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Wang RX, Yu CR, Mahdi RM, Egwuagu CE. Novel IL27p28/IL12p40 cytokine suppressed experimental autoimmune uveitis by inhibiting autoreactive Th1/Th17 cells and promoting expansion of regulatory T cells. J Biol Chem 2012; 287:36012-21. [PMID: 22936807 PMCID: PMC3476269 DOI: 10.1074/jbc.m112.390625] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/27/2012] [Indexed: 12/24/2022] Open
Abstract
IL-12 family cytokines are important in host immunity. Whereas some members (IL-12, IL-23) play crucial roles in pathogenesis of organ-specific autoimmune diseases by inducing the differentiation of Th1 and Th17 lymphocytes, others (IL-27 and IL-35) suppress inflammatory responses and limit tissue injury induced by these T cell subsets. In this study, we have genetically engineered a novel IL27p28/IL12p40 heterodimeric cytokine (p28/p40) that antagonizes signaling downstream of the gp130 receptor. We investigated whether p28/p40 can be used to ameliorate uveitis, a CNS inflammatory disease. Experimental autoimmune uveitis (EAU) is the mouse model of human uveitis and is mediated by Th1 and Th17 cells. We show here that p28/p40 suppressed EAU by inhibiting the differentiation and inflammatory responses of Th1 and Th17 cells while promoting expansion of IL-10(+)- and Foxp3(+)-expressing regulatory T cells. Lymph node cells from mice treated with p28/p40 blocked adoptive transfer of EAU to naïve syngeneic mice by immunopathogenic T cells and suppressive effects of p28/p40 derived in part from antagonizing STAT1 and STAT3 pathways induced by IL-27 and IL-6. Interestingly, IL27p28 also suppressed EAU, but to a lesser extent than p28/p40. The inhibition of uveitogenic lymphocyte proliferation and suppression of EAU by p28/p40 and IL27p28 establish efficacy of single chain and heterodimeric IL-12 family cytokines in treatment of a CNS autoimmune disease. Creation of the biologically active p28/p40 heterodimeric cytokine represents an important proof-of-concept experiment, suggesting that cytokines comprising unique IL-12 α- and β-subunit pairing may exist in nature and may constitute a new class of therapeutic cytokines.
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Affiliation(s)
- Ren-Xi Wang
- From the Molecular Immunology Section, Laboratory of Immunology, NEI, National Institutes of Health, Bethesda, Maryland 20892-1857
| | - Cheng-Rong Yu
- From the Molecular Immunology Section, Laboratory of Immunology, NEI, National Institutes of Health, Bethesda, Maryland 20892-1857
| | - Rashid M. Mahdi
- From the Molecular Immunology Section, Laboratory of Immunology, NEI, National Institutes of Health, Bethesda, Maryland 20892-1857
| | - Charles E. Egwuagu
- From the Molecular Immunology Section, Laboratory of Immunology, NEI, National Institutes of Health, Bethesda, Maryland 20892-1857
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2
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Shah S, Henriksen MA. A novel disrupter of telomere silencing 1-like (DOT1L) interaction is required for signal transducer and activator of transcription 1 (STAT1)-activated gene expression. J Biol Chem 2011; 286:41195-41204. [PMID: 22002246 PMCID: PMC3308833 DOI: 10.1074/jbc.m111.284190] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 09/21/2011] [Indexed: 01/14/2023] Open
Abstract
JAK-STAT-activated gene expression is both rapid and transient and requires dynamic post-translational modification of the chromatin template. Previously, we showed that following IFN-γ treatment, trimethylation of histone H3 at lysine 79 (H3K79me3) is rapidly and highly induced in the 5'-end of the STAT1-dependent gene interferon regulatory factor 1 (IRF1), but the role of this histone modification was unexplored. Here we report that DOT1L, the non-SET domain containing methyltransferase that modifies Lys-79, is localized across IRF1 in the uninduced state and is not further recruited by IFN-γ induction. RNAi-mediated depletion of DOT1L prevents the induction of H3K79me3 and lowers the transcription of IRF1 2-fold, as expected. Surprisingly, STAT1 binding to its DNA recognition element near the IRF1 promoter is diminished 2-fold in the DOT1L-depleted cell line. In vivo and in vitro protein interaction assays reveal a DOT1L-STAT1 interaction. Domain mapping identifies the middle region of DOT1L (amino acids 580-1183) as the STAT1 interaction domain. Overexpression of the DOT1L STAT1 interaction domain represses IRF1 transcription (2-fold) and interferes with STAT1 DNA binding at IRF1 and endogenous DOT1L histone methyltransferase activity. Collectively, our findings reveal a novel STAT1-DOT1L interaction that is required for the regulation JAK-STAT-inducible gene expression.
