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Lee J, Park B, Moon B, Park J, Moon H, Kim K, Lee SA, Kim D, Min C, Lee DH, Lee G, Park D. A scaffold for signaling of Tim-4-mediated efferocytosis is formed by fibronectin. Cell Death Differ 2018; 26:1646-1655. [PMID: 30451988 DOI: 10.1038/s41418-018-0238-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 10/21/2018] [Accepted: 10/29/2018] [Indexed: 01/22/2023] Open
Abstract
An essential step during clearance of apoptotic cells is the recognition of phosphatidylserine (PS) exposed on apoptotic cells by its receptors on phagocytes. Tim-4 directly binding to PS and functioning as a tethering receptor for phagocytosis of apoptotic cells has been extensively studied over the past decade. However, the molecular mechanisms by which Tim-4 collaborates with other engulfment receptors during efferocytosis remain elusive. By comparing efferocytosis induced by Tim-4 with that by Anxa5-GPI, an artificial tethering receptor, we found that Tim-4 possesses auxiliary machinery to induce a higher level of efferocytosis than Anxa5-GPI. To search for that, we performed a yeast two-hybrid screen and identified Fibronectin (Fn1) as a novel Tim-4-associating protein. Tim-4 directly associated with Fn1 and formed a complex with integrins via the association of Fn1. Through Tim-4-/- mice and cell-based assays, we found that modulation of the Fn1 level affected efferocytosis induced by Tim-4 and disruption of the interaction between Tim-4 and Fn1 abrogated Tim-4-mediated efferocytosis. In addition, Tim-4 depletion attenuated integrin signaling activation and perturbation of integrin signaling suppressed Tim-4-promoted efferocytosis. Taken together, the data suggest that Fn1 locates Tim-4 and integrins in close proximity by acting as a scaffold, resulting in synergistic cooperation of Tim-4 with integrins for efficient efferocytosis.
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Affiliation(s)
- Juyeon Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Boyeon Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, 61755, Korea
| | - Byeongjin Moon
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Jeongjun Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Hyunji Moon
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Kwanhyeong Kim
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Sang-Ah Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Deokhwan Kim
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Chanhyuk Min
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Dae-Hee Lee
- Department of Oncology, College of Medicine, Korea University, Seoul, 08308, Korea
| | - Gwangrog Lee
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Daeho Park
- School of Life Sciences and Aging Research Institute, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea. .,Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea.
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52
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AXL phosphorylates and up-regulates TNS2 and its implications in IRS-1-associated metabolism in cancer cells. J Biomed Sci 2018; 25:80. [PMID: 30419905 PMCID: PMC6233515 DOI: 10.1186/s12929-018-0465-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 08/15/2018] [Indexed: 12/21/2022] Open
Abstract
Background TNS2 is a focal adhesions protein and a binding partner for many proteins, including the receptor tyrosine kinase Axl. Although TNS2 can bind with Axl, the details of their interactions have not been elucidated. TNS2 is involved in IRS-1 signaling pathway. In this study, we confirmed the relationship between TNS2 expression and the expression of Axl, IRS-1, PDK1 and Glut4 in pancreatic cancer patients. Methods The expression levels of TNS2, Axl, IRS-1, PDK1 and Glut4 in human cancer cells were measured by Western blot and/or IP-Western blot assays. Paired samples of pancreatic cancer and non-cancer tissues were obtained from 33 patients and were used to construct tissue microarrays. The expression levels of these markers in the tissue microarrays were measured by enzyme-linked Immunohistochemistry assay, and the relationships were analyzed by Pearson’s chi-square test and two-tailed t-test analysis. Results We demonstrated for the first time that TNS2 is a phosphorylation substrate of Axl. Moreover, we found a positive relationship between TNS2 expression and the expression of Axl, IRS-1, PDK1 and Glut4 in pancreatic cancer patients. Based on these results, we suggest that Axl modulates glucose metabolism potentially through TNS2 and IRS-1. We hypothesize that there exists a novel mechanism whereby Axl binds to and phosphorylates TNS2, releasing TNS2 from interaction with IRS-1 and resulting in increased stability of IRS-1. The two key enzymes of aerobic glycolysis (Glut4 and PDK1) were found to be up-regulated by Axl/TNS2/IRS-1 cross-talk and may play a critical role in glucose metabolism of cancer cells. Conclusions Our results revealed for the first time that Axl binds to and phosphorylates TNS2 and that Axl/TNS2/IRS-1 cross-talk may potentially play a critical role in glucose metabolism of cancer cells. Electronic supplementary material The online version of this article (10.1186/s12929-018-0465-x) contains supplementary material, which is available to authorized users.
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53
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Corpas R, Griñán-Ferré C, Palomera-Ávalos V, Porquet D, García de Frutos P, Franciscato Cozzolino SM, Rodríguez-Farré E, Pallàs M, Sanfeliu C, Cardoso BR. Melatonin induces mechanisms of brain resilience against neurodegeneration. J Pineal Res 2018; 65:e12515. [PMID: 29907977 DOI: 10.1111/jpi.12515] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/06/2018] [Indexed: 12/20/2022]
Abstract
Melatonin is an endogenous pleiotropic molecule which orchestrates regulatory functions and protective capacity against age-related ailments. The increase in circulating levels of melatonin through dietary supplements intensifies its health benefits. Investigations in animal models have shown that melatonin protects against Alzheimer's disease (AD)-like pathology, although clinical studies have not been conclusive. We hypothesized that melatonin induces changes in the brain that prevent or attenuate AD by increasing resilience. Therefore, we treated healthy nontransgenic (NoTg) and AD transgenic (3xTg-AD) 6-month-old mice with a daily dose of 10 mg/kg of melatonin until 12 months of age. As expected, melatonin reversed cognitive impairment and dementia-associated behaviors of anxiety and apathy and reduced amyloid and tau burden in 3xTg-AD mice. Remarkably, melatonin induced cognitive enhancement and higher wellness level-related behavior in NoTg mice. At the mechanism level, NF-κB and proinflammatory cytokine expressions were decreased in both NoTg and 3xTg-AD mice. The SIRT1 pathway of longevity and neuroprotection was also activated in both mouse strains after melatonin dosing. Furthermore, we explored new mechanisms and pathways not previously associated with melatonin treatment such as the ubiquitin-proteasome proteolytic system and the recently proposed neuroprotective Gas6/TAM pathway. The upregulation of proteasome activity and the modulation of Gas6 and its receptors by melatonin were similarly displayed by both NoTg and 3xTg-AD mice. Therefore, these results confirm the potential of melatonin treatment against AD pathology, by way of opening new pathways in its mechanisms of action, and demonstrating that melatonin induces cognitive enhancement and brain resilience against neurodegenerative processes.
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Affiliation(s)
- Rubén Corpas
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC and IDIBAPS, Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Christian Griñán-Ferré
- Faculty of Pharmacy and Food Sciences, Institut de Neurociències, Universitat de Barcelona and CIBERNED, Barcelona, Spain
| | - Verónica Palomera-Ávalos
- Faculty of Pharmacy and Food Sciences, Institut de Neurociències, Universitat de Barcelona and CIBERNED, Barcelona, Spain
| | - David Porquet
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC and IDIBAPS, Barcelona, Spain
| | - Pablo García de Frutos
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC and IDIBAPS, Barcelona, Spain
| | - Silvia M Franciscato Cozzolino
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Eduard Rodríguez-Farré
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC and IDIBAPS, Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Mercè Pallàs
- Faculty of Pharmacy and Food Sciences, Institut de Neurociències, Universitat de Barcelona and CIBERNED, Barcelona, Spain
| | - Coral Sanfeliu
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC and IDIBAPS, Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Bárbara R Cardoso
- Institute for Physical Activity and Nutrition Research (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, Vic., Australia
- The Florey Institute of Neuroscience and Mental Health, Melbourne, Vic., Australia
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54
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Martin NA, Nawrocki A, Molnar V, Elkjaer ML, Thygesen EK, Palkovits M, Acs P, Sejbaek T, Nielsen HH, Hegedus Z, Sellebjerg F, Molnar T, Barbosa EGV, Alcaraz N, Gallyas F, Svenningsen AF, Baumbach J, Lassmann H, Larsen MR, Illes Z. Orthologous proteins of experimental de- and remyelination are differentially regulated in the CSF proteome of multiple sclerosis subtypes. PLoS One 2018; 13:e0202530. [PMID: 30114292 PMCID: PMC6095600 DOI: 10.1371/journal.pone.0202530] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/03/2018] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE Here, we applied a multi-omics approach (i) to examine molecular pathways related to de- and remyelination in multiple sclerosis (MS) lesions; and (ii) to translate these findings to the CSF proteome in order to identify molecules that are differentially expressed among MS subtypes. METHODS To relate differentially expressed genes in MS lesions to de- and remyelination, we compared transcriptome of MS lesions to transcriptome of cuprizone (CPZ)-induced de- and remyelination. Protein products of the overlapping orthologous genes were measured within the CSF by quantitative proteomics, parallel reaction monitoring (PRM). Differentially regulated proteins were correlated with molecular markers of inflammation by using MesoScale multiplex immunoassay. Expression kinetics of differentially regulated orthologous genes and proteins were examined in the CPZ model. RESULTS In the demyelinated and remyelinated corpus callosum, we detected 1239 differentially expressed genes; 91 orthologues were also differentially expressed in MS lesions. Pathway analysis of these orthologues suggested that the TYROBP (DAP12)-TREM2 pathway, TNF-receptor 1, CYBA and the proteasome subunit PSMB9 were related to de- and remyelination. We designed 129 peptides representing 51 orthologous proteins, measured them by PRM in 97 individual CSF, and compared their levels between relapsing (n = 40) and progressive MS (n = 57). Four proteins were differentially regulated among relapsing and progressive MS: tyrosine protein kinase receptor UFO (UFO), TIMP-1, apolipoprotein C-II (APOC2), and beta-2-microglobulin (B2M). The orthologous genes/proteins in the mouse brain peaked during acute remyelination. UFO, TIMP-1 and B2M levels correlated inversely with inflammation in the CSF (IL-6, MCP-1/CCL2, TARC/CCL17). APOC2 showed positive correlation with IL-2, IL-16 and eotaxin-3/CCL26. CONCLUSIONS Pathology-based multi-omics identified four CSF markers that were differentially expressed in MS subtypes. Upregulated TIMP-1, UFO and B2M orthologues in relapsing MS were associated with reduced inflammation and reflected reparatory processes, in contrast to the upregulated orthologue APOC2 in progressive MS that reflected changes in lipid metabolism associated with increased inflammation.
