Possible roles for TGF beta 1 in the gastrulating chick embryo

1991 ◽  
Vol 99 (3) ◽  
pp. 617-626 ◽  
Author(s):  
E.J. Sanders ◽  
S. Prasad
Keyword(s):  
Extracellular Matrix ◽  
Chick Embryo ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Phenotype ◽  
Tgf Beta ◽  
Fibronectin Receptor ◽  
Amino Terminal ◽  
Matrix Deposition ◽  
Mesenchymal Transformation

We have examined the immunocytochemical distribution of TGF beta 1 (transforming growth factor beta 1) in the gastrulating chick embryo, and have correlated the results with the ability of this factor to promote in vitro changes in the phenotype of mesoderm and epiblast cells. The findings, together with the demonstration that exogenous TGF beta 1 is also able to modulate extracellular matrix deposition by these cells in culture, are consistent with a role for this factor in the formation and morphogenesis of the early mesoderm. Immunofluorescence analysis, using an antibody to the amino-terminal fragment of TGF beta 1, indicates that this factor is located in, or between, cells of the medial epiblast, Hensen's node and primitive streak. At Hensen's node, cells of the hypoblast were also strongly labelled. Ingressed mesoderm cells, lateral to the streak, show considerably stronger and more diffuse labelling than the overlying epiblast cells. Although the fluorescent labelling appears to be associated with the extracellular matrix surrounding the mesoderm cells, it is not bound to hyaluronic acid, which is the preponderant molecule in the matrix at this time in development. When added exogenously to cultures of mesoderm cells growing with epithelial characteristics on fibronectin, TGF beta 1 effects an epithelial-mesenchymal transformation within 24 h. The reverse transformation is effected in mesoderm cells grown on laminin, while the epiblast cell phenotype is not affected by this treatment regardless of the substratum. TGF beta 1 is also able to down-regulate the deposition of fibronectin by mesoderm cells grown on fibronectin and of epiblast cells grown on laminin, but up-regulate fibronectin deposition by mesoderm on laminin. Similar substratum-dependent changes are seen in laminin deposition, which is down-regulated in mesoderm on laminin and up-regulated in epiblast on laminin. No effect on laminin deposition is seen in either cell type grown on fibronectin. Expression of the fibronectin receptor is also down-regulated by TGF beta 1 in mesoderm cells grown on fibronectin, and this may explain the decreased deposition of fibronectin associated with these cells under these conditions. We suggest that these results are consistent with a reinforcing role for TGF beta 1 in the transformation that results in the emergence of mesoderm cells at gastrulation. This factor may also be involved in the maintenance of the fibroblastic phenotype of the mesoderm cells after their ingression, by effects on the expression of receptors for extracellular matrix and on the deposition of matrix by these cells during their early morphogenesis.

Transforming growth factor beta increases cell surface binding and assembly of exogenous (plasma) fibronectin by normal human fibroblasts

1988 ◽  
Vol 8 (10) ◽  
pp. 4234-4242
Author(s):  
B L Allen-Hoffmann ◽  
C L Crankshaw ◽  
D F Mosher
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Cell Surface ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Human Fibroblasts ◽  
Tgf Beta ◽  
Surface Binding ◽  
Amino Terminal ◽  
Cell Surface Binding

