ポスター
F. 神経系の疾患 1
F. Disorders of the Nervous System 1 |
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| 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-086
小脳顆粒細胞特異的Liver Kinase B1（LKB1）欠損マウスの週齢変化に伴う運動機能障害
Depletion of LKB1 in the cerebellar granule cells induces locomotor dysfunction in aged mice
*喜多村 まゆ(1)、萩原 明(2,1)、浜田 駿(1)、大塚 稔久(1)
1. 山梨大学、2. 東京理科大学
*Mayu Kitamura(1), Akari Hagiwara(2,1), Shun Hamada(1), Toshihisa Ohtsuka(1)
1. University of Yamanashi, 2. Tokyo University of Science
Keyword: LKB1, Rotarod test, cerebellum, parallel fiber synapse
The serine/threonine kinase Liver Kinase B1 (LKB1), known as a tumor suppressor, plays crucial roles in cell proliferation, differentiation, and polarity by activating the downstream AMPK (AMP-activated protein kinase) subfamily. In the nervous system, LKB1 is also essential for the functional neural circuits by regulating the migration of neurons and the synaptogenesis. In a previous study, the loss of LKB1 in cerebellar granule cell precursors caused expansion of the cerebellar cortex with hyperplasia of the lobule and serious locomotor dysfunction. However, the causal relationship between synaptic transmission and locomotor dysfunction has not been well clarified. To investigate the mechanism of LKB1-mediated synaptic formation and maintenance, we newly generated LKB1 conditional knockout mice (cKO mice) crossed with mice expressing Cre in cerebellar granule cells after the postnatal developmental period. Intriguingly, our cKO mice showed little deficiency in the coordinated movement at the age of 4-5 weeks, however, the cKO mice showed a remarkable decrease of locomotor function after 20 weeks of age in the rotarod test. The morphological analysis using immunohistochemistry with presynaptic protein (vGluT1) antibody showed reduced thickness in the molecular and granule cell layers in the cKO, but the area was not significantly different. We further investigated the parallel fiber Purkinje cell synapses in the molecular layer at the electron microscopic level and found that both density and size were significantly larger in cKO mice. These results indicate that LKB1 in cerebellar granule cells is involved in the morphogenesis of the cerebellum including the synapse formation and maintenance, which would cause the disability of locomotion in the old mice. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-087
Clavulanic Acid Corrects Neuronal Deficits in an Epilepsy Rat Model
*Jing-Yi Yao(1), Wen-Yuan Liu(1), Pin-Jiun Lin(1), Yu-Shiuan Tzeng(1), Yun-Ju Hsieh(1), Xin-Qi Fu(1), Yong-Zhu Zhuang (1), Ying-Jui Ho(1)
1. Chung Shan Medical University
Keyword: Epilepsy, Clavulanic Acid, cytochrome oxidase, subthalamic nucleus
According to the report of WHO, epilepsy is the most common chronic brain disease and affects more than 50 million people worldwide of all ages. Excessive levels of excitatory glutamate and insufficient of inhibitory GABA are involved in the pathophysiology of epilepsy. Clavulanic Acid (CA), a ß-lactamase inhibitor, has been demonstrated facilitating GLT-1 expression, therefore improves the reuptake of glutamate. The purpose of the study was to evaluate the effects of CA on neuronal density and activity in the pentylenetetrazol (PTZ)-induced epilepsy rat model through histological assessment. Male Wistar rats received intraperitoneal injection of PTZ (35 mg/kg, every other day, IP, for 13 days) to induce kindling epilepsy model. After 4 times of PTZ injection, the rats received daily treatment with CA (1 or 10 mg/kg, IP), low dose of VPA (50 mg/kg, IP), or with combination of CA (1 mg/kg) and VPA (50 mg/kg), for 7 consecutive days. The brain tissues were analyzed by Nissl and cytochrome oxidase staining. The result showed that epilepsy rats showed decreased neuronal density in the hippocampus and hyperactivity in subthalamic nucleus. Treatment with CA inhibited the above neuronal lose and hyperactivity. Interestingly, we found an increased neuronal activity in basolateral amygdala after CA10 treatment. In conclusion, the data may support the potential of CA in preventing neuronal deficits in epilepsy. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-088
