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1.
J Biol Chem ; 276(2): 1660-4, 2001 Jan 12.
Article in English | MEDLINE | ID: mdl-11058597

ABSTRACT

We report identification of interleukin (IL)-17E, a novel member of the IL-17 family of cytokines. IL-17E is a ligand for the recently identified protein termed EVI27/IL-17BR, which we term IL-17 receptor homolog 1 (IL-17Rh1) in light of the multiple reported ligand-receptor relationships. Murine EVI27 was identified through its location at a common site of retroviral integration in BXH2 murine myeloid leukemias. IL-17Rh1 shows highest level expression in kidney with moderate expression in multiple other organs, whereas IL-17E mRNA was detected at very low levels in several peripheral tissues. IL-17E induces activation of NF-kappaB and stimulates production of the proinflammatory chemokine IL-8.


Subject(s)
Interleukin-17/genetics , Interleukin-17/metabolism , Receptors, Interleukin/metabolism , Recombinant Proteins/metabolism , Amino Acid Sequence , Animals , Cell Line , Conserved Sequence , Female , Gene Library , Humans , Interleukin-17/chemistry , Interleukin-8/biosynthesis , Kidney/immunology , Leukemia, Experimental/immunology , Leukemia, Experimental/virology , Male , Mice , Molecular Sequence Data , NF-kappa B/metabolism , Organ Specificity , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , RNA, Messenger/genetics , Receptors, Interleukin/genetics , Receptors, Interleukin-17 , Recombinant Proteins/genetics , Recombinant Proteins/pharmacology , Sequence Alignment , Sequence Homology, Amino Acid , Transcription, Genetic , Transfection , Virus Integration
2.
J Biol Chem ; 275(40): 31335-9, 2000 Oct 06.
Article in English | MEDLINE | ID: mdl-10875937

ABSTRACT

We report the identification of a novel human cytokine, distantly related to interleukin (IL)-10, which we term IL-22. IL-22 is produced by activated T cells. IL-22 is a ligand for CRF2-4, a member of the class II cytokine receptor family. No high affinity ligand has yet been reported for this receptor, although it has been reported to serve as a second component in IL-10 signaling. A new member of the interferon receptor family, which we term IL-22R, functions as a second component together with CRF2-4 to enable IL-22 signaling. IL-22 does not bind the IL-10R. Cell lines were identified that respond to IL-22 by activation of STATs 1, 3, and 5, but were unresponsive to IL-10. In contrast to IL-10, IL-22 does not inhibit the production of proinflammatory cytokines by monocytes in response to LPS nor does it impact IL-10 function on monocytes, but it has modest inhibitory effects on IL-4 production from Th2 T cells.


Subject(s)
Interleukins/chemistry , Interleukins/metabolism , Membrane Glycoproteins , Receptors, Cytokine/metabolism , Receptors, Interleukin/metabolism , Signal Transduction , Amino Acid Sequence , Blotting, Western , Cell Line , DNA-Binding Proteins/metabolism , Electrophoresis, Polyacrylamide Gel , Enzyme Activation , Enzyme-Linked Immunosorbent Assay , Expressed Sequence Tags , Flow Cytometry , Humans , Interleukin-10/metabolism , Interleukin-10 Receptor beta Subunit , Ligands , Lipopolysaccharides/pharmacology , Molecular Sequence Data , Monocytes/metabolism , Protein Binding , Receptors, Interleukin-10 , Sequence Homology, Amino Acid , T-Lymphocytes/metabolism , Th2 Cells/metabolism , Tumor Necrosis Factor-alpha/metabolism , Interleukin-22
3.
Proc Natl Acad Sci U S A ; 97(2): 773-8, 2000 Jan 18.
Article in English | MEDLINE | ID: mdl-10639155

ABSTRACT

IL-17 is a T cell-derived cytokine that may play an important role in the initiation or maintenance of the proinflammatory response. Whereas expression of IL-17 is restricted to activated T cells, the IL-17 receptor is found to be widely expressed, a finding consistent with the pleiotropic activities of IL-17. We have cloned and expressed two novel human cytokines, IL-17B and IL-17C, that are related to IL-17 ( approximately 27% amino acid identity). IL-17B mRNA is expressed in adult pancreas, small intestine, and stomach, whereas IL-17C mRNA is not detected by RNA blot hybridization of several adult tissues. No expression of IL-17B or IL-17C mRNA is found in activated T cells. In a survey of cytokine induction, IL-17B and IL-17C stimulate the release of tumor necrosis factor alpha and IL-1beta from the monocytic cell line, THP-1, whereas IL-17 has only a weak effect in this system. No induction of IL-1alpha, IL-6, IFN-gamma, or granulocyte colony-stimulating factor is found in THP-1 cells. Fluorescence-activated cell sorter analysis shows that IL-17B and IL-17C bind to THP-1 cells. Conversely, IL-17B and IL-17C are not active in an IL-17 assay or the stimulation of IL-6 release from human fibroblasts and do not bind to the human IL-17 receptor extracellular domain. These data show that there is a family of IL-17-related cytokines differing in patterns of expression and proinflammatory responses that may be transduced through a cognate set of cell surface receptors.


