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Wu YN, Zhang R, Song XC, Han XX, Zhang J, Li X. C6orf120 gene knockout in rats mitigates concanavalin A‑induced autoimmune hepatitis via regulating NKT cells. Cell Immunol 2022; 371:104467. [PMID: 34896761 DOI: 10.1016/j.cellimm.2021.104467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 04/12/2021] [Revised: 10/07/2021] [Accepted: 11/21/2021] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To elucidate the role of the functional unknown gene C6orf120 in the pathogenesis of AIH and its mechanism of action, using C6orf120 knockout rats. METHODS An autoimmune hepatitis model was established with 35 mg/kg intravenous injection of concanavalin A (Con A) in C6orf120-knockout (C6orf120-/-) and wild-type (WT) rats. Rats were sacrificed after administering Con A for 0, 12, and 24 h. The peripheral blood, liver, spleen, and mesenteric lymph nodes were collected for follow-up studies. RESULTS C6orf120 knockout significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and improved the histological damage in Con A-induced autoimmune liver injury.Loss of C6orf120 function significantly increased the frequency of CD3+ CD161+ NKT cells in the peripheral blood, liver, and spleen; downregulated the expression of CD314 (NKG2D) in the liver, spleen, and mesenteric lymph nodes; reduced the expression of inflammatory cytokines and chemokines; and suppressed the mRNA and protein expression of Fas and FasL in the liver. Additionally, C6orf120 knockout significantly downregulated the expression of p-JAK1, p-JAK2, p-STAT1, and p-STAT3 in liver tissue. CONCLUSION The protective effect of C6orf120 knockout against Con A-induced hepatitis may be due to the inhibition of NKT cell activation, restriction of cytokine and chemokine activities, inhibition of JAK-STAT and Fas/FasL signaling pathway activation, and reduction in liver inflammation and hepatocyte apoptosis.
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Affiliation(s)
- Yuan-Ni Wu
- Department of Center of Integrated Traditional Chinese and Western Medicine, Peking University Ditan Teaching Hospital, Beijing 100015, China
| | - Rui Zhang
- Department of Center of Integrated Traditional Chinese and Western Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Xin-Cheng Song
- Department of Center of Integrated Traditional Chinese and Western Medicine, Peking University Ditan Teaching Hospital, Beijing 100015, China
| | - Xiao-Xu Han
- Department of Center of Integrated Traditional Chinese and Western Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China
| | - Jian Zhang
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao 266011, China
| | - Xin Li
- Department of Center of Integrated Traditional Chinese and Western Medicine, Peking University Ditan Teaching Hospital, Beijing 100015, China; Department of Center of Integrated Traditional Chinese and Western Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing 100015, China.
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Nan Y, Wu C, Zhang YJ. Interferon Independent Non-Canonical STAT Activation and Virus Induced Inflammation. Viruses 2018; 10:v10040196. [PMID: 29662014 PMCID: PMC5923490 DOI: 10.3390/v10040196] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 04/07/2018] [Accepted: 04/11/2018] [Indexed: 02/06/2023] Open
Abstract
Interferons (IFNs) are a group of secreted proteins that play critical roles in antiviral immunity, antitumor activity, activation of cytotoxic T cells, and modulation of host immune responses. IFNs are cytokines, and bind receptors on cell surfaces to trigger signal transduction. The major signaling pathway activated by IFNs is the JAK/STAT (Janus kinase/signal transducer and activator of transcription) pathway, a complex pathway involved in both viral and host survival strategies. On the one hand, viruses have evolved strategies to escape from antiviral host defenses evoked by IFN-activated JAK/STAT signaling. On the other hand, viruses have also evolved to exploit the JAK/STAT pathway to evoke activation of certain STATs that somehow promote viral pathogenesis. In this review, recent progress in our understanding of the virus-induced IFN-independent STAT signaling and its potential roles in viral induced inflammation and pathogenesis are summarized in detail, and perspectives are provided.
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Affiliation(s)
- Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China.
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA.
| | - Chunyan Wu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Yan-Jin Zhang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA.
