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Haslea ostrearia Pigment Marennine Affects Key Actors of Neuroinflammation and Decreases Cell Migration in Murine Neuroglial Cell Model. Int J Mol Sci 2023; 24:ijms24065388. [PMID: 36982463 PMCID: PMC10049552 DOI: 10.3390/ijms24065388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/06/2023] [Accepted: 03/09/2023] [Indexed: 03/16/2023] Open
Abstract
Haslea ostrearia, a cosmopolitan marine pennate diatom, produces a characteristic blue pigment called marennine that causes the greening of filter-feeding organisms, such as oysters. Previous studies evidenced various biological activities of purified marennine extract, such as antibacterial, antioxidant and antiproliferative effects. These effects could be beneficial to human health. However, the specific biological activity of marennine remains to be characterized, especially regarding primary cultures of mammals. In the present study, we aimed to determine in vitro the effects of a purified extract of marennine on neuroinflammatory and cell migratory processes. These effects were assessed at non-cytotoxic concentrations of 10 and 50μg/mL on primary cultures of neuroglial cells. Marennine strongly interacts with neuroinflammatory processes in the immunocompetent cells of the central nervous system, represented by astrocytes and microglial cells. An anti-migratory activity based on a neurospheres migration assay has also been observed. These results encourage further study of Haslea blue pigment effects, particularly the identification of molecular and cellular targets affected by marennine, and strengthen previous studies suggesting that marennine has bioactivities which could be beneficial for human health applications.
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2
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Interleukin-31 and soluble CD40L: new candidate serum biomarkers that predict therapeutic response in multiple sclerosis. Neurol Sci 2022; 43:6271-6278. [DOI: 10.1007/s10072-022-06276-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/11/2022] [Indexed: 11/25/2022]
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3
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Bernaus A, Blanco S, Sevilla A. Glia Crosstalk in Neuroinflammatory Diseases. Front Cell Neurosci 2020; 14:209. [PMID: 32848613 PMCID: PMC7403442 DOI: 10.3389/fncel.2020.00209] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 06/15/2020] [Indexed: 12/11/2022] Open
Abstract
Neuroinflammation constitutes a fundamental cellular process to signal the loss of brain homeostasis. Glial cells play a central role in orchestrating these neuroinflammation processes in both deleterious and beneficial ways. These cellular responses depend on their intercellular interactions with neurons, astrocytes, the blood–brain barrier (BBB), and infiltrated T cells in the central nervous system (CNS). However, this intercellular crosstalk seems to be activated by specific stimuli for each different neurological scenario. This review summarizes key studies linking neuroinflammation with certain neurodegenerative diseases such as Alzheimer disease (AD), Parkinson disease (PD), and amyotrophic lateral sclerosis (ALS) and for the development of better therapeutic strategies based on immunomodulation.
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Affiliation(s)
- Ada Bernaus
- Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Sandra Blanco
- Molecular Mechanisms Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), University of Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain
| | - Ana Sevilla
- Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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Chen X, Jiang M, Li H, Wang Y, Shen H, Li X, Zhang Y, Wu J, Yu Z, Chen G. CX3CL1/CX3CR1 axis attenuates early brain injury via promoting the delivery of exosomal microRNA-124 from neuron to microglia after subarachnoid hemorrhage. J Neuroinflammation 2020; 17:209. [PMID: 32664984 PMCID: PMC7362528 DOI: 10.1186/s12974-020-01882-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 06/25/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Microglial activation-mediated neuroinflammation is a major contributor to early brain injury (EBI) after subarachnoid hemorrhage (SAH). MicroRNA-124 (miR-124) is the most abundant miRNAs in the central nervous system (CNS) and plays a vital role in microglial activation by targeting protein CCAAT-enhancer-binding protein α (C/EBPα). It has been reported that the CX3CL1/CX3CR1 axis is involved in the delivery of miR-124 from neurons to microglia. METHODS An experimental rat SAH model was established by injecting autologous arterial blood into the prechiasmatic cistern, and cultured primary neurons and microglia were exposed to oxyhemoglobin to mimic SAH in vitro. We additionally exploited specific expression plasmids encoding CX3CL1 and CX3CR1. RESULTS We observed significant decreases in CX3CL1 and CX3CR1 in the brain tissues of SAH patients. We also observed decreases in the levels of CX3CL1 in neurons and CX3CR1 in microglia after SAH in rats. Moreover, microglia exhibited an activated phenotype with macrophage-like morphology and high levels of CD45 and major histocompatibility complex (MHC) class II after SAH. After overexpression of CX3CL1/CX3CR1, the level of CD45 and MHC class II and the release of inflammatory factors tumor necrosis factor α, interleukin 1α and complement 1q were significantly decreased. There was also increased neuronal degeneration and behavior dysfunction after SAH, both of which were inhibited by CX3CL1/CX3CR1 overexpression. Additionally, we found that the delivery of exosomal miR-124 from neurons to microglia was significantly reduced after SAH, accompanied by an increase in C/EBPα expression, and was inhibited by CX3CL1/CX3CR1 overexpression. In conclusion, the CX3CL1/CX3CR1 axis may play protective roles after SAH by promoting the delivery of exosomal miR-124 to microglia and attenuate microglial activation and neuroinflammation. CONCLUSIONS CX3CL1/CX3CR1 axis may be a potential intervention target for the inhibition of SAH-induced EBI by promoting exosome transport of miR-124 to microglia.
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Affiliation(s)
- Xiao Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Ming Jiang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Haiying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Yang Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.,Department of Neurosurgery, The First Affiliated Hospital of University of Science and Technology of China, 17 Lujiang Road, Hefei, 230001, China
| | - Haitao Shen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Xiang Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Yunhai Zhang
- Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, 215163, China
| | - Jiang Wu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China
| | - Zhengquan Yu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, 215006, China.
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5
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Gheorghe RO, Deftu A, Filippi A, Grosu A, Bica-Popi M, Chiritoiu M, Chiritoiu G, Munteanu C, Silvestro L, Ristoiu V. Silencing the Cytoskeleton Protein Iba1 (Ionized Calcium Binding Adapter Protein 1) Interferes with BV2 Microglia Functioning. Cell Mol Neurobiol 2020; 40:1011-1027. [PMID: 31950314 DOI: 10.1007/s10571-020-00790-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/07/2020] [Indexed: 01/31/2023]
Abstract
Iba1 (ionized calcium binding adapter protein 1) is a cytoskeleton protein specific only for microglia and macrophages, where it acts as an actin-cross linking protein. Although frequently regarded as a marker of activation, its involvement in cell migration, membrane ruffling, phagocytosis or in microglia remodeling during immunological surveillance of the brain suggest that Iba1 is not a simple cytoskeleton protein, but a signaling molecule involved in specific signaling pathways. In this study we investigated if Iba1 could also represent a drug target, and tested the hypothesis that its specific silencing with customized Iba1-siRNA can modulate microglia functioning. The results showed that Iba1-silenced BV2 microglia migrate less due to reduced proliferation and cell adhesion, while their phagocytic activity and P2x7 functioning was significantly increased. Our data are the proof of concept that Iba1 protein is a new microglia target, which opens a new therapeutic avenue for modulating microglia behavior.
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Affiliation(s)
- Roxana-Olimpia Gheorghe
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Alexandru Deftu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Alexandru Filippi
- Institute of Cellular Biology and Pathology 'Nicolae Simionescu' of the Romanian Academy, Bucharest, Romania
| | - Andreea Grosu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Melania Bica-Popi
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania
| | - Marioara Chiritoiu
- Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 06003, Bucharest, Romania
| | - Gabriela Chiritoiu
- Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 06003, Bucharest, Romania
| | - Cristian Munteanu
- Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 06003, Bucharest, Romania
| | - Luigi Silvestro
- Pharma Serv International, Sabinelor 52, 050853, Bucharest, Romania
| | - Violeta Ristoiu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Splaiul Independentei 91-95, Sector 5, 050095, Bucharest, Romania.
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6
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Beyond TCR Signaling: Emerging Functions of Lck in Cancer and Immunotherapy. Int J Mol Sci 2019; 20:ijms20143500. [PMID: 31315298 PMCID: PMC6679228 DOI: 10.3390/ijms20143500] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/08/2019] [Accepted: 07/12/2019] [Indexed: 01/10/2023] Open
Abstract
In recent years, the lymphocyte-specific protein tyrosine kinase (Lck) has emerged as one of the key molecules regulating T-cell functions. Studies using Lck knock-out mice or Lck-deficient T-cell lines have shown that Lck regulates the initiation of TCR signaling, T-cell development, and T-cell homeostasis. Because of the crucial role of Lck in T-cell responses, strategies have been employed to redirect Lck activity to improve the efficacy of chimeric antigen receptors (CARs) and to potentiate T-cell responses in cancer immunotherapy. In addition to the well-studied role of Lck in T cells, evidence has been accumulated suggesting that Lck is also expressed in the brain and in tumor cells, where it actively takes part in signaling processes regulating cellular functions like proliferation, survival and memory. Therefore, Lck has emerged as a novel druggable target molecule for the treatment of cancer and neuronal diseases. In this review, we will focus on these new functions of Lck.
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7
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Szepesi Z, Manouchehrian O, Bachiller S, Deierborg T. Bidirectional Microglia-Neuron Communication in Health and Disease. Front Cell Neurosci 2018; 12:323. [PMID: 30319362 PMCID: PMC6170615 DOI: 10.3389/fncel.2018.00323] [Citation(s) in RCA: 290] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022] Open
Abstract
Microglia are ramified cells that exhibit highly motile processes, which continuously survey the brain parenchyma and react to any insult to the CNS homeostasis. Although microglia have long been recognized as a crucial player in generating and maintaining inflammatory responses in the CNS, now it has become clear, that their function are much more diverse, particularly in the healthy brain. The innate immune response and phagocytosis represent only a little segment of microglia functional repertoire that also includes maintenance of biochemical homeostasis, neuronal circuit maturation during development and experience-dependent remodeling of neuronal circuits in the adult brain. Being equipped by numerous receptors and cell surface molecules microglia can perform bidirectional interactions with other cell types in the CNS. There is accumulating evidence showing that neurons inform microglia about their status and thus are capable of controlling microglial activation and motility while microglia also modulate neuronal activities. This review addresses the topic: how microglia communicate with other cell types in the brain, including fractalkine signaling, secreted soluble factors and extracellular vesicles. We summarize the current state of knowledge of physiological role and function of microglia during brain development and in the mature brain and further highlight microglial contribution to brain pathologies such as Alzheimer’s and Parkinson’s disease, brain ischemia, traumatic brain injury, brain tumor as well as neuropsychiatric diseases (depression, bipolar disorder, and schizophrenia).
