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Somelar-Duracz K, Jürgenson M, Viil J, Zharkovsky A, Jaako K. 'Unpredictable chronic mild stress does not exacerbate memory impairment or altered neuronal and glial plasticity in the hippocampus of middle-aged vitamin D deficient mice'. Eur J Neurosci 2024; 59:1696-1722. [PMID: 38269959 DOI: 10.1111/ejn.16256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 12/10/2023] [Accepted: 01/02/2024] [Indexed: 01/26/2024]
Abstract
Vitamin D deficiency is a worldwide health concern, especially in the elderly population. Much remains unknown about the relationship between vitamin D deficiency (VDD), stress-induced cognitive dysfunctions and depressive-like behaviour. In this study, 4-month-old male C57Bl/6J mice were fed with control or vitamin D free diet for 6 months, followed by unpredictable chronic stress (UCMS) for 8 weeks. VDD induced cognitive impairment and reduced grooming behaviour, but did not induce depressive-like behaviour. While UCMS in vitamin D sufficient mice induced expected depressive-like phenotype and impairments in the contextual fear memory, chronic stress did not manifest as an additional risk factor for memory impairments and depressive-like behaviour in VDD mice. In fact, UCMS restored self-care behaviour in VDD mice. At the histopathological level, VDD mice exhibited cell loss in the granule cell layer, reduced survival of newly generated cells, accompanied with an increased number of apoptotic cells and alterations in glial morphology in the hippocampus; however, these effects were not exacerbated by UCMS. Interestingly, UCMS reversed VDD induced loss of microglial cells. Moreover, tyrosine hydroxylase levels decreased in the striatum of VDD mice, but not in stressed VDD mice. These findings indicate that long-term VDD in adulthood impairs cognition but does not augment behavioural response to UCMS in middle-aged mice. While VDD caused cell loss and altered glial response in the DG of the hippocampus, these effects were not exacerbated by UCMS and could contribute to mechanisms regulating altered stress response.
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Affiliation(s)
- Kelli Somelar-Duracz
- Institute of Biomedicine and Translational Medicine, Department of Pharmacology, University of Tartu, Tartu, Estonia
| | - Monika Jürgenson
- Institute of Biomedicine and Translational Medicine, Department of Pharmacology, University of Tartu, Tartu, Estonia
| | - Janeli Viil
- Institute of Biomedicine and Translational Medicine, Department of Pharmacology, University of Tartu, Tartu, Estonia
| | - Alexander Zharkovsky
- Institute of Biomedicine and Translational Medicine, Department of Pharmacology, University of Tartu, Tartu, Estonia
| | - Külli Jaako
- Institute of Biomedicine and Translational Medicine, Department of Pharmacology, University of Tartu, Tartu, Estonia
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2
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Stonedahl S, Leser JS, Clarke P, Potter H, Boyd TD, Tyler KL. Treatment with Granulocyte-Macrophage Colony-Stimulating Factor Reduces Viral Titers in the Brains of West Nile Virus-Infected Mice and Improves Survival. J Virol 2023; 97:e0180522. [PMID: 36802227 PMCID: PMC10062152 DOI: 10.1128/jvi.01805-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/29/2023] [Indexed: 02/23/2023] Open
Abstract
West Nile virus (WNV) is the leading cause of epidemic arboviral encephalitis in the United States. As there are currently no proven antiviral therapies or licensed human vaccines, understanding the neuropathogenesis of WNV is critical for rational therapeutic design. In WNV-infected mice, the depletion of microglia leads to enhanced viral replication, increased central nervous system (CNS) tissue injury, and increased mortality, suggesting that microglia play a critical role in protection against WNV neuroinvasive disease. To determine if augmenting microglial activation would provide a potential therapeutic strategy, we administered granulocyte-macrophage colony-stimulating factor (GM-CSF) to WNV-infected mice. Recombinant human GM-CSF (rHuGMCSF) (sargramostim [Leukine]) is an FDA-approved drug used to increase white blood cells following leukopenia-inducing chemotherapy or bone marrow transplantation. Daily treatment of both uninfected and WNV-infected mice with subcutaneous injections of GM-CSF resulted in microglial proliferation and activation as indicated by the enhanced expression of the microglia activation marker ionized calcium binding adaptor molecule 1 (Iba1) and several microglia-associated inflammatory cytokines, including CCL2 (C-C motif chemokine ligand 2), interleukin 6 (IL-6), and IL-10. In addition, more microglia adopted an activated morphology as demonstrated by increased sizes and more pronounced processes. GM-CSF-induced microglial activation in WNV-infected mice was associated with reduced viral titers and apoptotic activity (caspase 3) in the brains of WNV-infected mice and significantly increased survival. WNV-infected ex vivo brain slice cultures (BSCs) treated with GM-CSF also showed reduced viral titers and caspase 3 apoptotic cell death, indicating that GM-CSF specifically targets the CNS and that its actions are not dependent on peripheral immune activity. Our studies suggest that stimulation of microglial activation may be a viable therapeutic approach for the treatment of WNV neuroinvasive disease. IMPORTANCE Although rare, WNV encephalitis poses a devastating health concern, with few treatment options and frequent long-term neurological sequelae. Currently, there are no human vaccines or specific antivirals against WNV infections, so further research into potential new therapeutic agents is critical. This study presents a novel treatment option for WNV infections using GM-CSF and lays the foundation for further studies into the use of GM-CSF as a treatment for WNV encephalitis as well as a potential treatment for other viral infections.
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Affiliation(s)
- Sarah Stonedahl
- Department of Immunology, University of Colorado, Aurora, Colorado, USA
- Department of Microbiology, University of Colorado, Aurora, Colorado, USA
| | - J. Smith Leser
- Department of Neurology, University of Colorado, Aurora, Colorado, USA
| | - Penny Clarke
- Department of Neurology, University of Colorado, Aurora, Colorado, USA
| | - Huntington Potter
- Department of Neurology, University of Colorado, Aurora, Colorado, USA
- University of Colorado Alzheimer’s and Cognition Center, Aurora, Colorado, USA
- Linda Crnic Institute for Down Syndrome, Aurora, Colorado, USA
| | - Timothy D. Boyd
- University of Colorado Alzheimer’s and Cognition Center, Aurora, Colorado, USA
- Linda Crnic Institute for Down Syndrome, Aurora, Colorado, USA
| | - Kenneth L. Tyler
- Department of Neurology, University of Colorado, Aurora, Colorado, USA
- Division of Infectious Disease, Department of Medicine, University of Colorado, Aurora, Colorado, USA
- Denver VA Medical Center, Aurora, Colorado, USA
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3
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Sargeant TJ, Fourrier C. Human monocyte-derived microglia-like cell models: A review of the benefits, limitations and recommendations. Brain Behav Immun 2023; 107:98-109. [PMID: 36202170 DOI: 10.1016/j.bbi.2022.09.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 09/09/2022] [Accepted: 09/30/2022] [Indexed: 11/05/2022] Open
Abstract
In the last few decades, mounting evidence has highlighted that microglia have crucial roles in both health and disease. This has led to a growing interest in studying human microglia in disease-relevant models. However, current models present limitations that can make them unsuitable for moderate throughput studies in human cohorts. Primary human microglia are ethically and technically difficult to obtain and only allow low throughput studies; immortalized cell lines have been shown to differ too greatly from primary human microglia; and induced pluripotent stem cell-derived microglia, although physiologically relevant in most contexts, have limited potential for use in large cohorts of people or for personalised drug screening. In this review, we discuss monocyte-derived microglia-like (MDMi) cells, a model that has been developed and increasingly used in the last decade, using human monocytes isolated from blood samples. We describe the variety of protocols that have been used to develop MDMi cell models and highlight a need for standardization across protocols. We then summarize data that validate MDMi cells as an appropriate model to study human microglia in health and disease. We also present the benefits and limitations of using this approach to study human microglia compared with other microglial models, when used in combination with the relevant downstream applications and with cross-validation of findings in other systems. Finally, we summarize the paradigms in which MDMi models have been used to advance research on microglia in immune-related disease. This review is an important reference for scientists who seek to establish MDMi cells as a microglial model for the advancement of our understanding of microglia in human health and disease.
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Affiliation(s)
- Timothy J Sargeant
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, South Australia, Australia.
| | - Célia Fourrier
- Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide, South Australia, Australia; Adelaide Medical School, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
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4
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Bartolo ND, Mortimer N, Manter MA, Sanchez N, Riley M, O'Malley TT, Hooker JM. Identification and Prioritization of PET Neuroimaging Targets for Microglial Phenotypes Associated with Microglial Activity in Alzheimer's Disease. ACS Chem Neurosci 2022; 13:3641-3660. [PMID: 36473177 DOI: 10.1021/acschemneuro.2c00607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Activation of microglial cells accompanies the progression of many neurodegenerative disorders, including Alzheimer's disease (AD). Development of molecular imaging tools specific to microglia can help elucidate the mechanism through which microglia contribute to the pathogenesis and progression of neurodegenerative disorders. Through analysis of published genetic, transcriptomic, and proteomic data sets, we identified 19 genes with microglia-specific expression that we then ranked based on association with the AD characteristics, change in expression, and potential druggability of the target. We believe that the process we used to identify and rank microglia-specific genes is broadly applicable to the identification and evaluation of targets in other disease areas and for applications beyond molecular imaging.
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Affiliation(s)
- Nicole D Bartolo
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Niall Mortimer
- Human Biology and Data Science, Eisai Center for Genetics Guided Dementia Discovery, 35 Cambridgepark Drive, Cambridge, Massachusetts 02140, United States
| | - Mariah A Manter
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Nicholas Sanchez
- Human Biology and Data Science, Eisai Center for Genetics Guided Dementia Discovery, 35 Cambridgepark Drive, Cambridge, Massachusetts 02140, United States
| | - Misha Riley
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Tiernan T O'Malley
- Human Biology and Data Science, Eisai Center for Genetics Guided Dementia Discovery, 35 Cambridgepark Drive, Cambridge, Massachusetts 02140, United States
| | - Jacob M Hooker
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 13th Street, Charlestown, Massachusetts 02129, United States
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Ferrari LF, Rey C, Ramirez A, Dziuba A, Zickella J, Zickella M, Raff H, Taylor NE. Characterization of the Dahl salt-sensitive rat as a rodent model of inherited, widespread, persistent pain. Sci Rep 2022; 12:19348. [PMID: 36369350 PMCID: PMC9652451 DOI: 10.1038/s41598-022-24094-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022] Open
Abstract
Animal models are essential for studying the pathophysiology of chronic pain disorders and as screening tools for new therapies. However, most models available do not reproduce key characteristics of clinical persistent pain. This has limited their ability to accurately predict which new medicines will be clinically effective. Here, we characterize the Dahl salt-sensitive (SS) rat strain as the first rodent model of inherited widespread hyperalgesia. We show that this strain exhibits physiological phenotypes known to contribute to chronic pain, such as neuroinflammation, defective endogenous pain modulation, dysfunctional hypothalamic-pituitary-adrenal axis, increased oxidative stress and immune cell activation. When compared with Sprague Dawley and Brown Norway rats, SS rats have lower nociceptive thresholds due to increased inflammatory mediator concentrations, lower corticosterone levels, and high oxidative stress. Treatment with dexamethasone, the reactive oxygen species scavenger tempol, or the glial inhibitor minocycline attenuated the pain sensitivity in SS rats without affecting the other strains while indomethacin and gabapentin provided less robust pain relief. Moreover, SS rats presented impaired diffuse noxious inhibitory controls and an exacerbated response to the proalgesic mediator PGE2, features of generalized pain conditions. These data establish this strain as a novel model of spontaneous, widespread hyperalgesia that can be used to identify biomarkers for chronic pain diagnosis and treatment.