脳損傷後、脳皮質全般に起こる脳脊髄液循環不全の網羅的解析
Cortical-wide impairment of "the Glymphatic System" after focal brain injury
*イ ヒョンソク(1)、Masae Azuma(1)、Kota Shinzaki(1)、Rina Yamane(1)、Mitsuhiro Morita(1)
*Hyunseok Lee(1), Masae Azuma(1), Kota Shinzaki(1), Rina Yamane(1), Mitsuhiro Morita(1)
1. Faculty of Sci, Kobe university, Kobe, Japan
Keyword: cerebrospinal fluid circulation, glymphatic system, focal brain injury, image segmentation
The glymphatic system, which is a continuous flow of cerebrospinal fluid (CSF) and cerebral interstitial fluid (ISF) connected by perivascular spaces (PVSs) is suggested as a waste clearance mechanism of the brain lacking lymphatic capillaries. Localized tissue damage by focal brain injury is supposed to impair the glymphatic system and affect ionic, nutrient, and waste conditions that influence brain function. Accumulating evidence indicates the associations of CSF flows labeled by fluorescence or MRI tracers with cognitive functions during dementia and sleep cycle. However, current histological and MRI analysis of CSF flow could not assess overall PVSs after focal brain injury because PVSs are not intact after conventional procedures for histological analysis, while the spatial resolution of MRI is insufficient for visualizing PVSs.
To overcome this problem, we developed a novel method and data analysis framework for the cortical-wide measurement of the glymphatic system. Rather than slicing, brains were flattened and cleared after fluorescence labeling of CSF compartment and vasculature. 3D images of whole cortical vasculature were constructed by tiling Z stack images obtained by confocal microscopy. Individual penetrating vessels were extracted by a custom-built python program.
As a result, we extracted five hundred penetrating vessels from each hemisphere and successfully measured colocalized fluorescence reflecting CSF. Those CSF signals still exist even after branching into first order. Injured brains had intact vasculature except for the lesion core in which the vessel marker was almost disappeared. Although vasculature remains intact, the CSF signal was decreased after a week after injury within both distal regions from the lesion in the ipsilateral and surprisingly contralateral area. This global reduction of CSF signals recovered by four weeks after injury at the surface area but not recovered in PVS area. This differentiated recovery indicates that CSF to the brain surface and PVS may be under different control mechanisms. One explanation is the enhanced CSF drainage to basal lymph node and coincidental reduction of CSF flow to PVS. These global reductions of CSF signal in parenchyma would cause accumulation of metabolic waste such as amyloid-beta and aggravate pathological progress after injury. Furthermore, the present results may explain remote effects of focal brain injury, including cognitive and psychiatric dysfunctions. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-089
多発性硬化症モデル動物におけるMaresin-1の保護効果
Protective effect of Maresin-1 in a mouse model of multiple sclerosis
*菅原 季起(1,2)、田中 勇希(2,4)、北條 慎太郎(2)、村上 正晃(2,3,4)、南 雅文(1)
1. 北海道大学薬学部薬理学研究室、2. 北海道大学遺伝子病制御研究所・大学院医学院 分子神経免疫学分野、3. 生理学研究所 分子神経免疫研究部門、4. 量子科学技術研究開発機構 量子免疫学グループ
*Toshiki Sugawara(1,2), Yuki Tanaka(2,4), Shintaro Hojyo(2), Masaaki Murakami(2,3,4), Masabumi Minami(1)
1. Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, 2. Molecular Psychoneuroimmunology, Institute for Genetic Medicine, Hokkaido University, 3. Division of Molecular Neuroimmunology, National Institute for Physiological Sciences, 4. Quantum Immunology Group, National Institutes for Quantum Science and Technology
Keyword: Experimental autoimmune encephalomyelitis, Inflammatory, Interleukin-6, Blood Brain Barrier
