indicating a wide potential target range for TGF-beta action. There was a strong (r = +0.85) inverse relationship between the receptor affinity and the number of receptors expressed per cell, such that at low TGF-beta concentrations, essentially all cells bound a similar number of TGF-beta molecules per cell. The binding of TGF-beta to various cell types was not altered by many agents that affect the cellular response to TGF-beta, suggesting that modulation of TGF-beta binding to its receptor may not be a primary control mechanism in TGF-beta action. Similarly, in vitro transformation resulted in only relatively small changes in the cellular binding of TGF-beta, and for those cell types that exhibited ligand-induced down-regulation of the receptor, down-regulation was not extensive. Thus the strong conservation of binding observed between cell types is also seen within a given cell type under a variety of conditions, and receptor expression appears to be essentially constitutive. Finally, the biologically inactive form of TGF-beta, which constitutes greater than 98% of autocrine TGF-beta secreted by all of the twelve different cell types assayed, was shown to be unable to bind to the receptor without prior activation in vitro. It is proposed that this may prevent premature interaction of autocrine ligand and receptor in the Golgi apparatus.

scholarly journals Phosphorylation of the human-transforming-growth-factor-β-binding protein endoglin

1994 ◽  
Vol 301 (3) ◽  
pp. 765-768 ◽  
Author(s):  
P Lastres ◽  
J Martín-Perez ◽  
C Langa ◽  
C Bernabéu
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Mouse Fibroblast ◽  
Tgf Beta ◽  
Kinase C ◽  
Protein Kinase C Inhibitor ◽  
A Minor ◽  
Minor Extent

Endoglin is an homodimeric membrane antigen with capacity to bind transforming growth factor-beta (TGF-beta). Phosphorylation of human endoglin was demonstrated in endothelial cells as well as in mouse fibroblast transfectants expressing two isoforms, L-endoglin or S-endoglin, with distinct cytoplasmic domains. The extent of L-endoglin phosphorylation was found to be 8-fold higher than that of S-endoglin, and phosphopeptide analyses revealed at least three different phosphorylation sites for L-endoglin, whereas S-endoglin produces only one phosphopeptide. The immunoprecipitated L-endoglin was found to be phosphorylated mainly on serine, and, to a minor extent, on threonine, residues. Treatment of the cells with TGF-beta 1 or the protein kinase C inhibitor H-7 resulted in a reduction of the levels of endoglin phosphorylation.

scholarly journals Cell type-specific control of human neuronectin secretion by polypeptide mediators and phorbol ester.

1989 ◽  
Vol 37 (12) ◽  
pp. 1777-1786 ◽  
Author(s):  
W J Rettig ◽  
P Garin-Chesa
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Malignant Tumors ◽  
Tissue Injury ◽  
Mesenchymal Cell ◽  
Cell Types ◽  
Skin Lesions ◽  
Psoriatic Skin ◽  
Tgf Beta

Neuronectin (NEC1) is a human extracellular matrix (ECM) protein expressed with a unique rostrocaudal pattern in white matter of the normal adult central nervous system. In addition, NEC1 is expressed in normal fetal and adult smooth muscle, along certain epithelial-mesenchymal junctions, and transiently in developing fetal cartilage. Region-specific induction of NEC1 is found in dermal wounds and in the reactive stroma of actinic keratoses, psoriatic skin lesions, and a range of malignant tumors. One explanation for these diverse tissue patterns is that cells capable of producing NEC1 are widely distributed in neural and mesenchymal tissues, but they become NEC1 producers only when induced by region-specific differentiation signals. In this study, we used cultured human cells to show that several regulatory polypeptides, including fibroblast growth factors, tumor necrosis factor, platelet-derived growth factor, nerve growth factor, and transforming growth factor-beta (TGF-beta), as well as 12-O-tetradecanoyl phorbol-13-acetate (TPA), modulate NEC1 secretion, with distinct patterns of inducing and inhibitory activities in different neural and mesenchymal cell types. TPA and TGF-beta act both as inducers and inhibitors of NEC1 secretion, depending on the target cell. These effects are specific for NEC1 and are not seen for several other secreted and membrane proteins studied. We suggest that NEC1 expression comes under different modes of extrinsic control in different cell lineages and in response to tissue injury and neoplasia.

scholarly journals Regulation of transformation-sensitive secreted phosphoprotein (SPPI/osteopontin) expression by transforming growth factor-β. Comparisons with expression of SPARC (secreted acidic cysteine-rich protein)

