1
|
Sun Y, Sun W, Liu J, Zhang B, Zheng L, Zou W. The dual role of microglia in intracerebral hemorrhage. Behav Brain Res 2024; 473:115198. [PMID: 39128628 DOI: 10.1016/j.bbr.2024.115198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 07/05/2024] [Accepted: 08/09/2024] [Indexed: 08/13/2024]
Abstract
Intracerebral hemorrhage has the characteristics of high morbidity, disability and mortality, which has caused a heavy burden to families and society. Microglia are resident immune cells in the central nervous system, and their activation plays a dual role in tissue damage after intracerebral hemorrhage. The damage in cerebral hemorrhage is embodied in the following aspects: releasing inflammatory factors and inflammatory mediators, triggering programmed cell death, producing glutamate induced excitotoxicity, and destroying blood-brain barrier; The protective effect is reflected in the phagocytosis and clearance of harmful substances by microglia, and the secretion of anti-inflammatory and neurotrophic factors. This article summarizes the function of microglia and its dual regulatory mechanism in intracerebral hemorrhage. In the future, drugs, acupuncture and other clinical treatments can be used to intervene in the activation state of microglia, so as to reduce the harm of microglia.
Collapse
Affiliation(s)
- Yue Sun
- Heilongjiang University of Chinese Medicine, Harbin 150040, Heilongjiang, China
| | - Wentao Sun
- Faculty of Chinese Medicine Sciense guangxi university of chinese medicine; Nanning city 530000, Guangxi, China
| | - Jiawei Liu
- Heilongjiang University of Chinese Medicine, Harbin 150040, Heilongjiang, China
| | - Baiwen Zhang
- Clinical Key Laboratory of Integrated Traditional Chinese and Western Medicine of Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Lei Zheng
- Clinical Key Laboratory of Integrated Traditional Chinese and Western Medicine of Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Wei Zou
- The First Affiliated Hospital of Heilongjiang University of Chinese Medicine,Harbin 150040, Heilongjiang, China.
| |
Collapse
|
2
|
Sezginer O, Unver N. Dissection of pro-tumoral macrophage subtypes and immunosuppressive cells participating in M2 polarization. Inflamm Res 2024:10.1007/s00011-024-01907-3. [PMID: 38935134 DOI: 10.1007/s00011-024-01907-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 06/06/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024] Open
Abstract
Alternatively activated macrophage (M2) polarization can result in one of four subtypes based on cytokines and signaling pathways associated with macrophage activation: M2a, M2b, M2c, and M2d macrophages. The majority of M2 subtypes are anti-inflammatory and pro-angiogenic, secreting growth factors (VEGF, PDGF) and matrix metalloproteinases (MMP2, MMP9) which boost tumor growth, metastasis, and invasion. M2-polarized macrophages are associated with immune suppressor cells harboring Myeloid derived suppressor cells, Regulatory T cells (Tregs), Regulatory B cells as well as alternatively activated (N2) neutrophils. Treg cells selectively support the metabolic stability, mitochondrial integrity, and survival rate of M2-like TAMs in an indirect environment. Also, the contribution of Breg cells influences macrophage polarization towards the M2 direction. TAM is activated when TAN levels in the tumor microenvironment are insufficient or vice versa, suggesting that macrophage and its polarization are fine-tuned. Understanding the functions of immune suppressive cells, mediators, and signaling pathways involved with M2 polarization will allow us to identify potential strategies for targeting the TAM repolarization phenotype for innovative immunotherapy approaches. In this review, we have highlighted the critical factors for M2 macrophage polarization, differential cytokine/chemokine profiles of M1 and M2 macrophage subtypes, and other immune cells' impact on the polarization within the immunosuppressive niche.
Collapse
Affiliation(s)
- Onurcan Sezginer
- Department of Basic Oncology, Cancer Institute, Hacettepe University, Sihhiye, Ankara, 06100, Türkiye
| | - Nese Unver
- Department of Basic Oncology, Cancer Institute, Hacettepe University, Sihhiye, Ankara, 06100, Türkiye.
| |
Collapse
|
3
|
Quan H, Zhang R. Microglia dynamic response and phenotype heterogeneity in neural regeneration following hypoxic-ischemic brain injury. Front Immunol 2023; 14:1320271. [PMID: 38094292 PMCID: PMC10716326 DOI: 10.3389/fimmu.2023.1320271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 11/14/2023] [Indexed: 12/18/2023] Open
Abstract
Hypoxic-ischemic brain injury poses a significant threat to the neural niche within the central nervous system. In response to this pathological process, microglia, as innate immune cells in the central nervous system, undergo rapid morphological, molecular and functional changes. Here, we comprehensively review these dynamic changes in microglial response to hypoxic-ischemic brain injury under pathological conditions, including stroke, chronic intermittent hypoxia and neonatal hypoxic-ischemic brain injury. We focus on the regulation of signaling pathways under hypoxic-ischemic brain injury and further describe the process of microenvironment remodeling and neural tissue regeneration mediated by microglia after hypoxic-ischemic injury.
Collapse
Affiliation(s)
- Hongxin Quan
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| | - Runrui Zhang
- State Key Laboratory of Primate Biomedical Research, Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
- Yunnan Key Laboratory of Primate Biomedical Research, Kunming, Yunnan, China
| |
Collapse
|
4
|
Radpour M, Khoshkroodian B, Asgari T, Pourbadie HG, Sayyah M. Interleukin 4 Reduces Brain Hyperexcitability after Traumatic Injury by Downregulating TNF-α, Upregulating IL-10/TGF-β, and Potential Directing Macrophage/Microglia to the M2 Anti-inflammatory Phenotype. Inflammation 2023; 46:1810-1831. [PMID: 37259014 DOI: 10.1007/s10753-023-01843-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/14/2023] [Accepted: 05/16/2023] [Indexed: 06/02/2023]
Abstract
Macrophage/microglia are activated after Traumatic brain injury (TBI), transform to inflammatory phenotype (M1) and trigger neuroinflammation, which provokes epileptogenesis. Interleukin-4 (IL-4) is a well-known drive of macrophage/microglia to the anti-inflammatory phenotype (M2). We tested effect of IL-4 on speed of epileptogenesis, brain expression of inflammatory and anti-inflammatory cytokines, and lesion size in TBI-injured male rats. Rats underwent TBI by Controlled Cortical Impact. Then 100 ng IL-4 was injected into cerebral ventricles. One day after TBI, pentylenetetrazole (PTZ) kindling started and development of generalized seizures was recorded. The lesion size, cell survival rate, TNF-α, TGF-β, IL-10, and Arginase1 (Arg1) was measured in the brain 6 h, 12 h, 24 h, 48 h, and 5 days after TBI. Astrocytes and macrophage/microglia activation/polarization was assessed by GFAP/Arg1 and Iba1/Arg1 immunostaining. TBI-injured rats were kindled by 50% less PTZ injections than control and sham-operated rats. IL-4 did not change kindling rate in sham-operated rats but inhibited acceleration of kindling rate in the TBI-injured rats. IL-4 decreased damage volume and number of destroyed neurons. IL-4 stopped TNF-α whereas upregulated TGF-β, IL-10, and Arg1 expressions. Iba1/Arg1 positive macrophage/microglia was notably increased 48 h after IL-4 administration. IL-4 suppresses TBI-induced acceleration of epileptogenesis in rats by directing TBI neuroinflammation toward an anti-inflammatory tone and inhibition of cell death.
Collapse
Affiliation(s)
- Mozhdeh Radpour
- Department of Physiology and Pharmacology, Pasteur Institute of Iran , Tehran, Iran
| | - Bahar Khoshkroodian
- Department of Physiology and Pharmacology, Pasteur Institute of Iran , Tehran, Iran
| | - Tara Asgari
- Department of Physiology and Pharmacology, Pasteur Institute of Iran , Tehran, Iran
| | | | - Mohammad Sayyah
- Department of Physiology and Pharmacology, Pasteur Institute of Iran , Tehran, Iran.
| |
Collapse
|
5
|
Kuffler DP. Evolving techniques for reducing phantom limb pain. Exp Biol Med (Maywood) 2023; 248:561-572. [PMID: 37158119 PMCID: PMC10350801 DOI: 10.1177/15353702231168150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
At least two million people in the United States of America live with lost limbs, and the number is expected to double by 2050, although the incidence of amputations is significantly greater in other parts of the world. Within days to weeks of the amputation, up to 90% of these individuals develop neuropathic pain, presenting as phantom limb pain (PLP). The pain level increases significantly within one year and remains chronic and severe for about 10%. Amputation-induced changes are considered to underlie the causation of PLP. Techniques applied to the central nervous system (CNS) and peripheral nervous system (PNS) are designed to reverse amputation-induced changes, thereby reducing/eliminating PLP. The primary treatment for PLP is the administration of pharmacological agents, some of which are considered but provide no more than short-term pain relief. Alternative techniques are also discussed, which provide only short-term pain relief. Changes induced by various cells and the factors they release are required to change neurons and their environment to reduce/eliminate PLP. It is concluded that novel techniques that utilize autologous platelet-rich plasma (PRP) may provide long-term PLP reduction/elimination.
Collapse
Affiliation(s)
- Damien P Kuffler
- Institute of Neurobiology, Medical Sciences Campus, University of Puerto Rico, San Juan 00901, Puerto Rico
| |
Collapse
|
6
|
Russo C, Valle MS, Casabona A, Malaguarnera L. Chitinase Signature in the Plasticity of Neurodegenerative Diseases. Int J Mol Sci 2023; 24:ijms24076301. [PMID: 37047273 PMCID: PMC10094409 DOI: 10.3390/ijms24076301] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
Several reports have pointed out that Chitinases are expressed and secreted by various cell types of central nervous system (CNS), including activated microglia and astrocytes. These cells play a key role in neuroinflammation and in the pathogenesis of many neurodegenerative disorders. Increased levels of Chitinases, in particular Chitotriosidase (CHIT-1) and chitinase-3-like protein 1 (CHI3L1), have been found increased in several neurodegenerative disorders. Although having important biological roles in inflammation, to date, the molecular mechanisms of Chitinase involvement in the pathogenesis of neurodegenerative disorders is not well-elucidated. Several studies showed that some Chitinases could be assumed as markers for diagnosis, prognosis, activity, and severity of a disease and therefore can be helpful in the choice of treatment. However, some studies showed controversial results. This review will discuss the potential of Chitinases in the pathogenesis of some neurodegenerative disorders, such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and multiple sclerosis, to understand their role as distinctive biomarkers of neuronal cell activity during neuroinflammatory processes. Knowledge of the role of Chitinases in neuronal cell activation could allow for the development of new methodologies for downregulating neuroinflammation and consequently for diminishing negative neurological disease outcomes.
Collapse
Affiliation(s)
- Cristina Russo
- Section of Pathology, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| | - Maria Stella Valle
- Laboratory of Neuro-Biomechanics, Section of Physiology, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
- Correspondence:
| | - Antonino Casabona
- Laboratory of Neuro-Biomechanics, Section of Physiology, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| | - Lucia Malaguarnera
- Section of Pathology, Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, 95123 Catania, Italy
| |
Collapse
|
7
|
Sex-Specific Microglial Responses to Glucocerebrosidase Inhibition: Relevance to GBA1-Linked Parkinson's Disease. Cells 2023; 12:cells12030343. [PMID: 36766684 PMCID: PMC9913749 DOI: 10.3390/cells12030343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
Microglia are heterogenous cells characterized by distinct populations each contributing to specific biological processes in the nervous system, including neuroprotection. To elucidate the impact of sex-specific microglia heterogenicity to the susceptibility of neuronal stress, we video-recorded with time-lapse microscopy the changes in shape and motility occurring in primary cells derived from mice of both sexes in response to pro-inflammatory or neurotoxic stimulations. With this morpho-functional analysis, we documented distinct microglia subpopulations eliciting sex-specific responses to stimulation: male microglia tended to have a more pro-inflammatory phenotype, while female microglia showed increased sensitivity to conduritol-B-epoxide (CBE), a small molecule inhibitor of glucocerebrosidase, the enzyme encoded by the GBA1 gene, mutations of which are the major risk factor for Parkinson's Disease (PD). Interestingly, glucocerebrosidase inhibition particularly impaired the ability of female microglia to enhance the Nrf2-dependent detoxification pathway in neurons, attenuating the sex differences observed in this neuroprotective function. This finding is consistent with the clinical impact of GBA1 mutations, in which the 1.5-2-fold reduced risk of developing idiopathic PD observed in female individuals is lost in the GBA1 carrier population, thus suggesting a sex-specific role for microglia in the etiopathogenesis of PD-GBA1.
Collapse
|
8
|
Gao X, Cao Z, Tan H, Li P, Su W, Wan T, Guo W. LncRNA, an Emerging Approach for Neurological Diseases Treatment by Regulating Microglia Polarization. Front Neurosci 2022; 16:903472. [PMID: 35860297 PMCID: PMC9289270 DOI: 10.3389/fnins.2022.903472] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/06/2022] [Indexed: 12/12/2022] Open
Abstract
Neurological disorders cause untold human disability and death each year. For most neurological disorders, the efficacy of their primary treatment strategies remains suboptimal. Microglia are associated with the development and progression of multiple neurological disorders. Targeting the regulation of microglia polarization has emerged as an important therapeutic strategy for neurological disorders. Their pro-inflammatory (M1)/anti-inflammatory (M2) phenotype microglia are closely associated with neuronal apoptosis, synaptic plasticity, blood-brain barrier integrity, resistance to iron death, and astrocyte regulation. LncRNA, a recently extensively studied non-coding transcript of over 200 nucleotides, has shown great value to intervene in microglia polarization. It can often participate in gene regulation of microglia by directly regulating transcription or sponging downstream miRNAs, for example. Through proper regulation, microglia can exert neuroprotective effects, reduce neurological damage and improve the prognosis of many neurological diseases. This paper reviews the progress of research linking lncRNAs to microglia polarization and neurological diseases.