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Affiliation(s)
- Nellie A. Martin
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Arkadiusz Nawrocki
- Department of Neurology, Odense University Hospital, Odense, Denmark
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Viktor Molnar
- Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, Hungary
| | - Maria L. Elkjaer
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Eva K. Thygesen
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Miklos Palkovits
- Laboratory of Neuromorphology and Human Brain Tissue Bank/Microdissection Laboratory, Semmelweis University, Budapest, Hungary
| | - Peter Acs
- Department of Neurology, University of Pecs, Pecs, Hungary
| | - Tobias Sejbaek
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Helle H. Nielsen
- Department of Neurology, Odense University Hospital, Odense, Denmark
| | - Zoltan Hegedus
- Laboratory of Bioinformatics, Biological Research Centre, Szeged, Hungary
| | - Finn Sellebjerg
- Danish Multiple Sclerosis Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Tihamer Molnar
- Department of Anaesthesiology and Intensive Therapy, University of Pecs, Pecs, Hungary
| | - Eudes G. V. Barbosa
- Computational Biology Group, Department of Mathematics and Computer Science, University of Southern Denmark, Odense, Denmark
| | - Nicolas Alcaraz
- Computational Biology Group, Department of Mathematics and Computer Science, University of Southern Denmark, Odense, Denmark
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ferenc Gallyas
- Department of Biochemistry and Medical Chemistry, University of Pecs, Pecs, Hungary
- Szentagothai Research Centre, University of Pécs, Pécs, Hungary
- Nuclear-Mitochondrial Interactions Research Group, Hungarian Academy of Sciences, Budapest, Hungary
| | - Asa F. Svenningsen
- Department of Neurobiology Research, Institute for Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Jan Baumbach
- Computational Biology Group, Department of Mathematics and Computer Science, University of Southern Denmark, Odense, Denmark
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Martin R. Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Zsolt Illes
- Department of Neurology, Odense University Hospital, Odense, Denmark
- Department of Neurology, University of Pecs, Pecs, Hungary
- Department of Clinical Research, BRIDGE, University of Southern Denmark, Odense, Denmark
- * E-mail:
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Bedoui Y, Neal JW, Gasque P. The Neuro-Immune-Regulators (NIREGs) Promote Tissue Resilience; a Vital Component of the Host's Defense Strategy against Neuroinflammation. J Neuroimmune Pharmacol 2018; 13:309-329. [PMID: 29909495 DOI: 10.1007/s11481-018-9793-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/24/2018] [Indexed: 01/29/2023]
Abstract
An effective protective inflammatory response in the brain is crucial for the clearance of pathogens (e.g. microbes, amyloid fibrils, prionSC) and should be closely regulated. However, the CNS seems to have limited tissue resilience to withstand the detrimental effects of uncontrolled inflammation compromising functional recovery and tissue repair. Newly described neuro-immune-regulators (NIREGs) are functionally related proteins regulating the severity and duration of the host inflammatory response. NIREGs such as CD200, CD47 and CX3CL1 are vital for increasing tissue resilience and are constitutively expressed by neurons. The interaction with co-receptors (CD200R, CD172a, CX3CR1) will maintain microglia in the resting phenotype, directing aggressive microglia phenotype and limiting bystander injuries. Neurons can also express many of the complement NIREGs (CD55, CD46, CD59 and factor H). Neurons and glia also express suppressor of cytokine signaling proteins (SOCS) down regulating janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway and to lead to the polarization of microglia towards anti-inflammatory phenotype. Other NIREGs such as serine protease inhibitors (serpins) and thrombomodulin (CD141) inhibit neurotoxic systemic coagulation proteins such as thrombin. The unfolded protein response (UPR) detects misfolded proteins and other stressors to prevent irreversible cell injury. Microglial pattern recognition receptors (PRR) (TREM-2, CR3, FcγR) are important to clear apoptotic cells and cellular debris but in non-phlogystic manner through inhibitory signaling pathways. The TYRO3, Axl, Mer (TAM) tyrosine receptor kinases activated by Gas 6 and PROS1 regulate inflammation by inhibiting Toll like receptors (TLR) /JAK-STAT activation and contribute to NIREG's functions.
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Affiliation(s)
- Yosra Bedoui
- Université de la Réunion, CRNS 9192, INSERM U1187, IRD249, Unité Mixte Processus Infectieux en Milieu Insulaire Tropical (PIMIT), Plateforme Technologique CYROI, Saint -Clotilde, La Réunion, France
| | - Jim W Neal
- Infection and Immunity, Cardiff University, Henry Wellcome Building, Cardiff, CF14 4XN, UK.
| | - Philippe Gasque
- Laboratoire de biologie, secteur laboratoire d'immunologie Clinique et expérimentale ZOI, LICE-OI, CHU Felix Guyon Bellepierre, St Denis, La Réunion, France.
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Law LA, Graham DK, Di Paola J, Branchford BR. GAS6/TAM Pathway Signaling in Hemostasis and Thrombosis. Front Med (Lausanne) 2018; 5:137. [PMID: 29868590 PMCID: PMC5954114 DOI: 10.3389/fmed.2018.00137] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 04/23/2018] [Indexed: 01/01/2023] Open
Abstract
The GAS6/TYRO3-AXL-MERTK (TAM) signaling pathway is essential for full and sustained platelet activation, as well as thrombus stabilization. Inhibition of this pathway decreases platelet aggregation, shape change, clot retraction, aggregate formation under flow conditions, and surface expression of activation markers. Transgenic mice deficient in GAS6, or any of the TAM family of receptors that engage this ligand, exhibit in vivo protection against arterial and venous thrombosis but do not demonstrate either spontaneous or prolonged bleeding compared to their wild-type counterparts. Comparable results are observed in wild-type mice treated with pharmacological inhibitors of the GAS6-TAM pathway. Thus, GAS6/TAM inhibition offers an attractive novel therapeutic option that may allow for a moderate reduction in platelet activation and decreased thrombosis while still permitting the primary hemostatic function of platelet plug formation.
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Affiliation(s)
- Luke A Law
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, United States
| | - Douglas K Graham
- Section of Hematology/Oncology, Department of Pediatrics, Emory University, Atlanta, GA, United States
| | - Jorge Di Paola
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States.,University of Colorado Hemophilia and Thrombosis Center, Aurora, CO, United States
| | - Brian R Branchford
- Section of Hematology/Oncology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, United States.,University of Colorado Hemophilia and Thrombosis Center, Aurora, CO, United States
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Migration/Invasion of Malignant Gliomas and Implications for Therapeutic Treatment. Int J Mol Sci 2018; 19:ijms19041115. [PMID: 29642503 PMCID: PMC5979613 DOI: 10.3390/ijms19041115] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 03/22/2018] [Accepted: 04/03/2018] [Indexed: 02/07/2023] Open
Abstract
Malignant tumors of the central nervous system (CNS) are among cancers with the poorest prognosis, indicated by their association with tumors of high-level morbidity and mortality. Gliomas, the most common primary CNS tumors that arise from neuroglial stem or progenitor cells, have estimated annual incidence of 6.6 per 100,000 individuals in the USA, and 3.5 per 100,000 individuals in Taiwan. Tumor invasion and metastasis are the major contributors to the deaths in cancer patients. Therapeutic goals including cancer stem cells (CSC), phenotypic shifts, EZH2/AXL/TGF-β axis activation, miRNAs and exosomes are relevant to GBM metastasis to develop novel targeted therapeutics for GBM and other brain cancers. Herein, we highlight tumor metastasis in our understanding of gliomas, and illustrate novel exosome therapeutic approaches in glioma, thereby paving the way towards innovative therapies in neuro-oncology.
