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Sun Z, Yao X, Ding X, Li X, Tian X. MicroRNAs and their signaling pathway in mycosis fungoides. Medicine (Baltimore) 2022; 101:e29248. [PMID: 35758353 PMCID: PMC9276080 DOI: 10.1097/md.0000000000029248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 04/18/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Oncogenic microRNAs, a kind of stable epigenetic inhibitors, often deregulated in Mycosis fungoides (MF) which affect the skin and tend to transform and spread. RESULTS Previous studies investigating the de-expression of microRNA in MF patients skin biopsies identified that they were not only regulated by signaling pathway, but also regulated other signaling pathway. Furthermore, studies have elucidated the molecular mechanisms of the STAT signaling pathway that can promote a great diversity of miRNA expression via cytokine binding receptors, activating Janus kinase-3 and STAT proteins. But some non-STAT signaling pathway with mircoRNA de-expression in MF was incomplete. CONCLUSION Taken together, these studies demonstrate that microRNA may be used as the prognosis, progression and diagnose of MF, as they can not only control MF cell proliferation, but also induce MF cell apoptosis.
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Kim M, Morales LD, Lee CJ, Olivarez SA, Kim WJ, Hernandez J, Mummidi S, Jenkinson C, Tsin AT, Jang IS, Slaga TJ, Kim DJ. Overexpression of TC-PTP in murine epidermis attenuates skin tumor formation. Oncogene 2020; 39:4241-4256. [PMID: 32286519 PMCID: PMC7244373 DOI: 10.1038/s41388-020-1282-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 03/18/2020] [Accepted: 03/23/2020] [Indexed: 02/07/2023]
Abstract
T-cell protein tyrosine phosphatase (TC-PTP), encoded by Ptpn2, has been shown to function as a tumor suppressor during skin carcinogenesis. In the current study, we generated a novel epidermal-specific TC-PTP-overexpressing (K5HA.Ptpn2) mouse model to show that TC-PTP contributes to the attenuation of chemically induced skin carcinogenesis through the synergistic regulation of STAT1, STAT3, STAT5, and PI3K/AKT signaling. We found overexpression of TC-PTP increased epidermal sensitivity to DMBA-induced apoptosis and it decreased TPA-mediated hyperproliferation, coinciding with reduced epidermal thickness. Inhibition of STAT1, STAT3, STAT5, or AKT reversed the effects of TC-PTP overexpression on epidermal survival and proliferation. Mice overexpressing TC-PTP in the epidermis developed significantly reduced numbers of tumors during skin carcinogenesis and presented a prolonged latency of tumor initiation. Examination of human papillomas and squamous cell carcinomas (SCCs) revealed that TC-PTP expression was significantly reduced and TC-PTP expression was inversely correlated with the increased grade of SCCs. Our findings demonstrate that TC-PTP is a potential therapeutic target for the prevention of human skin cancer given that it is a major negative regulator of oncogenic signaling.
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Affiliation(s)
- Mihwa Kim
- Department of Molecular Science, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Liza D Morales
- Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Cheol Jung Lee
- Department of Molecular Science, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Serena A Olivarez
- Department of Molecular Science, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Woo Jin Kim
- School of Mathematical and Statistical Sciences, College of Sciences, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Joselin Hernandez
- Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Srinivas Mummidi
- Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Christopher Jenkinson
- Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Andrew T Tsin
- Department of Molecular Science, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Ik-Soon Jang
- Division of Bioconvergence Analysis, Korea Basic Science Institute, Daejeon, 305-333, Republic of Korea
| | - Thomas J Slaga
- Department of Pharmacology, School of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Dae Joon Kim
- Department of Molecular Science, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA.
- Department of Human Genetics, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, USA.
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Ai G, Shao X, Meng M, Song L, Qiu J, Wu Y, Zhou J, Cheng J, Tong X. Epidermal growth factor promotes proliferation and maintains multipotency of continuous cultured adipose stem cells via activating STAT signal pathway in vitro. Medicine (Baltimore) 2017; 96:e7607. [PMID: 28746211 PMCID: PMC5627837 DOI: 10.1097/md.0000000000007607] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
This study aimed to investigate the effects of epidermal growth factor (EGF) on the proliferation and differentiation of adipose stem cells (ASC) during the repeated passaging and probe the underlying signal pathway. Results showed that the Ki67 positive rate remained at a high level, the number of ASCs in G0/G1 phase reduced significantly, but ASCs in G2/M phase and S phase increased markedly in ASCs treated with EGF when compared with ASCs without EGF treatment, indicating that EGF made more ASCs in proliferation phase. The adipogenic capability of ASCs without EGF was compromised when compared with that of ASCs after EGF treatment, although significant difference was not observed. The osteogenic and chondrogenic potencies increased significantly in ASC with EGF treatment indicating EGF could maintain differentiative capacity of ASCs. Gene Set Enrichment Analysis showed EGF upregulated the expression of molecules in the epithelial mesenchymal transition and G2/M checkpoint signal pathways. GeneMANIA database analysis indicated the network interaction between EGF and STAT. EGF receptor (EGFR) inhibitor and STAT3 inhibitor were independently used to validate the role of both pathways in these effects. After inhibition of EGFR or STAT3, the proliferation of ASCs was significantly inhibited, and Western blotting showed EGF was able to markedly increase the expression of EGFR and STAT3. These findings suggest EGF not only promotes the proliferation of ASCs and delays their senescence, but also maintains the differentiation potency of ASCs, which are related to the EGF-induced activation of STAT signal pathway.
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Affiliation(s)
- Guihai Ai
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Xiaowen Shao
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Meng Meng
- Shanghai First Maternity and Infant Hospital
| | - Liwen Song
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Jin Qiu
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Yi Wu
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Jianhong Zhou
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Jiajing Cheng
- Department of Obstetrics and Gynecology, Shanghai Tenth People's Hospital
| | - Xiaowen Tong
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
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Abstract
Tissue development and homeostasis are governed by the actions of stem cells. Multipotent cells are capable of self-renewal during the course of one's lifetime. The accurate and appropriate regulation of stem cell functions is absolutely critical for normal biological activity. Several key developmental or signaling pathways have been shown to play essential roles in this regulatory capacity. Specifically, the Janus-activated kinase/signal transducer and activator of transcription, Hedgehog, Wnt, Notch, phosphatidylinositol 3-kinase/phosphatase and tensin homolog, and nuclear factor-κB signaling pathways have all been shown experimentally to mediate various stem cell properties, such as self-renewal, cell fate decisions, survival, proliferation, and differentiation. Unsurprisingly, many of these crucial signaling pathways are dysregulated in cancer. Growing evidence suggests that overactive or abnormal signaling within and among these pathways may contribute to the survival of cancer stem cells (CSCs). CSCs are a relatively rare population of cancer cells capable of self-renewal, differentiation, and generation of serially transplantable heterogeneous tumors of several types of cancer.
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Affiliation(s)
- William H. Matsui
- The Matsui Laboratory, The Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD
- Correspondence: William H. Matsui, The Johns Hopkins University School of Medicine, Baltimore, MD 21287 (e-mail: )
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Gaskin CM, Patrie JT, Hanshew MD, Boatman DM, McWey RP. Impact of a Reading Priority Scoring System on the Prioritization of Examination Interpretations. AJR Am J Roentgenol 2016; 206:1031-9. [PMID: 26999578 DOI: 10.2214/AJR.15.14837] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our institution implemented a read priority scoring system to combat the known limitations of traditional methods for the prioritization of examination interpretations by radiologists. We aimed to determine the impact on report turnaround time (RTAT) and RTAT variability. MATERIALS AND METHODS On examination completion, technologists entered a read priority score (1-9) using provided definitions. We retrospectively reviewed the median RTAT and RTAT variability (i.e., interquartile range length) for radiology examinations (n = 615,541; 2011-2014). We used Spearman correlation coefficients to determine the relationships between read priority scores and the median RTAT and the RTAT variability by year. We compared median RTAT and RTAT variability between early (2011) versus late (2012-2014) adoption phases using distribution-free random permutation tests. RESULTS Ranked correlations showed yearly improvement, leading to a near-perfect ranking of median RTAT (r = 0.98, p < 0.001) and a perfect ranking of RTAT variability (r = 1.00, p < 0.001) by nine levels of priority. Eight of the nine priority levels showed a reduction in median RTAT between the early and late phases, and the three most urgent levels--that is, 1, 2, and 3--improved by 23%, 5%, and 70% (all, p < 0.001), respectively. Only one priority level (4, defined as outpatient urgent [8% of studies]) showed significant worsening by 15% (p < 0.001). The three most urgent levels of priority also showed improvements in RTAT variability (61%, 17%, 71%, respectively; all, p < 0.01). Only the lowest level of priority (9) exhibited a significant worsening in RTAT variability by 9% (p < 0.01). CONCLUSION A reading priority scoring system with defined clinical scenarios yielded desirable prioritization of examination interpretations by radiologists as evidenced by appropriate and improved stratification of RTATs and RTAT variability.
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Jung JE, Karatas H, Liu Y, Yalcin A, Montaner J, Lo EH, van Leyen K. STAT-dependent upregulation of 12/15-lipoxygenase contributes to neuronal injury after stroke. J Cereb Blood Flow Metab 2015; 35:2043-51. [PMID: 26174325 PMCID: PMC4671126 DOI: 10.1038/jcbfm.2015.169] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 06/12/2015] [Accepted: 06/15/2015] [Indexed: 01/20/2023]
Abstract
Oxidative stress is a major brain injury mechanism after ischemic stroke. 12/15-lipoxygenase (12/15-LOX) is a key mediator of oxidative stress, contributing to neuronal cell death and vascular leakage. Nonetheless, the mechanism leading to its upregulation is currently unknown. We show here that Signal Transducers and Activators of Transcription (STATs), specifically STAT6 and possibly STAT1, increase transcription of 12/15-LOX in neuronal cells. Both p-STAT6 and -1 bound to specific STAT binding sites in the mouse 12/15-LOX promoter. Small interfering RNA (siRNA) knockdown showed STAT6 to be the dominant regulator, reducing 12/15-LOX promoter activation and cell death in oxidatively stressed HT22 cells. STAT6 siRNA efficiently prevented the increase of 12/15-LOX in murine primary neurons, both after induction of oxidative stress and after oxygen-glucose deprivation. Early activation of STAT6 and STAT1 in mice was consistent with a role in regulating 12/15-LOX in focal ischemia. Brains of human stroke patients showed increased p-STAT6 and p-STAT1 in the peri-infarct region, along with 12/15-LOX and markers of apoptosis. These results link STAT6 and STAT1 to the 12/15-LOX damage pathway and suggest disregulation of STAT-dependent transcription as injury mechanism in stroke. Selectively targeting STATs may thus be a novel therapeutic approach to reducing brain injury after a stroke.