Collapse
Affiliation(s)
- Xiaoyu Gao
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Zilong Cao
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Haifeng Tan
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Peiling Li
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Wenen Su
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Teng Wan
- Sports Medicine Department, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
- Teng Wan,
| | - Weiming Guo
- Sports Medicine Department, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
- *Correspondence: Weiming Guo,
| |
Collapse
|
9
|
Experimental Arthritis Inhibits Adult Hippocampal Neurogenesis in Mice. Cells 2022; 11:cells11050791. [PMID: 35269413 PMCID: PMC8909078 DOI: 10.3390/cells11050791] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 02/01/2023] Open
Abstract
Background: Adult-born neurons of the hippocampal dentate gyrus play a role in specific forms of learning, and disturbed neurogenesis seems to contribute to the development of neuropsychiatric disorders, such as major depression. Neuroinflammation inhibits adult neurogenesis, but the effect of peripheral inflammation on this form of neuroplasticity is ambiguous. Objective: Our aim was to investigate the influence of acute and chronic experimental arthritis on adult hippocampal neurogenesis and to elucidate putative regulatory mechanisms. Methods: Arthritis was triggered by subcutaneous injection of complete Freund’s adjuvant (CFA) into the hind paws of adult male mice. The animals were killed either seven days (acute inflammation) or 21 days (chronic inflammation) after the CFA injection. Behavioral tests were used to demonstrate arthritis-related hypersensitivity to painful stimuli. We used in vivo bioluminescence imaging to verify local inflammation. The systemic inflammatory response was assessed by complete blood cell counts and by measurement of the cytokine/chemokine concentrations of TNF-α, IL-1α, IL-4, IL-6, IL-10, KC and MIP-2 in the inflamed hind limbs, peripheral blood and hippocampus to characterize the inflammatory responses in the periphery and in the brain. In the hippocampal dentate gyrus, the total number of newborn neurons was determined with quantitative immunohistochemistry visualizing BrdU- and doublecortin-positive cells. Microglial activation in the dentate gyrus was determined by quantifying the density of Iba1- and CD68-positive cells. Results: Both acute and chronic arthritis resulted in paw edema, mechanical and thermal hyperalgesia. We found phagocytic infiltration and increased levels of TNF-α, IL-4, IL-6, KC and MIP-2 in the inflamed hind paws. Circulating neutrophil granulocytes and IL-6 levels increased in the blood solely during the acute phase. In the dentate gyrus, chronic arthritis reduced the number of doublecortin-positive cells, and we found increased density of CD68-positive macrophages/microglia in both the acute and chronic phases. Cytokine levels, however, were not altered in the hippocampus. Conclusions: Our data suggest that acute peripheral inflammation initiates a cascade of molecular and cellular changes that eventually leads to reduced adult hippocampal neurogenesis, which was detectable only in the chronic inflammatory phase.
Collapse
|
10
|
Soares NL, Vieira HLA. Microglia at the Centre of Brain Research: Accomplishments and Challenges for the Future. Neurochem Res 2021; 47:218-233. [PMID: 34586585 DOI: 10.1007/s11064-021-03456-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 02/08/2023]
Abstract
Microglia are the immune guardians of the central nervous system (CNS), with critical functions in development, maintenance of homeostatic tissue balance, injury and repair. For a long time considered a forgotten 'third element' with basic phagocytic functions, a recent surge in interest, accompanied by technological progress, has demonstrated that these distinct myeloid cells have a wide-ranging importance for brain function. This review reports microglial origins, development, and function in the healthy brain. Moreover, it also targets microglia dysfunction and how it contributes to the progression of several neurological disorders, focusing on particular molecular mechanisms and whether these may present themselves as opportunities for novel, microglia-targeted therapeutic approaches, an ever-enticing prospect. Finally, as it has been recently celebrated 100 years of microglia research, the review highlights key landmarks from the past century and looked into the future. Many challenging problems have arisen, thus it points out some of the most pressing questions and experimental challenges for the ensuing century.
Collapse
Affiliation(s)
- Nuno L Soares
- Chronic Diseases Research Center (CEDOC) - Faculdade de Ciências Médicas/NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria 130, 1169-056, Lisboa, Portugal.
| | - Helena L A Vieira
- Chronic Diseases Research Center (CEDOC) - Faculdade de Ciências Médicas/NOVA Medical School, Universidade Nova de Lisboa, Campo dos Mártires da Pátria 130, 1169-056, Lisboa, Portugal.,Department of Chemistry, UCIBIO, Applied Molecular Biosciences Unit, NOVA School of Science and Technology, Universidade Nova de Lisboa, Lisboa, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, Lisboa, Portugal
| |
Collapse
|
11
|
The N-Formyl Peptide Receptor 2 (FPR2) Agonist MR-39 Exhibits Anti-Inflammatory Activity in LPS-Stimulated Organotypic Hippocampal Cultures. Cells 2021; 10:cells10061524. [PMID: 34204273 PMCID: PMC8235773 DOI: 10.3390/cells10061524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 01/25/2023] Open
Abstract
Accumulating evidence indicates a pivotal role for chronic inflammatory processes in the pathogenesis of neurodegenerative and psychiatric disorders. G protein-coupled formyl peptide receptor 2 (FPR2) mediates pro-inflammatory or anti-/pro-resolving effects upon stimulation with biased agonists. We aimed to evaluate the effects of a new FPR2 ureidopropanamide agonist, compound MR-39, on neuroinflammatory processes in organotypic hippocampal cultures (OHCs) derived from control (WT) and knockout FPR2−/− mice (KO) exposed to bacterial endotoxin (lipopolysaccharide; LPS). Higher LPS-induced cytokine expression and basal release were observed in KO FPR2 cultures than in WT cultures, suggesting that a lack of FPR2 enhances the OHCs response to inflammatory stimuli. Pretreatment with MR-39 abolished some of the LPS-induced changes in the expression of genes related to the M1/M2 phenotypes (including Il-1β, Il-6, Arg1, Il-4, Cd74, Fizz and Cx3cr1) and TNF-α, IL-1β and IL-4 release in tissue derived from WT but not KO mice. Receptor specificity was confirmed by adding the FPR2 antagonist WRW4, which abolished the abovementioned effects of MR-39. Further biochemical data showed an increase in the phospho-p65/total p65 ratio after LPS stimulation in hippocampal tissues from both WT and KO mice, and MR-39 only reversed this effect on WT OHCs. LPS also increased TRAF6 levels, which are critical for the TLR4-mediated NF-κB pro-inflammatory responses. MR-39 attenuated the LPS-evoked increase in the levels of the NLRP3 and caspase-1 proteins in WT but not KO hippocampal cultures. Since NLRP3 may be involved in the pyroptosis, a lytic type of programmed cell death in which the main role is played by Gasdermin D (GSDMD), we examined the effects of LPS and/or MR-39 on the GSDMD protein level. LPS only increased GSDMD production in the WT tissues, and this effect was ameliorated by MR-39. Collectively, this study indicates that the new FPR2 agonist efficiently abrogates LPS-induced neuroinflammation in an ex vivo model, as evidenced by a decrease in pro-inflammatory cytokine expression and release as well as the downregulation of NLRP3 inflammasome-related pathways.
Collapse
|
12
|
Ekuban FA, Zong C, Takikawa M, Morikawa K, Sakurai T, Ichihara S, Itoh K, Yamamoto M, Ohsako S, Ichihara G. Genetic ablation of Nrf2 exacerbates neurotoxic effects of acrylamide in mice. Toxicology 2021; 456:152785. [PMID: 33872730 DOI: 10.1016/j.tox.2021.152785] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/20/2021] [Accepted: 04/12/2021] [Indexed: 12/20/2022]
Abstract
Acrylamide (ACR), a recognized neurotoxicant in humans and experimental animals, is widely used in industry and in food generated through Maillard reaction. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of the cellular defense system and activates antioxidants and cytoprotective genes. The exact roles of Nrf2 in environmental electrophile-induced neurotoxicity is poorly understood. The aim of this study was to determine the roles of Nrf2 in ACR-induced neurotoxicity including degeneration of monoaminergic axons and sensorimotor dysfunction. Male 10-week-old C57BL/6JJcl Nrf2-knockout mice and wild type (WT) counterparts were each divided into four groups of 12 and provided with drinking water containing acrylamide at 0, 67, 110 or 200 ppm for four weeks. The effects of acrylamide were examined by landing foot spread test, immunohistochemistry for noradrenaline (NA) and serotonin (5-HT)-containing axons and Iba1-positive microglia in the prefrontal cortex as well as quantitative real-time polymerase chain reaction (qRT-PCR) on antioxidant, proinflammatory and anti-inflammatory genes in the prefrontal cortex. Relative to the wild type, exposure of Nrf2-knockout mice to acrylamide increased hindlimb splay length, microglial area and process length as well as decreasing the density of NA and 5-HT-immunoreactive axons to a greater extent. Moreover, deletion of Nrf2 gene suppressed acrylamide-induced mRNA upregulation of Nrf2-antioxidants, NAD(P): quinone oxidoreductase 1 (NQO1), superoxide dismutase-1 (SOD-1) and heme oxygenase-1 (HO-1) as well as anti-inflammatory markers such as, arginase-1 (Arg1), found in the inflammatory zone-1 (Fizz1), chitinase-like 3 (Chi3l3), interleukin-4 receptor alpha (IL-4Rα), cluster of differentiation 206 (CD206) and transforming growth factor beta-1 (TGFβ1) while enhancing acrylamide-induced upregulation of pro-inflammatory cytokines, interleukin-1 beta (IL-1β), tumor necrosis-alpha (TNF-α) and inducible nitric oxide synthase (iNOS) in the prefrontal cortex. The results demonstrate susceptibility of mice lacking the Nrf2 gene to acrylamide-induced neurotoxicity and neuroinflammation with the activation of microglia. Moreover, the results suggest the role of Nrf2 not only in induction of antioxidant gene expression, but also in suppression of proinflammatory cytokine gene expression.
Collapse
Affiliation(s)
- Frederick Adams Ekuban
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Cai Zong
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Madoka Takikawa
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Kota Morikawa
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Toshihiro Sakurai
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan
| | - Sahoko Ichihara
- Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan
| | - Ken Itoh
- Department of Stress Response Hirosaki University, Hirosaki, Japan
| | - Masayuki Yamamoto
- Department of Molecular Biochemistry Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Seiichiroh Ohsako
- Laboratory of Environmental Health Sciences, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Gaku Ichihara
- Department of Occupational and Environmental Health, Tokyo University of Science, Noda, Japan.
| |
Collapse
|
13
|
Exercise alters LPS-induced glial activation in the mouse brain. Neuronal Signal 2020; 4:NS20200003. [PMID: 33304620 PMCID: PMC7711064 DOI: 10.1042/ns20200003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 10/23/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022] Open
Abstract
Experimental and epidemiological evidence suggest that modifiable lifestyle factors, including physical exercise, can build structural and cognitive reserve in the brain, increasing resilience to injury and insult. Accordingly, exercise can reduce the increased expression of proinflammatory cytokines in the brain associated with ageing or experimentally induced neuroinflammation. However, the cellular mechanisms by which exercise exerts this effect are unknown, including the effects of exercise on classic or alternative activation of astrocytes and microglia. In the present study, we assess the effects of nine consecutive days of treadmill running on the glial cell response to a single systemic injection of lipopolysaccharide (LPS) and, in parallel, the effects on spatial learning and memory. We show that prior exercise protects against LPS-induced impairment of performance in the object displacement task concomitant with attenuation of IL-1β, TNFα and IL-10 mRNA expression in the hippocampus. Assessment of isolated astrocytes and microglia revealed that LPS induced a proinflammatory response in these cells that was not observed in cells prepared from the brains of mice who had undergone prior exercise. The results suggest that exercise modulates neuroinflammation by reducing the proinflammatory microglial response, suggesting a mechanism by which exercise may be neuroprotective.
Collapse
|
14
|
Quarta A, Berneman Z, Ponsaerts P. Neuroprotective modulation of microglia effector functions following priming with interleukin 4 and 13: current limitations in understanding their mode-of-action. Brain Behav Immun 2020; 88:856-866. [PMID: 32224056 DOI: 10.1016/j.bbi.2020.03.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 12/12/2022] Open
Abstract
In recent years the long-standing theory of microglia's properties for dual polarization towards a pro- or anti-inflammatory phenotype has been deeply challenged. Furthermore, the elucidation of microglia ontogenesis exposed intrinsic differences between microglia and peripheral myeloid cells, thereby further underscoring the need to re-evaluate microglia-specific activation behavior, especially within an inflamed central nervous system (CNS) environment. This review critically summarizes recent literature on the in vitro and in vivo response of murine microglia to the immune-modulatory cytokines interleukin 4 (IL4) and interleukin 13 (IL13), i.e. those driving the so-called anti-inflammatory phenotype. Here we highlight several pivotal factors that may influence experimental outcome and/or interpretation of in vitro and in vivo studies evaluating microglia's phenotypical and functional properties upon IL4/IL13 treatment. Finally, the current therapeutic relevance of IL4/IL13-induced microglia activation in both acute and chronic CNS disorders is discussed.