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Affiliation(s)
- Luiz F. Ferrari
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
| | - Charles Rey
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
| | - Anna Ramirez
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
| | - Adam Dziuba
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
| | - Jacqueline Zickella
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
| | - Michael Zickella
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
| | - Hershel Raff
- grid.427152.7Endocrine Research Laboratory, Aurora St. Luke’s Medical Center, Advocate Aurora Research Institute, Milwaukee, WI 53215 USA ,grid.30760.320000 0001 2111 8460Department of Medicine (Endocrinology and Molecular Medicine), Medical College of Wisconsin, Milwaukee, WI 53226 USA
| | - Norman E. Taylor
- grid.223827.e0000 0001 2193 0096Department of Anesthesiology, University of Utah School of Medicine, 383 Colorow Drive, Salt Lake City, UT 84108 USA
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6
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Events Occurring in the Axotomized Facial Nucleus. Cells 2022; 11:cells11132068. [PMID: 35805151 PMCID: PMC9266054 DOI: 10.3390/cells11132068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/26/2022] [Accepted: 06/27/2022] [Indexed: 01/27/2023] Open
Abstract
Transection of the rat facial nerve leads to a variety of alterations not only in motoneurons, but also in glial cells and inhibitory neurons in the ipsilateral facial nucleus. In injured motoneurons, the levels of energy metabolism-related molecules are elevated, while those of neurofunction-related molecules are decreased. In tandem with these motoneuron changes, microglia are activated and start to proliferate around injured motoneurons, and astrocytes become activated for a long period without mitosis. Inhibitory GABAergic neurons reduce the levels of neurofunction-related molecules. These facts indicate that injured motoneurons somehow closely interact with glial cells and inhibitory neurons. At the same time, these events allow us to predict the occurrence of tissue remodeling in the axotomized facial nucleus. This review summarizes the events occurring in the axotomized facial nucleus and the cellular and molecular mechanisms associated with each event.
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Dikmen HO, Hemmerich M, Lewen A, Hollnagel JO, Chausse B, Kann O. GM-CSF induces noninflammatory proliferation of microglia and disturbs electrical neuronal network rhythms in situ. J Neuroinflammation 2020; 17:235. [PMID: 32782006 PMCID: PMC7418331 DOI: 10.1186/s12974-020-01903-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/16/2020] [Indexed: 12/19/2022] Open
Abstract
Background The granulocyte-macrophage colony-stimulating factor (GM-CSF) (or CSF-2) is involved in myeloid cell growth and differentiation, and, possibly, a major mediator of inflammation in body tissues. The role of GM-CSF in the activation of microglia (CNS resident macrophages) and the consequent impacts on neuronal survival, excitability, and synaptic transmission are widely unknown, however. Here, we focused on electrical neuronal network rhythms in the gamma frequency band (30–70 Hz). Gamma oscillations are fundamental to higher brain functions, such as perception, attention, and memory, and they are exquisitely sensitive to metabolic and oxidative stress. Methods We explored the effects of chronic GM-CSF exposure (72 h) on microglia in male rat organotypic hippocampal slice cultures (in situ), i.e., postnatal cortex tissue lacking leukocyte invasion (adaptive immunity). We applied extracellular electrophysiological recordings of local field potential, immunohistochemistry, design-based stereology, biochemical analysis, and pharmacological ablation of microglia. Results GM-CSF triggered substantial proliferation of microglia (microgliosis). By contrast, the release of proinflammatory cytokines (IL-6, TNF-α) and nitric oxide, the hippocampal cytoarchitecture as well as the morphology of parvalbumin-positive inhibitory interneurons were unaffected. Notably, GM-CSF induced concentration-dependent, long-lasting disturbances of gamma oscillations, such as slowing (beta frequency band) and neural burst firing (hyperexcitability), which were not mimicked by the T lymphocyte cytokine IL-17. These disturbances were attenuated by depletion of the microglial cell population with liposome-encapsulated clodronate. In contrast to priming with the cytokine IFN-γ (type II interferon), GM-CSF did not cause inflammatory neurodegeneration when paired with the TLR4 ligand LPS. Conclusions GM-CSF has a unique role in the activation of microglia, including the potential to induce neuronal network dysfunction. These immunomodulatory properties might contribute to cognitive impairment and/or epileptic seizure development in disease featuring elevated GM-CSF levels, blood-brain barrier leakage, and/or T cell infiltration.
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Affiliation(s)
- Hasan Onur Dikmen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Marc Hemmerich
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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8
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Kobayashi K, Umeda K, Ihara F, Tanaka S, Yamagishi J, Suzuki Y, Nishikawa Y. Transcriptome analysis of the effect of C-C chemokine receptor 5 deficiency on cell response to Toxoplasma gondii in brain cells. BMC Genomics 2019; 20:705. [PMID: 31506064 PMCID: PMC6737708 DOI: 10.1186/s12864-019-6076-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 09/04/2019] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Infection with Toxoplasma gondii is thought to damage the brain and be a risk factor for neurological and psychotic disorders. The immune response-participating chemokine system has recently been considered vital for brain cell signaling and neural functioning. Here, we investigated the effect of the deficiency of C-C chemokine receptor 5 (CCR5), which is previously reported to be associated with T. gondii infection, on gene expression in the brain during T. gondii infection and the relationship between CCR5 and the inflammatory response against T. gondii infection in the brain. RESULTS We performed a genome-wide comprehensive analysis of brain cells from wild-type and CCR5-deficient mice. Mouse primary brain cells infected with T. gondii were subjected to RNA sequencing. The expression levels of some genes, especially in astrocytes and microglia, were altered by CCR5-deficiency during T. gondii infection, and the gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed an enhanced immune response in the brain cells. The expression levels of genes which were highly differentially expressed in vitro were also investigated in the mouse brains during the T. gondii infections. Among the genes tested, only Saa3 (serum amyloid A3) showed partly CCR5-dependent upregulation during the acute infection phase. However, analysis of the subacute phase showed that in addition to Saa3, Hmox1 may also contribute to the protection and/or pathology partly via the CCR5 pathway. CONCLUSIONS Our results indicate that CCR5 is involved in T. gondii infection in the brain where it contributes to inflammatory responses and parasite elimination. We suggest that the inflammatory response by glial cells through CCR5 might be associated with neurological injury during T. gondii infection to some extent.
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Affiliation(s)
- Kaoru Kobayashi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Kousuke Umeda
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Fumiaki Ihara
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Sachi Tanaka
- Division of Animal Science, Department of Agricultural and Life Sciences, Faculty of Agriculture, Shinshu University, Minamiminowa, Nagano, Japan
| | - Junya Yamagishi
- Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yutaka Suzuki
- Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Yoshifumi Nishikawa
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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Hemmati S, Sadeghi MA, Mohammad Jafari R, Yousefi-Manesh H, Dehpour AR. The antidepressant effects of GM-CSF are mediated by the reduction of TLR4/NF-ĸB-induced IDO expression. J Neuroinflammation 2019; 16:117. [PMID: 31153376 PMCID: PMC6545198 DOI: 10.1186/s12974-019-1509-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/21/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Indoleamine 2, 3-dioxygenase 1 (IDO) is responsible for the progression of the kynurenine pathway. This pathway has been implicated in the pathophysiology of inflammation-induced depression in which conventional antidepressants are not effective. It has been reported that granulocyte-macrophage stimulating factor (GM-CSF) could interfere with the induction of IDO in septic patients. We hypothesized that GM-CSF could exert antidepressant effects through IDO downregulation in a model for acute inflammation-induced depression. METHODS To produce the model, lipopolysaccharide (LPS) (0.83 mg/kg) was administered intraperitoneally to mice. It has been well documented that LPS mediates IDO overexpression through TLR4/NF-ĸB signaling. In the treatment group, mice received GM-CSF (30 μg/kg, i.p.) thirty minutes prior to LPS injection. A validated selective serotonin reuptake inhibitor, fluoxetine (30 mg/kg i.p.), was also administered to an experimental group 30 min prior to LPS. Depressive-like behaviors were evaluated based on the duration of immobility in the forced swim test. To confirm that GM-CSF interferes with IDO induction in LPS treated mice, real-time PCR was used to quantify IDO mRNA expression. Furthermore, in order to study whether GM-CSF inhibits the TLR4/NF-ĸB signaling pathway, we measured levels ofpNF-ĸB and TLR4 by western blotting. RESULTS GM-CSF demonstrated significant antidepressant activity in the presence of LPS on immobility (p < .001) and latency (p = .010) times in the forced swim test. In contrast, fluoxetine did not show any antidepressant activity on either immobility (p = .918) or latency (p = .566) times. Furthermore, GM-CSF inhibited the increase in IDO mRNA (p = .032) and protein (p = .016) expression as a result of LPS administration. A similar trend was observed for TLR4 (p = .042) and pNF-ĸB (p = .026) expression as both proteins showed reduced expression levels in the GM-CSF-pretreated group compared to the untreated (LPS) group. CONCLUSION Our results propose a promising antidepressant effect for GM-CSF possibly through the downregulation of IDO expression. This remedying effect of GM-CSF could be attributed to decreased amounts of TLR4 and active NF-ĸB in the treated mice.
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Affiliation(s)
- Sara Hemmati
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Amin Sadeghi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Razieh Mohammad Jafari
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Hasan Yousefi-Manesh
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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10
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Schutt CR, Gendelman HE, Mosley RL. Tolerogenic bone marrow-derived dendritic cells induce neuroprotective regulatory T cells in a model of Parkinson's disease. Mol Neurodegener 2018; 13:26. [PMID: 29783988 PMCID: PMC5963189 DOI: 10.1186/s13024-018-0255-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 05/02/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) increases regulatory T cell (Treg) number and function with control of neuroinflammation and neuronal protection in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinson's disease (PD). Recently, we demonstrated in an early phase 1 clinical trial that GM-CSF also improves motor skills in PD patients. However, the mechanisms of Treg induction and its effects on neuroprotective responses remain unknown. As GM-CSF induces tolerogenic dendritic cells (DCs) that in turn convert conventional T cells to Tregs, the pathways for DC induction of Tregs were assessed. METHODS Following differentiation, bone marrow-derived dendritic cells (BMDCs) were cultured in media or GM-CSF with or without post-culture stimulation with nitrated α-synuclein (N-α-Syn). Expression of cell surface co-stimulatory molecules and proinflammatory cytokines, and induction of Tregs were evaluated. The neuroprotective capacity of tolerogenic BMDCs was assessed by adoptive transfer to MPTP-intoxicated mice. The extent of neuroinflammation and numbers of surviving dopaminergic neurons were assessed in relation to Treg numbers. RESULTS Co-culture of differentiated BMDCs with conventional T cells led to Treg induction. Stimulation of BMDCs with N-α-Syn increased expression of co-stimulatory molecules and proinflammatory cytokines, with modest increases in Treg numbers. In contrast, continued culture of BMDCs with GM-CSF modestly altered expression of co-stimulatory molecules and proinflammatory cytokines and chemokines, but decreased Treg induction. Continued culture in GM-CSF and combined stimulation with N-α-Syn reduced Treg induction to the lowest levels. Adoptive transfer of tolerogenic BMDCs to MPTP-intoxicated mice increased splenic Tregs, attenuated neuroinflammatory responses, and protected nigrostriatal dopaminergic neurons. CONCLUSIONS GM-CSF acts broadly to differentiate DCs and affect immune transformation from effector to regulatory immune responses. DCs skew such immune responses by increasing Treg numbers and activities that serve to attenuate proinflammatory responses and augment neuroprotection.
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Affiliation(s)
- Charles R Schutt
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, USA
| | - Howard E Gendelman
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, USA
| | - R Lee Mosley
- Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, NE, USA. .,Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985930 Nebraska Medical Center, Omaha, NE 68198-5930, USA.
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11
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Brain STAT5 signaling modulates learning and memory formation. Brain Struct Funct 2018; 223:2229-2241. [PMID: 29460051 DOI: 10.1007/s00429-018-1627-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 02/12/2018] [Indexed: 01/02/2023]
Abstract
The signal transducer and activator of transcription 5 (STAT5) is a transcription factor recruited by numerous cytokines. STAT5 is important for several physiological functions, including body and tissue growth, mammary gland development, immune system and lipid metabolism. However, the role of STAT5 signaling for brain functions is still poorly investigated, especially regarding cognitive aspects. Therefore, the objective of the present study was to investigate whether brain STAT5 signaling modulates learning and memory formation. For this purpose, brain-specific STAT5 knockout (STAT5 KO) mice were studied in well-established memory tests. Initially, we confirmed a robust reduction in STAT5a and STAT5b mRNA levels in different brain structures of STAT5 KO mice. STAT5 KO mice showed no significant alterations in metabolism, growth, somatotropic axis and spontaneous locomotor activity. In contrast, brain-specific STAT5 ablation impaired learning and memory formation in the novel object recognition, Barnes maze and contextual fear conditioning tests. To unravel possible mechanisms that might underlie the memory deficits of STAT5 KO mice, we assessed neurogenesis in the hippocampus, but no significant differences were observed between groups. On the other hand, reduced insulin-like growth factor-1 (IGF-1) mRNA expression was found in the hippocampus and hypothalamus of STAT5 KO mice. These findings collectively indicate that brain STAT5 signaling is required to attain normal learning and memory. Therefore, STAT5 is an important downstream cellular mechanism shared by several cytokines to regulate cognitive functions.