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Affiliation(s)
- Joo Eun Jung
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Hulya Karatas
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Yu Liu
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Ayfer Yalcin
- Department of Biochemistry, Faculty of Pharmacy, Ege University, Bornova, Izmir, Turkey.,Biruni University, Faculty of Pharmacy, Istanbul, Turkey
| | - Joan Montaner
- Laboratorio de Investigación Neurovascular Hospital Vall d'Hebron, Barcelona, Spain
| | - Eng H Lo
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Klaus van Leyen
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
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Plisov S, Wang H, Tarasova N, Sharma N, Perantoni AO. Protein/peptide transduction in metanephric explant culture. Methods Mol Biol 2014; 1092:255-67. [PMID: 24318826 PMCID: PMC7670307 DOI: 10.1007/978-1-60327-292-6_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Indexed: 01/20/2023]
Abstract
While gene targeting methods have largely supplanted cell/explant culture models for studying developmental processes, they have not eliminated the need for or value of such approaches in the investigator's technical arsenal. Explant culture models, such as those devised for the metanephric kidney and its progenitors, remain invaluable as tools for screening regulatory factors involved in tissue induction or in the inhibition of progenitor specification. Thus, some factors capable of inducing tissue condensations or nephronic tubule formation in explants of metanephric mesenchyme have been identified through direct treatment of cultures rather than lengthy genetic engineering in animals. Unfortunately, renal progenitors are largely refractory to most contemporary methods for gene manipulation, including transfection and viral transduction, so the applications of explant culture have been rather limited. However, methods for protein or peptide transduction offer greatly improved efficiencies for uptake and expression/regulation of proteins within cells and tissues. Biologically active TAT- or penetratin-fusion proteins/peptides are readily taken up by most cells in metanephric explants or monolayer cultured cells (Plisov et al., J Am Soc Nephrol 16:1632-1644, 2005; Osafune et al., Development 133:151-161, 2006; Wang et al., Cell Signal 22:1717-1726, 2010; Tanigawa, Dev Biol 352:58-69, 2011), allowing a direct functional evaluation of theoretically any protein, including biologically active enzymes and transcription factors, or any targeted interactive domain within a protein.
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Affiliation(s)
- Sergey Plisov
- Frederick National Lab of Cancer Research, NCI, NIH, Frederick, MD, USA
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Abstract
Aberrant activation of the JAK/STAT pathway has been reported in a variety of disease states, including inflammatory conditions, hematologic malignancies, and solid tumors. For instance, a large proportion of patients with myeloproliferative neoplasms (MPN) carry the acquired gain-of-function JAK2 V617F somatic mutation. This knowledge has dramatically improved our understanding of the pathogenesis of MPNs and has facilitated the development of therapeutics capable of suppressing the constitutive activation of the JAK/STAT pathway, now recognized as a common underlying biologic abnormality in MPNs. Ruxolitinib is an oral JAK1 and JAK2 inhibitor that has recently been approved for the treatment of myelofibrosis and has been tested against other hematologic malignancies. A series of agents with different specificities against different members of the JAK family of proteins is currently undergoing evaluation in clinical trials for patients with MPNs, lymphoma, and solid tumors such as breast or pancreatic cancer. Despite the significant clinical activity exhibited by these agents in myelofibrosis, some patients fail to respond or progress during JAK kinase inhibitor therapy. Recent reports have shed light into the mechanisms of resistance to JAK inhibitor therapy. Several approaches hold promise to overcome such resistance.
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Affiliation(s)
- Alfonso Quintás-Cardama
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Dickensheets H, Sheikh F, Park O, Gao B, Donnelly RP. Interferon-lambda (IFN-λ) induces signal transduction and gene expression in human hepatocytes, but not in lymphocytes or monocytes. J Leukoc Biol 2013; 93:377-85. [PMID: 23258595 PMCID: PMC3579021 DOI: 10.1189/jlb.0812395] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [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: 08/13/2012] [Revised: 10/26/2012] [Accepted: 12/01/2012] [Indexed: 01/14/2023] Open
Abstract
This study compared the ability of IFN-α and IFN-λ to induce signal transduction and gene expression in primary human hepatocytes, PBLs, and monocytes. IFN-α drug products are widely used to treat chronic HCV infection; however, IFN-α therapy often induces hematologic toxicities as a result of the broad expression of IFNARs on many cell types, including most leukocytes. rIFN-λ1 is currently being tested as a potential alternative to IFN-α for treating chronic HCV. Although IFN-λ has been shown to be active on hepatoma cell lines, such as HepG2 and Huh-7, its ability to induce responses in primary human hepatocytes or leukocytes has not been examined. We found that IFN-λ induces activation of Jak/STAT signaling in mouse and human hepatocytes, and the ability of IFN-λ to induce STAT activation correlates with induction of numerous ISGs. Although the magnitude of ISG expression induced by IFN-λ in hepatocytes was generally lower than that induced by IFN-α, the repertoire of regulated genes was quite similar. Our findings demonstrate that although IFN-α and IFN-λ signal through distinct receptors, they induce expression of a common set of ISGs in hepatocytes. However, unlike IFN-α, IFN-λ did not induce STAT activation or ISG expression by purified lymphocytes or monocytes. This important functional difference may provide a clinical advantage for IFN-λ as a treatment for chronic HCV infection, as it is less likely to induce the leukopenias that are often associated with IFN-α therapy.
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Affiliation(s)
- Harold Dickensheets
- Division of Therapeutic Proteins, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Bethesda, Maryland, USA; and
| | - Faruk Sheikh
- Division of Therapeutic Proteins, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Bethesda, Maryland, USA; and
| | - Ogyi Park
- Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Bin Gao
- Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Raymond P. Donnelly
- Division of Therapeutic Proteins, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Bethesda, Maryland, USA; and
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Vahedi G, Poholek A, Hand TW, Laurence A, Kann Y, O’Shea JJ, Hirahara K. Helper T-cell identity and evolution of differential transcriptomes and epigenomes. Immunol Rev 2013; 252:24-40. [PMID: 23405893 PMCID: PMC3577092 DOI: 10.1111/imr.12037] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [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] [Indexed: 12/12/2022]
Abstract
CD4(+) T cells are critical for the elimination of an immense array of microbial pathogens. Among the ways they accomplish this task is to generate progeny with specialized, characteristic patterns of gene expression. From this perspective, helper cells can be viewed as pluripotent precursors that adopt distinct cell fates. Although there are aspects of helper cell differentiation that can be modeled as a classic cell fate commitment, CD4(+) T cells also maintain considerable flexibility in their transcriptional program. This makes sense in terms of host defense, but raises the question of how these remarkable cells balance both these requirements, a high degree of specific gene expression and the capacity for plasticity. In this review, we discuss recent advances in our understanding of CD4(+) T-cell specification, focusing on how genomic perspectives have influenced our views of these processes. The relative contributions of sensors of the cytokine milieu, especially the signal transducer and activator of transcription family transcription factors, 'master regulators', and other transcription factors are considered as they relate to the helper cell transcriptome and epigenome.
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Affiliation(s)
- Golnaz Vahedi
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Amanda Poholek
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Timothy W. Hand
- Laboratory of parasitic diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Arian Laurence
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Yuka Kann
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - John J. O’Shea
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
| | - Kiyoshi Hirahara
- Lymphocyte Cell Biology Section, Molecular Immunology and Inflammation Branch, National Institutes of Arthritis, and Musculoskeletal and Skin Diseases, Bethesda, MD, USA
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Kang K, Robinson GW, Hennighausen L. Comprehensive meta-analysis of Signal Transducers and Activators of Transcription ( STAT) genomic binding patterns discerns cell-specific cis-regulatory modules. BMC Genomics 2013; 14:4. [PMID: 23324445 PMCID: PMC3564941 DOI: 10.1186/1471-2164-14-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 01/01/2013] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Cytokine-activated transcription factors from the STAT (Signal Transducers and Activators of Transcription) family control common and context-specific genetic programs. It is not clear to what extent cell-specific features determine the binding capacity of seven STAT members and to what degree they share genetic targets. Molecular insight into the biology of STATs was gained from a meta-analysis of 29 available ChIP-seq data sets covering genome-wide occupancy of STATs 1, 3, 4, 5A, 5B and 6 in several cell types. RESULTS We determined that the genomic binding capacity of STATs is primarily defined by the cell type and to a lesser extent by individual family members. For example, the overlap of shared binding sites between STATs 3 and 5 in T cells is greater than that between STAT5 in T cells and non-T cells. Even for the top 1,000 highly enriched STAT binding sites, ~15% of STAT5 binding sites in mouse female liver are shared by other STATs in different cell types while in T cells ~90% of STAT5 binding sites are co-occupied by STAT3, STAT4 and STAT6. In addition, we identified 116 cis-regulatory modules (CRM), which are recognized by all STAT members across cell types defining a common JAK-STAT signature. Lastly, in liver STAT5 binding significantly coincides with binding of the cell-specific transcription factors HNF4A, FOXA1 and FOXA2 and is associated with cell-type specific gene transcription. CONCLUSIONS Our results suggest that genomic binding of STATs is primarily determined by the cell type and further specificity is achieved in part by juxtaposed binding of cell-specific transcription factors.