Collapse
Affiliation(s)
- Alessandra Quarta
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - Zwi Berneman
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - Peter Ponsaerts
- Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium.
| |
Collapse
|
15
|
Modulation of microglial phenotypes improves sepsis-induced hippocampus-dependent cognitive impairments and decreases brain inflammation in an animal model of sepsis. Clin Sci (Lond) 2020; 134:765-776. [PMID: 32219335 DOI: 10.1042/cs20191322] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/17/2020] [Accepted: 03/26/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND In order to modulate microglial phenotypes in vivo, M1 microglia were depleted by administration of gadolinium chloride and the expression of M2 microglia was induced by IL-4 administration in an animal model of sepsis to better characterize the role of microglial phenotypes in sepsis-induced brain dysfunction. METHODS Wistar rats were submitted to sham or cecal ligation and perforation (CLP) and treated with IL-4 or GdCl3. Animals were submitted to behavioral tests 10 days after surgery. In a separated cohort of animals at 24 h, 3 and 10 days after surgery, hippocampus was removed and cytokine levels, M1/M2 markers and CKIP-1 levels were determined. RESULTS Modulation of microglia by IL-4 and GdCl3 was associated with an improvement in long-term cognitive impairment. When treated with IL-4 and GdCl3, the reduction of pro-inflammatory cytokines was apparent in almost all analyzed time points. Additionally, CD11b and iNOS were increased after CLP at all time points, and both IL-4 and GdCl3 treatments were able to reverse this. There was a significant decrease in CD11b gene expression in the CLP+GdCl3 group. IL-4 treatment was able to decrease iNOS expression after sepsis. Furthermore, there was an increase of CKIP-1 in the hippocampus of GdCl3 and IL-4 treated animals 10 days after CLP induction. CONCLUSIONS GdCl3 and IL-4 are able to manipulate microglial phenotype in an animal models of sepsis, by increasing the polarization toward an M2 phenotype IL-4 and GdCl3 treatment was associated with decreased brain inflammation and functional recovery.
Collapse
|
16
|
Kolosowska N, Gotkiewicz M, Dhungana H, Giudice L, Giugno R, Box D, Huuskonen MT, Korhonen P, Scoyni F, Kanninen KM, Ylä-Herttuala S, Turunen TA, Turunen MP, Koistinaho J, Malm T. Intracerebral overexpression of miR-669c is protective in mouse ischemic stroke model by targeting MyD88 and inducing alternative microglial/macrophage activation. J Neuroinflammation 2020; 17:194. [PMID: 32560730 PMCID: PMC7304130 DOI: 10.1186/s12974-020-01870-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 06/08/2020] [Indexed: 12/30/2022] Open
Abstract
Background Ischemic stroke is a devastating disease without a cure. The available treatments for ischemic stroke, thrombolysis by tissue plasminogen activator, and thrombectomy are suitable only to a fraction of patients and thus novel therapeutic approaches are urgently needed. The neuroinflammatory responses elicited secondary to the ischemic attack further aggravate the stroke-induced neuronal damage. It has been demonstrated that these responses are regulated at the level of non-coding RNAs, especially miRNAs. Methods We utilized lentiviral vectors to overexpress miR-669c in BV2 microglial cells in order to modulate their polarization. To detect whether the modulation of microglial activation by miR-669c provides protection in a mouse model of transient focal ischemic stroke, miR-669c overexpression was driven by a lentiviral vector injected into the striatum prior to induction of ischemic stroke. Results Here, we demonstrate that miR-669c-3p, a member of chromosome 2 miRNA cluster (C2MC), is induced upon hypoxic and excitotoxic conditions in vitro and in two different in vivo models of stroke. Rather than directly regulating the neuronal survival in vitro, miR-669c is capable of attenuating the microglial proinflammatory activation in vitro and inducing the expression of microglial alternative activation markers arginase 1 (Arg1), chitinase-like 3 (Ym1), and peroxisome proliferator-activated receptor gamma (PPAR-γ). Intracerebral overexpression of miR-669c significantly decreased the ischemia-induced cell death and ameliorated the stroke-induced neurological deficits both at 1 and 3 days post injury (dpi). Albeit miR-669c overexpression failed to alter the overall Iba1 protein immunoreactivity, it significantly elevated Arg1 levels in the ischemic brain and increased colocalization of Arg1 and Iba1. Moreover, miR-669c overexpression under cerebral ischemia influenced several morphological characteristics of Iba1 positive cells. We further demonstrate the myeloid differentiation primary response gene 88 (MyD88) transcript as a direct target for miR-669c-3p in vitro and show reduced levels of MyD88 in miR-669c overexpressing ischemic brains in vivo. Conclusions Collectively, our data provide the evidence that miR-669c-3p is protective in a mouse model of ischemic stroke through enhancement of the alternative microglial/macrophage activation and inhibition of MyD88 signaling. Our results accentuate the importance of controlling miRNA-regulated responses for the therapeutic benefit in conditions of stroke and neuroinflammation.
Collapse
Affiliation(s)
- Natalia Kolosowska
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Maria Gotkiewicz
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Hiramani Dhungana
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Luca Giudice
- Department of Computer Science, University of Verona, Verona, Italy
| | - Rosalba Giugno
- Department of Computer Science, University of Verona, Verona, Italy
| | - Daphne Box
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Mikko T Huuskonen
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Paula Korhonen
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Flavia Scoyni
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Katja M Kanninen
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Seppo Ylä-Herttuala
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Tiia A Turunen
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Mikko P Turunen
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Jari Koistinaho
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland.,Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Tarja Malm
- University of Eastern Finland, A.I. Virtanen Institute for Molecular Sciences, P.O. Box 1627, FI-70211, Kuopio, Finland.
| |
Collapse
|
17
|
Villa A, Gelosa P, Castiglioni L, Cimino M, Rizzi N, Pepe G, Lolli F, Marcello E, Sironi L, Vegeto E, Maggi A. Sex-Specific Features of Microglia from Adult Mice. Cell Rep 2019; 23:3501-3511. [PMID: 29924994 PMCID: PMC6024879 DOI: 10.1016/j.celrep.2018.05.048] [Citation(s) in RCA: 372] [Impact Index Per Article: 74.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 04/06/2018] [Accepted: 05/14/2018] [Indexed: 12/25/2022] Open
Abstract
Sex has a role in the incidence and outcome of neurological illnesses, also influencing the response to treatments. Neuroinflammation is involved in the onset and progression of several neurological diseases, and the fact that estrogens have anti-inflammatory activity suggests that these hormones may be a determinant in the sex-dependent manifestation of brain pathologies. We describe significant differences in the transcriptome of adult male and female microglia, possibly originating from perinatal exposure to sex steroids. Microglia isolated from adult brains maintain the sex-specific features when put in culture or transplanted in the brain of the opposite sex. Female microglia are neuroprotective because they restrict the damage caused by acute focal cerebral ischemia. This study therefore provides insight into a distinct perspective on the mechanisms underscoring a sexual bias in the susceptibility to brain diseases. Transcriptome sequencing indicates sexual differentiation in adult murine microglia Female microglia show a neuroprotective phenotype, independent from hormonal cues Female microglia phenotype is retained after transfer into male brains The presence of female microglia protects male brains from ischemic stroke
Collapse
Affiliation(s)
- Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Paolo Gelosa
- Centro Cardiologico Monzino IRCCS, Milan 20138, Italy
| | - Laura Castiglioni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Mauro Cimino
- Department of Biomolecular Sciences, University of Urbino, Urbino 61029, Italy
| | - Nicoletta Rizzi
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Giovanna Pepe
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Federica Lolli
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Luigi Sironi
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy; Centro Cardiologico Monzino IRCCS, Milan 20138, Italy
| | - Elisabetta Vegeto
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases of the University of Milan, Milan 20133, Italy; Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy.
| |
Collapse
|
18
|
Montoya A, Elgueta D, Campos J, Chovar O, Falcón P, Matus S, Alfaro I, Bono MR, Pacheco R. Dopamine receptor D3 signalling in astrocytes promotes neuroinflammation. J Neuroinflammation 2019; 16:258. [PMID: 31810491 PMCID: PMC6896356 DOI: 10.1186/s12974-019-1652-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/19/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Neuroinflammation constitutes a pathogenic process leading to neurodegeneration in several disorders, including Alzheimer's disease, Parkinson's disease (PD) and sepsis. Despite microglial cells being the central players in neuroinflammation, astrocytes play a key regulatory role in this process. Our previous results indicated that pharmacologic-antagonism or genetic deficiency of dopamine receptor D3 (DRD3) attenuated neuroinflammation and neurodegeneration in two mouse models of PD. Here, we studied how DRD3-signalling affects the dynamic of activation of microglia and astrocyte in the context of systemic inflammation. METHODS Neuroinflammation was induced by intraperitoneal administration of LPS. The effect of genetic DRD3-deficiency or pharmacologic DRD3-antagonism in the functional phenotype of astrocytes and microglia was determined by immunohistochemistry and flow cytometry at different time-points. RESULTS Our results show that DRD3 was expressed in astrocytes, but not in microglial cells. DRD3 deficiency resulted in unresponsiveness of astrocytes and in attenuated microglial activation upon systemic inflammation. Furthermore, similar alterations in the functional phenotypes of glial cells were observed by DRD3 antagonism and genetic deficiency of DRD3 upon LPS challenge. Mechanistic analyses show that DRD3 deficiency resulted in exacerbated expression of the anti-inflammatory protein Fizz1 in glial cells both in vitro and in vivo. CONCLUSIONS These results suggest that DRD3 signalling regulates the dynamic of the acquisition of pro-inflammatory and anti-inflammatory features by astrocytes and microglia, finally favouring microglial activation and promoting neuroinflammation.
Collapse
Affiliation(s)
- Andro Montoya
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile
| | - Daniela Elgueta
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile
| | - Javier Campos
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile
| | - Ornella Chovar
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile
| | - Paulina Falcón
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile.,Facultad de Medicina y Ciencia, Universidad San Sebastián, Providencia, 7510157, Santiago, Chile
| | - Soledad Matus
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile.,Facultad de Medicina y Ciencia, Universidad San Sebastián, Providencia, 7510157, Santiago, Chile.,Center for Geroscience, Brain Health and Metabolism, 7800003, Santiago, Chile
| | - Iván Alfaro
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile.,Instituto de Ciencias e Innovación en Medicina, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Las Condes, 7590943, Santiago, Chile
| | - María Rosa Bono
- Departamento de Biología, Facultad de Ciencias, Universidad de Chile, 7800003, Santiago, Chile
| | - Rodrigo Pacheco
- Fundación Ciencia & Vida, Avenida Zañartu #1482, Ñuñoa, 7780272, Santiago, Chile. .,Facultad de Medicina y Ciencia, Universidad San Sebastián, Providencia, 7510157, Santiago, Chile. .,Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, 8370146, Santiago, Chile.
| |
Collapse
|
19
|
Dual Functions of Microglia in Ischemic Stroke. Neurosci Bull 2019; 35:921-933. [PMID: 31062335 DOI: 10.1007/s12264-019-00388-3] [Citation(s) in RCA: 296] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/30/2018] [Indexed: 12/16/2022] Open
Abstract
Ischemic stroke is a leading cause of morbidity and mortality worldwide. Resident microglia are the principal immune cells of the brain, and the first to respond to the pathophysiological changes induced by ischemic stroke. Traditionally, it has been thought that microglial activation is deleterious in ischemic stroke, and therapies to suppress it have been intensively explored. However, increasing evidence suggests that microglial activation is also critical for neurogenesis, angiogenesis, and synaptic remodeling, thereby promoting functional recovery after cerebral ischemia. Here, we comprehensively review the dual role of microglia during the different phases of ischemic stroke, and the possible mechanisms controlling the post-ischemic activity of microglia. In addition, we discuss the dynamic interactions between microglia and other cells, such as neurons, astrocytes, oligodendrocytes, and endothelial cells within the brain parenchyma and the neurovascular unit.
Collapse
|
20
|
Beckers L, Geric I, Stroobants S, Beel S, Van Damme P, D'Hooge R, Baes M. Microglia lacking a peroxisomal β-oxidation enzyme chronically alter their inflammatory profile without evoking neuronal and behavioral deficits. J Neuroinflammation 2019; 16:61. [PMID: 30866963 PMCID: PMC6417251 DOI: 10.1186/s12974-019-1442-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/24/2019] [Indexed: 11/10/2022] Open
Abstract
Background Microglia play a central role in most neurological disorders, but the impact of microgliosis on brain environment and clinical functions is not fully understood. Mice lacking multifunctional protein-2 (MFP2), a pivotal enzyme in peroxisomal β-oxidation, develop a fatal disorder characterized by motor problems similar to the milder form of MFP2 deficiency in humans. The hallmark of disease in mice is the chronic proliferation of microglia in the brain, but molecular pathomechanisms that drive rapid clinical deterioration in human and mice remain unknown. In the present study, we identified the effects of specific deletion of MFP2 from microglia in the brain on immune responses, neuronal functioning, and behavior. Methods We created a novel Cx3cr1-Mfp2−/− mouse model and studied the impact of MFP2 deficiency on microglial behavior at different ages using immunohistochemistry and real-time PCR. Pro- and anti-inflammatory responses of Mfp2−/− microglia were assessed in vitro and in vivo after stimulation with IL-1β/INFγ and IL-4 (in vitro) and LPS and IL-4 (in vivo). Facial nerve axotomy was unilaterally performed in Cx3cr1-Mfp2−/− and control mice, and microglial functioning in response to neuronal injury was subsequently analyzed by histology and real-time PCR. Finally, neuronal function, motor function, behavior, and cognition were assessed using brainstem auditory evoked potentials, grip strength and inverted grid test, open field exploration, and passive avoidance learning, respectively. Results We found that Mfp2−/− microglia in a genetically intact brain environment adopt an inflammatory activated and proliferative state. In addition, we found that acute inflammatory and neuronal injury provoked normal responses of Mfp2−/− microglia in Cx3cr1-Mfp2−/− mice during the post-injury period. Despite chronic pro-inflammatory microglial reactivity, Cx3cr1-Mfp2−/− mice exhibited normal neuronal transmission, clinical performance, and cognition. Conclusion Our data demonstrate that MFP2 deficiency in microglia causes intrinsic dysregulation of their inflammatory profile, which is not harmful to neuronal function, motor function, and cognition in mice during their first year of life. Electronic supplementary material The online version of this article (10.1186/s12974-019-1442-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lien Beckers
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, B-3000, Leuven, Belgium.,Present Address: Center for Translational and Computational Neuro-immunology, Department of Neurology, Columbia University Medical Center, New York City, NY, USA
| | - Ivana Geric
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, B-3000, Leuven, Belgium
| | - Stijn Stroobants
- Faculty of Psychology and Educational Sciences, Biological Psychology Unit, KU Leuven - University of Leuven, B-3000, Leuven, Belgium
| | - Sander Beel
- Department of Neurosciences, Laboratory for Neurobiology, KU Leuven - University of Leuven, Leuven, Belgium.,Center for Brain and Disease Research, VIB, Leuven, Belgium
| | - Philip Van Damme
- Department of Neurosciences, Laboratory for Neurobiology, KU Leuven - University of Leuven, Leuven, Belgium.,Center for Brain and Disease Research, VIB, Leuven, Belgium.,Neurology Department, University Hospitals Leuven, Leuven, Belgium
| | - Rudi D'Hooge
- Faculty of Psychology and Educational Sciences, Biological Psychology Unit, KU Leuven - University of Leuven, B-3000, Leuven, Belgium
| | - Myriam Baes
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, B-3000, Leuven, Belgium.
