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Schmees C, Villaseñor R, Zheng W, Ma H, Zerial M, Heldin CH, Hellberg C. Macropinocytosis of the PDGF β-receptor promotes fibroblast transformation by H-RasG12V. Mol Biol Cell 2012; 23:2571-82. [PMID: 22573884 PMCID: PMC3386220 DOI: 10.1091/mbc.e11-04-0317] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Fibroblast transformation by H-RasG12V induces internalization of PDGFRβ by macropinocytosis, enhancing its signaling activity and increasing anchorage-independent proliferation. It is proposed that H-Ras transformation promotes tumor progression by enhancing growth factor receptor signaling through increased receptor macropinocytosis. Receptor tyrosine kinase (RTK) signaling is frequently increased in tumor cells, sometimes as a result of decreased receptor down-regulation. The extent to which the endocytic trafficking routes can contribute to such RTK hyperactivation is unclear. Here, we show for the first time that fibroblast transformation by H-RasG12V induces the internalization of platelet-derived growth factor β-receptor (PDGFRβ) by macropinocytosis, enhancing its signaling activity and increasing anchorage-independent proliferation. H-RasG12V transformation and PDGFRβ activation were synergistic in stimulating phosphatidylinositol (PI) 3-kinase activity, leading to receptor macropinocytosis. PDGFRβ macropinocytosis was both necessary and sufficient for enhanced receptor activation. Blocking macropinocytosis by inhibition of PI 3-kinase prevented the increase in receptor activity in transformed cells. Conversely, increasing macropinocytosis by Rabankyrin-5 overexpression was sufficient to enhance PDGFRβ activation in nontransformed cells. Simultaneous stimulation with PDGF-BB and epidermal growth factor promoted macropinocytosis of both receptors and increased their activation in nontransformed cells. We propose that H-Ras transformation promotes tumor progression by enhancing growth factor receptor signaling as a result of increased receptor macropinocytosis.
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Affiliation(s)
- C Schmees
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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2
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Holmgren L. Potential Dual Roles of PDGF-B during Human Placental Blood Vessel Formation. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10623329309102693] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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3
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Jandt E, Denner K, Kovalenko M, Ostman A, Böhmer FD. The protein-tyrosine phosphatase DEP-1 modulates growth factor-stimulated cell migration and cell-matrix adhesion. Oncogene 2003; 22:4175-85. [PMID: 12833140 DOI: 10.1038/sj.onc.1206652] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Density-enhanced protein-tyrosine phosphatase-1 (DEP-1 also CD148) is a transmembrane molecule with a single intracellular PTP domain. It has recently been proposed to function as a tumor suppressor. We have previously shown that DEP-1 dephosphorylates the activated platelet-derived growth factor (PDGF) beta-receptor in a site-selective manner (Kovalenko et al. (2000). J. Biol. Chem. 275, 16219-16226). We analysed cell lines with inducible DEP-1 expression for cellular functions of DEP-1. Several aspects of PDGFbeta-receptor signaling were negatively affected by DEP-1 expression. These include PDGF-stimulated activation of inositol trisphosphate formation, Erk1/2, p21Ras, and Src. Activation of receptor-associated phosphoinositide-3 kinase activity and of Akt/PKB were weakly attenuated at early time points of stimulation. Inhibition of PDGF-stimulated signaling depended on DEP-1 catalytic activity. Importantly, DEP-1 inhibited PDGF-stimulated cell migration. The catalytically inactive DEP-1 C1239S variant enhanced cell migration and PDGF-stimulated Erk1/2 activation, suggesting a dominant negative interference with endogenous DEP-1. In contrast to cell migration, cell-substrate adhesion was promoted by active DEP-1 and delayed or suppressed by DEP-1 C1239S, correlating with positive effects of DEP-1 on adhesion-stimulated Src kinase. We propose that negative regulation of growth-factor stimulated cell migration and promotion of cell-matrix adhesion may be related to the function of DEP-1 as tumor suppressor.
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Affiliation(s)
- Enrico Jandt
- Research Unit Molecular Cell Biology, Medical Faculty, Friedrich Schiller University, Drackendorfer str 1, D-07747 Jena, Germany
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4
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Cao R, Bråkenhielm E, Li X, Pietras K, Widenfalk J, Ostman A, Eriksson U, Cao Y. Angiogenesis stimulated by PDGF-CC, a novel member in the PDGF family, involves activation of PDGFR-alphaalpha and -alphabeta receptors. FASEB J 2002; 16:1575-83. [PMID: 12374780 DOI: 10.1096/fj.02-0319com] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A newly discovered PDGF isoform, PDGF-CC, is expressed in actively angiogenic tissues such as placenta, some embryonic tissues, and tumors. We test the possibility that PDGF-CC promotes angiogenesis in vivo. The core domain (mature form) of human PDGF-CC is sufficiently potent to stimulate neovascularization in the mouse cornea. The corneal angiogenic response induced by PDGF-CC is robust although the area of neovascularization is smaller than those of FGF-2- and VEGF-stimulated angiogenesis. Similarly, PDGF-BB and PDGF-AB induce angiogenic responses virtually indistinguishable from PDGF-CC-stimulated vessels. In contrast, PDGF-AA displays only a weak angiogenic response in the mouse cornea. Although there was no significant difference in incorporation of mural cells to the newly formed blood vessels induced by PDGF-BB and -CC, the percentage of mural cell positive vessels induced by PDGF-AA was greater than those induced by FGF-2, PDGF-BB, and PDGF-CC. In the developing chick embryo, PDGF-CC induced branch sprouts from established blood vessels. In PDGF receptor-transfected endothelial cells, PDGF-CC activated the PDGF receptor alpha subunit (PDGFR-alpha). PDGF-CC, but not PDGF-AA, was able to activate PDGFR-beta receptor in endothelial cells that coexpress both alpha and beta forms of receptors. Thus, the PDGF-CC-mediated angiogenic response is most likely transduced by PDGF-alphaalpha and -alphabeta receptors. These data demonstrate that the PDGF family is a complex and important group of proangiogenic factors.
