若手道場
神経疾患の動物モデル |
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| 7月6日（木） 16:30-17:30 Room H
1W⑦-1
頚椎症性脊髄症のマウスモデルの確立とActeosideによる改善効果
Effects of acteoside on neurological disabilities in the mouse model of cervical spondylotic myelopathy
羽柴 圭悟, 東田 千尋
富山大学 和漢医薬学総合研究所 神経機能学領域
Keigo Hashiba, Chihiro Tohda
Section of Neuromedical Science, Inst. of Natural Med., Univ. of Toyama
Cervical spondylotic myelopathy (CSM) is the most common cause of neurological disability in worldwide, which is caused by chronic compression of the spinal cord. Disabilities are caused by neuronal damage and axonal loss. Therefore, we supposed that accomplishment of axonal growth is the most critical therapeutic strategy for CSM. Since our previous study suggested acteoside as a facilitator of axonal growth in spinal cord injury, this study aimed to investigate effects of acteoside on functional disability in CSM model mice.
The animal models of CSM reported so far have experimental disadvantages. First, we established a new mouse model of CSM. After laminectomy at C3-C5, the cervical cord was compressed by a mini screw. Motor functions decreased depth-dependently of the compression. The dysfunction was obvious at least 9 days and lasted at least 30 days. At the compressed center, GFAP-positive astrocytes increased, and NF-H positive axonal density decreased compared to sham-operated mice.
Since we succeeded establishing CSM model, acteoside 3 or 30 mg/kg/day was administered orally every day from 7 days after compression. In the 30 mg/kg acteoside group, motor function gradually improved during three weeks dosing, and significant improvement was observed at 28 days post-treatment. Histological evaluation and molecular mechanism are now under investigation. | | 7月6日（木） 16:30-17:30 Room H
1W⑦-2
軸索局在をもたらす Tau 発現の臨界期解析
Critical period to produce axonally localized physiological tau in mice brain
上田 遼之1,2, 山本 亮良1, 大石 康二3, 元山 純3, 宮坂 知宏1,2
1. 同志社大学生命医科学部 神経病理学研究室, 2. 同志社大学 神経変性疾患研究センター, 3. 同志社大学脳科学研究科 神経発生分子機能部門
Haruyuki Ueda1,2, Akira Yamamoto1, Koji Oishi3, Jun Motoyama3, Tomohiro Miyasaka1,2
1. Neuropathology Laboratory, Graduate School of Life and Medical Sciences, Doshisha University, 2. Center for Research in Neurodegenerative diseases, 3. Laboratory of Developmental Neurobiology, Graduate School of Brain Science, Doshisha University
Tau is a microtubule-binding protein that localizes to axons. However, tau is mis-localized to somatodendrites in affected neurons of Alzheimer’s disease (AD) and then form pathological inclusions. Therefore, unidentified mechanisms needed for selective localization of newly synthesized tau to axon may be disrupted in AD brains.
In neonatal brains, 3R isoform of tau is predominant in perinatal mice brain but disappeared and replaced by 4R isoform tau until P14. On the other hand, artificially expressed tau after brain maturation is mis-localized to somatodendrites. Thus, physiological tau localized in axons should be produced at appropriate period in brain development.
To identify the critical period of physiological tau expression, here we developed doxycycline (Dox) induced GFP-tau (human 0N4R isoform) expression model using TRE/Tet3G vector and In Utero Electroporation. Distributions of GFP-tau were analyzed GFP fluorescence or immunocytochemical staining. When Dox was intraperitoneally injected at P10, the expressed GFP-tau was preferentially distributed in the axons at P28. However, no signal was detected if GFP-tau had been expressed at P3.