Transforming growth factor beta (TGF-beta) enhances the cell surface binding of 125I-fibronectin by cultured human fibroblasts. The effect of TGF-beta on cell surface binding was maximal after 2 h of exposure to TFG-beta and did not require epidermal growth factor or protein synthesis. The enhancement was dose dependent and was found with the 125I-labeled 70-kilodalton amino-terminal fragment of fibronectin as well as with 125I-fibronectin. Treatment of cultures with TGF-beta for 6 h resulted in a threefold increase in the estimated number of fibronectin binding sites. The increase in number of binding sites was accompanied by an increased accumulation of labeled fibronectin in detergent-insoluble extracellular matrix. The effect of TGF-beta was biphasic; after 6 h of exposure, less labeled fibronectin bound to treated cultures than to control cultures. Exposure of cells to TGF-beta for greater than 6 h caused a two- to threefold increase in the accumulation of cellular fibronectin in culture medium as detected by a quantitative enzyme-linked immunosorbent assay. The second phase of the biphasic effect and the increase in soluble cellular fibronectin were blocked by cycloheximide. Immunofluorescence staining of fibroblast cultures with antifibronectin revealed that TGF-beta caused a striking increase in fibronectin fibrils. The 70-kilodalton amino-terminal fragment of fibronectin, which blocks incorporation of fibronectin into extracellular matrix, blocked anchorage-independent growth of NRK-49F cells in the presence of epidermal growth factor. Our results show that an increase in the binding and rate of assembly of exogenous fibronectin is an early event preceding the increase in expression of extracellular matrix proteins. Such an early increase in cell surface binding of exogenous fibronectin may be a mechanism whereby TGF-beta can modify extracellular matrix characteristics rapidly after tissue injury or during embryonic morphogenesis.

scholarly journals Transforming growth factor beta increases cell surface binding and assembly of exogenous (plasma) fibronectin by normal human fibroblasts.

1988 ◽  
Vol 8 (10) ◽  
pp. 4234-4242 ◽  
Author(s):  
B L Allen-Hoffmann ◽  
C L Crankshaw ◽  
D F Mosher
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Cell Surface ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Human Fibroblasts ◽  
Tgf Beta ◽  
Surface Binding ◽  
Amino Terminal ◽  
Cell Surface Binding

Transforming growth factor beta (TGF-beta) enhances the cell surface binding of 125I-fibronectin by cultured human fibroblasts. The effect of TGF-beta on cell surface binding was maximal after 2 h of exposure to TFG-beta and did not require epidermal growth factor or protein synthesis. The enhancement was dose dependent and was found with the 125I-labeled 70-kilodalton amino-terminal fragment of fibronectin as well as with 125I-fibronectin. Treatment of cultures with TGF-beta for 6 h resulted in a threefold increase in the estimated number of fibronectin binding sites. The increase in number of binding sites was accompanied by an increased accumulation of labeled fibronectin in detergent-insoluble extracellular matrix. The effect of TGF-beta was biphasic; after 6 h of exposure, less labeled fibronectin bound to treated cultures than to control cultures. Exposure of cells to TGF-beta for greater than 6 h caused a two- to threefold increase in the accumulation of cellular fibronectin in culture medium as detected by a quantitative enzyme-linked immunosorbent assay. The second phase of the biphasic effect and the increase in soluble cellular fibronectin were blocked by cycloheximide. Immunofluorescence staining of fibroblast cultures with antifibronectin revealed that TGF-beta caused a striking increase in fibronectin fibrils. The 70-kilodalton amino-terminal fragment of fibronectin, which blocks incorporation of fibronectin into extracellular matrix, blocked anchorage-independent growth of NRK-49F cells in the presence of epidermal growth factor. Our results show that an increase in the binding and rate of assembly of exogenous fibronectin is an early event preceding the increase in expression of extracellular matrix proteins. Such an early increase in cell surface binding of exogenous fibronectin may be a mechanism whereby TGF-beta can modify extracellular matrix characteristics rapidly after tissue injury or during embryonic morphogenesis.