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MESH Headings
- Allantois/blood supply
- Allantois/drug effects
- Animals
- Blood Vessels/drug effects
- Blood Vessels/metabolism
- Chick Embryo
- Chorion/blood supply
- Chorion/drug effects
- Cornea/blood supply
- Cornea/drug effects
- Cornea/metabolism
- Endothelial Growth Factors/pharmacology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Gene Expression
- Humans
- Immunohistochemistry
- Intercellular Signaling Peptides and Proteins/pharmacology
- Lymphokines/pharmacology
- Male
- Mice
- Mice, Inbred C57BL
- Neovascularization, Pathologic/chemically induced
- Neovascularization, Pathologic/metabolism
- Phosphorylation/drug effects
- Platelet Endothelial Cell Adhesion Molecule-1/analysis
- Platelet-Derived Growth Factor/metabolism
- Platelet-Derived Growth Factor/pharmacology
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Platelet-Derived Growth Factor alpha/genetics
- Receptor, Platelet-Derived Growth Factor alpha/metabolism
- Tyrosine/metabolism
- Vascular Endothelial Growth Factor A
- Vascular Endothelial Growth Factors
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Affiliation(s)
- Renhai Cao
- Microbiology and Tumor Biology Center, Karolinska Institute, S-171 77 Stockholm, Sweden
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5
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Kovalenko M, Denner K, Sandström J, Persson C, Gross S, Jandt E, Vilella R, Böhmer F, Ostman A. Site-selective dephosphorylation of the platelet-derived growth factor beta-receptor by the receptor-like protein-tyrosine phosphatase DEP-1. J Biol Chem 2000; 275:16219-26. [PMID: 10821867 DOI: 10.1074/jbc.275.21.16219] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ligand stimulation of PDGF beta-receptors leads to autophosphorylation of the regulatory tyrosine 857 and of tyrosine residues that in their phosphorylated form serve as docking sites for Src homology 2 domain-containing proteins. Regulation of the PDGF beta-receptor by protein-tyrosine phosphatases is poorly understood. We have investigated PDGF beta-receptor dephosphorylation by receptor-like protein-tyrosine phosphatase DEP-1 using a cell line with inducible DEP-1 expression and by characterizing in vitro dephosphorylation of the PDGF beta-receptor and of receptor-derived phosphopeptides by DEP-1. After DEP-1 induction PDGF beta-receptor.DEP-1 complexes and reduced receptor tyrosine phosphorylation were observed. Phosphopeptide analysis of the PDGF beta-receptors from DEP-1-expressing cells and of the receptors dephosphorylated in vitro by DEP-1 demonstrated that dephosphorylation of autophosphorylation sites of the receptor differed and revealed that the regulatory Tyr(P)(857) was not a preferred site for DEP-1 dephosphorylation. When dephosphorylation of synthetic receptor-derived peptides was analyzed, the selectivity was reproduced, indicating that amino acid sequence surrounding the phosphorylation sites is the major determinant of selectivity. This notion is supported by the observation that the poorly dephosphorylated Tyr(P)(562) and Tyr(P)(857), in contrast to other analyzed phosphorylation sites, are surrounded by basic amino acid residues at positions -4 and +3 relative to the tyrosine residue. Our study demonstrates that DEP-1 dephosphorylation of the PDGF beta-receptor is site-selective and may lead to modulation, rather than general attenuation, of signaling.
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Affiliation(s)
- M Kovalenko
- Ludwig Institute for Cancer Research, Box 595, S-751 24, Uppsala, Sweden
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6
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Hussain AM, Chang CF. Novel kinetics, behaviour and cell-type specificity of CD157-mediated tyrosine kinase signalling. Cell Signal 1999; 11:891-7. [PMID: 10659997 DOI: 10.1016/s0898-6568(99)00057-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CD157, a recently characterized leukocyte surface antigen, has recently been shown to induce tyrosine phosphorylation of a 130-kDa protein (p130) when cross-linked with its antibody (ligand). We have further investigated the detailed kinetics, behaviour and cell-type specificity of this CD157-stimulated p130 phosphorylation. We demonstrate that CD157-mediated p130 phosphorylation is ligand independent in recombinant CD157-expressing CHO, MCA102 and COS-7 cells but is ligand dependent in HL-60-differentiated monocytes (mHL-60) having enhanced CD157 expression. This p130 phosphorylation is activated only at lower temperatures (0-4 degrees C) in MCA102, COS-7 and mHL-60 cells but is temperature insensitive in CHO cells. We further demonstrate that the CHO/CD157 cell clones have approximately 22-28% slower rates of proliferation than that of a CHO/mock clone. But the MCA102 cell proliferation remains unaffected by CD157 expression. We postulate that the difference in the temperature sensitivity of p130 phosphorylation can be responsible for the discrepancy in the rates of MCA102/CD157 and CHO/CD157 cell proliferation.