Subject(s)
Interleukin-17/genetics , Amino Acid Sequence , Animals , Cell Line , Chromosome Mapping , Chromosomes, Human, Pair 16/genetics , Chromosomes, Human, Pair 5/genetics , Cloning, Molecular , Cricetinae , Cytokines/genetics , DNA, Complementary/chemistry , DNA, Complementary/genetics , Female , Gene Expression , Humans , Interleukin-1/metabolism , Interleukin-17/metabolism , Interleukin-17/pharmacology , Male , Molecular Sequence Data , Monocytes/drug effects , Monocytes/metabolism , Protein Binding , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Isoforms/pharmacology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Interleukin/metabolism , Receptors, Interleukin-17 , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Tissue Distribution , Tumor Necrosis Factor-alpha/metabolism
4.
Curr Biol ; 9(4): 215-8, 1999 Feb 25.
Article in English | MEDLINE | ID: mdl-10074428

ABSTRACT

The tumor necrosis factor (TNF) and TNF receptor (TNFR) gene superfamilies regulate diverse biological functions, including cell proliferation, differentiation, and survival [1] [2] [3]. We have identified a new TNF-related ligand, designated human GITR ligand (hGITRL), and its human receptor (hGITR), an ortholog of the recently discovered murine glucocorticoid-induced TNFR-related (mGITR) protein [4]. The hGITRL gene mapped to chromosome 1q23, near the gene for the TNF homolog Fas/CD95 ligand [5]. The hGITR gene mapped to chromosome 1p36, near a cluster of five genes encoding TNFR homologs [1] [6]. We found hGITRL mRNA in several peripheral tissues, and detected hGITRL protein on cultured vascular endothelial cells. The levels of hGITR mRNA in tissues were generally low; in peripheral blood T cells, however, antigen-receptor stimulation led to a substantial induction of hGITR transcripts. Cotransfection of hGITRL and hGITR in embryonic kidney 293 cells activated the anti-apoptotic transcription factor NF-kappaB, via a pathway that appeared to involve TNFR-associated factor 2 (TRAF2) [7] and NF-kappaB-inducing kinase (NIK) [8]. Cotransfection of hGITRL and hGITR in Jurkat T leukemia cells inhibited antigen-receptor-induced cell death. Thus, hGITRL and hGITR may modulate T lymphocyte survival in peripheral tissues.


Subject(s)
Chromosomes, Human, Pair 1 , Receptors, Nerve Growth Factor/genetics , Receptors, Tumor Necrosis Factor/genetics , Transcription, Genetic , Tumor Necrosis Factor-alpha/genetics , Amino Acid Sequence , Animals , Cell Line , Cells, Cultured , Chromosome Mapping , Endothelium, Vascular/metabolism , Gene Expression Regulation , Glucocorticoid-Induced TNFR-Related Protein , Humans , Mice , Molecular Sequence Data , Multigene Family , Proteins/metabolism , RNA, Messenger/analysis , Receptors, Nerve Growth Factor/chemistry , Receptors, Nerve Growth Factor/physiology , Receptors, Tumor Necrosis Factor/chemistry , Receptors, Tumor Necrosis Factor/physiology , Recombinant Proteins/biosynthesis , Sequence Alignment , Sequence Homology, Amino Acid , Signal Transduction , TNF Receptor-Associated Factor 2 , Transfection , Tumor Necrosis Factor-alpha/chemistry
5.
Nature ; 395(6699): 284-8, 1998 Sep 17.
Article in English | MEDLINE | ID: mdl-9751057