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Shafit-Zagardo B, Gruber RC, DuBois JC. The role of TAM family receptors and ligands in the nervous system: From development to pathobiology. Pharmacol Ther 2018. [PMID: 29514053 DOI: 10.1016/j.pharmthera.2018.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tyro3, Axl, and Mertk, referred to as the TAM family of receptor tyrosine kinases, are instrumental in maintaining cell survival and homeostasis in mammals. TAM receptors interact with multiple signaling molecules to regulate cell migration, survival, phagocytosis and clearance of metabolic products and cell debris called efferocytosis. The TAMs also function as rheostats to reduce the expression of proinflammatory molecules and prevent autoimmunity. All three TAM receptors are activated in a concentration-dependent manner by the vitamin K-dependent growth arrest-specific protein 6 (Gas6). Gas6 and the TAMs are abundantly expressed in the nervous system. Gas6, secreted by neurons and endothelial cells, is the sole ligand for Axl. ProteinS1 (ProS1), another vitamin K-dependent protein functions mainly as an anti-coagulant, and independent of this function can activate Tyro3 and Mertk, but not Axl. This review will focus on the role of the TAM receptors and their ligands in the nervous system. We highlight studies that explore the function of TAM signaling in myelination, the visual cortex, neural cancers, and multiple sclerosis (MS) using Gas6-/- and TAM mutant mice models.
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Affiliation(s)
- Bridget Shafit-Zagardo
- Albert Einstein College of Medicine, Department of Pathology, 1300 Morris Park Avenue, Bronx, NY 10461, United States.
| | - Ross C Gruber
- Sanofi, Neuroinflammation and MS Research, 49 New York Ave, Framingham, MA 01701, United States
| | - Juwen C DuBois
- Albert Einstein College of Medicine, Department of Pathology, 1300 Morris Park Avenue, Bronx, NY 10461, United States
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59
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Rethinking Phagocytes: Clues from the Retina and Testes. Trends Cell Biol 2018; 28:317-327. [PMID: 29454661 DOI: 10.1016/j.tcb.2018.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/13/2018] [Accepted: 01/16/2018] [Indexed: 01/30/2023]
Abstract
Specialized phagocytes are a newly appreciated classification of phagocyte that currently encompasses Sertoli cells (SCs) of the testes and the retinal pigment epithelial cells (RPE) of the retina. While these cells support very different tissues, they have a striking degree of similarity both as phagocytes and in ways that go beyond cell clearance. The clearance of apoptotic germ cells, cell debris, and used photoreceptor outer segments are critical functions of these cells, and the unique nature of their clearance events make specialized phagocytes uniquely suited for studying the larger implications of cell clearance in vivo. The shared functions of specialized phagocytes could provide novel insights into how phagocytosis impacts tissue homeostasis and immune modulation. In this review, we examine the remarkable similarities between SCs and RPE as specialized phagocytes and the physiological effects of cell clearance within a tissue.
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Chang CF, Goods BA, Askenase MH, Hammond MD, Renfroe SC, Steinschneider AF, Landreneau MJ, Ai Y, Beatty HE, da Costa LHA, Mack M, Sheth KN, Greer DM, Huttner A, Coman D, Hyder F, Ghosh S, Rothlin CV, Love JC, Sansing LH. Erythrocyte efferocytosis modulates macrophages towards recovery after intracerebral hemorrhage. J Clin Invest 2018; 128:607-624. [PMID: 29251628 PMCID: PMC5785262 DOI: 10.1172/jci95612] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 11/07/2017] [Indexed: 02/03/2023] Open
Abstract
Macrophages are a source of both proinflammatory and restorative functions in damaged tissue through complex dynamic phenotypic changes. Here, we sought to determine whether monocyte-derived macrophages (MDMs) contribute to recovery after acute sterile brain injury. By profiling the transcriptional dynamics of MDMs in the murine brain after experimental intracerebral hemorrhage (ICH), we found robust phenotypic changes in the infiltrating MDMs over time and demonstrated that MDMs are essential for optimal hematoma clearance and neurological recovery. Next, we identified the mechanism by which the engulfment of erythrocytes with exposed phosphatidylserine directly modulated the phenotype of both murine and human MDMs. In mice, loss of receptor tyrosine kinases AXL and MERTK reduced efferocytosis of eryptotic erythrocytes and hematoma clearance, worsened neurological recovery, exacerbated iron deposition, and decreased alternative activation of macrophages after ICH. Patients with higher circulating soluble AXL had poor 1-year outcomes after ICH onset, suggesting that therapeutically augmenting efferocytosis may improve functional outcomes by both reducing tissue injury and promoting the development of reparative macrophage responses. Thus, our results identify the efferocytosis of eryptotic erythrocytes through AXL/MERTK as a critical mechanism modulating macrophage phenotype and contributing to recovery from ICH.
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Affiliation(s)
- Che-Feng Chang
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Brittany A. Goods
- Department of Biological Engineering, Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Michael H. Askenase
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Matthew D. Hammond
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Stephen C. Renfroe
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Margaret J. Landreneau
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Youxi Ai
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Hannah E. Beatty
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Luís Henrique Angenendt da Costa
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Matthias Mack
- Department of Internal Medicine (Nephrology), University of Regensburg, Regensburg, Germany
| | - Kevin N. Sheth
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - David M. Greer
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Daniel Coman
- Department of Diagnostic Radiology and Biomedical Engineering
| | - Fahmeed Hyder
- Department of Diagnostic Radiology and Biomedical Engineering
| | - Sourav Ghosh
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Pharmacology, and
| | - Carla V. Rothlin
- Department of Pharmacology, and
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - J. Christopher Love
- Chemical Engineering, Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lauren H. Sansing
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
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Davies SP, Reynolds GM, Stamataki Z. Clearance of Apoptotic Cells by Tissue Epithelia: A Putative Role for Hepatocytes in Liver Efferocytosis. Front Immunol 2018; 9:44. [PMID: 29422896 PMCID: PMC5790054 DOI: 10.3389/fimmu.2018.00044] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 01/08/2018] [Indexed: 12/11/2022] Open
Abstract
Toxic substances and microbial or food-derived antigens continuously challenge the liver, which is tasked with their safe neutralization. This vital organ is also important for the removal of apoptotic immune cells during inflammation and has been previously described as a “graveyard” for dying lymphocytes. The clearance of apoptotic and necrotic cells is known as efferocytosis and is a critical liver function to maintain tissue homeostasis. Much of the research into this form of immunological control has focused on Kupffer cells, the liver-resident macrophages. However, hepatocytes (and other liver resident cells) are competent efferocytes and comprise 80% of the liver mass. Little is known regarding the mechanisms of apoptotic and necrotic cell capture by epithelia, which lack key receptors that mediate phagocytosis in macrophages. Herein, we discuss recent developments that increased our understanding of efferocytosis in tissues, with a special focus on the liver parenchyma. We discuss the impact of efferocytosis in health and in inflammation, highlighting the role of phagocytic epithelia.
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Affiliation(s)
- Scott P Davies
- Centre for Liver Research, College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Gary M Reynolds
- Centre for Liver Research, College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,Centre for Liver Research and National Institute for Health Research (NIHR) Birmingham Liver Biomedical Research Unit, College of Medical and Dental Sciences, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Zania Stamataki
- Centre for Liver Research, College of Medical and Dental Sciences, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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62
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Ray AK, DuBois JC, Gruber RC, Guzik HM, Gulinello ME, Perumal G, Raine C, Kozakiewicz L, Williamson J, Shafit-Zagardo B. Loss of Gas6 and Axl signaling results in extensive axonal damage, motor deficits, prolonged neuroinflammation, and less remyelination following cuprizone exposure. Glia 2017; 65:2051-2069. [PMID: 28925029 DOI: 10.1002/glia.23214] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 01/08/2023]
Abstract
The TAM (Tyro3, Axl, and MerTK) family of receptor tyrosine kinases (RTKs) and their ligands, Gas6 and ProS1, are important for innate immune responses and central nervous system (CNS) homeostasis. While only Gas6 directly activates Axl, ProS1 activation of Tyro3/MerTK can indirectly activate Axl through receptor heterodimerization. Therefore, we generated Gas6-/- Axl-/- double knockout (DKO) mice to specifically examine the contribution of this signaling axis while retaining ProS1 signaling through Tyro3 and MerTK. We found that naïve young adult DKO and WT mice have comparable myelination and equal numbers of axons and oligodendrocytes in the corpus callosum. Using the cuprizone model of demyelination/remyelination, transmission electron microscopy revealed extensive axonal swellings containing autophagolysosomes and multivesicular bodies, and fewer myelinated axons in brains of DKO mice at 3-weeks recovery from a 6-week cuprizone diet. Analysis of immunofluorescent staining demonstrated more SMI32+ and APP+ axons and less myelin in the DKO mice. There were no significant differences in the number of GFAP+ astrocytes or Iba1+ microglia/macrophages between the groups of mice. However, at 6-weeks cuprizone and recovery, DKO mice had increased proinflammatory cytokine and altered suppressor of cytokine signaling (SOCS) mRNA expression supporting a role for Gas6-Axl signaling in proinflammatory cytokine suppression. Significant motor deficits in DKO mice relative to WT mice on cuprizone were also observed. These data suggest that Gas6-Axl signaling plays an important role in maintaining axonal integrity and regulating and reducing CNS inflammation that cannot be compensated for by ProS1/Tyro3/MerTK signaling.