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Affiliation(s)
- Zsuzsanna Szepesi
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Oscar Manouchehrian
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Sara Bachiller
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
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8
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Ouali Alami N, Schurr C, Olde Heuvel F, Tang L, Li Q, Tasdogan A, Kimbara A, Nettekoven M, Ottaviani G, Raposo C, Röver S, Rogers-Evans M, Rothenhäusler B, Ullmer C, Fingerle J, Grether U, Knuesel I, Boeckers TM, Ludolph A, Wirth T, Roselli F, Baumann B. NF-κB activation in astrocytes drives a stage-specific beneficial neuroimmunological response in ALS. EMBO J 2018; 37:embj.201798697. [PMID: 29875132 PMCID: PMC6092622 DOI: 10.15252/embj.201798697] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 04/24/2018] [Accepted: 04/30/2018] [Indexed: 12/21/2022] Open
Abstract
Astrocytes are involved in non‐cell‐autonomous pathogenic cascades in amyotrophic lateral sclerosis (ALS); however, their role is still debated. We show that astrocytic NF‐κB activation drives microglial proliferation and leukocyte infiltration in the SOD1 (G93A) ALS model. This response prolongs the presymptomatic phase, delaying muscle denervation and decreasing disease burden, but turns detrimental in the symptomatic phase, accelerating disease progression. The transition corresponds to a shift in the microglial phenotype showing two effects that can be dissociated by temporally controlling NF‐κB activation. While NF‐κB activation in astrocytes induced a Wnt‐dependent microglial proliferation in the presymptomatic phase with neuroprotective effects on motoneurons, in later stage, astrocyte NF‐κB‐dependent microglial activation caused an accelerated disease progression. Notably, suppression of the early microglial response by CB2R agonists had acute detrimental effects. These data identify astrocytes as important regulators of microglia expansion and immune response. Therefore, stage‐dependent microglia modulation may be an effective therapeutic strategy in ALS.
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Affiliation(s)
| | - Christine Schurr
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
| | | | - Linyun Tang
- Department of Neurology, Ulm University, Ulm, Germany
| | - Qian Li
- Department of Neurology, Ulm University, Ulm, Germany
| | | | - Atsushi Kimbara
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Matthias Nettekoven
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Giorgio Ottaviani
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Catarina Raposo
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Stephan Röver
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Mark Rogers-Evans
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Benno Rothenhäusler
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Christoph Ullmer
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Jürgen Fingerle
- Natural and Medical Sciences Institute, Tübingen University, Reutlingen, Germany
| | - Uwe Grether
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Irene Knuesel
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Tobias M Boeckers
- Department of Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | | | - Thomas Wirth
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
| | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany .,Department of Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Bernd Baumann
- Institute of Physiological Chemistry, Ulm University, Ulm, Germany
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9
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CD45 in human physiology and clinical medicine. Immunol Lett 2018; 196:22-32. [PMID: 29366662 DOI: 10.1016/j.imlet.2018.01.009] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 01/20/2023]
Abstract
CD45 is an evolutionary highly conserved receptor protein tyrosine phosphatase exclusively expressed on all nucleated cells of the hematopoietic system. It is characterized by the expression of several isoforms, specific to a certain cell type and the developmental or activation status of the cell. CD45 is one of the key players in the initiation of T cell receptor signaling by controlling the activation of the Src family protein-tyrosine kinases Lck and Fyn. CD45 deficiency results in T- and B-lymphocyte dysfunction in the form of severe combined immune deficiency. It also plays a significant role in autoimmune diseases and cancer as well as in infectious diseases including fungal infections. The knowledge collected on CD45 biology is rather vast, but it remains unclear whether all findings in rodent immune cells also apply to human CD45. This review focuses on human CD45 expression and function and provides an overview on its ligands and role in human pathology.
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Zhang Z, Jyoti A, Balakrishnan B, Williams M, Singh S, Chugani DC, Kannan S. Trajectory of inflammatory and microglial activation markers in the postnatal rabbit brain following intrauterine endotoxin exposure. Neurobiol Dis 2017; 111:153-162. [PMID: 29274431 DOI: 10.1016/j.nbd.2017.12.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/17/2017] [Accepted: 12/19/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Maternal infection is a risk factor for periventricular leukomalacia and cerebral palsy (CP) in neonates. We have previously demonstrated hypomyelination and motor deficits in newborn rabbits, as seen in patients with cerebral palsy, following maternal intrauterine endotoxin administration. This was associated with increased microglial activation, primarily involving the periventricular region (PVR). In this study we hypothesized that maternal intrauterine inflammation leads to a pro-inflammatory environment in the PVR that is associated with microglial activation in the first 2 postnatal weeks. METHODS Timed pregnant New Zealand white rabbits underwent laparotomy on gestational day 28 (G28). They were randomly divided to receive lipopolysaccharide (LPS; 20μg/kg in 1mL saline) (Endotoxin group) or saline (1mL) (control saline, CS group), administrated along the wall of the uterus. The PVR from the CS and Endotoxin kits were harvested at G29 (1day post-injury), postnatal day1 (PND1, 3day post-injury) and PND5 (7days post-injury) for real-time PCR, ELISA and immunohistochemistry. Kits from CS and Endotoxin groups underwent longitudinal MicroPET imaging, with [11C]PK11195, a tracer for microglial activation. RESULTS We found that intrauterine endotoxin exposure resulted in pro-inflammatory microglial activation in the PVR of rabbits in the first postnatal week. This was evidenced by increased TSPO (translocator protein) expression co-localized with microglia/macrophages in the PVR, and changes in the microglial morphology (ameboid soma and retracted processes). In addition, CD11b level significantly increased with a concomitant decline in the CD45 level in the PVR at G29 and PND1. There was a significant elevation of pro-inflammatory cytokines and iNOS, and decreased anti-inflammatory markers in the Endotoxin kits at G29, PND1 and PND5. Increased [11C]PK11195 binding to the TSPO measured in vivo by PET imaging in the brain of Endotoxin kits was present up to PND14-17. CONCLUSIONS Our results indicate that a robust pro-inflammatory microglial phenotype/brain milieu commenced within 24h after LPS exposure and persisted through PND5 and in vivo TSPO binding was found at PND14-17. This suggests that there may be a window of opportunity to treat after birth. Therapies aimed at inducing an anti-inflammatory phenotype in microglia might promote recovery in maternal inflammation induced neonatal brain injury.
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Affiliation(s)
- Zhi Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Amar Jyoti
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Bindu Balakrishnan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Monica Williams
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Sarabdeep Singh
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Diane C Chugani
- Nemours/AI duPont Hospital for Children, Wilmington, DE, United States; Communication Sciences and Disorders Department, University of Delaware, Newark, DE, United States
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States.
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11
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Pena-Philippides JC, Caballero-Garrido E, Lordkipanidze T, Roitbak T. In vivo inhibition of miR-155 significantly alters post-stroke inflammatory response. J Neuroinflammation 2016; 13:287. [PMID: 27829437 PMCID: PMC5103429 DOI: 10.1186/s12974-016-0753-x] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 10/27/2016] [Indexed: 12/12/2022] Open
Abstract
Background MicroRNA miR-155 is implicated in modulation of the inflammatory processes in various pathological conditions. In our previous studies, we demonstrated that in vivo inhibition of miR-155 promotes functional recovery after mouse experimental stroke. In the present study, we explored if this beneficial effect is associated with miR-155 inhibition-induced alterations in post-stroke inflammatory response. Methods Intravenous injections of a specific miR-155 inhibitor were initiated at 48 h after mouse distal middle cerebral artery occlusion (dMCAO). Temporal changes in the expression of cytokines and key molecules associated with cytokine signaling were assessed at 7, 14, and 21 days after dMCAO, using mouse cytokine gene and protein arrays and Western blot analyses. Electron and immunofluorescence confocal microscopy techniques were used to evaluate the ultrastructural changes, as well as altered expression of specific phenotypic markers, at different time points after dMCAO. Results In the inhibitor-injected mice (inhibitor group), there was a significant decrease in CCL12 and CXCL3 cytokine expression at 7 days and significantly increased levels of major cytokines IL-10, IL-4, IL-6, MIP-1α, IL-5, and IL-17 at 14 days after dMCAO. These temporal changes correlated with altered expression of miR-155 target proteins SOCS-1, SHIP-1, and C/EBP-β and phosphorylation levels of cytokine signaling regulator STAT-3. Electron microscopy showed decreased number of phagocytically active peri-vascular microglia/macrophages in the inhibitor samples. Immunofluorescence and Western blot of these samples demonstrated that expression of leukocyte/ macrophage marker CD45 and phagocytosis marker CD68 was reduced at 7 days, and in contrast, significantly increased at 14 days after dMCAO, as compared to controls. Conclusions Based on our findings, we propose that in vivo miR-155 inhibition following mouse stroke significantly alters the time course of the expression of major cytokines and inflammation-associated molecules, which could influence inflammation process and tissue repair after experimental cerebral ischemia. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0753-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan Carlos Pena-Philippides
- Department of Neurosurgery, University of New Mexico Health Sciences Center, 1101 Yale Blvd, Albuquerque, NM, 87106-3834, USA
| | - Ernesto Caballero-Garrido
- Department of Neurosurgery, University of New Mexico Health Sciences Center, 1101 Yale Blvd, Albuquerque, NM, 87106-3834, USA
| | | | - Tamara Roitbak
- Department of Neurosurgery, University of New Mexico Health Sciences Center, 1101 Yale Blvd, Albuquerque, NM, 87106-3834, USA.
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12
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Pérez Del Palacio J, Díaz C, de la Cruz M, Annang F, Martín J, Pérez-Victoria I, González-Menéndez V, de Pedro N, Tormo JR, Algieri F, Rodriguez-Nogales A, Rodríguez-Cabezas ME, Reyes F, Genilloud O, Vicente F, Gálvez J. High-Throughput Screening Platform for the Discovery of New Immunomodulator Molecules from Natural Product Extract Libraries. ACTA ACUST UNITED AC 2016; 21:567-78. [PMID: 26962874 DOI: 10.1177/1087057116635517] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 02/05/2016] [Indexed: 11/15/2022]
Abstract
It is widely accepted that central nervous system inflammation and systemic inflammation play a significant role in the progression of chronic neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease, neurotropic viral infections, stroke, paraneoplastic disorders, traumatic brain injury, and multiple sclerosis. Therefore, it seems reasonable to propose that the use of anti-inflammatory drugs might diminish the cumulative effects of inflammation. Indeed, some epidemiological studies suggest that sustained use of anti-inflammatory drugs may prevent or slow down the progression of neurodegenerative diseases. However, the anti-inflammatory drugs and biologics used clinically have the disadvantage of causing side effects and a high cost of treatment. Alternatively, natural products offer great potential for the identification and development of bioactive lead compounds into drugs for treating inflammatory diseases with an improved safety profile. In this work, we present a validated high-throughput screening approach in 96-well plate format for the discovery of new molecules with anti-inflammatory/immunomodulatory activity. The in vitro models are based on the quantitation of nitrite levels in RAW264.7 murine macrophages and interleukin-8 in Caco-2 cells. We have used this platform in a pilot project to screen a subset of 5976 noncytotoxic crude microbial extracts from the MEDINA microbial natural product collection. To our knowledge, this is the first report on an high-throughput screening of microbial natural product extracts for the discovery of immunomodulators.