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Stine RR, Greenspan LJ, Ramachandran KV, Matunis EL. Coordinate regulation of stem cell competition by Slit-Robo and JAK-STAT signaling in the Drosophila testis. PLoS Genet 2014; 10:e1004713. [PMID: 25375180 PMCID: PMC4222695 DOI: 10.1371/journal.pgen.1004713] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/26/2014] [Indexed: 02/01/2023] Open
Abstract
Stem cells in tissues reside in and receive signals from local microenvironments called niches. Understanding how multiple signals within niches integrate to control stem cell function is challenging. The Drosophila testis stem cell niche consists of somatic hub cells that maintain both germline stem cells and somatic cyst stem cells (CySCs). Here, we show a role for the axon guidance pathway Slit-Roundabout (Robo) in the testis niche. The ligand Slit is expressed specifically in hub cells while its receptor, Roundabout 2 (Robo2), is required in CySCs in order for them to compete for occupancy in the niche. CySCs also require the Slit-Robo effector Abelson tyrosine kinase (Abl) to prevent over-adhesion of CySCs to the niche, and CySCs mutant for Abl outcompete wild type CySCs for niche occupancy. Both Robo2 and Abl phenotypes can be rescued through modulation of adherens junction components, suggesting that the two work together to balance CySC adhesion levels. Interestingly, expression of Robo2 requires JAK-STAT signaling, an important maintenance pathway for both germline and cyst stem cells in the testis. Our work indicates that Slit-Robo signaling affects stem cell function downstream of the JAK-STAT pathway by controlling the ability of stem cells to compete for occupancy in their niche.
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Affiliation(s)
- Rachel R. Stine
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Leah J. Greenspan
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Kapil V. Ramachandran
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Erika L. Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
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4
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Berry DC, Noy N. Signaling by vitamin A and retinol-binding protein in regulation of insulin responses and lipid homeostasis. Biochim Biophys Acta 2012; 1821:168-76. [PMID: 21782034 PMCID: PMC3204314 DOI: 10.1016/j.bbalip.2011.07.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 05/31/2011] [Accepted: 07/06/2011] [Indexed: 12/25/2022]
Abstract
Vitamin A, retinol, circulates in blood bound to serum retinol binding protein (RBP) and is transported into cells by a membrane protein termed stimulated by retinoic acid 6 (STRA6). It was reported that serum levels of RBP are elevated in obese rodents and humans, and that increased level of RBP in blood causes insulin resistance. A molecular mechanism by which RBP can exert such an effect is suggested by the recent discovery that STRA6 is not only a vitamin A transporter but also functions as a surface signaling receptor. Binding of RBP-ROH to STRA6 induces the phosphorylation of a tyrosine residue in the receptor C-terminus, thereby activating a JAK/STAT signaling cascade. Consequently, in STRA6-expressing cells such as adipocytes, RBP-ROH induces the expression of STAT target genes, including SOCS3, which suppresses insulin signaling, and PPARγ, which enhances lipid accumulation. RBP-retinol thus joins the myriad of cytokines, growth factors and hormones which regulate gene transcription by activating cell surface receptors that signal through activation of Janus kinases and their associated transcription factors STATs. This article is part of a Special Issue entitled Retinoid and Lipid Metabolism.
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Affiliation(s)
- Daniel C Berry
- Department of Pharmacology and Nutrition, Case Western Reserve University School of Medicine, Cleveland, OH 44106-4695, USA
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Zhang Y, Song L, Zhao J, Wang L, Kong P, Liu L, Wang M, Qiu L. Protective immunity induced by CpG ODNs against white spot syndrome virus (WSSV) via intermediation of virus replication indirectly in Litopenaeus vannamei. Dev Comp Immunol 2010; 34:418-424. [PMID: 19963004 DOI: 10.1016/j.dci.2009.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 11/30/2009] [Accepted: 11/30/2009] [Indexed: 05/28/2023]
Abstract
The worldwide shrimp culture is beset with diseases mainly caused by white spot syndrome virus (WSSV) and suffered huge economic losses, which bring out an urgent need to develop the novel strategies to better protect shrimps against WSSV. In the present study, CpG-rich plasmid pUC57-CpG, plasmid pUC57 and PBS were employed to pretreat shrimps comparatively to evaluate the protective effects of CpG ODNs on shrimps against WSSV. The survival rates, WSSV copy numbers, and antiviral associated factors (Dicer, Argonaute, STAT and ROS) were detected in Litopenaeus vannamei. There were higher survival proportion, lower WSSV copy numbers, and higher mRNA expression of Dicer and STAT in pUC57-CpG-pretreatment shrimps than those in pUC57- and PBS-pretreatment shrimps after WSSV infection. The Argonaute mRNA expression in pUC57-CpG-, pUC57- and PBS-pretreatment shrimps after WSSV infection was significantly higher than that of shrimps post PBS stimulation on the first day. The ROS levels in pUC57-CpG-pretreatment shrimps post secondary stimulation of PBS were significantly higher than those post WSSV infection on the first day. These results together demonstrated that pUC57-CpG induced partial protective immunity in shrimps against WSSV via intermediation of virus replication indirectly and could be used as a potential candidate in the development of therapeutic agents for disease control of WSSV in L. vannamei.