Biochemical characterization of the Drosophila dpp protein, a member of the transforming growth factor beta family of growth factors

1990 ◽  
Vol 10 (6) ◽  
pp. 2669-2677
Author(s):  
G E Panganiban ◽  
K E Rashka ◽  
M D Neitzel ◽  
F M Hoffmann
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Protein ◽  
Stable Complex ◽  
Tgf Beta ◽  
Amino Terminal ◽  
Growth Factor Beta ◽  
Carboxy Terminal

The decapentaplegic (dpp) gene of Drosophila melanogaster is required for pattern formation in the embryo and for viability of the epithelial cells in the imaginal disks. The dpp protein product predicted from the DNA sequence is similar to members of a family of growth factors that includes transforming growth factor beta (TGF-beta). We have produced polyclonal antibodies to a recombinant dpp protein made in bacteria and used a metallothionein promoter to express a dpp cDNA in Drosophila S2 cells. Similar to other proteins in the TGF-beta family, the dpp protein produced by the Drosophila cells was proteolytically cleaved, and both portions of the protein were secreted from the cells. The amino-terminal 47-kilodalton (kDa) peptide was found in the medium and in the proteins adhering to the plastic petri dish. The carboxy-terminal peptide, the region with sequence similarity to the active ligand portion of TGF-beta, was found extracellularly as a 30-kDa homodimer. Most of the 30-kDa homodimer was in the S2 cell protein adsorbed onto the surface of the plastic dish. The dpp protein could be released into solution by increased salt concentration and nonionic detergent. Under these conditions, the amino-terminal and carboxy-terminal portions of dpp were not associated in a stable complex.

The emerging role of transforming growth factor-beta in kidney diseases

1994 ◽  
Vol 266 (6) ◽  
pp. F829-F842 ◽  
Author(s):  
K. Sharma ◽  
F. N. Ziyadeh
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cellular Response ◽  
Transforming Growth Factor ◽  
The Body ◽  
Special Focus ◽  
Tgf Beta ◽  
Growth Factor Beta

Transforming growth factor-beta (TGF-beta) is a prototypical multifunctional cytokine, with growth being only one of its many functions. Its receptors and actions are germane to almost every cell in the body involved in tissue injury and repair, and its effects are best understood in the context of a cellular response to a changing environment. The broad areas in which TGF-beta plays a crucial role include cell proliferation and extracellular matrix production. TGF-beta is a key regulatory molecule in the control of the activity of fibroblasts and has been implicated in several disease states characterized by excessive fibrosis. In the kidney, TGF-beta promotes tubuloepithelial cell hypertrophy and regulates the glomerular production of almost every known molecule of the extracellular matrix, including collagens, fibronectin, tenascin, and proteoglycans, as well as the integrins that are the receptors for these molecules. Furthermore, TGF-beta blocks the destruction of newly synthesized extracellular matrix by upregulating the synthesis of protease inhibitors and downregulating the synthesis of matrix-degrading proteases such as stromelysin and collagenase. As will be discussed, there is a strong body of in vitro and in vivo evidence suggesting that persistent overproduction of TGF-beta 1 in glomeruli after the acute inflammatory stage of glomerulonephritis causes glomerulosclerosis. TGF-beta may also be important in a variety of other chronic renal disorders characterized by hypertrophy and sclerosis, such as diabetic nephropathy. In this review we will attempt to offer a basic understanding of the cellular and molecular biology of TGF-beta and its receptors, with special focus on the role of the TGF-beta system in the kidney during development, growth, and disease.

scholarly journals Control of junB and extracellular matrix protein expression by transforming growth factor-beta 1 is independent of simian virus 40 T antigen-sensitive growth-sensitive growth-inhibitory events.

1991 ◽  
Vol 11 (2) ◽  
pp. 972-978 ◽  
Author(s):  
M Laiho ◽  
L Rönnstrand ◽  
J Heino ◽  
J A Decaprio ◽  
J W Ludlow ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Extracellular Matrix ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Simian Virus 40 ◽  
Plasminogen Activator Inhibitor ◽  
Simian Virus ◽  
T Antigen ◽  
Tgf Beta ◽  
Plasminogen Activator Inhibitor 1