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Affiliation(s)
- José Pérez Del Palacio
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Caridad Díaz
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Mercedes de la Cruz
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Frederick Annang
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Jesús Martín
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Ignacio Pérez-Victoria
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Víctor González-Menéndez
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Nuria de Pedro
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - José R Tormo
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Francesca Algieri
- CIBER-EHD, Department of Pharmacology, ibs. Granada, Center for Biomedical Research (CIBM), University of Granada, Granada, Spain
| | - Alba Rodriguez-Nogales
- CIBER-EHD, Department of Pharmacology, ibs. Granada, Center for Biomedical Research (CIBM), University of Granada, Granada, Spain
| | - M Elena Rodríguez-Cabezas
- CIBER-EHD, Department of Pharmacology, ibs. Granada, Center for Biomedical Research (CIBM), University of Granada, Granada, Spain
| | - Fernando Reyes
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Olga Genilloud
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Francisca Vicente
- Fundación MEDINA, Parque Tecnológico Ciencias de la Salud, Avenida del Conocimiento 34, 18016, Granada, Spain
| | - Julio Gálvez
- CIBER-EHD, Department of Pharmacology, ibs. Granada, Center for Biomedical Research (CIBM), University of Granada, Granada, Spain
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Complex regulation of acute and chronic neuroinflammatory responses in mouse models deficient for nuclear factor kappa B p50 subunit. Neurobiol Dis 2014; 64:16-29. [DOI: 10.1016/j.nbd.2013.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 11/11/2013] [Accepted: 12/04/2013] [Indexed: 12/29/2022] Open
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Guillot-Sestier MV, Town T. Innate immunity in Alzheimer's disease: a complex affair. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2014; 12:593-607. [PMID: 23574177 DOI: 10.2174/1871527311312050008] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/20/2012] [Accepted: 12/21/2012] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is characterized by three major histopathological hallmarks: β-amyloid deposits, neurofibrillary tangles and gliosis. While neglected for decades, the neuroinflammatory processes coordinated by microglia are now accepted as etiologic events in AD evolution. Microglial cells are found in close vicinity to amyloid plaques and display various activation phenotypes determined by the expression of a wide range of cytokines, chemokines, and innate immune surface receptors. During the development of AD pathology, microglia fail to restrict amyloid plaques and may contribute to neurotoxicity and cognitive deficit. Nevertheless, under specific activation states, microglia can participate in cerebral amyloid clearance. This review focuses on the complex relationship between microglia and Aβ pathology, and highlights both deleterious and beneficial roles of microglial activation states in the context of AD. A deeper understanding of microglial biology will hopefully pave the way for next-generation AD therapeutic approaches aimed at harnessing these enigmatic innate immune cells of the central nervous system.
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Affiliation(s)
- Marie-Victoire Guillot-Sestier
- Regenerative Medicine Institute Neural Program, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Steven Spielberg Building Room 345, Los Angeles, CA 90048, USA
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15
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Chavarría A, Cárdenas G. Neuronal influence behind the central nervous system regulation of the immune cells. Front Integr Neurosci 2013; 7:64. [PMID: 24032006 PMCID: PMC3759003 DOI: 10.3389/fnint.2013.00064] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 08/07/2013] [Indexed: 12/29/2022] Open
Abstract
Central nervous system (CNS) has a highly specialized microenvironment, and despite being initially considered an immune privileged site, this immune status is far from absolute because it varies with age and brain topography. The brain monitors immune responses by several means that act in parallel; one pathway involves afferent nerves (vagal nerve) and the other resident cells (neurons and glia). These cell populations exert a strong role in the regulation of the immune system, favoring an immune-modulatory environment in the CNS. Neurons control glial cell and infiltrated T-cells by contact-dependent and -independent mechanisms. Contact-dependent mechanisms are provided by several membrane immune modulating molecules such as Sema-7A, CD95L, CD22, CD200, CD47, NCAM, ICAM-5, and cadherins; which can inhibit the expression of microglial inflammatory cytokines, induce apoptosis or inactivate infiltrated T-cells. On the other hand, soluble neuronal factors like Sema-3A, cytokines, neurotrophins, neuropeptides, and neurotransmitters attenuate microglial and/or T-cell activation. In this review, we focused on all known mechanism driven only by neurons in order to control the local immune cells.
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Affiliation(s)
- Anahí Chavarría
- Laboratorio de Neuroinmunología, Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México México City, México
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Montgomery SL, Narrow WC, Mastrangelo MA, Olschowka JA, O'Banion MK, Bowers WJ. Chronic neuron- and age-selective down-regulation of TNF receptor expression in triple-transgenic Alzheimer disease mice leads to significant modulation of amyloid- and Tau-related pathologies. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:2285-97. [PMID: 23567638 DOI: 10.1016/j.ajpath.2013.02.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/16/2013] [Accepted: 02/21/2013] [Indexed: 12/16/2022]
Abstract
Neuroinflammation, through production of proinflammatory molecules and activated glial cells, is implicated in Alzheimer's disease (AD) pathogenesis. One such proinflammatory mediator is tumor necrosis factor α (TNF-α), a multifunctional cytokine produced in excess and associated with amyloid β-driven inflammation and cognitive decline. Long-term global inhibition of TNF receptor type I (TNF-RI) and TNF-RII signaling without cell or stage specificity in triple-transgenic AD mice exacerbates hallmark amyloid and neurofibrillary tangle pathology. These observations revealed that long-term pan anti-TNF-α inhibition accelerates disease, cautions against long-term use of anti-TNF-α therapeutics for AD, and urges more selective regulation of TNF signaling. We used adeno-associated virus vector-delivered siRNAs to selectively knock down neuronal TNF-R signaling. We demonstrate divergent roles for neuronal TNF-RI and TNF-RII where loss of opposing TNF-RII leads to TNF-RI-mediated exacerbation of amyloid β and Tau pathology in aged triple-transgenic AD mice. Dampening of TNF-RII or TNF-RI+RII leads to a stage-independent increase in Iba-1-positive microglial staining, implying that neuronal TNF-RII may act nonautonomously on the microglial cell population. These results reveal that TNF-R signaling is complex, and it is unlikely that all cells and both receptors will respond positively to broad anti-TNF-α treatments at various stages of disease. In aggregate, these data further support the development of cell-, stage-, and/or receptor-specific anti-TNF-α therapeutics for AD.
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MESH Headings
- Adenoviridae/genetics
- Aging/metabolism
- Alzheimer Disease/genetics
- Alzheimer Disease/metabolism
- Alzheimer Disease/pathology
- Amyloid beta-Peptides/metabolism
- Animals
- Brain/pathology
- Disease Progression
- Down-Regulation/physiology
- Gene Knockdown Techniques
- Genetic Vectors
- Male
- Mice
- Mice, Transgenic
- Microglia/metabolism
- Neurons/metabolism
- Plaque, Amyloid/metabolism
- RNA, Small Interfering/genetics
- Receptors, Tumor Necrosis Factor/biosynthesis
- Receptors, Tumor Necrosis Factor/deficiency
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor, Type I/biosynthesis
- Receptors, Tumor Necrosis Factor, Type I/deficiency
- Receptors, Tumor Necrosis Factor, Type I/genetics
- Receptors, Tumor Necrosis Factor, Type II/biosynthesis
- Receptors, Tumor Necrosis Factor, Type II/deficiency
- Receptors, Tumor Necrosis Factor, Type II/genetics
- Signal Transduction/physiology
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Affiliation(s)
- Sara L Montgomery
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York 14642, USA
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17
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The role of Src kinase in macrophage-mediated inflammatory responses. Mediators Inflamm 2012; 2012:512926. [PMID: 23209344 PMCID: PMC3504478 DOI: 10.1155/2012/512926] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 09/28/2012] [Indexed: 12/28/2022] Open
Abstract
Src kinase (Src) is a tyrosine protein kinase that regulates cellular metabolism, survival, and proliferation. Many studies have shown that Src plays multiple roles in macrophage-mediated innate immunity, such as phagocytosis, the production of inflammatory cytokines/mediators, and the induction of cellular migration, which strongly implies that Src plays a pivotal role in the functional activation of macrophages. Macrophages are involved in a variety of immune responses and in inflammatory diseases including rheumatoid arthritis, atherosclerosis, diabetes, obesity, cancer, and osteoporosis. Previous studies have suggested roles for Src in macrophage-mediated inflammatory responses; however, recently, new functions for Src have been reported, implying that Src functions in macrophage-mediated inflammatory responses that have not been described. In this paper, we discuss recent studies regarding a number of these newly defined functions of Src in macrophage-mediated inflammatory responses. Moreover, we discuss the feasibility of Src as a target for the development of new pharmaceutical drugs to treat macrophage-mediated inflammatory diseases. We provide insights into recent reports regarding new functions for Src that are related to macrophage-related inflammatory responses and the development of novel Src inhibitors with strong immunosuppressive and anti-inflammatory properties, which could be applied to various macrophage-mediated inflammatory diseases.
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18
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Dhawan G, Combs CK. Inhibition of Src kinase activity attenuates amyloid associated microgliosis in a murine model of Alzheimer's disease. J Neuroinflammation 2012; 9:117. [PMID: 22673542 PMCID: PMC3388011 DOI: 10.1186/1742-2094-9-117] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 06/06/2012] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Microglial activation is an important histologic characteristic of the pathology of Alzheimer's disease (AD). One hypothesis is that amyloid beta (Aβ) peptide serves as a specific stimulus for tyrosine kinase-based microglial activation leading to pro-inflammatory changes that contribute to disease. Therefore, inhibiting Aβ stimulation of microglia may prove to be an important therapeutic strategy for AD. METHODS Primary murine microglia cultures and the murine microglia cell line, BV2, were used for stimulation with fibrillar Aβ1-42. The non-receptor tyrosine kinase inhibitor, dasatinib, was used to treat the cells to determine whether Src family kinase activity was required for the Aβ stimulated signaling response and subsequent increase in TNFα secretion using Western blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. A histologic longitudinal analysis was performed using an AD transgenic mouse model, APP/PS1, to determine an age at which microglial protein tyrosine kinase levels increased in order to administer dasatinib via mini osmotic pump diffusion. Effects of dasatinib administration on microglial and astroglial activation, protein phosphotyrosine levels, active Src kinase levels, Aβ plaque deposition, and spatial working memory were assessed via immunohistochemistry, Western blot, and T maze analysis. RESULTS Aβ fibrils stimulated primary murine microglia via a tyrosine kinase pathway involving Src kinase that was attenuated by dasatinib. Dasatinib administration to APP/PS1 mice decreased protein phosphotyrosine, active Src, reactive microglia, and TNFα levels in the hippocampus and temporal cortex. The drug had no effect on GFAP levels, Aβ plaque load, or the related tyrosine kinase, Lyn. These anti-inflammatory changes correlated with improved performance on the T maze test in dasatinib infused animals compared to control animals. CONCLUSIONS These data suggest that amyloid dependent microgliosis may be Src kinase dependent in vitro and in vivo. This study defines a role for Src kinase in the microgliosis characteristic of diseased brains and suggests that particular tyrosine kinase inhibition may be a valid anti-inflammatory approach to disease. Dasatinib is an FDA-approved drug for treating chronic myeloid leukemia cancer with a reported ability to cross the blood-brain barrier. Therefore, this suggests a novel use for this drug as well as similar acting molecules.