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Affiliation(s)
- Ying Zhang
- The Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao, Shandong 266071, China
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Luquin E, Larrea E, Civeira MP, Prieto J, Aldabe R. HCV structural proteins interfere with interferon-alpha Jak/STAT signalling pathway. Antiviral Res 2007; 76:194-7. [PMID: 17675168 DOI: 10.1016/j.antiviral.2007.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 06/08/2007] [Accepted: 06/18/2007] [Indexed: 10/23/2022]
Abstract
Hepatitis C virus (HCV) is remarkably efficient at establishing persistent infection. The current treatment with IFN-alpha given alone or in combination with ribavirin is ineffective in eliminating the virus in a large proportion of individuals with chronic hepatitis C. Recent data suggest that HCV blocks IFN-alpha signalling, an effect that facilitates viral persistence. We have used the HCV genomic and subgenomic replicon system to analyze the effect of structural and non-structural viral proteins on the activation of the Jak/STAT pathway and induction of antiviral activity by IFN-alpha. Our results show that IFN-alpha-mediated STAT activation (but not IFN-gamma-stimulated STAT phosphorylation) is blocked in Huh7 cell line containing the genomic replicon, while this is not observed in cells with the subgenomic replicon. In agreement with these findings, the transcriptional activity and the antiviral effect of IFN-alpha were significantly lower in cells harboring the genomic replicon than in cells with the subgenomic replicon. These results indicate that HCV structural proteins play an important role in the escape of HCV from the interferon system.
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Affiliation(s)
- Esther Luquin
- Division of Hepatology and Gene Therapy (CIMA), University of Navarra, Pamplona, Spain
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Yoshiura S, Ohtsuka T, Takenaka Y, Nagahara H, Yoshikawa K, Kageyama R. Ultradian oscillations of Stat, Smad, and Hes1 expression in response to serum. Proc Natl Acad Sci U S A 2007; 104:11292-7. [PMID: 17592117 PMCID: PMC1899192 DOI: 10.1073/pnas.0701837104] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Serum response has been used as a model for studying signaling transduction for many biological events such as cell proliferation and survival. Although expression of many genes is up- or down-regulated after serum stimulation, the Notch effector Hes1 displays oscillatory response. However, the precise mechanism and biological significance of this oscillation remain to be determined. Here, we identified serum-induced ultradian oscillators, including molecules in Stat and Smad signaling. Stat and Smad oscillations involve activation of Stat3 and Smad1 and delayed negative feedback by their inhibitors Socs3 and Smad6, respectively. Moreover, Stat oscillations induce oscillatory expression of Hes1 by regulating its half-life, and loss of Hes1 oscillations leads to G(1) phase retardation of the cell cycle. These results indicate that coupled Stat and Hes1 oscillations are important for efficient cell proliferation and provide evidence that expression modes of signaling molecules affect downstream cellular events.
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Affiliation(s)
- Shigeki Yoshiura
- *Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
- Kyoto University Graduate School of Biostudies, Kyoto 606-8502, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kyoto 606-8507, Japan
| | - Toshiyuki Ohtsuka
- *Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kyoto 606-8507, Japan
| | - Yoshiko Takenaka
- Department of Physics, Kyoto University Graduate School of Science, Kyoto 606-8502, Japan; and
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kyoto 606-8502, Japan
| | - Hiroki Nagahara
- Department of Physics, Kyoto University Graduate School of Science, Kyoto 606-8502, Japan; and
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kyoto 606-8502, Japan
| | - Kenichi Yoshikawa
- Department of Physics, Kyoto University Graduate School of Science, Kyoto 606-8502, Japan; and
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kyoto 606-8502, Japan
| | - Ryoichiro Kageyama
- *Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kyoto 606-8507, Japan
- To whom correspondence should be addressed. E-mail:
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Zaheer S, Wu Y, Bassett J, Yang B, Zaheer A. Glia Maturation Factor Regulation of STAT Expression: A Novel Mechanism in Experimental Autoimmune Encephalomyelitis. Neurochem Res 2007; 32:2123-31. [PMID: 17551829 DOI: 10.1007/s11064-007-9383-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Accepted: 05/09/2007] [Indexed: 10/23/2022]
Abstract
Inflammatory cytokines are implemented in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. We previously demonstrated that glia maturation factor (GMF), a brain protein, isolated, sequenced and cloned in our laboratory, induce expression of proinflammatory cytokine/chemokine in the central nervous system (CNS). We found GMF-deficient (knockout) mice relatively resistant to EAE development after immunization with encephalitogenic MOG peptide 35-55. Consistent with these findings, the expression of proinflammatory cytokines in CNS of mice with EAE differed profoundly between wild type and GMF-knockout mice. In the present study we examined the expressions of six murine signal transducers and activators of transcription (STATs) genes, which are known to regulate the cytokine-dependent signal transduction pathways in autoimmune inflammation. The expressions of STATs genes were evaluated in the brains and spinal cords of wild type and GMF-knockout mice at the peak of EAE by quantitative real-time RT-PCR. Compared to GMF-knockout mice, the expressions of STAT1, STAT2, STAT3, STAT4, STAT5, and STAT6 genes were significantly (P < 0.001) upregulated in the wild type mice exhibiting EAE symptoms. The results are consistent with the diminished development of EAE in the GMF-knockout mice. A significant suppression of STATs expression in GMF-knockout mice suggests GMF as an upstream effector of JAK/STAT signaling.