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Affiliation(s)
- A M Hussain
- Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore
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7
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Rajkumar VS, Sundberg C, Abraham DJ, Rubin K, Black CM. Activation of microvascular pericytes in autoimmune Raynaud's phenomenon and systemic sclerosis. ARTHRITIS AND RHEUMATISM 1999; 42:930-41. [PMID: 10323448 DOI: 10.1002/1529-0131(199905)42:5<930::aid-anr11>3.0.co;2-1] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To determine the temporal and spatial relationship between platelet-derived growth factor beta (PDGFbeta) receptors, PDGF-AB/BB, and activated pericytes across the Raynaud's phenomenon (RP) and systemic sclerosis (SSc; scleroderma) disease spectrum. METHODS Monoclonal antibodies against PDGFbeta receptors, PDGF-AB/BB, and high molecular weight-melanoma-associated antigen (HMW-MAA), a marker for activated pericytes, were used to immunohistochemically analyze serial sections of skin biopsy tissue from patients with RP and from scleroderma patients. To delineate cell-specific PDGFbeta receptor expression, double immunofluorescence-stained sections were analyzed using computer-aided image analysis and confocal microscopy. RESULTS PDGFbeta receptor-expressing cells and HMW-MAA-expressing pericytes were found in biopsy samples from autoimmune RP patients and in both early fibrotic and early nonfibrotic scleroderma skin, but not in normal or primary RP or late-stage scleroderma skin. PDGF-AB/BB was expressed within the epidermis, at the epidermal/dermal junction, and by dermal macrophages. Analysis of juxtaposed serial sections revealed an increased frequency of receptor expression in microvessels from autoimmune RP and early scleroderma skin (P < 0.01). Double-labeling studies using confocal microscopy showed that, in vivo, PDGFbeta receptors were predominantly expressed by microvascular pericytes from both autoimmune RP and early scleroderma skin. CONCLUSION PDGFbeta receptors are expressed by activated microvascular pericytes in patients with autoimmune RP and in early SSc patients, but not in those with primary RP or late-stage scleroderma. These findings suggest that features of autoimmune RP are distinct from those of primary RP, and that microvascular pericytes may be an important link between chronic microvascular damage and fibrosis.
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8
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Wiseman PW, Petersen NO. Image correlation spectroscopy. II. Optimization for ultrasensitive detection of preexisting platelet-derived growth factor-beta receptor oligomers on intact cells. Biophys J 1999; 76:963-77. [PMID: 9916027 PMCID: PMC1300045 DOI: 10.1016/s0006-3495(99)77260-7] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Previously we introduced image correlation spectroscopy (ICS) as an imaging analog of fluorescence correlation spectroscopy (FCS). Implementation of ICS with image collection via a standard fluorescence confocal microscope and computer-based autocorrelation analysis was shown to facilitate measurements of absolute number densities and determination of changes in aggregation state for fluorescently labeled macromolecules. In the present work we illustrate how to use ICS to quantify the aggregation state of immunolabeled plasma membrane receptors in an intact cellular milieu, taking into account background fluorescence. We introduce methods that enable us to completely remove white noise contributions from autocorrelation measurements for individual images and illustrate how to perform background corrections for autofluorescence and nonspecific fluorescence on cell population means obtained via ICS. The utilization of photon counting confocal imaging with ICS analysis in combination with the background correction techniques outlined enabled us to achieve very low detection limits with standard immunolabeling methods on normal, nontransformed human fibroblasts (AG1523) expressing relatively low numbers of platelet-derived growth factor-beta (PDGF-beta) receptors. Specifically, we determined that the PDGF-beta receptors were preaggregated as tetramers on average with a mean surface density of 2.3 clusters micrometer(-2) after immunolabeling at 4 degreesC. These measurements, which show preclustering of PDGF-beta receptors on the surface of normal human fibroblasts, contradict a fundamental assumption of the ligand-induced dimerization model for signal transduction and provide support for an alternative model that posits signal transduction from within preexisting receptor aggregates.
