scholarly journals Differences in the binding of transforming growth factor β1 to the acute-phase reactant and constitutively synthesized α-macroglobulins of rat

1995 ◽  
Vol 312 (2) ◽  
pp. 579-586 ◽  
Author(s):  
D J Webb ◽  
K P Crookston ◽  
N L Figler ◽  
J Lamarre ◽  
S L Gonias
Keyword(s):  
Growth Factor ◽  
Conformational Change ◽  
Acute Phase ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Dissociation Constants ◽  
Physiological Role ◽  
Acute Phase Reactant ◽  
Tgf Beta ◽  
Phase Reactant

Human alpha 2-macroglobulin (alpha 2M) is a proteinase inhibitor and carrier of certain growth factors, including transforming growth factor beta 1 (TGF-beta 1). The constitutively synthesized homologue of human alpha 2M in the adult rat is alpha 1M. Rat alpha 2M is an acute-phase reactant, expressed at high levels in experimental trauma, pregnancy and in certain pathological conditions. The physiological role of rat alpha 2M is not known. In this investigation, we demonstrated that rat alpha 1M and rat alpha 2M bind TGF-beta 1. The equilibrium dissociation constants (KD) for the binding of TGF-beta 1 to the native forms of alpha 1M and alpha 2M were 257 and 109 nM respectively. alpha 1M underwent conformational change when it reacted with methylamine. The resulting product bound TGF-beta 1 with higher affinity (32 nM). Methylamine-treated rat alpha 2M did not undergo conformational change and did not bind TGF-beta 1 with increased affinity. Previous studies suggest that the native conformation may be the principal form responsible for the cytokine-carrier activity of alpha 2M in plasma and serum-supplemented cell culture medium. To confirm that native rat alpha 2M is a more efficient TGF-beta 1 carrier than native alpha 1M, fetal bovine heart endothelial cell (FBHE) proliferation assays were performed. TGF-beta 1 (5 pM) inhibited FBHE proliferation, and native alpha 2M (0.3 microM) counteracted this activity whereas alpha 1M (0.3 microM) had almost no effect. Rat alpha 2M underwent conformational change when it reacted with plasmin incorporating 1.1 mol of plasmin/mol. alpha 2M-plasmin bound TGF-beta 1; the KD (61 nM) was lower (P < 0.01) than that determined for the native alpha 2M-TGF-beta 1 interaction. These studies demonstrate that both rat alpha-macroglobulins are carriers of TGF-beta 1. The native form of rat alpha 2M probably has a predominant role, compared with native alpha 1M, as a TGF-beta 1 carrier in the plasma during the acute-phase response.

scholarly journals Identification of a novel transforming growth factor-beta (TGF-beta 5) mRNA in Xenopus laevis.

1990 ◽  
Vol 265 (2) ◽  
pp. 1089-1093 ◽  
Author(s):  
P Kondaiah ◽  
M J Sands ◽  
J M Smith ◽  
A Fields ◽  
A B Roberts ◽  
...  
Keyword(s):  
Growth Factor ◽  
Xenopus Laevis ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Growth Factor Beta

scholarly journals Transforming growth factor-beta modulates the high-affinity receptors for epidermal growth factor and transforming growth factor-alpha.

1985 ◽  
Vol 100 (5) ◽  
pp. 1508-1514 ◽  
Author(s):  
J Massagué
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Affinity Labeling ◽  
Tgf Beta ◽  
Semisolid Medium ◽  
High Affinity ◽  
Receptor Structure ◽  
Epidermal Growth

