栄養因子、サイトカイン Trophic Factors and Cytokines
P3-1-65 グルココルチコイドが抑制する栄養因子依存的シナプス機能へのshp2の関与 Possible involvement of shp2 in an influence of glucocorticoid on neurotrophin-dependent synapse regulation ○沼川忠広1,2, 安達直樹1,2, 熊丸絵美1, 大島淑子1, 功刀浩1,2 ○Tadahiro Numakawa1,2, Naoki Adachi1,2, Emi Kumamaru1, Yoshiko Ooshima1, Hiroshi Kunugi1,2 国立精神・神経医療研究センター　神経研究所　疾病研究第三部1, 戦略的創造研究推進事業、科学技術振興機構2 Department of Mental Disorder Research, National Institute of Neuroscience, NCNP, Tokyo, Japan1, CREST, JST, Saitama, Japan2 Glucocorticoids, one of steroids, are suggested to be involved in the pathophysiology of mental disorders. In addition, downregulation of brain-derived neurotrophic factor which has critical roles in neuronal functions in the central nervous system is also implicated in the onset of mental disorders including depression. Recently, we found that long-lasting exposure with glucocorticoid disturbed an increase of synapse in the presence of BDNF in cultured neurons (FEBS Letters 2011). In the BDNF-mediated synaptic maturation, long-lasting duration of ERK signaling stimulated by BDNF is essential, however, glucocorticoid decreased the ERK activation. In our system, we observed that an interaction between Shp2, one of phosphatase, with TrkB (a receptor for BDNF) was suppressed by glucocorticoid. Furthermore, Shp2 inhibitor mimicked the glucocorticoid action, implying an involvement of decreased Shp2-TrkB interaction in the negative effect of glucocorticoid.	P3-1-66 前駆体BDNFは p75NTRの活性化を介してスパイン形態を変える ProBDNF affects dendritic spine morphology and reorganizes the actin cytoskeleton through activation of p75NTR ○水井利幸1,2, 熊ノ郷晴子1,2, 清末和之1,2, 小島正己1,2 ○Toshiyuki Mizui1,2, Haruko Kumanogoh1,2, Kazuyuki Kiyosue1,2, Masami Kojima1,2 （独）産業技術総合研究所　健康工学研究部門　バイオインターフェース研究グループ1 AIST, Osaka, Japan1, CREST, JST, Japan2 Dendritic spines are the major structures of excitatory synaptic input, and their morphological changes are hypothesized to closely link to learning and memory. However, the underlying mechanism is not fully understood. Brain-derived neurotrophic factor (BDNF), through the activation of tropomyosin-related kinase B (TrkB), elicits synaptic transmission and modulates some forms of synaptic plasticity, such as long-term potentiation (LTP) and depression (LTD). We recently showed that the precursor form of BDNF (proBDNF) affected dendritic spines through a pan-neurotrophin receptor p75NTR and decreased the amplitude of synaptic transmission. In the present study, we analyzed the effect of proBDNF on the morphology of dendritic spines in Banker-style low-density culture of hippocampal neurons. At 21 days in vitro, the cultured neurons expressing green fluorescent protein (GFP) were treated with proBDNF for 48 hours and the morphology of dendritic spines was quantitated. Remarkably, proBDNF significantly decreased the width and increased the length of dendritic spines. Nevertheless, there were no significant differences on cell viability, total dendritic protrusion density and the density of synapsin I antibody-labeled pre-synaptic terminals. Furthermore, proBDNF significantly reduced the intensity of rhodamine-conjugated phalloidin in the dendritic spines. Importantly, the depletion of p75NTR activity inhibited the proBDNF-induced spine shrinkage and reduction of F-actin in the spines. Together, we conclude that proBDNF induces the shrinkage of the dendritic spines and reorganization of actin cytoskeleton in the dendritic spines through activation of p75NTR.