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Affiliation(s)
- Shaili Shah
- Department of Biology, The University of Virginia, Charlottesville, Virginia 22903
| | - Melissa A Henriksen
- Department of Biology, The University of Virginia, Charlottesville, Virginia 22903.
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3
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Barthson J, Germano CM, Moore F, Maida A, Drucker DJ, Marchetti P, Gysemans C, Mathieu C, Nuñez G, Jurisicova A, Eizirik DL, Gurzov EN. Cytokines tumor necrosis factor-α and interferon-γ induce pancreatic β-cell apoptosis through STAT1-mediated Bim protein activation. J Biol Chem 2011; 286:39632-43. [PMID: 21937453 PMCID: PMC3234786 DOI: 10.1074/jbc.m111.253591] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 09/13/2011] [Indexed: 11/06/2022] Open
Abstract
Type 1 diabetes is characterized by local inflammation (insulitis) in the pancreatic islets causing β-cell loss. The mitochondrial pathway of apoptosis is regulated by the balance and interaction between Bcl-2 members. Here we clarify the molecular mechanism of β-cell death triggered by the pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ. The combination of TNF-α + IFN-γ induced DP5, p53 up-regulated modulator of apoptosis (PUMA), and Bim expression in human islets and rodent β-cells. DP5 and PUMA inactivation by RNA interference partially protected against TNF-α + IFN-γ-induced β-cell apoptosis. DP5 knock-out mice had increased β-cell area, and isolated islets from these mice were resistant to cytokine exposure. Bim expression was transcriptionally regulated by STAT1, and its activation triggered cleavage of caspases. Silencing of Bim protected rodent and human β-cells to a large extent against TNF-α + IFN-γ, indicating a major role of this BH3-only activator protein in the mechanism of apoptosis. Our data support a highly regulated and context-dependent modulation of specific Bcl-2 members controlling the mitochondrial pathway of β-cell apoptosis during insulitis.
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Affiliation(s)
- Jenny Barthson
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | - Carla M. Germano
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | - Fabrice Moore
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | | | | | - Piero Marchetti
- the Department of Endocrinology and Metabolism, Metabolic Unit, University of Pisa, 56126 Pisa, Italy
| | - Conny Gysemans
- the Department of Experimental Medicine Endocrinology, Faculty of Medicine, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium, and
| | - Chantal Mathieu
- the Department of Experimental Medicine Endocrinology, Faculty of Medicine, Katholieke Universiteit Leuven (KUL), 3000 Leuven, Belgium, and
| | - Gabriel Nuñez
- the Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Andrea Jurisicova
- Obstetrics and Gynecology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, Ontario M5G 1X5, Canada
| | - Decio L. Eizirik
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
| | - Esteban N. Gurzov
- From the Laboratory of Experimental Medicine, Université Libre de Bruxelles (ULB), Route de Lennik, 808, 1070 Brussels, Belgium
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4
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Testoni B, Völlenkle C, Guerrieri F, Gerbal-Chaloin S, Blandino G, Levrero M. Chromatin dynamics of gene activation and repression in response to interferon alpha (IFN(alpha)) reveal new roles for phosphorylated and unphosphorylated forms of the transcription factor STAT2. J Biol Chem 2011; 286:20217-27. [PMID: 21498520 PMCID: PMC3121502 DOI: 10.1074/jbc.m111.231068] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 04/06/2011] [Indexed: 01/01/2023] Open
Abstract
Signal transducer and activator of transcription 2 (STAT2), the critical component of type I interferons signaling, is a prototype latent cytoplasmic signal-dependent transcription factor. Activated tyrosine-phosphorylated STAT2 associates with STAT1 and IRF9 to bind the ISRE elements in the promoters of a subset of IFN-inducible genes (ISGs). In addition to activate hundreds of ISGs, IFNα also represses numerous target genes but the mechanistic basis for this dual effect and transcriptional repression is largely unknown. We investigated by ChIP-chip the binding dynamics of STAT2 and "active" phospho(P)-STAT2 on 113 putative IFNα direct target promoters before and after IFNα induction in Huh7 cells and primary human hepatocytes (PHH). STAT2 is already bound to 62% of our target promoters, including most "classical" ISGs, before IFNα treatment. 31% of STAT2 basally bound promoters also show P-STAT2 positivity. By correlating in vivo promoter occupancy with gene expression and changes in histone methylation marks we found that: 1) STAT2 plays a role in regulating ISGs expression, independently from its phosphorylation; 2) P-STAT2 is involved in ISGs repression; 3) "activated" ISGs are marked by H3K4me1 and H3K4me3 before IFNα; 4) "repressed" genes are marked by H3K27me3 and histone methylation plays a dominant role in driving IFNα-mediated ISGs repression.