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Affiliation(s)
- Keunsoo Kang
- Laboratory of Genetics and Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Drive, Bethesda, MD, 20892-0822, USA
| | - Gertraud W Robinson
- Laboratory of Genetics and Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Drive, Bethesda, MD, 20892-0822, USA
| | - Lothar Hennighausen
- Laboratory of Genetics and Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 8 Center Drive, Bethesda, MD, 20892-0822, USA
- National Department of Nanobiomedical Science and WCU Research Center of Nanobiomedical Science, Dankook University, Cheonan, Chungnam, 330-714, Republic of Korea
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Wu Q, Wang W, Li S, Nagarkatti P, Nagarkatti M, Windust A, Wang XL, Tang D, Cui T. American ginseng inhibits vascular smooth muscle cell proliferation via suppressing Jak/ Stat pathway. J Ethnopharmacol 2012; 144:782-785. [PMID: 23041701 PMCID: PMC4109065 DOI: 10.1016/j.jep.2012.09.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/10/2012] [Accepted: 09/06/2012] [Indexed: 06/01/2023]
Abstract
UNLABELLED ETHNOPHARMCOLOGICAL RELEVANCE: Ginseng, a folk medicine which has been used for thousands of years in Asia, has been promoted for the treatment or prevention of health problems including cardiovascular disease. However, the molecular mechanism of ginseng-induced cardiovascular protection is unclear. Thus, we investigated signaling mechanism by which American ginseng inhibits vascular smooth muscle cell (VSMC) proliferation, a key feature of diverse vascular disease. MATERIALS AND METHODS A standardized crude extract of American ginseng was supplied by the National Research Council of Canada, Institute for National Measurement Standards. Rat aortic smooth muscle cells (RASMCs) were exposed to fetal bovine serum (FBS), platelet derived growth factor (PDGF), insulin, or angiotensin II (Ang II) to induce proliferation that was examined by measuring DNA synthesis and cell numbers. Western blot was applied to determine the activations of Jak, Stat, Akt, and ERK. RESULTS American ginseng inhibited RASMC proliferation induced by FBS, PDGF, insulin or Ang II. American ginseng slightly increased both basal and FBS-, PDGF- or Ang II-induced activities of Akt and ERK in RASMCs; however, it dramatically inhibited the activation of Jak2 and Stat3. CONCLUSION These results demonstrate that American ginseng inhibits VSMC proliferation through suppressing the Jak/Stat pathway.
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Affiliation(s)
- Qi Wu
- Shandong University Qilu Hospital Research Center for Cell Therapy, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital of Shandong University, Jinan 250012, China
- Department of Anatomy, Shandong University School of Medicine, Jinan 2500012, China
| | - Wenjuan Wang
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC 29208, USA
| | - Siying Li
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC 29208, USA
| | - Prakash Nagarkatti
- Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC 29208, USA
| | - Mitzi Nagarkatti
- Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC 29208, USA
| | | | - Xing Li Wang
- Shandong University Qilu Hospital Research Center for Cell Therapy, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital of Shandong University, Jinan 250012, China
| | - Dongqi Tang
- Shandong University Qilu Hospital Research Center for Cell Therapy, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital of Shandong University, Jinan 250012, China
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL 32610-0275, USA
| | - Taixing Cui
- Shandong University Qilu Hospital Research Center for Cell Therapy, Key Laboratory of Cardiovascular Remodeling and Function Research, Qilu Hospital of Shandong University, Jinan 250012, China
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC 29208, USA
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Abstract
Expression of cytokine-regulated signal transducer and activator of transcription (STAT) proteins was histochemically assessed in patients diagnosed as having Hashimoto's disease or focal lymphocytic thyroiditis (n = 10). All surgical specimens showed histological features of lymphocytic thyroiditis, including a diffuse infiltration with mononuclear cells and an incomplete loss of thyroid follicles, resulting in the destruction of glandular tissue architecture. Immunohistochemical analysis demonstrated differential expression patterns of the various members of the STAT transcription factors examined, indicating that each member of this conserved protein family has its distinct functions in the development of the disease. Using an antibody that specifically recognized the phosphorylated tyrosine residue in position 701, we detected activated STAT1 dimers in numerous germinal macrophages and infiltrating lymphocytes as well as in oncocytes. In contrast, STAT3 expression was restricted to epithelial cells and showed a clear colocalization with the antiapoptotic protein Bcl-2. Moreover, expression of phospho-STAT3 was associated with low levels of stromal fibrosis, suggesting that STAT3 serves as a protective factor in the remodeling of the inflamed thyroid gland. Phospho-STAT5 immunoreactivity was detected in numerous infiltrating cells of hematopoietic origin and, additionally, in hyperplastic follicular epithelia. This tissue distribution demonstrated that activated STAT5 molecules participate in both lymphocytopoiesis and possibly also in the buildup of regenerating thyroid follicles. Taken together, the cell-type-specific expression patterns of STAT proteins in human lymphocytic thyroiditis reflect their distinct and partially antagonistic roles in orchestrating the balance between degenerating and regenerating processes within a changing cytokine environment.
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Affiliation(s)
- Julia Staab
- Klinik für Psychosomatische Medizin und Psychotherapie, Georg-August-Universität, Von-Siebold-Str. 5, 37075 Göttingen, Germany
| | - Peter J. Barth
- Gerhard-Domagk-Institut für Pathologie, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Thomas Meyer
- Klinik für Psychosomatische Medizin und Psychotherapie, Georg-August-Universität, Von-Siebold-Str. 5, 37075 Göttingen, Germany
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14
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Abstract
Suppressors of cytokine signaling 3 (SOCS3) has been shown to be an important and non-redundant feedback inhibitor of several cytokines including leukemia inhibitory factor, IL-6, IL-11, Ciliary neurotrophic factor (CNTF), leptin, and granulocyte colony-stimulating factor (G-CSF). Loss of SOCS3 in vivo has profound effects on placental development, inflammation, fat-induced weight gain, and insulin sensitivity. SOCS3 expression is induced by Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling and it then binds to specific cytokine receptors (including gp130, G-CSF, and leptin receptors). SOCS3 then inhibits JAK/STAT signaling in two distinct ways. First, SOCS3 is able to directly inhibit the catalytic activity of JAK1, JAK2, or TYK2 while remaining bound to the cytokine receptor. Second, SOCS3 recruits elongins B/C and Cullin5 to generate an E3 ligase that ubiquitinates both JAK and cytokine receptor targeting them for proteasomal degradation. Detailed in vivo studies have revealed that SOCS3 action not only limits the duration of cytokine signaling to prevent overactivity but it is also important in maintaining the specificity of cytokine signaling.
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Affiliation(s)
- Jeffrey J Babon
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia.
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15
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Naylor H, Woloschuk DMM, Fitch P, Miller S. Retrospective audit of medication order turnaround time after implementation of standardized definitions. Can J Hosp Pharm 2012; 64:346-53. [PMID: 22479087 DOI: 10.4212/cjhp.v64i5.1070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Standardizing the interpretation of "stat", "emergent", "urgent", and "now" medication orders can improve patient safety. However, the effect of implementing standardized definitions on the turnaround time for medication orders in hospital pharmacy dispensaries has not been studied. OBJECTIVES To examine the effects of using formal definitions for "stat", "emergent", "urgent", and "now" on turnaround time for medication orders within a pharmacy dispensary. METHODS Definitions for "stat", "emergent", "urgent", and "now" orders, as well as for "turnaround time", were developed from the formal literature and the grey literature. The definitions were implemented by educating all pharmacy staff. Retrospective audits of turnaround time were conducted at baseline (for all orders over a 1-month period) and after implementation of the definitions (for a total of 28 days over a 3-month period). Health records and medication orders were used to calculate time from prescribing to administration (total turnaround time) and time from prescribing to departure from the dispensary (dispensary turnaround time). Differences between total and dispensary turnaround times were compared with nonparametric statistics. RESULTS During the baseline audit period, 84 (1.1%) of 7787 orders were identified as "stat", "emergent", "urgent", or "now". After implementation of the formal definitions, 142 (2.6%) of 5365 orders were identified by one of these terms. The percentage of orders meeting the target dispensary turnaround time of less than 15 min was at least 90% both at baseline (76/84 [90%]) and after implementation (129/142 [91%]) (p = 0.80). Median dispensary turnaround time for stat and emergent medication orders combined (10 versus 9 min, p = 0.27) and for urgent and now medication orders combined (10 versus 12 min, p = 0.09) did not change after implementation of formal definitions. Similarly, median total turnaround time did not change for stat and emergent medication orders combined (30 versus 45 min, p = 0.32), but it increased for urgent and now orders combined (35 versus 45 min, p = 0.041). CONCLUSIONS Implementing standardized definitions for "stat", "emergent", "urgent", and "now" had no significant effect on dispensary turnaround time. However, the majority of orders with these designations met the expected target for dispensary turnaround time. Further interventions aimed at other health care professionals may be needed to reduce total turnaround time. This research supports the concept of interdisciplinary interventions for reducing total turnaround time.
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Affiliation(s)
- Heather Naylor
- , BScPharm, ACPR, is with the Winnipeg Regional Health Authority Pharmacy Program, Seven Oaks General Hospital Site, Winnipeg, Manitoba
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16
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Abstract
Since its discovery two decades ago, the activation of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway by numerous cytokines and growth factors has resulted in it becoming one of the most well-studied intracellular signalling networks. The field has progressed from the identification of the individual components to high-resolution crystal structures of both JAK and STAT, and an understanding of the complexities of the molecular activation and deactivation cycle which results in a diverse, yet highly specific and regulated pattern of transcriptional responses. While there is still more to learn, we now appreciate how disruption and deregulation of this pathway can result in clinical disease and look forward to adoption of the next generation of JAK inhibitors in routine clinical treatment.