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Affiliation(s)
- Smita Zaheer
- Veterans Affairs Medical Center, Iowa City, IA, USA.
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Samaan A, Mahana W. Constitutive and induced activation of JAK/Stat pathway in leukemogenic and asymptomatic human T-cell lymphoptropic virus type 1 (HTLV-1) transformed rabbit cell lines. Immunol Lett 2007; 109:113-9. [PMID: 17368812 DOI: 10.1016/j.imlet.2007.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Accepted: 01/28/2007] [Indexed: 01/28/2023]
Abstract
We have shown that Vav and C-cbl are activated in the leukemogenic HTLV-I transformed rabbit T cell line RH/K34 but not in the asymptomatic one RH/K30. We extended these observations and investigated the activation of JAKs (Janus Kinase) and the STATs (signal transducers and activators of transcription) pathway in these cell lines. We found that Tyk2 and Stat3 are constitutively tyrosine phosphorylated in the leukemogenic cell line. Phosphorylation of Tyk2 can be induced in RH/K30 by treatment with IL-10, interferon alpha (INFalpha) and by the supernatant of RH/K34 which contain both these cytokines. Stat3 tyrosine phosphorylation can be induced in RH/K30 by treatment with IL-10. Transfection of RL-5, a rabbit T-cell line, with the RH/K34 viral clone transiently increased the expression of serine/threonine phosphorylated Stat3. Differences were also observed on induced Stat5 phosphorylation. These results highlight the relation between the virulence of HTLV-I and the activation of the Jak/Stat pathway.
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Affiliation(s)
- Angela Samaan
- Groupe d'Immunologie Microbienne, Université de Bretagne Occidentale, IUT de Quimper, 2 Rue de l'Université, 29334 Quimper Cedex, France
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Larrea E, Aldabe R, Molano E, Fernandez-Rodriguez CM, Ametzazurra A, Civeira MP, Prieto J. Altered expression and activation of signal transducers and activators of transcription (STATs) in hepatitis C virus infection: in vivo and in vitro studies. Gut 2006; 55:1188-96. [PMID: 16120756 PMCID: PMC1856287 DOI: 10.1136/gut.2005.070060] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Signal transducers and activators of transcription (STATs) play a critical role in antiviral defence. STAT3 is also important in cell protection against inflammatory damage. STAT proteins are activated by interferons and by hepatoprotective cytokines of the interleukin 6 superfamily, including cardiotrophin 1. METHODS We analysed the status of STATs in hepatitis C virus (HCV) infected livers and the relationship between expression and activation of STATs and HCV replication in Huh7 cells transfected with HCV genomic replicon. RESULTS STAT3alpha expression was reduced in HCV infected livers showing an inverse correlation with serum alanine aminotransferase. In patients with HCV infection, nuclear staining for phosphorylated STAT3 was faint in parenchymal cells (although conspicuous in infiltrating leucocytes), in contrast with strong nuclear staining in hepatocytes from control livers. Expression and activation of STAT1 (a factor activated by both interferon (IFN)-alpha and IFN-gamma) were increased in HCV infected livers, particularly in those with high inflammatory activity. Conversely, phosphorylated STAT2 (a factor selectively activated by IFN-alpha) was undetectable in livers with HCV infection, a finding that was associated with marked downregulation of the two functional subunits of the IFN-alpha receptor. HCV replication in Huh7 cells caused STAT3alpha downregulation and blocked STAT3 phosphorylation by either IFN-alpha or cardiotrophin 1. HCV replication in Huh7 cells also inhibited STAT1 and STAT2 activation by IFN-alpha while there was no impairment of STAT1 phosphorylation by the proinflammatory cytokine IFN-gamma. CONCLUSIONS STAT3 is downregulated in HCV infected livers and in Huh7 cells bearing the full length HCV replicon. HCV replication is associated with impaired Jak-STAT signalling by antiviral and cytoprotective cytokines. These effects may favour viral replication while facilitating the progression of liver disease.