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Affiliation(s)
- Gunjan Dhawan
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, Grand Forks, ND, 58203, USA
| | - Colin K Combs
- School of Medicine and Health Sciences, 504 Hamline St., Room 118, Grand Forks, ND, 58203, USA
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Kim JY, Kim DH, Kim JH, Lee D, Jeon HB, Kwon SJ, Kim SM, Yoo YJ, Lee EH, Choi SJ, Seo SW, Lee JI, Na DL, Yang YS, Oh W, Chang JW. Soluble intracellular adhesion molecule-1 secreted by human umbilical cord blood-derived mesenchymal stem cell reduces amyloid-β plaques. Cell Death Differ 2011; 19:680-91. [PMID: 22015609 PMCID: PMC3307982 DOI: 10.1038/cdd.2011.140] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Presently, co-culture of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) with BV2 microglia under amyloid-β42 (Aβ42) exposure induced a reduction of Aβ42 in the medium as well as an overexpression of the Aβ-degrading enzyme neprilysin (NEP) in microglia. Cytokine array examinations of co-cultured media revealed elevated release of soluble intracellular adhesion molecule-1 (sICAM-1) from hUCB-MSCs. Administration of human recombinant ICAM-1 in BV2 cells and wild-type mice brains induced NEP expression in time- and dose-dependent manners. In co-culturing with BV2 cells under Aβ42 exposure, knockdown of ICAM-1 expression on hUCB-MSCs by small interfering RNA (siRNA) abolished the induction of NEP in BV2 cells as well as reduction of added Aβ42 in the co-cultured media. By contrast, siRNA-mediated inhibition of the sICAM-1 receptor, lymphocyte function-associated antigen-1 (LFA-1), on BV2 cells reduced NEP expression by ICAM-1 exposure. When hUCB-MSCs were transplanted into the hippocampus of a 10-month-old transgenic mouse model of Alzheimer's disease for 10, 20, or 40 days, NEP expression was increased in the mice brains. Moreover, Aβ42 plaques in the hippocampus and other regions were decreased by active migration of hUCB-MSCs toward Aβ deposits. These data suggest that hUCB-MSC-derived sICAM-1 decreases Aβ plaques by inducing NEP expression in microglia through the sICAM-1/LFA-1 signaling pathway.
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Affiliation(s)
- J-Y Kim
- Biomedical Research Institute, MEDIPOST Co. Ltd., Seoul 137-874, Republic of Korea
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CD45 deficiency drives amyloid-β peptide oligomers and neuronal loss in Alzheimer's disease mice. J Neurosci 2011; 31:1355-65. [PMID: 21273420 DOI: 10.1523/jneurosci.3268-10.2011] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Converging lines of evidence indicate dysregulation of the key immunoregulatory molecule CD45 (also known as leukocyte common antigen) in Alzheimer's disease (AD). We report that transgenic mice overproducing amyloid-β peptide (Aβ) but deficient in CD45 (PSAPP/CD45(-/-) mice) faithfully recapitulate AD neuropathology. Specifically, we find increased abundance of cerebral intracellular and extracellular soluble oligomeric and insoluble Aβ, decreased plasma soluble Aβ, increased abundance of microglial neurotoxic cytokines tumor necrosis factor-α and interleukin-1β, and neuronal loss in PSAPP/CD45(-/-) mice compared with CD45-sufficient PSAPP littermates (bearing mutant human amyloid precursor protein and mutant human presenilin-1 transgenes). After CD45 ablation, in vitro and in vivo studies demonstrate an anti-Aβ phagocytic but proinflammatory microglial phenotype. This form of microglial activation occurs with elevated Aβ oligomers and neural injury and loss as determined by decreased ratio of anti-apoptotic Bcl-xL to proapoptotic Bax, increased activated caspase-3, mitochondrial dysfunction, and loss of cortical neurons in PSAPP/CD45(-/-) mice. These data show that deficiency in CD45 activity leads to brain accumulation of neurotoxic Aβ oligomers and validate CD45-mediated microglial clearance of oligomeric Aβ as a novel AD therapeutic target.
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Salemi J, Obregon DF, Cobb A, Reed S, Sadic E, Jin J, Fernandez F, Tan J, Giunta B. Flipping the switches: CD40 and CD45 modulation of microglial activation states in HIV associated dementia (HAD). Mol Neurodegener 2011; 6:3. [PMID: 21223591 PMCID: PMC3030526 DOI: 10.1186/1750-1326-6-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 01/11/2011] [Indexed: 12/21/2022] Open
Abstract
Microglial dysfunction is associated with the pathogenesis and progression of a number of neurodegenerative disorders including HIV associated dementia (HAD). HIV promotion of an M1 antigen presenting cell (APC) - like microglial phenotype, through the promotion of CD40 activity, may impair endogenous mechanisms important for amyloid- beta (Aβ) protein clearance. Further, a chronic pro-inflammatory cycle is established in this manner. CD45 is a protein tyrosine phosphatase receptor which negatively regulates CD40L-CD40-induced microglial M1 activation; an effect leading to the promotion of an M2 phenotype better suited to phagocytose and clear Aβ. Moreover, this CD45 mediated activation state appears to dampen harmful cytokine production. As such, this property of microglial CD45 as a regulatory "off switch" for a CD40-promoted M1, APC-type microglia activation phenotype may represent a critical therapeutic target for the prevention and treatment of neurodegeneration, as well as microglial dysfunction, found in patients with HAD.
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Affiliation(s)
- Jon Salemi
- Department of Psychiatry and Neurosciences, Neuroimmunology Laboratory, University of South Florida, College of Medicine, Tampa, FL 33613, USA.
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22
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Dupéré-Minier G, Desharnais P, Bernier J. Involvement of tyrosine phosphatase CD45 in apoptosis. Apoptosis 2010; 15:1-13. [PMID: 19856105 DOI: 10.1007/s10495-009-0413-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
CD45 is a transmembrane molecule with phosphatase activity expressed in all nucleated haematopoietic cells and plays a major role in immune cells. It is a protein tyrosine phosphatase that is essential for antigen-receptor-mediated signal transduction by regulating Src family members that initiate TCR signaling. CD45 is being attributed a new emerging role as an apoptosis regulator. Cross-linking of the extracellular portion of the CD45 by monoclonal antibodies and by galectin-1, can induce apoptosis in T and B cells. Interestingly, this phosphatase has also been involved in nuclear apoptosis induced by mitochondrial perturbing agents. Furthermore, it is involved in apoptosis induced by HIV-1. CD45 defect is implicated in various diseases such as severe-combined immunodeficiency disease (SCID), acquired immunodeficiency syndrome (AIDS), lymphoma and multiple myelomas. The understanding of the mechanisms by which CD45 regulates apoptosis would be very useful in disease treatment.
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23
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Başterzi AD, Yazici K, Buturak V, Cimen B, Yazici A, Eskandari G, Tot Acar S, Taşdelen B. Effects of venlafaxine and fluoxetine on lymphocyte subsets in patients with major depressive disorder: a flow cytometric analysis. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:70-5. [PMID: 19804808 DOI: 10.1016/j.pnpbp.2009.09.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 09/14/2009] [Accepted: 09/27/2009] [Indexed: 12/20/2022]
Abstract
BACKGROUND Studies have yielded conflicting results concerning flow cytometric lymphocyte analyses in patients with depression. Data about the effect of antidepressants on lymphocyte subsets are also contradictory. The aim of this study was to determine effects of venlafaxine versus fluoxetine on lymphocyte subsets in depressive patients. METHODS Sixty-nine patients diagnosed with major depressive disorder (MDD) according to DSM-IV and 36 healthy controls are included in the study. Sixty-nine patients were randomized to take fluoxetine (FLX) (n=33) or venlafaxine (VEN) (n=36). Serum lymphocyte subsets included CD3, CD4, CD8, CD16/56, CD19, CD45, Anti-HLA-DR which were measured by flow cytometric analyses at baseline and 6 weeks after the start of treatment. The severity of depression was evaluated with Hamilton rating scale for depression. RESULTS At baseline, patients with MDD had significantly lower CD16/56 ratio and higher CD45 ratio compared to the controls. Although numerically higher in the VEN treated patients, treatment response rates between the FLX (53%) and the VEN (75%) groups were not different statistically. CD45 values decreased significantly in the VEN group at the end of the 6 week treatment period whereas no difference was observed in the FLX group. By the 6th week, treatment responders showed a significantly higher CD16/56 ratio than non-responders. Baseline severity of depression and anxiety was positively correlated with baseline CD45 ratio and negatively correlated with baseline CD16/56 ratio. We did not observe consistent changes in the absolute number of circulating B or T cells, nor in the helper/inducer (CD4) or suppressor/cytotoxic (CD8) subsets. CONCLUSIONS CD16/56 was lower in patients with MDD and increased in treatment responders at 6th week. CD45 ratio was higher in patients with MDD than healthy subjects; it decreased with antidepressant treatment and was positively correlated with the severity of depression. Antidepressant treatment contributes to immune regulation in patients with major depressive disorder.
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Affiliation(s)
- Ayşe Devrim Başterzi
- Department of Psychiatry, Mersin University Faculty of Medicine, Zeytinlibahçe Cad., 33079-Mersin, Turkey.
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Tsuda M, Masuda T, Kitano J, Shimoyama H, Tozaki-Saitoh H, Inoue K. IFN-gamma receptor signaling mediates spinal microglia activation driving neuropathic pain. Proc Natl Acad Sci U S A 2009; 106:8032-7. [PMID: 19380717 PMCID: PMC2683100 DOI: 10.1073/pnas.0810420106] [Citation(s) in RCA: 215] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Indexed: 01/23/2023] Open
Abstract
Neuropathic pain, a highly debilitating pain condition that commonly occurs after nerve damage, is a reflection of the aberrant excitability of dorsal horn neurons. This pathologically altered neurotransmission requires a communication with spinal microglia activated by nerve injury. However, how normal resting microglia become activated remains unknown. Here we show that in naive animals spinal microglia express a receptor for the cytokine IFN-gamma (IFN-gammaR) in a cell-type-specific manner and that stimulating this receptor converts microglia into activated cells and produces a long-lasting pain hypersensitivity evoked by innocuous stimuli (tactile allodynia, a hallmark symptom of neuropathic pain). Conversely, ablating IFN-gammaR severely impairs nerve injury-evoked microglia activation and tactile allodynia without affecting microglia in the contralateral dorsal horn or basal pain sensitivity. We also find that IFN-gamma-stimulated spinal microglia show up-regulation of Lyn tyrosine kinase and purinergic P2X(4) receptor, crucial events for neuropathic pain, and genetic approaches provide evidence linking these events to IFN-gammaR-dependent microglial and behavioral alterations. These results suggest that IFN-gammaR is a key element in the molecular machinery through which resting spinal microglia transform into an activated state that drives neuropathic pain.