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Affiliation(s)
- P W Wiseman
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
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9
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Zaman GJ, Vink PM, van den Doelen AA, Veeneman GH, Theunissen HJ. Tyrosine kinase activity of purified recombinant cytoplasmic domain of platelet-derived growth factor beta-receptor (beta-PDGFR) and discovery of a novel inhibitor of receptor tyrosine kinases. Biochem Pharmacol 1999; 57:57-64. [PMID: 9920285 DOI: 10.1016/s0006-2952(98)00271-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Aberrant expression of platelet-derived growth factor and its receptor (PDGFR) has been implicated in various human disorders, including cardiovascular disease and certain types of cancer. Inhibitors of the tyrosine kinase activity of PDGFR are leads in the development of novel agents to combat these diseases. We describe here a novel, potent inhibitor of PDGFR tyrosine kinase, 3-(4-dimethylamino-benzylidenyl)-2-indolinone (DMBI). The compound also inhibits signal transduction through fibroblast growth factor receptor 1 (FGFR1), but is not active towards epidermal growth factor receptor (EGFR) or c-Src tyrosine kinase. The activity of DMBI and other tyrosine kinase inhibitors was compared in a cell-based assay as well as in an assay based on purified recombinant platelet-derived growth factor beta-receptor (beta-PDGFR) lacking the transmembrane and ligand-binding domain. We showed that this truncated beta-PDGFR could dimerize, and that dimerization was required for tyrosine kinase activity. Tyrosine kinase activity was modulated by inhibitors of beta-PDGFR autophosphorylation in cells, but not by specific inhibitors of EGFR or c-Src tyrosine kinase. We conclude that beta-PDGFR lacking the transmembrane and ligand-binding domain retains the essential properties of the full-length receptor tyrosine kinase.
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Affiliation(s)
- G J Zaman
- N.V. Organon, Scientific Development Group, Oss, The Netherlands
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10
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Hansen K, Rönnstrand L, Claesson-Welsh L, Heldin CH. Phosphorylation of a 72-kDa protein in PDGF-stimulated cells which forms complex with c-Crk, c-Fyn and Eps15. FEBS Lett 1997; 409:195-200. [PMID: 9202144 DOI: 10.1016/s0014-5793(97)00495-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ligand-induced activation of the beta-receptor for platelet-derived growth factor (PDGF) induces tyrosine phosphorylation of a number of downstream signaling proteins. In the present study, we used two-dimensional gel electrophoresis to characterize the spectrum of proteins phosphorylated in response to PDGF stimulation in porcine aortic endothelial cells expressing PDGF beta-receptors. Several previously known substrates for the PDGF beta-receptor were identified as well as a novel substrate of 72 kDa. The 72-kDa component could be co-immunoprecipitated in complex with the adaptor protein c-Crk, the non-receptor tyrosine kinase c-Fyn and the signaling molecule Eps15. The results obtained suggests that the 72-kDa protein might play an important role in signaling via the PDGF beta-receptor, coupling non-receptor tyrosine kinases of the Src family with c-Crk and Eps15.
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Affiliation(s)
- K Hansen
- Ludwig Institute for Cancer Research, Uppsala, Sweden
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11
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Wang JL, Nistér M, Bongcam-Rudloff E, Pontén J, Westermark B. Suppression of platelet-derived growth factor alpha- and beta-receptor mRNA levels in human fibroblasts by SV40 T/t antigen. J Cell Physiol 1996; 166:12-21. [PMID: 8557760 DOI: 10.1002/(sici)1097-4652(199601)166:1<12::aid-jcp2>3.0.co;2-j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
It is known that down-regulation of cell surface platelet-derived growth factor (PDGF) receptors accompanies transformation by SV40. In this work human embryonic lung fibroblasts were used as a model system to study the effects of SV 40 on PDGF receptor expression. It is shown that transformation by SV 40 early region leads to a total loss of PDGF alpha-receptor and partial loss of beta-receptor mRNA. Microinjection experiments revealed that receptor down-regulation was a primary effect, and not only secondary to transformation and clonal selection. Total loss of PDGF alpha-receptor expression requires both large T and small t, and down-regulation of the PDGF alpha-receptor occurs independently of p53 and Rb binding to large T.
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Affiliation(s)
- J L Wang
- Department of Pathology, University Hospital, Uppsala, Sweden
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12
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Ljung A, Skoog V, Widenfalk B, Ren Z, Nistér M, Ohlsén L. Expression of platelet-derived growth factor beta receptor in chondrogenesis of perichondrial transplants. SCANDINAVIAN JOURNAL OF PLASTIC AND RECONSTRUCTIVE SURGERY AND HAND SURGERY 1995; 29:289-95. [PMID: 8771254 DOI: 10.3109/02844319509008962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
An experimental study was done in two rabbits to establish whether the early stages of cartilage generation involves stimulation via the platelet-derived growth factor beta receptor (PDGFR-beta). Rib perichondrium was dissected off and transplanted to the knee joint. The perichondrial grafts were removed for microscopic investigation at day 0 and day 6 and kept frozen until analysed by immunohistochemistry and in situ hybridisation for the presence of PDGF beta receptor protein and mRNA, respectively. Samples from day 0 showed sparse cells with a positive immunohistochemical reaction. In samples from day 6 there were signs of perichondrial proliferation and chondroid maturation and a more widespread immunohistochemical staining reaction could be seen mainly on proliferating perichondrial cells, but also on some chondrocytes. In situ hybridisation confirmed the expression of PDGF beta receptor mRNA in the same areas of serial sections. These findings may indicate that PDGF beta receptor activity is part of the early response after autotransplantation of perichondrium.