P3-1-67 グルココルチコイドがBDNFの神経細胞内輸送に及ぼす影響 Glucocorticoids affect the intracellular transport of BDNF in cortical neurons ○安達直樹1,2, 沼川忠広1,2, 大島淑子1, 功刀浩1,2 ○Naoki Adachi1,2, Tadahiro Numakawa1,2, Yoshiko Ooshima1, Hiroshi Kunugi1,2 （独）国立精神・神経医療研究セ　神経研　疾病三部1, 戦略的創造研究推進事業2 Dept Mental Disorder Research, Institute of Neuroscience, NCNP, Tokyo1, CREST, JST, Saitam, Japan2 Dysregulation of circulating glucocorticoids levels has been implicated in the onset of major depression. Brain-derived neurotrophic factor (BDNF) plays many important roles in the regulation of neuronal function and is also suggested to be involved in the pathophysiology of several psychiatric diseases. We have been reported adverse effects of chronic glucocorticoids treatment on the BDNF-dependent signaling pathways in cortical neurons. In this study, we examined glucocorticoid's effects on intracellular behavior of BDNF such as dendritic/axonal transport or secretion. We found that a synthetic glucocorticoid dexamethasone (DEX) affected BDNF transport in cultured cortical neurons. We are investigating the molecular mechanisms underlying the modulation of BDNF transport by glucocorticoids. Acknowledgements: This work is supported by a grant from the Naito Foundation (N. A.), and Grant-in-Aid for Scientific Research (B) (24300139) (T. N.) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.	P3-1-68 BDNF pro-peptideは海馬LTPの新規の促進系であり、その生物学的機能はBDNFの一塩基多型で異なる The BDNF pro-peptide is a novel facilitator of hippocampal LTD and the biological action is modulated by a common BDNF polymorphism Val66Met ○小島正己1,3, 上垣浩一1,3, 石川保幸1,2,3, 水井利幸1,3, 延原理幹1,3,7, 小塚孝司1,7 ○Masami Kojima1,3, Koichi Uegaki1,3, Yasuyuki Ishikawa1,2,3, Toshiyuki Mizui1,3, Michimasa Nobuhara1,3,7, Takashi Kozuka1,7 産総研・健康工学研究部門・バイオインターフェース研究グループ1, 奈良先端大・バイオサイエンス・神経機能2, 科学技術振興機構　戦略的創造研究推進事業3, 北里大・医・生化学4, 埼玉医大・医・生理5, 産総研・バイオメディシナル情報研究センター6, 関西大学・化学生命工学部・ 生命生物工学科7 Bio-interface Research Group, Health Research Inst., National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Japan1, Laboratory of Functional Neuroscience, Nara Institute of Science and Technology,Nara, Japan2, Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Japan3, Department of Biochemistry, Kitasato University School of Medicine, Kanagawa, Japan4, Department of Physiology, Faculty of Medicine, Saitama Medical University,Saitama, Japan5, Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan6, Kansai University7 Most growth factors are initially synthesized as precursors and subsequently processed to their mature form by proteolytic cleavage in the secretory pathway. Compared to that of the mature compartments, the biological role of pro-peptides is not well understood. In the present study, we aimed to elucidate the biological roles of the pro-peptide of brain-derived neurotrophic factor (BDNF), which promotes neuronal survival and the differentiation of developing neurons and modulates synaptic plasticity in the adult brain. We found that the BDNF pro-peptide directly facilitated hippocampal long-term depression (LTD) and elicited N-methyl-D-aspartate (NMDA)-induced endocytosis of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunit, GluA1, involved in LTD. Using a variety of techniques, we showed that the facilitation of LTD by the pro-peptide involved at least a pan-neurotrophin receptor, p75NTR. Since it has been previously reported that a common BDNF polymorphism (Val66Met), which substitutes a valine to a methionine at codon 66 in the BDNF pro-peptide, affected human brain function, we next examined whether the BDNF pro-peptide with Met mutation modulated hippocampal LTD. Unexpectedly, the mutant pro-peptide prevented low-frequent stimulation-induced LTD and NMDA-induced endocytosis of AMPA receptor subunits were blocked. The present study demonstrate that the BDNF pro-peptide facilitates hippocampal LTD through the activation of molecular mechanism of AMPARs and is a hitherto unknown ligand of synaptic plasticity.