Treatment of Mv1Lu mink lung epithelial cells with transforming growth factor-beta 1 (TGF-beta 1) prevents phosphorylation of the retinoblastoma susceptibility gene product, RB, in late G1 phase of the cell cycle, which is thought to retain RB in a growth-suppressive state. This effect is paralleled by cell cycle arrest in late G1 (M. Laiho, J. A. DeCapric, J. W. Ludlow, D. M. Livingston, and J. Massagué, Cell 62:175-185, 1990). Arrest can be prevented by expression of simian virus 40 T antigen, which binds to underphosphorylated RB, presumably blocking its growth-suppressive activity. The response of cells to TGF-beta 1, however, is complex and includes changes in the levels of expression of genes encoding nuclear transcription factors and extracellular matrix components. To define the relationships among various components of the TGF-beta 1 response, we have investigated the effect of TGF-beta 1 on cells whose growth-inhibitory response to this factor is prevented by T antigen. TGF-beta 1 addition to exponentially growing Mv1Lu cells increased the levels of junB mRNA and of three extracellular matrix proteins: plasminogen activator inhibitor-1, fibronectin, and thrombospondin. Kinetically, the effects on junB and plasminogen activator inhibitor-1 expression occurred faster (half-maximal at 1 to 2 h) than the effects on fibronectin and thrombospondin expression (half-maximal at 6 to 10 h). These effects either preceded or overlapped, respectively, the withdrawal of Mv1Lu cells from the cell cycle. Expression of a transfected T-antigen gene in Mv1Lu cells, however, did not prevent any of these responses to TGF-beta 1. The results indcate that TGF-B1-stimulated expression of junB and extracellular matrix proteins in Mv1Lu cells can occur independently of the T-antigen-sensitive events that lead to growth arrest.

scholarly journals Alterations of the p27KIP1 gene in non-Hodgkin's lymphomas and adult T- cell leukemia/lymphoma

Blood ◽  
1995 ◽  
Vol 86 (5) ◽  
pp. 1924-1930 ◽  
Author(s):  
R Morosetti ◽  
N Kawamata ◽  
AF Gombart ◽  
CW Miller ◽  
Y Hatta ◽  
...  
Keyword(s):  
T Cell ◽  
Southern Blot ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Stop Codon ◽  
Cell Phenotype ◽  
Tgf Beta ◽  
Mutational Status ◽  
P27 Gene ◽  
Hodgkin's Lymphomas

The protein p27KIP1 belongs to a recently identified family of proteins termed cyclin-dependent kinase inhibitors (CDKIs). These proteins play an important role in regulating cell-cycle progression and loss of their function has been implicated in tumorigenesis. Transforming growth factor beta (TGF-beta) may induce cell growth arrest through p27 activation. TGF-beta often loses its ability to arrest growth of transformed cells; this could potentially occur through a defect in p27. To determine the role of p27 in tumorigenesis, we examined its mutational status in 74 non-Hodgkin's lymphomas (NHLs) (52 of B-cell phenotype, 22 of T-cell phenotype), 5 lymphoma cell lines, and 42 adult T-cell leukemias/lymphomas (ATLs) using polymerase chain reaction- single strand conformational polymorphism (PCR-SSCP) and Southern blot analyses. A nonsense mutation (stop codon) that could result in expression of a truncated nonfunctional p27 protein was detected at codon 76 in one case of acute lymphomatous ATL, but not in matched normal tissues. Previously undescribed polymorphisms were also identified at codon 109 in the lymphomas and at codon 55 in the ATLs. Two homozygous deletions of the p27 gene were detected in one case of B- immunoblastic NHL and in one case of acute ATL by Southern blot hybridization. These results indicate that p27 gene alterations are rare events in NHLs and ATLs, but may play an important role in the pathogenesis of some hematologic malignancies.

scholarly journals Biochemical characterization of the Drosophila dpp protein, a member of the transforming growth factor beta family of growth factors.