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Affiliation(s)
- Hiu Kiu
- Walter & Eliza Hall Institute, 1G Royal Parade, Parkville 3052, Australia
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17
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Matthews JR, Sansom OJ, Clarke AR. Absolute requirement for STAT3 function in small-intestine crypt stem cell survival. Cell Death Differ 2011; 18:1934-43. [PMID: 21637293 PMCID: PMC3214915 DOI: 10.1038/cdd.2011.77] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 04/12/2011] [Accepted: 04/27/2011] [Indexed: 11/09/2022] Open
Abstract
The transcription factor signal transducer and activator of transcription 3 (STAT3) is frequently activated in human cancers. Interestingly, STAT3 also maintains the pluripotency and self-renewal of murine embryonic stem cells, and several tissue stem cell types. To investigate whether STAT3 also maintains the small-intestine crypt stem cell, we conditionally inactivated a Floxed Stat3 allele (Stat3(fl)) in murine small-intestine crypt stem cells. Following Cre recombinase expression, apoptosis increased in Stat3(fl/-) experimental crypts relative to Stat3(wt/-) controls before declining. Control Stat3(wt/-) mice carrying a Flox-STOP LacZ reporter transgene stably expressed LacZ after Cre induction. In contrast, Stat3(fl/-) intestine LacZ expression initially increased modestly, before declining to background levels. Quantitative PCRs revealed a similar transient in recombined Stat3(fl) allele levels. Long-term bromodeoxyuridine labelling directly demonstrated that functional STAT3 is required for +4 to +6 region label-retaining small-intestine stem cell survival. Rapid clearance of recombined Stat3(fl/-) cells involves apoptosis potentially induced by elevated c-Myc in non-recombined cells and involves elevated p53 expression and caspase 3 activation. Intriguingly, Stat3(fl/-) intestine recombination triggered dramatically upregulated polycomb transcriptional repressor Bmi1 - potentially accelerating recombined crypt repopulation. In summary, STAT3 activity is absolutely required for small-intestine crypt stem cell survival at both the +4 to +6 label-retaining and crypt base columnar cell locations.
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Affiliation(s)
- J R Matthews
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University, Cardiff, UK
| | - O J Sansom
- CRUK Beatson Institute for Cancer Research, Bearsden, Glasgow, UK
| | - A R Clarke
- Division of Pathophysiology and Repair, School of Biosciences, Cardiff University, Cardiff, UK
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18
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Mehra R, Serebriiskii IG, Dunbrack RL, Robinson MK, Burtness B, Golemis EA. Protein-intrinsic and signaling network-based sources of resistance to EGFR- and ErbB family-targeted therapies in head and neck cancer. Drug Resist Updat 2011; 14:260-79. [PMID: 21920801 PMCID: PMC3195944 DOI: 10.1016/j.drup.2011.08.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [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: 07/30/2011] [Revised: 08/16/2011] [Accepted: 08/17/2011] [Indexed: 02/07/2023]
Abstract
Agents targeting EGFR and related ErbB family proteins are valuable therapies for the treatment of many cancers. For some tumor types, including squamous cell carcinomas of the head and neck (SCCHN), antibodies targeting EGFR were the first protein-directed agents to show clinical benefit, and remain a standard component of clinical strategies for management of the disease. Nevertheless, many patients display either intrinsic or acquired resistance to these drugs; hence, major research goals are to better understand the underlying causes of resistance, and to develop new therapeutic strategies that boost the impact of EGFR/ErbB inhibitors. In this review, we first summarize current standard use of EGFR inhibitors in the context of SCCHN, and described new agents targeting EGFR currently moving through pre-clinical and clinical development. We then discuss how changes in other transmembrane receptors, including IGF1R, c-Met, and TGF-β, can confer resistance to EGFR-targeted inhibitors, and discuss new agents targeting these proteins. Moving downstream, we discuss critical EGFR-dependent effectors, including PLC-γ; PI3K and PTEN; SHC, GRB2, and RAS and the STAT proteins, as factors in resistance to EGFR-directed inhibitors and as alternative targets of therapeutic inhibition. We summarize alternative sources of resistance among cellular changes that target EGFR itself, through regulation of ligand availability, post-translational modification of EGFR, availability of EGFR partners for hetero-dimerization and control of EGFR intracellular trafficking for recycling versus degradation. Finally, we discuss new strategies to identify effective therapeutic combinations involving EGFR-targeted inhibitors, in the context of new system level data becoming available for analysis of individual tumors.
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Affiliation(s)
- Ranee Mehra
- Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111
- Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Ilya G. Serebriiskii
- Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Roland L. Dunbrack
- Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Matthew K. Robinson
- Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Barbara Burtness
- Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111
- Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Erica A. Golemis
- Program in Developmental Therapeutics, Fox Chase Cancer Center, Philadelphia, PA 19111
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19
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Zhang L, Jilg N, Shao RX, Lin W, Fusco DN, Zhao H, Goto K, Peng LF, Chen WC, Chung RT. IL28B inhibits hepatitis C virus replication through the JAK- STAT pathway. J Hepatol 2011; 55:289-98. [PMID: 21147189 PMCID: PMC3068235 DOI: 10.1016/j.jhep.2010.11.019] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/16/2010] [Accepted: 11/18/2010] [Indexed: 01/09/2023]
Abstract
BACKGROUND & AIMS The combination of pegylated interferon (IFN) α and ribavirin (RBV) is the standard therapy for patients with chronic HCV infection. However, it produces a sustained virologic response (SVR) in only half of the treated individuals and is associated with significant side effects. Recently, several single-nucleotide polymorphisms (SNPs) near the IL28B locus, also known as IFNλ3, were identified to be strong predictors of SVR in patients receiving PEG-IFN and RBV. We sought to determine whether IL28B was capable of inhibiting HCV replication and to determine the pathway by which IL28B exhibits anti-HCV activity. METHODS Using the full-length HCV replicon OR6 and the infectious HCV clones JFH1 and Jc1, we assessed the anti-HCV effect of IL28B on HCV and characterized the key steps of the JAK-STAT pathway by real time PCR, luciferase assay, and Western blot. Finally, we evaluated the anti-HCV effect of IL28B in the presence of JAK-STAT pathway inhibitors such as blocking antibodies, a pharmacological inhibitor, and siRNAs. RESULTS We found that IL28B inhibits HCV replication in a dose- and time-dependent manner. Like IFNα, IL28B induces the phosphorylation of STAT1 and STAT2, ISRE-driven transcription, and expression of known ISGs. The anti-HCV effects of IL28A, IL28B, and IL29 were abrogated by an IL10R2 blocking antibody, a pharmacological inhibitor of JAK1/TYK2, and by siRNA against IL28R1, STAT1, STAT2, and IRF9. CONCLUSIONS Our data demonstrate that IL28A, IL28B, and IL29 signal through the JAK-STAT pathway to inhibit HCV. These data suggest possible applications of new approaches in HCV treatment.
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Affiliation(s)
- Leiliang Zhang
- Co-corresponding authors: Raymond T. Chung, M.D., GI Unit, Warren 1007, Massachusetts General Hospital, Boston, MA 02114, Phone: (617) 724-7562, Fax: (617) 643-0446, , Leiliang Zhang, GI Unit, Warren 1007, Massachusetts General Hospital, Boston, MA 02114,
| | | | - Run-Xuan Shao
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Wenyu Lin
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Dahlene N. Fusco
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Hong Zhao
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Kaku Goto
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Lee F. Peng
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Wen-Chi Chen
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Raymond T. Chung
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
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20
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Boengler K, Hilfiker-Kleiner D, Heusch G, Schulz R. Inhibition of permeability transition pore opening by mitochondrial STAT3 and its role in myocardial ischemia/reperfusion. Basic Res Cardiol 2010; 105:771-85. [PMID: 20960209 PMCID: PMC2978889 DOI: 10.1007/s00395-010-0124-1] [Citation(s) in RCA: 307] [Impact Index Per Article: 21.9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 09/27/2010] [Accepted: 10/01/2010] [Indexed: 01/17/2023]
Abstract
The signal transducer and activator of transcription 3 (STAT3) contributes to cardioprotection by ischemic pre- and postconditioning. Mitochondria are central elements of cardioprotective signaling, most likely by delaying mitochondrial permeability transition pore (MPTP) opening, and STAT3 has recently been identified in mitochondria. We now characterized the mitochondrial localization of STAT3 and its impact on respiration and MPTP opening. STAT3 was mainly present in the matrix of subsarcolemmal and interfibrillar cardiomyocyte mitochondria. STAT1, but not STAT5 was also detected in mitochondria under physiological conditions. ADP-stimulated respiration was reduced in mitochondria from mice with a cardiomyocyte-specific deletion of STAT3 (STAT3-KO) versus wildtypes and in rat mitochondria treated with the STAT3 inhibitor Stattic (STAT3 inhibitory compound, 6-Nitrobenzo[b]thiophene 1,1-dioxide). Mitochondria from STAT3-KO mice and Stattic-treated rat mitochondria tolerated less calcium until MPTP opening occurred. STAT3 co-immunoprecipitated with cyclophilin D, the target of the cardioprotective agent and MPTP inhibitor cyclosporine A (CsA). However, CsA reduced infarct size to a similar extent in wildtype and STAT3-KO mice in vivo. Thus, STAT3 possibly contributes to cardioprotection by stimulation of respiration and inhibition of MPTP opening.
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Affiliation(s)
- Kerstin Boengler
- Institut für Pathophysiologie, Zentrum für Innere Medizin, Universitätsklinikum Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Denise Hilfiker-Kleiner
- Molekulare Kardiologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Gerd Heusch
- Institut für Pathophysiologie, Zentrum für Innere Medizin, Universitätsklinikum Essen, Hufelandstr. 55, 45122 Essen, Germany
| | - Rainer Schulz
- Institut für Pathophysiologie, Zentrum für Innere Medizin, Universitätsklinikum Essen, Hufelandstr. 55, 45122 Essen, Germany
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21
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Nillni EA. Regulation of the hypothalamic thyrotropin releasing hormone (TRH) neuron by neuronal and peripheral inputs. Front Neuroendocrinol 2010; 31:134-56. [PMID: 20074584 DOI: 10.1016/j.yfrne.2010.01.001] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 12/29/2009] [Accepted: 01/06/2010] [Indexed: 12/29/2022]
Abstract
The hypothalamic-pituitary-thyroid (HPT) axis plays a critical role in mediating changes in metabolism and thermogenesis. Thus, the central regulation of the thyroid axis by Thyrotropin Releasing Hormone (TRH) neurons in the paraventricular nucleus of the hypothalamus (PVN) is of key importance for the normal function of the axis under different physiological conditions including cold stress and changes in nutritional status. Before the TRH peptide becomes biologically active, a series of tightly regulated processes occur including the proper folding of the prohormone for targeting to the secretory pathway, its post-translational processing, and targeting of the processed peptides to the secretory granules near the plasma membrane of the cell ready for secretion. Multiple inputs coming from the periphery or from neurons present in different areas of the brain including the hypothalamus are responsible for the activation or inhibition of the TRH neuron and in turn affect the output of TRH and the set point of the axis.
