| 1. |
Irie T, Matsuda T, Hayashi Y, Matsuda-Ito K, Kamiya A, Masuda T, Prinz M, Isobe N, Kira JI, Nakashima K, Direct neuronal conversion of microglia/macrophages reinstates neurological function after stroke., PNAS, 120(42), 2023.10. |
| 2. |
Travis E Faust, Philip A Feinberg, Ciara O'Connor, Riki Kawaguchi, Andrew Chan, Hayley Strasburger, Maximilian Frosch, Margaret A Boyle, Takahiro Masuda, Lukas Amann, Klaus-Peter Knobeloch, Marco Prinz, Anne Schaefer, Dorothy P Schafer, A comparative analysis of microglial inducible Cre lines, Cell Reports, 10.1016/j.celrep.2023.113031, 42(9):113031, 2023.08. |
| 3. |
Masuda T, Amann L, Monaco G, Sankowski R, Staszewski O, Krueger M, Del Gaudio F, He L, Paterson N, Nent E, Fernández-Klett F, Yamasaki A, Frosch M, Fliegauf M, Bosch LFP, Ulupinar H, Hagemeyer N, Schreiner D, Dorrier C, Tsuda M, Grothe C, Joutel A, Daneman R, Betsholtz C, Lendahl U, Knobeloch KP, Lämmermann T, Priller J, Kierdorf K, Prinz M, Specification of CNS macrophage subsets occurs postnatally in defined niches, Nature, 10.1038/s41586-022-04596-2, 604, 7907, 740-748, 2022.04. |
| 4. |
Kohno K, Shirasaka R, Yoshihara K, Mikuriya S, Tanaka K, Takanami K, Inoue K, Sakamoto H, Ohkawa Y, Masuda T, Tsuda M, A spinal microglia population involved in remitting and relapsing neuropathic pain, Science, 10.1126/science.abf6805, 376, 6588, 86-90, 376(6588):86-90, 2022.04. |
| 5. |
Bosch-Queralt M, Cantuti-Castelvetri L, Damkou A, Schifferer M, Schlepckow K, Alexopoulos I, Lütjohann D, Klose C, Vaculčiaková L, Masuda T, Prinz M, Monroe KM, Di Paolo G, Lewcock JW, Haass C, Simons M, Diet-dependent regulation of TGFβ impairs reparative innate immune responses after demyelination, Nature Metabolism, 2021.02. |
| 6. |
Wieghofer P, Hagemeyer N, Sankowski R, Schlecht A, Staszewski O, Amann L, Gruber M, Koch J, Hausmann A, Zhang P, Boneva S, Masuda T, Hilgendorf I, Goldmann T, Boettcher C, Priller J, Rossi FMV, Lange C, Prinz M, Mapping the origin and fate of myeloid cells in distinct compartments of the eye by single-cell profiling, EMBO JOURNAL, 10.15252/embj.2020105123, 40, 6, 2021.03. |
| 7. |
Takahiro Masuda, Profiling peripheral nerve macrophages reveals two macrophage subsets with distinct localization, transcriptome and response to injury, Nature Neuroscience, 10.1038/s41593-020-0618-6, 23(5):676-689, 2020.05. |
| 8. |
Takahiro Masuda, Comparative analysis of CreER transgenic mice for the study of brain macrophages: A case study, European Journal of Immunology, 10.1002/eji.201948342, 50(3):353-362, 2020.03. |
| 9. |
Takahiro Masuda, A Subset of Skin Macrophages Contributes to the Surveillance and Regeneration of Local Nerves, Immunity, 10.1016/j.immuni.2019.05.009, 50(6):1482-1497, 2019.06. |
| 10. |
Takahiro Masuda, Macrophage centripetal migration drives spontaneous healing process after spinal cord injury, Science Advances, 10.1126/sciadv.aav5086, 5 (5): eaav5086, 2019.05, 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. . |
| 11. |
Tozaki-Saitoh H, Masuda J, Kawada R, Kojima C, Yoneda S, Masuda T, Inoue K, Tsuda M, Transcription factor MafB contributes to the activation of spinal microglia underlying neuropathic pain development., Glia, 10.1002/glia.23570, 67, 4, 729-740, 67(4):729-740, 2018.11. |