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Affiliation(s)
- Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Takahiro Masuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Junko Kitano
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Hiroshi Shimoyama
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Hidetoshi Tozaki-Saitoh
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
| | - Kazuhide Inoue
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
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Gibbings D, Befus AD. CD4 and CD8: an inside-out coreceptor model for innate immune cells. J Leukoc Biol 2009; 86:251-9. [PMID: 19401396 DOI: 10.1189/jlb.0109040] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
CD8 and CD4 are expressed by several cell types that do not express TCR. These include DCs, macrophages, monocytes, and NK cells. CD8(+) monocytes and macrophages are abundant at the site of pathology in many rat disease models, particularly those involving immune complex-mediated pathology. Indeed, in some disease models, CD8(+) macrophages correlate with severity of pathology or directly cause pathology or tumor cell killing. Evidence suggests CD8 or CD4 can enhance FcgammaR-dependent responses of human monocytes. Building on data that key components of TCR and FcgammaR signaling can substitute one another efficiently, we postulate that CD4 and CD8 operate with FcgammaR and potentially other receptors to enhance responses of T cells and various innate immune cells. Our model suggests CD8 on myeloid cells may contribute directly to tumor killing and tissue pathology by enhancing FcgammaR responses. Moreover, the model suggests a role for CD8 in cross-presentation of antibody-associated antigen by DCs and a new mechanism to regulate TCR sensitivity.
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Affiliation(s)
- Derrick Gibbings
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
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27
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Hematopoietic cell activation in the subventricular zone after Theiler's virus infection. J Neuroinflammation 2008; 5:44. [PMID: 18922161 PMCID: PMC2577640 DOI: 10.1186/1742-2094-5-44] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 10/15/2008] [Indexed: 02/04/2023] Open
Abstract
Background The periventricular subventricular zone (SVZ) contains stem cells and is an area of active neurogenesis and migration. Since inflammation can reduce neurogenesis, we tested whether Theiler's murine encephalomyelitis virus (TMEV) induces inflammation and reduces neurogenesis in the SVZ. Methods We performed immmunohistochemistry for the hematopoietic cell marker CD45 throughout the central nervous system and then examined neuroblasts in the SVZ. Results CD45+ activation (inflammation) occurred early in the forebrain and preceded cerebellar and spinal cord inflammation. Inflammation in the brain was regionally stochastic except for the SVZ and surrounding periventricular regions where it was remarkably pronounced and consistent. In preclinical mice, SVZ neuroblasts emigrated into inflamed periventricular regions. The number of proliferating phoshpohistone3+ cells and Doublecortin+ (Dcx) SVZ neuroblasts was overall unaffected during the periods of greatest inflammation. However the number of Dcx+ and polysialylated neural cell adhesion molecule (PSA-NCAM+) SVZ neuroblasts decreased only after periventricular inflammation abated. Conclusion Our results suggest that after TMEV infection, the SVZ may mount an attempt at neuronal repair via emigration, a process dampened by decreases in neuroblast numbers.
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Nikolic WV, Hou H, Town T, Zhu Y, Giunta B, Sanberg CD, Zeng J, Luo D, Ehrhart J, Mori T, Sanberg PR, Tan J. Peripherally administered human umbilical cord blood cells reduce parenchymal and vascular beta-amyloid deposits in Alzheimer mice. Stem Cells Dev 2008; 17:423-39. [PMID: 18366296 DOI: 10.1089/scd.2008.0018] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Modulation of immune/inflammatory responses by diverse strategies including amyloid-beta (Abeta) immunization, nonsteroidal anti-inflammatory drugs, and manipulation of microglial activation states has been shown to reduce Alzheimer's disease (AD)-like pathology and cognitive deficits in AD transgenic mouse models. Human umbilical cord blood cells (HUCBCs) have unique immunomodulatory potential. We wished to test whether these cells might alter AD-like pathology after infusion into the PSAPP mouse model of AD. Here, we report a marked reduction in Abeta levels/beta-amyloid plaques and associated astrocytosis following multiple low-dose infusions of HUCBCs. HUCBC infusions also reduced cerebral vascular Abeta deposits in the Tg2576 AD mouse model. Interestingly, these effects were associated with suppression of the CD40-CD40L interaction, as evidenced by decreased circulating and brain soluble CD40L (sCD40L), elevated systemic immunoglobulin M (IgM) levels, attenuated CD40L-induced inflammatory responses, and reduced surface expression of CD40 on microglia. Importantly, deficiency in CD40 abolishes the effect of HUCBCs on elevated plasma Abeta levels. Moreover, microglia isolated from HUCBC-infused PSAPP mice demonstrated increased phagocytosis of Abeta. Furthermore, sera from HUCBC-infused PSAPP mice significantly increased microglial phagocytosis of the Abeta1-42 peptide while inhibiting interferon-gammainduced microglial CD40 expression. Increased microglial phagocytic activity in this scenario was inhibited by addition of recombinant CD40L protein. These data suggest that HUCBC infusion mitigates AD-like pathology by disrupting CD40L activity.
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Affiliation(s)
- William V Nikolic
- Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry & Behavioral Medicine, University of South Florida, Tampa, FL 33613, USA
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Tsuda M, Ueno H, Kataoka A, Tozaki-Saitoh H, Inoue K. Activation of dorsal horn microglia contributes to diabetes-induced tactile allodynia via extracellular signal-regulated protein kinase signaling. Glia 2008; 56:378-86. [PMID: 18186080 DOI: 10.1002/glia.20623] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Painful neuropathy is one of the most common complications of diabetes, one hallmark of which is tactile allodynia (pain hypersensitivity to innocuous stimulation). The underlying mechanisms of tactile allodynia are, however, poorly understood. Emerging evidence indicates that, following nerve injury, activated microglia in the spinal cord play a crucial role in tactile allodynia. However, it remains unknown whether spinal microglia are activated under diabetic conditions and whether they contribute to diabetes-induced tactile allodynia. In the present study, using streptozotocin (STZ)-induced diabetic rats that displayed tactile allodynia, we found several morphological changes of activated microglia in the dorsal horn. These included increases in Iba1 and OX-42 labeling (markers of microglia), hypertrophic morphology, the thickness and the retraction of processes, and in the number of activated microglia cells. Furthermore, in the dorsal horn of STZ diabetic rats, extracellular signal-regulated protein kinase (ERK) and an upstream kinase, Src-family kinase (SFK), both of which are implicated in microglial functions, were activated exclusively in microglia. Moreover, inhibition of ERK phosphorylation in the dorsal horn by intrathecal administration of U0126, an inhibitor of ERK activation, produced a striking alleviation of existing, long-term tactile allodynia of diabetic rats. We also found that a single administration of U0126 reduced the expression of allodynia. Together, these results suggest that activated dorsal horn microglia may be a crucial component of diabetes-induced tactile allodynia, mediated, in part, by the ERK signaling pathway. Thus, inhibiting microglia activation in the dorsal horn may represent a therapeutic strategy for treating diabetic tactile allodynia.
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Affiliation(s)
- Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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Zhu Y, Hou H, Nikolic WV, Ehrhart J, Rrapo E, Bickford P, Giunta B, Tan J. CD45RB is a novel molecular therapeutic target to inhibit Abeta peptide-induced microglial MAPK activation. PLoS One 2008; 3:e2135. [PMID: 18478117 PMCID: PMC2366070 DOI: 10.1371/journal.pone.0002135] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Accepted: 03/27/2008] [Indexed: 12/28/2022] Open
Abstract
Background Microglial activation, characterized by p38 MAPK or p44/42 MAPK pathway signal transduction, occurs in Alzheimer's disease (AD). Our previous studies demonstrated CD45, a membrane-bound protein tyrosine phosphatase (PTP), opposed β-amyloid (Aβ) peptide-induced microglial activation via inhibition of p44/42 MAPK. Additionally we have shown agonism of the RB isoform of CD45 (CD45RB) abrogates lipopolysaccharide (LPS)-induced microglial activation. Methodology and Results In this study, CD45RB modulation of Aβ peptide or LPS-activated primary cultured microglial cells was further investigated. Microglial cells were co-treated with “aged” FITC-Aβ1–42 and multiple CD45 isoform agonist antibodies. Data revealed cross-linking of CD45, particularly the CD45RB isoform, enhances microglial phagocytosis of Aβ1–42 peptide and inhibits LPS-induced activation of p44/42 and p38 pathways. Co-treatment of microglial cells with agonist CD45 antibodies results in significant inhibition of LPS-induced microglial TNF-α and IL-6 release through p44/42 and/or p38 pathways. Moreover, inhibition of either of these pathways augmented CD45RB cross-linking induced microglial phagocytosis of Aβ1–42 peptide. To investigate the mechanism(s) involved, microglial cells were co-treated with a PTP inhibitor (potassium bisperoxo [1,10-phenanthroline oxovanadate; Phen]) and Aβ1–42 peptides. Data showed synergistic induction of microglial activation as evidenced by TNF-α and IL-6 release; both of which are demonstrated to be dependent on increased p44/42 and/or p38 activation. Finally, it was observed that cross-linking of CD45RB in the presence of Aβ1–42 peptide, inhibits co-localization of microglial MHC class II and Aβ peptide; suggesting CD45 activation inhibits the antigen presenting phenotype of microglial cells. Conclusion In summary, p38 MAPK is another novel signaling pathway, besides p44/42, in which CD45RB cross-linking negatively regulates microglial Aβ phagocytosis while increasing potentially neurotoxic inflammation. Therefore, agonism of CD45RB PTP activity may be an effective therapeutic target for novel agents to treat AD due to its Aβ lowering, and inflammation reducing, properties that are particularly targeted at microglial cells. Such treatments may be more effective with less potential to produce systemic side-effects than therapeutics which induce non-specific, systemic down-regulation of inflammation.
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Affiliation(s)
- Yuyan Zhu
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - Huayan Hou
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - William V. Nikolic
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - Jared Ehrhart
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - Elona Rrapo
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - Paula Bickford
- Center for Excellence in Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine, Tampa, Florida, United States of America
- Veterans Administration Hospital, Research Service, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - Brian Giunta
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
| | - Jun Tan
- Rashid Laboratory Developmental Neurobiology, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, Florida, United States of America
- Center for Excellence in Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine, Tampa, Florida, United States of America
- * E-mail:
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31
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Neuronal 'On' and 'Off' signals control microglia. Trends Neurosci 2007; 30:596-602. [PMID: 17950926 DOI: 10.1016/j.tins.2007.08.007] [Citation(s) in RCA: 550] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 07/18/2007] [Accepted: 08/03/2007] [Indexed: 11/24/2022]
Abstract
Recent findings indicate that neurons are not merely passive targets of microglia but rather control microglial activity. The variety of different signals that neurons use to control microglia can be divided into two categories: 'Off' signals constitutively keep microglia in their resting state and antagonize proinflammatory activity. 'On' signals are inducible and include purines, chemokines, glutamate. They instruct microglia activation under pathological conditions towards a beneficial or detrimental phenotype. Various neuronal signaling molecules thus actively control microglia function, thereby contribute to the inflammatory milieu of the central nervous system. Thus, neurons should be envisaged as key immune modulators in the brain.
