Neuropathic pain occurs after several diseases accompanied by nerve damage, which is characterized by abnormal sensory perception such as tactile allodynia (nocuous response to innocuous mechanical stimuli). This debilitating pain condition arises as a consequence of excessive excitability of neurons in the spinal dorsal horn, and the neuronal hyperexcitability involves signaling from activated spinal microglia that have induced or enhanced expression of various genes including proinflammatory cytokines. However, a key transcription factor regulating gene expression and neuropathic pain states is not identified. Here we report that interferon regulatory factor-8 (IRF-8), a member of IRF family transcription factor, controls gene expression in activated microglia responsible for tactile allodynia. Peripheral nerve injury (PNI) increased the expression of IRF-8 in spinal microglia in a cell type-specific manner. Furthermore, IRF-8-deficient mice (irf8-/-) exhibited a marked reduction in allodynia after PNI compared with wild-type mice without affecting normal pain sensitivity. In contrast, these mice showed a similar pain behavior in an inflammatory chronic pain model. Interestingly, irf8-/- mice failed to increase the expression of genes crucial for producing pain hypersensitivity in the spinal cord following PNI. Together, our present findings suggest that IRF-8 is the crucial intermediary for upregulating pain-related molecules and subsequent neuropathic pain.

Authorship：Lead author   Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41586-019-0924-x

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DOI： 10.1038/ncomms12529

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DOI： 10.1038/ncomms4771

DOI： 10.7554/eLife.105087.1

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Neurochemistry  

Stress is a significant cause of mental disorders, for which effective treatments remain limited due to an insufficient understanding of its pathogenic mechanisms. Recent research has increasingly focused on non-neuronal cells to elucidate the molecular mechanisms underlying psychopathology. In this review, we summarize the current knowledge on how non-neuronal cells in the central nervous system, including microglia, astrocytes, and oligodendrocytes, respond to peripherally derived stress-related factors and how these responses contribute to the development of mental disorders. A more comprehensive understanding of stress-induced alterations, with careful consideration of the type and timing of stress exposure, will provide fundamental insights into the pathogenesis of diverse stress-related mental disorders. (Figure presented.).

DOI： 10.1111/jnc.16262

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Science Immunology  

Although macrophages in the meningeal compartments of the central nervous system (CNS) have been comprehensively characterized under steady state, studying their contribution to physiological and pathological processes has been hindered by the lack of specific targeting tools in vivo. Recent findings have shown that the dural sinus and its adjacent lymphatic vessels act as a neuroimmune interface. However, the cellular and functional heterogeneity of extrasinusoidal dural macrophages outside this immune hub is not fully understood. Therefore, we comprehensively characterized these cells using single-cell transcriptomics, fate mapping, confocal imaging, clonal analysis, and transgenic mouse lines. Extrasinusoidal dural macrophages were distinct from leptomeningeal and CNS parenchymal macrophages in terms of their origin, expansion kinetics, and transcriptional profiles. During autoimmune neuroinflammation, extrasinusoidal dural macrophages performed efferocytosis of apoptotic granulocytes. Our results highlight a previously unappreciated myeloid cell diversity and provide insights into the brain’s innate immune system.

DOI： 10.1126/sciimmunol.adh1129

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Neuroinflammation  

BACKGROUND: The eye is a highly specialized sensory organ which encompasses the retina as a part of the central nervous system, but also non-neural compartments such as the transparent vitreous body ensuring stability of the eye globe and a clear optical axis. Hyalocytes are the tissue-resident macrophages of the vitreous body and are considered to play pivotal roles in health and diseases of the vitreoretinal interface, such as proliferative vitreoretinopathy or diabetic retinopathy. However, in contrast to other ocular macrophages, their embryonic origin as well as the extent to which these myeloid cells might be replenished by circulating monocytes remains elusive. RESULTS: In this study, we combine transgenic reporter mice, embryonic and adult fate mapping approaches as well as parabiosis experiments with multicolor immunofluorescence labeling and confocal laser-scanning microscopy to comprehensively characterize the murine hyalocyte population throughout development and in adulthood. We found that murine hyalocytes express numerous well-known myeloid cell markers, but concomitantly display a distinct immunophenotype that sets them apart from retinal microglia. Embryonic pulse labeling revealed a yolk sac-derived origin of murine hyalocytes, whose precursors seed the developing eye prenatally. Finally, postnatal labeling and parabiosis established the longevity of hyalocytes which rely on Colony Stimulating Factor 1 Receptor (CSF1R) signaling for their maintenance, independent of blood-derived monocytes. CONCLUSION: Our study identifies hyalocytes as long-living progeny of the yolk sac hematopoiesis and highlights their role as integral members of the innate immune system of the eye. As a consequence of their longevity, immunosenescence processes may culminate in hyalocyte dysfunction, thereby contributing to the development of vitreoretinal diseases. Therefore, myeloid cell-targeted therapies that convey their effects through the modification of hyalocyte properties may represent an interesting approach to alleviate the burden imposed by diseases of the vitreoretinal interface.

DOI： 10.1186/s12974-024-03110-x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Molecular Brain  

CD11c-positive (CD11c+) microglia have attracted considerable attention because of their potential implications in central nervous system (CNS) development, homeostasis, and disease. However, the spatiotemporal dynamics of the proportion of CD11c+ microglia in individual CNS regions are poorly understood. Here, we investigated the proportion of CD11c+ microglia in six CNS regions (forebrain, olfactory bulb, diencephalon/midbrain, cerebellum, pons/medulla, and spinal cord) from the developmental to adult stages by flow cytometry and immunohistochemical analyses using a CD11c reporter transgenic mouse line, Itgax-Venus. We found that the proportion of CD11c+ microglia in total microglia varied between CNS regions during postnatal development. Specifically, the proportion was high in the olfactory bulb and cerebellum at postnatal day P(4) and P7, respectively, and approximately half of the total microglia were CD11c+. The proportion declined sharply in all regions to P14, and the low percentage persisted over P56. In the spinal cord, the proportion of CD11c+ microglia was also high at P4 and declined to P14, but increased again at P21 and thereafter. Interestingly, the distribution pattern of CD11c+ microglia in the spinal cord markedly changed from gray matter at P4 to white matter at P21. Collectively, our findings reveal the differences in the spatiotemporal dynamics of the proportion of CD11c+ microglia among CNS regions from early development to adult stages in normal mice. These findings improve our understanding of the nature of microglial heterogeneity and its dynamics in the CNS.

DOI： 10.1186/s13041-024-01098-2

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Clinical and Experimental Neuroimmunology  

Blood–tissue barriers play crucial roles in specialized tissues such as the central nervous system (CNS), eye, testis, and placenta. Tissue-resident macrophages in these tissues are indispensable for maintaining tissue homeostasis and responding to pathological conditions. Recent advances in high-throughput and high-dimensional single-cell analysis techniques, coupled with fate-mapping tools, have revealed a remarkable diversity of tissue-resident macrophages at the blood–tissue barrier. However, while comprehensive expression profiling has revealed the heterogeneity of macrophages within individual tissues, the commonalities of macrophages across anatomically similar structures like blood–tissue barriers remain poorly understood. This review focuses on the diversity and functional specialization of macrophages in tissues with blood–tissue barriers, highlighting recent insights into their anatomical distribution, developmental origins, phenotypic characteristics, and roles in maintaining tissue homeostasis. These findings may deepen our understanding of macrophage adaptation mechanisms in tissues with blood–tissue barriers, potentially leading to improved therapies for related disorders. Furthermore, examining the similarities and differences of macrophages across tissues may elucidate the molecular underpinnings of tissue-specific adaptation mechanisms and functional specialization.

