一般演題（口述）

一般演題（口述） Pain・Ischemia

2O2-01 Regulation of post-ischemic inflammation by DAMPs Shichita Takashi^1,2，Ito Minako¹，Yoshimura Akihiko¹ ¹Department of Microbiology and Immunology, School of Medicine, Keio University，²Precursory Research for Embryonic Science and Technology（PRESTO）, Japan Science and Technology Agency Inflammation is an essential step for the pathology of ischemic stroke. Because brain is a sterile organ, the inflammation is triggered by some endogenous molecules. High mobility group box 1（HMGB1）is the well-known danger associated molecular patterns（DAMPs）which exaggerate the disruption of blood brain barrier. Here, we have identified peroxiredoxin（Prx）family proteins as previously unknown DAMPs in the ischemic brain. Prx activates infiltrating immune cells and induces the inflammatory cytokine production through TLR2 and TLR4 signaling pathway. Both the extracellular release of Prx and the infiltration of immune cells reach the peak within 1 to 3 days after the onset of ischemic stroke and thereafter they decrease. This will lead to the resolution of post-ischemic inflammation. Indeed, the gene expression profile of infiltrating immune cells in the late phase shows the phenotype for anti-inflammation and tissue repair. Our results indicate that macrophage and microglia contribute to the resolution of post-ischemic inflammation independently. DAMPs regulate not only the induction but also the resolution of post-ischemic inflammation. The novel neuroprotective strategy for ischemic stroke will be developed by promoting the resolution of post-ischemic inflammation.		2O2-02 Prothymosin-alpha implicates microglial TLR4 for the prevention of ischemic damages in retina HALDER SEBOK_K，UEDA HIROSHI Department of Pharmacology and Therapeutic Innovation, Nagasaki University Graduate School of Biomedical Sciences Toll-like receptor（TLR4）is one of the well-discussed components in neurobiology owing to its dual roles, harmful and beneficial, in ischemia. TLR4 generally contributes to ischemic damages in the central nervous system including brain and retina, whereas the ischemic- or lipopolysaccharide-preconditioning provides TLR4-mediated neuroprotection against severe ischemia. Prothymosin-alpha, a nuclear protein, is implicated in multiple functions including the protection of brain and retina from ischemic damages. Although prothymosin-alpha contributes to TLR4-mediated immunopotentiation against virus, the beneficial effects of prothymosin-alpha-TLR4 signaling against ischemia remain to be elucidated. In the present study, preconditioning treatment with prothymosin-alpha 48 h before retinal ischemia prevented the cellular damages estimated by histology and immunohistochemical analyses, and functional deficits of retina evaluated by electroretinography. Prothymosin-alpha preconditioning prevented the ischemia-induced loss of ganglion, bipolar and photoreceptor cells, but not amacrine cells. Prothymosin-alpha treatment in the absence of ischemia caused the mild activation, proliferation and migration of retinal microglia, whereas the ischemia-induced microglia activation was inhibited by prothymosin-alpha preconditioning. All of these preventive actions by prothymosin-alpha preconditioning against ischemia were abolished in TLR4 knock-out mice, and by pretreatments with anti-TLR4 antibodies or minocycline, a microglial inhibitor, which themselves had no effects on the ischemia-induced damages or microglia activation. Taken together, the present study suggested that TLR4 mediates prothymosin-alpha preconditioning-induced prevention through microglia in the retinal ischemia model.

2O2-03 Essential role for STAT3-dependent reactive astrocytes in maintenance of chronic itch Shiratori-Hayashi Miho¹，Koga Keisuke^1,2，Tozaki-Saitoh Hidetoshi^1,2，Kohro Yuta²，Hachisuka Junichi³，Okano Hideyuki⁴，Furue Masutaka³，Inoue Kazuhide²，Tsuda Makoto^1,2 ¹Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University，²Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University，³Department of Dermatology, Graduate School of Medicine, Kyushu University，⁴Department of Physiology, Keio University School of Medicine Chronic itch is a debilitating symptom of skin diseases, such as atopic and contact dermatitis. Recent studies have revealed neuronal pathways selective for itch, but the mechanisms by which itch turns into a pathological chronic state are poorly understood. Using mouse models of atopic and contact dermatitis, we demonstrate a long-term reactive state of astrocytes in the dorsal horn of the spinal segments corresponding to the lesioned, itchy skin. We further found that STAT3 was selectively activated in dorsal horn astrocytes and that conditional disruption of astrocytic STAT3 activation prevented reactive astrocytes and chronic itch without affecting acute physiological itch. Pharmacological inhibition of spinal STAT3 alleviated fully developed chronic itch. Moreover, atopic dermatitis mice exhibited a striking enhancement of scratching evoked by intrathecal GRP, an itch-inducing neuropeptide, and this phenotype was normalized by suppressing astrocytic STAT3. Our findings indicate that STAT3-mediated reactive astrocytes in the spinal dorsal horn are necessary for the maintenance for chronic itch by inducing spinal sensitization of itch, providing a previously unrecognized target for treating chronic itch.		2O2-04 Translational research of chronic pain patients using human blood-induced microglia-like（iMG）cells Ohgidani Masahiro¹，Kato Takahiro^1,2，Hosoi Masako³，Tsuda Makoto⁴，Hayakawa Kohei¹，Sudo Nobuyuki³，Kanba Shigenobu¹ ¹Dept. of Neuropsychiatry, Kyushu Univ.，²Innovation Center for Medical Redox Navigation, Kyushu Univ.，³Dept. of Psychosomatic Medicine, Kyushu Univ.，⁴Dept. of Life Innovation, Kyushu Univ. Backgrounds： Chronic pain is known to be one of the most intractable diseases with frequent and various physical symptoms. Unremitting pain restricts activities of daily live, and these situations tend to affect psychosocial conditions, and may easily induce various psychiatric conditions such as depression and anxiety. The underlying biological mechanisms of chronic pain have not been well clarified, while recent rodent studies using the models of chronic pain have suggested the abnormalities of microglia, immune cells in the CNS. Dynamic actions of microglia in living humans have not been clarified due to a lack of studies dealing with in situ microglia. Recently, we developed a novel technique to induce microglia-like（iMG）cells from human peripheral blood（Ohgidani et al. Sci Rep 2014）. Methods： Herein, we compared the responses of iMG cells against external stimuli between healthy controls（HC：n=10）and chronic pain patients（CPP：n=14）. Results： Basal mRNA expression level of TNF-α was significantly lower in CPP-iMG cells compared to HC-iMG cells. Interestingly, TNF-α expression after ATP stimulus was significantly higher in CPP-iMG cells compared to HC-iMG cells. Discussion： These data have suggested that microglial response against external stimulus could be supersensitive in CPP compared to HC. TNF-α from microglia may be a key player in the pathophysiology of chronic pain.