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Obregon D, Hou H, Bai Y, Nikolic WV, Mori T, Luo D, Zeng J, Ehrhart J, Fernandez F, Morgan D, Giunta B, Town T, Tan J. CD40L disruption enhances Abeta vaccine-mediated reduction of cerebral amyloidosis while minimizing cerebral amyloid angiopathy and inflammation. Neurobiol Dis 2007; 29:336-53. [PMID: 18055209 DOI: 10.1016/j.nbd.2007.09.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 08/31/2007] [Accepted: 09/19/2007] [Indexed: 12/24/2022] Open
Abstract
Amyloid-beta (Abeta) immunization efficiently reduces amyloid plaque load and memory impairment in transgenic mouse models of Alzheimer's disease (AD). Active Abeta immunization has also yielded favorable results in a subset of AD patients. However, a small percentage of patients developed severe aseptic meningoencephalitis associated with brain inflammation and infiltration of T-cells. We have shown that blocking the CD40-CD40 ligand (L) interaction mitigates Abeta-induced inflammatory responses and enhances Abeta clearance. Here, we utilized genetic and pharmacologic approaches to test whether CD40-CD40L blockade could enhance the efficacy of Abeta(1-42) immunization, while limiting potentially damaging inflammatory responses. We show that genetic or pharmacologic interruption of the CD40-CD40L interaction enhanced Abeta(1-42) immunization efficacy to reduce cerebral amyloidosis in the PSAPP and Tg2576 mouse models of AD. Potentially deleterious pro-inflammatory immune responses, cerebral amyloid angiopathy (CAA) and cerebral microhemorrhage were reduced or absent in these combined approaches. Pharmacologic blockade of CD40L decreased T-cell neurotoxicity to Abeta-producing neurons. Further reduction of cerebral amyloidosis in Abeta-immunized PSAPP mice completely deficient for CD40 occurred in the absence of Abeta immunoglobulin G (IgG) antibodies or efflux of Abeta from brain to blood, but was rather correlated with anti-inflammatory cytokine profiles and reduced plasma soluble CD40L. These results suggest CD40-CD40L blockade promotes anti-inflammatory cellular immune responses, likely resulting in promotion of microglial phagocytic activity and Abeta clearance without generation of neurotoxic Abeta-reactive T-cells. Thus, combined approaches of Abeta immunotherapy and CD40-CD40L blockade may provide for a safer and more effective Abeta vaccine.
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Affiliation(s)
- D Obregon
- Neuroimmunology Laboratory, Institute for Research in Psychiatry, Department of Psychiatry and Behavioral Medicine, USA
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Shytle RD, Ehrhart J, Tan J, Vila J, Cole M, Sanberg CD, Sanberg PR, Bickford PC. Oxidative stress of neural, hematopoietic, and stem cells: protection by natural compounds. Rejuvenation Res 2007; 10:173-8. [PMID: 17518694 DOI: 10.1089/rej.2006.0515] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During natural aging, adult stem cells are known to have a reduced restorative capacity and are more vulnerable to oxidative stress resulting in a reduced ability of the body to heal itself. We report here that the proprietary natural product formulation, NT020, previously found to promote proliferation of human hematopoietic stem cells, reduced oxidative stress-induced apoptosis of murine neurons and microglial cells in vitro. Furthermore, when taken orally for 2 weeks, cultured bone marrow stem cells from these mice exhibited a dose-related reduction of oxidative stress-induced apoptosis. This preclinical study demonstrates that NT020 can act to promote healing via an interaction with stem cell populations and forms the basis of conducting a clinical trial to determine if NT020 exhibits similar health promoting effects in humans when used as a dietary supplement.
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Affiliation(s)
- R Douglas Shytle
- Department of Neurosurgery, Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, 12901 Bruce B. Downs Boulevard, Tampa, FL 33612, USA
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Irani DN, Prow NA. Neuroprotective interventions targeting detrimental host immune responses protect mice from fatal alphavirus encephalitis. J Neuropathol Exp Neurol 2007; 66:533-44. [PMID: 17549013 PMCID: PMC3143496 DOI: 10.1097/01.jnen.0000263867.46070.e2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Systemic treatment with the tetracycline derivative, minocycline, attenuates neurologic deficits in animal models of amyotrophic lateral sclerosis, hypoxic-ischemic brain injury, and multiple sclerosis. Inhibition of microglial activation within the CNS is 1 mechanism proposed to underlie the beneficial effects of the drug in these systems. Given the widening scope of acute viral encephalitis caused by mosquito-borne pathogens, we investigated the therapeutic effects of minocycline in a murine model of fatal alphavirus encephalomyelitis in which widespread microglial activation is known to occur. We found that minocycline conferred significant protection against both paralysis and death, even when started after viral challenge and despite having no effect on CNS virus replication or spread. Further studies demonstrated that minocycline inhibited early virus-induced microglial activation and that diminished CNS production of the inflammatory mediator, interleukin (IL)-1beta, contributed to its protective effect. Therapeutic blockade of IL-1 receptors also conferred significant protection in our model, validating the importance of the IL-1 pathway in disease pathogenesis. We propose that interventions targeting detrimental host immune responses arising from activated microglia may be of benefit in humans with acute viral encephalitis caused by related mosquito-borne pathogens. Such treatments could conceivably act through neuroprotective rather than antiviral mechanisms to generate these clinical effects.
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Affiliation(s)
- David N Irani
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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35
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Cosenza‐Nashat MA, Kim M, Zhao M, Suh H, Lee SC. CD45 isoform expression in microglia and inflammatory cells in HIV-1 encephalitis. Brain Pathol 2007; 16:256-65. [PMID: 17107594 PMCID: PMC1804203 DOI: 10.1111/j.1750-3639.2006.00027.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
CD45 is a membrane tyrosine phosphatase that modulates the function of the hematopoietic cells. In vitro, agonist antibodies to CD45RO or CD45RB isoforms have been shown to suppress microglial activation, but whether microglia in vivo express these isoforms in HIV encephalitis (HIVE) is unknown. Brain sections from control and HIVE were immunostained for CD45 isoforms using exon‐specific antibodies (RA, RB, RC and RO). RA and RC were limited to rare lymphocytes, while RB expression was robust in microglia and inflammatory cells. RO was low in control microglia, but increased in HIVE. RO was also localized to macrophages and CD8+ T cells. Targeting CD45 in vivo with isoform‐specific antibodies remains a therapeutic option for neuroinflammatory diseases.
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Affiliation(s)
| | - Mee‐Ohk Kim
- Department of Neurology, Massachusetts General Hospital, Boston, Mass
| | - Meng‐Liang Zhao
- Department of Pathology, Albert Einstein College of Medicine, Bronx, N.Y
| | - Hyeon‐Sook Suh
- Department of Pathology, Albert Einstein College of Medicine, Bronx, N.Y
| | - Sunhee C. Lee
- Department of Pathology, Albert Einstein College of Medicine, Bronx, N.Y
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36
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Kim MO, Suh HS, Si Q, Terman BI, Lee SC. Anti-CD45RO suppresses human immunodeficiency virus type 1 replication in microglia: role of Hck tyrosine kinase and implications for AIDS dementia. J Virol 2007; 80:62-72. [PMID: 16352531 PMCID: PMC1317521 DOI: 10.1128/jvi.80.1.62-72.2006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Macrophages and microglia are productively infected by HIV-1 and play a pivotal role in the pathogenesis of AIDS dementia. Although macrophages and microglia express CD45, a transmembrane protein tyrosine phosphatase, whether modulation of its activity affects human immunodeficiency virus type 1 (HIV-1) replication is unknown. Here, we report that of the five human CD45 isoforms, microglia express CD45RB and CD45RO (RB > RO) and treatment of microglia with a CD45 agonist antibody alphaCD45RO (UCHL-1) inhibits HIV-1 replication. alphaCD45RO prevented HIV-1 negative factor (Nef)-induced autophosphorylation of hematopoietic cell kinase (Hck), a myeloid lineage-specific Src kinase. Recombinant CD45 protein also inhibited HIV-1-induced Hck phosphorylation in microglia. Antennapedia-mediated delivery of Hck Src homology domain 3 (SH3), a domain that binds to the Nef PxxP motif with high affinity, reduced HIV-1-induced Hck phosphorylation and HIV-1 production in microglia. HIV-1-induced LTR transactivation was observed in U38 cells stably overexpressing wild-type Hck but not kinase-inactive Hck. In microglia, alphaCD45RO reduced activation of transcription factors (NF-kappaB and CCAAT enhancer binding protein) necessary for LTR transactivation in macrophages. These results establish that in myeloid lineage cells, Nef interacts with the Hck SH3 domain, resulting in autophosphorylation of Hck and an increase in HIV-1 transcription. alphaCD45RO-mediated inhibition of HIV-1 replication in microglia identifies the CD45 protein tyrosine phosphatase as a potential therapeutic target for HIV-1 infection/AIDS dementia.
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Affiliation(s)
- Mee-Ohk Kim
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA
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Tsuda M, Tozaki-Saitoh H, Masuda T, Toyomitsu E, Tezuka T, Yamamoto T, Inoue K. Lyn tyrosine kinase is required for P2X4 receptor upregulation and neuropathic pain after peripheral nerve injury. Glia 2007; 56:50-8. [DOI: 10.1002/glia.20591] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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38
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Goings GE, Kozlowski DA, Szele FG. Differential activation of microglia in neurogenic versus non-neurogenic regions of the forebrain. Glia 2006; 54:329-42. [PMID: 16862532 DOI: 10.1002/glia.20381] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Proliferation decreases in the neurogenic subventricular zone (SVZ) of mice after aspiration lesions of the cerebral cortex. We hypothesized that microglial activation may contribute to this given microglial activation attenuates neurogenesis in the hippocampus. Using CD45, CD11b, IB4, and IL-6 immunohistochemistry (IHC), BrdU IHC, and fluorescent bead tracking of peripheral monocytes into the brain, we compared microglial activation in the SVZ to non-neurogenic forebrain regions. SVZ microglia exhibited greater constitutive activation and proliferation than did microglia in non-neurogenic regions. In contrast to the SVZ, the dentate gyrus (DG) contained relatively few CD45(+) cells. After aspiration cerebral cortex lesions, microglia became activated in the cerebral cortex, corpus callosum, and striatum. SVZ microglial activation did not increase, and similarly, microglia in the DG were less activated after injury than in adjacent non-neurogenic regions. We next showed that SVZ microglia are not categorically refractory to activation, since deep cortical contusion injuries increased SVZ microglial activation. Macrophages migrate into the brain during development, but it is unclear if this is recapitulated after injury. Infiltration of microbead-labeled macrophages into the brain did not change after injury, but resident SVZ microglia were induced to migrate toward the injury. Our data show that both constitutive and postlesion levels of microglial activation differ between neurogenic and non-neurogenic regions.