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Imitola J, Rasouli J, Watanabe F, Mahajan K, Sharan AD, Ciric B, Zhang GX, Rostami A. Elevated expression of granulocyte-macrophage colony-stimulating factor receptor in multiple sclerosis lesions. J Neuroimmunol 2017; 317:45-54. [PMID: 29290406 DOI: 10.1016/j.jneuroim.2017.12.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 12/17/2017] [Accepted: 12/19/2017] [Indexed: 01/06/2023]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease that disproportionately affects young adults, leading to disability and high costs to society. Infiltration of T cells and monocytes into the central nervous system (CNS) is critical for disease initiation and progression. However, despite a great deal of effort the molecular mechanisms by which immune cells initiate and perpetuate CNS damage in MS have not yet been elucidated. In experimental autoimmune encephalomyelitis (EAE), an animal model of MS, granulocyte-macrophage colony-stimulating factor (GM-CSF) produced by pathogenic Th1 and Th17 cells is critical for the recruitment of monocytes into the CNS during the initial stage of disease. We and others have recently shown that, compared with healthy individuals, MS patients have greater numbers of CD4+ and CD8+ T cells that produce GM-CSF. Here, we describe the expression of GM-CSF and its receptor, GM-CSFR, in normal brain and MS lesions. Our data show that in acute and chronic MS lesions, microglia and astrocytes have upregulated expression of GM-CSFR; in addition, we show that GM-CSF-associated molecules are also upregulated in MS lesions. These findings further strengthen the argument that GM-CSF signaling contributes to MS pathogenesis.
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Affiliation(s)
- Jaime Imitola
- Department of Neurology, Division of Multiple Sclerosis and Neuroimmunology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA 19107, USA; Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University, OH, 43210, USA; Laboratory for Neural Stem Cells and Functional Neurogenetics, Departments of Neurology and Neuroscience, College of Medicine, The Ohio State University, OH, 43210, USA
| | - Javad Rasouli
- Department of Neurology, Division of Multiple Sclerosis and Neuroimmunology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA 19107, USA
| | - Fumihiro Watanabe
- Division of Neuroimmunology and Multiple Sclerosis, The Ohio State University, OH, 43210, USA; Laboratory for Neural Stem Cells and Functional Neurogenetics, Departments of Neurology and Neuroscience, College of Medicine, The Ohio State University, OH, 43210, USA
| | - Kader Mahajan
- Department of Neurology, Division of Multiple Sclerosis and Neuroimmunology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA 19107, USA
| | - Aswhini D Sharan
- Department of Neurosurgery, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA, 19107, USA
| | - Bogoljub Ciric
- Department of Neurology, Division of Multiple Sclerosis and Neuroimmunology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA 19107, USA
| | - Guang-Xian Zhang
- Department of Neurology, Division of Multiple Sclerosis and Neuroimmunology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA 19107, USA
| | - Abdolmohamad Rostami
- Department of Neurology, Division of Multiple Sclerosis and Neuroimmunology, Thomas Jefferson University, 900 Walnut Street, Suite 300, Philadelphia, PA 19107, USA.
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Sepulveda-Diaz JE, Ouidja MO, Socias SB, Hamadat S, Guerreiro S, Raisman-Vozari R, Michel PP. A simplified approach for efficient isolation of functional microglial cells: Application for modeling neuroinflammatory responsesin vitro. Glia 2016; 64:1912-24. [DOI: 10.1002/glia.23032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 05/24/2016] [Accepted: 06/30/2016] [Indexed: 11/12/2022]
Affiliation(s)
- Julia E. Sepulveda-Diaz
- Institut National De La Santé Et De La Recherche Médicale, U 1127, CNRS, Unité Mixte De Recherche (UMR) 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut Du Cerveau Et De La Moelle Epinière, ICM; Paris France
| | - Mohand O. Ouidja
- Laboratoire Croissance, Régénération, Réparation Et Régénération Tissulaires (CRRET)/EAC CNRS 7149, Université Paris Est Créteil, Université Paris Est; Créteil France
| | - Sergio B. Socias
- Institut National De La Santé Et De La Recherche Médicale, U 1127, CNRS, Unité Mixte De Recherche (UMR) 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut Du Cerveau Et De La Moelle Epinière, ICM; Paris France
- Facultad De Bioquímica, Química Y Farmacia (UNT), Instituto Superior De Investigaciones Biológicas, INSIBIO (CONICET-UNT) and Instituto De Química Biológica “Dr Bernabé Bloj,”; Tucumán Argentina
| | - Sabah Hamadat
- Institut National De La Santé Et De La Recherche Médicale, U 1127, CNRS, Unité Mixte De Recherche (UMR) 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut Du Cerveau Et De La Moelle Epinière, ICM; Paris France
| | - Serge Guerreiro
- Institut National De La Santé Et De La Recherche Médicale, U 1127, CNRS, Unité Mixte De Recherche (UMR) 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut Du Cerveau Et De La Moelle Epinière, ICM; Paris France
| | - Rita Raisman-Vozari
- Institut National De La Santé Et De La Recherche Médicale, U 1127, CNRS, Unité Mixte De Recherche (UMR) 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut Du Cerveau Et De La Moelle Epinière, ICM; Paris France
| | - Patrick P. Michel
- Institut National De La Santé Et De La Recherche Médicale, U 1127, CNRS, Unité Mixte De Recherche (UMR) 7225, Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, Institut Du Cerveau Et De La Moelle Epinière, ICM; Paris France
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RNA sequencing reveals region-specific molecular mechanisms associated with epileptogenesis in a model of classical hippocampal sclerosis. Sci Rep 2016; 6:22416. [PMID: 26935982 PMCID: PMC4776103 DOI: 10.1038/srep22416] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 02/15/2016] [Indexed: 01/20/2023] Open
Abstract
We report here the first complete transcriptome analysis of the dorsal (dDG) and ventral dentate gyrus (vDG) of a rat epilepsy model presenting a hippocampal lesion with a strict resemblance to classical hippocampal sclerosis (HS). We collected the dDG and vDG by laser microdissection 15 days after electrical stimulation and performed high-throughput RNA-sequencing. There were many differentially regulated genes, some of which were specific to either of the two sub-regions in stimulated animals. Gene ontology analysis indicated an enrichment of inflammation-related processes in both sub-regions and of axonal guidance and calcium signaling processes exclusively in the vDG. There was also a differential regulation of genes encoding molecules involved in synaptic function, neural electrical activity and neuropeptides in stimulated rats. The data presented here suggests, in the time point analyzed, a remarkable interaction among several molecular components which takes place in the damaged hippocampi. Furthermore, even though similar mechanisms may function in different regions of the DG, the molecular components involved seem to be region specific.
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Association Between Microglia, Inflammatory Factors, and Complement with Loss of Hippocampal Mossy Fiber Synapses Induced by Trimethyltin. Neurotox Res 2016; 30:53-66. [PMID: 26892644 DOI: 10.1007/s12640-016-9606-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 12/16/2022]
Abstract
Complement-associated factors are implicated in pathogen presentation, neurodegeneration, and microglia resolution of tissue injury. To characterize complement activation with microglial clearance of degenerating mossy fiber boutons, hippocampal dentate granule neurons were ablated in CD-1 mice with trimethyltin (TMT; 2.2 mg/kg, i.p.). Neuronal apoptosis was accompanied by amoeboid microglia and elevations in tumor necrosis factor [Tnfa], interleukin 1β [Il1b], and Il6 mRNA and C1q protein. Inos mRNA levels were unaltered. Silver degeneration and synaptophysin staining indicated loss of synaptic innervation to CA3 pyramidal neurons. Reactive microglia with thickened bushy morphology showed co-localization of synaptophysin+ fragments. The initial response at 2 days post-TMT included transient elevations in Tnfa, Il1b, Il6, and Inos mRNA levels. A concurrent increase at 2 days was observed in arginase-1 [Arg1], Il10, transforming growth factor β1 [Tgfb1], and chitinase 3 like-3 [Ym1] mRNA levels. At 2 days, C1q protein was evident in the CA3 with elevated C1qa, C1qb, C3, Cr3a, and Cr3b mRNA levels. mRNA levels remained elevated at 5 days, returning to control by 14 days, corresponding to silver degeneration. mRNA levels for pentraxin3 (Ptx3) were elevated on day 2 and Ptx1 was not altered. Our data suggest an association between microglia reactivity, the induction of anti-inflammatory genes concurrent with pro-inflammatory genes and the expression of complement-associated factors with the degeneration of synapses following apoptotic neuronal loss.
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Wang L, Guo XL. Molecular regulation of galectin-3 expression and therapeutic implication in cancer progression. Biomed Pharmacother 2016; 78:165-171. [PMID: 26898438 DOI: 10.1016/j.biopha.2016.01.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/05/2016] [Accepted: 01/13/2016] [Indexed: 12/18/2022] Open
Abstract
Galectin-3, a multifunctional protein, distributes inside and outside cells and plays an important role in tumor cell adhesion, proliferation, differentiation, angiogenesis, and metastasis in multiple tumors. Changes in galectin-3 expression are commonly seen in cancer and pre-cancerous conditions. Therefore, to understand the molecular regulation of galectin-3 expression could aid the development of new approach for cancer treatment. This review summarizes different expression of galectin-3 in cancer cells and patients' serum, the regulation mechanism and the potential therapeutic targets of galectin-3 in cancer progression.
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Affiliation(s)
- Lei Wang
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, PR China
| | - Xiu-Li Guo
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, PR China.
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Spanos JP, Hsu NJ, Jacobs M. Microglia are crucial regulators of neuro-immunity during central nervous system tuberculosis. Front Cell Neurosci 2015; 9:182. [PMID: 26041993 PMCID: PMC4435040 DOI: 10.3389/fncel.2015.00182] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/27/2015] [Indexed: 01/11/2023] Open
Abstract
Mycobacterium tuberculosis (M. tuberculosis) infection of the central nervous system (CNS) is the most devastating manifestation of tuberculosis (TB), with both high mortality and morbidity. Although research has been fueled by the potential therapeutic target microglia offer against neurodegenerative inflammation, their part in TB infection of the CNS has not been fully evaluated nor elucidated. Yet, as both the preferential targets of M. tuberculosis and the immune-effector cells of the CNS, microglia are likely to be key determinants of disease severity and clinical outcomes. Following pathogen recognition, bacilli are internalized and capable of replicating within microglia. Cellular activation ensues, utilizing signaling molecules that may be neurotoxic. Central to initiating, orchestrating and modulating the tuberculous immune response is microglial secretion of cytokines and chemokines. However, the neurological environment is unique in that inflammatory signals, which appear to be damaging in the periphery, could be beneficial by governing neuronal survival, regeneration and differentiation. Furthermore, microglia are important in the recruitment of peripheral immune cells and central to defining the pro-inflammatory milieu of which neurotoxicity may result from many of the participating local or recruited cell types. Microglia are capable of both presenting antigen to infiltrating CD4(+) T-lymphocytes and inducing their differentiation-a possible correlate of protection against M. tuberculosis infection. Clarifying the nature of the immune effector molecules secreted by microglia, and the means by which other CNS-specific cell types govern microglial activation or modulate their responses is critical if improved diagnostic and therapeutic strategies are to be attained. Therefore, this review evaluates the diverse roles microglia play in the neuro-immunity to M. tuberculosis infection of the CNS.