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Affiliation(s)
- Alex K Ray
- Department of Pathology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, 10461
| | - Juwen C DuBois
- Department of Pathology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, 10461
| | - Ross C Gruber
- Neuroimmunology and MS Research, Sanofi, Framingham, Massachusetts, 01701
| | - Hillary M Guzik
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, 10461
| | - Maria E Gulinello
- Rodent Behavioral Core, Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, 10461
| | - Geoffrey Perumal
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, 10461
| | - Cedric Raine
- Department of Pathology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, 10461
| | - Lauren Kozakiewicz
- Department of Pathology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, 10461
| | - Julie Williamson
- Department of Pathology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, 10461
| | - Bridget Shafit-Zagardo
- Department of Pathology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York, 10461
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63
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Kurowska-Stolarska M, Alivernini S, Melchor EG, Elmesmari A, Tolusso B, Tange C, Petricca L, Gilchrist DS, Di Sante G, Keijzer C, Stewart L, Di Mario C, Morrison V, Brewer JM, Porter D, Milling S, Baxter RD, McCarey D, Gremese E, Lemke G, Ferraccioli G, McSharry C, McInnes IB. MicroRNA-34a dependent regulation of AXL controls the activation of dendritic cells in inflammatory arthritis. Nat Commun 2017. [PMID: 28639625 PMCID: PMC5489689 DOI: 10.1038/ncomms15877] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Current treatments for rheumatoid arthritis (RA) do not reverse underlying aberrant immune function. A genetic predisposition to RA, such as HLA-DR4 positivity, indicates that dendritic cells (DC) are of crucial importance to pathogenesis by activating auto-reactive lymphocytes. Here we show that microRNA-34a provides homoeostatic control of CD1c+ DC activation via regulation of tyrosine kinase receptor AXL, an important inhibitory DC auto-regulator. This pathway is aberrant in CD1c+ DCs from patients with RA, with upregulation of miR-34a and lower levels of AXL compared to DC from healthy donors. Production of pro-inflammatory cytokines is reduced by ex vivo gene-silencing of miR-34a. miR-34a-deficient mice are resistant to collagen-induced arthritis and interaction of DCs and T cells from these mice are reduced and do not support the development of Th17 cells in vivo. Our findings therefore show that miR-34a is an epigenetic regulator of DC function that may contribute to RA.
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Affiliation(s)
- Mariola Kurowska-Stolarska
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Stefano Alivernini
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Emma Garcia Melchor
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Aziza Elmesmari
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Barbara Tolusso
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Clare Tange
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Luca Petricca
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Derek S Gilchrist
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Gabriele Di Sante
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Chantal Keijzer
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Lynn Stewart
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Clara Di Mario
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Vicky Morrison
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - James M Brewer
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Duncan Porter
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Simon Milling
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Ronald D Baxter
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK.,NHS Greater Glasgow and Clyde, 1055 Great Western Road, Glasgow G12 0XH, UK
| | - David McCarey
- NHS Greater Glasgow and Clyde, 1055 Great Western Road, Glasgow G12 0XH, UK
| | - Elisa Gremese
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Greg Lemke
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Gianfranco Ferraccioli
- Division of Rheumatology, Fondazione Policlinico Universitario A. Gemelli, Catholic University of the Sacred Heart, Rome 00168, Italy
| | - Charles McSharry
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
| | - Iain B McInnes
- Institute of Infection, Immunity and Inflammation, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
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64
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Gay CM, Balaji K, Byers LA. Giving AXL the axe: targeting AXL in human malignancy. Br J Cancer 2017; 116:415-423. [PMID: 28072762 PMCID: PMC5318970 DOI: 10.1038/bjc.2016.428] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/21/2016] [Accepted: 11/23/2016] [Indexed: 12/14/2022] Open
Abstract
The receptor tyrosine kinase AXL, activated by a complex interaction between its ligand growth arrest-specific protein 6 and phosphatidylserine, regulates various vital cellular processes, including proliferation, survival, motility, and immunologic response. Although not implicated as an oncogenic driver itself, AXL, a member of the TYRO3, AXL, and MERTK family of receptor tyrosine kinases, is overexpressed in several haematologic and solid malignancies, including acute myeloid leukaemia, non-small cell lung cancer, gastric and colorectal adenocarcinomas, and breast and prostate cancers. In the context of malignancy, evidence suggests that AXL overexpression drives wide-ranging processes, including epithelial to mesenchymal transition, tumour angiogenesis, resistance to chemotherapeutic and targeted agents, and decreased antitumor immune response. As a result, AXL is an attractive candidate not only as a prognostic biomarker in malignancy but also as a target for anticancer therapies. Several AXL inhibitors are currently in preclinical and clinical development. This article reviews the structure, regulation, and function of AXL; the role of AXL in the tumour microenvironment; the development of AXL as a therapeutic target; and areas of ongoing and future investigation.
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Affiliation(s)
- Carl M Gay
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Kavitha Balaji
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Lauren Averett Byers
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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65
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Zhu K, Sun J, Kang Z, Zou Z, Wu G, Wang J. Electroacupuncture Promotes Remyelination after Cuprizone Treatment by Enhancing Myelin Debris Clearance. Front Neurosci 2017; 10:613. [PMID: 28119561 PMCID: PMC5222794 DOI: 10.3389/fnins.2016.00613] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 12/26/2016] [Indexed: 12/13/2022] Open
Abstract
Promoting remyelination is crucial for patients with demyelinating diseases including multiple sclerosis. However, it is still a circuitous conundrum finding a practical remyelinating therapy. Electroacupuncture (EA), originating from traditional Chinese medicine (TCM), has been widely used to treat CNS diseases all over the world, but the role of EA in demyelinating diseases is barely known. In this study, we examined the remyelinating properties and mechanisms of EA in cuprizone-induced demyelinating model, a CNS demyelinating murine model of multiple sclerosis. By feeding C57BL/6 mice with chow containing 0.2% cuprizone for 5 weeks, we successfully induce demyelination as proved by weight change, beam test, pole test, histomorphology, and Western Blot. EA treatment significantly improves the neurobehavioral performance at week 7 (2 weeks after withdrawing cuprizone chow). RNA-seq and RT-PCR results reveal up-regulated expression of myelin-related genes, and the expression of myelin associated protein (MBP, CNPase, and O4) are also increased after EA treatment, indicating therapeutic effect of EA on cuprizone model. It is widely acknowledged that microglia exert phagocytic effect on degraded myelin debris and clear these detrimental debris, which is a necessary process for subsequent remyelination. We found the remyelinating effect of EA is associated with enhanced clearance of degraded myelin debris as detected by dMBP staining and red oil O staining. Our further studies suggest that more microglia assemble in demyelinating area (corpus callosum) during the process of EA treatment, and cells inside corpus callosum are mostly in a plump, ameboid, and phagocytic shape, quite different from the ramified cells outside corpus callosum. RNA-seq result also unravels that most genes relating to positive regulation of phagocytosis (GO:0050766) are up-regulated, indicating enhanced phagocytic process after EA treatment. During the process of myelin debris clearance, microglia tend to change their phenotype toward M2 phenotype. Thus, we also probed into the phenotype of microglia in our study. Immuno-staining results show increased expression of CD206 and Arg1, and the ratio of CD206/CD16/32 are also higher in EA group. In conclusion, these results demonstrate for the first time that EA enhances myelin debris removal from activated microglia after demyelination, and promotes remyelination.
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Affiliation(s)
- Keying Zhu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan UniversityShanghai, China; State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghai, China; Academy of Integrative Medicine, Fudan UniversityShanghai, China
| | - Jingxian Sun
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan UniversityShanghai, China; State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghai, China; Academy of Integrative Medicine, Fudan UniversityShanghai, China
| | - Zheng Kang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan UniversityShanghai, China; State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghai, China; Academy of Integrative Medicine, Fudan UniversityShanghai, China
| | - Zaofeng Zou
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan UniversityShanghai, China; State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghai, China; Academy of Integrative Medicine, Fudan UniversityShanghai, China
| | - Gencheng Wu
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan UniversityShanghai, China; State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghai, China; Academy of Integrative Medicine, Fudan UniversityShanghai, China
| | - Jun Wang
- Department of Integrative Medicine and Neurobiology, School of Basic Medical Sciences, Shanghai Medical College, Fudan UniversityShanghai, China; State Key Laboratory of Medical Neurobiology, Collaborative Innovation Center for Brain Science, Institutes of Brain Science, Fudan UniversityShanghai, China; Academy of Integrative Medicine, Fudan UniversityShanghai, China
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66
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The Gas6/TAM System and Multiple Sclerosis. Int J Mol Sci 2016; 17:ijms17111807. [PMID: 27801848 PMCID: PMC5133808 DOI: 10.3390/ijms17111807] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/22/2016] [Accepted: 10/26/2016] [Indexed: 01/25/2023] Open
Abstract
Growth arrest specific 6 (Gas6) is a multimodular circulating protein, the biological actions of which are mediated by the interaction with three transmembrane tyrosine kinase receptors: Tyro3, Axl, and MerTK, collectively named TAM. Over the last few decades, many progresses have been done in the understanding of the biological activities of this highly pleiotropic system, which plays a role in the regulation of immune response, inflammation, coagulation, cell growth, and clearance of apoptotic bodies. Recent findings have further related Gas6 and TAM receptors to neuroinflammation in general and, specifically, to multiple sclerosis (MS). In this paper, we review the biology of the Gas6/TAM system and the current evidence supporting its potential role in the pathogenesis of MS.