ABSTRACT

Vertebrates and invertebrates initiate a series of defence mechanisms following infection by Gram-negative bacteria by sensing the presence of lipopolysaccharide (LPS), a major component of the cell wall of the invading pathogen. In humans, monocytes and macrophages respond to LPS by inducing the expression of cytokines, cell-adhesion proteins, and enzymes involved in the production of small proinflammatory mediators. Under pathophysiological conditions, LPS exposure can lead to an often fatal syndrome known as septic shock. Sensitive responses of myeloid cells to LPS require a plasma protein called LPS-binding protein and the glycosylphosphatidylinositol-anchored membrane protein CD14. However, the mechanism by which the LPS signal is transduced across the plasma membrane remains unknown. Here we show that Toll-like receptor 2 (TLR2) is a signalling receptor that is activated by LPS in a response that depends on LPS-binding protein and is enhanced by CD14. A region in the intracellular domain of TLR2 with homology to a portion of the interleukin (IL)-1 receptor that is implicated in the activation of the IL-1-receptor-associated kinase is required for this response. Our results indicate that TLR2 is a direct mediator of signalling by LPS.


Subject(s)
Drosophila Proteins , Lipopolysaccharides/pharmacology , Membrane Glycoproteins/metabolism , Membrane Proteins/metabolism , Receptors, Cell Surface/metabolism , Receptors, Immunologic , Signal Transduction , Binding Sites , Cell Line , Cloning, Molecular , Escherichia coli , Humans , Lipopolysaccharide Receptors/metabolism , Recombinant Proteins/metabolism , Salmonella , Tissue Distribution , Toll-Like Receptor 2 , Toll-Like Receptors , Tumor Cells, Cultured
6.
Cytokine ; 10(1): 19-25, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9505141

ABSTRACT

Cardiotrophin-1 (CT-1), a newly discovered cytokine, has been shown to induce cardiac hypertrophy in vitro and in vivo. The present study examined the effects of CT-1 on haemodynamics and cardiac function. The measurements of haemodynamic parameters were made using in-dwelling catheters and flow probes in conscious, unrestrained rats. Intravenous administration of CT-1 caused a dose-dependent decrease in mean arterial pressure (MAP), and an increase in heart rate (HR). CT-1 (100 micrograms/kg) significantly elevated cardiac output and HR, and decreased MAP and systemic vascular resistance. Stroke volume was unaltered, suggesting that the CT-1 induced increase in cardiac output was secondary to increased HR. There was no significant difference in left ventricular maximal dP/dt between the CT-1-treated and vehicle-treated groups, suggesting that CT-1 might not induce a meaningful change in ventricular contractility. Pretreatment with intravenous N omega-nitro-L-arginine methyl ester, a specific inhibitor of nitric oxide synthase, significantly attenuated the depressor and tachycardic responses to CT-1. These results indicate that nitric oxide plays an important role in mediating the haemodynamic effects of CT-1.


Subject(s)
Cytokines/pharmacology , Heart/drug effects , Hemodynamics/drug effects , Animals , Cardiac Output/drug effects , Heart/physiology , Hypotension/chemically induced , Injections, Intravenous , Male , Nitric Oxide/metabolism , Rats , Rats, Sprague-Dawley , Tachycardia , Ventricular Function, Left/drug effects
7.
Nat Struct Biol ; 5(1): 47-54, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9437429

ABSTRACT

Menkes disease is an X-linked disorder in copper transport that results in death during early childhood. The solution structures of both apo and Ag(I)-bound forms of the fourth metal-binding domain (mbd4) from the Menkes copper-transporting ATPase have been solved. The 72-residue mbd4 has a ferredoxin-like beta alpha beta beta alpha beta fold. Structural differences between the two forms are limited to the metal-binding loop, which is disordered in the apo structure but well ordered in the Ag(I)-bound structure. Ag(I) binds in a linear bicoordinate manner to the two Cys residues of the conserved GMTCxxC motif; Cu(I) likely coordinates in a similar manner. Menkes mbd4 is thus the first bicoordinate copper-binding protein to be characterized structurally. Sequence comparisons with other heavy-metal-binding domains reveal a conserved hydrophobic core and metal-binding motif.