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Affiliation(s)
- Jonathan Paul Spanos
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Nai-Jen Hsu
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Muazzam Jacobs
- Division of Immunology, Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa ; National Health Laboratory Service Johannesburg, South Africa
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Bipolar/rod-shaped microglia are proliferating microglia with distinct M1/M2 phenotypes. Sci Rep 2014; 4:7279. [PMID: 25452009 PMCID: PMC4250916 DOI: 10.1038/srep07279] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 11/12/2014] [Indexed: 01/01/2023] Open
Abstract
Microglia are generally considered the resident immune cells in the central nervous system (CNS) that regulate the primary events of neuroinflammatory responses. Microglia also play key roles in repair and neurodegeneration of the CNS after injury. Recent studies showed that trains of bipolar/rod-shaped microglia align end-to-end along the CNS injury site during the initial recovery phase. However, the cellular characteristics of bipolar/rod-shaped microglia remain largely unknown. Here, we established a highly reproducible in vitro culture model system to enrich and characterize bipolar/rod-shaped microglia by simply generating multiple scratches on a poly-d-lysine/laminin-coated culture dish. Trains of bipolar/rod-shaped microglia formed and aligned along the scratches in a manner that morphologically resembled microglial trains observed in injured brain. These bipolar/rod-shaped microglia were highly proliferative and expressed various M1/M2 markers. Further analysis revealed that these bipolar/rod-shaped microglia quickly transformed into amoeboid microglia within 30 minutes of lipopolysaccharide treatment, leading to the upregulation of pro-inflammatory cytokine gene expression and the activation of Jak/Stat. In summary, our culture system provides a model to further characterize this highly dynamic cell type. We suggest that bipolar/rod-shaped microglia are crucial for repairing the damaged CNS and that the molecular mechanisms underlying their morphological changes may serve as therapeutic biomarkers.
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Guha SK, Tillu R, Sood A, Patgaonkar M, Nanavaty IN, Sengupta A, Sharma S, Vaidya VA, Pathak S. Single episode of mild murine malaria induces neuroinflammation, alters microglial profile, impairs adult neurogenesis, and causes deficits in social and anxiety-like behavior. Brain Behav Immun 2014; 42:123-37. [PMID: 24953429 DOI: 10.1016/j.bbi.2014.06.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 06/09/2014] [Accepted: 06/13/2014] [Indexed: 12/26/2022] Open
Abstract
Cerebral malaria is associated with cerebrovascular damage and neurological sequelae. However, the neurological consequences of uncomplicated malaria, the most prevalent form of the disease, remain uninvestigated. Here, using a mild malaria model, we show that a single Plasmodium chabaudi adami infection in adult mice induces neuroinflammation, neurogenic, and behavioral changes in the absence of a blood-brain barrier breach. Using cytokine arrays we show that the infection induces differential serum and brain cytokine profiles, both at peak parasitemia and 15days post-parasite clearance. At the peak of infection, along with the serum, the brain also exhibited a definitive pro-inflammatory cytokine profile, and gene expression analysis revealed that pro-inflammatory cytokines were also produced locally in the hippocampus, an adult neurogenic niche. Hippocampal microglia numbers were enhanced, and we noted a shift to an activated profile at this time point, accompanied by a striking redistribution of the microglia to the subgranular zone adjacent to hippocampal neuronal progenitors. In the hippocampus, a distinct decline in progenitor turnover and survival was observed at peak parasitemia, accompanied by a shift from neuronal to glial fate specification. Studies in transgenic Nestin-GFP reporter mice demonstrated a decline in the Nestin-GFP(+)/GFAP(+) quiescent neural stem cell pool at peak parasitemia. Although these cellular changes reverted to normal 15days post-parasite clearance, specific brain cytokines continued to exhibit dysregulation. Behavioral analysis revealed selective deficits in social and anxiety-like behaviors, with no change observed in locomotor, cognitive, and depression-like behaviors, with a return to baseline at recovery. Collectively, these findings indicate that even a single episode of mild malaria results in alterations of the brain cytokine profile, causes specific behavioral dysfunction, is accompanied by hippocampal microglial activation and redistribution, and a definitive, but transient, suppression of adult hippocampal neurogenesis.
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Affiliation(s)
- Suman K Guha
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Rucha Tillu
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Ankit Sood
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Mandar Patgaonkar
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Ishira N Nanavaty
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Arjun Sengupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Shobhona Sharma
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
| | - Vidita A Vaidya
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India.
| | - Sulabha Pathak
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India.
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Warsi J, Luo D, Elvira B, Jilani K, Shumilina E, Hosseinzadeh Z, Lang F. Upregulation of excitatory amino acid transporters by coexpression of Janus kinase 3. J Membr Biol 2014; 247:713-20. [PMID: 24928228 DOI: 10.1007/s00232-014-9695-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/26/2014] [Indexed: 10/25/2022]
Abstract
Janus kinase 3 (JAK3) contributes to cytokine receptor signaling, confers cell survival and stimulates cell proliferation. The gain of function mutation JAK3(A572V) is found in acute megakaryoplastic leukemia. Replacement of ATP coordinating lysine by alanine yields inactive JAK3(K855A). Most recent observations revealed the capacity of JAK3 to regulate ion transport. This study thus explored whether JAK3 regulates glutamate transporters EAAT1-4, carriers accomplishing transport of glutamate and aspartate in a variety of cells including intestinal cells, renal cells, glial cells, and neurons. To this end, EAAT1, 2, 3, or 4 were expressed in Xenopus oocytes with or without additional expression of mouse wild-type JAK3, constitutively active JAK3(A568V) or inactive JAK3(K851A), and electrogenic glutamate transport was determined by dual electrode voltage clamp. Moreover, Ussing chamber was employed to determine electrogenic glutamate transport in intestine from mice lacking functional JAK3 (jak3(-/-)) and from corresponding wild-type mice (jak3(+/+)). As a result, in EAAT1, 2, 3, or 4 expressing oocytes, but not in oocytes injected with water, addition of glutamate to extracellular bath generated an inward current (Ig), which was significantly increased following coexpression of JAK3. Ig in oocytes expressing EAAT3 was further increased by JAK3(A568V) but not by JAK3(K851A). Ig in EAAT3 + JAK3 expressing oocytes was significantly decreased by JAK3 inhibitor WHI-P154 (22 µM). Kinetic analysis revealed that JAK3 increased maximal Ig and significantly reduced the glutamate concentration required for half maximal Ig (Km). Intestinal electrogenic glutamate transport was significantly lower in jak3(-/-) than in jak3(+/+) mice. In conclusion, JAK3 is a powerful regulator of excitatory amino acid transporter isoforms.
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Affiliation(s)
- Jamshed Warsi
- Department of Physiology I, University of Tuebingen, Gmelinstr. 5, 72076, Tuebingen, Germany
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Kitic M, Wimmer I, Adzemovic M, Kögl N, Rudel A, Lassmann H, Bradl M. Thymic stromal lymphopoietin is expressed in the intact central nervous system and upregulated in the myelin-degenerative central nervous system. Glia 2014; 62:1066-74. [PMID: 24668732 PMCID: PMC4237118 DOI: 10.1002/glia.22662] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 02/11/2014] [Accepted: 03/07/2014] [Indexed: 12/13/2022]
Abstract
Thymic stromal lymphopoietin (TSLP) is an epithelial cytokine expressed at barrier surfaces of the skin, gut, nose, lung, and the maternal/fetal interphase. At these sites, it is important for the generation and maintenance of non-inflammatory, tissue-resident dendritic cell responses. We show here that TSLP is also expressed in the central nervous system (CNS) where it is produced by choroid plexus epithelial cells and astrocytes in the spinal cord. Under conditions of low-grade myelin degeneration, the numbers of TSLP-expressing astrocytes increase, and microglia express transcripts for the functional TSLP receptor dimer indicating that these cells are targets for TSLP in the myelin-degenerative CNS.
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Affiliation(s)
- Maja Kitic
- Medical University Vienna, Center for Brain Research, Department of Neuroimmunology, Spitalgasse 4, 1090, Vienna, Austria
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Button EB, Mitchell AS, Domingos MM, Chung JHJ, Bradley RM, Hashemi A, Marvyn PM, Patterson AC, Stark KD, Quadrilatero J, Duncan RE. Microglial cell activation increases saturated and decreases monounsaturated fatty acid content, but both lipid species are proinflammatory. Lipids 2014; 49:305-16. [PMID: 24473753 DOI: 10.1007/s11745-014-3882-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 01/06/2014] [Indexed: 12/31/2022]
Abstract
Neuroinflammation is a component of age-related neurodegenerative diseases and cognitive decline. Saturated (SFA) and monounsaturated (MUFA) fatty acids are bioactive molecules that may play different extrinsic and intrinsic roles in neuroinflammation, serving as exogenous ligands for cellular receptors, or endogenous components of cell structural, energetic and signaling pathways. We determined the fatty acyl profile of BV2 microglial cells before and after acute activation with lipopolysaccharide (LPS). We also investigated the effect of SFA and MUFA pretreatment on the production of an invasive, neurotoxic phenotype in BV2 cells. Acute activation of BV2 microglia resulted in an increase in the relative content of SFA (12:0, 16:0, 18:0, 20:0, 22:0, and 24:0 increased significantly), and a relative decrease in the content of MUFA (16:1n7, 18:1n7, 18:1n9, 20:1n9, 24:1n9 decreased significantly). In agreement, the major stearoyl-CoA desaturase (SCD) isoform in BV2 cells, SCD2, was significantly down-regulated by LPS. We next treated cells with SFA (16:0 or 18:0) or MUFA (16:1n7 or 18:1n9), and found that levels of secreted IL6 were increased, as was secreted MMP9-mediated proteolytic activity. To test the functional significance, we treated SH-SY5Y neuronal cells with conditioned medium from BV2 cells pretreated with fatty acids, and found a small but significant induction of cell death. Our findings suggest differential intrinsic roles for SFA and MUFA in activated microglial cells, but similar extrinsic roles for these fatty acid species in inducing activation. Expansion of SFA is important during microglial cell activation, but either supplemental SFA or MUFA may contribute to chronic low-grade neuroinflammation.
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Affiliation(s)
- Emily B Button
- Department of Kinesiology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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Acevedo G, Padala NK, Ni L, Jonakait GM. Astrocytes inhibit microglial surface expression of dendritic cell-related co-stimulatory molecules through a contact-mediated process. J Neurochem 2013; 125:575-87. [PMID: 23439211 DOI: 10.1111/jnc.12221] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 02/08/2013] [Accepted: 02/08/2013] [Indexed: 12/25/2022]
Abstract
Murine microglia cultured in isolation were treated sequentially with granulocyte/monocyte colony-stimulating factor (GM-CSF) (5 days) and lipopolysaccharide (LPS) (2 days) to elicit a mature dendritic cell-like (DC-like) phenotype. Examined by flow cytometry microglia thus isolated show high surface expression of CD11c together with the co-stimulatory molecules CD40, CD80, and CD86 that are necessary for T-cell activation. In contrast, microglia co-cultured with astrocytes fail to achieve a mature DC-like phenotype. Contact with the astrocytic environment is necessary for the inhibition. Failure was not because of a more rapid degradation of protein. Bone marrow-derived cells, like microglia, were prevented by astrocytes from attaining a mature DC phenotype. Although GM-CSF pre-treatment substantially increases mRNA of co-stimulatory molecules and major histocompatibility complex (MHC) Class II in isolated microglia, co-cultured microglia await treatment with LPS to up-regulate them. In contrast, western blot and immunocytochemical analysis revealed that it is not a failure of transcription or translation, nor is it a more rapid degradation of mRNA that is responsible for the low surface expression; rather microglia co-cultured with astrocytes produce mRNA and protein but do not traffic the protein onto the cell surface.
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Parajuli B, Sonobe Y, Kawanokuchi J, Doi Y, Noda M, Takeuchi H, Mizuno T, Suzumura A. GM-CSF increases LPS-induced production of proinflammatory mediators via upregulation of TLR4 and CD14 in murine microglia. J Neuroinflammation 2012; 9:268. [PMID: 23234315 PMCID: PMC3565988 DOI: 10.1186/1742-2094-9-268] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 11/26/2012] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Microglia are resident macrophage-like cells in the central nervous system (CNS) and cause innate immune responses via the LPS receptors, Toll-like receptor (TLR) 4 and CD14, in a variety of neuroinflammatory disorders including bacterial infection, Alzheimer's disease, and amyotrophic lateral sclerosis. Granulocyte macrophage-colony stimulating factor (GM-CSF) activates microglia and induces inflammatory responses via binding to GM-CSF receptor complex composed of two different subunit GM-CSF receptor α (GM-CSFRα) and common β chain (βc). GM-CSF has been shown to be associated with neuroinflammatory responses in multiple sclerosis and Alzheimer's disease. However, the mechanisms how GM-CSF promotes neuroinflammation still remain unclear. METHODS Microglia were stimulated with 20 ng/ml GM-CSF and the levels of TLR4 and CD14 expression were evaluated by RT-PCR and flowcytometry. LPS binding was analyzed by flowcytometry. GM-CSF receptor complex was analyzed by immunocytochemistry. The levels of IL-1β, IL-6 and TNF-α in culture supernatant of GM-CSF-stimulated microglia and NF-κB nuclear translocation were determined by ELISA. Production of nitric oxide (NO) was measured by the Griess method. The levels of p-ERK1/2, ERK1/2, p-p38 and p38 were assessed by Western blotting. Statistically significant differences between experimental groups were determined by one-way ANOVA followed by Tukey test for multiple comparisons. RESULTS GM-CSF receptor complex was expressed in microglia. GM-CSF enhanced TLR4 and CD14 expressions in microglia and subsequent LPS-binding to the cell surface. In addition, GM-CSF priming increased LPS-induced NF-κB nuclear translocation and production of IL-1β, IL-6, TNF-α and NO by microglia. GM-CSF upregulated the levels of p-ERK1/2 and p-p38, suggesting that induction of TLR4 and CD14 expression by GM-CSF was mediated through ERK1/2 and p38, respectively. CONCLUSIONS These results suggest that GM-CSF upregulates TLR4 and CD14 expression in microglia through ERK1/2 and p38, respectively, and thus promotes the LPS receptor-mediated inflammation in the CNS.