P3-1-69 Leukemia inhibitory factorはinsulin-like growth factorを介してFibroblast growth factor 2の神経幹／前駆細胞の増殖作用を増強する Leukemia inhibitory factor enhances the effect of fibroblast growth factor 2 on proliferation of rat neural stem/progenitor cells via insulin-like growth factors ○島田ひろき1, 島村英理子1, 東海林博樹2, 有川智博2, 東伸明1, 八田稔久1 ○Hiroki Shimada1, Eriko Simamura1, Hiroki Shoji2, Tomohiro Arikawa2, Nobuaki Higashi1, Toshihisa Hatta1 金沢医科大学　医学部　解剖学11, 金沢医科大学　一般教育機構　生命科学科目（生物学）2 Dept Anat, Kanazawa Med Univ, Ishikawa, Japan1, Dept Biol, Kanazawa Med Univ, Ishikawa, Japan2 We previously found that adrenocorticotropic hormone from the placenta induces leukemia inhibitory factor (LIF) secretion from rat embryonic nucleated red blood cells and that secreted LIF induces the proliferation of embryonic neural stem/progenitor cells (NSCs) in the fetal forebrain (Simamura, et al, 2010). We also reported that secreted LIF enhances the levels of insulin-like growth factor (IGF) 1 and IGF2, strong mitogens of NSCs, in the fetal cerebrospinal fluid and increases IGF gene expression in the dorsal cortex of the fetal forebrain (Neuro2011). Although fibroblast growth factor 2 (FGF2) is necessary for developmental NSC proliferation, we observed with the RNA microarray assay that LIF did not change FGF2 gene expression. We therefore assumed that LIF promotes the mitogenic effect of FGF2 in the development of fetal forebrain via IGFs. To elucidate whether LIF promotes the proliferation of NSCs by FGF2, we examined the effects of LIF using rat neurospheres. NSCs were prepared from the dorsal cortex of the rat fetal forebrain (14.5 days post-coitum) and cultured in a medium containing epidermal growth factor and FGF2 for the formation of neurospheres. After 4 days, the NSCs were cultured in the same medium but without FGF2 for an additional 24 h. Bromodeoxyuridine (BrdU) incorporation into neurospheres cultured in media containing FGF2 without or with LIF was measured. BrdU incorporation was increased by cotreatment with FGF2 and LIF compared with treatment with FGF2 alone. In addition, we observed that LIF increased gene expression of IGF1 and IGF2 in the neurospheres. Taken together, these results indicated that LIF enhances FGF2 action in NSC proliferation via IGF1 and IGF2.	P3-1-70 生物発光を利用したマウス脳内における脳由来神経栄養因子BDNF遺伝子発現変化の解析 Monitoring of brain-derived neurotrophic factor (BDNF) gene expression using bioluminescence imaging in mouse brain ○福地守1, 和泉宏謙2, 田中亜由美2, 井上蘭2, 森寿2, 前畑陽佑1, 津田正明1 ○Mamoru Fukuchi1, Hironori Izumi2, Ayumi Tanaka2, Ran Inoue2, Hisashi Mori2, Yosuke Maehata1, Masaaki Tsuda1 富山大院・医薬・分子神経生物1, 富山大院・医薬・分子神経科学2 Dept Biol Chem, Grad Sch of Med & Pharm Sci, Univ of Toyama, Toyama1, Dept Mol Neurosci, Grad Sch of Med & Pharm Sci, Univ of Toyama, Toyama2 Brain-derived neurotrophic factor (BDNF), a neurotrophin, plays a fundamental role in expressing a variety of neuronal functions in the brain. The expression of BDNF gene is controlled in a neuronal activity-dependent manner. And it has been demonstrated that the change in the BDNF expression is observed in the brain with neural disorders, such as Alzheimer's disease, depression, and epilepsy. Therefore, monitoring of BDNF gene expression in vivo would be useful for the analysis of changes in BDNF expression under physiological and pathological conditions in the brain. Here, we used a transgenic mouse strain to monitor BDNF expression using luciferase as in vivo imaging probe. We successfully detected bioluminescence signal from the head region of transgenic but not wild-type mice after administration of luciferin, a substrate for luciferase. Although the bioluminescence signal intensity tended to increase after saline administration, kainic acid-induced seizure significantly enhanced the intensity. In support, luciferase and endogenous BDNF mRNA expression increased 12 h after kainic acid administration. On the other hand, using a bioluminescence microscope, we detected the increase in signal intensity after induction of membrane depolarization in primary culture of cortical cells prepared from transgenic mice. The increase was completely prevented by nicardipine, a blocker of L-type voltage dependent calcium channels. These results indicate that BDNF gene expression can be continuously monitored using the transgenic mice both in vitro and in vivo, and the mice will be a powerful tool to screen chemical compounds which can influence BDNF expression.

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