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Affiliation(s)
- Gwendolyn E Goings
- Children's Memorial Research Center, Neurobiology Program, Children's Memorial Hospital, Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Hermiston ML, Tan AL, Gupta VA, Majeti R, Weiss A. The juxtamembrane wedge negatively regulates CD45 function in B cells. Immunity 2006; 23:635-47. [PMID: 16356861 DOI: 10.1016/j.immuni.2005.11.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Revised: 09/08/2005] [Accepted: 11/09/2005] [Indexed: 12/22/2022]
Abstract
CD45 is a receptor-like protein tyrosine phosphatase highly expressed on all nucleated hematopoietic cells. We previously generated mice containing a point mutation in the juxtamembrane wedge of CD45. Demonstrating the critical negative regulatory function of the wedge, the CD45 E613R mutation led to a lymphoproliferative disorder (LPD) and a lupus-like autoimmune syndrome. Here we show the central role of B cells in this phenotype. Genetic elimination of B cells, but not T cells, ablates the LPD. In contrast to CD45-deficient B cells, the E613R mutation generates hyperresponsive B cells. Comparison of CD45-deficient and CD45 E613R mice reveals dichotomous effects of these mutations on B cell development. Together, the results support a role for CD45 as a rheostat, with both positive and negative regulatory functions, that fine-tunes the signal transduction threshold at multiple checkpoints in B cell development.
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Affiliation(s)
- Michelle L Hermiston
- Department of Pediatrics, University of California, San Francisco, San Francisco, California 94143, USA
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40
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Kim YS, Kim SS, Cho JJ, Choi DH, Hwang O, Shin DH, Chun HS, Beal MF, Joh TH. Matrix metalloproteinase-3: a novel signaling proteinase from apoptotic neuronal cells that activates microglia. J Neurosci 2006; 25:3701-11. [PMID: 15814801 PMCID: PMC6725382 DOI: 10.1523/jneurosci.4346-04.2005] [Citation(s) in RCA: 202] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Microglial activation and inflammation are associated with progressive neuronal apoptosis in neurodegenerative human brain disorders. We sought to investigate molecular signaling mechanisms that govern activation of microglia in apoptotic neuronal degeneration. We report here that the active form of matrix metalloproteinase-3 (MMP-3) was released into the serum-deprived media (SDM) of PC12 cells and other media of apoptotic neuronal cells within 2-6 h of treatment of the cells, and SDM and catalytic domain of recombinant MMP-3 (cMMP-3) activated microglia in primary microglia cultures as well as BV2 cells, a mouse microglia cell line. Both SDM and cMMP-3 induced generation of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), IL-1beta, and interleukin-1 receptor antagonist but not IL-12 and inducible nitric oxide synthase, which are readily induced by lipopolysaccharide, in microglia, suggesting that there is a characteristic pattern of microglial cytokine induction by apoptotic neurons. Neither glial cell line-derived neurotrophic factor nor anti-inflammatory cytokines, such as IL-10 and transforming growth factor-beta1, were induced. SDM and cMMP-3 extensively released TNF-alpha from microglia and activated the nuclear factor-kappaB pathway, and these microglial responses were totally abolished by preincubation with an MMP-3 inhibitor, NNGH [N-isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid]. MMP-3-mediated microglial activation mostly depended on ERK (extracellular signal-regulated kinase) phosphorylation but not much on either JNK (c-Jun N-terminal protein kinase) or p38 activation. Conditioned medium of SDM- or cMMP-3-activated BV2 cells caused apoptosis of PC12 cells. These results strongly suggest that the distinctive signal of neuronal apoptosis is the release of active form of MMP-3 that activates microglia and subsequently exacerbates neuronal degeneration. Therefore, the release of MMP-3 from apoptotic neurons may play a major role in degenerative human brain disorders, such as Parkinson's disease.
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Affiliation(s)
- Yoon Seong Kim
- Burke Medical Research Institute, Weill Medical College and Graduate School of Medical Sciences of Cornell University, White Plains, New York 10605, USA
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41
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Ehrhart J, Obregon D, Mori T, Hou H, Sun N, Bai Y, Klein T, Fernandez F, Tan J, Shytle RD. Stimulation of cannabinoid receptor 2 (CB2) suppresses microglial activation. J Neuroinflammation 2005; 2:29. [PMID: 16343349 PMCID: PMC1352348 DOI: 10.1186/1742-2094-2-29] [Citation(s) in RCA: 260] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2005] [Accepted: 12/12/2005] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Activated microglial cells have been implicated in a number of neurodegenerative disorders, including Alzheimer's disease (AD), multiple sclerosis (MS), and HIV dementia. It is well known that inflammatory mediators such as nitric oxide (NO), cytokines, and chemokines play an important role in microglial cell-associated neuron cell damage. Our previous studies have shown that CD40 signaling is involved in pathological activation of microglial cells. Many data reveal that cannabinoids mediate suppression of inflammation in vitro and in vivo through stimulation of cannabinoid receptor 2 (CB2). METHODS In this study, we investigated the effects of a cannabinoid agonist on CD40 expression and function by cultured microglial cells activated by IFN-gamma using RT-PCR, Western immunoblotting, flow cytometry, and anti-CB2 small interfering RNA (siRNA) analyses. Furthermore, we examined if the stimulation of CB2 could modulate the capacity of microglial cells to phagocytise Abeta1-42 peptide using a phagocytosis assay. RESULTS We found that the selective stimulation of cannabinoid receptor CB2 by JWH-015 suppressed IFN-gamma-induced CD40 expression. In addition, this CB2 agonist markedly inhibited IFN-gamma-induced phosphorylation of JAK/STAT1. Further, this stimulation was also able to suppress microglial TNF-alpha and nitric oxide production induced either by IFN-gamma or Abeta peptide challenge in the presence of CD40 ligation. Finally, we showed that CB2 activation by JWH-015 markedly attenuated CD40-mediated inhibition of microglial phagocytosis of Abeta1-42 peptide. Taken together, these results provide mechanistic insight into beneficial effects provided by cannabinoid receptor CB2 modulation in neurodegenerative diseases, particularly AD.
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Affiliation(s)
- Jared Ehrhart
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - Demian Obregon
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - Takashi Mori
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Institute of Medical Science, Saitama Medical School, Saitama 350-8550, Japan
| | - Huayan Hou
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - Nan Sun
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - Yun Bai
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Department of Molecular Genetics, the Third Medical University, Chongqing, China
| | - Thomas Klein
- Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - Francisco Fernandez
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - Jun Tan
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Center for Excellence in Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Department of Pharmacology and Therapeutics, University of South Florida College of Medicine, Tampa, FL 33613, USA
| | - R Douglas Shytle
- Neuroimmunlogy Laboratory, Silver Child Development Center, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Center for Excellence in Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine, Tampa, FL 33613, USA
- Department of Pharmacology and Therapeutics, University of South Florida College of Medicine, Tampa, FL 33613, USA
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42
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De Dios I, Ramudo L, Alonso JR, Recio JS, Garcia-Montero AC, Manso MA. CD45 expression on rat acinar cells: Involvement in pro-inflammatory cytokine production. FEBS Lett 2005; 579:6355-60. [PMID: 16263122 DOI: 10.1016/j.febslet.2005.10.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Revised: 10/06/2005] [Accepted: 10/12/2005] [Indexed: 11/20/2022]
Abstract
CD45 transduces activation signals in inflammatory cells. We investigate CD45 expression on pancreatic acinar cells and examine its role in the inflammatory response which these cells have also shown under certain circumstances. Similar CD45 mRNA levels were found in acinar cells and leukocytes (positive control). Flow cytometric and immunohistochemical analysis showed a heterogeneous CD45 distribution on acinar cells. Activation of acinar cells by incubation with pancreatitis-associated ascitic fluid as evidencied by TNF-alpha production resulted in a decreased CD45 expression, suggesting that CD45 acts as a negative regulator of cytokine production. As a validation of this finding in vivo, a decrease in the acinar CD45 expression in parallel with an increased ability to produce TNF-alpha was found in rats with acute pancreatitis. Our data show that CD45 is constitutively expressed in acinar cells and suggest that it plays an important role in negatively regulating cytokine production.
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Affiliation(s)
- Isabel De Dios
- Department of Physiology and Pharmacology, University of Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007 Salamanca, Spain.
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43
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Suh HS, Kim MO, Lee SC. Inhibition of granulocyte-macrophage colony-stimulating factor signaling and microglial proliferation by anti-CD45RO: role of Hck tyrosine kinase and phosphatidylinositol 3-kinase/Akt. THE JOURNAL OF IMMUNOLOGY 2005; 174:2712-9. [PMID: 15728479 DOI: 10.4049/jimmunol.174.5.2712] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Increasing evidence suggests that CD45, a transmembrane protein tyrosine phosphatase, is an important modulator of macrophage activation. Microglia, resident brain macrophages, express CD45 and proliferate under pathologic conditions. In this study, we examined the role of CD45 in modulating GM-CSF-induced proliferation and signal transduction in primary human microglial cultures. Soluble, but not immobilized anti-CD45RO induced tyrosine phosphatase activity and inhibited GM-CSF-induced microglial proliferation. Microglial proliferation was also inhibited by PP2 (Src inhibitor), LY294002 (PI3K inhibitor), and U0126 (MEK inhibitor). GM-CSF induced phosphorylation of Jak2, Stat5, Hck (the myeloid-restricted Src kinase), Akt, Stat3, and Erk MAPKs in microglia. Of these, anti-CD45RO inhibited phosphorylation of Hck and Akt, and PP2 inhibited phosphorylation of Hck and Akt. In a macrophage cell line stably overexpressing wild-type or kinase-inactive Hck, GM-CSF increased proliferation of the control (empty vector) and wild-type but not kinase-inactive cells, and this was inhibited by anti-CD45RO. Together, these results demonstrate that, in macrophages, Hck tyrosine kinase is activated by GM-CSF, and that Hck plays a pivotal role in cell proliferation and survival by activating the PI3K/Akt pathway. Ab-mediated activation of macrophage and microglial CD45 tyrosine phosphatase may have therapeutic implications for CNS inflammatory diseases.
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Affiliation(s)
- Hyeon-Sook Suh
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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44
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Townsend KP, Town T, Mori T, Lue LF, Shytle D, Sanberg PR, Morgan D, Fernandez F, Flavell RA, Tan J. CD40 signaling regulates innate and adaptive activation of microglia in response to amyloid beta-peptide. Eur J Immunol 2005; 35:901-10. [PMID: 15688347 DOI: 10.1002/eji.200425585] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although deposition of amyloid beta-peptide (Abeta) as Abeta plaques involves activation of microglia-mediated inflammatory responses, activated microglia ultimately fail to clear Abeta plaques in the brains of either Alzheimer's disease (AD) patients or AD mouse models. Mounting evidence suggests that chronic microglia-mediated immune response during Abeta deposition etiologically contributes to AD pathogenesis by promoting Abeta plaque formation. However, the mechanisms that govern microglia response in the context of cerebral Abeta/beta-amyloid pathology are not well understood. We show that ligation of CD40 by CD40L modulates Abeta-induced innate immune responses in microglia, including decreased microglia phagocytosis of exogenous Abeta(1-42) and increased production of pro-inflammatory cytokines. CD40 ligation in the presence of Abeta(1-42) leads to adaptive activation of microglia, as evidenced by increased co-localization of MHC class II with Abeta. To assess their antigen-presenting cell (APC) function, cultured microglia were pulsed with Abeta(1-42) in the presence of CD40L and co-cultured with CD4(+) T cells. Under these conditions, microglia stimulate T cell-derived IFN-gamma and IL-2 production, suggesting that CD40 signaling promotes the APC phenotype. These data provide a mechanistic explanation for our previous work showing decreased microgliosis associated with diminished cerebral Abeta/beta-amyloid pathology when blocking CD40 signaling in transgenic Alzheimer's mice.