DOI： 10.1111/cen3.12812

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Proceedings of the National Academy of Sciences of the United States of America  

Although generating new neurons in the ischemic injured brain would be an ideal approach to replenish the lost neurons for repairing the damage, the adult mammalian brain retains only limited neurogenic capability. Here, we show that direct conversion of microglia/macrophages into neurons in the brain has great potential as a therapeutic strategy for ischemic brain injury. After transient middle cerebral artery occlusion in adult mice, microglia/macrophages converge at the lesion core of the striatum, where neuronal loss is prominent. Targeted expression of a neurogenic transcription factor, NeuroD1, in microglia/macrophages in the injured striatum enables their conversion into induced neuronal cells that functionally integrate into the existing neuronal circuits. Furthermore, NeuroD1-mediated induced neuronal cell generation significantly improves neurological function in the mouse stroke model, and ablation of these cells abolishes the gained functional recovery. Our findings thus demonstrate that neuronal conversion contributes directly to functional recovery after stroke.

DOI： 10.1073/pnas.2307972120

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Cell Reports  

Cre/loxP technology has revolutionized genetic studies and allowed for spatial and temporal control of gene expression in specific cell types. Microglial biology has particularly benefited because microglia historically have been difficult to transduce with virus or electroporation methods for gene delivery. Here, we investigate five of the most widely available microglial inducible Cre lines. We demonstrate varying degrees of recombination efficiency, cell-type specificity, and spontaneous recombination, depending on the Cre line and inter-loxP distance. We also establish best practice guidelines and protocols to measure recombination efficiency, particularly in microglia. There is increasing evidence that microglia are key regulators of neural circuits and major drivers of a broad range of neurological diseases. Reliable manipulation of their function in vivo is of utmost importance. Identifying caveats and benefits of all tools and implementing the most rigorous protocols are crucial to the growth of the field and the development of microglia-based therapeutics.

DOI： 10.1016/j.celrep.2023.113031

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Inflammation and Regeneration  

Microglia are resident macrophages in the central nervous system (CNS) that play various roles during brain development and in the pathogenesis of CNS diseases. Recently, reprogramming of cellular energetic metabolism in microglia has drawn attention as a crucial mechanism for diversification of microglial functionality. Lipids are highly diverse materials and crucial components of cell membranes in every cell. Accumulating evidence has shown that lipid and its metabolism are tightly involved in microglial biology. In this review, we summarize the current knowledge about microglial lipid metabolism in health and disease.

DOI： 10.1186/s41232-023-00289-z

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publisher：The Japanese Pharmacological Society  

DOI： 10.1254/fpj.22153

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publisher：The Japanese Pharmacological Society  

<p>The central nervous system (CNS) is a highly complex collection of various cell-types, such as neurons, glial cells, vascular cells, and immune cells, and their complex and dynamic interactions enable to achieve highly sophisticated functions of the CNS. Among such CNS cells are microglia, which are well-known primary CNS macrophages localized in the CNS parenchyma and play a pivotal role in the maintenance of tissue homeostasis. Besides microglia, there are anatomically distinct macrophage populations at the border of the CNS, such as meninge, and perivascular space, called CNS-associated macrophages (CAMs). Recent studies have given novel insights into the nature of CAMs. In this review, I will discuss our current knowledge of the origins, the cellular properties of CNS macrophages.</p>

DOI： 10.1254/fpj.22152

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Genes to Cells  

Neuronal regeneration to replenish lost neurons after injury is critical for brain repair. Microglia, brain-resident macrophages that have the propensity to accumulate at the site of injury, can be a potential source for replenishing lost neurons through fate conversion into neurons, induced by forced expression of neuronal lineage-specific transcription factors. However, it has not been strictly demonstrated that microglia, rather than central nervous system-associated macrophages, such as meningeal macrophages, convert into neurons. Here, we show that NeuroD1-transduced microglia can be successfully converted into neurons in vitro using lineage-mapping strategies. We also found that a chemical cocktail treatment further promoted NeuroD1-induced microglia-to-neuron conversion. NeuroD1 with loss-of-function mutation, on the other hand, failed to induce the neuronal conversion. Our results indicate that microglia are indeed reprogrammed into neurons by NeuroD1 with neurogenic transcriptional activity.

DOI： 10.1111/gtc.13033

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Microglia play pivotal roles in controlling CNS functions in diverse physiological and pathological contexts, including neuropathic pain, a chronic pain condition caused by lesions or diseases of the somatosensory nervous system. In this review article, we summarize evidence primarily from basic research on the role of microglia in the development and remission of neuropathic pain. The identification of a subset of microglia that emerged after pain development and that was necessary for remission of neuropathic pain highlights the highly divergent and dynamic nature of microglia in the course of neuropathic pain. Understanding microglial diversity in terms of gene expression, physiological states, and functional roles could lead to new strategies that aid in the diagnosis and management of neuropathic pain, and that may not have been anticipated from the viewpoint of targeting all microglia uniformly.

DOI： 10.1016/j.tins.2023.05.001

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Authorship：Lead author,　Last author,　Corresponding author   Publisher：Gan to kagaku ryoho. Cancer &amp; chemotherapy  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Neuroscience  

Microglia, the resident immune cells of the CNS, sense the activity of neurons and regulate physiological brain functions. They have been implicated in the pathology of brain diseases associated with alterations in neural excitability and plasticity. However, experimental and therapeutic approaches that modulate microglia function in a brain region-specific manner have not been established. In this study, we tested for the effects of repetitive transcranial magnetic stimulation (rTMS), a clinically used noninvasive brain stimulation technique, on microglia-mediated synaptic plasticity; 10Hz electromagnetic stimulation triggered a release of plasticity-promoting cytokines from microglia in mouse organotypic brain tissue cultures of both sexes, while no significant changes in microglial morphology or microglia dynamics were observed. Indeed, substitution of tumor necrosis factor a (TNFa) and interleukin 6 (IL6) preserved synaptic plasticity induced by 10Hz stimulation in the absence of microglia. Consistent with these findings, in vivo depletion of microglia abolished rTMS-induced changes in neurotransmission in the mPFC of anesthetized mice of both sexes. We conclude that rTMS affects neural excitability and plasticity by modulating the release of cytokines from microglia.

DOI： 10.1523/JNEUROSCI.2226-22.2023

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Authorship：Lead author,　Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Biochemistry  

The central nervous system (CNS) is a highly complex collection of neurons with a variety of stromal cells, such as glia cells, immune cells, vascular cells and fibroblasts. Microglia are a resident macrophage and a type of glial cells located in the parenchyma of the CNS and play a pivotal role in the maintenance of tissue homeostasis. They are early responders to the abnormality of the CNS, leading to the adaptation of their phenotypes by virtue of their plasticity, after which they give an impact on neuronal functions. Besides microglia, there are anatomically and phenotypically distinct macrophage populations at the border of the CNS, such as meninge, perivascular space and choroid plexus, where they show distinct morphology and gene expression profiles when compared with microglia. This review will summarize the recent advance in our knowledge regarding their heterogeneity, plasticity, ontogenetic relationship of these CNS-resident macrophage populations.