| |
Collapse
|
21
|
Ha JW, You MJ, Park HS, Kim JW, Kwon MS. Differential effect of LPS and paclitaxel on microglial functional phenotypes and circulating cytokines: the possible role of CX3CR1 and IL-4/10 in blocking persistent inflammation. Arch Pharm Res 2019; 42:359-368. [PMID: 30852731 DOI: 10.1007/s12272-019-01137-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 02/23/2019] [Indexed: 10/27/2022]
Abstract
Neuroinflammation plays a role in cancer chemotherapy-induced chronic pain. Thus far, most studies have focused on neuroinflammation suppression. However, there are limited reports of which factor is involved in the transition from acute inflammation to chronic inflammation, resulting in neuroinflammation and chronic pain. Here, we compared the inflammatory reaction and pain response induced by LPS and paclitaxel. LPS (0.5 mg/kg) or paclitaxel (2 mg/kg/day for 5 days) was administered intraperitoneally to mice, and mechanical allodynia was examined by von Frey test. LPS induced transient mechanical allodynia, whereas paclitaxel induced persistent mechanical allodynia. The CD86/CX3CR1 ratio remained unchanged due to CX3CR1 elevation following LPS injection, whereas the ratio was increased on day 1 after paclitaxel injection. LPS also increased CD45, CCL2, and CCL5 mRNA in the spinal cord and circulating pro- and anti-inflammatory cytokines 1 day after injection; however, the pattern was not consistent. Paclitaxel gradually increased inflammatory cytokines in the spinal cord. CX3CR1 might be involved in blocking the transition from acute pain to persistent pain in the LPS group. In addition, serum IL-4 and IL-10 elevation in the LPS group may be associated with chronic pain prevention. Therefore, targeting CX3CR1, IL-4, and IL-10 might be an alternative therapeutic strategy.
Collapse
Affiliation(s)
- Joong-Won Ha
- Department of Pharmacology, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea.,Department of Orthopedic Surgery, National Health Insurance Service Ilsan Hospital, Ilsan, 10444, Republic of Korea
| | - Min-Jung You
- Department of Pharmacology, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea
| | - Hyun-Sun Park
- Department of Pharmacology, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea
| | - Jong Wan Kim
- Department of Surgery, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, 40 Sukwoo-Dong, Hwaseong-Si, Gyeonggi-do, 14068, Republic of Korea.
| | - Min-Soo Kwon
- Department of Pharmacology, School of Medicine, CHA University, CHA Bio Complex, 335 Pangyo, Bundang-gu, Seongnam-si, Gyeonggi-do, 13488, Republic of Korea.
| |
Collapse
|
22
|
Starossom SC, Campo Garcia J, Woelfle T, Romero-Suarez S, Olah M, Watanabe F, Cao L, Yeste A, Tukker JJ, Quintana FJ, Imitola J, Witzel F, Schmitz D, Morkel M, Paul F, Infante-Duarte C, Khoury SJ. Chi3l3 induces oligodendrogenesis in an experimental model of autoimmune neuroinflammation. Nat Commun 2019; 10:217. [PMID: 30644388 PMCID: PMC6333780 DOI: 10.1038/s41467-018-08140-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/18/2018] [Indexed: 01/19/2023] Open
Abstract
In demyelinating diseases including multiple sclerosis (MS), neural stem cells (NSCs) can replace damaged oligodendrocytes if the local microenvironment supports the required differentiation process. Although chitinase-like proteins (CLPs) form part of this microenvironment, their function in this differentiation process is unknown. Here, we demonstrate that murine Chitinase 3-like-3 (Chi3l3/Ym1), human Chi3L1 and Chit1 induce oligodendrogenesis. In mice, Chi3l3 is highly expressed in the subventricular zone, a stem cell niche of the adult brain, and in inflammatory brain lesions during experimental autoimmune encephalomyelitis (EAE). We find that silencing Chi3l3 increases severity of EAE. We present evidence that in NSCs Chi3l3 activates the epidermal growth factor receptor (EGFR), thereby inducing Pyk2-and Erk1/2- dependent expression of a pro-oligodendrogenic transcription factor signature. Our results implicate CLP-EGFR-Pyk2-MEK-ERK as a key intrinsic pathway controlling oligodendrogenesis.
Collapse
Affiliation(s)
- Sarah C Starossom
- Institute for Medical Immunology, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany.
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, Berlin, Germany.
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany.
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
| | - Juliana Campo Garcia
- Institute for Medical Immunology, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Tim Woelfle
- Institute for Medical Immunology, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Silvina Romero-Suarez
- Institute for Medical Immunology, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Marta Olah
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Fumihiro Watanabe
- Laboratory of Neural Stem Cells and Functional Neurogenetics, Department of Neurology-The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Li Cao
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Ada Yeste
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - John J Tukker
- Neuroscience Research Center (NWFZ), Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
- DZNE-German Center for Neurodegenerative Diseases, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Francisco J Quintana
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jaime Imitola
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Laboratory of Neural Stem Cells and Functional Neurogenetics, Department of Neurology-The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Franziska Witzel
- IRI Life Sciences, Institute of Pathology, Computational Modeling in Medicine, Charité- Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Dietmar Schmitz
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
- Neuroscience Research Center (NWFZ), Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
- IRI Life Sciences, Institute of Pathology, Computational Modeling in Medicine, Charité- Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Markus Morkel
- Institute of Pathology, Laboratory of Molecular Tumor Pathology and Systems Biology, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Friedemann Paul
- Experimental and Clinical Research Center, Max Delbrueck Center for Molecular Medicine and Charité - Universitätsmedizin Berlin, Berlin, Germany
- NeuroCure Clinical Research Center, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
- Department of Neurology, Charité - Universitätsmedizin Berlin, 10117, Berlin, Germany
| | - Carmen Infante-Duarte
- Institute for Medical Immunology, Charité - Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Samia J Khoury
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Abu Haidar Neuroscience Institute, American University of Beirut Medical Center, Beirut, Lebanon
| |
Collapse
|
23
|
Cengiz P, Zafer D, Chandrashekhar JH, Chanana V, Bogost J, Waldman A, Novak B, Kintner DB, Ferrazzano PA. Developmental differences in microglia morphology and gene expression during normal brain development and in response to hypoxia-ischemia. Neurochem Int 2019; 127:137-147. [PMID: 30639264 DOI: 10.1016/j.neuint.2018.12.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/27/2018] [Accepted: 12/27/2018] [Indexed: 12/16/2022]
Abstract
BACKGROUND Neuroinflammation plays an important role in ischemic brain injury and recovery, however the interplay between brain development and the neuroinflammatory response is poorly understood. We previously described age-dependent differences in the microglial response and the effect of microglial inhibition. Here we investigate whether age-dependent microglial responses may be related to pre-injury developmental differences in microglial phenotype. METHODS Measures of microglia morphology were quantified using semi-automated software analysis of immunostained sections from postnatal day 2 (P2), P9, P30 and P60 mice using IMARIS. Microglia were isolated from P2, P9, P30 and P60 mice, and expression of markers of classical and alternative microglial activation was assessed, as well as transforming growth factor beta (TGF-β) receptor, Serpine1, Mer Tyrosine Kinase (MerTK), and the suppressor of cytokine signaling (SOCS3). Hypoxia-ischemia (HI) was induced in P9 and P30 mice using unilateral carotid artery ligation and exposure to 10% oxygen for 50 min. Microglia morphology and microglial expression of genes in the TGF-β and MerTK pathways were determined in ipsilateral and contralateral hippocampus. RESULTS A progressive and significant increase in microglia branching morphology was seen in all brain regions from P2 to P30. No consistent classical or alternative activation profile was seen in isolated microglia. A clear transition to increased expression of TGF-β and its downstream effector serpine1 was seen between P9 and P30. A similar increase in expression was seen in MerTK and its downstream effector SOCS3. HI resulted in a significant decrease in branching morphology only in the P9 mice, and expression of TGF-β receptor, Serpine1, MerTK, and SOCS3 were elevated in P30 mice compared to P9 post-HI. CONCLUSION Microglia maturation is associated with changes in morphology and gene expression, and microglial responses to ischemia in the developing brain differ based on the age at which injury occurs.
Collapse
Affiliation(s)
- Pelin Cengiz
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Dila Zafer
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jayadevi H Chandrashekhar
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; University of Illinois at Urbana-Champaign, IL, USA
| | - Vishal Chanana
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jacob Bogost
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Alex Waldman
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Emory University School of Medicine, Atlanta, GA, USA
| | - Becca Novak
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Douglas B Kintner
- Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Peter A Ferrazzano
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Waisman Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| |
Collapse
|
24
|
Villa A, Della Torre S, Maggi A. Sexual differentiation of microglia. Front Neuroendocrinol 2019; 52:156-164. [PMID: 30481522 DOI: 10.1016/j.yfrne.2018.11.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/07/2018] [Accepted: 11/24/2018] [Indexed: 12/28/2022]
Abstract
Sex plays a role in the incidence and outcome of neurological illnesses, also influencing the response to treatments. Despite sexual differentiation of the brain has been extensively investigated, the study of sex differences in microglia, the brain's resident immune cells, has been largely neglected until recently. To fulfill this gap, our laboratory developed several tools, including cellular and animal models, which bolstered in-depth studies on sexual differentiation of microglia and its impact on brain physiology, as well as on the onset and progression of neurological disorders. Here, we summarize the current status of knowledge on the sex-dependent function of microglia, and report recent evidence linking these cells to the sexual bias in the susceptibility to neurological brain diseases.
Collapse
Affiliation(s)
- Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases and Dept of Pharmacological and Biomolecular Sciences, University of Milan, via Balzaretti, 9, Milan, Italy
| | - Sara Della Torre
- Center of Excellence on Neurodegenerative Diseases and Dept of Pharmacological and Biomolecular Sciences, University of Milan, via Balzaretti, 9, Milan, Italy
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases and Dept of Pharmacological and Biomolecular Sciences, University of Milan, via Balzaretti, 9, Milan, Italy.
| |
Collapse
|
25
|
Beckers L, Ory D, Geric I, Declercq L, Koole M, Kassiou M, Bormans G, Baes M. Increased Expression of Translocator Protein (TSPO) Marks Pro-inflammatory Microglia but Does Not Predict Neurodegeneration. Mol Imaging Biol 2018; 20:94-102. [PMID: 28695372 DOI: 10.1007/s11307-017-1099-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE Activation of the innate immune system plays a significant role in pathologies of the central nervous system (CNS). In order to follow disease progression and evaluate effectiveness of potential treatments involved in neuroinflammation, it is important to track neuroinflammatory markers in vivo longitudinally. The translocator protein (TSPO) is used as a target to image neuroinflammation as its expression is upregulated in reactive glial cells during CNS pathologies. However, it remains unclear in which microglial phenotypes TSPO levels are upregulated, as microglia can display a plethora of activation states that can be protective or detrimental to the CNS. PROCEDURES We assessed the levels of TSPO transcripts in cultured microglia that were polarized into pro- and anti-inflammatory states in vitro and in the brain of mice in which an anti-inflammatory environment was induced in vivo. In addition, we used a mouse model of peroxisomal multifunctional protein-2 (MFP2) deficiency that exhibits widespread neuroinflammation despite no neuronal loss and monitored TSPO expression by immunohistochemistry and by imaging using the TSPO radiotracer [18F]DPA-714. RESULTS TSPO expression was selectively increased in so-called classically activated or M1 microglia but not in alternatively activated or M2 microglia in vitro. In agreement, TSPO transcript levels were not induced in an anti-inflammatory brain environment. We found that both transcript and protein levels of TSPO are significantly increased in the brain of Mfp2 -/- compared to those of the control mice and TSPO immunoreactivity colocalized predominantly with microglia in Mfp2 -/- brain. In vitro and ex vivo autoradiography in Mfp2 -/- mice using the TSPO radiotracer [18F]DPA-714 confirmed increased expression of TSPO. These data demonstrate that TSPO imaging reveals microgliosis in non-neurodegenerative brain pathologies. CONCLUSIONS We show that induced TSPO expression marks a pro-inflammatory brain environment that is not necessarily accompanied by neuronal loss.