The epidermal growth factor (EGF) receptor mediates the induction of a transformed phenotype in normal rat kidney (NRK) cells by transforming growth factors (TGFs). The ability of EGF and its analogue TGF-alpha to induce the transformed phenotype in NRK cells is greatly potentiated by TGF-beta, a polypeptide that does not interact directly with binding sites for EGF or TGF-alpha. Our evidence indicates that TGF-beta purified from retrovirally transformed rat embryo cells and human platelets induces a rapid (t 1/2 = 0.3 h) decrease in the binding of EGF and TGF-alpha to high-affinity cell surface receptors in NRK cells. No change due to TGF-beta was observed in the binding of EGF or TGF-alpha to lower affinity sites also present in NRK cells. The effect of TGF-beta on EGF/TGF-alpha receptors was observed at concentrations (0.5-20 pM) similar to those at which TGF-beta is active in promoting proliferation of NRK cells in monolayer culture and semisolid medium. Affinity labeling of NRK cells and membranes by cross-linking with receptor-bound 125I-TGF-alpha and 125I-EGF indicated that both factors interact with a common 170-kD receptor structure. Treatment of cells with TGF-beta decreased the intensity of affinity-labeling of this receptor structure. These data suggest that the 170 kD high-affinity receptors for EGF and TGF-alpha in NRK cells are a target for rapid modulation by TGF-beta.

scholarly journals Recombinant type 1 transforming growth factor beta precursor produced in Chinese hamster ovary cells is glycosylated and phosphorylated.

1988 ◽  
Vol 8 (5) ◽  
pp. 2229-2232 ◽  
Author(s):  
A M Brunner ◽  
L E Gentry ◽  
J A Cooper ◽  
A F Purchio
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Chinese Hamster Ovary ◽  
Transforming Growth Factor ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Tgf Beta ◽  
Ovary Cells ◽  
Growth Factor Beta

Analyses of cDNA clones coding for simian type 1 transforming growth factor beta (TGF-beta 1) suggest that there are three potential sites for N-linked glycosylation located in the amino terminus of the precursor region. Analysis of [3H]glucosamine-labeled serum-free supernatants from a line of Chinese hamster ovary cells which secrete high levels of recombinant TGF-beta 1 indicate that the TGF-beta 1 precursor, but not the mature form, is glycosylated. Digestion with neuraminidase resulted in a shift in migration of the two TGF-beta 1 precursor bands, which suggests that they contain sialic acid residues. Endoglycosidase H had no noticeable effect. Treatment with N-glycanase produced two faster-migrating sharp bands, the largest of which had a molecular weight of 39 kilodaltons. TGF-beta 1-specific transcripts produced by SP6 polymerase programmed the synthesis of a 42-kilodalton polypeptide which, we suggest, is the unmodified protein backbone of the precursor. Labeling with 32Pi showed that the TGF-beta 1 precursor was phosphorylated in the amino portion of the molecule.

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.

Cloning of a growth arrest-specific and transforming growth factor beta-regulated gene, TI 1, from an epithelial cell line

1991 ◽  
Vol 11 (10) ◽  
pp. 5338-5345
Author(s):  
B Kallin ◽  
R de Martin ◽  
T Etzold ◽  
V Sorrentino ◽  
L Philipson
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Type I ◽  
Tgf Beta ◽  
Protein Synthesis Inhibitors ◽  
Plasminogen Activator Inhibitor 1 ◽  
Growth Factor Beta

By cDNA cloning and differential screening, five genes that are regulated by transforming growth factor beta (TGF beta) in mink lung epithelial cells were identified. A novel membrane protein gene, TI 1, was identified which was downregulated by TGF beta and serum in quiescent cells. In actively growing cells, the TI 1 gene is rapidly and transiently induced by TGF beta, and it is overexpressed in the presence of protein synthesis inhibitors. It appears to be related to a family of transmembrane glycoproteins that are expressed on lymphocytes and tumor cells. The four other genes were all induced by TGF beta and correspond to the genes of collagen alpha type I, fibronectin, plasminogen activator inhibitor 1, and the monocyte chemotactic cell-activating factor (JE gene) previously shown to be TGF beta regulated.

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.

Sign in / Sign up

Export Citation Format

Share Document