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22
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Abstract
Since the somatomedin hypothesis of growth hormone (GH) action was first formulated more than 50 years ago, the key roles of both GH and insulin-like growth factor-I (IGF-I) in human growth have been extended to include important effects on tissue maintenance and repair. More recent observations have revealed that this pathway has a negative side, as it has been implicated as a potential contributor to the development of several human cancers and has been linked to diminished lifespan in experimental animals. This brief review focuses on fundamental aspects of gene regulation by GH, as long-term hormonal effects all require changes in gene expression. Topics to be discussed include GH-stimulated signal transduction pathways, mechanisms of gene activation and gene repression by GH, and an analysis of control of IGF-I gene transcription by the GH-stimulated transcription factor, signal transducer and activator of transcription (Stat)5b.
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Affiliation(s)
- Peter Rotwein
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239-3098, USA.
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23
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Abstract
Suppressor of cytokine signalling (SOCS) 3 is an essential regulator of cytokine signalling, and in turn its expression is tightly regulated. Data from overexpression studies in cell lines suggest that SOCS2 regulates SOCS3 protein degradation, by forming a molecular bridge to an E3 ubiquitin-ligase complex. Whether this regulation is relevant in primary cells is unknown. In this study, we utilized Socs2( - / - ) mice to examine the role of SOCS2 in modulating SOCS3 expression and degradation, and its impact on interleukin-2 (IL-2) and IL-6 signalling in primary haemopoietic cells. Both biochemical and biological analyses demonstrated unperturbed SOCS3 expression and cytokine signalling in the absence of SOCS2. Our results suggest that SOCS2 is not a physiological regulator of SOCS3 expression and action in primary haemopoietic cells.
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Affiliation(s)
- Hiu Kiu
- Division of Cancer and Haematology, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia
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24
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Ichikawa T, Li J, Nagarkatti P, Nagarkatti M, Hofseth LJ, Windust A, Cui T. American ginseng preferentially suppresses STAT/iNOS signaling in activated macrophages. J Ethnopharmacol 2009; 125:145-50. [PMID: 19505555 PMCID: PMC2790430 DOI: 10.1016/j.jep.2009.05.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Revised: 04/21/2009] [Accepted: 05/28/2009] [Indexed: 05/23/2023]
Abstract
AIM OF THE STUDY Ginseng has been used as general tonic for thousands of years in Asia and becomes a popular herbal medicine all over the world. However, the cellular and molecular mechanisms underlying its benefit effects are less explored. Thus, we investigated the effect of a crude extract from Panax quinquefolius (American ginseng) on suppression of pro-inflammatory responses in macrophages with a focus on signal transducer and activator of transcription (STAT) signaling. MATERIALS AND METHODS The crude extract of American ginseng that was supplied by the National Research Council of Canada, Institute for National Measurement Standards (NRCC-INMS) was freshly solvated in Dulbecco's Modified Eagle Medium (DMEM) prior to each experiment. RAW264.7 cells, a murine macrophage cell line, were exposed to lipopolysaccharide (LPS) to induce inflammatory responses such as expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). Proteins were measured by Western blot and mRNA expression was determined by quantitative real-time PCR (Q-PCR). Activator protein 1 (AP-1)-, nuclear factor-kappaB (NF-kappaB)- and STAT-mediated transcriptional activities were investigated using luciferase reporter constructs. RESULTS American ginseng inhibited LPS-induced iNOS expression; however, it did not affect LPS-induced COX2 expression. While American ginseng had no impact on LPS-induced activation of AP-1 or NF-kappaB pathways, it dramatically inhibited LPS-induced activation of STAT signaling. Moreover, American ginseng and AG490, an inhibitor of STAT cascade, synergistically suppressed the LPS-induced iNOS expression. CONCLUSION American ginseng selectively inhibits the expression of iNOS via suppression of STAT cascade but not NF-kappaB and AP-1 pathways in inflamed macrophages. Such a preferential suppression of STAT/iNOS cascade by American ginseng might have therapeutic potential for inflammatory diseases with over-activation of iNOS.
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Affiliation(s)
- Tomonaga Ichikawa
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC, 29208
| | - Jinqing Li
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC, 29208
| | - Prakash Nagarkatti
- Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC, 29208
| | - Mitzi Nagarkatti
- Department of Pathology, Microbiology and Immunology, University of South Carolina, Columbia, SC, 29208
| | - Lorne J. Hofseth
- Department of Pharmaceutical and Biomedical Sciences, University of South Carolina, Columbia, SC, 29208
| | | | - Taixing Cui
- Department of Cell Biology and Anatomy, University of South Carolina, Columbia, SC, 29208
- Corresponding author: Taixing Cui, MD, PhD, Tel: +1-803-253-5837; Fax: +1-803-733-3153;
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25
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Li W, Ferguson BJ, Khaled WT, Tevendale M, Stingl J, Poli V, Rich T, Salomoni P, Watson CJ. PML depletion disrupts normal mammary gland development and skews the composition of the mammary luminal cell progenitor pool. Proc Natl Acad Sci U S A 2009; 106:4725-30. [PMID: 19261859 PMCID: PMC2660741 DOI: 10.1073/pnas.0807640106] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [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: 08/08/2008] [Indexed: 01/08/2023] Open
Abstract
Nuclear domains of promyelocytic leukemia protein (PML) are known to act as signaling nodes in many cellular processes. Although the impact of PML expression in driving cell fate decisions for injured cells is well established, the function of PML in the context of tissue development is less well understood. Here, the in vivo role of PML in developmental processes in the murine mammary gland has been investigated. Data are presented showing that expression of PML is tightly regulated by three members of the Stat family of transcription factors that orchestrate the functional development of the mammary secretory epithelium during pregnancy. Developmental phenotypes were also discovered in the virgin and pregnant Pml null mouse, typified by aberrant differentiation of mammary epithelia with reduced ductal and alveolar development. PML depletion was also found to disturb the balance of two distinct luminal progenitor populations. Overall, it is shown that PML is required for cell lineage determination in bi-potent luminal progenitor cells and that the precise regulation of PML expression is required for functional differentiation of alveolar cells.
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Affiliation(s)
- Wenjing Li
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom
| | - Brian J. Ferguson
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom
| | - Walid T. Khaled
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom
| | - Maxine Tevendale
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom
| | - John Stingl
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom
| | - Valeria Poli
- Molecular Biotechnology Center, University of Turin, Via Nizza 52, 10126 Turin, Italy
| | - Tina Rich
- Faculty of Veterinary Medicine, Institute of Comparative Medicine, 464 Bearsden Road, Glasgow G61 1QH, United Kingdom; and
| | - Paolo Salomoni
- MRC Toxicology Unit, Lancaster Road, P.O. Box 138, Leicester LE1 9HN, United Kingdom
| | - Christine J. Watson
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, United Kingdom
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Abstract
The role of natural killer (NK) cells in controlling hepatitis C virus (HCV) infection and replication has not been fully delineated. We examined NK cell-mediated noncytolytic effect on full cycle HCV infection of human hepatocytes. Human hepatocytes (Huh7.5.1 cells) co-cultured with NK cells or treated with supernatants (SN) from NK cells cultures had significantly lower levels of HCV RNA and protein than control cells. This NK cell-mediated anti-HCV activity could be largely abolished by antibody to interferon-gamma (IFN-gamma). The investigation of the mechanisms for NK cell-mediated anti-HCV activity showed that NK SN-treated hepatocytes expressed higher levels of IFN-alpha/beta than the control cells. NK SN also enhanced IFN regulatory factor-3 and 7 expression in the hepatocytes. In addition, NK SN enhanced the expression of signal transducer and activator of transcription 1 and 2, the nuclear factors that are essential for the activation of IFN-mediated antiviral pathways. These data provide direct evidence at cellular and molecular levels that NK cells have a key role in suppressing HCV infection of and replication in human hepatocytes.
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Affiliation(s)
- S.-H. Wang
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA,Renmin Hospital of Wuhan University, Wuhan University, Hubei, China
| | - C.-X. Huang
- Renmin Hospital of Wuhan University, Wuhan University, Hubei, China
| | - L. Ye
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - X. Wang
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - L. Song
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Y.-J. Wang
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - H. Liang
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - X.-Y. Huang
- Renmin Hospital of Wuhan University, Wuhan University, Hubei, China
| | - W.-Z. Ho
- Division of Allergy and Immunology, Joseph Stokes, Jr. Research Institute at The Children’s Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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27
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Kimura A, Naka T, Kishimoto T. IL-6-dependent and -independent pathways in the development of interleukin 17-producing T helper cells. Proc Natl Acad Sci U S A 2007; 104:12099-104. [PMID: 17623780 PMCID: PMC1924582 DOI: 10.1073/pnas.0705268104] [Citation(s) in RCA: 258] [Impact Index Per Article: 15.2] [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: 05/19/2007] [Indexed: 12/13/2022] Open
Abstract
CD4(+) T cells producing IL-17 [T helper (Th)17], as distinct from Th1 or Th2 cells, have recently been shown to be associated with autoimmunity, but it is not entirely clear how Th17 cells are generated from naïve T cells. We demonstrate here that IL-6, but not TNF-alpha or IL-1beta, can, in combination with TGF-beta, induce Th17 cell generation from naïve T cells and inhibit TGF-beta-induced Foxp3 expression. Moreover, conditioned medium from lipopolysaccharide-stimulated bone marrow-derived dendritic cells (DCCM) can induce IL-17 production in naïve T cells. Interestingly, IL-17 was produced by DCCM even with the addition of anti-gp130 antibody or DCCM from IL-6 KO mice. The combination of IL-6 and TGF-beta could maintain activation of signal transducer and activator of transcription (Stat)3, but not of Stat1. IL-27 or IFN-gamma suppressed the induction of Th17 cells by TGF-beta plus IL-6 and maintained Stat1 activation under these conditions. In contrast, both Stat1 and Stat3 remained to be activated in naïve T cells cultured with DCCM. These findings represent a different basis for Th17 differentiation from naïve T cells.