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Affiliation(s)
- A Ljung
- Department of Plastic and Hand Surgery, University Hospital, Uppsala, Sweden
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13
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Obermeier A, Bradshaw RA, Seedorf K, Choidas A, Schlessinger J, Ullrich A. Definition of signals for neuronal differentiation. Ann N Y Acad Sci 1995; 766:1-17. [PMID: 7486648 DOI: 10.1111/j.1749-6632.1995.tb26643.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- A Obermeier
- Department of Molecular Biology, Max-Planck-Institut für Biochemie, Martinsried, Germany
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14
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Lindmark G, Gerdin B, Påhlman L, Bergström R, Glimelius B. Prognostic predictors in colorectal cancer. Dis Colon Rectum 1994; 37:1219-27. [PMID: 7995147 DOI: 10.1007/bf02257785] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE Better prognostic predictors in colorectal cancer than the Dukes stage are necessary for individualized therapy and follow-up. METHODS Survival among 212 patients operated on for colorectal cancer was examined regarding various clinical, histopathologic, cellular, and serologic tumor characteristics. RESULTS Beside the Dukes stage, which was the most powerful variable, the erythrocyte sedimentation rate, leukocyte blood count, alkaline phosphatase, aspartate aminotransferase, six different serum tumor markers, number of small blood vessels, and age were found to be significantly associated with survival. The leukocyte blood count, alkaline phosphatase, and aspartate aminotransferase retained their significance in a multivariate model including tumor differentiation, local tumor stage, and age. Inclusion of tissue polypeptide antigen, the most powerful tumor marker in the multivariate model, showed that only the tumor stage, tissue polypeptide antigen, and age were statistically significantly correlated to survival. This was valid both for the group of patients considered as potentially curable and for those who potentially have been cured (Dukes Stages A-C). CONCLUSIONS A great number of prognostic predictors failed to discard Dukes stage as the best one. One serum tumor marker, tissue polypeptide antigen, contains independent additional prognostic information.
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15
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Inui H, Kitami Y, Tani M, Kondo T, Inagami T. Differences in signal transduction between platelet-derived growth factor (PDGF) alpha and beta receptors in vascular smooth muscle cells. PDGF-BB is a potent mitogen, but PDGF-AA promotes only protein synthesis without activation of DNA synthesis. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)43848-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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16
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Simpson DG, Terracio L, Terracio M, Price RL, Turner DC, Borg TK. Modulation of cardiac myocyte phenotype in vitro by the composition and orientation of the extracellular matrix. J Cell Physiol 1994; 161:89-105. [PMID: 7929612 DOI: 10.1002/jcp.1041610112] [Citation(s) in RCA: 145] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cellular phenotype is the result of a dynamic interaction between a cell's intrinsic genetic program and the morphogenetic signals that serve to modulate the extent to which that program is expressed. In the present study we have examined how morphogenetic information might be stored in the extracellular matrix (ECM) and communicated to the neonatal heart cell (NHC) by the cardiac alpha 1 beta 1 integrin molecule. A thin film of type I collagen (T1C) was prepared with a defined orientation. This was achieved by applying T1C to the peripheral edge of a 100 mm culture dish. The T1C was then drawn across the surface of the dish in a continuous stroke with a sterile cell scraper and allowed to polymerize. When NHCs were cultured on this substrate, they spread, as a population, along a common axis in parallel with the gel lattice and expressed an in vivo-like phenotype. Individual NHCs displayed an elongated, rod-like shape and disclosed parallel arrays of myofibrils. These phenotypic characteristics were maintained for at least 4 weeks in primary culture. The evolution of this tissue-like organizational pattern was dependent upon specific interactions between the NHCs and the collagen-based matrix that were mediated by the cardiac alpha 1 beta 1 integrin complex. This conclusion was supported by a variety of experimental results. Altering the tertiary structure of the matrix or blocking the extracellular domains of either the cardiac alpha 1 or beta 1 integrin chain inhibited the expression of the tissue-like pattern of organization. Neither cell-to-cell contact or contractile function were necessary to induce the formation of the rod-like cell shape. However, beating activity was necessary for the assembly of a well-differentiated myofibrillar apparatus. These data suggest that the cardiac alpha 1 beta 1 integrin complex serves to detect and transduce phenotypic information stored within the tertiary structure of the surrounding matrix.
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Affiliation(s)
- D G Simpson
- Department of Developmental Biology and Anatomy, University of South Carolina Medical School, Columbia 29208
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17
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Pontén F, Ren Z, Nistér M, Westermark B, Pontén J. Epithelial-stromal interactions in basal cell cancer: the PDGF system. J Invest Dermatol 1994; 102:304-9. [PMID: 8120413 DOI: 10.1111/1523-1747.ep12371787] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A proposed progenitor cell for basal cell carcinoma is a stem cell located in the bulge of the hair follicle. Previous investigations have shown that basal cell carcinoma has a specific stroma requirement for its growth. Likewise the development of a normal hair follicle requires the inductive force of a specialized structure with condensed mesenchyme that eventually forms the dermal hair papilla. Investigations in mouse embryos also strongly indicate that induction/growth of skin structures is dependent on platelet-derived growth factor (PDGF) alpha-receptor expression in the mesenchyme. We therefore investigated the expression of PDGF A and B chain and PDGF alpha and beta receptors in basal cell carcinoma and in normal skin by immunohistochemistry and in situ hybridization. alpha and beta receptors were found in the specific stroma components of basal cell carcinoma, dermal hair papilla, and sweat glands, but not in the epithelial structures. The A and B chains, on the other hand, were mainly found in basal cell carcinoma cells, in hair matrix, and in sweat gland epithelium. This "appositional" expression of PDGF/PDGF receptor closely resembles that found in epithelial/mesenchymal structures during normal development. The findings also suggest that PDGF receptor expression is one of the characteristics of the specific stroma that is necessary for basal cell carcinoma growth.