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Affiliation(s)
- Barbara Testoni
- From the Laboratory of Gene Expression, Fondazione A. Cesalpino, 00161 Rome, Italy
- the Rome Oncogenomic Center, Regina Elena Cancer Institute, 00144 Rome, Italy
| | - Christine Völlenkle
- From the Laboratory of Gene Expression, Fondazione A. Cesalpino, 00161 Rome, Italy
- the Rome Oncogenomic Center, Regina Elena Cancer Institute, 00144 Rome, Italy
| | - Francesca Guerrieri
- From the Laboratory of Gene Expression, Fondazione A. Cesalpino, 00161 Rome, Italy
- the LEA INSERM U785 and Sapienza University, 00161 Rome, Italy
| | | | - Giovanni Blandino
- the Rome Oncogenomic Center, Regina Elena Cancer Institute, 00144 Rome, Italy
- the Regina Elena Cancer Institute, Translational Oncogenomic Unit, 00144 Rome, Italy, and
| | - Massimo Levrero
- From the Laboratory of Gene Expression, Fondazione A. Cesalpino, 00161 Rome, Italy
- the Rome Oncogenomic Center, Regina Elena Cancer Institute, 00144 Rome, Italy
- the LEA INSERM U785 and Sapienza University, 00161 Rome, Italy
- the DMISM, Sapienza University, 00161 Rome, Italy
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Heldsinger A, Grabauskas G, Song I, Owyang C. Synergistic interaction between leptin and cholecystokinin in the rat nodose ganglia is mediated by PI3K and STAT3 signaling pathways: implications for leptin as a regulator of short term satiety. J Biol Chem 2011; 286:11707-15. [PMID: 21270124 PMCID: PMC3064222 DOI: 10.1074/jbc.m110.198945] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 01/25/2011] [Indexed: 11/06/2022] Open
Abstract
Research has shown that the synergistic interaction between vagal cholecystokinin-A receptors (CCKARs) and leptin receptors (LRbs) mediates short term satiety. We hypothesize that this synergistic interaction is mediated by cross-talk between signaling cascades used by CCKARs and LRbs, which, in turn, activates closure of K(+) channels, leading to membrane depolarization and neuronal firing. Whole cell patch clamp recordings were performed on isolated rat nodose ganglia neurons. Western immunoblots elucidated the intracellular signaling pathways that modulate leptin/CCK synergism. In addition, STAT3, PI3K, Src, and MAPK genes were silenced by lentiviral infection and transient Lipofectamine transfection of cultured rat nodose ganglia to determine the effect of these molecules on leptin/CCK synergism. Patch clamp studies showed that a combination of leptin and CCK-8 caused a significant increase in membrane input resistance compared with leptin or CCK-8 alone. Silencing the STAT3 gene abolished the synergistic action of leptin/CCK-8 on neuronal firing. Leptin/CCK-8 synergistically stimulated a 7.7-fold increase in phosphorylated STAT3 (pSTAT3), which was inhibited by AG490, C3 transferase, PP2, LY294002, and wortmannin, but not PD98059. Silencing the Src and PI3K genes resulted in a loss of leptin/CCK-stimulated pSTAT3. We conclude that the synergistic interaction between vagal CCKARs and LRbs is mediated by the phosphorylation of STAT3, which, in turn, activates closure of K(+) channels, leading to membrane depolarization and neuronal firing. This involves the interaction between CCK/Src/PI3K cascades and leptin/JAK2/PI3K/STAT3 signaling pathways. Malfunctioning of these signaling molecules may result in eating disorders.