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MESH Headings
- Animals
- Cell Differentiation/drug effects
- Cell Lineage/drug effects
- Dendritic Cells/cytology
- Dendritic Cells/drug effects
- Female
- Gene Expression Regulation/drug effects
- Humans
- Interferon-gamma/pharmacology
- Interleukin-17/biosynthesis
- Interleukin-1beta/pharmacology
- Interleukin-6/pharmacology
- Mice
- Mice, Inbred C57BL
- Nuclear Receptor Subfamily 1, Group F, Member 3
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism
- Receptors, Thyroid Hormone/genetics
- Receptors, Thyroid Hormone/metabolism
- STAT1 Transcription Factor/metabolism
- STAT3 Transcription Factor/metabolism
- T-Lymphocytes, Helper-Inducer/cytology
- T-Lymphocytes, Helper-Inducer/drug effects
- Transforming Growth Factor beta/pharmacology
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Akihiro Kimura
- *Laboratory of Immune Regulation, Osaka University Graduate School of Frontier Biosciences, 1-3, Yamada-oka, Suita, Osaka, 565-0871, Japan; and
| | - Tetsuji Naka
- Laboratory for Immune Signal, National Institute of Biomedical Innovation, 7-6-8, Saito Asagi, Ibaraki City, Osaka, 567-0085, Japan
| | - Tadamitsu Kishimoto
- *Laboratory of Immune Regulation, Osaka University Graduate School of Frontier Biosciences, 1-3, Yamada-oka, Suita, Osaka, 565-0871, Japan; and
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28
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Abstract
A variety of cytokines and growth factors use the Janus kinase (Jak)-STAT signaling pathway to transmit extracellular signals to the nucleus. STATs (signal transducers and activators of transcription) are latent cytoplasmic transcription factors. There are seven mammalian STATs and they have critical, nonredundant roles in mediating cellular transcriptional responses to cytokines. The physiological roles of STATs have been elucidated by analysis of mice rendered deficient in STAT genes. STAT activation is regulated and can be modulated in a positive or negative fashion; it can be reprogrammed to drive different cellular responses. Several auto-regulatory and signaling crosstalk mechanisms for regulating Jak-STAT signaling have been described. Understanding and manipulation of the function of STATs will help in the development of therapeutic strategies for diseases that are regulated by cytokines.
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Affiliation(s)
- Lionel B Ivashkiv
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, Graduate Program in Immunology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York, USA
| | - Xiaoyu Hu
- Arthritis and Tissue Degeneration Program, Hospital for Special Surgery, Graduate Program in Immunology, Weill Graduate School of Medical Sciences of Cornell University, New York, New York, USA
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29
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Li WX. Receptor tyrosine kinase signaling and primordial germ cell development. Cell Cycle 2004; 3:249-51. [PMID: 14726648 PMCID: PMC3090257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023] Open
Abstract
Primordial germ cells (PGCs) give rise to sperms and eggs. Their development is crucial to species propagation and has to be precisely controlled. Studies in several model organisms have identified many genes involved in the specification and guided migration of PGCs. However, the mechanisms governing the behaviors of these unique cells remain to be investigated. Interestingly, PGCs share certain cellular properties with metastasizing cancer cells including proliferation, invasion of other tissues, survival and migration. Recently we have shown that in Drosophila the receptor tyrosine kinase Torso activates both STAT and Ras during the early phase of PGC development. In later stages, activation of both STAT and Ras, likely by other molecules, is required continuously for PGC migration. The requirement for RTK suggests molecular conservation between flies and mice in PGC development and also suggests that germ cells and cancer cells share certain intracellular signaling strategies.
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Affiliation(s)
- Willis X Li
- Department of Biomedical Genetics, University of Rochester Medical Center, 601 Elmwood Ave., Box 633, Rochester, New York 14642, USA.
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30
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Kryworuchko M, Pasquier V, Thèze J. Human immunodeficiency virus-1 envelope glycoproteins and anti-CD4 antibodies inhibit interleukin-2-induced Jak/ STAT signalling in human CD4 T lymphocytes. Clin Exp Immunol 2003; 131:422-7. [PMID: 12605694 PMCID: PMC1808643 DOI: 10.1046/j.1365-2249.2003.02065.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [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] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus (HIV) infection leads to a profound T cell dysfunction well before the clinical onset of acquired immunodeficiency syndrome (AIDS). We have been accumulating evidence that one of the mechanisms responsible for this T cell deficiency may be the dysregulation of signal transduction via the interleukin (IL)-2/IL-2 receptor (R) complex. In CD4 T cells, we have observed previously that viral envelope (env) glycoproteins induce IL-2 unresponsiveness and the down-regulation of the three chains making up the IL-2R (alpha, beta, gamma) in vitro. We have now established further that this disruption of the IL-2/IL-2R system manifests itself in defective signal propagation via the Janus kinase (Jak)/signal transducer and activator of transcription (STAT) pathway in response to IL-2. The treatment of CD4 T cells with HIV env or surface ligation of CD4 with anti-CD4 monoclonal antibodies inhibited the IL-2-induced activation of Jak-1 and Jak-3, as well as their targets, STAT5a and STAT5b. This Jak/STAT deficiency may contribute to the crippling of CD4 T cell responses to a cytokine central to the immune response by HIV.
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Affiliation(s)
- M Kryworuchko
- Unité d'Immunogénétique Cellulaire, Département de Medecine Moleculaire, Institut Pasteur, Paris, France
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31
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Abstract
ISG15 is one of the most strongly induced genes upon viral infection, type I interferon (IFN) stimulation, and lipopolysaccharide (LPS) stimulation. Here we report that mice lacking UBP43, a protease that removes ISG15 from ISGylated proteins, are hypersensitive to type I IFN. Most importantly, in UBP43-deficient cells, IFN-beta induces a prolonged Stat1 tyrosine phosphorylation, DNA binding, and IFN-mediated gene activation. Furthermore, restoration of ISG15 conjugation in protein ISGylation-defective K562 cells increases IFN-stimulated promoter activity. These findings identify UBP43 as a novel negative regulator of IFN signaling and suggest the involvement of protein ISGylation in the regulation of the JAK-STAT pathway.
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Affiliation(s)
- Oxana A Malakhova
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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32
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Chen X, Bhandari R, Vinkemeier U, Van Den Akker F, Darnell JE, Kuriyan J. A reinterpretation of the dimerization interface of the N-terminal domains of STATs. Protein Sci 2003; 12:361-5. [PMID: 12538899 PMCID: PMC2312425 DOI: 10.1110/ps.0218903] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [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] [Indexed: 10/27/2022]
Abstract
The crystal structures of the N-terminal domain (N-domain) and the core region of the STAT family of transcription factors have been determined previously. STATs can form cooperative higher order structures (tetramers or higher oligomers) while bound to DNA. The crystal packing in the STAT4 N-domain crystal structure, determined at 1.5 A resolution, suggests two alternate organizations of the N-domain dimer. We now present the results of site directed mutagenesis of residues predicted to be involved at each dimer interface. Our results indicate that the dimer interface suggested earlier as being physiologically relevant is, in fact, unlikely to be so. Given the alternative model for the N-domain dimer, the ability of the N-domain to mediate interactions of two STAT dimers on DNA remains unchanged.
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Affiliation(s)
- Xiaomin Chen
- Department of Biochemistry and Molecular Biology, The University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA
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33
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Chen CW, Chao Y, Chang YH, Hsu MJ, Lin WW. Inhibition of cytokine-induced JAK- STAT signalling pathways by an endonuclease inhibitor aurintricarboxylic acid. Br J Pharmacol 2002; 137:1011-20. [PMID: 12429573 PMCID: PMC1573578 DOI: 10.1038/sj.bjp.0704955] [Citation(s) in RCA: 31] [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] [Indexed: 11/09/2022] Open
Abstract
1. Inducible nitric oxide (iNOS) is thought to involve in host defence and tissue damage in inflammatory loci. In previous study, we have found that the endonuclease inhibitor aurintricarboxylic acid (ATA) can protect macrophages from cell death induced by bacterial lipopolysaccharide. This action is through the interruption with signalling pathways for NF-kappa B and AP-1 activation, and thus iNOS expression. In this study we have addressed the effects of ATA on JAK-STAT signalling pathways. 2. In murine RAW 264.7 macrophages, IFN-gamma-mediated NO production and iNOS expression were concentration-dependently reduced by the presence of 3-100 micro M ATA. 3. IFN-gamma-induced STAT1 activation, as assessed from its tyrosine phosphorylation, nuclear translocation, binding to specific DNA response element and evoked IRF-1 reporter gene assay, were concomitantly inhibited by ATA. However, ATA did not alter IFN-gamma binding to RAW 264.7 cells. 4. The activities of JAK1 and JAK2, the upstream kinases essential for STAT1 signalling in response to IFN-gamma, were also reduced by ATA. 5. Moreover, IL-4, IL-10, GM-CSF and M-CSF elicited tyrosine phosphorylation of STAT3, STAT5 and/or STAT6 in macrophages were diminished by the presence of ATA. 6. Taken together, we conclude that ATA can interfere JAK-STAT signalling pathways in response to cytokines. This action contributes to the inhibition of IFN-gamma-induced iNOS expression.