In recent years, it has been shown that chronic inflammation may be involved in the pathology of various neurodegenerative and psychiatric diseases. On the other hand, recent studies have discovered new lipid mediators, such as resolvins, protectins, and maresins, which are produced from omega-3 polyunsaturated fatty acids and have the effects to calm inflammation. If any of these lipid mediators could enhance the barrier function of the blood brain barrier, such mediators could be useful in the treatment of neurodegenerative/psychiatric diseases caused by the infiltration of immune cells into the central nervous system. Thus, in this study, we first examined the effects of several metabolites of omega-3 polyunsaturated fatty acids on the BBB function in the in vitro assay system using mouse brain microvascular endothelial cells, and found that maresin-1 upregulated the barrier function. Next, we examined the effect of maresin-1 on experimental autoimmune encephalomyelitis (EAE) which is commonly used as a mouse model of multiple sclerosis. EAE was induced in C57BL/6 mice (6-11 weeks) by subcutaneous injection of myelin oligodendrocyte glycoprotein (MOG) peptide (0.4 mg/mice) with complete Freund’s adjuvant on day 0. Pertussis toxin (0.4 μg/mice) was injected intravenously via the tail on days 0, 2, and 7. Intraperitoneal injection of maresin-1 (300 ng/day) once daily from day 0 to the end of the experiment delayed the onset of EAE compared to the vehicle-injected group. It is known that the pathogenesis of EAE involves the "IL-6 amplifier", which induces sustained inflammation in the central nervous system through the continuous production of inflammatory factors such as IL-6 in non-immune cells by the simultaneous activation of the transcription factors STAT3 and NF-κB. We examined the effect of maresin-1 on IL-6 production in the BC-1 cell line, an endothelial cell line derived from mouse femoral cortex, and found that maresin-1 suppressed IL-6 gene expression. These results suggest that maresin-1 may act on vascular endothelial cells to delay onset of EAE. Further studies are needed to elucidate the molecular and cellular mechanisms of the protective effect of maresin-1 against EAE. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-090
アデノ随伴ウイルス発現系を用いた筋萎縮性側索硬化症のモデル開発
Development of a model for amyotrophic lateral sclerosis using an adeno-associated virus expression system
*高瀬 未菜(1,3)、野中 隆(1)、毛内 拡(2,3)、長谷川 成人(1)
1. 東京都医学総合研究所認知症プロジェクト、2. お茶の水女子大学理学部生物学科、3. お茶の水女子大学大学院人間文化創成科学研究科
*Mina Takase(1,3), Takashi Nonaka(1), Hiromu Monai(2,3), Masato Hasegawa(1)
1. Tokyo Metropolitan Institute of Medical Science, Dementia research project, Tokyo, Japan, 2. Department of Biology, Faculty of Science, Tokyo, Japan, 3. Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
Keyword: virus vector
Amyotrophic lateral sclerosis (ALS) and some forms of frontotemporal lobar degeneration (FTLD) are neurodegenerative diseases with pathological TDP-43 aggregates in neurons and oligodendrocytes, collectively referred to as TDP-43 proteinopathies. A number of missense mutations in the TDP-43 gene have been reported in familial forms of ALS/FTLD, providing genetic links between abnormalities of TDP-43 and neurodegeneration. TDP-43 is a heterogenous ribonuclear protein (hnRNP). It is normally localized in the nucleus, but in the brains of patients, it accumulates in the cytoplasms and processes in a filamentous, phosphorylated, and ubiquitinated state. Although a number of transgenic mice overexpressing mutant TDP-43 have been generated to elucidate the mechanism of TDP-43 accumulation, they do not fully reproduce the accumulation of TDP-43 in the brains of patients. In this study, we aim to develop a model that reproduces abnormal accumulation of TDP-43 by using an adeno-associated virus (AAV) expression system. We made AAV-PHP.eB vectors that specifically express TDP-43 or its mutants in neurons, astrocytes, or oligodendrocytes and conducted experiments to infect mouse primary cortical neuron cultures and mouse brains. The AAV expressing