Collapse
Affiliation(s)
- Lien Beckers
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, 3000, Leuven, Belgium
| | - Dieter Ory
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Radiopharmacy, KU Leuven - University of Leuven, Leuven, Belgium
| | - Ivana Geric
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, 3000, Leuven, Belgium
| | - Lieven Declercq
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Radiopharmacy, KU Leuven - University of Leuven, Leuven, Belgium
| | - Michel Koole
- Department of Nuclear Medicine and Molecular Imaging, KU Leuven- University of Leuven, Leuven, Belgium
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Guy Bormans
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Radiopharmacy, KU Leuven - University of Leuven, Leuven, Belgium
| | - Myriam Baes
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Cell Metabolism, KU Leuven - University of Leuven, Campus Gasthuisberg O/N2, Herestraat 49, 3000, Leuven, Belgium.
| |
Collapse
|
26
|
Villa A, Klein B, Janssen B, Pedragosa J, Pepe G, Zinnhardt B, Vugts DJ, Gelosa P, Sironi L, Beaino W, Damont A, Dollé F, Jego B, Winkeler A, Ory D, Solin O, Vercouillie J, Funke U, Laner-Plamberger S, Blomster LV, Christophersen P, Vegeto E, Aigner L, Jacobs A, Planas AM, Maggi A, Windhorst AD. Identification of new molecular targets for PET imaging of the microglial anti-inflammatory activation state. Am J Cancer Res 2018; 8:5400-5418. [PMID: 30555554 PMCID: PMC6276082 DOI: 10.7150/thno.25572] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 08/27/2018] [Indexed: 12/20/2022] Open
Abstract
Microglia are potential targets for therapeutic intervention in neurological and neurodegenerative diseases affecting the central nervous system. In order to assess the efficacy of therapies aimed to reduce the tissue damaging activities of microglia and/or to promote the protective potential of these cells, suitable pre-clinical and clinical tools for the in vivo analysis of microglia activities and dynamics are required. The aim of this work was to identify new translational markers of the anti-inflammatory / protective state of microglia for the development of novel PET tracers. Methods: New translational markers of the anti-inflammatory/protective activation state of microglia were selected by bioinformatic approaches and were in vitro and ex vivo validated by qPCR and immunohistochemistry in rodent and human samples. Once a viable marker was identified, a novel PET tracer was developed. This tracer was subsequently confirmed by autoradiography experiments in murine and human brain tissues. Results: Here we provide evidence that P2RY12 expression increases in murine and human microglia following exposure to anti-inflammatory stimuli, and that its expression is modulated in the reparative phase of experimental and clinical stroke. We then synthesized a novel carbon-11 labeled tracer targeting P2RY12, showing increased binding in brain sections of mice treated with IL4, and low binding to brain sections of a murine stroke model and of a stroke patient. Conclusion: This study provides new translational targets for PET tracers for the anti-inflammatory/protective activation state of microglia and shows the potential of a rationale-based approach. It therefore paves the way for the development of novel non-invasive methodologies aimed to monitor the success of therapeutic approaches in various neurological diseases.
Collapse
|
27
|
Fumagalli M, Lombardi M, Gressens P, Verderio C. How to reprogram microglia toward beneficial functions. Glia 2018; 66:2531-2549. [PMID: 30195261 PMCID: PMC6585737 DOI: 10.1002/glia.23484] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/13/2018] [Accepted: 06/13/2018] [Indexed: 12/13/2022]
Abstract
Microglia, brain cells of nonneural origin, orchestrate the inflammatory response to diverse insults, including hypoxia/ischemia or maternal/fetal infection in the perinatal brain. Experimental studies have demonstrated the capacity of microglia to recognize pathogens or damaged cells activating a cytotoxic response that can exacerbate brain damage. However, microglia display an enormous plasticity in their responses to injury and may also promote resolution stages of inflammation and tissue regeneration. Despite the critical role of microglia in brain pathologies, the cellular mechanisms that govern the diverse phenotypes of microglia are just beginning to be defined. Here we review emerging strategies to drive microglia toward beneficial functions, selectively reporting the studies which provide insights into molecular mechanisms underlying the phenotypic switch. A variety of approaches have been proposed which rely on microglia treatment with pharmacological agents, cytokines, lipid messengers, or microRNAs, as well on nutritional approaches or therapies with immunomodulatory cells. Analysis of the molecular mechanisms relevant for microglia reprogramming toward pro‐regenerative functions points to a central role of energy metabolism in shaping microglial functions. Manipulation of metabolic pathways may thus provide new therapeutic opportunities to prevent the deleterious effects of inflammatory microglia and to control excessive inflammation in brain disorders.
Collapse
Affiliation(s)
- Marta Fumagalli
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti, 9 -20133, Milan, Italy
| | | | - Pierre Gressens
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, 1141 Paris, France.,Centre for the Developing Brain, Department of Perinatal Health and Imaging, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, SE1 7EH, United Kingdom
| | - Claudia Verderio
- IRCCS Humanitas, via Manzoni 56, 20089, Rozzano, Italy.,CNR Institute of Neuroscience, via Vanvitelli 32, 20129 Milan, Italy
| |
Collapse
|
28
|
Salminen A, Kaarniranta K, Kauppinen A. The potential importance of myeloid-derived suppressor cells (MDSCs) in the pathogenesis of Alzheimer's disease. Cell Mol Life Sci 2018; 75:3099-3120. [PMID: 29779041 PMCID: PMC11105369 DOI: 10.1007/s00018-018-2844-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/30/2018] [Accepted: 05/16/2018] [Indexed: 02/08/2023]
Abstract
The exact cause of Alzheimer's disease (AD) is still unknown, but the deposition of amyloid-β (Aβ) plaques and chronic inflammation indicates that immune disturbances are involved in AD pathogenesis. Recent genetic studies have revealed that many candidate genes are expressed in both microglia and myeloid cells which infiltrate into the AD brains. Invading myeloid cells controls the functions of resident microglia in pathological conditions, such as AD pathology. AD is a neurologic disease with inflammatory component where the immune system is not able to eliminate the perpetrator, while, concurrently, it should prevent neuronal injuries induced by inflammation. Recent studies have indicated that AD brains are an immunosuppressive microenvironment, e.g., microglial cells are hyporesponsive to Aβ deposits and anti-inflammatory cytokines enhance Aβ deposition. Immunosuppression is a common element in pathological disorders involving chronic inflammation. Studies on cancer-associated inflammation have demonstrated that myeloid-derived suppressor cells (MDSCs) have a crucial role in the immune escape of tumor cells. Immunosuppression is not limited to tumors, since MDSCs can be recruited into chronically inflamed tissues where inflammatory mediators enhance the proliferation and activation of MDSCs. AD brains express a range of chemokines and cytokines which could recruit and expand MDSCs in inflamed AD brains and thus generate an immunosuppressive microenvironment. Several neuroinflammatory disorders, e.g., the early phase of AD pathology, have been associated with an increase in the level of circulating MDSCs. We will elucidate the immunosuppressive armament of MDSCs and present evidences in support of the crucial role of MDSCs in the pathogenesis of AD.
Collapse
Affiliation(s)
- Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, 70029 KYS, Kuopio, Finland
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland
| |
Collapse
|
29
|
Gładysz D, Krzywdzińska A, Hozyasz KK. Immune Abnormalities in Autism Spectrum Disorder-Could They Hold Promise for Causative Treatment? Mol Neurobiol 2018; 55:6387-6435. [PMID: 29307081 PMCID: PMC6061181 DOI: 10.1007/s12035-017-0822-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/05/2017] [Indexed: 12/15/2022]
Abstract
Autism spectrum disorders (ASD) are characterized by impairments in language and communication development, social behavior, and the occurrence of stereotypic patterns of behavior and interests. Despite substantial speculation about causes of ASD, its exact etiology remains unknown. Recent studies highlight a link between immune dysfunction and behavioral traits. Various immune anomalies, including humoral and cellular immunity along with abnormalities at the molecular level, have been reported. There is evidence of altered immune function both in cerebrospinal fluid and peripheral blood. Several studies hypothesize a role for neuroinflammation in ASD and are supported by brain tissue and cerebrospinal fluid analysis, as well as evidence of microglial activation. It has been shown that immune abnormalities occur in a substantial number of individuals with ASD. Identifying subgroups with immune system dysregulation and linking specific cellular immunophenotypes to different symptoms would be key to defining a group of patients with immune abnormalities as a major etiology underlying behavioral symptoms. These determinations would provide the opportunity to investigate causative treatments for a defined patient group that may specifically benefit from such an approach. This review summarizes recent insights into immune system dysfunction in individuals with ASD and discusses the potential implications for future therapies.
Collapse
Affiliation(s)
- Dominika Gładysz
- Department of Pediatrics, Institute of Mother and Child, Warsaw, Poland
| | | | - Kamil K Hozyasz
- Department of Pediatrics, Institute of Mother and Child, Warsaw, Poland.
| |
Collapse
|
30
|
Casella G, Colombo F, Finardi A, Descamps H, Ill-Raga G, Spinelli A, Podini P, Bastoni M, Martino G, Muzio L, Furlan R. Extracellular Vesicles Containing IL-4 Modulate Neuroinflammation in a Mouse Model of Multiple Sclerosis. Mol Ther 2018; 26:2107-2118. [PMID: 30017878 DOI: 10.1016/j.ymthe.2018.06.024] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/22/2018] [Accepted: 06/25/2018] [Indexed: 12/31/2022] Open
Abstract
Extracellular vesicles (EVs) play a major role in cell-to-cell communication in physiological and pathological conditions, and their manipulation may represent a promising therapeutic strategy. Microglia, the parenchymal mononuclear phagocytes of the brain, modulate neighboring cells also through the release of EVs. The production of custom EVs filled with desired molecules, possibly targeted to make their uptake cell specific, and their administration in biological fluids may represent a valid approach for drug delivery. We engineered a murine microglia cell line, BV-2, to release EVs overexpressing the endogenous "eat me" signal Lactadherin (Mfg-e8) on the surface to target phagocytes and containing the anti-inflammatory cytokine IL-4. A single injection of 107 IL-4+Mfg-e8+ EVs into the cisterna magna modulated established neuroinflammation and significantly reduced clinical signs in the mouse model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). Injected IL-4+Mfg-e8+ EVs target mainly phagocytes (i.e., macrophages and microglia) surrounding liquoral spaces, and their cargo promote the upregulation of anti-inflammatory markers chitinase 3-like 3 (ym1) and arginase-1 (arg1), significantly reducing tissue damage. Engineered EVs may represent a biological drug delivery tool able to deliver multiple functional molecules simultaneously to treat neuroinflammatory diseases.
Collapse
Affiliation(s)
- Giacomo Casella
- Clinical Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology (InSpe), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Federico Colombo
- Clinical Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology (InSpe), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Annamaria Finardi
- Clinical Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology (InSpe), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Hélène Descamps
- Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Gerard Ill-Raga
- Clinical Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology (InSpe), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Antonello Spinelli
- Experimental Imaging Centre, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Paola Podini
- Department of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Mattia Bastoni
- Clinical Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology (InSpe), San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Gianvito Martino
- Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Luca Muzio
- Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Roberto Furlan
- Clinical Neuroimmunology Unit, Department of Neuroscience, Institute of Experimental Neurology (InSpe), San Raffaele Scientific Institute, 20132 Milan, Italy.
| |
Collapse
|
31
|
Sandvig I, Augestad IL, Håberg AK, Sandvig A. Neuroplasticity in stroke recovery. The role of microglia in engaging and modifying synapses and networks. Eur J Neurosci 2018; 47:1414-1428. [PMID: 29786167 DOI: 10.1111/ejn.13959] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 02/06/2023]
Abstract
Neuroplasticity after ischaemic injury involves both spontaneous rewiring of neural networks and circuits as well as functional responses in neurogenic niches. These events involve complex interactions with activated microglia, which evolve in a dynamic manner over time. Although the exact mechanisms underlying these interactions remain poorly understood, increasing experimental evidence suggests a determining role of pro- and anti-inflammatory microglial activation profiles in shaping both synaptogenesis and neurogenesis. While the inflammatory response of microglia was thought to be detrimental, a more complex profile of the role of microglia in tissue remodelling is emerging. Experimental evidence suggests that microglia in response to injury can rapidly modify neuronal activity and modulate synaptic function, as well as be beneficial for the proliferation and integration of neural progenitor cells (NPCs) from endogenous neurogenic niches into functional networks thereby supporting stroke recovery. The manner in which microglia contribute towards sculpting neural synapses and networks, both in terms of activity-dependent and homeostatic plasticity, suggests that microglia-mediated pro- and/or anti-inflammatory activity may significantly contribute towards spontaneous neuronal plasticity after ischaemic lesions. In this review, we first introduce some of the key cellular and molecular mechanisms underlying neuroplasticity in stroke and then proceed to discuss the crosstalk between microglia and endogenous neuroplasticity in response to brain ischaemia with special focus on the engagement of synapses and neural networks and their implications for grey matter integrity and function in stroke repair.