| 12. |
Takahiro Masuda, Glucocorticoid regulation of ATP release from spinal astrocytes underlies diurnal exacerbation of neuropathic mechanical allodynia, Nature Communications, 10.1038/ncomms13102, 7, 2016.12. |
| 13. |
Tsuda M, Tozaki-Saitoh H, Masuda T, Toyomitsu E, Tezuka T, Yamamoto T, Inoue K, Lyn tyrosine kinase is required for P2X(4) receptor upregulation and neuropathic pain after peripheral nerve injury., Glia, 10.1002/glia.20591, 56, 1, 50-58, 2008.01, 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.. |
| 14. |
Tsuda M, Toyomitsu E, Komatsu T, Masuda T, Kunifusa E, Nasu-Tada K, Koizumi S, Yamamoto K, Ando J, Inoue K, Fibronectin/integrin system is involved in P2X(4) receptor upregulation in the spinal cord and neuropathic pain after nerve injury., Glia, 10.1002/glia.20641, 56, 5, 579-585, 2008.04, 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.. |
| 15. |
Makoto Tsuda, Takahiro Masuda, Junko Kitano, Hiroshi Shimoyama, Hidetoshi Tozaki-Saitoh, Kazuhide Inoue, These authors contributed equally to this work, IFN-γ receptor signaling mediates spinal microglia activation driving neuropathic pain., Proceedings of the National Academy of Sciences of the United States of America (PNAS), 10.1073/pnas.0810420106, 106, 19, 8032-8037, 2009.04. |
| 16. |
Biber K, Tsuda M, Tozaki-Saitoh H, Tsukamoto K, Toyomitsu E, Masuda T, Boddeke H, Inoue K, Neuronal CCL21 up-regulates microglia P2X4 expression and initiates neuropathic pain development., The EMBO journal, 10.1038/emboj.2011.89, 30, 9, 1864-1873, 2011.03, 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. |
| 17. |
Masuda T, Tsuda M, Yoshinaga R, Tozaki-Saitoh H, Ozato K, Tamura T, Inoue K, IRF8 is a critical transcription factor for transforming microglia into a reactive phenotype., Cell reports, 10.1016/j.celrep.2012.02.014, 1, 4, 334-340, 2012.04, 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.. |
| 18. |
Masuda T, Nishimoto N, Tomiyama D, Matsuda T, Tozaki-Saitoh H, Tamura T, Kohsaka S, Tsuda M, Inoue K, IRF8 is a transcriptional determinant for microglial motility., Purinergic signalling, 10.1007/s11302-014-9413-8, 10, 3, 515-521, 2014.05, 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.. |
| 19. |
Masuda T, Iwamoto S, Yoshinaga R, Tozaki-Saitoh H, Nishiyama A, Mak TW, Tamura T, Tsuda M, Inoue K, Transcription factor IRF5 drives P2X4R+-reactive microglia gating neuropathic pain., Nature communications, 10.1038/ncomms4771, 5, 2014.05. |
| 20. |
Makoto Tsuda, Satoshi Ishii, Takahiro Masuda, Shigeo Hasegawa, Koji Nakamura, Kenichiro Nagata, Tomohiro Yamashita, Hidemasa Furue, Hidetoshi Tozaki-Saitoh, Megumu Yoshimura, Schuichi Koizumi, Takao Shimizu, Kazuhide Inoue, Reduced pain behaviors and extracellular signal-related protein kinase activation in primary sensory neurons by peripheral tissue injury in mice lacking platelet-activating factor receptor, JOURNAL OF NEUROCHEMISTRY, 10.1111/j.1471-4159.2007.04796.x, 102, 5, 1658-1668, 2007.09, 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.. |