TDP-43 or its mutants were injected into the orbital venous plexus of mice, and one month later, the brains were investigated for immunohistochemical and biochemical analyses. Expression of the TDP-43 or the mutants lacking nuclear localizing signal (TDPΔNLS) were observed in the cerebral cortex and hippocampus. When AAVs expressing wild-type TDP-43 were administered at high concentrations, the mice were paralyzed of the hind legs and died within a month. Therefore, we will examine the appropriate concentrations of these AAV. We will also inoculate patient-derived TDP-43 filaments prepared from ALS/FTLD cases as seeds into the brains of AAV-infected mice and investigate the brain pathologies of these mice histologically and biochemically. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-091
Cdkl5キナーゼ不活性型ノックインマウスの脳波の線形および非線形解析
Linear and nonlinear analysis of EEG of the Cdkl5 kinase-dead knock-in mice
*井原 拓斗(1)、菅谷 佑樹(2)、田中 輝幸(1)
1. 東京大学大学院医学系研究科発達医科学教室、2. 東京大学大学院医学系研究科神経生理学教室
*Takuto Ihara(1), Yuki Sugaya(2), Teruyuki Tanaka(1)
1. Dept Developmental Med Sciences Grad Sch Med, Univ of Tokyo, Tokyo, Japan, 2. Dept Neurophysiology, Grad Sch Med, Univ of Tokyo, Tokyo, Japan
Keyword: EEG, linear and nonlinear analysis, developmental disorder, CDKL5
The Cyclin-dependent kinase-like 5 (CDKL5) gene encodes the CDKL5 protein, a serine/threonine kinase. Loss-of-function (LOF) mutations of CDKL5 cause CDKL5 deficiency disorder characterized by infantile-onset intractable epilepsy and severe developmental disorder. Previously we generated Cdkl5 knockout mice, and identified synaptic abnormalities at the microscopic level and behavioral abnormalities at the macroscopic level. However, mesoscopic, neural circuit mechanisms upon the LOF of CDKL5 are still not well understood.An electroencephalogram (EEG) directly represents the activity of neural circuits and should offer a biomarker to identify brain network disorders. In this study, we applied linear and nonlinear analysis of EEG to newly generated Cdkl5 kinase-dead knock-in (KI) mice to identify neurocircuit characteristics upon the loss of CDKL5 kinase activity at a mesoscopic level.We obtained epidural EEG from the somatosensory and prefrontal cortices of adult KI and wild-type mice and performed a linear, power spectrum analysis, and nonlinear, Recurrence plot and Recurrence Quantification Analysis (RQA) on the awake, resting state. The power spectrum analysis revealed an increase in the relative power of delta waves and a decrease in the relative power of alpha waves in the somatosensory field of the KI mice, which suggests that the developmental maturation of neurocircuits was impaired. By calculating the ratio of each frequency band power to the alpha band power (relative alpha ratio), significant increase of the delta/alpha ratio in the prefrontal and somatosensory cortices and beta/alpha ratio in the somatosensory cortex was revealed. By dividing the gamma band to low (30-49 Hz) and high (70-140 Hz) gamma bands and calculating the ratio between the two, we found that high gamma waves were relatively attenuated in the prefrontal cortex of KI mice.In the nonlinear analysis, there were no significant differences in the recurrence plots and the RQA parameters. However, combined analysis of multiple RQA parameters seems to be more effective in characterizing the chaotic dynamics of two genetic conditions and the analysis is underway.In summary, we identified several EEG abnormalities of Cdkl5 kinase-dead KI mice, which may be associated with learning and memory impairment, and provided possible biomarkers for CDKL5 deficiency disorder. A combination of multiple linear and nonlinear analyses of EEG may better capture altered activity of neural circuits. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-092
15q11-13領域重複ASDモデル動物のPrelimbic cortexにおける第V層錐体細胞の神経活動の特異的変化
Specific alteration of neural activity in the layer Vpyramidal neurons of the prelimbic cortex in the 15q dup ASD model animals.