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Affiliation(s)
- F Pontén
- Department of Pathology, University Hospital, Uppsala, Sweden
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18
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Joly M, Kazlauskas A, Fay FS, Corvera S. Disruption of PDGF receptor trafficking by mutation of its PI-3 kinase binding sites. Science 1994; 263:684-7. [PMID: 8303278 DOI: 10.1126/science.8303278] [Citation(s) in RCA: 249] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Human platelet-derived growth factor receptors (PDGFRs) expressed in human Hep G2 cells internalized and concentrated in a juxtanuclear region near the Golgi network within 10 minutes after the cells were treated with PDGF. A PDGFR mutant (F5) that lacks high-affinity binding sites for the Src homology 2 domain-containing proteins phosphatidylinositol-3 kinase (PI-3 kinase), Ras guanosine triphosphatase activating protein, phospholipase C-gamma, and a phosphotyrosine phosphatase (Syp) remained at the cell periphery. Restoration of the PI-3 kinase binding sites on F5 completely restored the ability of the receptor to concentrate intracellularly. A PDGFR mutant lacking only PI-3 kinase binding sites failed to concentrate intracellularly. Thus, PI-3 kinase binding sites appear both necessary and sufficient for the normal endocytic trafficking of the activated PDGFR.
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Affiliation(s)
- M Joly
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester 01605
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19
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Sorkin A, Eriksson A, Heldin CH, Westermark B, Claesson-Welsh L. Pool of ligand-bound platelet-derived growth factor beta-receptors remain activated and tyrosine phosphorylated after internalization. J Cell Physiol 1993; 156:373-82. [PMID: 7688373 DOI: 10.1002/jcp.1041560221] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have examined the state of tyrosine phosphorylation of ligand-bound, internalized platelet-derived growth factor (PDGF) beta-receptors. Analysis by immunofluorescence staining of cells stimulated with PDGF-BB at 37 degrees C indicated colocalization of phosphotyrosine, PDGF beta-receptors, and PDGF-BB in endosome-like vesicles. Treatment of cells with an acidic buffer, which removed cell surface-bound PDGF-BB, led to a considerable decrease in phosphorylation and kinase activity of cell surface localized PDGF beta-receptors, but not of internalized receptors. Immunoprecipitations using antisera against phosphotyrosine and the PDGF beta-receptor from metabolically labeled cells showed that a major fraction of the tyrosine-phosphorylated pool of receptors were still accessible to the acid buffer treatment after 10 min of incubation of the cells at 37 degrees C. Under these conditions, about 20-25% of the total pool of tyrosine-phosphorylated receptors were intracellular, since they remained tyrosine phosphorylated after the acid buffer treatment. A considerable pool of tyrosine-phosphorylated, internalized receptors, after 10 min of incubation of the cells at 37 degrees C, could also be detected by immunoblotting analysis, using antisera against the PDGF beta-receptor and phosphotyrosine. Analysis by in vitro kinase assays of immunoprecipitated PDGF beta-receptors, obtained from PDGF-BB-stimulated cells different times after acid wash, showed that the internalized receptors retained kinase activity. These data suggest that a pool of internalized PDGF beta-receptors remain active and may participate in signalling a considerable time after internalization.
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Affiliation(s)
- A Sorkin
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146
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20
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Bryckaert MC, Eldor A, Fontenay M, Gazit A, Osherov N, Gilon C, Levitzki A, Tobelem G. Inhibition of platelet-derived growth factor-induced mitogenesis and tyrosine kinase activity in cultured bone marrow fibroblasts by tyrphostins. Exp Cell Res 1992; 199:255-61. [PMID: 1312007 DOI: 10.1016/0014-4827(92)90432-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Tyrphostins, which block protein tyrosine kinase activity, were studied for their inhibitory action on platelet-derived growth factor (PDGF)-induced proliferation of human bone marrow fibroblasts. Of the seven tryphostins examined, tyrphostin AG370 was found to be the most potent blocker against PDGF-induced mitogenesis (IC50 = 20 microM). This PTK blocker also blocks mitogenesis induced by epidermal growth factor (IC50 = 50 microM) and human serum (IC50 = 50 microM), but with lower efficacy. In digitonin-permeabilized fibroblasts as well as in intact fibroblasts, tyrphostin AG370 inhibits PDGF receptor autophosphorylation and the tyrosine phosphorylation of intracellular protein substrates (pp120, pp85, and pp75) which coprecipitate with the PDGF receptor. In comparison to AG370, AG18, a potent EGF receptor blocker, was less efficient in inhibiting PDGF-induced proliferation of fibroblasts and phosphorylation of the intracellular protein substrates. Under the conditions in which AG370 inhibits PDGF-induced mitogenesis and phosphorylation, it does not affect [125I]PDGF internalization and enhance [125I]PDGF binding. These findings suggest that AG370, which is an indole tyrphostin, may serve as a model for developing analogues with a therapeutic potential for treatment of diseases which involve abnormal cellular proliferation induced by PDGF.