Subject(s)
Adenosine Triphosphatases/ultrastructure , Carrier Proteins/ultrastructure , Cation Transport Proteins , Copper , Recombinant Fusion Proteins , Adenosine Triphosphatases/chemistry , Amino Acid Sequence , Apoproteins/chemistry , Apoproteins/ultrastructure , Binding Sites , Carrier Proteins/chemistry , Copper-Transporting ATPases , Cysteine/chemistry , Humans , Membrane Proteins/ultrastructure , Metals, Heavy , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular , Protein Structure, Secondary , Protein Structure, Tertiary , Recombinant Proteins , Sequence Alignment , Sequence Homology, Amino Acid , Solutions , Structure-Activity Relationship
8.
Nature ; 396(6712): 699-703, 1998 Dec 17.
Article in English | MEDLINE | ID: mdl-9872321

ABSTRACT

Fas ligand (FasL) is produced by activated T cells and natural killer cells and it induces apoptosis (programmed cell death) in target cells through the death receptor Fas/Apol/CD95. One important role of FasL and Fas is to mediate immune-cytotoxic killing of cells that are potentially harmful to the organism, such as virus-infected or tumour cells. Here we report the discovery of a soluble decoy receptor, termed decoy receptor 3 (DcR3), that binds to FasL and inhibits FasL-induced apoptosis. The DcR3 gene was amplified in about half of 35 primary lung and colon tumours studied, and DcR3 messenger RNA was expressed in malignant tissue. Thus, certain tumours may escape FasL-dependent immune-cytotoxic attack by expressing a decoy receptor that blocks FasL.


Subject(s)
Colonic Neoplasms/genetics , Lung Neoplasms/genetics , Membrane Glycoproteins/metabolism , Receptors, Cell Surface/metabolism , Receptors, Tumor Necrosis Factor/metabolism , Adult , Amino Acid Sequence , Apoptosis , Colonic Neoplasms/immunology , Cytotoxicity, Immunologic , DNA, Complementary , Expressed Sequence Tags , Fas Ligand Protein , Gene Amplification , Humans , Jurkat Cells , Killer Cells, Natural/immunology , Ligands , Lung Neoplasms/immunology , Membrane Glycoproteins/antagonists & inhibitors , Molecular Sequence Data , Polymerase Chain Reaction , RNA, Messenger/metabolism , Receptors, Cell Surface/genetics , Receptors, Cell Surface/isolation & purification , Receptors, Tumor Necrosis Factor, Member 6b , Sequence Homology, Amino Acid , Tissue Distribution , Tumor Cells, Cultured , fas Receptor
9.
Science ; 277(5327): 818-21, 1997 Aug 08.
Article in English | MEDLINE | ID: mdl-9242611

ABSTRACT

TRAIL (also called Apo2L) belongs to the tumor necrosis factor family, activates rapid apoptosis in tumor cells, and binds to the death-signaling receptor DR4. Two additional TRAIL receptors were identified. The receptor designated death receptor 5 (DR5) contained a cytoplasmic death domain and induced apoptosis much like DR4. The receptor designated decoy receptor 1 (DcR1) displayed properties of a glycophospholipid-anchored cell surface protein. DcR1 acted as a decoy receptor that inhibited TRAIL signaling. Thus, a cell surface mechanism exists for the regulation of cellular responsiveness to pro-apoptotic stimuli.


Subject(s)
Apoptosis , Membrane Glycoproteins/metabolism , Receptors, Tumor Necrosis Factor/metabolism , Tumor Necrosis Factor-alpha/metabolism , Amino Acid Sequence , Apoptosis Regulatory Proteins , Cell Membrane/metabolism , Cells, Cultured , GPI-Linked Proteins , Glycosylphosphatidylinositols/metabolism , HeLa Cells , Humans , Ligands , Molecular Sequence Data , NF-kappa B/metabolism , Receptors, TNF-Related Apoptosis-Inducing Ligand , Receptors, Tumor Necrosis Factor/chemistry , Receptors, Tumor Necrosis Factor/genetics , Receptors, Tumor Necrosis Factor, Member 10c , Signal Transduction , TNF-Related Apoptosis-Inducing Ligand , Transfection , Tumor Cells, Cultured , Tumor Necrosis Factor Decoy Receptors
10.
J Biol Chem ; 272(17): 11128-32, 1997 Apr 25.
Article in English | MEDLINE | ID: mdl-9111009

ABSTRACT

It has been previously demonstrated that growth hormone (GH)-stimulated tyrosine phosphorylation of Jak2 and Stat5a and Stat5b occurs in FDP-C1 cells expressing either the entire GH receptor or truncations of the cytoplasmic domain expressing only the membrane-proximal 80 amino acids. However, other receptor domains that might modulate rates of GH activation and inactivation of this cascade have not been examined. Here we have defined a region in the human GH receptor between amino acids 520 and 540 in the cytoplasmic domain that is required for attenuation of GH-activated Jak/Stat signaling. Immunoprecipitations with antibodies to Jak2 indicate that the protein tyrosine phosphatase SHP-1 is associated with this kinase in cells exposed to GH. To address the possibility that SHP-1 could function as a negative regulator of GH signaling, liver extracts from motheaten mice deficient in SHP-1 or unaffected littermates were analyzed for activation of Stats and Jak2. Extracts from motheaten mice displayed prolonged activation of the Stat proteins as measured by their ability to interact with DNA and prolonged tyrosine phosphorylation of Jak2. These results delineate a novel domain in the GH receptor that regulates the inactivation of the Jak/Stat pathway and appears to be modulated by SHP-1.