*高橋 温志(1)、岩崎 華奈(1)、山中 由芽(1)、大谷 嘉典(1)、藤谷 昌司(1)
1. 島根大学
*Atsushi Takahashi(1), Hana Iwasaki(1), Yume Yamanaka(1), Yoshinori Otani(1), Masashi Fujitani(1)
1. shimane university
Keyword: 15q11-13 duplication, Axon initial segment, prelimbic cortex
Specific alteration of neural activity in the layer Vpyramidal neurons of the prelimbic cortex in the 15q dup ASD model animals. Atsushi Takahashi, Hana Iwasaki, Yume Yamanaka,Yoshinori Otani, Masashi FujitaniDepartment of Anatomy and Neuroscience, Faculty of Medicine, Shimane University Autism spectrum disorder (ASD) is a developmental disorder involving impairments in communication, reciprocal social interaction and restricted repetitive behaviors or interests. Duplication of human chromosome 15q11-13 region (15q dup) is a risk factor for ASD.The axon initial segment (AIS) is located at the proximal axon and contains a high density of ion channels, initiatingaction potentials. The AIS regulates neuronal excitability by changing its structure, such as length and position. Many studies reported that the abnormal AISs were observed in a variety of neurological diseases. We have preliminarily found that the abnormal AISswere observed in interneural circuits between the dorsal raphe nucleolus and the prelimbic cortex (PrL) of theventromedial prefrontal cortex (vmPFC) in 15q dup ASD model animals. In addition to the PrL, in this study, we measured the AIS length of the layer V pyramidal neurons in the infralimbic cortex (IL), another region of vmPFC. Interestingly, in the 15q ASD model animals, we found that the AIS length of the layer V pyramidal neurons was decreased in the PrL,but not in the IL. Furthermore, electrophysiological studies also demonstrated that frequency of action potentials in neurons of the PrL, but not the IL was decreased in 15q dup ASD model animals. These results suggested that altered neural activity oflayer V pyramidal neurons in the PrL may be importantfor behavioral abnormalities in 15q dup ASD model animals. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-093
核内受容体PPARαを標的とした統合失調症治療薬の開発
Development of therapeutic drugs for schizophrenia targeting PPAR alpha
*吉町 文子(1,2)、前川 素子(2)、大西 哲生(3)、大和田 祐二(2)
1. 東北大学医学部、2. 東北大学大学院医学系研究科 器官解剖学分野、3. 東京医科歯科大学 難治疾患研究所
*Fumiko Yoshimachi(1,2), Motoko Maekawa(2), Tetsuo Ohnishi(3), Yuji Owada(2)
1. Dept Med, Univ of Tohoku, Sendai, Japan, 2. Dept of Organ Anatomy, Grad Sch Med, Univ of Tohoku, Sendai, Japan, 3. Medical Research Inst, Tokyo Medical and Dental Univ, Tokyo, Japan
Keyword: Peroxisome proliferator-activated receptor α (PPARα), Therapeutic target, Synaptogenesis, Gene expression
Schizophrenia is one of the major psychiatric disorders. Although its pathophysiology is still unclear and currently no fundamental cure is known, evidence has suggested the association between abnormal lipid metabolism and schizophrenia. PPAR (peroxisome proliferator-activated receptor) signaling is known to regulate lipid metabolism, and we previously identified the loss-of-function mutations of the PPARA gene encoding nuclear receptor PPAR𝛼, a transcription factor activated by its endogenous ligands, in patients with schizophrenia and demonstrated that Ppara knockout mice exhibited schizophrenia-like behavioral and histological phenotypes. These results suggest the implication of nuclear receptor PPAR𝛼 in the pathogenesis of schizophrenia. The current study aimed to test the possibility that pharmacological manipulation of PPAR𝛼 could mitigate schizophrenia symptoms using a mouse model. First, we generated a mouse model of schizophrenia by chronically and intraperitoneally administration of an N-methyl-D-aspartate (NMDA) receptors antagonist, MK-801. In this pharmacological model, MK-801 reduced interest in novel objects in the novel object recognition test (NORT). Histologically, the drug reduced spine density in the prefrontal cortex as reported in the postmortem brain of schizophrenia. Using this model, we indicated that a synthetic PPAR𝛼 agonist significantly ameliorated the MK-801-evoked behavioral and histological phenotypes. As the next step, we explored the mechanism by which the PPAR𝛼 agonist mitigated the spine pathology by MK-801. Since several