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Affiliation(s)
- Bijay Parajuli
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Yoshifumi Sonobe
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Jun Kawanokuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Yukiko Doi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Mariko Noda
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
- Department of Anatomy, School of Medicine, Keio University, Shinanomachi, Tokyo, Japan
| | - Hideyuki Takeuchi
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Tetsuya Mizuno
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Akio Suzumura
- Department of Neuroimmunology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
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Proliferative and survival effects of PUMA promote angiogenesis. Cell Rep 2012; 2:1272-85. [PMID: 23122957 DOI: 10.1016/j.celrep.2012.09.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 06/05/2012] [Accepted: 09/24/2012] [Indexed: 01/08/2023] Open
Abstract
The p53 upregulated modulator of apoptosis (PUMA) is known as an essential apoptosis inducer. Here, we report the seemingly paradoxical finding that PUMA is a proangiogenic factor critically required for the proliferation and survival of vascular and microglia cells. Strikingly, Puma deficiency by genetic deletion or small hairpin RNA knockdown inhibited developmental and pathological angiogenesis and reduced microglia numbers in vivo, whereas Puma gene delivery increased angiogenesis and cell survival. Mechanistically, we revealed that PUMA plays a critical role in regulating autophagy by modulating Erk activation and intracellular calcium level. Our findings revealed an unexpected function of PUMA in promoting angiogenesis and warrant more careful investigations into the therapeutic potential of PUMA in treating cancer and degenerative diseases.
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Dolga AM, Letsche T, Gold M, Doti N, Bacher M, Chiamvimonvat N, Dodel R, Culmsee C. Activation of KCNN3/SK3/K(Ca)2.3 channels attenuates enhanced calcium influx and inflammatory cytokine production in activated microglia. Glia 2012; 60:2050-64. [PMID: 23002008 DOI: 10.1002/glia.22419] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 08/23/2012] [Indexed: 11/10/2022]
Abstract
In neurons, small-conductance calcium-activated potassium (KCNN/SK/K(Ca)2) channels maintain calcium homeostasis after N-methyl-D-aspartate (NMDA) receptor activation, thereby preventing excitotoxic neuronal death. So far, little is known about the function of KCNN/SK/K(Ca)2 channels in non-neuronal cells, such as microglial cells. In this study, we addressed the question whether KCNN/SK/K(Ca)2 channels activation affected inflammatory responses of primary mouse microglial cells upon lipopolysaccharide (LPS) stimulation. We found that N-cyclohexyl-N-[2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-4-pyrimidinamine (CyPPA), a positive pharmacological activator of KCNN/SK/K(Ca)2 channels, significantly reduced LPS-stimulated activation of microglia in a concentration-dependent manner. The general KCNN/SK/K(Ca)2 channel blocker apamin reverted these effects of CyPPA on microglial proliferation. Since calcium plays a central role in microglial activation, we further addressed whether KCNN/SK/K(Ca)2 channel activation affected the changes of intracellular calcium levels, [Ca(2+)](i), in microglial cells. Our data show that LPS-induced elevation of [Ca(2+)](i) was attenuated following activation of KCNN2/3/K(Ca)2.2/K(Ca)2.3 channels by CyPPA. Furthermore, CyPPA reduced downstream events including tumor necrosis factor alpha and interleukin 6 cytokine production and nitric oxide release in activated microglia. Further, we applied specific peptide inhibitors of the KCNN/SK/K(Ca)2 channel subtypes to identify which particular channel subtype mediated the observed anti-inflammatory effects. Only inhibitory peptides targeting KCNN3/SK3/K(Ca)2.3 channels, but not KCNN2/SK2/K(Ca)2.2 channel inhibition, reversed the CyPPA-effects on LPS-induced microglial proliferation. These findings revealed that KCNN3/SK3/K(Ca)2.3 channels can modulate the LPS-induced inflammatory responses in microglial cells. Thus, KCNN3/SK3/K(Ca)2.3 channels may serve as a therapeutic target for reducing microglial activity and related inflammatory responses in the central nervous system.
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Affiliation(s)
- Amalia M Dolga
- Institute of Pharmacology and Clinical Pharmacy, Philipps University of Marburg, 35032, Marburg, Germany.
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GM-CSF protects rat photoreceptors from death by activating the SRC-dependent signalling and elevating anti-apoptotic factors and neurotrophins. Graefes Arch Clin Exp Ophthalmol 2012; 250:699-712. [PMID: 22297538 DOI: 10.1007/s00417-012-1932-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Revised: 01/10/2012] [Accepted: 01/11/2012] [Indexed: 10/14/2022] Open
Abstract
BACKGROUND The term retinitis pigmentosa (RP) comprises a heterogeneous group of hereditary and sporadic human retinal degenerative diseases. The molecular and cellular events still remain obscure, thus hiding effective therapies. Granulocyte–macrophage colony-stimulating factor (GM-CSF) is a hematopoietic factor which plays a crucial role in protecting neuronal cells. Binding of GM-CSF to its receptor induces several intracellular signaling pathways and kinases. Here we examined whether GM-CSF has a neuroprotective effect on photoreceptor degeneration in Royal College of Surgeons (RCS) rats. METHODS GM-CSF was injected into the vitreous body of RCS rats either once at the onset of photoreceptor degeneration at day 21, or twice at day 21 and day 42. At day 84, when photoreceptor degeneration is completed, the rats were sacrificed, their eyes enucleated and processed for histological staining and counting the surviving photoreceptor nuclei. The expression of apoptosis-related factors, such as BAD, APAF1 and BCL-2 was examined by Western blot analysis. The expression of neurotrophins such as ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF), and glia-derived neurotrophic actor (GDNF), as well as glial fibrillary acidic protein (GFAP) was analysed by Western blots and immunohistochemistry. The expression of JAK/STAT, ERK1/2 and SRC pathway proteins was assessed by Western blot analysis. RESULTS GM-CSF protects significantly against photoreceptor degeneration in comparison to control group. After a single injection of GM-CSF at P21, a 4-fold increase of photoreceptors was observed, whereas eyes which received a repeated injection of GM-CSF at P42 showed a 10-fold increase of photoreceptors. Western blot analysis revealed a decreased BAD and an increased pBAD and BCL-2 expression, indicating changed expression profiles of apoptosis-related proteins. Neurotrophic factors examined are up-regulated, whereas GFAP was also modulated. At cell signalling levels, GM-CSF activates SRC-dependent STAT3 which is independent of JAK2, while proteins of the ERK1/2 pathway are not affected. CONCLUSIONS The data suggest that GM-CSF is a potent therapeutic agent in photoreceptor degeneration caused by mutation of the receptor tyrosine kinase gene (Mertk), and may be also effective in other photoreceptor degeneration.
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Aspirin-Triggered Lipoxin A4 Attenuates Lipopolysaccharide-Induced Intracellular ROS in BV2 Microglia Cells by Inhibiting the Function of NADPH Oxidase. Neurochem Res 2012; 37:1690-6. [DOI: 10.1007/s11064-012-0776-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2012] [Revised: 03/21/2012] [Accepted: 03/31/2012] [Indexed: 10/28/2022]
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Yamamoto S, Kohsaka S, Nakajima K. Role of cell cycle-associated proteins in microglial proliferation in the axotomized rat facial nucleus. Glia 2012; 60:570-81. [PMID: 22258892 DOI: 10.1002/glia.22291] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 12/15/2011] [Indexed: 11/11/2022]
Abstract
We analyzed cell cycle-associated proteins, including cyclins, cyclin-dependent protein kinases (Cdks), and Cdk inhibitors (CdkIs) in the axotomized rat facial nucleus. Immunoblotting revealed that cyclin A and cyclin D are induced 3-5 days after transection. The induced cyclin A was immunohistochemically recognized in microglia. Cdk2 and Cdk4 were also detected in the facial nucleus. The CdkI p21 was elevated 5 days after axotomy. Inhibition experiments in vitro using a cFms (receptor for macrophage-colony stimulating factor, M-CSF) inhibitor indicated that M-CSF-cFms signaling leads to upregulation of the levels of cyclin A, cyclin D, proliferating cell nuclear antigen (PCNA), and cFms in microglia. The role of cyclin A/Cdk2 activity in M-CSF-dependent microglial proliferation was ascertained using the specific inhibitor purvalanol A. Experiments using specific mitogen-activated protein kinase inhibitors suggested that c-Jun N-terminal kinase (JNK) is associated with M-CSF-dependent induction of cyclins and PCNA, whereas p38 is associated with cFms induction. Both JNK and p38 were proved to be phosphorylated by stimulation with M-CSF. Our results indicated that cyclin A, cyclin D, Cdk2, Cdk4, and p21 are involved in microglial proliferation in the transected facial nucleus, and that the M-CSF-dependent upregulations of cyclins/PCNA and cFms in microglia are differentially regulated by JNK and p38.
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Affiliation(s)
- Shinichi Yamamoto
- Department of Bioinformatics, Faculty of Engineering, Soka University, Tokyo, Japan
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Abstract
We describe a method to prepare postnatal rat brain primary cell cultures composed of astrocytes, oligodendrocytes, and microglia. After 1 week in vitro, the mixed glial cell cultures are free of neurons, meningeal cells and fibroblasts. We developed a simple procedure to selectively harvest enriched populations of each of the three major glial cell types. Because these cells are at a progenitor/immature stage, each can be further cultured separately in serum or serum-free media to yield large quantities of the desired glial cell subpopulations with a high degree of purity in the range of 96-99%. These cell culture models have been used extensively for performing biochemical, molecular, and pharmacological studies using standard assays and obtain sound quantitative data. These studies have given us insights into the development, properties, and functions of rat and mouse glial cells in vitro. The findings have largely been validated and extended in animal models over the last 3 decades. Since this method has been cited in more than 2,500 research papers, the data obtained across laboratories can be compared more readily.
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Affiliation(s)
- Jean de Vellis
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, CA, USA.
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Hamdorf M, Berger A, Schüle S, Reinhardt J, Flory E. PKCδ-induced PU.1 phosphorylation promotes hematopoietic stem cell differentiation to dendritic cells. Stem Cells 2011; 29:297-306. [PMID: 21732487 DOI: 10.1002/stem.564] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Human CD34(+) hematopoietic stem cells (HSCs) exhibit the potential to differentiate into a variety of specialized blood cells. The distinct intracellular mechanisms that control cell fate and lineage commitment of these multipotent cells are not well defined. In this study, we investigate and modulate the signaling processes during HSC differentiation toward myeloid dendritic cells (mDCs). DC differentiation induced by the cytokines Granulocyte macrophage colony-stimulating factor (GM-CSF) and Interleukin-4 (IL-4) led to activation of the Extracellular-signal-regulated kinase (ERK), protein kinase C (PKC), and Janus kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) but not the SAPK/c-Jun NH(2) -terminal kinase and p38 mitogen-activated protein kinase signaling pathways. From the activated signaling pathways the PKC isoform δ was found to phosphorylate the transcription factor PU.1, which is described as one of the key factors for myeloid HSC differentiation. On molecular level, PKCδ regulated PU.1 activity by affecting its transactivation activity, whereas its DNA binding activity remained unaffected. This was accompanied by PKCδ-induced phosphorylation of the PU.1 transactivation domain. Furthermore, treatment with PKC- and ERK1/2-specific signaling inhibitors impaired both HSC differentiation toward mDCs as well as phosphorylation-mediated transactivation activity of PU.1. Taken together, these results provide new insights into the molecular mechanisms promoting the differentiation process of HSCs toward mDCs and introduce the PKC isoform δ as critical mediator.