Subject(s)
DNA-Binding Proteins/metabolism , Growth Hormone/pharmacology , Milk Proteins , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins , Receptors, Somatotropin/metabolism , Signal Transduction , Trans-Activators/metabolism , Animals , Humans , Intracellular Signaling Peptides and Proteins , Janus Kinase 2 , Liver/metabolism , Mice , Mice, Mutant Strains , Phosphorylation , Protein Binding , Protein Tyrosine Phosphatase, Non-Receptor Type 11 , Protein Tyrosine Phosphatase, Non-Receptor Type 6 , Protein Tyrosine Phosphatases/genetics , Protein Tyrosine Phosphatases/metabolism , Receptors, Somatotropin/genetics , STAT5 Transcription Factor , Sequence Deletion , Subcellular Fractions/metabolism , Tumor Suppressor Proteins
11.
Cytokine ; 8(12): 920-6, 1996 Dec.
Article in English | MEDLINE | ID: mdl-9050750

ABSTRACT

Cardiotrophin-1 (CT-1) is a recently discovered cytokine that was isolated based on its ability to induce cardiac myocyte hypertrophy in vitro. In this study, the effects of chronic administration of CT-1 to mice (0.5 or 2 microg by intraperitoneal injection, twice a day for 14 days) were determined. A dose-dependent increase in both the heart weight and ventricular weight to body ratios was observed in the treated groups. The body weights of the animals were unaffected. These results indicate that CT-1 can induce cardiac hypertrophy in vivo. CT-1 was not specific for the heart, however. It stimulated the growth of the liver, kidney, and spleen, and caused atrophy of the thymus. CT-1 administration also increased the platelet counts by 70%, with no change in mean platelet volume. Red blood cell counts were increased in the treated animals, and there was a concomitant increase in haemoglobin concentration. Thus, CT-1 has a broad spectrum of biological activities in vivo. This observation is consistent with previous in-vitro findings showing that the mRNA for CT-1 is expressed in several tissues, and that CT-1 can function through binding to the leukaemia inhibitory factor (LIF) receptor and signalling through the gp130 pathway.


Subject(s)
Cytokines/pharmacology , Heart/drug effects , Animals , Blood Proteins/drug effects , Female , Hematologic Tests , Kidney/drug effects , Liver/drug effects , Mice , Spleen/drug effects , Thymus Gland/drug effects
12.
Cytokine Growth Factor Rev ; 7(1): 81-91, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8864356

ABSTRACT

In a search for novel factors that induce cardiac myocyte hypertrophy, cardiotrophin-1 (CT-1) was identified by coupling expression cloning with an embryonic stem cell-based model of cardiogenesis. CT-1 is a new member of the IL-6 family of cytokines that induce their biological effects through the shared signaling subunit, gp 130. The expression pattern of CT-1 and its range of activities in the hematopoietic, neuronal, and developmental assays suggest that CT-1 may play an important role in other organ systems, in addition to its actions in cardiac development and hypertrophy.


Subject(s)
Antigens, CD/physiology , Cytokines/physiology , Growth Inhibitors , Interleukin-6 , Lymphokines/physiology , Membrane Glycoproteins/physiology , Receptors, Cytokine/physiology , Signal Transduction/physiology , Amino Acid Sequence , Animals , Cardiomegaly/pathology , Cardiomegaly/physiopathology , Cells, Cultured , Cytokine Receptor gp130 , Cytokines/genetics , Humans , Leukemia Inhibitory Factor , Leukemia Inhibitory Factor Receptor alpha Subunit , Molecular Sequence Data , Receptors, OSM-LIF
13.
J Biol Chem ; 271(16): 9535-45, 1996 Apr 19.
Article in English | MEDLINE | ID: mdl-8621626