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Affiliation(s)
- Andrea Heldsinger
- From the Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Gintautas Grabauskas
- From the Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Il Song
- From the Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
| | - Chung Owyang
- From the Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
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Wang H, Holloway MP, Ma L, Cooper ZA, Riolo M, Samkari A, Elenitoba-Johnson KSJ, Chin YE, Altura RA. Acetylation directs survivin nuclear localization to repress STAT3 oncogenic activity. J Biol Chem 2010; 285:36129-37. [PMID: 20826784 PMCID: PMC2975235 DOI: 10.1074/jbc.m110.152777] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Revised: 09/07/2010] [Indexed: 02/05/2023] Open
Abstract
The multiple functions of the oncofetal protein survivin are dependent on its selective expression patterns within immunochemically distinct subcellular pools. The mechanism by which survivin localizes to these compartments, however, is only partly understood. Here we show that nuclear accumulation of survivin is promoted by CREB-binding protein (CBP)-dependent acetylation on lysine 129 (129K, Lys-129). We demonstrate a mechanism by which survivin acetylation at this position results in its homodimerization, while deacetylation promotes the formation of survivin monomers that heterodimerize with CRM1 and facilitate its nuclear export. Using proteomic analysis, we identified the oncogenic transcription factor STAT3 as a binding partner of nuclear survivin. We show that acetylated survivin binds to the N-terminal transcriptional activation domain of the STAT3 dimer and represses STAT3 transactivation of target gene promoters. Using multiplex PCR and DNA sequencing, we identified a single-nucleotide polymorphism (A → G) at Lys-129 that exists as a homozygous mutation in a neuroblastoma cell line and corresponds with a defect in survivin nuclear localization. Our results demonstrate that the dynamic equilibrium between survivin acetylation and deacetylation at amino acid 129 determines its interaction with CRM1, its subsequent subcellular localization, and its ability to inhibit STAT3 transactivation, providing a potential route for therapeutic intervention in STAT3-dependent tumors.
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Affiliation(s)
| | | | - Li Ma
- Surgery, Brown University and Rhode Island Hospital, Providence, Rhode Island 02903 and
| | | | | | | | | | - Y. Eugene Chin
- Surgery, Brown University and Rhode Island Hospital, Providence, Rhode Island 02903 and
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7
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Li D, Jackson RA, Yusoff P, Guy GR. Direct association of Sprouty-related protein with an EVH1 domain (SPRED) 1 or SPRED2 with DYRK1A modifies substrate/kinase interactions. J Biol Chem 2010; 285:35374-85. [PMID: 20736167 PMCID: PMC2975161 DOI: 10.1074/jbc.m110.148445] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/23/2010] [Indexed: 12/30/2022] Open
Abstract
The mammalian SPRED (Sprouty-related protein with an EVH1 domain) proteins include a family of three members, SPRED1-3. Currently, little is known about their biochemistry. The best described, SPRED1, has been shown to inhibit the Ras/ERK pathway downstream of Ras. All three SPREDs have a cysteine-rich domain (CRD) that has high homology to the CRD of the Sprouty family of proteins, several of which are also Ras/ERK inhibitors. In the belief that binding partners would clarify SPRED function, we assayed for their associated proteins. Here, we describe the direct and endogenous interaction of SPRED1 and SPRED2 with the novel kinase, DYRK1A. DYRK1A has become the subject of recent research focus as it plays a central role in Caenorhabditis elegans oocyte maturation and egg activation, and there is strong evidence that it could be involved in Down syndrome in humans. Both SPRED1 and SPRED2 inhibit the ability of DYRK1A to phosphorylate its substrates, Tau and STAT3. This inhibition occurs via an interaction of the CRD of the SPREDs with the kinase domain of DYRK1A. DYRK1A substrates must bind to the kinase to enable phosphorylation, and SPRED proteins compete for the same binding site to modify this process. Our accumulated evidence indicates that the SPRED proteins are likely physiological modifiers of DYRK1A.