DOI： 10.1093/jb/mvac093

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Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Cell Reports  

The relationships between tissue-resident microglia and early macrophages, especially their lineage segregation outside the yolk sac, have been recently explored, providing a model in which a conversion from macrophages seeds microglia during brain development. However, spatiotemporal evidence to support such microglial seeding in situ and to explain how it occurs has not been obtained. By cell tracking via slice culture, intravital imaging, and Flash tag-mediated or genetic labeling, we find that intraventricular CD206+ macrophages, which are abundantly observed along the inner surface of the mouse cerebral wall, frequently enter the pallium at embryonic day 12. Immunofluorescence of the tracked cells show that postinfiltrative macrophages in the pallium acquire microglial properties while losing the CD206+ macrophage phenotype. We also find that intraventricular macrophages are supplied transepithelially from the roof plate. This study demonstrates that the "roof plate→ventricle→pallium" route is an essential path for microglial colonization into the embryonic mouse brain.

DOI： 10.1016/j.celrep.2023.112092

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DOI： 10.1101/2023.01.09.523268

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Neuron  

Microglial research has advanced considerably in recent decades yet has been constrained by a rolling series of dichotomies such as “resting versus activated” and “M1 versus M2.” This dualistic classification of good or bad microglia is inconsistent with the wide repertoire of microglial states and functions in development, plasticity, aging, and diseases that were elucidated in recent years. New designations continuously arising in an attempt to describe the different microglial states, notably defined using transcriptomics and proteomics, may easily lead to a misleading, although unintentional, coupling of categories and functions. To address these issues, we assembled a group of multidisciplinary experts to discuss our current understanding of microglial states as a dynamic concept and the importance of addressing microglial function. Here, we provide a conceptual framework and recommendations on the use of microglial nomenclature for researchers, reviewers, and editors, which will serve as the foundations for a future white paper.

DOI： 10.1016/j.neuron.2022.10.020

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Clin Transl Med  

DOI： 10.1002/ctm2.1096

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DOI： 10.15252/embj.2020105123

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DOI： 10.1038/s41593-020-0618-6

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DOI： 10.1002/eji.201948342

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DOI： 10.1038/s41593-019-0532-y

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DOI： 10.1016/j.immuni.2019.05.009

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<jats:p>Traumatic spinal cord injury (SCI) brings numerous inflammatory cells, including macrophages, from the circulating blood to lesions, but pathophysiological impact resulting from spatiotemporal dynamics of macrophages is unknown. Here, we show that macrophages centripetally migrate toward the lesion epicenter after infiltrating into the wide range of spinal cord, depending on the gradient of chemoattractant C5a. However, macrophages lacking interferon regulatory factor 8 (IRF8) cannot migrate toward the epicenter and remain widely scattered in the injured cord with profound axonal loss and little remyelination, resulting in a poor functional outcome after SCI. Time-lapse imaging and P2X/YRs blockade revealed that macrophage migration via IRF8 was caused by purinergic receptors involved in the C5a-directed migration. Conversely, pharmacological promotion of IRF8 activation facilitated macrophage centripetal movement, thereby improving the SCI recovery. Our findings reveal the importance of macrophage centripetal migration via IRF8, providing a novel therapeutic target for central nervous system injury.</jats:p>

DOI： 10.1126/sciadv.aav5086

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DOI： 10.1002/glia.23570

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DOI： 10.1038/s41467-018-06224-y

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DOI： 10.1038/ncomms13102

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DOI： 10.1038/srep32461

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DOI： 10.1016/j.jphs.2015.08.002

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DOI： 10.1097/aln.0000000000000190

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Microglia, the resident immune cells of the central nervous system, are constitutively mobile cells that undergo rapid directional movement toward sites of tissue disruption. However, transcriptional regulatory mechanisms of microglial motility remain unknown. In the present study, we show that interferon regulatory factor-8 (IRF8) regulates microglial motility. We found that ATP and complement component, C5a, induced chemotaxis of IRF8 wild-type microglia. However, these responses were markedly suppressed in microglia lacking IRF8 (Irf8 (-/-)). In a consistent manner, phosphorylation of Akt (which plays a crucial role in ATP-induced chemotaxis) was abolished in Irf8 (-/-)microglia. Real-time polymerase chain reaction analysis revealed that motility-related microglial genes such as P2Y(12) receptor were significantly suppressed in Irf8 (-/-)microglia. Furthermore, Irf8 (-/-)microglia exhibited a differential expression pattern of nucleotide-degrading enzymes compared with their wild-type counterparts. Overall, our findings suggest that IRF8 may regulate microglial motility via the control of microglial gene expression.

DOI： 10.1007/s11302-014-9413-8

Language：English   Publishing type：Research paper (scientific journal)  

Microglia become activated by multiple types of damage in the nervous system and play essential roles in neuronal pathologies. However, how microglia transform into reactive phenotypes is poorly understood. Here, we identify the transcription factor interferon regulatory factor 8 (IRF8) as a critical regulator of reactive microglia. Within the spinal cord, IRF8 expression was normally low; however, the expression was markedly upregulated in microglia, but not in neurons or astrocytes, after peripheral nerve injury (PNI). IRF8 overexpression in cultured microglia promoted the transcription of genes associated with reactive states; conversely, IRF8 deficiency prevented these gene expressions in the spinal cord following PNI. Furthermore, IRF8-deficient mice were resistant to neuropathic pain, a common sequela of PNI, and transferring IRF8-overexpressing microglia spinally to normal mice produced pain. Therefore, IRF8 may activate a program of gene expression that transforms microglia into a reactive phenotype. Our findings provide a newly observed mechanism for microglial activation.

DOI： 10.1016/j.celrep.2012.02.014

Language：English   Publishing type：Research paper (scientific journal)  

Up-regulation of P2X4 receptors in spinal cord microglia is crucial for tactile allodynia, an untreatable pathological pain reaction occurring after peripheral nerve injury. How nerve injury in the periphery leads to this microglia reaction in the dorsal horn of the spinal cord is not yet understood. It is shown here that CCL21 was rapidly expressed in injured small-sized primary sensory neurons and transported to their central terminals in the dorsal horn. Intrathecal administration of a CCL21-blocking antibody diminished tactile allodynia development in wildtype animals. Mice deficient for CCL21 did not develop any signs of tactile allodynia and failed to up-regulate microglial P2X4 receptor expression. Microglia P2X4 expression was enhanced by CCL21 application in vitro and in vivo. A single intrathecal injection of CCL21 to nerve-injured CCL21-deficient mice induced long-lasting allodynia that was undistinguishable from the wild-type response. This effect of CCL21 injection was strictly dependent on P2X4 receptor function. Since neuronal CCL21 is the earliest yet identified factor in the cascade leading to tactile allodynia, these findings may lead to a preventive therapy in neuropathic pain. The EMBO Journal (2011) 30, 1864-1873. doi:10.1038/emboj.2011.89; Published online 25 March 2011

DOI： 10.1038/emboj.2011.89

Language：English   Publishing type：Research paper (scientific journal)  

IFN-gamma receptor signaling mediates spinal microglia activation driving neuropathic pain.