ABSTRACT

Cardiotrophin-1 (CT-1) was recently isolated by expression cloning based on its ability to induce an increase in cell size in neonatal rat ventricular cardiomyocytes. Sequence similarity data suggested that CT-1 is a novel member of a family of structurally related cytokines sharing the receptor component gp130. The present study documents that gp130 is required for CT-1 signaling in cardiomyocytes, by demonstrating that a monoclonal anti-gp130 antibody completely inhibits c-fos induction by CT-1. Similarly, a leukemia inhibitory factor receptor subunit beta (LIFRbeta) antagonist effectively blocks the CT-1 induction of c-fos, indicating a requirement for LIFRbeta in the hypertrophic response, as well. Upon stimulation with CT-1, both gpl30 and the LIFRbeta are tyrosine-phosphorylated, providing further evidence that CT-1 signals through the gp130/LIFRbeta heterodimer in cardiomyocytes. CT-1 induces a hypertrophic response in cardiomyocytes that is distinct from the phenotype seen after alpha-adrenergic stimulation, both with regard to cell morphology and gene expression pattern. Stimulation with CT-1 results in an increase in cardiac cell size that is characterized by an increase in cell length but no significant change in cell width. Confocal laser microscopy of CT-1 stimulated cells reveals the assembly of sarcomeric units in series rather than in parallel, as seen after alpha-adrenergic stimulation. CT-1 induces a distinct pattern of immediate early genes, and up-regulates the atrial natriuretic factor (ANF) gene, but does not affect skeletal alpha-actin or myosin light chain-2v expression. As evidenced by nuclear run-on transcription assays, both CT-1 and alpha-adrenergic stimulation lead to an increase in ANF gene transcription. Transient transfection analyses document that, in contrast to alpha-adrenergic stimulation, the CT-1 responsive cis-regulatory elements are located outside of the proximal 3 kilobase pairs of the ANF 5'-flanking region. These studies indicate that CT-1 can activate a distinct form of myocardial cell hypertrophy, characterized by the promotion of sarcomere assembly in series, via gpl30/LIFRbeta-dependent signaling pathways.


Subject(s)
Cytokines/pharmacology , Gene Expression/drug effects , Growth Inhibitors/pharmacology , Heart/drug effects , Interleukin-6 , Lymphokines/pharmacology , Myocardium/cytology , Receptors, Cytokine/physiology , Sarcomeres/ultrastructure , Actins/biosynthesis , Animals , Atrial Natriuretic Factor/biosynthesis , Cells, Cultured , Ciliary Neurotrophic Factor , Cytokines/biosynthesis , Genes, fos , Humans , Leukemia Inhibitory Factor , Leukemia Inhibitory Factor Receptor alpha Subunit , Mice , Myocardium/metabolism , Myocardium/pathology , Nerve Growth Factors/pharmacology , Nerve Tissue Proteins/pharmacology , Proto-Oncogene Proteins c-fos/biosynthesis , Receptors, OSM-LIF , Recombinant Fusion Proteins/biosynthesis , Sarcomeres/drug effects , Sarcomeres/physiology , Signal Transduction , Transfection
14.
J Biol Chem ; 271(10): 5947-52, 1996 Mar 08.
Article in English | MEDLINE | ID: mdl-8621469

ABSTRACT

The binding of growth hormone leads to dimerization of its receptor, accompanied by phosphorylation and activation of intracellular tyrosine kinases (JAKs) and the latent cytoplasmic transcriptions factors STAT1, STAT3, and STAT5. Both JAK1 and JAK2 are phosphorylated in response to growth hormone in mouse 3T3 F442A and human HT1080 cells. The roles of JAKs in growth hormone signal transduction were examined by using mutant HT1080 cells missing either JAK1 or JAK2. JAK2 is absolutely required for growth hormone-dependent phosphorylation of the receptor, STAT1 and STAT3, JAK1, and the SH2-containing adaptor molecule Shc. In contrast, JAK1 is not required for any of the above functions. These data indicate that JAK2 is both necessary and sufficient for the growth hormone-dependent phosphorylation events required to couple the receptor both to STAT-dependent signaling pathways and to pathways involving Shc. Furthermore, STAT5 is activated by growth hormone in 3T3 F442A cells, but not in HT1080 cells, revealing that the set of STATs activated by growth hormone can vary, possibly contributing to the specificity of the growth hormone response in different cell types.