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Affiliation(s)
- Ching-Wen Chen
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yee Chao
- Cancer Center, Veterans General Hospital, Taipei, Taiwan
| | - Ying-Hsin Chang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Jen Hsu
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wan-Wan Lin
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Author for correspondence:
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34
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Song L, Li Y, Shen B. Protein kinase ERK contributes to differential responsiveness of human myeloma cell lines to IFNalpha. Cancer Cell Int 2002; 2:9. [PMID: 12234375 PMCID: PMC140137 DOI: 10.1186/1475-2867-2-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2002] [Accepted: 07/08/2002] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND: Despite IFNalpha has been used extensively in the treatment of multiple myeloma (MM), there are also several reports suggesting that IFNalpha may aggravate isease in some MM patients. That means the effect of IFNalpha on the growth of myeloma cells in vivo may be different. In this study, we selected two human myeloma cell lines that vary remarkably in response to IFNalpha and focused on elucidating the mechanism of differential IFNalpha responsiveness. RESULTS: Sko-007 is a myeloma cell line whose growth is arrested by IFNalpha; however, IFNalpha promoted the proliferation of the other myeloma cell line U266. We observed that the growth-stimulation effect of IFNalpha on U266 cells did not result from up-regulation of the IL-6 receptors on cell surface; while IFNalpha treatment on Sko-007 cells significantly reduced gp130 expression. Moreover, the transcription factors STAT3 and STAT1, which are involved in the JAK/STAT signal transduction pathway, can be activated in both IFNalpha-stimulated and -inhibited myeloma cell lines; while the activation of the protein kinase ERK, which is involved in the Ras/MAPK signal transduction pathway, can be down-regulated in IFNalpha-arrested Sko-007 cells and up-regulated in IFNalpha-stimulated U266 cells. In addition, both IFNalpha-induced growth-stimulation effect and the up-regulated activation of ERK in U266 cells were efficiently inhibited by PD98059, the specific inhibitor of MAPK/ERK kinase (MEK). CONCLUSION: Myeloma cells responsiveness to IFNalpha is heterogeneous and the activation state of ERK in the Ras/MAPK signalling pathway mainly contributed to this difference.
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Affiliation(s)
- Lun Song
- Department of Molecular Immunology, Institute of Basic Medical Sciences, Taiping Road, 27, Beijing, 100850, P. R. China
| | - Yan Li
- Department of Molecular Immunology, Institute of Basic Medical Sciences, Taiping Road, 27, Beijing, 100850, P. R. China
| | - Beifen Shen
- Department of Molecular Immunology, Institute of Basic Medical Sciences, Taiping Road, 27, Beijing, 100850, P. R. China
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35
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Smeltz RB, Chen J, Hu-Li J, Shevach EM. Regulation of interleukin (IL)-18 receptor alpha chain expression on CD4(+) T cells during T helper (Th)1/Th2 differentiation. Critical downregulatory role of IL-4. J Exp Med 2001; 194:143-53. [PMID: 11457889 PMCID: PMC2193456 DOI: 10.1084/jem.194.2.143] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [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] [Indexed: 11/04/2022] Open
Abstract
Interleukin (IL)-18 has been well characterized as a costimulatory factor for the induction of IL-12-mediated interferon (IFN)-gamma production by T helper (Th)1 cells, but also can induce IL-4 production and thus facilitate the differentiation of Th2 cells. To determine the mechanisms by which IL-18 might regulate these diametrically distinct immune responses, we have analyzed the role of cytokines in the regulation of IL-18 receptor alpha chain (IL-18Ralpha) expression. The majority of peripheral CD4(+) T cells constitutively expressed the IL-18Ralpha. Upon antigen stimulation in the presence of IL-12, marked enhancement of IL-18Ralpha expression was observed. IL-12-mediated upregulation of IL-18Ralpha required IFN-gamma. Activated CD4(+) T cells that expressed low levels of IL-18Ralpha could produce IFN-gamma when stimulated with the combination of IL-12 and IL-18, while CD4(+) cells which expressed high levels of IL-18Ralpha could respond to IL-18 alone. In contrast, T cell stimulation in the presence of IL-4 resulted in a downregulation of IL-18Ralpha expression. Both IL-4(-/)- and signal transducer and activator of transcription (Stat)6(-/)- T cells expressed higher levels of IL-18Ralpha after TCR stimulation. Furthermore, activated T cells from Stat6(-/)- mice produced more IFN-gamma in response to IL-18 than wild-type controls. Thus, positive/negative regulation of the IL-18Ralpha by the major inductive cytokines (IL-12 and IL-4) determines the capacity of IL-18 to polarize an immune response.
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Affiliation(s)
- Ronald B. Smeltz
- Laboratory of Immunology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - June Chen
- Laboratory of Immunology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
- Howard Hughes Medical Institute, National Institutes of Health Research Scholars Program, Bethesda, MD 20814
| | - Jane Hu-Li
- Laboratory of Immunology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Ethan M. Shevach
- Laboratory of Immunology, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
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36
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Ernst M, Inglese M, Waring P, Campbell IK, Bao S, Clay FJ, Alexander WS, Wicks IP, Tarlinton DM, Novak U, Heath JK, Dunn AR. Defective gp130-mediated signal transducer and activator of transcription ( STAT) signaling results in degenerative joint disease, gastrointestinal ulceration, and failure of uterine implantation. J Exp Med 2001; 194:189-203. [PMID: 11457894 PMCID: PMC2193459 DOI: 10.1084/jem.194.2.189] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.3] [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] [Indexed: 01/20/2023] Open
Abstract
The receptor subunit gp130 transduces multiple cell type-specific activities of the leukemia inhibitory factor (LIF)/interleukin (IL)-6 family of cytokines through the signal transducer and activator of transcription (STAT) and src homology 2 domain-bearing protein tyrosine phosphatase (SHP)-2/ras/Erk pathways. To define STAT-dependent physiological responses, we generated mice with a COOH-terminal gp130(DeltaSTAT) "knock-in" mutation which deleted all STAT-binding sites. gp130(DeltaSTAT) mice phenocopyed mice deficient for IL-6 (impaired humoral and mucosal immune and hepatic acute phase responses) and LIF (failure of blastocyst implantation). However, unlike mice with null mutations in any of the components in the gp130 signaling pathway, gp130(DeltaSTAT) mice also displayed gastrointestinal ulceration and a severe joint disease with features of chronic synovitis, cartilaginous metaplasia, and degradation of the articular cartilage. Mitogenic hyperresponsiveness of synovial cells to the LIF/IL-6 family of cyto-kines was caused by sustained gp130-mediated SHP-2/ras/Erk activation due to impaired STAT-mediated induction of suppressor of cytokine signaling (SOCS) proteins which normally limits gp130 signaling. Therefore, the joint pathology in gp130(DeltaSTAT) mice is likely to arise from the disturbance of the otherwise balanced activation of the SHP-2/ras/Erk and STAT signaling cascades emanating from gp130.
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Affiliation(s)
- M Ernst
- Ludwig Institute for Cancer Research, PO Royal Melbourne Hospital, VIC 3050, Australia.
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37
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Mizuguchi R, Noto S, Yamada M, Ashizawa S, Higashi H, Hatakeyama M. Ras and signal transducer and activator of transcription ( STAT) are essential and sufficient downstream components of Janus kinases in cell proliferation. Jpn J Cancer Res 2000; 91:527-33. [PMID: 10835498 PMCID: PMC5926385 DOI: 10.1111/j.1349-7006.2000.tb00977.x] [Citation(s) in RCA: 13] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Cytokines exert their activities in cell growth and differentiation by binding specific cell membrane receptors. Janus kinases (JAKs) are cytoplasmic protein tyrosine kinases that physically interact with intracellular domains of the cytokine receptors and they play crucial roles in transducing signals triggered by the cytokine-receptor interaction. We have previously shown that conditional activation of JAK through membrane-proximal dimerization confers cytokine-independence on interleukin-3 (IL-3)-dependent Ba / F3 lymphoid cells and that the cytokine-independent proliferation is completely inhibited by dominant negative Ras. In this work, we demonstrate that ectopic expression of a dominant negative form of Stat5, a major signal transducer and activator of transcription (STAT) expressed in Ba / F3 cells, also inhibits JAK-triggered mitogenesis. In contrast, overexpression of constitutively active Ras or conditional activation of Stat5 by chemical dimerization fails to confer cytokine-independence. However, concomitant activation of ectopic Ras and Stat5 molecules in Ba / F3 cells suffices for cell proliferation in the absence of IL-3. Our results indicate that Ras and STAT are essential and sufficient components of JAK-triggered mitogenesis. Our findings further indicate that the cytokine signal bifurcates into Ras and STAT pathways following JAK activation.
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Affiliation(s)
- R Mizuguchi
- Department of Viral Oncology, Cancer Institute, Japanese Foundation for Cancer Research, 1-37-1 Kami-Ikebukuro, Toshima-ku, Tokyo 170-8455, Japan
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38
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Ortmann RA, Cheng T, Visconti R, Frucht DM, O'Shea JJ. Janus kinases and signal transducers and activators of transcription: their roles in cytokine signaling, development and immunoregulation. Arthritis Res 2000; 2:16-32. [PMID: 11094415 PMCID: PMC129988 DOI: 10.1186/ar66] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/14/2023]
Abstract
Cytokines play a critical role in the normal development and function of the immune system. On the other hand, many rheumatologic diseases are characterized by poorly controlled responses to or dysregulated production of these mediators. Over the past decade tremendous strides have been made in clarifying how cytokines transmit signals via pathways using the Janus kinase (Jak) protein tyrosine kinases and the Signal transducer and activator of transcription (Stat) proteins. More recently, research has focused on several distinct proteins responsible for inhibiting these pathways. It is hoped that further elucidation of cytokine signaling through these pathways will not only allow for a better comprehension of the etiopathogenesis of rheumatologic illnesses, but may also direct future treatment options.