1991 ◽  
Vol 273 (3) ◽  
pp. 523-531 ◽  
Author(s):  
J L Wrana ◽  
T Kubota ◽  
Q Zhang ◽  
C M Overall ◽  
J E Aubin ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Bone Repair ◽  
Transforming Growth Factor ◽  
Bone Cells ◽  
Mrna Level ◽  
Parietal Bone ◽  
Osteoblastic Cells ◽  
Osteosarcoma Cell ◽  
Tgf Beta

Secreted phosphoprotein I (SPPI; osteopontin), a highly phosphorylated form of which has been associated with cell transformation, is one of the major phosphorylated proteins in bone. Populations of rat bone cells derived from fetal calvariae, neonatal parietal bone and a rat osteosarcoma cell line (ROS 17/2.8) produce several forms of the protein, the major forms having apparent molecular masses of 55 and 44 kDa by SDS/PAGE on 15% (w/v) cross-linked gels and of 60 and 56 kDa on 10% gels. Northern blot analysis of SPPI mRNA using total cellular RNA revealed a single 1.5 kb mRNA species, indicating that the nascent protein chains of these phosphoproteins are identical. On treatment of the cells with transforming growth factor-beta (TGF-beta; 1 ng/ml), the levels of SPPI mRNA and the synthesis of the 55 kDa phosphoprotein, but not of the 44 kDa phosphoprotein, were increased by 1.8-4.5-fold in the normal osteoblastic cells, the stimulation first being evident at 3 h and reaching a maximum at 12 h. In the transformed ROS 17/2.8 cells, TGF-beta did not alter significantly the SPPI mRNA level or the synthesis of either the 55 kDa or the 44 kDa SPPI over the 24 h period studied. By comparison, neither the steady-state levels of SPARC (secreted protein, acidic, rich in cysteine) mRNA nor the synthesis of SPARC protein were affected significantly by the addition of TGF-beta to any of the osteoblastic bone cells. The half-lives for SPPI and SPARC mRNAs in the osteoblastic calvarial cells were calculated to be 18 h and greater than 50 h respectively, in both the presence and the absence of TGF-beta. Since the stability of the mRNA was unchanged by TGF-beta and the increased expression of SPPI mRNA could be blocked by cycloheximide, TGF-beta appears to increase transcription of the SppI gene indirectly by stimulating the synthesis of a protein that promotes transcription. These results demonstrate that several forms of SPPI are synthesized constitutively by bone cells, and that there are clear differences in the regulation of SppI gene expression by TGF-beta in normal bone cells compared with the tumorigenic ROS 17/2.8 cells. The differential responses of normal osteoblastic cells to TGF-beta in the expression of SPPI and the selective stimulation of specific forms of the SPPI protein may be important in bone repair and remodelling.

scholarly journals Degradation of decorin by matrix metalloproteinases: identification of the cleavage sites, kinetic analyses and transforming growth factor-β1 release

1997 ◽  
Vol 322 (3) ◽  
pp. 809-814 ◽  
Author(s):  
Kazushi IMAI ◽  
Ari HIRAMATSU ◽  
Daikichi FUKUSHIMA ◽  
Michael D. PIERSCHBACHER ◽  
Yasunori OKADA
Keyword(s):  
Growth Factor ◽  
Matrix Metalloproteinases ◽  
Transforming Growth Factor ◽  
Core Protein ◽  
Chondroitin Sulphate ◽  
Transforming Growth Factor Β ◽  
Transforming Growth Factor Β1 ◽  
Extracellular Milieu ◽  
Tissue Reactions ◽  
Tgf Β1

Decorin (DCN) is a ubiquitous proteoglycan comprised of a core protein attached to a single dermatan/chondroitin sulphate glycosaminoglycan chain. It may play a role in regulation of collagen fibrillogenesis and function as a reservoir of transforming growth factor β(TGF-β) in the extracellular milieu. We have examined the susceptibility of DCN to five different matrix metalloproteinases (MMPs): MMP-1 (tissue collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin 1), MMP-7 (matrilysin) and MMP-9 (gelatinase B). MMP-2 and MMP-3 digest DCN into seven major fragments in a similar pattern. The N-terminal sequence of the two fragments generated by MMP-2 and MMP-3 is Leu211-Lys-Gly-Leu-Asn, but that of the others is Asp1-Glu-Ala-Ser-Gly. MMP-7 cleaves DCN into three major fragments which have the N-termini Asp1-Glu-Ala-Ser-Gly, Glu2-Ala-Ser-Gly-Ile and Leu244-His-Leu-Asp-Asn. Activities of MMP-1 and MMP-9 against DCN are negligible. The values of Km for the MMPs capable of degrading DCN are very similar (10–12 μM), but the kcat/Km value for MMP-7 (30.5 μM-1·h-1) is 4.5-fold higher than those for MMP-2 and MMP-3. Incubation of a DCN–TGF-β1 complex with MMP-2, -3 or -7 results in release of TGF-β1 from the complex. These data indicate proteolytic degradation of DCN by MMP-2, MMP-3 and MMP-7, and suggest the possibility that, under pathophysiological conditions, the digestion by the MMPs may induce tissue reactions mediated by TGF-β1 released from DCN in the connective tissues.