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Affiliation(s)
- Matthias Hamdorf
- Division of Medical Biotechnology, Paul-Ehrlich-Institut, Langen, Germany
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Kato TA, Monji A, Yasukawa K, Mizoguchi Y, Horikawa H, Seki Y, Hashioka S, Han YH, Kasai M, Sonoda N, Hirata E, Maeda Y, Inoguchi T, Utsumi H, Kanba S. Aripiprazole inhibits superoxide generation from phorbol-myristate-acetate (PMA)-stimulated microglia in vitro: implication for antioxidative psychotropic actions via microglia. Schizophr Res 2011; 129:172-82. [PMID: 21497059 DOI: 10.1016/j.schres.2011.03.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 03/20/2011] [Accepted: 03/21/2011] [Indexed: 12/15/2022]
Abstract
Altered antioxidant status has been implicated in schizophrenia. Microglia, major sources of free radicals such as superoxide (•O(2)(-)), play crucial roles in various brain pathologies. Recent postmortem and imaging studies have indicated microglial activation in the brain of schizophrenic patients. We previously demonstrated that atypical antipsychotics including aripiprazole significantly inhibited the release of nitric oxide and proinflammatory cytokines from interferon-γ-stimulated microglia in vitro. Antioxidative effects of antipsychotics via modulating microglial superoxide generation have never been reported. Therefore, we herein investigated the effects of antipsychotics on the •O(2)(-) generation from phorbol-myristate-acetate (PMA)-stimulated rodent microglia by the electron spin resonance (ESR) spectroscopy and also examined the intracellular mechanism by intracellular Ca(2+) imaging and immunostaining. Neuronal damage induced by microglial activation was also investigated by the co-culture experiment. Among various antipsychotics, only aripiprazole inhibited the •O(2)(-) generation from PMA-stimulated microglia. Aripiprazole proved to inhibit the •O(2)(-) generation through the cascade of protein kinase C (PKC) activation, intracellular Ca(2+) regulation and NADPH oxidase activation via cytosolic p47(phox) translocation to the plasma/phagosomal membranes. Formation of neuritic beading, induced by PMA-stimulated microglia, was attenuated by pretreatment of aripiprazole. D2R antagonism has long been considered as the primary therapeutic action for schizophrenia. Aripiprazole with D2R partial agonism is effective like other antipsychotics with fewer side effects, while aripiprazole's therapeutic mechanism itself remains unclear. Our results imply that aripiprazole may have psychotropic effects by reducing the microglial oxidative reactions and following neuronal reactions, which puts forward a novel therapeutic hypothesis in schizophrenia research.
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Affiliation(s)
- Takahiro A Kato
- Department of Neuropsychiatry, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka 812-8582, Japan.
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Yang X, He G, Hao Y, Chen C, Li M, Wang Y, Zhang G, Yu Z. The role of the JAK2-STAT3 pathway in pro-inflammatory responses of EMF-stimulated N9 microglial cells. J Neuroinflammation 2010; 7:54. [PMID: 20828402 PMCID: PMC2945324 DOI: 10.1186/1742-2094-7-54] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 09/09/2010] [Indexed: 01/05/2023] Open
Abstract
Background In several neuropathological conditions, microglia can become overactivated and cause neurotoxicity by initiating neuronal damage in response to pro-inflammatory stimuli. Our previous studies have shown that exposure to electromagnetic fields (EMF) activates cultured microglia to produce tumor necrosis factor (TNF)-α and nitric oxide (NO) through signal transduction involving the activator of transcription STAT3. Here, we investigated the role of STAT3 signaling in EMF-induced microglial activation and pro-inflammatory responses in more detail than the previous study. Methods N9 microglial cells were treated with EMF exposure or a sham treatment, with or without pretreatment with an inhibitor (Pyridone 6, P6) of the Janus family of tyrosine kinases (JAK). The activation state of microglia was assessed via immunoreaction using the microglial marker CD11b. Levels of inducible nitric oxide synthase (iNOS), TNF-α and NO were measured using real-time reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and the nitrate reductase method. Activation of JAKs and STAT3 proteins was evaluated by western blotting for specific tyrosine phosphorylation. The ability of STAT3 to bind to DNA was detected with an electrophoresis mobility shift assay (EMSA). Results EMF was found to significantly induce phosphorylation of JAK2 and STAT3, and DNA-binding ability of STAT3 in N9 microglia. In addition, EMF dramatically increased the expression of CD11b, TNF-α and iNOS, and the production of NO. P6 strongly suppressed the phosphorylation of JAK2 and STAT3 and diminished STAT3 activity in EMF-stimulated microglia. Interestingly, expression of CD11b as well as gene expression and production of TNF-α and iNOS were suppressed by P6 at 12 h, but not at 3 h, after EMF exposure. Conclusions EMF exposure directly triggers initial activation of microglia and produces a significant pro-inflammatory response. Our findings confirm that the JAK2-STAT3 pathway may not mediate this initial microglial activation but does promote pro-inflammatory responses in EMF-stimulated microglial cells. Thus, the JAK2-STAT3 pathway might be a therapeutic target for reducing pro-inflammatory responses in EMF-activated microglia.
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Affiliation(s)
- Xuesen Yang
- Key Laboratory of Medical Protection for Electromagnetic Radiation Ministry of Education, Third Military Medical University, Chongqing, China
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Abstract
Innate immunity, with macrophages playing a central role, is critically important in the pathogenesis of RA. Although environmental insults such as smoking have been implicated in the initiation of rheumatoid arthritis (RA) in patients who express the shared epitope, the understanding of the role of innate immunity in the pathogenesis of this disease is also expanding. As the understanding continues to expand, enticing targets for new therapeutic interventions continue to be identified. This article focuses on cells of myelomonocytic origin, their receptors, and factors that interact with them.
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Affiliation(s)
- Angelica Gierut
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, 240 East Huron Street, McGaw M300, Chicago, IL 60611, USA
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Robust uptake of magnetic nanoparticles (MNPs) by central nervous system (CNS) microglia: implications for particle uptake in mixed neural cell populations. Int J Mol Sci 2010; 11:967-981. [PMID: 20479995 PMCID: PMC2869227 DOI: 10.3390/ijms11030967] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 03/02/2010] [Accepted: 03/04/2010] [Indexed: 01/16/2023] Open
Abstract
Magnetic nanoparticles (MNPs) are important contrast agents used to monitor a range of neuropathological processes; microglial cells significantly contribute to MNP uptake in sites of pathology. Microglial activation occurs following most CNS pathologies but it is not known if such activation alters MNP uptake, intracellular processing and toxicity. We assessed these parameters in microglial cultures with and without experimental ‘activation’. Microglia showed rapid and extensive MNP uptake under basal conditions with no changes found following activation; significant microglial toxicity was observed at higher particle concentrations. Based on our findings, we suggest that avid MNP uptake by endogenous CNS microglia could significantly limit uptake by other cellular subtypes in mixed neural cell populations.
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Kong T, Choi JK, Park H, Choi BH, Snyder BJ, Bukhari S, Kim NK, Huang X, Park SR, Park HC, Ha Y. Reduction in programmed cell death and improvement in functional outcome of transient focal cerebral ischemia after administration of granulocyte-macrophage colony-stimulating factor in rats. Laboratory investigation. J Neurosurg 2009; 111:155-63. [PMID: 19361262 DOI: 10.3171/2008.12.jns08172] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent hematopoietic growth factor that both enhances the survival and drives the differentiation and proliferation of myeloid lineage cells. Recent studies have suggested that GM-CSF has a neuroprotective effect against CNS injury. In this paper, the authors investigated the neuroprotective effect of GM-CSF on neuron survival and locomotor behavior in a rat model of focal cerebral ischemic injury. MATERIALS To understand its neuroprotective effect in vitro, GM-CSF was administered to a glutamate-induced excitotoxicity neuronal injury cell culture model that mimics the pathophysiology of focal hypoxic cerebral injury. In the animal study, the authors prepared a rat focal cerebral ischemia model by occluding the unilateral middle cerebral artery. They then examined the effects of GM-CSF administration on changes in infarct volume, apoptosis-related gene expression, and improvement in locomotor behavior. RESULTS Treatment with GM-CSF significantly increased cell viability in a cell culture model of glutamate-induced neuronal injury. Furthermore, in vivo administration of GM-CSF at 60 microg/kg body weight daily for 5 consecutive days beginning immediately after injury decreased infarction volume, altered the expression of several apoptosis-related genes (Bcl-2, Bax, caspase 3, and p53), and improved locomotor behavior in the focal cerebral ischemia model. CONCLUSIONS The GM-CSF had neuroprotective effects in in vitro and in vivo experiments and resulted in decreased infarction volume and improved locomotor behavior. Although the specific mechanism involved in stroke recovery was not fully elucidated as it was not the primary focus of this study, administration of GM-CSF appeared to decrease the extent of neuronal apoptosis by modulating the expression of several apoptosis-related genes such as Bcl-2, Bax, caspase 3, and p53. Further investigations are necessary to better understand the role of GM-CSF on neural regeneration during the recovery phase of a stroke, as well as the intracellular signal transduction pathways that mediate neuroprotection.
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Affiliation(s)
- TaeHo Kong
- Cell Therapy Research Center, Department of Physiology, School of Medicine, Inha University, Incheon, Korea
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Hamilton JA, Tak PP. The dynamics of macrophage lineage populations in inflammatory and autoimmune diseases. ACTA ACUST UNITED AC 2009; 60:1210-21. [PMID: 19404968 DOI: 10.1002/art.24505] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- John A Hamilton
- Arthritis and Inflammation Research Centre, University of Melbourne and Department of Medicine, The Royal Melbourne Hospital, Parkville, Victoria, Australia.
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Schallenberg M, Charalambous P, Thanos S. GM-CSF regulates the ERK1/2 pathways and protects injured retinal ganglion cells from induced death. Exp Eye Res 2009; 89:665-77. [PMID: 19560459 DOI: 10.1016/j.exer.2009.06.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 06/12/2009] [Accepted: 06/18/2009] [Indexed: 01/22/2023]
Abstract
Granulocyte-macrophage-colony-stimulating-factor (GM-CSF) is a potent hematopoietic cytokine. In the present study, we examined whether GM-CSF is neuroprotective in retinal ganglion cells (RGCs). First, we studied the expression of GM-CSF and the GM-CSF-alpha-receptor in rat and human retina and in RGC-5 cells. Then, RGC-5 cells were incubated with apoptosis-inducing agents (e.g., staurosporine, glutamate and NOR3). The cell death was assessed by Live-Death-Assays and apoptosis-related-proteins were examined by immunoblotting. In addition, the expression of phosphorylated ERK1/2-pathway-proteins after incubation with GM-CSF and after inhibiting MEK1/2 with U0126 was analyzed. To assess the in vivo-effect, first staurosporine or GM-CSF plus staurosporine was injected into the vitreous body of Sprague-Dawley rats. In a second axotomy model the optic nerve was cut and GM-CSF was injected into the vitreous body. In both models, the RGCs were labeled retrogradely with either Fluoro-Gold or 4-Di-10-Asp and counted. As a first result, we identified GM-CSF and the GM-CSF-alpha-receptor in rat and human retina as well as in RGC-5 cells. Then, in the RGC-5 cells GM-CSF counteracts induced cell death in a dose-and time-dependent manner. With respect to apoptosis, Western blot analysis revealed a decreased Bad-expression and an increased Bcl-2-expression after co-incubation with GM-CSF. Concerning signaling pathways, incubation with GM-CSF activates the ERK1/2 pathway, whereas inhibition of MEK1/2 with U0126 strongly decreased the phosphorylation downstream in the ERK1/2 pathway, and the antiapoptotic activity of GM-CSF in vitro. Like in vitro, GM-CSF counteracts the staurosporine-induced cell death in vivo and protects RGCs from axotomy-induced degeneration. Our data suggest that GM-CSF might be a novel therapeutic agent in neuropathic disease of the eye.