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Affiliation(s)
- Kirk P Townsend
- Neuroimmunology Laboratory, Department of Psychiatry, University of South Florida College of Medicine, Tampa, USA
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45
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Chen Z, Duan RS, Quezada HC, Mix E, Nennesmo I, Adem A, Winblad B, Zhu J. Increased microglial activation and astrogliosis after intranasal administration of kainic acid in C57BL/6 mice. ACTA ACUST UNITED AC 2005; 62:207-18. [PMID: 15459893 DOI: 10.1002/neu.20099] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Glutamate excitotoxicity plays a key role in inducing neuronal cell death in many neurological diseases. In mice, intranasal administration of kainic acid (KA), an analogue of the excitotoxin glutamate, results in hippocampal cell death and provides a well-characterized model for studies of human neurodegenerative diseases. In this study, we describe neurodegeneration and gliosis following intranasal administration of KA in C57BL/6 mice. By using Nissl's staining, neurodegeneration was found in area CA3 of hippocampus, and neuronal apoptosis was demonstrated by enhanced FAS(CD95/APO-1) expression detected by immunohistochemistry and Western blotting. Astrogliosis was exhibited by increased glial fibrillary acidic protein (GFAP) expression in the hippocampus and cortex. We also studied the profile of molecular expression on microglia in C57BL/6 mice. One and 3 days after KA administration, CD45, F4/80, CD86, MHCII, iNOS but not CD40 expression was enhanced or induced on microglia. In summary, KA administration results in an early microglial activation and a prolonged astrogliosis in C57BL/6 mice.
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Affiliation(s)
- Zhiguo Chen
- Division of Experimental Geriatrics, Department of Neurotec, Karolinska Institute, Karolinska University Hospital, Stockholm 14186, Sweden.
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46
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Carson MJ, Thrash JC, Lo D. Analysis of microglial gene expression: identifying targets for CNS neurodegenerative and autoimmune disease. ACTA ACUST UNITED AC 2004; 4:321-30. [PMID: 15462610 DOI: 10.2165/00129785-200404050-00005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Microglia are the tissue macrophage of the central nervous system (CNS) and their activation is among the earliest signs of CNS dysfunction and disease. Because microglia express many macrophage markers, they are presumed to act primarily as effectors of CNS inflammation and destruction. While such responses are beneficial to the extent that they destroy CNS pathogens, these responses do have the potential to have neurotoxic outcomes. Consequently, therapies for many CNS neurodegenerative and inflammatory diseases have been directed at suppressing microglial function. There is evidence to suggest that microglia play an important role during CNS development and maintenance of CNS function that may go beyond simple defense against pathogens. Molecular analysis of microglial phenotypes and function has revealed three striking findings: (i) that microglia are a unique CNS-specific type of tissue macrophage; (ii) that they are highly heterogeneous within the healthy CNS; and (iii) that microglial responses are exquisitely tailored to specific regions of the CNS and specific pathological insults. We suggest that ubiquitous suppression (rather than targeted manipulation) of microglial function may fail to fully ameliorate CNS pathology and may even ultimately promote maladaptive outcomes.
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Affiliation(s)
- Monica J Carson
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California, USA.
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Chen Z, Duan RS, Concha QH, Wu Q, Mix E, Winblad B, Ljunggren HG, Zhu J. IL-12p35 deficiency alleviates kainic acid-induced hippocampal neurodegeneration in C57BL/6 mice. Neurobiol Dis 2004; 17:171-8. [PMID: 15474355 DOI: 10.1016/j.nbd.2004.07.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Revised: 06/23/2004] [Accepted: 07/30/2004] [Indexed: 11/29/2022] Open
Abstract
The role of IL-12 in excitotoxic neurodegeneration of brain is largely unknown. To address this issue, we used the model of kainic acid (KA)-induced hippocampal injury in IL-12p35 knockout (KO) mice, a well-characterized model for human neurodegenerative diseases. After KA treatment, hippocampal neurodegeneration was significantly less severe in the IL-12p35 KO mice than in wild-type mice as demonstrated by reduced pathological changes and astrogliosis. One day after KA treatment, levels of F4/80 and CD86 expression on microglia were significantly lower in IL-12p35 KO mice than in wild-type mice analyzed by flow cytometry, indicating that IL-12p35 deficiency resulted in lower levels of microglial activation. Five days after KA treatment, CD86 expression on microglia of wild-type mice was still higher, whereas F4/80 expression in wild-type mice decreased and was similar to that in IL-12p35 KO mice. Because microglial activation is necessary for KA-induced neurodegeneration, the lower level of microglial activation in the absence of IL-12p35 may alleviate hippocampal injury in KO mice. In summary, this study indicates that IL-12 may play a critical role in excitotoxin-induced brain injury.
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Affiliation(s)
- Zhiguo Chen
- Division of Experimental Geriatrics, Department of Neurotec, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden
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Giunta B, Ehrhart J, Townsend K, Sun N, Vendrame M, Shytle D, Tan J, Fernandez F. Galantamine and nicotine have a synergistic effect on inhibition of microglial activation induced by HIV-1 gp120. Brain Res Bull 2004; 64:165-70. [PMID: 15342104 DOI: 10.1016/j.brainresbull.2004.06.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2004] [Revised: 06/03/2004] [Accepted: 06/09/2004] [Indexed: 11/29/2022]
Abstract
Chronic brain inflammation is the common final pathway in the majority of neurodegenerative diseases and central to this phenomenon is the immunological activation of brain mononuclear phagocyte cells, called microglia. This inflammatory mechanism is a central component of HIV-associated dementia (HAD). In the healthy state, there are endogenous signals from neurons and astrocytes, which limit excessive central nervous system (CNS) inflammation. However, the signals controlling this process have not been fully elucidated. Studies on the peripheral nervous system suggest that a cholinergic anti-inflammatory pathway regulates systemic inflammatory response by way of acetylcholine acting at the alpha7 nicotinic acetylcholine receptor (alpha7nAChR) found on blood-borne macrophages. Recent data from our laboratory indicates that cultured microglial cells also express this same receptor and that microglial anti-inflammatory properties are mediated through it and the p44/42 mitogen-activated protein kinase (MAPK) system. Here we report for the first time the creation of an in vitro model of HAD composed of cultured microglial cells synergistically activated by the addition of IFN-gamma and the HIV-1 coat glycoprotein, gp120. Furthermore, this activation, as measured by TNF-alpha and nitric oxide (NO) release, is synergistically attenuated through the alpha7 nAChR and p44/42 MAPK system by pretreatment with nicotine, and the cholinesterase inhibitor, galantamine. Our findings suggest a novel therapeutic combination to treat or prevent the onset of HAD through this modulation of the microglia inflammatory mechanism.
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Affiliation(s)
- B Giunta
- Neuroimmunology Laboratory, College of Medicine, University of South Florida, 3515 E. Fletcher Avenue, Tampa, FL 33613, USA
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49
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Shytle RD, Mori T, Townsend K, Vendrame M, Sun N, Zeng J, Ehrhart J, Silver AA, Sanberg PR, Tan J. Cholinergic modulation of microglial activation by alpha 7 nicotinic receptors. J Neurochem 2004; 89:337-43. [PMID: 15056277 DOI: 10.1046/j.1471-4159.2004.02347.x] [Citation(s) in RCA: 447] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Almost all degenerative diseases of the CNS are associated with chronic inflammation. A central step in this process is the activation of brain mononuclear phagocyte cells, called microglia. While it is recognized that healthy neurons and astrocytes regulate the magnitude of microglia-mediated innate immune responses and limit excessive CNS inflammation, the endogenous signals governing this process are not fully understood. In the peripheral nervous system, recent studies suggest that an endogenous 'cholinergic anti-inflammatory pathway' regulates systemic inflammatory responses via alpha 7 nicotinic acetylcholinergic receptors (nAChR) found on blood-borne macrophages. These data led us to investigate whether a similar cholinergic pathway exists in the brain that could regulate microglial activation. Here we report for the first time that cultured microglial cells express alpha 7 nAChR subunit as determined by RT-PCR, western blot, immunofluorescent, and immunohistochemistry analyses. Acetylcholine and nicotine pre-treatment inhibit lipopolysaccharide (LPS)-induced TNF-alpha release in murine-derived microglial cells, an effect attenuated by alpha 7 selective nicotinic antagonist, alpha-bungarotoxin. Furthermore, this inhibition appears to be mediated by a reduction in phosphorylation of p44/42 and p38 mitogen-activated protein kinase (MAPK). Though preliminary, our findings suggest the existence of a brain cholinergic pathway that regulates microglial activation through alpha 7 nicotinic receptors. Negative regulation of microglia activation may also represent additional mechanism underlying nicotine's reported neuroprotective properties.
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Affiliation(s)
- R Douglas Shytle
- Child Development Center, Neuroimmunology Laboratory, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medciine, Tampa, Florida, USA
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50
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Townsend KP, Vendrame M, Ehrhart J, Faza B, Zeng J, Town T, Tan J. CD45 isoform RB as a molecular target to oppose lipopolysaccharide-induced microglial activation in mice. Neurosci Lett 2004; 362:26-30. [PMID: 15147773 DOI: 10.1016/j.neulet.2004.01.082] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Accepted: 01/29/2004] [Indexed: 11/16/2022]
Abstract
CD45 is a membrane-bound protein tyrosine phosphatase expressed on all hemopoietic cells with multiple splice variants, including RA, RB, RC and RO. Our previous studies have shown that cross-linking of CD45 with an anti-CD45 antibody markedly inhibits LPS-induced microglia activation. In order to determine which of the CD45 isoforms may be responsible for these effects, we have investigated the expression of CD45 isoforms on cultured microglial cells using flow cytometric analysis. Data reveal that CD45RB is the predominant isoform expressed in murine primary cultured microglial cells. Furthermore, incubation of these cultured cells with anti-CD45RB antibody results in a reduction of microglial activation induced by LPS as evidenced by TNF-alpha production. As a validation of these findings in vivo, brain homogenates from anti-CD45RB antibody (MG23G2)-injected animals that had been treated with LPS demonstrate a significant decrease in TNF-alpha levels compared to control mice treated with LPS plus vehicle. Taken together, these findings suggest that therapeutic agents that specifically stimulate the microglial CD45RB signaling pathway may be effective in suppressing microglial activation associated with several neurodegenerative disorders.
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Affiliation(s)
- Kirk P Townsend
- Neuroimmunology Laboratory, Institute for Psychiatry in Research, Department of Psychiatry and Behavioral Medicine, University of South Florida College of Medicine, 3515 East Fletcher Avenue, Tampa, FL 33613, USA
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