Collapse
Affiliation(s)
- Ioanna Sandvig
- Faculty of Medicine and Health Sciences, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Ingrid Lovise Augestad
- Faculty of Medicine and Health Sciences, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Asta Kristine Håberg
- Faculty of Medicine and Health Sciences, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.,Department of Radiology and Nuclear Medicine, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Axel Sandvig
- Faculty of Medicine and Health Sciences, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.,Department of Neurology, St Olav's Hospital, Trondheim University Hospital, Trondheim, Norway.,Department of Pharmacology and Clinical Neurosciences, Division of Neuro, Head and Neck, Umeå University Hospital, Umeå, Sweden
| |
Collapse
|
32
|
Xu H, Qin W, Hu X, Mu S, Zhu J, Lu W, Luo Y. Lentivirus-mediated overexpression of OTULIN ameliorates microglia activation and neuroinflammation by depressing the activation of the NF-κB signaling pathway in cerebral ischemia/reperfusion rats. J Neuroinflammation 2018; 15:83. [PMID: 29544517 PMCID: PMC5856386 DOI: 10.1186/s12974-018-1117-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 03/06/2018] [Indexed: 01/05/2023] Open
Abstract
Background Ischemic stroke-induced neuroinflammation is mainly mediated by microglial cells. The nuclear factor kappa B (NF-κB) pathway is the key transcriptional pathway that initiates inflammatory responses following cerebral ischemia. OTULIN, a critical negative regulator of the NF-κΒ signaling pathway, exerts robust effects on peripheral immune cell-mediated inflammation and is regarded as an essential mediator for repressing inflammation in vivo. The effect of OTULIN on inflammatory responses in the central nervous system (CNS) was previously unstudied. This current study investigated the anti-inflammatory effect of OTULIN both in vitro and in vivo in ischemic stroke models. Methods Sprague-Dawley (SD) rats were subjected to transient middle cerebral artery occlusion (tMCAO) or an intraperitoneal injection of lipopolysaccharide (LPS). Overexpression of the OTULIN gene was utilized to observe the effect of OTULIN on ischemic stroke outcomes. The effect of OTULIN overexpression on microglia-mediated neuroinflammation was examined in rat primary microglia (PM) and in the microglial cell line N9 after induction by oxygen-glucose deprivation (OGD)-treated neuronal medium. The activation and inflammatory responses of microglia were detected using immunofluorescence, ELISA, and qRT-PCR. The details of molecular mechanism were assessed using Western blotting. Results In the tMCAO rats, the focal cerebral ischemia/reperfusion injury induced a continuous increase in OTULIN expression within 72 h, and OTULIN expression was increased in activated microglial cells. OTULIN overexpression obviously decreased the cerebral infarct volume, improved the neurological function deficits, and reduced neuronal loss at 72 h after reperfusion, and it also inhibited the activation of microglia and attenuated the release of TNF-α, IL-1β, and IL-6 by suppressing the NF-κB pathway at 24 h after tMCAO. In vitro, OTULIN overexpression inhibited the microglia-mediated neuroinflammation by reducing the production of TNF-α, IL-1β, and IL-6 via depressing the NF-κB pathway in both PM and N9 cells. Conclusions OTULIN provides a potential therapeutic target for ischemic brain injury by ameliorating the excessive activation of microglial cells and neuroinflammation through repressing the NF-κB signaling pathway. Electronic supplementary material The online version of this article (10.1186/s12974-018-1117-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Hongbei Xu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.,Laboratory Research Center, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Wenyi Qin
- Department of Integrated Chinese and Western Medicine, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Xiao Hu
- Department of Neurology, Guizhou Provincial People's hospital, Guizhou, 50002, China
| | - Song Mu
- Department of Anus & Intestine surgery, the Affiliated Hospital of Guizhou Medical University, Guizhou, 550004, China
| | - Jun Zhu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.,Laboratory Research Center, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Wenhao Lu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.,Laboratory Research Center, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Yong Luo
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China. .,Laboratory Research Center, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
| |
Collapse
|
33
|
Interleukin 4 modulates microglia homeostasis and attenuates the early slowly progressive phase of amyotrophic lateral sclerosis. Cell Death Dis 2018; 9:250. [PMID: 29445154 PMCID: PMC5833860 DOI: 10.1038/s41419-018-0288-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/28/2017] [Accepted: 01/04/2018] [Indexed: 12/31/2022]
Abstract
Microglia activation is a commonly pathological hallmark of neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), a devastating disorder characterized by a selective motor neurons degeneration. Whether such activation might represent a causal event rather than a secondary epiphenomenon remains elusive. Here, we show that CNS-delivery of IL-4—via a lentiviral-mediated gene therapy strategy—skews microglia to proliferate, inducing these cells to adopt the phenotype of slowly proliferating cells. Transcriptome analysis revealed that IL-4-treated microglia express a broad number of genes normally encoded by embryonic microglia. Since embryonic microglia sustain CNS development, we then hypothesized that turning adult microglia to acquire such phenotype via IL-4 might be an efficient in vivo strategy to sustain motor neuron survival in ALS. IL-4 gene therapy in SOD1G93A mice resulted in a general amelioration of clinical outcomes during the early slowly progressive phase of the disease. However, such approach did not revert neurodegenerative processes occurring in the late and fast progressing phase of the disease.
Collapse
|
34
|
Stephenson CP, Baguley IJ. Functional neurological symptom disorder (conversion disorder): A role for microglial-based plasticity mechanisms? Med Hypotheses 2018; 111:41-48. [DOI: 10.1016/j.mehy.2017.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 11/12/2017] [Accepted: 12/03/2017] [Indexed: 10/18/2022]
|
35
|
Mecca C, Giambanco I, Donato R, Arcuri C. Microglia and Aging: The Role of the TREM2-DAP12 and CX3CL1-CX3CR1 Axes. Int J Mol Sci 2018; 19:E318. [PMID: 29361745 PMCID: PMC5796261 DOI: 10.3390/ijms19010318] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 12/21/2022] Open
Abstract
Depending on the species, microglial cells represent 5-20% of glial cells in the adult brain. As the innate immune effector of the brain, microglia are involved in several functions: regulation of inflammation, synaptic connectivity, programmed cell death, wiring and circuitry formation, phagocytosis of cell debris, and synaptic pruning and sculpting of postnatal neural circuits. Moreover, microglia contribute to some neurodevelopmental disorders such as Nasu-Hakola disease (NHD), and to aged-associated neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and others. There is evidence that human and rodent microglia may become senescent. This event determines alterations in the microglia activation status, associated with a chronic inflammation phenotype and with the loss of neuroprotective functions that lead to a greater susceptibility to the neurodegenerative diseases of aging. In the central nervous system (CNS), Triggering Receptor Expressed on Myeloid Cells 2-DNAX activation protein 12 (TREM2-DAP12) is a signaling complex expressed exclusively in microglia. As a microglial surface receptor, TREM2 interacts with DAP12 to initiate signal transduction pathways that promote microglial cell activation, phagocytosis, and microglial cell survival. Defective TREM2-DAP12 functions play a central role in the pathogenesis of several diseases. The CX3CL1 (fractalkine)-CX3CR1 signaling represents the most important communication channel between neurons and microglia. The expression of CX3CL1 in neurons and of its receptor CX3CR1 in microglia determines a specific interaction, playing fundamental roles in the regulation of the maturation and function of these cells. Here, we review the role of the TREM2-DAP12 and CX3CL1-CX3CR1 axes in aged microglia and the involvement of these pathways in physiological CNS aging and in age-associated neurodegenerative diseases.
Collapse
Affiliation(s)
- Carmen Mecca
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| | - Ileana Giambanco
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| | - Rosario Donato
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
- Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| | - Cataldo Arcuri
- Department of Experimental Medicine, Perugia Medical School, University of Perugia, Piazza Lucio Severi 1, 06132 Perugia, Italy.
| |
Collapse
|
36
|
Pepe G, De Maglie M, Minoli L, Villa A, Maggi A, Vegeto E. Selective proliferative response of microglia to alternative polarization signals. J Neuroinflammation 2017; 14:236. [PMID: 29202771 PMCID: PMC5715534 DOI: 10.1186/s12974-017-1011-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 11/22/2017] [Indexed: 01/29/2023] Open
Abstract
Background Microglia are resident myeloid cells of the central nervous system (CNS) that are maintained by self-renewal and actively participate in tissue homeostasis and immune defense. Under the influence of endogenous or pathological signals, microglia undertake biochemical transformations that are schematically classified as the pro-inflammatory M1 phenotype and the alternatively activated M2 state. Dysregulated proliferation of M1-activated microglia has detrimental effects, while an increased number of microglia with the alternative, pro-resolving phenotype might be beneficial in brain pathologies; however, the proliferative response of microglia to M2 signals is not yet known. We thus evaluated the ability of interleukin-4 (IL-4), a typical M2 and proliferative signal for peripheral macrophages, to induce microglia proliferation and compared it with other proliferative and M2 polarizing stimuli for macrophages, namely colony-stimulating factor-1 (CSF-1) and the estrogen hormone, 17β-estradiol (E2). Methods Recombinant IL-4 was delivered to the brain of adult mice by intracerebroventricular (i.c.v.) injection; whole brain areas or ex vivo-sorted microglia were analyzed by real-time PCR for assessing the mRNA levels of genes related with cell proliferation (Ki67, CDK-1, and CcnB2) and M2 polarization (Arg1, Fizz1, Ym-1) or by FACS analyses of in vivo BrdU incorporation in microglia. Primary cultures of microglia and astrocytes were also tested for proliferative effects. Results Our results show that IL-4 only slightly modified the expression of cell cycle-related genes in some brain areas but not in microglia, where it strongly enhanced M2 gene expression; on the contrary, brain delivery of CSF-1 triggered proliferation as well as M2 polarization of microglia both in vivo and in vitro. Similar to IL-4, the systemic E2 administration failed to induce microglia proliferation while it increased M2 gene expression. Conclusions Our data show that, in contrast to the wider responsiveness of peripheral macrophages, microglia proliferation is stimulated by selected M2 polarizing stimuli suggesting a role for the local microenvironment and developmental origin of tissue macrophages in regulating self-renewal following alternative activating stimuli. Electronic supplementary material The online version of this article (10.1186/s12974-017-1011-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Giovanna Pepe
- Center of Excellence on Neurodegenerative Diseases and Department Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti, 9, 20133, Milan, Italy
| | - Marcella De Maglie
- Mouse and Animal Pathology Laboratory (MAPLab), Fondazione Filarete, Viale Ortles, 22/4, 20139, Milan, Italy.,Department of Veterinary Medicine, University of Milan, Via Celoria, 10, 20133, Milan, Italy
| | - Lucia Minoli
- Mouse and Animal Pathology Laboratory (MAPLab), Fondazione Filarete, Viale Ortles, 22/4, 20139, Milan, Italy.,Department of Veterinary Medicine, University of Milan, Via Celoria, 10, 20133, Milan, Italy
| | - Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases and Department Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti, 9, 20133, Milan, Italy
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases and Department Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti, 9, 20133, Milan, Italy
| | - Elisabetta Vegeto
- Center of Excellence on Neurodegenerative Diseases and Department Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti, 9, 20133, Milan, Italy.
| |
Collapse
|
37
|
Ahmed A, Wang LL, Abdelmaksoud S, Aboelgheit A, Saeed S, Zhang CL. Minocycline modulates microglia polarization in ischemia-reperfusion model of retinal degeneration and induces neuroprotection. Sci Rep 2017; 7:14065. [PMID: 29070819 PMCID: PMC5656679 DOI: 10.1038/s41598-017-14450-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/11/2017] [Indexed: 12/21/2022] Open
Abstract
Retinal ischemia-reperfusion (IR) injury causes irreversible loss of neurons and ultimately leads to permanent visual impairment and blindness. The cellular response under this pathological retinal condition is less clear. Using genetically modified mice, we systematically examined the behavior of microglia/macrophages after injury. We show that IR leads to activation of microglia/macrophages indicated by migration and proliferation of resident microglia and recruitment of circulating monocytes. IR-induced microglia/macrophages associate with apoptotic retinal neurons. Very interestingly, neuron loss can be mitigated by minocycline treatment. Minocycline induces Il4 expression and M2 polarization of microglia/macrophages. IL4 neutralization dampens minocycline-induced M2 polarization and neuroprotection. Given a well-established safety profile as an antibiotic, our results provide a rationale for using minocycline as a therapeutic agent for treating ischemic retinal degeneration.
Collapse
Affiliation(s)
- Amel Ahmed
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA.,Department of Histology and Cell Biology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Lei-Lei Wang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA
| | - Safaa Abdelmaksoud
- Department of Histology and Cell Biology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Amal Aboelgheit
- Department of Histology and Cell Biology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Safaa Saeed
- Department of Histology and Cell Biology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Chun-Li Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA. .,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, USA.
| |
Collapse
|
38
|
IL4-10 Fusion Protein Is a Novel Drug to Treat Persistent Inflammatory Pain. J Neurosci 2017; 36:7353-63. [PMID: 27413147 DOI: 10.1523/jneurosci.0092-16.2016] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/18/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Chronic pain is a major clinical problem that is difficult to treat and requires novel therapies. Although most pain therapies primarily target neurons, neuroinflammatory processes characterized by spinal cord and dorsal root ganglion production of proinflammatory cytokines play an important role in persistent pain states and represent potential therapeutic targets. Anti-inflammatory cytokines are attractive candidates to regulate aberrant neuroinflammatory processes, but the therapeutic potential of these cytokines as stand-alone drugs is limited. Their optimal function requires concerted actions with other regulatory cytokines, and their relatively small size causes rapid clearance. To overcome these limitations, we developed a fusion protein of the anti-inflammatory cytokines interleukin 4 (IL4) and IL10. The IL4-10 fusion protein is a 70 kDa glycosylated dimeric protein that retains the functional activity of both cytokine moieties. Intrathecal administration of IL4-10 dose-dependently inhibited persistent inflammatory pain in mice: three IL4-10 injections induced full resolution of inflammatory pain in two different mouse models of persistent inflammatory pain. Both cytokine moieties were required for optimal effects. The IL4-10 fusion protein was more effective than the individual cytokines or IL4 plus IL10 combination therapy and also inhibited allodynia in a mouse model of neuropathic pain. Mechanistically, IL4-10 inhibited the activity of glial cells and reduced spinal cord and dorsal root ganglion cytokine levels without affecting paw inflammation. In conclusion, we developed a novel fusion protein with improved efficacy to treat pain, compared with wild-type anti-inflammatory cytokines. The IL4-10 fusion protein has potential as a treatment for persistent inflammatory pain. SIGNIFICANCE STATEMENT The treatment of chronic pain is a major clinical and societal challenge. Current therapies to treat persistent pain states are limited and often cause major side effects. Therefore, novel analgesic treatments are urgently needed. In search of a novel drug to treat chronic pain, we developed a fusion protein consisting of two prototypic regulatory cytokines, interleukin 4 (IL4) and IL10. The work presented in this manuscript shows that this IL4-10 fusion protein overcomes some major therapeutic limitations of pain treatment with individual cytokines. The IL4-10 fusion protein induces full resolution of persistent inflammatory pain in two different mouse models. These novel findings are significant, as they highlight the IL4-10 fusion protein as a long-needed potential new drug to stop persistent pain states.