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67
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The Role of TAM Family Receptors in Immune Cell Function: Implications for Cancer Therapy. Cancers (Basel) 2016; 8:cancers8100097. [PMID: 27775650 PMCID: PMC5082387 DOI: 10.3390/cancers8100097] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 01/30/2023] Open
Abstract
The TAM receptor protein tyrosine kinases-Tyro3, Axl, and Mer-are essential regulators of immune homeostasis. Guided by their cognate ligands Growth arrest-specific gene 6 (Gas6) and Protein S (Pros1), these receptors ensure the resolution of inflammation by dampening the activation of innate cells as well as by restoring tissue function through promotion of tissue repair and clearance of apoptotic cells. Their central role as negative immune regulators is highlighted by the fact that deregulation of TAM signaling has been linked to the pathogenesis of autoimmune, inflammatory, and infectious diseases. Importantly, TAM receptors have also been associated with cancer development and progression. In a cancer setting, TAM receptors have a dual regulatory role, controlling the initiation and progression of tumor development and, at the same time, the associated anti-tumor responses of diverse immune cells. Thus, modulation of TAM receptors has emerged as a potential novel strategy for cancer treatment. In this review, we discuss our current understanding of how TAM receptors control immunity, with a particular focus on the regulation of anti-tumor responses and its implications for cancer immunotherapy.
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68
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Goudarzi S, Rivera A, Butt AM, Hafizi S. Gas6 Promotes Oligodendrogenesis and Myelination in the Adult Central Nervous System and After Lysolecithin-Induced Demyelination. ASN Neuro 2016; 8:8/5/1759091416668430. [PMID: 27630207 PMCID: PMC5027908 DOI: 10.1177/1759091416668430] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/11/2016] [Indexed: 01/24/2023] Open
Abstract
A key aim of therapy for multiple sclerosis (MS) is to promote the regeneration of oligodendrocytes and remyelination in the central nervous system (CNS). The present study provides evidence that the vitamin K-dependent protein growth arrest specific 6 (Gas6) promotes such repair in in vitro cultures of mouse optic nerve and cerebellum. We first determined expression of Gas6 and TAM (Tyro3, Axl, Mer) receptors in the mouse CNS, with all three TAM receptors increasing in expression through postnatal development, reaching maximal levels in the adult. Treatment of cultured mouse optic nerves with Gas6 resulted in significant increases in oligodendrocyte numbers as well as expression of myelin basic protein (MBP). Gas6 stimulation also resulted in activation of STAT3 in optic nerves as well as downregulation of multiple genes involved in MS development, including matrix metalloproteinase-9 (MMP9), which may decrease the integrity of the blood-brain barrier and is found upregulated in MS lesions. The cytoprotective effects of Gas6 were examined in in vitro mouse cerebellar slice cultures, where lysolecithin was used to induce demyelination. Cotreatment of cerebellar slices with Gas6 significantly attenuated demyelination as determined by MBP immunostaining, and Gas6 activated Tyro3 receptor through its phosphorylation. In conclusion, these results demonstrate that Gas6/TAM signaling stimulates the generation of oligodendrocytes and increased myelin production via Tyro3 receptor in the adult CNS, including repair after demyelinating injury. Furthermore, the effects of Gas6 on STAT3 signaling and matrix MMP9 downregulation indicate potential glial cell repair and immunoregulatory roles for Gas6, indicating that Gas6-TAM signaling could be a potential therapeutic target in MS and other neuropathologies.
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Affiliation(s)
- Salman Goudarzi
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
| | - Andrea Rivera
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
| | - Arthur M Butt
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
| | - Sassan Hafizi
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
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69
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Orme JJ, Du Y, Vanarsa K, Mayeux J, Li L, Mutwally A, Arriens C, Min S, Hutcheson J, Davis LS, Chong BF, Satterthwaite AB, Wu T, Mohan C. Heightened cleavage of Axl receptor tyrosine kinase by ADAM metalloproteases may contribute to disease pathogenesis in SLE. Clin Immunol 2016; 169:58-68. [PMID: 27237127 PMCID: PMC5193537 DOI: 10.1016/j.clim.2016.05.011] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 12/26/2022]
Abstract
Systemic lupus erythematosus (SLE) is characterized by antibody-mediated chronic inflammation in the kidney, lung, skin, and other organs to cause inflammation and damage. Several inflammatory pathways are dysregulated in SLE, and understanding these pathways may improve diagnosis and treatment. In one such pathway, Axl tyrosine kinase receptor responds to Gas6 ligand to block inflammation in leukocytes. A soluble form of the Axl receptor ectodomain (sAxl) is elevated in serum from patients with SLE and lupus-prone mice. We hypothesized that sAxl in SLE serum originates from the surface of leukocytes and that the loss of leukocyte Axl contributes to the disease. We determined that macrophages and B cells are a source of sAxl in SLE and in lupus-prone mice. Shedding of the Axl ectodomain from the leukocytes of lupus-prone mice is mediated by the matrix metalloproteases ADAM10 and TACE (ADAM17). Loss of Axl from lupus-prone macrophages renders them unresponsive to Gas6-induced anti-inflammatory signaling in vitro. This phenotype is rescued by combined ADAM10/TACE inhibition. Mice with Axl-deficient macrophages develop worse disease than controls when challenged with anti-glomerular basement membrane (anti-GBM) sera in an induced model of nephritis. ADAM10 and TACE also mediate human SLE PBMC Axl cleavage. Collectively, these studies indicate that increased metalloprotease-mediated cleavage of leukocyte Axl may contribute to end organ disease in lupus. They further suggest dual ADAM10/TACE inhibition as a potential therapeutic modality in SLE.
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Affiliation(s)
- Jacob J Orme
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Yong Du
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; The Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States
| | - Kamala Vanarsa
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; The Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States
| | - Jessica Mayeux
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Li Li
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Azza Mutwally
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Cristina Arriens
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Soyoun Min
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Jack Hutcheson
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Laurie S Davis
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Benjamin F Chong
- The Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Anne B Satterthwaite
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States
| | - Tianfu Wu
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; The Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States
| | - Chandra Mohan
- The Department of Internal Medicine, Rheumatic Diseases Division, University of Texas Southwestern Medical Center, Dallas, TX 75390, United States; The Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, United States.
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70
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Analysis of receptor tyrosine kinase genetics identifies two novel risk loci in GAS6 and PROS1 in Behçet's disease. Sci Rep 2016; 6:26662. [PMID: 27222359 PMCID: PMC4879572 DOI: 10.1038/srep26662] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 04/29/2016] [Indexed: 12/23/2022] Open
Abstract
The TAM kinase (Tyro3, Axl, Mer) and its two ligands (Gas6 and protein S) have been shown to play an important regulatory role in the innate immune response. The present study aimed to investigate whether the tag single-nucleotide polymorphisms (tag SNPs) of these 5 protein-coding genes are associated with Behçet’s disease (BD). A two-stage association study was performed in a total of 907 BD patients and 1780 healthy controls. Altogether 32 polymorphisms were tested, using a Sequenom MassARRAY genotyping method in the first stage and a PCR-restriction fragment length polymorphism (PCR-RFLP) assay in the replication phase. Real-time PCR was performed to test the relative mRNA expression level of GAS6 and PROS1 from different SNP genotyped healthy individuals. The frequency of the C allele and CC genotype of rs9577873 in GAS6 (Pc = 4.92 × 10−5, Pc = 1.91 × 10−5, respectively) and A allele and AA genotype of rs4857037 in PROS1 (Pc = 1.85 × 10−6, Pc = 4.52 × 10−7, respectively) were significantly increased in BD. GAS6 expression in CC carriers of rs9577873 was significantly lower than that in CT/TT individuals (P = 0.001). Decreased expression of GAS6 and increased pro-inflammatory cytokines (IL-6 and IFN-γ: P = 4.23 × 10−4, P = 0.011, respectively) in individuals carrying the CC genotype suggest that the TAM-GAS6/PROS1 signal pathway may be involved in the pathogenesis of BD.
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Healy LM, Perron G, Won SY, Michell-Robinson MA, Rezk A, Ludwin SK, Moore CS, Hall JA, Bar-Or A, Antel JP. MerTK Is a Functional Regulator of Myelin Phagocytosis by Human Myeloid Cells. THE JOURNAL OF IMMUNOLOGY 2016; 196:3375-84. [PMID: 26962228 DOI: 10.4049/jimmunol.1502562] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 01/28/2016] [Indexed: 12/22/2022]
Abstract
Multifocal inflammatory lesions featuring destruction of lipid-rich myelin are pathologic hallmarks of multiple sclerosis. Lesion activity is assessed by the extent and composition of myelin uptake by myeloid cells present in such lesions. In the inflamed CNS, myeloid cells are comprised of brain-resident microglia, an endogenous cell population, and monocyte-derived macrophages, which infiltrate from the systemic compartment. Using microglia isolated from the adult human brain, we demonstrate that myelin phagocytosis is dependent on the polarization state of the cells. Myelin ingestion is significantly enhanced in cells exposed to TGF-β compared with resting basal conditions and markedly reduced in classically activated polarized cells. Transcriptional analysis indicated that TGF-β-treated microglia closely resembled M0 cells. The tyrosine kinase phagocytic receptor MerTK was one of the most upregulated among a select number of differentially expressed genes in TGF-β-treated microglia. In contrast, MerTK and its known ligands, growth arrest-specific 6 and Protein S, were downregulated in classically activated cells. MerTK expression and myelin phagocytosis were higher in CNS-derived microglia than observed in monocyte-derived macrophages, both basally and under all tested polarization conditions. Specific MerTK inhibitors reduced myelin phagocytosis and the resultant anti-inflammatory biased cytokine responses for both cell types. Defining and modulating the mechanisms that regulate myelin phagocytosis has the potential to impact lesion and disease evolution in multiple sclerosis. Relevant effects would include enhancing myelin clearance, increasing anti-inflammatory molecule production by myeloid cells, and thereby permitting subsequent tissue repair.