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Affiliation(s)
- R A Ortmann
- Lymphocyte Cell Biology Section, Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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39
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Wang X, Halvorsen SW. Reciprocal regulation of ciliary neurotrophic factor receptors and acetylcholine receptors during synaptogenesis in embryonic chick atria. J Neurosci 1998; 18:7372-80. [PMID: 9736657 PMCID: PMC6793252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Ciliary neurotrophic factor (CNTF) has been implicated in the development, survival, and maintenance of a broad range of neurons and glia in the peripheral nervous system and the CNS. Evidence also suggests that CNTF may affect development of cells outside the nervous system. We have found that functional CNTF and its receptor are expressed in developing embryonic chick heart and may be involved in parasympathetic synapse formation. CNTF and CNTF receptor mRNA levels were highest at embryonic day 11 (E11)-E13, the period of parasympathetic innervation in chick atria. Levels of atrial CNTF receptor mRNA were fourfold greater at E13 than at E6 and at E13 were 2.5-fold higher in atria than in ventricle, corresponding to the higher degree of parasympathetic innervation occurring in atria. Treatment of isolated atria or cultured atrial myocytes with recombinant human or avian CNTF resulted in the tyrosine phosphorylation and nuclear translocation of the signal transducer and activator of transcription STAT3. The developmental increase in atrial CNTF receptor mRNA was enhanced by stimulating muscarinic receptors with carbachol in ovo and was inhibited by blocking muscarinic cholinergic receptors with atropine. Treatment of cultured atrial myocytes with CNTF resulted in a twofold increase in the levels of muscarinic receptors. Thus, CNTF was able to regulate a key component of parasympathetic synapses on atrial myocytes. These results suggest a postsynaptic role for CNTF in the onset of parasympathetic function in the developing heart and provide new clues to molecular mechanisms directing synapse formation at targets of the autonomic nervous system.
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MESH Headings
- Animals
- Cells, Cultured
- Chick Embryo
- Cholinergic Fibers/chemistry
- Cholinergic Fibers/physiology
- Heart/embryology
- Heart/innervation
- Heart Atria/cytology
- Heart Atria/embryology
- Heart Atria/innervation
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/metabolism
- Myocardium/chemistry
- Myocardium/cytology
- Neuroprotective Agents/analysis
- Neuroprotective Agents/metabolism
- Parasympathetic Nervous System/chemistry
- Parasympathetic Nervous System/cytology
- Parasympathetic Nervous System/embryology
- RNA, Messenger/analysis
- Receptor Protein-Tyrosine Kinases/analysis
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor Protein-Tyrosine Kinases/metabolism
- Receptor, Ciliary Neurotrophic Factor
- Receptors, Muscarinic/analysis
- Receptors, Muscarinic/metabolism
- Receptors, Nerve Growth Factor/analysis
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/metabolism
- Synapses/chemistry
- Synapses/metabolism
- Up-Regulation/physiology
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Affiliation(s)
- X Wang
- Department of Biochemical Pharmacology, School of Pharmacy, State University of New York at Buffalo, Buffalo, New York 14260-1200, USA
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40
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Kaneko S, Suzuki N, Koizumi H, Yamamoto S, Sakane T. Rescue by cytokines of apoptotic cell death induced by IL-2 deprivation of human antigen-specific T cell clones. Clin Exp Immunol 1997; 109:185-93. [PMID: 9218843 PMCID: PMC1904713 DOI: 10.1046/j.1365-2249.1997.4191324.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [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] [Indexed: 02/04/2023] Open
Abstract
The control of cell survival and cell death is of central importance in tissues with high cell turnover such as the lymphoid system. We have examined the effect of cytokines on IL-2 deprivation-induced apoptosis of human antigen-specific T helper clones with different cytokine production profiles. We found that IL-2, interferon-alpha (IFN-alpha), and IFN-beta inhibited IL-2 deprivation apoptosis in Th0, Th1, and Th2 clones. We also found that IL-2 protects T cell clones from IL-2 deprivation apoptosis accompanying active proliferation and enhanced expression of P53, Rb and Bcl-xL proteins. In contrast, IFN-alpha/beta rescued T cell clones from apoptosis without active proliferation, and expression of apoptosis-associated proteins tested so far was unaffected. This may be due to the fact that T cells treated with IL-2 contained those located in S + G2/M phases of the cell cycle, whereas the vast majority of T cells treated with IFN-alpha/beta were located in G0/G1 phase. IFN-alpha/beta specifically induced tyrosine phosphorylation and translocation into nucleus of signal transducers and activators of transcription (STAT) 2 protein in the T cell clones. In addition, over-expression of STAT2 by transfection of the cDNA prevented apoptosis of the T cell clones. Our present study shows that IFN-alpha and -beta mediate anti-apoptotic effect through other pathways than that of IL-2 in growth factor deprivation apoptosis.
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Affiliation(s)
- S Kaneko
- Department of Immunology, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
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Li M, Liu X, Robinson G, Bar-Peled U, Wagner KU, Young WS, Hennighausen L, Furth PA. Mammary-derived signals activate programmed cell death during the first stage of mammary gland involution. Proc Natl Acad Sci U S A 1997; 94:3425-30. [PMID: 9096410 PMCID: PMC20386 DOI: 10.1073/pnas.94.7.3425] [Citation(s) in RCA: 262] [Impact Index Per Article: 9.7] [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] [Indexed: 02/04/2023] Open
Abstract
Programmed cell death (PCD) of mammary alveolar cells during involution commences within hours of the end of suckling. Locally, milk accumulates within alveolar lumens; systemically, levels of lactogenic hormones fall. Four experimental models were used to define the role of local factors as compared with systemic hormones during the first and second stages of involution. In three models, milk release was disrupted in the presence of systemic lactogenic hormones: (i) sealing of the teats, (ii) mammary gland transplants that cannot release milk due to the absence of a teat connection, and (iii) inactivation of the oxytocin gene. The ability of systemic hormones to preserve lobular-alveolar structure without blocking PCD was illustrated using a fourth transgenic model of lactation failure. During the first stage of involution, local signals were sufficient to induce alveolar PCD even in the presence of systemic lactogenic hormones. PCD coincided with bax induction, decreased expression of milk proteins, block of prolactin signal transduction through Stat5a and 5b, and activation of Stat3. The two stages of mammary gland involution are regulated by progressive gain of death signals and loss of survival factors. This study demonstrates that genetic events that occur during the first reversible stage are controlled by local factors. These mammary-derived death signals are dominant over protective effects related to systemic hormone stimulation.
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Affiliation(s)
- M Li
- Department of Medicine, University of Maryland Medical School, Baltimore Veterans Affairs Medical Center, 21201, USA
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Abstract
Thrombopoietin (TPO) acts through its receptor, Mpl, to stimulate the proliferation and maturation of megakaryocytes and their progenitors. The Mpl cytoplasmic domain controls this process through assembly of an active signaling complex using various receptor docking sites. In this report, eight carboxyl truncations of the 121-aa murine Mpl cytoplasmic domain were tested for the ability to support growth of a cytokine-dependent cell line (Ba/F3) and for their capacity to induce TPO-stimulated tyrosine phosphorylation of specific signaling proteins. Point mutations of the five tyrosine residues in the cytoplasmic domain of the receptor were subsequently used to confirm our conclusions. From these studies we demonstrate that: (i) TPO-induced proliferation is moderately reduced by truncation of as many as 53 C-terminal amino acids of Mpl, including the sites of receptor tyrosine phosphorylation; (ii) truncation/mutation of residues 69-83 of the Mpl cytoplasmic domain enhances proliferative signaling, perhaps mediated by a decrease in receptor-driven cellular differentiation; (iii) Mpl can be phosphorylated at either Y112 or Y117 but not at the three proximal cytoplasmic tyrosine residues (Y8, Y29, and Y78); (iv) Y112 of Mpl is necessary for tyrosine phosphorylation of Shc and Shc-associated p145 (SHIP); and (v) unlike STAT3, STAT5 is partially phosphorylated in the absence of any tyrosine residues in the Mpl cytoplasmic domain. These studies identify subdomains of Mpl necessary for activation of several critical signaling pathways and point to two potentially novel mechanisms of TPO-induced signal transduction, an indirect pathway to STAT5 activation and a differentiation domain that acts by limiting proliferation.
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Affiliation(s)
- J G Drachman
- Division of Hematology, University of Washington Medical Center, Seattle 98195, USA.
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Berhow MT, Hiroi N, Kobierski LA, Hyman SE, Nestler EJ. Influence of cocaine on the JAK- STAT pathway in the mesolimbic dopamine system. J Neurosci 1996; 16:8019-26. [PMID: 8987828 PMCID: PMC6579209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/1996] [Revised: 09/17/1996] [Accepted: 09/20/1996] [Indexed: 02/03/2023] Open
Abstract
Chronic exposure to cocaine produces characteristic biochemical adaptations within the rat ventral tegmental area (VTA), a brain region rich in dopaminergic neurons implicated in the reinforcing and locomotor-activating properties of cocaine. Some of these changes are mimicked by chronic ciliary neurotrophic factor (CNTF) infusions into the same brain area. We show in this study that chronic cocaine treatment regulates the signal transduction pathway used by CNTF specifically in the VTA. There is an increase in immunoreactivity of Janus kinase (JAK2), a CNTF-regulated protein tyrosine kinase, in the VTA after chronic but not acute cocaine administration. This increase is not seen in the nearby substantia nigra or several other brain regions studied. Furthermore, this increase in JAK2 is not seen after chronic administration of other psychotropic drugs and was not observed for JAK1. The increase in JAK2 levels is associated with an increased responsiveness of the system to acute CNTF infusion into the VTA, as measured by induction in this brain region of signal transducers and activators of transcription (STAT) DNA binding activity and of Fos-like proteins, two known functional endpoints of JAK activation. Double-labeling immunohistochemical studies show that JAK2 immunoreactivity in the VTA is enriched in dopaminergic and nondopaminergic cells, both of which exhibit increased JAK2 immunoreactivity after chronic cocaine treatment. These findings suggest a scheme whereby some of the effects of chronic cocaine on VTA dopaminergic neurons are mediated directly by regulation of the JAK-STAT pathway in these cells, as well as perhaps indirectly by regulation of this pathway in nondopaminergic cells.
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Affiliation(s)
- M T Berhow
- Department of Psychiatry, Yale University School of Medicine, Connecticut Mental Health Center, New Haven, Connecticut 06508, USA
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