Collapse
|
39
|
Arcuri C, Mecca C, Bianchi R, Giambanco I, Donato R. The Pathophysiological Role of Microglia in Dynamic Surveillance, Phagocytosis and Structural Remodeling of the Developing CNS. Front Mol Neurosci 2017; 10:191. [PMID: 28674485 PMCID: PMC5474494 DOI: 10.3389/fnmol.2017.00191] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 05/30/2017] [Indexed: 12/13/2022] Open
Abstract
In vertebrates, during an early wave of hematopoiesis in the yolk sac between embryonic day E7.0 and E9.0, cells of mesodermal leaflet addressed to macrophage lineage enter in developing central nervous system (CNS) and originate the developing native microglial cells. Depending on the species, microglial cells represent 5–20% of glial cells resident in adult brain. Here, we briefly discuss some canonical functions of the microglia, i.e., cytokine secretion and functional transition from M1 to M2 phenotype. In addition, we review studies on the non-canonical functions of microglia such as regulation of phagocytosis, synaptic pruning, and sculpting postnatal neural circuits. In this latter context the contribution of microglia to some neurodevelopmental disorders is now well established. Nasu-Hakola (NHD) disease is considered a primary microgliopathy with alterations of the DNAX activation protein 12 (DAP12)-Triggering receptor expressed on myeloid cells 2 (TREM-2) signaling and removal of macromolecules and apoptotic cells followed by secondary microglia activation. In Rett syndrome Mecp2-/- microglia shows a substantial impairment of phagocytic ability, although the role of microglia is not yet clear. In a mouse model of Tourette syndrome (TS), microglia abnormalities have also been described, and deficient microglia-mediated neuroprotection is obvious. Here we review the role of microglial cells in neurodevelopmental disorders without inflammation and on the complex role of microglia in developing CNS.
Collapse
Affiliation(s)
- Cataldo Arcuri
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Carmen Mecca
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Roberta Bianchi
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Ileana Giambanco
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| | - Rosario Donato
- Department of Experimental Medicine, Centro Universitario per la Ricerca sulla Genomica Funzionale, Perugia Medical School, University of PerugiaPerugia, Italy
| |
Collapse
|
40
|
Xu C, Fu F, Li X, Zhang S. Mesenchymal stem cells maintain the microenvironment of central nervous system by regulating the polarization of macrophages/microglia after traumatic brain injury. Int J Neurosci 2017; 127:1124-1135. [PMID: 28464695 DOI: 10.1080/00207454.2017.1325884] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mesenchymal stem cells (MSCs), which are regarded as promising candidates for cell replacement therapies, are able to regulate immune responses after traumatic brain injury (TBI). Secondary immune response following the mechanical injury is the essential factor leading to the necrosis and apoptosis of neural cells during and after the cerebral edema has subsided and there is lack of efficient agent that can mitigate such neuroinflammation in the clinical application. By means of three molecular pathways (prostaglandin E2 (PGE2), tumor-necrosis-factor-inducible gene 6 protein (TSG-6), and progesterone receptor (PR) and glucocorticoid receptors (GR)), MSCs induce the activation of macrophages/microglia and drive them polarize into the M2 phenotypes, which inhibits the release of pro-inflammatory cytokines and promotes tissue repair and nerve regeneration. The regulation of MSCs and the polarization of macrophages/microglia are dynamically changing based on the inflammatory environment. Under the stimulation of platelet lysate (PL), MSCs also promote the release of pro-inflammatory cytokines. Meanwhile, the statue of macrophages/microglia exerts significant effects on the survival, proliferation, differentiation and activation of MSCs by changing the niche of cells. They form positive feedback loops in maintaining the homeostasis after TBI to relieving the secondary injury and promoting tissue repair. MSC therapies have obtained great achievements in several central nervous system disease clinical trials, which will accelerate the application of MSCs in TBI treatment.
Collapse
Affiliation(s)
- Chao Xu
- a Institute of Traumatic Brain Injury and Neurology, Pingjin Hospital , Logistics University of Chinese People's Armed Police Forces , Tianjin 300162 , China
| | - Feng Fu
- a Institute of Traumatic Brain Injury and Neurology, Pingjin Hospital , Logistics University of Chinese People's Armed Police Forces , Tianjin 300162 , China
| | - Xiaohong Li
- a Institute of Traumatic Brain Injury and Neurology, Pingjin Hospital , Logistics University of Chinese People's Armed Police Forces , Tianjin 300162 , China
| | - Sai Zhang
- a Institute of Traumatic Brain Injury and Neurology, Pingjin Hospital , Logistics University of Chinese People's Armed Police Forces , Tianjin 300162 , China
| |
Collapse
|
41
|
Liu YL, Chen WT, Lin YY, Lu PH, Hsieh SL, Cheng IHJ. Amelioration of amyloid-β-induced deficits by DcR3 in an Alzheimer's disease model. Mol Neurodegener 2017; 12:30. [PMID: 28438208 PMCID: PMC5402663 DOI: 10.1186/s13024-017-0173-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 04/07/2017] [Indexed: 12/03/2022] Open
Abstract
Background Microglia mediate amyloid-beta peptide (Aβ)-induced neuroinflammation, which is one of the key events in the pathogenesis of Alzheimer’s disease (AD). Decoy receptor 3 (DcR3)/TNFRSF6B is a pleiotropic immunomodulator that promotes macrophage differentiation toward the M2 anti-inflammatory phenotype. Based on its role as an immunosupressor, we examined whether DcR3 could alleviate neuroinflammation and AD-like deficits in the central nervous system. Method We crossed human APP transgenic mice (line J20) with human DcR3 transgenic mice to generate wild-type, APP, DcR3, and APP/DcR3 mice for pathological analysis. The Morris water maze, fear conditioning test, open-field, and elevated-plus maze were used to access their cognitive behavioral changes. Furthermore, the pathological and immune profiles were examined by immunostaining, ELISA, Q-PCR, and IP. In vitro assays were designed to examine DcR3-mediated innate cytokine profile alteration and the potential protective mechanism. Results We reported that DcR3 ameliorates hippocampus-dependent memory deficits and reduces amyloid plaque deposition in APP transgenic mouse. The protective mechanism of DcR3 mediates through interacting with heparan sulfate proteoglycans and activating IL-4+YM1+ M2a-like microglia that reduces Aβ-induced proinflammatory cytokines and promotes phagocytosis ability of microglia. Conclusion The neuroprotective effect of DcR3 is mediated via modulating microglia activation into anti-inflammatory M2a phenotype, and upregulating DcR3 expression in the brain may be a potential therapeutic approach for AD. Electronic supplementary material The online version of this article (doi:10.1186/s13024-017-0173-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Yi-Ling Liu
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Wei-Ting Chen
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Yi Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Po-Hung Lu
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan
| | - Shie-Liang Hsieh
- Genomics Research Center, Academia Sinica, Taipei, Taiwan. .,Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan. .,Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan. .,Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan.
| | - Irene Han-Juo Cheng
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan. .,Brain Research Center, National Yang-Ming University, Taipei, Taiwan. .,Infection and Immunity Research Center, National Yang-Ming University, Taipei, Taiwan.
| |
Collapse
|
42
|
Hühner L, Rilka J, Gilsbach R, Zhou X, Machado V, Spittau B. Interleukin-4 Protects Dopaminergic Neurons In vitro but Is Dispensable for MPTP-Induced Neurodegeneration In vivo. Front Mol Neurosci 2017; 10:62. [PMID: 28337124 PMCID: PMC5343015 DOI: 10.3389/fnmol.2017.00062] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/24/2017] [Indexed: 01/10/2023] Open
Abstract
Microglia are involved in physiological as well as neuropathological processes in the central nervous system (CNS). Their functional states are often referred to as M1-like and M2-like activation, and are believed to contribute to neuroinflammation-mediated neurodegeneration or neuroprotection, respectively. Parkinson’s disease (PD) is one the most common neurodegenerative disease and is characterized by the progressive loss of midbrain dopaminergic (mDA) neurons in the substantia nigra resulting in bradykinesia, tremor, and rigidity. Interleukin 4 (IL4)-mediated M2-like activation of microglia, which is characterized by upregulation of alternative markers Arginase 1 (Arg1) and Chitinase 3 like 3 (Ym1) has been well studied in vitro but the role of endogenous IL4 during CNS pathologies in vivo is not well understood. Interestingly, microglia activation by IL4 has been described to promote neuroprotective and neurorestorative effects, which might be important to slow the progression of neurodegenerative diseases. In the present study, we addressed the role of endogenous and exogenous IL4 during MPP+-induced degeneration of mDA neurons in vitro and further addressed the impact of IL4-deficiency on neurodegeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD in vivo. Our results clearly demonstrate that exogenous IL4 is important to protect mDA neurons in vitro, but endogenous IL4 seems to be dispensable for development and maintenance of the nigrostriatal system as well as MPTP-induced loss of TH+ neurons in vivo. These results underline the importance of IL4 in promoting a neuroprotective microglia activation state and strengthen the therapeutic potential of exogenous IL4 for protection of mDA neurons in PD models.
Collapse
Affiliation(s)
- Laura Hühner
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg Freiburg, Germany
| | - Jennifer Rilka
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg Freiburg, Germany
| | - Ralf Gilsbach
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Freiburg Freiburg, Germany
| | - Xiaolai Zhou
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Faculty of Medicine, University of FreiburgFreiburg, Germany; Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, IthacaNY, USA
| | - Venissa Machado
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg Freiburg, Germany
| | - Björn Spittau
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg Freiburg, Germany
| |
Collapse
|
43
|
Littlefield A, Kohman RA. Differential response to intrahippocampal interleukin-4/interleukin-13 in aged and exercise mice. Neuroscience 2016; 343:106-114. [PMID: 27916728 DOI: 10.1016/j.neuroscience.2016.11.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/28/2016] [Accepted: 11/21/2016] [Indexed: 01/08/2023]
Abstract
Normal aging is associated with low-grade neuroinflammation that results from age-related priming of microglial cells. Further, aging alters the response to several anti-inflammatory factors, including interleukin (IL)-4 and IL-13. One intervention that has been shown to modulate microglia activation in the aged brain, both basally and following an immune challenge, is exercise. However, whether engaging in exercise can improve responsiveness to anti-inflammatory cytokines is presently unknown. The current study evaluated whether prior exercise training increases sensitivity to anti-inflammatory cytokines that promote the M2 (alternative) microglia phenotype in adult (5-month-old) and aged (23-month-old) C57BL/6J mice. After 8weeks of exercise or control housing, mice received bilateral hippocampal injections of an IL-4/IL-13 cocktail or vehicle. Twenty-four hours later hippocampal samples were collected and analyzed for expression of genes associated with the M1 (inflammatory) and M2 microglia phenotypes. Results show that IL-4/IL-13 administration increased expression of the M2-associated genes found in inflammatory zone 1 (Fizz1), chitinase-like 3 (Ym1), Arginase-1 (Arg1), SOCS1, IL-1ra, and CD206. In response to IL-4/IL-13 administration, aged mice showed increased hippocampal expression of the M2-related genes Arg1, SOCS1, Ym1, and CD206 relative to adult mice. Aged mice also showed increased expression of IL-1β relative to adults, which was unaffected by wheel running or IL-4/IL-13. Wheel running was found to have modest effects on expression of Ym1 and Fizz1 in aged and adult mice. Collectively, our findings indicate that aged mice show a differential response to anti-inflammatory cytokines relative to adult mice and that exercise has limited effects on modulating this response.
Collapse
Affiliation(s)
- Alyssa Littlefield
- University of North Carolina Wilmington, Department of Psychology, Wilmington, NC, USA; Rosalind Franklin University of Medicine and Science, Department of Neuroscience, North Chicago, IL, USA.
| | - Rachel A Kohman
- University of North Carolina Wilmington, Department of Psychology, Wilmington, NC, USA.
| |
Collapse
|
44
|
Lively S, Hutchings S, Schlichter LC. Molecular and Cellular Responses to Interleukin-4 Treatment in a Rat Model of Transient Ischemia. J Neuropathol Exp Neurol 2016; 75:1058-1071. [PMID: 27634961 PMCID: PMC5070459 DOI: 10.1093/jnen/nlw081] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Within hours after stroke, potentially cytotoxic pro-inflammatory mediators are elevated within the brain; thus, one potential therapeutic strategy is to reduce them and skew the brain toward an anti-inflammatory state. Because interleukin-4 (IL-4) treatment induces an anti-inflammatory, "alternative-activation" state in microglia and macrophages in vitro, we tested the hypothesis that early supplementation of the brain with IL-4 can shift it toward an anti-inflammatory state and reduce damage after transient focal ischemia. Adult male rat striata were injected with endothelin-1, with or without co-injection of IL-4. Inflammation, glial responses and damage to neurons and white matter were quantified from 1 to 7 days later. At 1 day, IL-4 treatment increased striatal expression of several anti-inflammatory markers (ARG1, CCL22, CD163, PPARγ), increased phagocytic (Iba1-positive, CD68-positive) microglia/macrophages, and increased VEGF-A-positive infiltrating neutrophils in the infarcts. At 7 days, there was evidence of sustained, propagating responses. IL-4 increased CD206, CD200R1, IL-4Rα, STAT6, PPARγ, CD11b, and TLR2 expression and increased microglia/macrophages in the infarct and astrogliosis outside the infarct. Neurodegeneration and myelin damage were not reduced, however. The sustained immune and glial responses when resolution and repair processes have begun warrant further studies of IL-4 treatment regimens and long-term outcomes.