lines of evidence have supported the crucial roles of glial cells in the spine dynamics and the pathology of schizophrenia, we examined whether the PPARα agonist modulated the expression of multiple genes known to regulate the spine dynamics using glial cell lines. As a result, the PPAR𝛼 agonist upregulated the expression of some of those genes. In conclusion, we demonstrated that 1) PPARα can be a therapeutic target of schizophrenia, 2) PPARα agonists can serve as therapeutic drugs for schizophrenia, and 3) PPARα agonists regulate neural function, probably by modulating the spine dynamics by expressional control in glial factors. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-094
抗うつ薬フルオキセチンは腹側海馬の神経同期活動を減少させる
Antidepressant fluoxetine reduces neuronal synchronization in the ventral hippocampus
*塩崎 裕美(1,2)、鍜冶 利幸(1)、池谷 裕二(3,4)、佐々木 拓哉(2,3)
1. 東京理科大学・薬学部、2. 東北大学大学院・薬学研究科、3. 東京大学大学院・薬学系研究科、4. 国立研究開発法人 情報通信研究機構 脳情報通信融合研究センター
*Hiromi Shiozaki(1,2), Toshiyuki Kaji(1), Yuji Ikegaya(3,4), Takuya Sasaki(2,3)
1. Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2. Grad Sch Pharmaceut Sci, Univ of Tohoku,Sendai, Japan, 3. Grad Sch Pharmaceut Sci, Univ of Tokyo,Tokyo, Japan
Keyword: ventral hippocampus, fluoxetine, memory, depression
Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) and has been considered to exert antidepressant effects by increasing serotonin concentration in the inter-synaptic cleft. However, the monoamine hypothesis has not been fully supported as there are a time lag between increases in brain serotonin levels after SSRI treatment and the expression of antidepressant effects. We hypothesized that the temporal inconsistency may be partly reconciled by memory mechanisms, especially in the hippocampus. A theory of memory suggests that learned memory needs to be consolidated into neuronal circuits by repeated reactivation of memory-encoding neuronal activity. If this mechanism operates for negative memory, it might exacerbate depressant symptoms. To support this idea, our previous study demonstrated that inhibition of the ventral hippocampus after stress experiences inhibits subsequent depression-like behavior in mice. Especially, we found that sharp wave ripples (SWRs), which represent synchronized neuronal spikes in the ventral hippocampus, are a primary neuronal activity pattern to mediate this effect. Here, we tested whether fluoxetine affects SWRs in the ventral hippocampus in resting mice. We found that fluoxetine administration significantly reduced the frequency of ventral hippocampus SWRs, while saline did not show such effects. These results suggest that fluoxetine inhibits SWR-induced neuronal reactivation, a potential substrate for memory consolidation, which might underlie an antidepressant effect. We now examine whether fluoxetine treatment reduces stress-related ventral hippocampal activity in a mouse model of depression. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-095
コルチコステロンの慢性投与におけるマウスの微生物叢-腸-脳軸への影響
Effects of chronic administration of corticosterone on the microbiota-gut-brain axis in mice
*韓 陶磊(1)、キュウ ブンゼン(1)、佐藤 健二郎(2)、児島 伸彦(1,2)
1. 東洋大学生命科学部生命科学科、2. 東洋大学生体医工学研究センター
*TAOLEI HAN(1), WENRAN QIU(1), KENJIRO SATO(2), NOBUHIKO KOJIMA(1,2)
1. Faculty of Life Sciences,Department of Life Sciences,Toyo University,Gunnma,Japan, 2. Research Center for Biomedical Engineering, Toyo University, Japan
Keyword: Microbiota-gut-brain axis, Corticosterone, Genes expression, Gut microbiota
Major depression is attributed to psychological and physical stress. Biological psychosocial model indicates that complex interactions of biological, psychological, and social factors lead to pathogenesis. It has been estimated that about 40% of the pathogenesis of depression is associated with genetic factors, and genetic variants can increase stress vulnerability. Although genetic factors, such as mutations in multiple genes, interact one another and may be risks for the onset, the underlying mechanism of pathogenesis of depression still remains unclear. On the other hand, external factors are also thought to be important for determining the vulnerability. There is growing evidence that the microbiota of the entire