1990 ◽  
Vol 10 (6) ◽  
pp. 2669-2677 ◽  
Author(s):  
G E Panganiban ◽  
K E Rashka ◽  
M D Neitzel ◽  
F M Hoffmann
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Protein ◽  
Stable Complex ◽  
Tgf Beta ◽  
Amino Terminal ◽  
Growth Factor Beta ◽  
Carboxy Terminal

The decapentaplegic (dpp) gene of Drosophila melanogaster is required for pattern formation in the embryo and for viability of the epithelial cells in the imaginal disks. The dpp protein product predicted from the DNA sequence is similar to members of a family of growth factors that includes transforming growth factor beta (TGF-beta). We have produced polyclonal antibodies to a recombinant dpp protein made in bacteria and used a metallothionein promoter to express a dpp cDNA in Drosophila S2 cells. Similar to other proteins in the TGF-beta family, the dpp protein produced by the Drosophila cells was proteolytically cleaved, and both portions of the protein were secreted from the cells. The amino-terminal 47-kilodalton (kDa) peptide was found in the medium and in the proteins adhering to the plastic petri dish. The carboxy-terminal peptide, the region with sequence similarity to the active ligand portion of TGF-beta, was found extracellularly as a 30-kDa homodimer. Most of the 30-kDa homodimer was in the S2 cell protein adsorbed onto the surface of the plastic dish. The dpp protein could be released into solution by increased salt concentration and nonionic detergent. Under these conditions, the amino-terminal and carboxy-terminal portions of dpp were not associated in a stable complex.

scholarly journals Epithelium-dependent extracellular matrix synthesis in transforming growth factor-beta 1-growth-inhibited mouse mammary gland.

1990 ◽  
Vol 110 (6) ◽  
pp. 2209-2219 ◽  
Author(s):  
G B Silberstein ◽  
P Strickland ◽  
S Coleman ◽  
C W Daniel
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Messenger Rna ◽  
Transforming Growth Factor ◽  
Type I ◽  
Tgf Beta ◽  
Matrix Synthesis ◽  
The Matrix ◽  
Growth Factor Beta

Exogenous transforming growth factor beta (TGF-beta 1) was shown in earlier studies to reversibly inhibit mouse mammary ductal growth. Using small plastic implants to treat regions of developing mammary glands in situ, we now report that TGF-beta 1 growth inhibition is associated with an ectopic accumulation of type I collagen messenger RNA and protein, as well as the glycosaminoglycan, chondroitin sulfate. Both macromolecules are normal components of the ductal extracellular matrix, which, under the influence of exogenous TGF-beta 1, became unusually concentrated immediately adjacent to the epithelial cells at the tip of the ductal growth points, the end buds. Stimulation of extracellular matrix was confined to aggregations of connective tissue cells around affected end buds and was not present around the TGF-beta 1 implants themselves, indicating that the matrix effect was epithelium dependent. Ectopic matrix synthesis was specific for TGF-beta 1 insofar as it was absent at ducts treated with other growth inhibitors, or at ducts undergoing normal involution in response to endogenous regulatory processes. These findings are consistent with the matrix-stimulating properties of TGF-beta 1 reported for other systems, but differ in their strict dependence upon epithelium. A possible role for endogenous TGF-beta 1 in modulating a mammary epithelium-stroma interaction is suggested.

scholarly journals Transforming growth factor-beta 1 regulates axon/Schwann cell interactions.

1995 ◽  
Vol 129 (2) ◽  
pp. 443-458 ◽  
Author(s):  
S Einheber ◽  
M J Hannocks ◽  
C N Metz ◽  
D B Rifkin ◽  
J L Salzer
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Interactions ◽  
Receptor Expression ◽  
Cell Phenotype ◽  
Beta Activity ◽  
Tgf Beta