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Affiliation(s)
- Luke M Healy
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Gabrielle Perron
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - So-Yoon Won
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | | | - Ayman Rezk
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Samuel K Ludwin
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada; Department of Pathology and Molecular Medicine, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Craig S Moore
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St. John's, Newfoundland A1B 3V6, Canada; and
| | - Jeffery A Hall
- Department of Neurosurgery, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Amit Bar-Or
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Jack P Antel
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada;
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72
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Phagocytosis of apoptotic cells in homeostasis. Nat Immunol 2015; 16:907-17. [PMID: 26287597 DOI: 10.1038/ni.3253] [Citation(s) in RCA: 556] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 07/17/2015] [Indexed: 02/07/2023]
Abstract
Human bodies collectively turn over about 200 billion to 300 billion cells every day. Such turnover is an integral part of embryonic and postnatal development, as well as routine tissue homeostasis. This process involves the induction of programmed cell death in specific cells within the tissues and the specific recognition and removal of dying cells by a clearance 'crew' composed of professional, non-professional and specialized phagocytes. In the past few years, considerable progress has been made in identifying many features of apoptotic cell clearance. Some of these new observations challenge the way dying cells themselves are viewed, as well as how healthy cells interact with and respond to dying cells. Here we focus on the homeostatic removal of apoptotic cells in tissues.
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73
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Ma GZ, Giuffrida LL, Gresle MM, Haartsen J, Laverick L, Butzkueven H, Field J, Binder MD, Kilpatrick TJ. Association of plasma levels of Protein S with disease severity in multiple sclerosis. Mult Scler J Exp Transl Clin 2015; 1:2055217315596532. [PMID: 28607700 PMCID: PMC5433335 DOI: 10.1177/2055217315596532] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background The TAM family of receptor tyrosine kinases (TYRO3, AXL and MERTK) play important roles in modulating innate immune responses and central demyelination. The TAM receptor ligand Protein S (PROS) has also been shown to modulate innate immune cell responses. Objectives We assessed whether plasma levels of PROS are changed in multiple sclerosis (MS) patients and whether changes are associated with disease severity. Methods Plasma levels of total and free PROS were measured using enzyme-linked immunosorbent assay in a discovery cohort (MS: 65, control: 14) and an independent replication cohort (MS: 29, control: 29). The Multiple Sclerosis Severity Score (MSSS) was used to evaluate associations between plasma PROS levels and disease severity. Results We found plasma levels of total, but not free PROS, were decreased in MS patients compared with controls. In female MS patients, we observed decreases in total and free PROS levels compared with controls. In addition, we also observed higher MSSS in patients with very low levels of plasma free PROS. Conclusions These data suggest PROS may represent a potential marker of disease severity in MS.
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Affiliation(s)
- Gerry Zm Ma
- Multiple Sclerosis Division, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Australia
| | - Lauren L Giuffrida
- Multiple Sclerosis Division, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Australia
| | | | - Jodi Haartsen
- Eastern Clinical Research Unit, Department of Neurology, Box Hill Hospital, Monash University, Australia
| | - Louise Laverick
- The Department of Medicine, University of Melbourne, Australia
| | | | - Judith Field
- Multiple Sclerosis Division, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Australia
| | - Michele D Binder
- Multiple Sclerosis Division, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Australia
| | - Trevor J Kilpatrick
- Multiple Sclerosis Division, The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Australia
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74
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Holtman IR, Raj DD, Miller JA, Schaafsma W, Yin Z, Brouwer N, Wes PD, Möller T, Orre M, Kamphuis W, Hol EM, Boddeke EWGM, Eggen BJL. Induction of a common microglia gene expression signature by aging and neurodegenerative conditions: a co-expression meta-analysis. Acta Neuropathol Commun 2015; 3:31. [PMID: 26001565 PMCID: PMC4489356 DOI: 10.1186/s40478-015-0203-5] [Citation(s) in RCA: 409] [Impact Index Per Article: 45.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 04/12/2015] [Indexed: 12/16/2022] Open
Abstract
Introduction Microglia are tissue macrophages of the central nervous system that monitor brain homeostasis and react upon neuronal damage and stress. Aging and neurodegeneration induce a hypersensitive, pro-inflammatory phenotype, referred to as primed microglia. To determine the gene expression signature of priming, the transcriptomes of microglia in aging, Alzheimer’s disease (AD), and amyotrophic lateral sclerosis (ALS) mouse models were compared using Weighted Gene Co-expression Network Analysis (WGCNA). Results A highly consistent consensus transcriptional profile of up-regulated genes was identified, which prominently differed from the acute inflammatory gene network induced by lipopolysaccharide (LPS). Where the acute inflammatory network was significantly enriched for NF-κB signaling, the primed microglia profile contained key features related to phagosome, lysosome, antigen presentation, and AD signaling. In addition, specific signatures for aging, AD, and ALS were identified. Conclusion Microglia priming induces a highly conserved transcriptional signature with aging- and disease-specific aspects. Electronic supplementary material The online version of this article (doi:10.1186/s40478-015-0203-5) contains supplementary material, which is available to authorized users.
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75
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Vouri M, An Q, Birt M, Pilkington GJ, Hafizi S. Small molecule inhibition of Axl receptor tyrosine kinase potently suppresses multiple malignant properties of glioma cells. Oncotarget 2015; 6:16183-97. [PMID: 25980499 PMCID: PMC4599264 DOI: 10.18632/oncotarget.3952] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 04/09/2015] [Indexed: 12/14/2022] Open
Abstract
Glioblastoma multiforme (GBM) often features a combination of tumour suppressor gene inactivation and multiple oncogene overactivation. The Axl receptor tyrosine kinase is found overexpressed in GBM and thought to contribute to invasiveness, chemoresistance and poor survival. Here, we have evaluated the effect of BGB324, a clinical candidate Axl-specific small molecule inhibitor, on the invasive behaviour of human GBM cells in vitro, as an indicator of its potential in GBM therapy and also to elucidate the role of Axl in GBM pathogenesis.Two cultured adult GBM cell lines, SNB-19 and UP007, were treated with Gas6 and/or BGB324, and analysed in assays for survival, 3D colony growth, motility, migration and invasion. Western blot was used to detect protein expression and signal protein phosphorylation. In both cell lines, BGB324 inhibited specifically phosphorylation of Axl as well as Akt kinase further downstream. BGB324 also inhibited survival and proliferation of both cell lines in a concentration-dependent manner, as well as completely suppressing migration and invasion. Furthermore, our results indicate co-operative activation between the Axl and Tyro3 receptors, as well as ligand-independent Axl signalling, to take place in GBM cells. In conclusion, small molecule inhibitor-led targeting of Axl may be a promising therapy for GBM progression.
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Affiliation(s)
- Mikaella Vouri
- 1 Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Qian An
- 1 Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Matthew Birt
- 1 Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Geoffrey J. Pilkington
- 1 Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Sassan Hafizi
- 1 Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
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Targeted GAS6 delivery to the CNS protects axons from damage during experimental autoimmune encephalomyelitis. J Neurosci 2015; 34:16320-35. [PMID: 25471571 DOI: 10.1523/jneurosci.2449-14.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Growth arrest-specific protein 6 (GAS6) is a soluble agonist of the TYRO3, AXL, MERTK (TAM) family of receptor tyrosine kinases identified to have anti-inflammatory, neuroprotective, and promyelinating properties. During experimental autoimmune encephalomyelitis (EAE), wild-type (WT) mice demonstrate a significant induction of Gas6, Axl, and Mertk but not Pros1 or Tyro3 mRNA. We tested the hypothesis that intracerebroventricular delivery of GAS6 directly into the CNS of WT mice during myelin oligodendrocyte glycoprotein (MOG)-induced EAE would improve the clinical course of disease relative to artificial CSF (ACSF)-treated mice. GAS6 did not delay disease onset, but significantly reduced the clinical scores during peak and chronic EAE. Mice receiving GAS6 for 28 d had preserved SMI31(+) neurofilament immunoreactivity, significantly fewer SMI32(+) axonal swellings and spheroids and less demyelination relative to ACSF-treated mice. Alternate-day subcutaneous IFNβ injection did not enhance GAS6 treatment effectiveness. Gas6(-/-) mice sensitized with MOG35-55 peptide exhibit higher clinical scores during late peak to early chronic disease, with significantly increased SMI32(+) axonal swellings and Iba1(+) microglia/macrophages, enhanced expression of several proinflammatory mRNA molecules, and decreased expression of early oligodendrocyte maturation markers relative to WT mouse spinal cords with scores for 8 consecutive days. During acute EAE, flow cytometry showed significantly more macrophages but not T-cell infiltrates in Gas6(-/-) spinal cords than WT spinal cords. Our data are consistent with GAS6 being protective during EAE by dampening the inflammatory response, thereby preserving axonal integrity and myelination.