DOI： 10.1073/pnas.0810420106

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We have previously shown that activation of the ATP-gated ion channel subtype P2X(4) receptors (P2X(4)Rs) in the spinal cord, the expression of which is upregulated in microglia after nerve injury, is necessary for producing neuropathic pain. The upregulation of P2X(4)Rs in microglia is, therefore, a key process in neuropathic pain, but the mechanism remains unknown. Here, we find a fibronectin/integrin-dependent mechanism in the upregulation of P2X(4)Rs. Microglia cultured on dishes coated with fibronectin, an extracellular matrix molecule, expressed a higher level of P2X(4)R protein when compared with those cultured on control dishes. The increase was suppressed by echistatin, a peptide that selectively blocks beta(1) and beta(3)-containing integrins, and with a function-blocking antibody of beta(1) integrin. In in vivo studies, the upregulation of P2X(4)Rs in the spinal cord after spinal nerve injury was significantly suppressed by intrathecal administration of echistatin. Tactile allodynia in response to nerve injury and intrathecal administration of ATP- and fibronectin-stimulated microglia was inhibited by echistatin. Furthermore, intrathecal administration of fibronectin in normal rats increased the level of P2X(4)R protein in the spinal cord and produced tactile allodynia. Moreover, the fibronectin-induced allodynia was not observed in mice lacking P2X(4)R. Taken together with the results of our previous study showing an increase in the spinal fibronectin level after nerve injury, the present results suggest that the fibronectin/integrin system participates in the upregulation of P2X(4)R expression after nerve injury and subsequent neuropathic pain. (C) 2008 Wiley-Liss, Inc.

DOI： 10.1002/glia.20641

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Neuropathic pain, a debilitating chronic pain following nerve damage, is a reflection of the aberrant functioning of a pathologically altered nervous system. One hallmark is abnormal pain hypersensitivity to innocuous stimuli (tactile allodynia), for which effective therapy is lacking, and the underlying mechanisms of which remain to be determined. Here we show that Lyn, a member of the Src family kinases (SFKs), plays an important role in the pathogenesis of neuropathic pain. Nerve injury, but not peripheral inflammation, increased immunoreactivity for active SFKs that were autophosphorylated in the kinase domain (phospho-SFKIR) in spinal microglia. In spinally derived microglial cells, we identified Lyn as the predominant SFK among the five members (Src, Fyn, Yes, Lck, and Lyn) known to be expressed in the CNS. Lyn expression in the spinal cord was highly restricted to microglia, and its level was increased after nerve injury. We found that mice lacking lyn (lyn(-/-)) exhibit a striking reduction in the levels of phospho-SFK-IR and tactile allodynia after nerve injury, without any change in basal mechanical sensitivity or inflammatory pain. Importantly, lyn(-/-) mice displayed impaired upregulation of the ionotropic ATP receptor subtype P2X(4) receptors (P2X(4)R) in the spinal cord after nerve injury, which is crucial for tactile allodynia. Microglial cells from lyn(-/-) mice showed a deficit in their ability to increase P2X4R expression in response to fibronectin, a factor implicated as a microglial P2X4R upregulator in allodynia. Together, our findings suggest that Lyn may be a critical kinase mediating nerve injury-induced P2X4R upregulation and neuropathic pain. (c) 2007 Wiley-Liss, Inc.

DOI： 10.1002/glia.20591

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Peripheral tissue injury causes the release of various mediators from damaged and inflammatory cells, which in turn activates and sensitizes primary sensory neurons and thereby produces persistent pain. The present study investigated the role of platelet-activating factor (PAF), a phospholipid mediator, in pain signaling using mice lacking PAF receptor (pafr-/-mice). Here we show that pafr-/- mice displayed almost normal responses to thermal and mechanical stimuli but exhibit attenuated persistent pain behaviors resulting from tissue injury by locally injecting formalin at the periphery as well as capsaicin pain and visceral inflammatory pain without any alteration in cytoarchitectural or neurochemical properties in dorsal root ganglion (DRG) neurons and a defect in motor function. However, pafr-l- mice showed no alterations in spinal pain behaviors caused by intrathecally administering agonists for N- m ethyl- D-aspartate (NMDA) and neurokinin, receptors. A PAFR agonist evoked an intracellular Ca (2+) response predominantly in capsaicin-sensitive DRG neurons, an effect was not observed in pafr-l- mice. By contrast, the PAFR agonist did not affect C- or A delta-evoked excitatory postsynaptic currents in substantia gelatinosa neurons in the dorsal horn. Interestingly, mice lacking PAFR showed reduced phosphorylation of extracellular signal-related protein kinase (ERK), an important kinase for the sensitization of primary sensory neurons, in their DRG neurons after formalin injection. Furthermore, U0126, a specific inhibitor of the ERK pathway suppressed the persistent pain by formalin. Thus, PAFR may play an important role in both persistent pain and the sensitization of primary sensory neurons after tissue injury.

DOI： 10.1111/j.1471-4159.2007.04796.x

Responsible for pages：Vol.37 No.17, 単一細胞解析により明らかになったミクログリアの時空間的多様性   Language：Japanese   Book type：Scholarly book

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CiNii Books

Responsible for pages：Vol 7, Issue 9   Language：English   Book type：Scholarly book

DOI： https://doi.org/10.21769/BioProtoc.2252

Other Link： https://bio-protocol.org/e2252

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Language：English   Book type：Scholarly book

Event date： 2024.4

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：神戸   Country：Japan  

Repository Public URL： https://hdl.handle.net/2324/7174513

Event date： 2024.4

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Venue：上海   Country：China  

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Venue：Quebec city   Country：Canada  

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Venue：東京   Country：Japan  

Event date： 2024.4

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Venue：東京   Country：Japan  

Event date： 2024.4

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Venue：千葉   Country：Japan  

Event date： 2024.4

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Venue：横浜   Country：Japan  

Event date： 2024.4

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Venue：沖縄   Country：Japan  

Event date： 2023.5

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Venue：神戸   Country：Japan  

Event date： 2023.5

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Venue：横浜   Country：Japan  

Event date： 2022.9

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Venue：Karuizawa   Country：Japan  

Event date： 2022.7

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Venue：淡路島   Country：Japan  

Event date： 2022.6 - 2022.7

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Venue：沖縄   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：福岡国際会議場   Country：Japan  

Event date： 2022.1

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.1

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2022.1

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：奈良春日野国際フォーラム（奈良）   Country：Japan  

Event date： 2020.9

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：福岡   Country：Japan  

Event date： 2024.4

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2024.4

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2024.4

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2024.4

Language：English   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Event date： 2024.4

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：オンライン   Country：Japan  

Event date： 2024.4

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：長野   Country：Japan  

Event date： 2024.4

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：東京   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：大阪   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：北海道   Country：Japan  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋市立大学   Country：Japan  

Event date： 2022.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2012.7

Language：Japanese  

Venue：熊本   Country：Japan  

Event date： 2012.5 - 2012.6

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：Fukuoka   Country：Japan  

Event date： 2012.3

Language：English   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Following peripheral nerve injury (PNI), spinal microglia transform into reactive phenotypes and are implicated in producing neuropathic pain. However, the molecular mechanisms that regulate gene expression program in microglia remains to be elucidated. We have previously shown that interferon regulatory factor-8 (IRF8), a transcription factor that is upregulated in spinal microglia after PNI, plays a critical role in switching to reactive microglia. Here we identified IRF5 as a crucial mediator required for IRF8-dependent gene expression in reactive microglia. We found that forced expression of IRF8 in cultured microglia markedly increased expression of IRF5 in a manner that depended on its ability to bind DNA. Furthermore, mice lacking IRF8 failed to increase the expression of IRF5 in the spinal microglia after PNI, indicating IRF8-dependent expression of IRF5 in microglia in vivo. Interestingly, in IRF8-overexpressing microglial cells, knockdown of IRF5 expression resulted in suppressing IRF8-promoted transcription of genes associated with a reactive state of microglia. Altogether, the IRF8-IRF5 axis activates a program of gene expression that transforms microglia into reactive phenotypes crucial for neuropathic pain.