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Affiliation(s)
- Dan Li
- From the Institute of Molecular and Cell Biology, Signal Transduction Laboratory, 61 Biopolis Drive, Proteos 138673, Singapore
| | - Rebecca A. Jackson
- From the Institute of Molecular and Cell Biology, Signal Transduction Laboratory, 61 Biopolis Drive, Proteos 138673, Singapore
| | - Permeen Yusoff
- From the Institute of Molecular and Cell Biology, Signal Transduction Laboratory, 61 Biopolis Drive, Proteos 138673, Singapore
| | - Graeme R. Guy
- From the Institute of Molecular and Cell Biology, Signal Transduction Laboratory, 61 Biopolis Drive, Proteos 138673, Singapore
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Snyder M, Huang XY, Zhang JJ. Stat3 directly controls the expression of Tbx5, Nkx2.5, and GATA4 and is essential for cardiomyocyte differentiation of P19CL6 cells. J Biol Chem 2010; 285:23639-46. [PMID: 20522556 PMCID: PMC2911296 DOI: 10.1074/jbc.m110.101063] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 06/02/2010] [Indexed: 01/05/2023] Open
Abstract
The transcription factor Stat3 (signal transducer and activator of transcription 3) mediates many physiological processes, including embryogenesis, stem cell self-renewal, and postnatal survival. In response to gp130 receptor activation, Stat3 becomes phosphorylated by the receptor-associated Janus kinase, forms dimers, and enters the nucleus where it binds to Stat3 target genes and regulates their expression. In this report, we demonstrate that Stat3 binds directly to the promoters and regulates the expression of three genes that are essential for cardiac differentiation: Tbx5, Nkx2.5, and GATA4. We further demonstrate that Tbx5, Nkx2.5, and GATA4 expression is dependent on Stat3 in response to ligand treatment and during ligand-independent differentiation of P19CL6 cells into cardiomyocytes. Finally, we show that Stat3 is necessary for the differentiation of P19CL6 cells into beating cardiomyocytes. All together, these results demonstrate that Stat3 is required for the differentiation of cardiomyocytes through direct transcriptional regulation of Tbx5, Nkx2.5, and GATA4.
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Affiliation(s)
- Marylynn Snyder
- From the Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, New York 10065
| | - Xin-Yun Huang
- From the Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, New York 10065
| | - J. Jillian Zhang
- From the Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, New York 10065
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Litherland GJ, Elias MS, Hui W, Macdonald CD, Catterall JB, Barter MJ, Farren MJ, Jefferson M, Rowan AD. Protein kinase C isoforms zeta and iota mediate collagenase expression and cartilage destruction via STAT3- and ERK-dependent c-fos induction. J Biol Chem 2010; 285:22414-25. [PMID: 20463008 PMCID: PMC2903406 DOI: 10.1074/jbc.m110.120121] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 04/30/2010] [Indexed: 12/27/2022] Open
Abstract
The protein kinase C (PKC) signaling pathway is a major regulator of cellular functions and is implicated in pathologies involving extracellular matrix remodeling. Inflammatory joint disease is characterized by excessive extracellular matrix catabolism, and here we assess the role of PKC in the induction of the collagenases, matrix metalloproteinase (MMP)-1 and MMP-13, in human chondrocytes by the potent cytokine stimulus interleukin-1 (IL-1) in combination with oncostatin M (OSM). IL-1 + OSM-stimulated collagenolysis and gelatinase activity were ameliorated by pharmacological PKC inhibition in bovine cartilage, as was collagenase gene induction in human chondrocytes. Small interfering RNA-mediated silencing of PKC gene expression showed that both novel (nPKC delta, nPKC eta) and atypical (aPKC zeta, aPKC iota) isoforms were involved in collagenase induction by IL-1. However, MMP1 and MMP13 induction by IL-1 + OSM was inhibited only by aPKC silencing, suggesting that only atypical isoforms play a significant role in complex inflammatory milieus. Silencing of either aPKC led to diminished IL-1 + OSM-dependent extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription (STAT) 3 phosphorylation, and c-fos expression. STAT3 gene silencing or ERK pathway inhibition also resulted in loss of IL-1 + OSM-stimulated c-fos and collagenase expression. Silencing of c-fos and c-jun expression was sufficient to abrogate IL-1 + OSM-stimulated collagenase gene induction, and overexpression of both c-fos and c-jun was sufficient to drive transcription from the MMP1 promoter in the absence of a stimulus. Our data identify atypical PKC isozymes as STAT and ERK activators that mediate c-fos and collagenase expression during IL-1 + OSM synergy in human chondrocytes. aPKCs may constitute potential therapeutic targets for inflammatory joint diseases involving increased collagenase expression.
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Affiliation(s)
- Gary J. Litherland
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Martina S. Elias
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Wang Hui
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Christopher D. Macdonald
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Jonathon B. Catterall
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Matt J. Barter
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Matthew J. Farren
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Matthew Jefferson
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
| | - Andrew D. Rowan
- From the Cell Signalling, Injury and Repair Group, Institute of Cellular Medicine, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
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