We have investigated the potential regulatory role of TGF-beta in the interactions of neurons and Schwann cells using an in vitro myelinating system. Purified populations of neurons and Schwann cells, grown alone or in coculture, secrete readily detectable levels of the three mammalian isoforms of TGF-beta; in each case, virtually all of the TGF-beta activity detected is latent. Expression of TGF-beta 1, a major isoform produced by Schwann cells, is specifically and significantly downregulated as a result of axon/Schwann cell interactions. Treatment of Schwann cells or Schwann cell/neuron cocultures with TGF-beta 1, in turn, has dramatic effects on proliferation and differentiation. In the case of purified Schwann cells, treatment with TGF-beta 1 increases their proliferation, and it promotes a pre- or nonmyelinating Schwann cell phenotype characterized by increased NCAM expression, decreased NGF receptor expression, inhibition of the forskolin-mediated induction of the myelin protein P0, and induction of the Schwann cell transcription factor suppressed cAMP-inducible POU protein. Addition of TGF-beta 1 to the cocultures inhibits many of the effects of the axon on Schwann cells, antagonizing the proliferation induced by contact with neurons, and, strikingly, blocking myelination. Ultrastructural analysis of the treated cultures confirmed the complete inhibition of myelination and revealed only rudimentary ensheathment of axons. Associated defects of the Schwann cell basal lamina and reduced expression of laminin were also detected. These effects of TGF-beta 1 on Schwann cell differentiation are likely to be direct effects on the Schwann cells themselves which express high levels of TGF-beta 1 receptors when cocultured with neurons. The regulated expression of TGF-beta 1 and its effects on Schwann cells suggest that it may be an important autocrine and paracrine mediator of neuron/Schwann cell interactions. During development, TGF-beta 1 could serve as an inhibitor of Schwann cell proliferation and myelination, whereas after peripheral nerve injury, it may promote the transition of Schwann cells to a proliferating, nonmyelinating phenotype, and thereby enhance the regenerative response.

scholarly journals Transforming growth factor-beta 1 modulates basic fibroblast growth factor-induced proteolytic and angiogenic properties of endothelial cells in vitro.

1990 ◽  
Vol 111 (2) ◽  
pp. 743-755 ◽  
Author(s):  
M S Pepper ◽  
D Belin ◽  
R Montesano ◽  
L Orci ◽  
J D Vassalli
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Lumen Formation ◽  
Growth Factor Beta ◽  
Pai 1

Tightly controlled proteolytic degradation of the extracellular matrix by invading microvascular endothelial cells is believed to be a necessary component of the angiogenic process. We have previously demonstrated the induction of plasminogen activators (PAs) in bovine microvascular endothelial (BME) cells by three agents that induce angiogenesis in vitro: basic FGF (bFGF), PMA, and sodium orthovanadate. Surprisingly, we find that these agents also induce plasminogen activator inhibitor-1 (PAI-1) activity and mRNA in BME cells. We also find that transforming growth factor-beta 1 (TGF-beta 1), which in vitro modulates a number of endothelial cell functions relevant to angiogenesis, also increases both PAI-1 and urokinase-type PA (u-PA) mRNA. Thus, production of both proteases and protease inhibitors is increased by angiogenic agents and TGF-beta 1. However, the kinetics and amplitude of PAI-1 and u-PA mRNA induction by these agents are strikingly different. We have used the ratio of u-PA:PAI-1 mRNA levels as an indicator of proteolytic balance. This ratio is tilted towards enhanced proteolysis in response to bFGF, towards antiproteolysis in response to TGF-beta 1, and is similar to that in untreated cultures when the two agents are added simultaneously. Using an in vitro angiogenesis assay in three-dimensional fibrin gels, we find that TGF-beta 1 inhibits the bFGF-induced formation of tube-like structures, resulting in the formation of solid endothelial cell cords within the superficial parts of the gel. These results suggest that a net positive proteolytic balance is required for capillary lumen formation. A novel perspective is provided on the relationship between extracellular matrix invasion, lumen formation, and net proteolytic balance, thereby reflecting the interplay between angiogenesis-modulating cytokines such as bFGF and TGF-beta 1.

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