Subject(s)
Growth Hormone/pharmacology , Milk Proteins , Protein-Tyrosine Kinases/metabolism , Proto-Oncogene Proteins , Signal Transduction , Transcription Factors/metabolism , 3T3 Cells , Animals , Cell Line , DNA-Binding Proteins/metabolism , Humans , Interferon-alpha/pharmacology , Interferon-gamma/pharmacology , Janus Kinase 1 , Janus Kinase 2 , Kinetics , Mice , Phosphoproteins/isolation & purification , Phosphoproteins/metabolism , Phosphorylation , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , STAT1 Transcription Factor , STAT3 Transcription Factor , STAT5 Transcription Factor , Trans-Activators/metabolism , Transfection
15.
Cytokine ; 8(3): 183-9, 1996 Mar.
Article in English | MEDLINE | ID: mdl-8833032

ABSTRACT

Cardiotrophin-1 (CT-1) is a new member of the interleukin-6 cytokine family that was identified from a mouse embryoid body cDNA library by expression cloning. Mouse CT-1 induces features of hypertrophy in neonatal rat cardiac myocytes and binds to and activates the leukaemia inhibitory factor/gp130 receptor complex. In this work we report the isolation and characterization of cDNA and genomic clones encoding human CT-1. These clones encode a 201 amino acid protein that is 80% identical to the mouse protein. Human CT-1 produced by transfection of the cDNA clones into mammalian cells induces the hypertrophy of neonatal rat cardiac myocytes. Human and mouse CT-1 bind to the leukaemia inhibitory factor receptor on both human and mouse cell lines indicating a lack of species specificity. No binding to the human oncostatin M specific receptor was detected. A 1.7 kb CT-1 mRNA is expressed in adult human heart, skeletal muscle, ovary, colon, prostate and testis and in fetal kidney and lung. The coding region of CT-1 is contained on three exons and is located on human chromosome 16p11.1-16p11.2.


Subject(s)
Chromosomes, Human, Pair 16 , Cytokines/chemistry , Cytokines/genetics , Amino Acid Sequence , Animals , Base Sequence , Cell Line , Chromosome Mapping , Cloning, Molecular , Consensus Sequence , Cytokines/metabolism , DNA, Complementary , Exons , Female , Gene Library , HeLa Cells , Humans , Hybrid Cells , In Situ Hybridization, Fluorescence , Male , Mice , Molecular Sequence Data , Organ Specificity , RNA, Messenger/biosynthesis , Rats , Receptors, Cytokine/metabolism , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Transfection
16.
Proc Natl Acad Sci U S A ; 93(5): 1988-92, 1996 Mar 05.
Article in English | MEDLINE | ID: mdl-8700872

ABSTRACT

The tyrosine kinases Flt4, Flt1, and Flk1 (or KDR) constitute a family of endothelial cell-specific receptors with seven immunoglobulin-like domains and a split kinase domain. Flt1 and Flk1 have been shown to play key roles in vascular development; these two receptors bind and are activated by vascular endothelial growth factor (VEGF). No ligand has been identified for Flt4, whose expression becomes restricted during development to the lymphatic endothelium. We have identified cDNA clones from a human glioma cell line that encode a secreted protein with 32% amino acid identity to VEGF. This protein, designated VEGF-related protein (VRP), specifically binds to the extracellular domain of Flt4, stimulates the tyrosine phosphorylation of Flt4 expressed in mammalian cells, and promotes the mitogenesis of human lung endothelial cells. VRP fails to bind appreciably to the extracellular domain of Flt1 or Flk1. The protein contains a C-terminal, cysteine-rich region of about 180 amino acids that is not found in VEGF. A 2.4-kb VRP mRNA is found in several human tissues including adult heart, placenta, ovary, and small intestine and in fetal lung and kidney.


Subject(s)
Carrier Proteins/metabolism , Endothelial Growth Factors/chemistry , Lymphokines/chemistry , Receptor Protein-Tyrosine Kinases/metabolism , Receptors, Cell Surface/metabolism , Amino Acid Sequence , Base Sequence , Cloning, Molecular , DNA, Complementary/genetics , Enzyme Activation , Gene Expression , Immunoglobulin G/metabolism , Molecular Sequence Data , Phosphotyrosine/metabolism , Protein Binding , Sequence Alignment , Sequence Homology, Amino Acid , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factor B , Vascular Endothelial Growth Factor Receptor-3 , Vascular Endothelial Growth Factors
17.
Development ; 122(2): 419-28, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8625793