scholarly journals Inhibition of Nb2 T-lymphoma cell growth by transforming growth factor-β

1988 ◽  
Vol 253 (1) ◽  
pp. 295-298 ◽  
Author(s):  
E J Rayhel ◽  
D A Prentice ◽  
P S Tabor ◽  
W H Flurkey ◽  
R W Geib ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Transforming Growth Factor Β ◽  
Tgf Beta ◽  
Inhibitory Effects ◽  
Nb2 Cells ◽  
Growth Factor Beta ◽  
T Lymphoma

Transforming growth factor-beta (TGF-beta) inhibits proliferation of Nb2 cells, a rat T lymphoma, in response to lactogens and interleukin-2. Prostaglandins may play an important role in the pathway through which TGF-beta exerts its inhibitory actions, because prostaglandin E2 also inhibits proliferation of Nb2 cells, and indomethacin, an inhibitor of prostaglandin synthesis, reverses the inhibitory effects of TGF-beta on Nb2 cell proliferation.

scholarly journals Membrane-anchored and soluble forms of betaglycan, a polymorphic proteoglycan that binds transforming growth factor-beta.

1989 ◽  
Vol 109 (6) ◽  
pp. 3137-3145 ◽  
Author(s):  
J L Andres ◽  
K Stanley ◽  
S Cheifetz ◽  
J Massagué
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Core Protein ◽  
Culture Media ◽  
Cell Types ◽  
Type I ◽  
Tgf Beta ◽  
Beta Receptor ◽  
Core Proteins ◽  
Membrane Bound

Transforming growth factors beta 1 and beta 2 bind with high affinity to the core protein of a 250-350-kD cell surface proteoglycan. This proteoglycan (formerly referred to as the type III TGF-beta receptor) coexists in many cells with the receptor implicated in TGF-beta signal transduction (type I TGF-beta receptor), but its function is not known. We report here that soluble TGF-beta-binding proteoglycans are released by several cell types into the culture media, and can be found in serum and extracellular matrices. As has been shown for the membrane-bound form, the soluble proteoglycans have a heterogeneous core protein of 100-120 kD that carries chondroitin sulfate and/or heparan sulfate glycosaminoglycan chains and a small amount of N-linked carbohydrate. The membrane-bound form of this proteoglycan is hydrophobic and associates with liposomes, whereas the soluble forms lack a membrane anchor and do not associate with liposomes. Differences in the electrophoretic migration of the soluble and membrane forms of this proteoglycan suggest additional structural differences in their core proteins and glycosaminoglycan chains. These soluble and membrane-bound proteoglycans, for which we propose the name "betaglycans," might play distinct roles in pericellular retention, delivery, or clearance of activated TGF-beta.

scholarly journals Transforming-growth-factor-β activation elements in the distal promoter regions of the rat α1 type I collagen gene

1991 ◽  
Vol 280 (1) ◽  
pp. 157-162 ◽  
Author(s):  
J D Ritzenthaler ◽  
R H Goldstein ◽  
A Fine ◽  
A Lichtler ◽  
D W Rowe ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transcriptional Activation ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Collagen Type I ◽  
Type I ◽  
Tgf Beta ◽  
Mobility Shift

We have located a cis-acting element (alpha 1-TAE) within the promoter sequences of the rat collagen alpha 1(I) gene (COL1A1) 1600 bases upstream of the transcription start site which mediates transcriptional activation by transforming growth factor beta (TGF-beta). The functional significance of this region was established by (1) deletion analysis of the alpha 1(I) promoter cloned upstream of the bacterial chloramphenicol acetyltransferase (CAT) gene and (2) by co-transfection of promoter constructs with double-stranded oligonucleotides. DNA-mobility-shift assays with radiolabelled alpha 1-TAE demonstrated increased nuclear binding activity after TGF-beta stimulation. Oligonucleotides encoding the alpha 1-TAE, additional upstream regions within the alpha 1(I) promoter, as well as consensus nuclear-factor-1 (NF-1) sequences, competed with the alpha 1-TAE sequence. The two collagen type I genes are stimulated by TGF-beta through different regions of their promoters.

scholarly journals Altered structure of the hybrid cell surface proteoglycan of mammary epithelial cells in response to transforming growth factor-beta.