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21
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Lee AW. Signal transduction by the colony-stimulating factor-1 receptor; comparison to other receptor tyrosine kinases. CURRENT TOPICS IN CELLULAR REGULATION 1992; 32:73-181. [PMID: 1318184 DOI: 10.1016/b978-0-12-152832-4.50005-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- A W Lee
- Clinical Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892
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22
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Eriksson A, Rorsman C, Ernlund A, Claesson-Welsh L, Heldin CH. Ligand-induced homo- and hetero-dimerization of platelet-derived growth factor alpha- and beta-receptors in intact cells. Growth Factors 1992; 6:1-14. [PMID: 1317195 DOI: 10.3109/08977199209008867] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Porcine aortic endothelial cells expressing platelet-derived growth factor (PDGF) alpha- or beta-receptors after transfection of the corresponding cDNAs, were used to investigate whether PDGF receptor dimerization occurs in intact cells after ligand binding. Using three different methods--covalent cross-linking of 125I-labeled ligand, cross-linking of metabolically labeled cells after ligand-binding followed by immunoprecipitation, and immunoblotting of cells after ligand binding and cross-linking--it was demonstrated that alpha- as well as beta-receptors form ligand-induced dimeric complexes. Dimerization correlated with induction of receptor kinase activity, measured as receptor autophosphorylation. Heterodimeric complexes could furthermore be induced by PDGF-AB, when added to a mixture of lysates from the alpha- and beta-receptor expressing cell lines, or when added to human fibroblasts which express both receptor types.
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Affiliation(s)
- A Eriksson
- Ludwig Institute for Cancer Research, Uppsala, Sweden
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23
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Holmgren L, Claesson-Welsh L, Heldin CH, Ohlsson R. The expression of PDGF alpha- and beta-receptors in subpopulations of PDGF-producing cells implicates autocrine stimulatory loops in the control of proliferation in cytotrophoblasts that have invaded the maternal endometrium. Growth Factors 1992; 6:219-31. [PMID: 1389228 DOI: 10.3109/08977199209026929] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to explain the high proliferative potential of human placental cytotrophoblasts, we have addressed the potential involvement of platelet-derived growth factor (PDGF) ligand and receptors. Although PDGF is usually described as a mitogen for cells of mesenchymal origin, we show in this report that extra-villous term placental cytotrophoblasts express the PDGF alpha- and beta-receptor genes, both in vivo and in vitro. In addition, cytotrophoblasts produce significant amounts of PDGF-B protein. By immunohistochemical analysis of receptor expression, we found that the PDGF alpha-receptors could be detected at the cell surface, while the PDGF beta-receptors were only detected intracellularly. In addition, double immunostaining analysis showed that the PDGF alpha- and beta-receptor molecules are expressed in different subpopulations of cytotrophoblasts. The addition of PDGF-AA and PDGF-BB homodimers to cytotrophoblast primary cultures induced a significant increase in DNA synthesis. We conclude, therefore, that PDGF is a growth factor for placental cytotrophoblasts and suggest that the growth of cytotrophoblasts can partly be explained by a PDGF autostimulatory loop, limited by the number of receptor-positive cytotrophoblasts.
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Affiliation(s)
- L Holmgren
- Laboratory for Molecular Development and Tumour Biology, Institute of Experimental Drug Research, Karolinska Hospital, Stockholm, Sweden
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Ljungquist-Höddelius P, Lirvall M, Wasteson A, Magnusson KE. Lateral diffusion of PDGF beta-receptors in human fibroblasts. Biosci Rep 1991; 11:43-52. [PMID: 1650612 DOI: 10.1007/bf01118604] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
When platelet-derived growth factor (PDGF) binds to its receptors a number of biochemical reactions are elicited in the cell. Several models have been presented for the effects of ligand-induced receptor conformation and aggregation on signal transduction but little is known about the direct effects on receptor diffusion. This study concerns the lateral mobility of PDGF receptors in fibroblasts. It was assessed with fluorescence recovery after photobleaching (FRAP), using rhodaminated receptor antibodies or Fab-fragments of the antibody as ligands. The aims of the investigation were: (a) to compare the lateral mobility of membrane receptors of human fibroblasts labelled with either antibodies against the PDGF receptor or Fab-fragments of the same antibodies, and (b) to study the effects of serum or PDGF on the mobility of the receptors. Human foreskin fibroblasts (AG 1523) were grown on coverslips either under standard or under serum-free conditions yielding "normal" and "starved" cells, respectively. Two parameters of the diffusion were evaluated; the diffusion coefficient (D) and the mobile fraction (R) of the receptors. We found that normal fibroblasts had a smaller diffusion coefficient and a lower mobile fraction compared to starved cells using antibodies for receptor labelling. The addition of PDGF, just before the measurement, increased the D and R for normal cells, while starved cells, showing higher initial values, displayed slightly reduced values of D and R. After the addition of serum, D increased and R remained low for normal cells, whereas for starved cells both D and R increased to upper limits of 11.0 x 10(-10) cm2s-1 and greater than 90% respectively. In general, the D and R values, both in normal and starved cells, were higher for cells labelled with Fab-fragments than for antibody-labelled cells. The results are discussed in relation to the natural complexity of the receptor, and how PDGF, serum, antibodies and Fab-fragments might interfere with receptor structure, aggregation state and membrane diffusion characteristics.