Event date： 2011.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡崎   Country：Japan  

神経障害などに伴った中枢性疾患発症時、ミクログリアはATP受容体や細胞内シグナル分子を過剰発現させ、炎症性サイトカインなどの生理活性液性因子を過剰産生・放出するなど、劇的にfunctional phenotype shiftを遂げ、「過活動」状態へと移行する。こうした過活動ミクログリアは、神経障害性疼痛発症においても重要な役割を果たしていることは明らかになっているが、ミクログリアの過活動状態への移行を司る遺伝子発現メカニズムは未だ明らかになっていない。本研究で、我々はInterferon regulatory factor-8(IRF8)がミクログリアの過活動状態への移行に重要な役割を果たしていることを見出した。
末梢神経損傷後、脊髄内でミクログリア特異的にIRF8の顕著な発現増加が観察された。一方、培養ミクログリア細胞にIRF8を強制発現させたところ、P2X4受容体やP2Y12受容体の顕著な発現増加が観察されるなど、過活動状態ミクログリアに見られる特徴的変化を示した。しかし、DNA結合能力の消失した変異型IRF8を遺伝子導入した際には、こうした変化は見られなかった。また、IRF8欠損マウスにおいては、野生型マウスと比較して、末梢神経損傷後に観察されるミクログリア関連分子(P2X4受容体やP2Y12受容体など)の発現増加および疼痛症状が有意に抑制された。以上の結果から、末梢神経損傷後に脊髄ミクログリアで発現増加したIRF8は、ミクログリアの過活動状態への移行に関与し、神経障害性疼痛発症に重要な役割を果たしていると考えられる。

Event date： 2011.9

Language：English   Presentation type：Oral presentation (general)  

Venue：石川   Country：Japan  

The interferon regulatory factor (IRF) family of transcription factors consists of nine members, which are expressed in peripheral immune cells and play important roles in gene expression and cellular development. Recent studies have shown that some members of the IRF family are also observed in the central nervous system (CNS). However, the functional relevance of IRFs in the CNS remains unknown. Microglia cells, the resident immune-related cells of the CNS, are crucial for sensing pathological alterations in the nervous system. As a consequence of injury to the nervous system, they transform to reactive states through a series of molecular changes including expression of various genes such as cell-surface receptors and proinflammatory cytokines, which are implicated in the pathogenesis of the CNS diseases such as neuropathic pain. However, the molecular mechanisms by which microglia switch to reactive phenotypes are poorly understood. Here we report that the IRF member IRF8 plays a crucial role in converting normal microglia into a reactive phenotype. Within the spinal cord, expression of IRF8 is normally low; however, expression was specifically upregulated in microglia after peripheral nerve injury (PNI). Forced IRF8 expression in cultured microglia promoted expression of genes associated with reactive phenotypes, depending on its ability to bind to DNA. IRF8 deficiency prevented the expression of these microglial genes in the spinal cord after PNI. We also found that mice lacking IRF8 exhibited resistance to PNI-induced pain hypersensitivity. Moreover, spinal transfer of IRF8-overexpressing microglia to normal mice produced pain hypersensitivity. Together, our present findings suggest IRF8 acts as a critical transcription factor involved in converting microglia to a reactive state that drives neuropathic pain.

Event date： 2011.9

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：プラハ   Country：Czech Republic  

Microglia are the CNS immune-related cells and associated with the pathogenesis of several types of neurological diseases. Following peripheral nerve injury (PNI), spinal microglia become hyperactive and have crucial roles in producing neuropathic pain. However, the key factor of microglia controlling their phenotype remains to be elucidated. Here, we found that interferon regulatory factor-8 (IRF8), a transcription factor, is specific to microglia in the spinal cord, whose expression is normally low, but markedly upregulated after PNI. Forced IRF8 expression in primary cultures of microglia with lentiviral vectors promoted transcription of various genes that enhance microglial activity or neuronal excitability. Intrathecal transferring of IRF8-expressing microglia to normal animals produced allodynic behavior (hypersensitivity to innocuous stimuli). These responses depend on its DNA binding domain. In a model of neuropathic pain, IRF8 deficiency prevented expression of microglial genes implicated in pain hypersensitivity and alleviated tactile allodynia without affecting proliferative activity of microglia. Together, IRF8 activates a program of nerve injury-dependent gene expression that converts microglia to be a hyperactive phenotype that gates neuropathic pain.

Event date： 2011.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡崎   Country：Japan  

神経損傷などに伴う中枢性疾患発症時、ミクログリアは細胞機能を司る受容体や細胞内シグナル分子を過剰発現させ、炎症性サイトカインなどの生理活性液性因子を過剰産生・放出するなど、劇的にfunctional phenotype shiftを遂げ、「過活動」状態になる。こうしたミクログリアは、神経障害性疼痛発症においても重要な役割を果たしていることは明らかになっているが、ミクログリアを過活動状態へと移行させる遺伝子発現メカニズムは未だ明らかになっていない。今回、我々はInterferon regulatory factor-8(IRF8)がミクログリアの過活動状態への移行に重要な役割を果たしていることを見出した。
末梢神経損傷後、脊髄内でミクログリア特異的にIRF8の発現増加が観察された。一方、レンチウィルスベクターを用いて培養ミクログリア細胞にIRF8を強制発現させたところ、機能分子の発現増加など、過活動状態ミクログリアに見られる特徴的変化を示した。しかし、DNA結合能力の消失した変異体IRF8を遺伝子導入した際には、こうした変化は見られなかった。また、IRF8欠損マウスにおいては、野生型マウスと比較して、神経損傷後のミクログリア関連分子の発現増加および疼痛症状が有意に抑制された。以上の結果から、末梢神経損傷後に脊髄ミクログリアで発現増加したIRF8は、ミクログリアの過活動状態への移行に関与し、神経障害性疼痛発症に重要な役割を果たしていると考えられる。

Event date： 2011.3

Language：English  

Country：Japan  

Event date： 2011.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2010.10

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：湘南   Country：Japan  

Neuropathic pain occurs after several diseases accompanied by nerve damage, which is characterized by abnormal sensory perception such as tactile allodynia (nocuous response to innocuous mechanical stimuli). This debilitating pain condition arises as a consequence of excessive excitability of neurons in the spinal dorsal horn, and the neuronal hyperexcitability involves signaling from activated spinal microglia that have induced or enhanced expression of various genes including proinflammatory cytokines. However, a key transcription factor regulating gene expression and neuropathic pain states is not identified. Here we report that interferon regulatory factor-8 (IRF-8), a member of IRF family transcription factor, controls gene expression in activated microglia responsible for tactile allodynia. Peripheral nerve injury (PNI) increased the expression of IRF-8 in spinal microglia in a cell type-specific manner. Furthermore, IRF-8-deficient mice (irf8-/-) exhibited a marked reduction in allodynia after PNI compared with wild-type mice without affecting normal pain sensitivity. In contrast, these mice showed a similar pain behavior in an inflammatory chronic pain model. Interestingly, irf8-/- mice failed to increase the expression of genes crucial for producing pain hypersensitivity in the spinal cord following PNI. Together, our present findings suggest that IRF-8 is the crucial intermediary for upregulating pain-related molecules and subsequent neuropathic pain.