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Affiliation(s)
- Maurice Schallenberg
- Department of Experimental Ophthalmology, School of Medicine, University Eye Hospital Münster and Interdisciplinary Centre for Clinical Research (IZKF), Domagkstrasse 15, D-48149 Münster, Germany
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Qian L, Wei SJ, Zhang D, Hu X, Xu Z, Wilson B, El-Benna J, Hong JS, Flood PM. Potent anti-inflammatory and neuroprotective effects of TGF-beta1 are mediated through the inhibition of ERK and p47phox-Ser345 phosphorylation and translocation in microglia. THE JOURNAL OF IMMUNOLOGY 2008; 181:660-8. [PMID: 18566433 DOI: 10.4049/jimmunol.181.1.660] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TGF-beta1 is one of the most potent endogenous immune modulators of inflammation. The molecular mechanism of its anti-inflammatory effect on the activation of the transcription factor NF-kappaB has been well-studied; however, the potential effects of TGF-beta1 on other proinflammatory signaling pathways is less clear. In this study, using the well-established LPS and the 1-methyl-4-phenylpyridinium-mediated models of Parkinson's disease, we demonstrate that TGF-beta1 exerts significant neuroprotection in both models via its anti-inflammatory properties. The neuroprotective effects of TGF-beta1 are mainly attributed to its ability to inhibit the production of reactive oxygen species from microglia during their activation or reactivation. Moreover, we demonstrate that TGF-beta1 inhibited LPS-induced NADPH oxidase (PHOX) subunit p47phox translocation from the cytosol to the membrane in microglia within 10 min. Mechanistic studies show that TGF-beta1 fails to protect dopaminergic neurons in cultures from PHOX knockout mice, and significantly reduced LPS-induced translocation of the PHOX cytosolic subunit p47phox to the cell membrane. In addition, LPS-induced ERK phosphorylation and subsequent Ser345 phosphorylation on p47phox were significantly inhibited by TGF-beta1 pretreatment. Taken together, our results show that TGF-beta1 exerted potent anti-inflammatory and neuroprotective properties, either through the prevention of the direct activation of microglia by LPS, or indirectly through the inhibition of reactive microgliosis elicited by 1-methyl-4-phenylpyridinium. The molecular mechanisms of TGF-beta1-mediated anti-inflammatory properties is through the inhibition of PHOX activity by preventing the ERK-dependent phosphorylation of Ser345 on p47phox in microglia to reduce oxidase activities induced by LPS.
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Affiliation(s)
- Li Qian
- Comprehensive Center for Inflammatory Disorders, University of North Carolina, Chapel Hill, NC 27599-7455, USA
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Squamosamide derivative FLZ protects dopaminergic neurons against inflammation-mediated neurodegeneration through the inhibition of NADPH oxidase activity. J Neuroinflammation 2008; 5:21. [PMID: 18507839 PMCID: PMC2413210 DOI: 10.1186/1742-2094-5-21] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 05/28/2008] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Inflammation plays an important role in the pathogenesis of Parkinson's disease (PD) through over-activation of microglia, which consequently causes the excessive production of proinflammatory and neurotoxic factors, and impacts surrounding neurons and eventually induces neurodegeneration. Hence, prevention of microglial over-activation has been shown to be a prime target for the development of therapeutic agents for inflammation-mediated neurodegenerative diseases. METHODS For in vitro studies, mesencephalic neuron-glia cultures and reconstituted cultures were used to investigate the molecular mechanism by which FLZ, a squamosamide derivative, mediates anti-inflammatory and neuroprotective effects in both lipopolysaccharide-(LPS)- and 1-methyl-4-phenylpyridinium-(MPP+)-mediated models of PD. For in vivo studies, a 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine-(MPTP-) induced PD mouse model was used. RESULTS FLZ showed potent efficacy in protecting dopaminergic (DA) neurons against LPS-induced neurotoxicity, as shown in rat and mouse primary mesencephalic neuronal-glial cultures by DA uptake and tyrosine hydroxylase (TH) immunohistochemical results. The neuroprotective effect of FLZ was attributed to a reduction in LPS-induced microglial production of proinflammatory factors such as superoxide, tumor necrosis factor-alpha (TNF-alpha), nitric oxide (NO) and prostaglandin E2 (PGE2). Mechanistic studies revealed that the anti-inflammatory properties of FLZ were mediated through inhibition of NADPH oxidase (PHOX), the key microglial superoxide-producing enzyme. A critical role for PHOX in FLZ-elicited neuroprotection was further supported by the findings that 1) FLZ's protective effect was reduced in cultures from PHOX-/- mice, and 2) FLZ inhibited LPS-induced translocation of the cytosolic subunit of p47PHOX to the membrane and thus inhibited the activation of PHOX. The neuroprotective effect of FLZ demonstrated in primary neuronal-glial cultures was further substantiated by an in vivo study, which showed that FLZ significantly protected against MPTP-induced DA neuronal loss, microglial activation and behavioral changes. CONCLUSION Taken together, our results clearly demonstrate that FLZ is effective in protecting against LPS- and MPTP-induced neurotoxicity, and the mechanism of this protection appears to be due, at least in part, to inhibition of PHOX activity and to prevention of microglial activation.
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Increased in vivo activation of microglia and astrocytes in the brains of mice transgenic for an infectious R5 human immunodeficiency virus type 1 provirus and for CD4-specific expression of human cyclin T1 in response to stimulation by lipopolysaccharides. J Virol 2008; 82:5562-72. [PMID: 18353948 DOI: 10.1128/jvi.02618-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Inflammatory mediators and viral products produced by human immunodeficiency virus (HIV)-infected microglia and astrocytes perturb the function and viability of adjacent uninfected neuronal and glial cells and contribute to the pathogenesis of HIV-associated neurocognitive disorders (HAND). In vivo exposure to lipopolysaccharide (LPS) activates parenchymal microglia and astrocytes and induces cytokine and chemokine production in the brain. HIV-infected individuals display increased circulating LPS levels due to microbial translocation across a compromised mucosa barrier. We hypothesized that HIV-infected microglia and astrocytes display increased sensitivity to the proinflammatory effects of LPS, and this combines with the increased levels of systemic LPS in HIV-infected individuals to contribute to the development of HAND. To examine this possibility, we determined the in vivo responsiveness of HIV-infected microglia and astrocytes to LPS using our mouse model, JR-CSF/human cyclin T1 (JR-CSF/hu-cycT1) mice, which are transgenic for both an integrated full-length infectious HIV type 1 (HIV-1) provirus derived from the primary R5-tropic clinical isolate HIV-1(JR-CSF) regulated by the endogenous HIV-1 long terminal repeat and the hu-cycT1 gene under the control of a CD4 promoter. In the current report, we demonstrated that in vivo-administered LPS more potently activated JR-CSF/hu-cycT1 mouse microglia and astrocytes and induced a significantly higher degree of monocyte chemoattractant protein production by JR-CSF/hu-cycT1 astrocytes compared to that of the in vivo LPS response of control littermate mouse microglia and astrocytes. These results indicate that HIV infection increases the sensitivity of microglia and astrocytes to inflammatory stimulation and support the use of these mice as a model to investigate various aspects of the in vivo mechanism of HIV-induced neuronal dysfunction.
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Qian L, Tan KS, Wei SJ, Wu HM, Xu Z, Wilson B, Lu RB, Hong JS, Flood PM. Microglia-Mediated Neurotoxicity Is Inhibited by Morphine through an Opioid Receptor-Independent Reduction of NADPH Oxidase Activity. THE JOURNAL OF IMMUNOLOGY 2007; 179:1198-209. [PMID: 17617613 DOI: 10.4049/jimmunol.179.2.1198] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent studies have shown that morphine modulates the function of glia cells through both opioid receptor dependent and independent mechanisms. However, the mechanism by which morphine regulates neuronal disorders through the alteration of microglia activity remains unclear. In this study, using rat primary mesencephalic neuron-glia cultures, we report that both l-morphine and its synthetic stereoenantiomer, d-morphine, an ineffective opioid receptor agonist, significantly reduced LPS- or 1-methyl-4-phenylpyridinium-induced dopaminergic neurotoxicity with similar efficacy, indicating a nonopioid receptor-mediated effect. In addition, using reconstituted neuron and glia cultures, subpicomolar concentrations of morphine were found to be neuroprotective only in the presence of microglia, and significantly inhibited the production of inflammatory mediators from LPS-stimulated microglia cells. Mechanistic studies showed that both l- and d- morphine failed to protect dopaminergic neurons in cultures from NADPH oxidase (PHOX) knockout mice and significantly reduced LPS-induced PHOX cytosolic subunit p47(phox) translocation to the cell membrane by inhibiting ERK phosphorylation. Taken together, our results demonstrate that morphine, even at subpicomolar concentrations, exerts potent anti-inflammatory and neuroprotective effects either through the inhibition of direct microglial activation by LPS or through the inhibition of reactive microgliosis elicited by 1-methyl-4-phenylpyridinium. Furthermore, our study reveals that inhibition of PHOX is a novel site of action for the mu-opioid receptor-independent effect of morphine.
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Affiliation(s)
- Li Qian
- Comprehensive Center for Inflammatory Disorders, University of North Carolina, Chapel Hill, NC 27599, USA
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Echeverry S, Shi XQ, Zhang J. Characterization of cell proliferation in rat spinal cord following peripheral nerve injury and the relationship with neuropathic pain. Pain 2007; 135:37-47. [PMID: 17560721 DOI: 10.1016/j.pain.2007.05.002] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 04/10/2007] [Accepted: 05/01/2007] [Indexed: 10/23/2022]
Abstract
Glial activation is a typical response of the central nervous system to nerve injury. In the current investigation, we characterized the temporal and spatial pattern of glial proliferation, one of the most conspicuous features of glial activation, in relation to nerve injury-induced neuropathic pain. Using bromodeoxyuridine (BrdU) as a mitotic marker, we analyzed cell proliferation in the spinal cord, identified the phenotype of dividing cells, traced their fate, and correlated these phenomena with behavioural assays of the neuropathic pain syndrome. Our results demonstrated that peripheral nerve injury induced an early and transient cell proliferation, on the spinal cord ipsilateral to the nerve lesion which peaked at day 3 post-surgery. The majority of the proliferating cells were Iba-1(+) microglia, together with some NG2(+) oligodendrocyte progenitors, and GFAP(+) astrocytes. These newly generated cells continued to divide over time with the response peaking at day 14 post-injury. Microglia were always the predominant phenotype which made up over 60% of activated microglia derived from this newly generated cell population. There was a close temporal correlation between microglial proliferation in the spinal cord dorsal horn and the abnormal pain responses, suggesting a contribution of the new microglia to the genesis of the neuropathic pain symptoms.
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Affiliation(s)
- Stefania Echeverry
- Unité de Neurobiologie Cellulaire, Centre de Recherche Université Laval Robert-Giffard, Université Laval, 2601, Chemin de la Canardière, Québec, Canada
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Gingras M, Gagnon V, Minotti S, Durham HD, Berthod F. Optimized protocols for isolation of primary motor neurons, astrocytes and microglia from embryonic mouse spinal cord. J Neurosci Methods 2007; 163:111-8. [PMID: 17445905 DOI: 10.1016/j.jneumeth.2007.02.024] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 02/08/2007] [Accepted: 02/27/2007] [Indexed: 10/23/2022]
Abstract
Neuron-glial interactions are important in development of the nervous system and pathogenesis of disease. Primary cell cultures prepared from nervous tissue are often used to study the properties of individual cell types and how they interact with each other. Isolation of pure populations of cells and their culture is challenging, particularly from murine spinal cord. The purpose of this study was to optimize various protocols to achieve efficient, parallel isolation and purification of primary motor neurons, microglia and astrocytes from the same mouse embryonic spinal cord sample. Following dissociation of E12 embryonic spinal cords, motor neurons were isolated at 97% purity by a single step centrifugation of the cell suspension through multiple discontinuous density gradients of NycoPrep. The residual mixed cell pellet was resuspended and cultured for 2 weeks. Mixed cultures were then shaken to release microglia, which were then harvested from the medium and subjected to another round of differential adhesion to achieve 99% purity. The astrocytes remaining in the mixed cultures were culled to 98% purity by treatment with leucine methyl ester and a subsequent vigorous shaking step to remove any remaining microglia and neurons. Furthermore, no cross contamination was observed in the glial cultures. This technique provides a simple, convenient, and reliable method of obtaining highly purified preparations of motor neurons, microglia and astrocytes from embryonic spinal cord for the study of spinal cord cell biology and motor neuron diseases.