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77
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Rothlin CV, Carrera-Silva EA, Bosurgi L, Ghosh S. TAM receptor signaling in immune homeostasis. Annu Rev Immunol 2015; 33:355-91. [PMID: 25594431 DOI: 10.1146/annurev-immunol-032414-112103] [Citation(s) in RCA: 307] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The TAM receptor tyrosine kinases (RTKs)-TYRO3, AXL, and MERTK-together with their cognate agonists GAS6 and PROS1 play an essential role in the resolution of inflammation. Deficiencies in TAM signaling have been associated with chronic inflammatory and autoimmune diseases. Three processes regulated by TAM signaling may contribute, either independently or collectively, to immune homeostasis: the negative regulation of the innate immune response, the phagocytosis of apoptotic cells, and the restoration of vascular integrity. Recent studies have also revealed the function of TAMs in infectious diseases and cancer. Here, we review the important milestones in the discovery of these RTKs and their ligands and the studies that underscore the functional importance of this signaling pathway in physiological immune settings and disease.
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78
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Graham DK, DeRyckere D, Davies KD, Earp HS. The TAM family: phosphatidylserine sensing receptor tyrosine kinases gone awry in cancer. Nat Rev Cancer 2014; 14:769-85. [PMID: 25568918 DOI: 10.1038/nrc3847] [Citation(s) in RCA: 516] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The TYRO3, AXL (also known as UFO) and MERTK (TAM) family of receptor tyrosine kinases (RTKs) are aberrantly expressed in multiple haematological and epithelial malignancies. Rather than functioning as oncogenic drivers, their induction in tumour cells predominately promotes survival, chemoresistance and motility. The unique mode of maximal activation of this RTK family requires an extracellular lipid–protein complex. For example, the protein ligand, growth arrest-specific protein 6 (GAS6), binds to phosphatidylserine (PtdSer) that is externalized on apoptotic cell membranes, which activates MERTK on macrophages. This triggers engulfment of apoptotic material and subsequent anti-inflammatory macrophage polarization. In tumours, autocrine and paracrine ligands and apoptotic cells are abundant, which provide a survival signal to the tumour cell and favour an anti-inflammatory, immunosuppressive microenvironment. Thus, TAM kinase inhibition could stimulate antitumour immunity, reduce tumour cell survival, enhance chemosensitivity and diminish metastatic potential.
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79
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Abstract
The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context.
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80
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Lewis ND, Hill JD, Juchem KW, Stefanopoulos DE, Modis LK. RNA sequencing of microglia and monocyte-derived macrophages from mice with experimental autoimmune encephalomyelitis illustrates a changing phenotype with disease course. J Neuroimmunol 2014; 277:26-38. [PMID: 25270668 DOI: 10.1016/j.jneuroim.2014.09.014] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/07/2014] [Accepted: 09/15/2014] [Indexed: 12/11/2022]
Abstract
The role of microglia and monocyte-derived macrophages in experimental autoimmune encephalomyelitis pathogenesis has been controversial. To gain insight into their respective roles, we developed a method for differentiating between microglia and monocyte-derived macrophages in the CNS by flow cytometry utilizing anti-CD44 antibodies. We used this system to monitor changes in cell number, activation status, and gene expression by RNA sequencing over the course of disease. This in vivo characterization and RNA-Seq dataset improves our understanding of macrophage biology in the brain under inflammatory conditions and may lead to strategies to identify therapies for neuroinflammatory diseases.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/metabolism
- Base Sequence/genetics
- Base Sequence/physiology
- Cell Proliferation
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/chemically induced
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Female
- Flow Cytometry
- Macrophages, Peritoneal/metabolism
- Mice
- Mice, Inbred C57BL
- Microglia/metabolism
- Myelin-Oligodendrocyte Glycoprotein/toxicity
- Peptide Fragments/toxicity
- Signal Transduction/immunology
- Time Factors
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Affiliation(s)
- Nuruddeen D Lewis
- Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT 06877-0368, USA
| | - Jonathan D Hill
- Department of Research Networking, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, 06877-0368, USA
| | - Kathryn W Juchem
- Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT 06877-0368, USA
| | - Dimitria E Stefanopoulos
- Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT 06877-0368, USA
| | - Louise K Modis
- Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT 06877-0368, USA.
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81
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Hu X, Liou AKF, Leak RK, Xu M, An C, Suenaga J, Shi Y, Gao Y, Zheng P, Chen J. Neurobiology of microglial action in CNS injuries: receptor-mediated signaling mechanisms and functional roles. Prog Neurobiol 2014; 119-120:60-84. [PMID: 24923657 PMCID: PMC4121732 DOI: 10.1016/j.pneurobio.2014.06.002] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/31/2014] [Accepted: 06/03/2014] [Indexed: 12/28/2022]
Abstract
Microglia are the first line of immune defense against central nervous system (CNS) injuries and disorders. These highly plastic cells play dualistic roles in neuronal injury and recovery and are known for their ability to assume diverse phenotypes. A broad range of surface receptors are expressed on microglia and mediate microglial 'On' or 'Off' responses to signals from other host cells as well as invading microorganisms. The integrated actions of these receptors result in tightly regulated biological functions, including cell mobility, phagocytosis, the induction of acquired immunity, and trophic factor/inflammatory mediator release. Over the last few years, significant advances have been made toward deciphering the signaling mechanisms related to these receptors and their specific cellular functions. In this review, we describe the current state of knowledge of the surface receptors involved in microglial activation, with an emphasis on their engagement of distinct functional programs and their roles in CNS injuries. It will become evident from this review that microglial homeostasis is carefully maintained by multiple counterbalanced strategies, including, but not limited to, 'On' and 'Off' receptor signaling. Specific regulation of theses microglial receptors may be a promising therapeutic strategy against CNS injuries.
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Affiliation(s)
- Xiaoming Hu
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15240, USA.
| | - Anthony K F Liou
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| | - Mingyue Xu
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Chengrui An
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Jun Suenaga
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yejie Shi
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Ping Zheng
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China
| | - Jun Chen
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai, China; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15240, USA.
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82
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Mirshafiey A, Ghalamfarsa G, Asghari B, Azizi G. Receptor Tyrosine Kinase and Tyrosine Kinase Inhibitors: New Hope for Success in Multiple Sclerosis Therapy. INNOVATIONS IN CLINICAL NEUROSCIENCE 2014; 11:23-36. [PMID: 25337443 PMCID: PMC4204472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Receptor tyrosine kinases (RTKs) are essential components of signal transduction pathways that mediate cell-to-cell communication and their function as relay points for signaling pathways. They have a key role in numerous processes that control cellular proliferation and differentiation, regulate cell growth and cellular metabolism, and promote cell survival and apoptosis. Recently, the role of RTKs including TCR, FLT-3, c-Kit, c-Fms, PDGFR, ephrin, neurotrophin receptor, and TAM receptor in autoimmune disorder, especially rheumatoid arthritis and multiple sclerosis has been suggested. In multiple sclerosis pathogenesis, RTKs and their tyrosine kinase enzymes are selective important targets for tyrosine kinase inhibitor (TKI) agents. TKIs, compete with the ATP binding site of the catalytic domain of several tyrosine kinases, and act as small molecules that have a favorable safety profile in disease treatment. Up to now, the efficacy of TKIs in numerous animal models of MS has been demonstrated, but application of these drugs in human diseases should be tested in future clinical trials.
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Affiliation(s)
- Abbas Mirshafiey
- Dr. Mirshafiey is from the Departmant of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Dr. Ghalamfarsa is from Cellular & Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran; Dr. Asghari is from Antimicrobial Resistance Research Center, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran; Dr. Azizi is from Imam Hassan Mojtaba Hospital, Alborz University of Medical Sciences, Karaj, Iran
| | - Ghasem Ghalamfarsa
- Dr. Mirshafiey is from the Departmant of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Dr. Ghalamfarsa is from Cellular & Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran; Dr. Asghari is from Antimicrobial Resistance Research Center, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran; Dr. Azizi is from Imam Hassan Mojtaba Hospital, Alborz University of Medical Sciences, Karaj, Iran
| | - Babak Asghari
- Dr. Mirshafiey is from the Departmant of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Dr. Ghalamfarsa is from Cellular & Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran; Dr. Asghari is from Antimicrobial Resistance Research Center, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran; Dr. Azizi is from Imam Hassan Mojtaba Hospital, Alborz University of Medical Sciences, Karaj, Iran
| | - Gholamreza Azizi
- Dr. Mirshafiey is from the Departmant of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Dr. Ghalamfarsa is from Cellular & Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran; Dr. Asghari is from Antimicrobial Resistance Research Center, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran; Dr. Azizi is from Imam Hassan Mojtaba Hospital, Alborz University of Medical Sciences, Karaj, Iran
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83
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Abstract
Abstract
TAM receptors (Tyro3, Axl, and Mer) belong to a family of receptor tyrosine kinases that have important effects on hemostasis and inflammation. Also, they affect cell proliferation, survival, adhesion, and migration. TAM receptors can be activated by the vitamin K–dependent proteins Gas6 and protein S. Protein S is more commonly known as an important cofactor for protein C as well as a direct inhibitor of multiple coagulation factors. To our knowledge, the functions of Gas6 are limited to TAM receptor activation. When activated, the TAM receptors have effects on primary hemostasis and coagulation and display an anti-inflammatory or a proinflammatory effect, depending on cell type. To comprehend the effects that the TAM receptors and their ligands have on hemostasis and inflammation, we compare studies that report the different phenotypes displayed by mice with deficiencies in the genes of this receptor family and its ligands (protein S+/−, Gas6−/−, TAM−/−, and variations of these). In this manner, we aim to display which features are attributable to the different ligands. Because of the effects TAM receptors have on hemostasis, inflammation, and cancer growth, their modulation could make interesting therapeutic targets in thromboembolic disease, atherosclerosis, sepsis, autoimmune disease, and cancer.