gastrointestinal tract (i.e., the gut microbiota) is associated with anxiety and depression. It has been suggested that the gut microbiota may influence brain function via neuroendocrine and neuroimmune pathways. In this study, we used corticosterone (CORT), which is a glucocorticoid secreted in the adrenal cortex by the activation of the hypothalamus-anterior pituitary-adrenal axis. Chronic administration of CORT can create depressive disorder mouse model. Several behavioral tests were performed in this model to assess anxiety and depressive behaviors. We also conducted systematic screening of gene expression levels of synaptic plasticity-related genes in the hippocampus and the gut microbiota, using the mouse synaptic plasticity RT² Profiler PCR Array (QIAGEN) and 16S rRNA gene next-generation sequencing. Our results indicate that chronic CORT administration results in changes of expression in several synaptic plasticity-related genes. A significant decrease in expression of these genes suggests that chronic stress causes reduced synaptic plasticity, being possibly associated with hippocampus atrophy and decreased hippocampal neurogenesis. In addition, meta 16S rRNA gene analysis of the gut microbiota revealed that chronic CORT-administered mice show the significant increase or decrease of 24 species (genus) of bacteria, that might be related to depressive behavior. For example, Firmicutes at phylum level were increased in CORT-administered mice, particularly g__Lachnospiraceae_UCG-001 at genus level, and this increase was also reported in depressive patients. In conclusion, our data provide additional evidence for the important role of microbiota-gut-brain axis in depression. The causal relationship between gene expression of the brain and changes in the composition of gut microbiota needs to be further investigated and may represent a novel target for future diagnostic and therapeutic interventions in mood disorders. | | 2022年6月30日 13:00～14:00 沖縄コンベンションセンター 展示棟 ポスター会場1
1P-096
IL-6ファミリーサイトカインがマウス血液脳関門機能に及ぼす影響
Effects of IL-6 family cytokines on mouse blood-brain barrier function
*三浦 佑慈(1)、濵田 奨(1)、坂之上 徳博(1)、南 雅文(2)
1. 北海道大学薬学部薬理学研究室、2. 北海道大学大学院薬学研究院薬理学研究室
*Yuji Miura(1), Sho Hamada(1), Norihiro Sakanoue(1), Masabumi Minami(2)
1. Dept Pharm, Hokkaido University, Hokkaido, Japan, 2. Grad Sch Pharm, Hokkaido University, Hokkaido, Japan
Keyword: BBB, Cytokine
The blood-brain barrier (BBB) regulates molecular trafficking from the circulating blood to the brain parenchyma. The BBB is basically composed of a monolayer of brain microvascular endothelial cells (BMECs), which connected to each other via tight junctions. IL-6 is one of the soluble factors produced by astrocytes, which are known to regulate BBB functions. We have previously shown that treatment with IL-6 family cytokines, leukemia inhibitory factor (LIF) and oncostatin M (OSM), attenuate the BBB function. We have also revealed that co-treatment with IL-6 and its soluble receptor (sIL-6R) significantly attenuates BBB function, while the attenuating effect of IL-6 alone on BBB function is very weak effect. In this study, we further examined the effects of IL-6 family cytokines on BBB function using a FITC-dextran (FD4) permeability test. In addition, to examine the cytotoxic effect of OSM on BMECs, we performed a cytotoxicity assay. C57/BL6 mice (3-4 weeks old) were used. For FD4 permeability test, in vitro BBB model was prepared by seeding BMECs onto Transwell inserts and was treated with IL-6, sIL-6R, IL-6+sIL-6R, LIF and OSM (300 ng/ml each). Fluorescent intensity of FD4 in the lower well media was measured. Among these cytokines, attenuating effect of OSM on BBB function was strongest. To examine whether the attenuating effect of OSM on BBB function is due to the cytotoxic effect of this cytokine, BMECs seeded to 96 well plates were treated with OSM (0.1, 1, 10, 100 ng/ml), and the cytotoxicity assay was performed using a WST-8/LDH assay kit. No cytotoxic effect of OSM was observed. We are now planning to examine the effects of IL-6 family cytokines, especially OSM, on BBB function in vivo using an Evans blue permeability assay. | | | |
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