These results indicated that tau in matured mice brain is produced at least after P3. We are currently investigating the limit of expression period that does not induce mis-localization of tau in late developmental stage. | | 7月6日（木） 16:30-17:30 Room H
1W⑦-3
MARK2によるミクログリアの反応調節とタウオパチーモデルにおける特異的なサブタイプでの発現
MARK2 regulates microglial responses and express specific subtypes of microglia in a mouse model of tauopathy
福地 葵1, 斎藤 太郎1,2, 淺田 明子1,2, 安藤 香奈絵1,2
1. 東京都立大学大学院 理学研究科 生命科学専攻 神経分子機能研究室, 2. 東京都立大学 理学部 生命科学科
Aoi Fukuchi1, Taro Saito1,2, Akiko Asada1,2, Kanae Ando1,2
1. Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University, 2. Department of Biological Sciences, Faculty of Science, Tokyo Metropolitan University
Microglia play homeostatic roles such as immune responses and phagocytosis of debris. At the same time, their excessive activation and release of pro-inflammatory cytokines can contribute to neuronal loss in neurodegenerative diseases. However, it is not fully understood how active microglia increase under disease conditions. Microtubule affinity-regulating kinase 2 (MARK2) belongs to an evolutionary conserved Ser/Thr kinase family and is reported to function in immune cells. In this study, we investigated the roles of MARK2 in microglial activation.We found that MARK2 activity is downregulated in the immortalized murine microglial cell line BV2 cells treated with LPS. MARK2 knockdown promotes pro-inflammatory cytokine release after LPS stimuli, suggesting that MARK2 inhibits immune responses in microglia. Immunostaining of MARK2 in a mouse model of tauopathy PS19 revealed that MARK2 was expressed in P2Y12R-positive homeostatic microglia and TREM2-positive disease-associated phagocytotic microglia but not in Iba1-positive inflammatory microglia.Our results suggest that MARK2 expression is negatively correlated with glial hyperactivation and pro-inflammatory cytokine release under neurodegenerative conditions. Downregulation of MARK2 may contribute to increases in pro-inflammatory microglia in diseased brains. | | 7月6日（木） 16:30-17:30 Room H
1W⑦-4
孤発性アルツハイマー病モデルマウスにおけるグリア細胞活性化の領域特異性
Region-specificity of glial cell activation in sporadic Alzheimer's disease mouse model
正井 加織1, 中山 裕太1, 進 浩太郎1, 菅原 千明2, 宮崎 育子1, 安原 隆雄2, 伊達 勲2, 浅沼 幹人1
1. 岡山大学 脳神経機構学, 2. 岡山大学 脳神経外科学
Kaori Masai1, Yuta Nakayama1, Kotaro Shin1, Chiaki Sugahara2, Ikuko Miyazaki1, Takao Yasuhara2, Isao Date2, Masato Asanuma1
1. Dept. of Medical Neurobiology., Okayama Univ., Okayama, Japan, 2. Dept. of Neurological Surgery., Okayama Univ., Okayama, Japan
In sporadic Alzheimer’s disease (sAD), pathological changes are seen in not only the hippocampus, but also the basal forebrain and other hippocampus-connected regions. Impairment of non-neuronal environment might contribute to its pathogenesis. We studied brain region-specific alternations of astrocytes and microglia using sAD mouse model with intracerebroventricular streptozotocin (icv-STZ) injections. Nine week-aged male ICR mice were given icv-STZ injections (3 mg/kg) on Days 1 and 3. We performed open field test, Morris water maze test, and forced swimming test on Days 24-36. On Day 38, all mice were sacrificed to conduct histological assessment. Significant decrease of neural progenitor cells was observed, suggesting adult neurogenesis dysfunction. Astrocytes and microglia were activated in the hippocampus, habenular nuclei, midline nuclei of thalamus, hypothalamus, and medial septum-diagonal band of Broca. In contrast, no significant neuronal damage was seen in the glia-activated areas except demyelination of the habenula. However, the behavioral tests did not show significant impairment of locomotor activity and spacial memory, or exacerbation of depression-like states. Since the astrocytes and microglia-activated brain regions were almost identical to the area damaged in sAD, our present study implied this regional selectivity of STZ might be related to the pathology. | |
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