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84
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Gas6 enhances axonal ensheathment by MBP+ membranous processes in human DRG/OL promyelinating co-cultures. ASN Neuro 2014; 6:e00135. [PMID: 24476104 PMCID: PMC4416394 DOI: 10.1042/an20130022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The molecular requirements for human myelination are incompletely defined, and further study is needed to fully understand the cellular mechanisms involved during development and in demyelinating diseases. We have established a human co-culture model to study myelination. Our earlier observations showed that addition of human γ-carboxylated growth-arrest-specific protein 6 (Gas6) to human oligodendrocyte progenitor cell (OPC) cultures enhanced their survival and maturation. Therefore, we explored the effect of Gas6 in co-cultures of enriched OPCs plated on axons of human fetal dorsal root ganglia explant. Gas6 significantly enhanced the number of myelin basic protein-positive (MBP+) oligodendrocytes with membranous processes parallel with and ensheathing axons relative to co-cultures maintained in defined medium only for 14 days. Gas6 did not increase the overall number of MBP+ oligodendrocytes/culture; however, it significantly increased the length of MBP+ oligodendrocyte processes in contact with and wrapping axons. Multiple oligodendrocytes were in contact with a single axon, and several processes from one oligodendrocyte made contact with one or multiple axons. Electron microscopy supported confocal Z-series microscopy demonstrating axonal ensheathment by MBP+ oligodendrocyte membranous processes in Gas6-treated co-cultures. Contacts between the axonal and oligodendrocyte membranes were evident and multiple wraps of oligodendrocyte membrane around the axon were visible supporting a model system in which to study events in human myelination and aspects of non-compact myelin formation.
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85
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Pierce AM, Keating AK. TAM receptor tyrosine kinases: expression, disease and oncogenesis in the central nervous system. Brain Res 2013; 1542:206-20. [PMID: 24184575 DOI: 10.1016/j.brainres.2013.10.049] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/18/2013] [Accepted: 10/24/2013] [Indexed: 01/10/2023]
Abstract
Receptor tyrosine kinases (RTKs) are cell surface proteins that tightly regulate a variety of downstream intra-cellular processes; ligand-receptor interactions result in cascades of signaling events leading to growth, proliferation, differentiation and migration. There are 58 described RTKs, which are further categorized into 20 different RTK families. When dysregulated or overexpressed, these RTKs are implicated in disordered growth, development, and oncogenesis. The TAM family of RTKs, consisting of Tyro3, Axl, and MerTK, is prominently expressed during the development and function of the central nervous system (CNS). Aberrant expression and dysregulated activation of TAM family members has been demonstrated in a variety of CNS-related disorders and diseases, including the most common but least treatable brain cancer in children and adults: glioblastoma multiforme.
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Affiliation(s)
- Angela M Pierce
- University of Colorado School of Medicine, Department of Pediatrics, 12800 E. 19th Avenue, P18-4105, MS 8302 Aurora, CO 80045, USA.
| | - Amy K Keating
- University of Colorado School of Medicine, Department of Pediatrics, 12800 E. 19th Avenue, P18-4105, MS 8302 Aurora, CO 80045, USA.
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Abstract
The TAM receptors--Tyro3, Axl, and Mer--comprise a unique family of receptor tyrosine kinases, in that as a group they play no essential role in embryonic development. Instead, they function as homeostatic regulators in adult tissues and organ systems that are subject to continuous challenge and renewal throughout life. Their regulatory roles are prominent in the mature immune, reproductive, hematopoietic, vascular, and nervous systems. The TAMs and their ligands--Gas6 and Protein S--are essential for the efficient phagocytosis of apoptotic cells and membranes in these tissues; and in the immune system, they act as pleiotropic inhibitors of the innate inflammatory response to pathogens. Deficiencies in TAM signaling are thought to contribute to chronic inflammatory and autoimmune disease in humans, and aberrantly elevated TAM signaling is strongly associated with cancer progression, metastasis, and resistance to targeted therapies.
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Affiliation(s)
- Greg Lemke
- Molecular Neurobiology Laboratory, Immunobiology and Microbial Pathogenesis Laboratory, The Salk Institute, La Jolla, California 92037
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87
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Ganesh K, Das A, Dickerson R, Khanna S, Parinandi NL, Gordillo GM, Sen CK, Roy S. Prostaglandin E₂ induces oncostatin M expression in human chronic wound macrophages through Axl receptor tyrosine kinase pathway. THE JOURNAL OF IMMUNOLOGY 2012; 189:2563-73. [PMID: 22844123 DOI: 10.4049/jimmunol.1102762] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Monocytes and macrophages (m) are plastic cells whose functions are governed by microenvironmental cues. Wound fluid bathing the wound tissue reflects the wound microenvironment. Current literature on wound inflammation is primarily based on the study of blood monocyte-derived macrophages, cells that have never been exposed to the wound microenvironment. We sought to compare pair-matched monocyte-derived macrophages with m isolated from chronic wounds of patients. Oncostatin M (OSM) was differentially overexpressed in pair-matched wound m. Both PGE₂ and its metabolite 13,14-dihydro-15-keto-PGE₂ (PGE-M) were abundant in wound fluid and induced OSM in wound-site m. Consistently, induction of OSM mRNA was observed in m isolated from PGE₂-enriched polyvinyl alcohol sponges implanted in murine wounds. Treatment of human THP-1 cell-derived m with PGE₂ or PGE-M caused dose-dependent induction of OSM. Characterization of the signal transduction pathways demonstrated the involvement of EP4 receptor and cAMP signaling. In human m, PGE₂ phosphorylated Axl, a receptor tyrosine kinase (RTK). Axl phosphorylation was also induced by a cAMP analogue demonstrating interplay between the cAMP and RTK pathways. PGE₂-dependent Axl phosphorylation led to AP-1 transactivation, which is directly implicated in inducible expression of OSM. Treatment of human m or mice excisional wounds with recombinant OSM resulted in an anti-inflammatory response as manifested by attenuated expression of endotoxin-induced TNF-α and IL-1β. OSM treatment also improved wound closure during the early inflammatory phase of healing. In summary, this work recognizes PGE₂ in the wound fluid as a potent inducer of m OSM, a cytokine with an anti-inflammatory role in cutaneous wound healing.
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Affiliation(s)
- Kasturi Ganesh
- Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA
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88
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Zheng Y, Wang Q, Xiao B, Lu Q, Wang Y, Wang X. Involvement of receptor tyrosine kinase Tyro3 in amyloidogenic APP processing and β-amyloid deposition in Alzheimer's disease models. PLoS One 2012; 7:e39035. [PMID: 22701746 PMCID: PMC3372537 DOI: 10.1371/journal.pone.0039035] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 05/15/2012] [Indexed: 01/11/2023] Open
Abstract
Alzheimer's disease (AD) is the most common progressive neurodegenerative disease known to humankind. It is characterized by brain atrophy, extracellular amyloid plaques, and intracellular neurofibril tangles. β-amyloid cascade is considered the major causative player in AD. Up until now, the mechanisms underlying the process of Aβ generation and accumulation in the brain have not been well understood. Tyro3 receptor belongs to the TAM receptor subfamily of receptor protein tyrosine kinases (RPTKs). It is specifically expressed in the neurons of the neocortex and hippocampus. In this study, we established a cell model stably expressing APPswe mutants and producing Aβ. We found that overexpression of Tyro3 receptor in the cell model significantly decreased Aβ generation and also down-regulated the expression of β-site amyloid precursor protein cleaving enzyme (BACE1). However, the effects of Tyro3 were inhibited by its natural ligand, Gas6, in a concentration-dependent manner. In order to confirm the role of Tyro3 in the progression of AD development, we generated an AD transgenic mouse model accompanied by Tyro3 knockdown. We observed a significant increase in the number of amyloid plaques in the hippocampus in the mouse model. More plaque-associated clusters of astroglia were also detected. The present study may help researchers determine the role of Tyro3 receptor in the neuropathology of AD.
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Affiliation(s)
- Yan Zheng
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Qi Wang
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Bing Xiao
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Qingjun Lu
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Yizheng Wang
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Xiaomin Wang
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
- * E-mail:
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