1988 ◽  
Vol 107 (5) ◽  
pp. 1959-1967 ◽  
Author(s):  
S Rasmussen ◽  
A Rapraeger
Keyword(s):  
Growth Factor ◽  
Cell Surface ◽  
Heparan Sulfate ◽  
Chondroitin Sulfate ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Core Protein ◽  
Mammary Epithelial ◽  
Tgf Beta ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta) is a polypeptide growth factor that affects the accumulation of extracellular matrix by many cell types. We have examined the ability of mouse mammary epithelial (NMuMG) cells to respond to TGF-beta and assessed the effect of the growth factor on the expression of their cell surface heparan sulfate/chondroitin sulfate hybrid proteoglycan. NMuMG cells respond maximally to 3 ng/ml TGF-beta and the response is consistent with occupancy of the type III receptor. However, cells that are polarized, as shown by sequestration of the cell surface PG at their basolateral surfaces, must have the growth factor supplied to that site for maximal response. Immunological quantification of proteoglycan core protein on treated cells suggests that the cells have an unchanging number of this proteoglycan at their cell surface. Nonetheless, metabolic labeling with radiosulfate shows a approximately 2.5-fold increase in 35SO4-glycosaminoglycans in this proteoglycan fraction, defined either by its lipophilic, antigenic, or cell surface properties. Kinetic studies indicate that the enhanced radiolabeling is due to augmented synthesis, rather than slower degradation. Analysis of the glycosaminoglycan composition of the proteoglycan shows an increased amount of chondroitin sulfate, suggesting that the increased labeling per cell may be attributed to an augmented synthesis of chondroitin sulfate glycosaminoglycan on the core protein that also bears heparan sulfate, thus altering the proportions of these two glycosaminoglycans on this hybrid proteoglycan. We conclude that TGF-beta may affect NMuMG cell behavior by altering the structure and thus the activity of this proteoglycan.

scholarly journals Collagen synthesis by human fibroblasts. Regulation by transforming growth factor-β in the presence of other inflammatory mediators

1989 ◽  
Vol 260 (2) ◽  
pp. 463-469 ◽  
Author(s):  
A S Narayanan ◽  
R C Page ◽  
J Swanson
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Collagen Synthesis ◽  
Transforming Growth Factor ◽  
Human Fibroblasts ◽  
Transforming Growth Factor Β ◽  
Tgf Beta ◽  
Collagen Production ◽  
Collagen Mrna ◽  
In Cells

We have examined the combined effects of transforming growth factor-beta (TGF-beta), serum and gamma-interferon (gamma-IFN) on collagen synthesis by fibroblasts and compared the response of fibroblast subpopulations to TGF-beta. Human diploid fibroblasts were treated with TGF-beta alone and with serum of gamma-IFN. Cells were labelled with radioactive amino acids, and collagen production was measured as collagenase-digestible radioactivity. Collagen mRNA was determined by a solution-hybridization assay using procollagen-alpha 1[I] cDNA clone HF 677. The results showed that either serum or TGF-beta increased incorporation, collagen production and mRNA by fibroblasts approx. 2-fold; however, collagen synthesis relative to total protein synthesis and collagen mRNA relative to total polyadenylated [poly(A)+] RNA were not affected. Only serum activated cell growth. Collagen production increased approx. 4-fold in cells exposed to both TGF-beta and serum, and this increase was equal to that expected for an additive effect by both components. Treatment with gamma-IFN decreased collagen production and collagen mRNA to 44 and 40% respectively, whereas total incorporation and poly(A)+ RNA were affected only marginally. Cells exposed simultaneously to both gamma-IFN and TGF-beta produced less collagen and contained less mRNA than did those treated with TGF-beta alone. The gamma-IFN decreased collagen synthesis in control and TGF-beta-treated cultures to a similar extent, and TGF-beta increased collagen synthesis 2-fold in cells pre-treated with gamma-IFN. Fibroblast strains obtained in medium containing plasma-derived serum synthesized approximately half as much collagen as did cells derived from the same explant in the presence of fresh human serum, and TGF-beta stimulated collagen production and mRNA in both cell strains. We conclude that TGF-beta, serum and gamma-IFN regulate collagen synthesis by independent mechanisms, and that the combined action of these components plays a significant role in regulating collagen synthesis during wound healing and tissue repair.

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