Event date： 2010.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸   Country：Japan  

Neuropathic pain occurs after several diseases accompanied by nerve damage, which is characterized by abnormal sensory perception such as tactile allodynia (hypersensitivity to innocuous mechanical stimuli). This debilitating pain condition arises as a consequence of excessive excitability of neurons in spinal dorsal horn, and the neuronal hyperexcitability involves signaling from activated spinal microglia that induce or enhance expression of various genes including proinflammatory cytokines. However, a key transcription factor regulating gene expression and neuropathic pain states is not identified. In the present study, we examined the role of interferon regulatory factor-8 (IRF-8), a member of IRF family transcription factor, in regulating tactile allodynia. We found that peripheral nerve injury (PNI) increased the expression of IRF-8 in spinal microglia in a cell type-specific manner. Furthermore, mice lacking IRF-8 (irf8-/-) exhibited a marked reduction in allodynia after PNI compared with wild-type mice without affecting normal pain sensitivity or responses to cold stimuli. In contrast, these mice showed a similar pain behavior in an inflammatory chronic pain model. Interestingly, irf8-/- mice failed to increase the expression of genes crucial for producing pain hypersensitivity in the spinal cord following PNI. Together, our present findings suggest that IRF-8 critically contributes to the pathogenesis of neuropathic pain but not of inflammatory pain.

Event date： 2010.5 - 2010.6

Language：English   Presentation type：Oral presentation (general)  

Venue：タラゴナ   Country：Spain  

Neuropathic pain is a debilitating pain condition that arises as a consequence of excessive excitability of neurons in spinal dorsal horn after peripheral nerve injury (PNI). This pathological abnormality of neurotransmission involves signaling from activated spinal microglia that induce or enhance expression of various genes including purinoceptors and proinflammatory cytokines. However, a key transcription factor regulating gene expression and neuropathic pain states is not identified. In the present study, we examined the role of interferon regulatory factor-8 (IRF-8), a member of IRF family transcription factor, in regulating tactile allodynia (hypersensitivity to innocuous mechanical stimuli). We found that PNI increased the expression of IRF-8 in the spinal microglia in a cell-specific manner. Furthermore, mice lacking IRF-8 (irf8-/-) exhibited a marked reduction in allodynia after PNI compared with wild-type mice without affecting normal pain sensitivity or responses to cold stimuli. In contrast, these mice showed a similar pain behavior in an inflammatory pain model. Interestingly, irf8-/- mice failed to increase the expression of genes crucial for producing pain hypersensitivity (such as P2X7 and P2Y12) in the spinal cord following PNI. Together, our present findings suggest that IRF-8 critically contributes to the pathogenesis of neuropathic pain but not of inflammatory pain.

Event date： 2010.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Following peripheral nerve injury (PNI), spinal microglia become activated and are implicated in producing neuropathic pain. Activated microglia induce or enhance expression of various genes (such as proinflammatory cytokines), but a key transcriptional factor in spinal microglia that drives neuropathic pain is not identified. In the present study, we found that PNI increased the expression of interferon regulatory factor-8 (IRF-8), a transcription factor, in the spinal cord microglia. Furthermore, mice lacking IRF-8 exhibited a marked reduction in tactile allodynia (hypersensitivity to innocuous mechanical stimuli) after PNI compared to wild-type littermates without affecting basal pain sensitivity. Interestingly, these mice also failed to increase the expression of crucial factors for producing pain hypersensitivity in the spinal cord. Together, our present findings suggest that IRF-8 critically contributes to the pathogenesis of neuropathic pain after PNI.

Event date： 2009.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：福岡   Country：Japan  

Neuropathic pain is a debilitating pain condition that occurs after neuronal damage induced by diabetes, infection, or physical injury. A hallmark of this pain is abnormal sensory perception of pain such as allodynia (hypersensitivity to innocuous light stimuli). Accumulating evidence shows that spinal microglia exhibiting activated form (proliferation, hypertrophied soma) have a crucial role in producing allodynia after peripheral nerve injury. However, the mechanisms of microglia activation remain unknown. In the present study, we show that in naïve rat spinal microglia express the receptor for interferon-γ (IFN-γR) in a cell-type-specific fashion and that stimulating this receptor by intrathecal IFN-γ administration converts microglia into activated form and produces long-lasting allodynia. Furthermore, mice lacking IFN-γR failed to display nerve injury-induced microglia activation in the ipsilateral dorsal horn and allodynic behavior without affecting microglia in the contralateral side or basal pain sensitivity. We also found that stimulating IFN-γR up-regulates the expression of Lyn tyrosine kinase and purinergic P2X4 receptor in spinal microglia, crucial events for neuropathic pain. Using Lyn-deficient mice (lyn-/-) and P2X4-deficient mice (p2xr4-/-), we found that spinal IFN-γ injection-evoked microglia activation was impaired in lyn-/- mice, but not in p2xr4-/- mice. On the other hand, IFN-γ-induced allodynia was strongly attenuated both in lyn-/- and p2xr4-/- mice. Together, our present findings suggest that the IFN-γ/IFN-γR system contributes to nerve injury-induced microglia activation via Lyn tyrosine kinase, and tactile allodynia through Lyn tyrosine kinase and P2X4 receptor.

Event date： 2009.3

Language：English   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

After peripheral nerve injury, spinal microglia become activated form, which are critical for producing abnormal pain hypersensitivity, namely allodynia - a hallmark symptom of neuropathic pain. We have previously shown that in normal animals spinal microglia express interferon-γ (IFN-γ) receptors and that stimulating these receptors drive microglia to transform into activated ones and that mice lacking IFN-γ receptor exhibit impaired nerve injury-induced microglia activation and allodynia. However, the detailed mechanisms of IFN-γ-induced microglia activation remain unknown. In this study, we investigated the role of Lyn tyrosine kinase that is implicated in neuropathic pain. We found that intrathecal administration of IFN-γ upregulated the expression of Lyn in spinal microglia. In Lyn-deficient mice (lyn-/-), IFN-γ failed to activate microglia and to generate allodynic behavior. Furthermore, nerve injury-induced activation of microglia in the spinal dorsal horn was markedly suppressed in lyn-/- mice compared to wild-type mice. Together, our findings suggest that IFN-γ produces activation of microglia via Lyn kinase signaling, which in turn leads to allodynia after nerve injury.