Collapse
Affiliation(s)
- Starlee Lively
- From the Krembil Research Institute, University Health Network, Toronto, ON, Canada (SL, SH, LCS); Department of Physiology, University of Toronto, Toronto, ON, Canada (SH, LCS)
| | - Sarah Hutchings
- From the Krembil Research Institute, University Health Network, Toronto, ON, Canada (SL, SH, LCS); Department of Physiology, University of Toronto, Toronto, ON, Canada (SH, LCS)
| | - Lyanne C Schlichter
- From the Krembil Research Institute, University Health Network, Toronto, ON, Canada (SL, SH, LCS); Department of Physiology, University of Toronto, Toronto, ON, Canada (SH, LCS)
| |
Collapse
|
45
|
Abstract
Inflammatory activation of microglia is a hallmark of several disorders of the central nervous system. In addition to protecting the brain against inflammatory insults, microglia are neuroprotective and play a significant role in maintaining neuronal connectivity, but the prolongation of an inflammatory status may limit the beneficial functions of these immune cells. The finding that estrogen receptors are present in monocyte-derived cells and that estrogens prevent and control the inflammatory response raise the question of the role that this sex steroid plays in the manifestation and progression of pathologies that have a clear sex difference in prevalence, such as multiple sclerosis, Parkinson's disease, and Alzheimer's disease. The present review aims to provide a critical review of the current literature on the actions of estrogen in microglia and on the involvement of estrogen receptors in the manifestation of selected neurological disorders. This current understanding highlights a research area that should be expanded to identify appropriate replacement therapies to slow the progression of such diseases.
Collapse
Affiliation(s)
- Alessandro Villa
- Center of Excellence on Neurodegenerative Diseases and Department of Pharmacological and Biomolecular Sciences, University of Milan, 20133 Milan, Italy
| | - Elisabetta Vegeto
- Center of Excellence on Neurodegenerative Diseases and Department of Pharmacological and Biomolecular Sciences, University of Milan, 20133 Milan, Italy
| | - Angelo Poletti
- Center of Excellence on Neurodegenerative Diseases and Department of Pharmacological and Biomolecular Sciences, University of Milan, 20133 Milan, Italy
| | - Adriana Maggi
- Center of Excellence on Neurodegenerative Diseases and Department of Pharmacological and Biomolecular Sciences, University of Milan, 20133 Milan, Italy
| |
Collapse
|
46
|
Russo R, Varano GP, Adornetto A, Nucci C, Corasaniti MT, Bagetta G, Morrone LA. Retinal ganglion cell death in glaucoma: Exploring the role of neuroinflammation. Eur J Pharmacol 2016; 787:134-42. [PMID: 27044433 DOI: 10.1016/j.ejphar.2016.03.064] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 03/10/2016] [Accepted: 03/31/2016] [Indexed: 01/06/2023]
Abstract
In clinical glaucoma, as well as in experimental models, the loss of retinal ganglion cells occurs by apoptosis. This final event is preceded by inflammatory responses involving the activation of innate and adaptive immunity, with retinal and optic nerve resident glial cells acting as major players. Here we review the current literature on the role of neuroinflammation in neurodegeneration, focusing on the inflammatory molecular mechanisms involved in the pathogenesis and progression of the optic neuropathy.
Collapse
Affiliation(s)
- Rossella Russo
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy.
| | - Giuseppe Pasquale Varano
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Annagrazia Adornetto
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome Italy
| | | | - Giacinto Bagetta
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy; University Center for Adaptive Disorders and Head Pain, Section of Neuropharmacology of Normal and Pathological Neuronal Plasticity, University of Calabria, Arcavacata di Rende, Italy
| | - Luigi Antonio Morrone
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Arcavacata di Rende, Italy; University Center for Adaptive Disorders and Head Pain, Section of Neuropharmacology of Normal and Pathological Neuronal Plasticity, University of Calabria, Arcavacata di Rende, Italy
| |
Collapse
|
47
|
A(H1N1) vaccination recruits T lymphocytes to the choroid plexus for the promotion of hippocampal neurogenesis and working memory in pregnant mice. Brain Behav Immun 2016; 53:72-83. [PMID: 26576725 DOI: 10.1016/j.bbi.2015.11.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 10/30/2015] [Accepted: 11/09/2015] [Indexed: 12/20/2022] Open
Abstract
We previously demonstrated that A(H1N1) influenza vaccine (AIV) promoted hippocampal neurogenesis and working memory in pregnant mice. However, the underlying mechanism of flu vaccination in neurogenesis and memory has remained unclear. In this study, we found that T lymphocytes were recruited from the periphery to the choroid plexus (CP) of the lateral and third (3rd) ventricles in pregnant mice vaccinated with AIV (Pre+AIV). Intracerebroventricular delivery of anti-TCR antibodies markedly decreased neurogenesis and the working memory of the Pre+AIV mice. Similarly, intravenous delivery of anti-CD4 antibodies to the periphery also down-regulated neurogenesis. Furthermore, AIV vaccination caused microglia to skew toward an M2-like phenotype (increased Arginase-1 and Ym1 mRNA levels), and elevated levels of brain-derived growth factor (BDNF) and insulin-like growth factor-1 (IGF-1) were found in the hippocampus, whereas these effects were offset by anti-TCR antibody treatment. Additionally, in the CP, the expression level of adhesion molecules and chemokines, which assist leukocytes in permeating into the brain, were also elevated after AIV vaccination of pregnant mice. Collectively, the results suggested that the infiltrative T lymphocytes in the CP contribute to the increase in hippocampal neurogenesis and working memory caused by flu vaccination, involving activation of the brain's CP, M2 microglial polarization and neurotrophic factor expression.
Collapse
|
48
|
Norden DM, Trojanowski PJ, Villanueva E, Navarro E, Godbout JP. Sequential activation of microglia and astrocyte cytokine expression precedes increased Iba-1 or GFAP immunoreactivity following systemic immune challenge. Glia 2016; 64:300-16. [PMID: 26470014 PMCID: PMC4707977 DOI: 10.1002/glia.22930] [Citation(s) in RCA: 377] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 09/16/2015] [Accepted: 09/22/2015] [Indexed: 12/11/2022]
Abstract
Activation of the peripheral immune system elicits a coordinated response from the central nervous system. Key to this immune to brain communication is that glia, microglia, and astrocytes, interpret and propagate inflammatory signals in the brain that influence physiological and behavioral responses. One issue in glial biology is that morphological analysis alone is used to report on glial activation state. Therefore, our objective was to compare behavioral responses after in vivo immune (lipopolysaccharide, LPS) challenge to glial specific mRNA and morphological profiles. Here, LPS challenge induced an immediate but transient sickness response with decreased locomotion and social interaction. Corresponding with active sickness behavior (2-12 h), inflammatory cytokine mRNA expression was elevated in enriched microglia and astrocytes. Although proinflammatory cytokine expression in microglia peaked 2-4 h after LPS, astrocyte cytokine, and chemokine induction was delayed and peaked at 12 h. Morphological alterations in microglia (Iba-1(+)) and astrocytes (GFAP(+)), however, were undetected during this 2-12 h timeframe. Increased Iba-1 immunoreactivity and de-ramified microglia were evident 24 and 48 h after LPS but corresponded to the resolution phase of activation. Morphological alterations in astrocytes were undetected after LPS. Additionally, glial cytokine expression did not correlate with morphology after four repeated LPS injections. In fact, repeated LPS challenge was associated with immune and behavioral tolerance and a less inflammatory microglial profile compared with acute LPS challenge. Overall, induction of glial cytokine expression was sequential, aligned with active sickness behavior, and preceded increased Iba-1 or GFAP immunoreactivity after LPS challenge.
Collapse
Affiliation(s)
- Diana M. Norden
- Department of Neuroscience, The Ohio State University, 333 W. 10 Ave, Columbus, OH 43210, USA
| | - Paige J. Trojanowski
- Department of Neuroscience, The Ohio State University, 333 W. 10 Ave, Columbus, OH 43210, USA
| | - Emmanuel Villanueva
- Department of Neuroscience, The Ohio State University, 333 W. 10 Ave, Columbus, OH 43210, USA
| | - Elisa Navarro
- Department of Neuroscience, The Ohio State University, 333 W. 10 Ave, Columbus, OH 43210, USA
| | - Jonathan P. Godbout
- Department of Neuroscience, The Ohio State University, 333 W. 10 Ave, Columbus, OH 43210, USA
- Institute for Behavioral Medicine Research, The Ohio State University, 460 Medical Center Dr., Columbus, OH 43210, USA
- Corresponding author: J.P. Godbout, 259 IBMR Bldg, 460 Medical Center Dr., The Ohio State University, Columbus, OH 43210, USA. Tel: (614) 293-3456 Fax: (614) 366-2097,
| |
Collapse
|
49
|
Ghosh M, Xu Y, Pearse DD. Cyclic AMP is a key regulator of M1 to M2a phenotypic conversion of microglia in the presence of Th2 cytokines. J Neuroinflammation 2016; 13:9. [PMID: 26757726 PMCID: PMC4711034 DOI: 10.1186/s12974-015-0463-9] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/17/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Microglia and macrophages play a central role in neuroinflammation. Pro-inflammatory cytokines trigger their conversion to a classically activated (M1) phenotype, sustaining inflammation and producing a cytotoxic environment. Conversely, anti-inflammatory cytokines polarize the cells towards an alternatively activated (M2), tissue reparative phenotype. Elucidation of the signal transduction pathways involved in M1 to M2 phenotypic conversion may provide insight into how the innate immune response can be harnessed during distinct phases of disease or injury to mediate neuroprotection and neurorepair. METHODS Microglial cells (cell line and primary) were subjected to combined cyclic adenosine monophosphate (cyclic AMP) and IL-4, or either alone, in the presence of pro-inflammatory mediators, lipopolysaccharide (LPS), or tumor necrosis factor-α (TNF-α). Their effects on the expression of characteristic markers for M1 and M2 microglia were assessed. Similarly, the M1 and M2 phenotypes of microglia and macrophages within the lesion site were then evaluated following a contusive spinal cord injury (SCI) to the thoracic (T8) spinal cord of rats and mice when the agents were administered systemically. RESULTS It was demonstrated that cyclic AMP functions synergistically with IL-4 to promote M1 to M2 conversion of microglia in culture. The combination of cyclic AMP and IL-4, but neither alone, induced an Arg-1(+)/iNOS(-)cell phenotype with concomitant expression of other M2-specific markers including TG2 and RELM-α. M2-converted microglia showed ameliorated production of pro-inflammatory cytokines (TNF-α and IP-10) and reactive oxygen species, with no alteration in phagocytic properties. M2a conversion required protein kinase A (PKA), but not the exchange protein directly activated by cyclic AMP (EPAC). Systemic delivery of cyclic AMP and IL-4 after experimental SCI also promoted a significant M1 to M2a phenotypic change in microglia and macrophage population dynamics in the lesion. CONCLUSIONS Using primary microglia, microglial cell lines, and experimental models of CNS injury, we demonstrate that cyclic AMP levels are a critical determinant in M1-M2 polarization. High levels of cyclic AMP promoted an Arg-1(+) M2a phenotype when microglia were activated with pro-inflammatory stimuli and Th2 cytokines. Th2 cytokines or cyclic AMP independently did not promote these changes. Phenotypic conversion of microglia provides a powerful new therapeutic approach for altering the balance of cytotoxic to reparative microglia in a diversity of neurological diseases and injury.
Collapse
Affiliation(s)
- Mousumi Ghosh
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. .,Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - Yong Xu
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - Damien D Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. .,Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. .,The Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL, 33136, USA. .,The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| |
Collapse
|
50
|
Peña-Altamira E, Prati F, Massenzio F, Virgili M, Contestabile A, Bolognesi ML, Monti B. Changing paradigm to target microglia in neurodegenerative diseases: from anti-inflammatory strategy to active immunomodulation. Expert Opin Ther Targets 2015; 20:627-40. [PMID: 26568363 DOI: 10.1517/14728222.2016.1121237] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The importance of microglia in most neurodegenerative pathologies, from Parkinson's disease to amyotrophic lateral sclerosis and Alzheimer's disease, is increasingly recognized. Until few years ago, microglial activation in pathological conditions was considered dangerous to neurons due to its causing inflammation. Today we know that these glial cells also play a crucial physiological and neuroprotective role, which is altered in neurodegenerative conditions. AREAS COVERED The neuroinflammatory hypothesis for neurodegenerative diseases has led to the trial of anti-inflammatory agents as therapeutics with largely disappointing results. New information about the physiopathological role of microglia has highlighted the importance of immunomodulation as a potential new therapeutic approach. This review summarizes knowledge on microglia as a potential therapeutic target in the most common neurodegenerative diseases, with focus on compounds directed toward the modulation of microglial immune response through specific molecular pathways. EXPERT OPINION Here we support the innovative concept of targeting microglial cells by modulating their activity, rather than simply trying to counteract their inflammatory neurotoxicity, as a potential therapeutic approach for neurodegenerative diseases. The advantage of this therapeutic approach could be to reduce neuroinflammation and toxicity, while at the same time strengthening intrinsic neuroprotective properties of microglia and promoting neuroregeneration.
Collapse
Affiliation(s)
| | - Federica Prati
- a Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| | - Francesca Massenzio
- a Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| | - Marco Virgili
- a Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| | - Antonio Contestabile
- a Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| | - Maria Laura Bolognesi
- a Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| | - Barbara Monti
- a Department of Pharmacy and Biotechnology , University of Bologna , Bologna , Italy
| |
Collapse
|