ABSTRACT

We have recently isolated a novel cytokine, cardiotrophin-1 (CT-1), from an in vitro embryonic stem cell system of cardiogenesis that can activate embryonic markers in neonatal rat cardiac myocytes. CT-1 is a new member of the interleukin 6 (IL-6)/leukemia inhibitory factor (LIF) cytokines, which activate downstream signals via gp130-dependent pathways. To define the developmental pattern of expression of CT-1 during murine embryogenesis, we have developed antibodies directed against a CT-1 fusion protein. As assessed by immunolocalization, CT-1 is predominantly expressed in the early mouse embryonic heart tube (E8.5-10.5). In the heart, CT-1 is primarily expressed in myocardial cells, and not in endocardial cushion or outflow tract tissues. After E12.5, CT-1 expression is found in other tissues, including skeletal, liver and dorsal root ganglia. Given the effects of a related family member (ciliary neurotrophic factor, CNTF) on neuronal cell survival, we studied the ability of CT-1 to promote cardiac myocyte survival and proliferation in vitro. Both CT-1 and LIF, which share the same receptors, dramatically promote neonatal cardiac myocyte survival, while IL-6 and CNTF are without effect. A cell proliferation assay documents that CT-1 provokes an approximate 2-fold increase in embryonic cardiac myocyte proliferation. Thus, CT-1 may play an autocrine role during cardiac chamber growth and morphogenesis by promoting the survival and proliferation of immature myocytes, most likely via gp130-dependent signaling pathways.


Subject(s)
Cytokines/biosynthesis , Embryonic and Fetal Development , Gene Expression Regulation , Heart/embryology , Myocardium/metabolism , Animals , Animals, Newborn , Base Sequence , Cell Division , Cell Survival , Cells, Cultured , Cytokines/analysis , DNA Primers , Ganglia, Spinal/embryology , Ganglia, Spinal/metabolism , Gestational Age , Immunohistochemistry , Liver/embryology , Liver/metabolism , Mice , Molecular Sequence Data , Muscle, Skeletal/embryology , Muscle, Skeletal/metabolism , Myocardium/cytology , Organ Specificity , Polymerase Chain Reaction , Rats , Stem Cells/physiology
18.
Science ; 269(5230): 1591, 1995 Sep 15.
Article in English | MEDLINE | ID: mdl-17789451
19.
J Immunol ; 155(4): 2158-64, 1995 Aug 15.
Article in English | MEDLINE | ID: mdl-7636264

ABSTRACT

In humans and rabbits two similar IL-8R mediate the chemotaxis and activation of neutrophils induced by alpha chemokines. We present data to suggest that there is only one such IL-8R gene in mice. We then use mice with a targeted deletion of this gene to characterize alpha chemokine ligands that signal via the mouse IL-8R. These experiments show that mouse macrophage inflammatory protein 2 binds the receptor with high affinity (Kd = approximately 1.5 nM) and potently activates both an intracellular Ca2+ flux and a chemotactic response, events absent in neutrophils from receptor-deleted mice. Mouse KC is approximately 10-fold less potent. These results show that macrophage inflammatory protein 2 and KC potently activate mouse neutrophils via a unique IL-8R, and these proteins may function as the major proinflammatory alpha chemokines in mice.


Subject(s)
Cytokines/pharmacology , Interleukin-8/pharmacology , Monokines/pharmacology , Receptors, Interleukin/physiology , Animals , Calcium/metabolism , Chemokine CXCL1 , Chemokine CXCL2 , Chemokines , Chemokines, CXC , Cytokines/metabolism , Humans , Interleukin-8/metabolism , Mice , Mice, Inbred C57BL , Monokines/metabolism , Neutrophils/metabolism , Receptors, Interleukin/genetics , Receptors, Interleukin-8A
20.
Gene ; 158(2): 305-6, 1995 Jun 09.
Article in English | MEDLINE | ID: mdl-7607560

ABSTRACT

The amino acid (aa) sequence of rat V-1, a developmentally regulated brain protein, was used to isolate clones encoding mouse V-1, a protein of 118 aa, from an embryoid body cDNA library. The aa sequences of rat and mouse V-1 are identical. V-1 shares several properties (including a 23 of 24 aa match of a tryptic peptide) with myotrophin, a protein that induces cardiac myocyte hypertrophy. Attempts to show that V-1 produced in Escherichia coli could induce the cardiac myocyte hypertrophy ascribed to myotrophin were unsuccessful.


Subject(s)
Cardiomegaly/chemically induced , Intercellular Signaling Peptides and Proteins , Nerve Tissue Proteins/genetics , Amino Acid Sequence , Animals , Base Sequence , DNA, Complementary/genetics , Escherichia coli/genetics , Gene Library , Growth Substances/pharmacology , Mice , Molecular Sequence Data , Nerve Tissue Proteins/biosynthesis , Nerve Tissue Proteins/pharmacology , Recombinant Fusion Proteins/biosynthesis , Sequence Homology, Amino Acid
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