Event date： 2008.11

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：ワシントン   Country：United States  

Neuropathic pain is a result of peripheral nerve injury in diabetes or cancer. A hallmark of this pain is abnormal sensory perception of pain such as allodynia (hypersensitivity to light stimuli). Spinal microglia exhibiting activated form (proliferation, hypertrophy of their cell bodies) have a crucial role in producing allodynia after nerve injury. We have previously shown that a single intrathecal administration of interferon-γ (IFN-γ) to normal animals produces progressive allodynia and spinal microglia activation and that mice lacking IFN-γ receptor display impaired nerve injury-induced microglia activation and allodynia. However, the detailed mechanisms of IFN-γ-dependent microglia activation remain unknown. In the present study, we examined the role of Lyn tyrosine kinase, upregulated in the spinal cord and involved in generating neuropathic allodynia after nerve injury. We found that intrathecal administration of IFN-γ upregulated the expression of Lyn in spinal microglia. In wild-type (WT) mice, intrathecal IFN-γ injection produced an increase in the number of microglia in the dorsal horn and allodynic behavior. In contrast, these changes were markedly suppressed in Lyn-deficient mice (lyn-/-). Furthermore, nerve injury-induced proliferation of microglia in the ipsilateral dorsal horn in WT mice was also attenuated in lyn-/- mice. Together, our findings suggest that IFN-γ produces the activation of microglia via Lyn kinase signaling, which in turn leads to allodynia after peripheral nerve injury.

Event date： 2008.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

癌や糖尿病などにより神経が損傷を受けることで、神経因性疼痛が発症する。この疼痛は、非侵害性刺激によって激烈な痛みを感じてしまうアロディニアが特徴的である。近年、我々は神経損傷後に脊髄内で活性化したミクログリアが神経因性疼痛発症に重要な役割を持つことを明らかにしてきた。しかし、これまでにミクログリア活性化の詳細なメカニズムは明らかになっていない。そこで本研究では、神経損傷後に脊髄内で発現増加することが報告されているインターフェロンγ（IFN-γ）に着目し、神経因性疼痛発症およびミクログリア活性化への関与について検討した。
IFN-γリコンビナントタンパク質を脊髄腔内投与することにより、強力かつ持続的なアロディニア症状を呈した。また、脊髄内でのIFN-γ受容体mRNA発現細胞はミクログリアのみであったことから、IFN-γ処置動物の脊髄におけるミクログリアを免疫染色法で観察した。その結果、ミクログリアは異常な活性化（増殖・細胞体の肥大化）を起こしていることが明らかになった。
続いて、IFN-γ受容体欠損マウスと用いて検討を行ったところ、野生型マウスに比べ、神経損傷後のアロディニア症状および損傷側脊髄後角でのミクログリア活性化に劇的な改善が観察された。
以上のことより、末梢神経損傷により脊髄内で発現増加するIFN-γは直接ミクログリアに作用し、その活性化を介して神経因性疼痛発症に重要な役割を持つことが明らかになった。

Event date： 2008.7

Language：English  

Venue：Fukuoka   Country：Japan  

Neuropathic pain is a result of peripheral nerve injury in diabetes or cancer. A hallmark of this pain is abnormal sensory perception of pain such as allodynia (hypersensitivity to light stimuli). We have previously shown that spinal microglia exhibiting activated form have a crucial role in producing allodynia after nerve injury. However, the mechanisms of microglia activation remain unknown. In the present study, we examined the role of interferon-γ (IFN-γ), reported to be upregulated in the spinal cord of animal models of neuropathic pain, in microglial activation and neuropathic allodynia. We found that intrathecal administration of IFN-γ produced long-lasting allodynia. The expression of IFN-γ receptor mRNA in the spinal cord of naïve rats was present only in microglia. In the dorsal horn of IFN-γ-treated rats, microglia dramatically changed their morphology into hypertrophy and also proliferated, both of which are prominent features of activated microglia. We next examined the role of IFN-γ in tactile allodynia and microglia activation after peripheral nerve injury using mice lacking IFN-γ receptor (ifngr-/-). We found that ifngr-/- mice exhibited a marked reduction in tactile allodynia after nerve injury compared with wild-type (WT) mice. Furthermore, in WT mice, nerve injury increased the number of microglial cells with hypertrophic morphology in the ipsilateral dorsal horn. In contrast, these changes were markedly suppressed in ifngr-/- mice. Together, our present findings suggest that the IFN-γ/IFN-γ receptor system has crucial roles in activating microglia and producing tactile allodynia after nerve injury.

Event date： 2008.6 - 2008.7

Language：English   Presentation type：Symposium, workshop panel (public)  

Venue：コペンハーゲン   Country：Denmark  

Interferon-γ signals were required in spinal microglia activation and neuropathic pain after peripheral nerve injury

Language：Japanese  

Language：English  

Language：English  

Language：English  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：English  

Language：English  

Language：English  

Language：Japanese  

Language：English  

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Language：Japanese  

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Authorship：Lead author   Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.1016/j.celrep.2020.01.010.

Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： 10.1038/s41583-019-0201-x

Language：English   Publisher：(一社)日本神経免疫学会  

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publisher：(株)羊土社  

脳や脊髄を含む中枢神経系は,全身機能を統括する重要組織であることは疑いようもないが,そのきわめて高度な機能の獲得や維持において欠かすことのできないのが本稿で取りあげるミクログリアである.脳内マクロファージの一種であるミクログリアは,死細胞の除去や組織炎症の制御など典型的な免疫機能のみならず,ほぼすべての脳内生理現象にかかわると考えられている.本稿では,ミクログリアの細胞特性や機能,特に中枢神経系疾患における役割やその機能的多様性について最新の知見を交えながら概説する.(著者抄録)

Authorship：Last author,　Corresponding author   Language：Japanese   Publisher：(株)ニュー・サイエンス社  

脳には,神経細胞の他にも免疫系の細胞であるミクログリアが存在し,脳の機能を支えている。成体脳におけるミクログリアの機能解明が進んできた一方,近年,胎生期や生後の脳においてもさまざまな役割を担うことが明らかになりつつある。ミクログリアは,ニューロンや他のグリア細胞とは起源が異なり,卵黄嚢から生じることが知られる。しかし,ミクログリアがいかにして脳に定着するかに関して,その詳細は不明である。最近筆者らは,マウスにおいて脳内のミクログリアは少なくとも二つの異なる定着ルートをたどる細胞集団からなることを見出した。胎生早期にミクログリアの性質を備えて脳に定着を開始する群に加えて,その後遅れて脳室から流入する群が存在することが分かった。本稿では,ミクログリアの脳定着プロセスの解明が性質・機能多様性の理解にどう役立つのかという点にフォーカスし,最新の研究を紹介しながら解説する。(著者抄録)

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)   Publisher：(有)科学評論社  

アストロサイトやオリゴデンドロサイトとともにグリア細胞に分類されるミクログリアは、脳内主要免疫細胞としても知られる脳内マクロファージであり、最近では「神経シナプスの剪定」や「髄鞘形成の促進」といった"免疫"の域にとどまらない機能が数多く報告されている。今回、ミクログリアの発生維持メカニズムや細胞特性、細胞機能、中枢神経疾患への関与などについて、これまでの知見を以下の項目に分けて概説した。1)ミクログリアの発生と脳内定着・維持。2)ミクログリアと脳境界マクロファージ。3)ミクログリアのアルツハイマー病への関与。4)多発性硬化症への関与。5)腸内細菌叢によるミクログリア機能の制御。

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publisher：(一社)日本神経化学会  

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)   Publisher：鳥居薬品(株)  