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Affiliation(s)
- Marie Gingras
- Laboratoire d'Organogénèse Expérimentale (LOEX), Centre hospitalier affilié universitaire de Québec, Hôpital du Saint-Sacrement and Département de chirurgie, Faculté de médecine, Université Laval, Québec, Canada G1S 4L8
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Deboy CA, Xin J, Byram SC, Serpe CJ, Sanders VM, Jones KJ. Immune-mediated neuroprotection of axotomized mouse facial motoneurons is dependent on the IL-4/STAT6 signaling pathway in CD4+ T cells. Exp Neurol 2006; 201:212-24. [PMID: 16806176 DOI: 10.1016/j.expneurol.2006.04.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2005] [Revised: 03/13/2006] [Accepted: 04/05/2006] [Indexed: 12/12/2022]
Abstract
The CD4(+) T lymphocyte has recently been found to promote facial motoneuron (FMN) survival after nerve injury. Signal Transducer and Activator of Transcription (STAT)4 and STAT6 are key proteins involved in the CD4(+) T cell differentiation pathways leading to T helper type (Th)1 and Th2 cell development, respectively. To determine which CD4(+) T cell subset mediates FMN survival, the facial nerve axotomy paradigm was applied to STAT4-deficient (-/-) and STAT6-/- mice. A significant decrease in FMN survival 4 weeks after axotomy was observed in STAT6-/- mice compared to wild-type (WT) or STAT4-/- mice. Reconstituting STAT6-/- mice with CD4(+) T cells obtained from WT mice promoted WT levels of FMN survival after injury. Furthermore, rescue of FMN from axotomy-induced cell death in recombination activating gene (RAG)-2-/- mice (lacking T and B cells) could be achieved only by reconstitution with CD4(+) T cells expressing functional STAT6 protein. To determine if either the Th1 cytokine, interferon-gamma (IFN-gamma) or the Th2 cytokine IL-4 is involved in mediating FMN survival, facial nerve axotomy was applied to IFN-gamma-/- and IL-4-/- mice. A significant decrease in FMN survival after axotomy occurred in IL-4-/- but not in IFN-gamma-/- mice compared to WT mice, indicating that IL-4 but not IFN-gamma is important for FMN survival after nerve injury. In WT mice, intracellular IFN-gamma vs. IL-4 expression was examined in CD4(+) T cells from draining cervical lymph nodes 14 days after axotomy, and substantial increase in the production of both CD4(+) effector T cell subsets was found. Collectively, these data suggest that STAT6-mediated CD4(+) T cell differentiation into the Th2 subset is necessary for FMN survival. A hypothesis relevant to motoneuron disease progression is presented.
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Affiliation(s)
- Cynthia A Deboy
- Department of Cell Biology, Neurobiology, and Anatomy, Loyola University Chicago, 2160 S. 1st Avenue, Maywood, IL 60153, USA.
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Qian L, Block ML, Wei SJ, Lin CF, Reece J, Pang H, Wilson B, Hong JS, Flood PM. Interleukin-10 protects lipopolysaccharide-induced neurotoxicity in primary midbrain cultures by inhibiting the function of NADPH oxidase. J Pharmacol Exp Ther 2006; 319:44-52. [PMID: 16807359 DOI: 10.1124/jpet.106.106351] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of anti-inflammatory cytokines in Parkinson's disease is not completely understood. In this study, using mesencephalic neuron-glia cultures, we report that both pretreatment and post-treatment of rat mesencephalic neuron-glia cultures with interleukin (IL)-10, a natural immune modulator, reduced lipopolysaccharide (LPS)-induced DA neurotoxicity. The main purpose of this study was to elucidate the molecular mechanism underlying IL-10-elicited neuroprotection. IL-10 significantly inhibited LPS-induced production of tumor necrosis factor-alpha, nitric oxide, and extracellular superoxide in microglia cells. In addition, using reconstituted neuron and glia cell cultures, IL-10 was shown to be neuroprotective only in the presence of microglia. More importantly, IL-10 failed to protect DA neurons in cultures from mice lacking NADPH oxidase (PHOX), a key enzyme for extracellular superoxide production in immune cells, suggesting the critical role of PHOX in IL-10 neuroprotection. This conclusion was further supported by the finding that IL-10 inhibited LPS-induced translocation of the cytosolic subunit of NADPH oxidase p47(phox) to the membrane. When the Janus tyrosine kinase (JAK) 1 signaling pathway was blocked, IL-10 failed to attenuate LPS-induced superoxide production, indicating that the JAK1 signaling cascade mediates the inhibitory effect of IL-10. Together, our results suggest that IL-10 inhibits LPS-induced DA neurotoxicity through the inhibition of PHOX activity in a JAK1-dependent mechanism.
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Affiliation(s)
- Li Qian
- The Comprehensive Center for Inflammatory Disorders, University of North Carolina, Chapel Hill, NC 27599-7455, USA
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Mander PK, Jekabsone A, Brown GC. Microglia proliferation is regulated by hydrogen peroxide from NADPH oxidase. THE JOURNAL OF IMMUNOLOGY 2006; 176:1046-52. [PMID: 16393992 DOI: 10.4049/jimmunol.176.2.1046] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Microglia are resident brain macrophages that become activated and proliferate following brain damage or stimulation by immune mediators, such as IL-1beta or TNF-alpha. We investigated the mechanisms by which microglial proliferation is regulated in primary cultures of rat glia. We found that basal proliferation of microglia was stimulated by proinflammatory cytokines IL-1beta or TNF-alpha, and this proliferation was completely inhibited by catalase, implicating hydrogen peroxide as a mediator of proliferation. In addition, inhibitors of NADPH oxidase (diphenylene iodonium or apocynin) also prevented microglia proliferation, suggesting that this may be the source of hydrogen peroxide. IL-1beta and TNF-alpha rapidly stimulated the rate of hydrogen peroxide produced by isolated microglia, and this was inhibited by diphenylene iodonium, implying that the cytokines were acting directly on microglia to stimulate the NADPH oxidase. Low concentrations of PMA or arachidonic acid (known activators of NADPH oxidase) or xanthine/xanthine oxidase or glucose oxidase (generating hydrogen peroxide) also increased microglia proliferation and this was blocked by catalase, showing that NADPH oxidase activation or hydrogen peroxide was sufficient to stimulate microglia proliferation. In contrast to microglia, the proliferation of astrocytes was unaffected by the presence of catalase. In conclusion, these findings indicate that microglial proliferation in response to IL-1beta or TNF-alpha is mediated by hydrogen peroxide from NADPH oxidase.
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Affiliation(s)
- Palwinder K Mander
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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Rodriguez M, Zoecklein L, Gamez JD, Pavelko KD, Papke LM, Nakane S, Howe C, Radhakrishnan S, Hansen MJ, David CS, Warrington AE, Pease LR. STAT4- and STAT6-signaling molecules in a murine model of multiple sclerosis. FASEB J 2005; 20:343-5. [PMID: 16352646 DOI: 10.1096/fj.05-4650fje] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Epidemiological studies suggest that an environmental factor (possibly a virus) acquired early in life may trigger multiple sclerosis (MS). The virus may remain dormant in the central nervous system but then becomes activated in adulthood. All existing models of MS are characterized by inflammation or demyelination that follows days after virus infection or antigen inoculation. While investigating the role of CD4+ T cell responses following Theiler's virus infection in mice deficient in STAT4 or STAT6, we discovered a model in which virus infection was followed by demyelination after a very prolonged incubation period. STAT4-/- mice were resistant to demyelination for 180 days after infection, but developed severe demyelination after this time point. Inflammatory cells and up-regulation of Class I and Class II MHC antigens characterized these lesions. Virus antigen was partially controlled during the early chronic phase of the infection even though viral RNA levels remained high throughout infection. Demyelination correlated with the appearance of virus antigen expression. Bone marrow reconstitution experiments indicated that the mechanism of the late onset demyelination was the result of the STAT4-/- immune system. Thus, virus infection of STAT4-/- mice results in a model that may allow for dissection of the immune events predisposing to late-onset demyelination in MS.
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Affiliation(s)
- Moses Rodriguez
- Department of Neurology, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Nasu-Tada K, Koizumi S, Inoue K. Involvement of beta1 integrin in microglial chemotaxis and proliferation on fibronectin: different regulations by ADP through PKA. Glia 2005; 52:98-107. [PMID: 15920726 DOI: 10.1002/glia.20224] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Microglia are immune cells in the brain; their activation, migration, and proliferation have pivotal roles in brain injuries and diseases. Microglia are known to attach firmly to fibronectin, the upregulation of which is associated with several pathological conditions in the CNS, through beta1 integrin and become activated. Extracellular nucleotides can serve as potent signaling molecules. Recently, ATP and ADP were revealed to possess chemoattractive properties to microglia via Gi-coupled P2Y receptors. In the present study, we report that the ADP-induced chemotaxis of microglia is mediated by P2Y12/13 receptors and is beta1 integrin-dependent in the presence of fibronectin. Signals from P2Y12/13 receptors also cause beta1 integrin translocation to the membrane ruffle regions, but this redistribution was lost when the intracellular cyclic AMP (cAMP) was increased by forskolin or dibutyryl cAMP. This inhibitory effect of cAMP-elevating agents did not appear when microglia were co-incubated with a protein kinase A (PKA) inhibitor, KT-5720, suggesting that PKA is a negative regulator of the beta1 integrin translocation. We also show that the engagement of beta1 integrin enhanced microglial proliferation. Signals from P2Y12/13 receptors attenuated the proliferation, whereas ADP itself had no effect on microglial growth. Furthermore, beta1 integrin-induced proliferation is positively regulated by the cAMP-dependent PKA. Together, these results indicate the involvement of beta1 integrin in microglial proliferation and chemotaxis, both of which have clinical importance. The data also suggest that PKA is inversely involved in these two cellular functions.
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Affiliation(s)
- Kaoru Nasu-Tada
- Division of Pharmacology, National Institute of Health Sciences, Setagaya, Tokyo, Japan
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Chien HF, Yeh KY, Jiang-Shieh YF, Wei IH, Chang CY, Chang ML, Wu CH. Signal transduction pathways of nitric oxide release in primary microglial culture challenged with gram-positive bacterial constituent, lipoteichoic acid. Neuroscience 2005; 133:423-36. [PMID: 15878805 DOI: 10.1016/j.neuroscience.2004.09.067] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Revised: 08/25/2004] [Accepted: 09/17/2004] [Indexed: 11/16/2022]
Abstract
Between one-third and one-half of all cases of sepsis are known to be caused by gram-positive microorganisms through the cell wall component, e.g. lipoteichoic acid (LTA). Gram-positive bacteria are also known to induce encephalomyelitis and meningeal inflammation, and enhance the production of nitric oxide (NO) via expression of inducible nitric oxide synthase (iNOS) in murine tissue macrophages. It remains to be explored if LTA could activate microglia considered to be resident brain macrophages. We report here that LTA derived from gram-positive bacteria (Staphylococcus aureus) significantly induces NO release and iNOS expression in primary microglia. LTA-induced NO accumulation was detected at 2 h in microglial culture and was significantly attenuated by pretreatment with anti-CD14, complement receptor type 3 (CR3) or scavenger receptor (SR) antibodies. LTA activated mitogen-activated protein kinases (MAPKs) such as extracellular signal-regulated kinase, p38 MAPK or c-Jun N-terminal kinase in cultured microglia. LTA-elicited microglial NO production was also drastically suppressed by SB203580 (p38 MAPK inhibitor) or pyrrolidine dithiocarbamate (an inhibitor of nuclear factor kappaB), indicating that p38 MAPK and nuclear factor kappaB were involved in microglial NO release after LTA challenge. These results suggest that gram-positive bacterial product such as LTA can activate microglia to release NO via the signal transduction pathway involving multiple LTA receptors (e.g. CD14, CR3 or SR), p38 MAPK and nuclear factor kappaB. The in vivo study further confirmed that administered intracerebrally LTA induced considerable noticeable iNOS, phospho-IkappaB and phospho-p38 MAPK expression in microglia/macrophages.
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Affiliation(s)
- H F Chien
- Department of Surgery, College of Medicine, National Taiwan University, 1, Section 1, Jen-Ai Road, Taipei 100, Taiwan
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