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Affiliation(s)
- E Larrea
- Division of Hepatology and Gene Therapy, Clínica Universitaria, Pamplona, Spain
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Wu L, Zhao L, Zheng Q, Shang F, Wang X, Wang L, Lang B. Simvastatin attenuates hypertrophic responses induced by cardiotrophin-1 via JAK–STAT pathway in cultured cardiomyocytes. Mol Cell Biochem 2006; 284:65-71. [PMID: 16534557 DOI: 10.1007/s11010-005-9014-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Accepted: 09/21/2005] [Indexed: 11/28/2022]
Abstract
UNLABELLED Cardiotrophin-1 (CT-1) is a cytokine involved in the growth and survival of cardiac cells via activation of the Janus activated kinase/signal transducer activator of transcription (JAK/STAT). Statins, 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, have effects that extend beyond cholesterol reduction and inhibit vascular smooth muscle cell (VSMC) proliferation and cardiac hypertrophy. However, whether stains also can inhibitin vitromyocardial hypertrophy or not still remains elusive. The purpose of this study was to explore the effects of simvastatin on the hypertrophy of cultured rat cardiomyocytes induced by CT-1 and to investigate whether this effect was mediated via JAK-STAT signaling pathway. METHODS AND RESULTS Primary cardiomyocytes from 2-day-old (P2) rats were cultured, stimulated with CT-1, and treated with various concentration of simvastatin. Incorporation of [(3)H] leucine, reverse transcription-polymerase chain reaction and western blotting techniques were used to investigate cardiacmyocyte size, ANP mRNA and JAK-STAT protein expression. Simvastatin was proved, in a dose-independent manner, to decrease cardiacmyocytes size as well as protein synthesis, and inhibit ANP mRNA synthesis and JAK-STAT protein expression induced by CT-1 in cardiacmyocytes. CONCLUSION These results suggest that simvastatin can ameliorate cardiacmyocytes hypertrophyin vitrovia JAK-STAT signaling pathways. The present study provides a novel understanding and alternative therapeutic strategy for cardiac hypertrophy.
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Affiliation(s)
- LiJun Wu
- Institute Hypertension, Department of Cardiology, TangDu Hospital, Fourth Military Medical University, Xi'an 710038, PR China.
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Boonyaratanakornkit JB, Cogoli A, Li CF, Schopper T, Pippia P, Galleri G, Meloni MA, Hughes-Fulford M. Key gravity‐sensitive signaling pathways drive T‐cell activation. FASEB J 2005; 19:2020-2. [PMID: 16210397 DOI: 10.1096/fj.05-3778fje] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Returning astronauts have experienced altered immune function and increased vulnerability to infection during spaceflights dating back to Apollo and Skylab. Lack of immune response in microgravity occurs at the cellular level. We analyzed differential gene expression to find gravity-dependent genes and pathways. We found inhibited induction of 91 genes in the simulated freefall environment of the random positioning machine. Altered induction of 10 genes regulated by key signaling pathways was verified using real-time RT-PCR. We discovered that impaired induction of early genes regulated primarily by transcription factors NF-kappaB, CREB, ELK, AP-1, and STAT after crosslinking the T-cell receptor contributes to T-cell dysfunction in altered gravity environments. We have previously shown that PKA and PKC are key early regulators in T-cell activation. Since the majority of the genes were regulated by NF-kappaB, CREB, and AP-1, we studied the pathways that regulated these transcription factors. We found that the PKA pathway was down-regulated in vg. In contrast, PI3-K, PKC, and its upstream regulator pLAT were not significantly down-regulated by vectorless gravity. Since NF-kappaB, AP-1, and CREB are all regulated by PKA and are transcription factors predicted by microarray analysis to be involved in the altered gene expression in vectorless gravity, the data suggest that PKA is a key player in the loss of T-cell activation in altered gravity.
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