脳と脊髄で構成される中枢神経系が全身機能を司る重要組織であることは周知の事実であるが,その組織環境や機能を維持するために欠かすことのできない存在として知られるのが中枢神経系マクロファージである.中枢神経系マクロファージは,分布領域の違いから,実質内に存在するミクログリアと,髄膜や血管周囲スペースなどの境界領域に存在する脳境界マクロファージに大別される.ミクログリアは死細胞の除去やシナプス剪定などさまざまな機能を担うことが明らかになっている一方で,脳境界マクロファージの存在意義や細胞特性にはいまだ不明な点が多く,またミクログリアと脳境界マクロファージを正確に分けて解析した報告も少ない.そのようななか,近年の研究技術の進歩や研究ツールの開発に伴って,両細胞種の分離機能解析が可能になってきた.本稿では,ミクログリアと脳境界マクロファージの細胞特性や機能に関して,最新の知見を交えて概説する.(著者抄録)

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：(公社)日本薬理学会  

脳および脊髄を含む中枢神経系組織は,神経細胞やグリア細胞,血管系細胞や免疫細胞など多種多様な細胞によって構成され,それらの複雑かつダイナミックな相互作用によって高度な機能が維持されている.その中でも,中枢機能を正確に維持するために欠かすことのできない細胞が,著者らの研究対象である脳内マクロファージである.脳内マクロファージと聞いてまず思い浮かぶのが,脳内主要免疫細胞として知られるミクログリアではないかと思う.長年の研究から,ミクログリアの細胞特性や機能,他の免疫細胞との関係,中枢神経系疾患への関与などが明らかになってきている.一方,ミクログリアの傍らであまり目を向けられてこなかった第2の脳内マクロファージが存在する.それが,髄膜や血管周囲空間などの境界領域に存在する脳境界マクロファージ(CNS associated macrophages:CAMs)である.その存在は長年認知されてきたものの,CAMsはミクログリアと遺伝子プロファイルが非常に似ており,これまで両細胞種を正確に分けて解析した報告は少なかった.近年,CAMsに着目した研究も増加しつつあり,その理解もようやく進み始めた.本稿では,ミクログリアおよびCAMsに関して,その発生・維持メカニズムや細胞特性,またそれらを解析するための研究ツールについて,最新の知見を交えて概説する.(著者抄録)

Language：English   Publisher：(一社)日本炎症・再生医学会  

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)   Publisher：(株)癌と化学療法社  

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Authorship：Lead author,　Last author,　Corresponding author   Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：(公社)日本生化学会  

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脳や脊髄を含む中枢神経系は,無数に張り巡らされた神経細胞を基本骨格とした複雑な構造体である.その間質領域は,免疫細胞やグリア細胞,血管系細胞など多様な細胞によって満たされているが,それらは単なる組織の支持細胞ではなく,複雑かつダイナミックな相互作用を介して中枢神経系の高度な機能発現に積極的に関与している.本稿では,中枢神経系の間質における主要免疫細胞として知られる脳内マクロファージのうち,とくにミクログリアの細胞特性や疾患発症への関与について,最新の知見を交えて概説する.(著者抄録)

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)   Publisher：(株)アークメディア  

Authorship：Lead author,　Last author,　Corresponding author   Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

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中枢神経系を構成する主要免疫細胞として君臨するミクログリアの傍らで,あまり目を向けられてこなかった第2の脳内マクロファージが存在する.それが,脳境界マクロファージ(CNS associated macrophages, CAMs)である.その存在は数十年前から認知されていたにもかかわらず,これまでミクログリアとCAMsを正確に分けて解析した報告は少ない.しかし,近年の研究技術の進歩に伴って,CAMsに着目した研究も増加しつつあり,その理解も進み始めた.本稿では,これまで明らかになっているCAMsの細胞特性や機能に関して,特にミクログリアとの類似・相違点という観点から概説する.(著者抄録)

Language：English   Publisher：Nature  

In the version of this article initially published online, there was a copy– paste duplication of values in the source data for Figure 1b, Parenchyma: Cx3cr1-GFP+. The correct values have been restored in the HTML version of this article.

DOI： 10.1038/s41586-022-05361-1

Scopus

PubMed

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Nature Neuroscience  

In the version of this article initially published, Fig.3b,c, Fig. 5a–d, Extended Data Fig. 1 and Supplementary Fig. 8b contained errors. Fig. 3b and c showed incorrect immunohistochemistry quantifications. Fig. 5a contained a duplicate image for the TMEM119 control sample, and panels b and c showed incorrect immunohistochemistry quantifications. Fig. 5d contained an incorrect image for the t-SNE map of P2RY12; it was a duplicate of the map for HLA-DRA. Extended Data Fig. 1 contained incorrect images in panel a for Pat 7 (TMEM119), Pat 12 (TMEM119, CD74) and Pat 15 (CD68) and in panel b for Pat 3 (GFAP), Pat 12 (TMEM119 and P2YR12) and Pat 13 (TMEM119). Supplementary Fig. 8b contained an incorrect image for the CSF2 t-SNE panel. In addition, the legend for Fig. 5b as well as the description of Fig. 1b in Methods incorrectly said that the test used was a paired t-test; it should read ‘unpaired t-test’ in both places. In the Results section, the sentence “Normalization for the number of IBA1+ cells revealed lower expression of the bona fide microglial markers P2RY12 and TMEM119, and higher expression of HLA-DR (Fig. 5c)” should read “no change of expression” instead of “lower expression”. The errors have been corrected in the HTML and PDF versions of the article.

DOI： 10.1038/s41593-022-01089-3

Scopus

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： DOI: 10.11481/topics107

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

DOI： DOI: 10.1021/acschemneuro.5b00317

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Neuropathic pain, a debilitating pain condition, is a common consequence of damage to the nervous system. Neuropathic pain is often resistant to currently available analgesics. A growing body of evidence indicates that spinal microglia react and undergo a series of changes that directly influence the establishment of neuropathic pain states. After nerve injury, P2X4 receptors (P2X4Rs) are upregulated in spinal microglia by several factors at the transcriptional and translational levels. Those include the CC chemokine CCL21 derived from damaged neurons, the extracellular matrix protein fibronectin in the spinal cord, and the transcription factor interferon regulatory factor 8 (IRF8) expressed in microglia. P2X4R expression in microglia is also regulated at the post-translational level by signaling from other cell-surface receptors such as CC chemokine receptor (CCR2). Importantly, inhibiting the function or expression of P2X4Rs and P2X4R-regulating molecules suppresses the aberrant excitability of dorsal horn neurons and neuropathic pain. These findings indicate that P2X4R-positive microglia are a central player in mechanisms for neuropathic pain. Thus, microglial P2X4Rs are a potential target for treating the chronic pain state.

Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Neuropathic pain is a highly debilitating chronic pain state that is a consequence of nerve injury or of diseases such as diabetes, cancer, infection, autoimmune disease, or trauma. Neuropathic pain is often resistant to currently available analgesics. There is a rapidly growing body of evidence indicating that signalings from spinal microglia play crucial roles in the pathogenesis of neuropathic pain. After peripheral nerve injury, microglia transform to reactive states through the expression of various genes such as cell-surface receptors (including purinergic receptors) and proinflammatory cytokines that enhance synaptic transmission in dorsal horn neurons. Inhibiting function or expression of these microglial molecules strongly suppresses pain hypersensitivity to innocuous mechanical stimuli (tactile allodynia), a hallmark symptom of neuropathic pain. A recent study also reveals that the transcription factor IRF8 (interferon regulatory factor 8) is a critical regulator of the nerve injury-induced gene expression in microglia. The present review article highlights the recent advances in our understanding of spinal microglia in neuropathic pain.