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Wang JL, Nistér M, Hermansson M, Westermark B, Pontén J. Expression of PDGF beta-receptors in human meningioma cells. Int J Cancer 1990; 46:772-8. [PMID: 1699901 DOI: 10.1002/ijc.2910460504] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Meningioma is a generally benign tumor derived from arachnoid tissue. We have investigated the presence of functionally active PDGF-receptors on human meningioma cells in culture. Tumor samples were obtained from 3 surgically removed benign meningiomas and normal arachnoid tissue from an autopsy case. Binding studies were performed by using 125I-labelled recombinant PDGF-AA and PDGF-BB. Only 125I-PDGF-BB showed specific binding to all tumor-cell cultures after incubation of cells for 2 hr at 4 degrees C. Effects of PDGF-AA and PDGF-BB on DNA synthesis were measured as 3H-thymidine incorporation during 48 hr of labelling cells maintained in Eagle's minimum essential medium 0.5% fetal calf serum. PDGF-BB but not PDGF-AA stimulated DNA synthesis in all 3 tumor-cell cultures. Total cellular RNA was analyzed by Northern blotting and hybridization with a 32P-labelled human PDGF beta-receptor probe, and PDGF beta-receptor mRNA was found in both tumor and arachnoid cell cultures. Furthermore, PDGF beta-receptor mRNA was shown to be present in 2 meningioma biopsies and immunohistochemical staining revealed that PDGF beta-receptors are present in meningioma and arachnoid tissues in vivo. It appears that a possible way of maintaining human meningioma cell growth in vivo is through activation of PDGF beta-receptors.
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Affiliation(s)
- J L Wang
- Department of Pathology, University Hospital, Uppsala, Sweden
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Klareskog L, Gustafsson R, Scheynius A, Hällgren R. Increased expression of platelet-derived growth factor type B receptors in the skin of patients with systemic sclerosis. ARTHRITIS AND RHEUMATISM 1990; 33:1534-41. [PMID: 2171541 DOI: 10.1002/art.1780331011] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The expression of B-type receptors for platelet-derived growth factor (PDGF) was investigated in skin biopsy samples from patients with systemic sclerosis (SSc), by immunohistochemical staining using monoclonal antibodies specific for the receptor. Whereas skin from healthy individuals lacked expression of PDGF-B receptors, receptor expression was seen in sclerodermatous skin lesions from 13 of 14 patients. Increased receptor expression was observed in dermal vessels, as well as on many stromal fibroblast-like cells close to these vessels. PDGF-B receptor expression was most pronounced within and around dermal vessels in which perivascular infiltrates of Leu-4-positive T lymphocytes and HLA-DR-positive, RFD7-positive activated macrophages were present. Both perivascular inflammatory cell infiltrates and PDGF-B receptor expression were generally also seen in macroscopically normal areas of the skin of the SSc patients, indicating that the observed phenotypic alterations may precede the macroscopically observable features of scleroderma in the skin. The observed induction of PDGF-B receptors, together with indirect indications of increased synthesis and release of PDGF, would be compatible with altered PDGF-mediated control of connective tissue cell growth as part of the molecular basis for development of the skin lesions in SSc.
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Affiliation(s)
- L Klareskog
- Department of Internal Medicine, University Hospital, Uppsala, Sweden
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Fellström B, Klareskog L, Heldin CH, Larsson E, Rönnstrand L, Terracio L, Tufveson G, Wahlberg J, Rubin K. Platelet-derived growth factor receptors in the kidney--upregulated expression in inflammation. Kidney Int 1989; 36:1099-102. [PMID: 2557480 DOI: 10.1038/ki.1989.306] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Major features of a long-standing inflammation in the kidney are vascular proliferation, glomerulosclerosis, interstitial fibrosis and tubular atrophy, leading to a gradual deterioration of the renal function. In this study we have investigated the expression of B-type receptors for platelet-derived growth factor (PDGF) in frozen sections from normal and inflamed kidneys. Immunohistochemical techniques, employing two monoclonal antibodies specific for PDGF B-type receptors, were used. The specimens investigated were 15 kidneys removed by transplantectomy because of chronic rejection, 20 cases of glomerulonephritis with crescent formation, mesangial proliferation or non-proliferative glomerulonephritis, and six normal kidneys. In parallel we characterized cellular infiltrates and class II transplantation antigen expression in the inflamed kidneys. An enhanced PDGF receptor expression was found on intimal cells and on smooth muscle cells of the proliferating vessels, on glomerular cells in glomeruli with mesangial proliferation, and on fibroblast-like cells in the proximity of clusters of infiltrating macrophages and T-lymphocytes of the interstitial tissue. Induction of PDGF receptor expression may render cells responsive to stimulation by PDGF, released from PDGF-producing cells, such as activated macrophages and from platelets. Our data suggest that PDGF is involved in the proliferation of mesenchymal cells that is seen in rejected kidney transplants and glomerulonephritis.
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Affiliation(s)
- B Fellström
- Department of Internal Medicine, University of Uppsala, Sweden
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Heldin CH, Ernlund A, Rorsman C, Rönnstrand L. Dimerization of B-type Platelet-derived Growth Factor Receptors Occurs After Ligand Binding and Is Closely Associated with Receptor Kinase Activation. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)81879-8] [Citation(s) in RCA: 235] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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