研究者業績
基本情報
- 所属
- 鹿児島大学 大学院医歯学総合研究科 特任助教藤田医科大学 ゲノミクス医学センター 客員助教
- 連絡先
- k9125830
kadai.jp - 研究者番号
- 00878283
- ORCID ID
https://orcid.org/0000-0001-8282-2515- J-GLOBAL ID
- 202001016575419127
- researchmap会員ID
- R000001560
研究キーワード
4研究分野
4経歴
5-
2026年4月 - 現在
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2023年12月 - 現在
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2024年3月 - 2026年3月
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2015年6月 - 2024年2月
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2023年4月 - 2023年11月
主要な学歴
3受賞
2-
2019年9月
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2019年3月
論文
32-
Frontiers in public health 13 1509528-1509528 2025年BACKGROUND: Agricultural or gardening physical activity (AGPA) offers potential as a simple strategy to improve cardiovascular disease and dementia-related markers; however, the actual preventive effects remain unclear. Our objective was to investigate AGPA regarding related markers of cardiovascular disease and dementia using cross-sectional and interventional approaches. METHODS AND RESULTS: In Study 1, community-based older individuals were assessed, and 30 individuals who performed AGPA (AG group) and 30 1:1 age-, sex-, and objective activity-matched controls were cross-sectionally compared (mean age, 75 ± 6 y). Arterial stiffness (pulse wave velocity) was lower and hand-finger dexterity (pegboard test) was higher in the AG vs. control groups. The interventional results of Study 2 (secondary analysis of a randomized controlled trial) confirmed that consistent AGPA might regress white matter hyperintensities in older individuals. CONCLUSION: Our findings suggest that consistent AGPA perse may improve cardiovascular disease and dementia-related markers in older healthy individuals via arterial stiffness, cognitive function, and cerebral white matter status. This information could have major implications for integrated strategies for lifelong health. SECONDARY ANALYSIS OF CLINICAL TRIALS STUDY 2: Study for Decreasing Depressive Symptoms and Increasing Memory Performance in the older adults (Trial registration number UMIN000018547, Date of registration 2015/08/07), URL: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000021462.
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PLOS ONE 19(5) e0303833-e0303833 2024年5月20日Fatigue can lead to several health issues and is particularly prevalent among elderly individuals with chronic inflammatory conditions. Ninjin’yoeito, a traditional Japanese herbal medicine, is used to address fatigue and malaise, anorexia, and anemia. This study aimed to examine whether relieving inflammation in the brain and skeletal muscle of senescence-accelerated mice prone 8 (SAMP8) could reduce fatigue-like conditions associated with aging. First, SAMP8 mice were divided into two groups, with and without ninjin’yoeito treatment. The ninjin’yoeito-treated group received a diet containing 3% ninjin’yoeito for a period of 4 months starting at 3 months of age. At 7 months of age, all mice underwent motor function, treadmill fatigue, and behavioral tests. They were then euthanized and the skeletal muscle weight, muscle cross-sectional area, and concentration of interleukin (IL)-1β and IL-1 receptor antagonist (IL-1RA) in both the brain and skeletal muscle were measured. The results showed that the ninjin’yoeito-treated group had higher motor function and spontaneous locomotor activity than the untreated group did and ran for significantly longer in the treadmill fatigue test. Moreover, larger muscle cross-sectional area, lower IL-1β concentrations, and higher IL-1RA concentrations were observed in both the brain and skeletal muscle tissues of the ninjin’yoeito-treated group than in the untreated group. The results suggest that ninjin’yoeito improves age-related inflammatory conditions in both the central and peripheral tissues and reduces fatigue.
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Frontiers in aging neuroscience 16 1337397-1337397 2024年INTRODUCTION: Cerebral white matter hyperintensities (WMHs) are commonly found in the aging brain and have been implicated in the initiation and severity of many central nervous system diseases. Furthermore, an increased WMH volume indicates reduced brain health in older adults. This study investigated the association between WMH volume and physical activity in older adults with depressive symptoms (DS) and mild memory impairment (MMI). Factors associated with the WMH volume were also investigated. METHODS: A total of 57 individuals aged over 65 years with DS and MMI were included in this study. The participants underwent magnetic resonance imaging to quantify WMH volumes. After WMH volume was accumulated, normalized to the total intracranial volume (TIV), the percentage of WMH volume was calculated. In addition, all participants wore a triaxial accelerometer for 2 weeks, and the average daily physical activity and number of steps were measured. The levels of blood biomarkers including cortisol, interleukin-6 (IL-6), brain-derived insulin-like growth factor-1, and brain-derived neurotrophic factor were measured. Motor and cognitive functions were also assessed. RESULTS: Faster maximum walking speed and longer time spent engaged in moderate physical activity were associated with a smaller percent of WMH volume, whereas higher serum IL-6 levels were associated with a larger percent of WMH volume. The number of steps per day, time spent engaged in low levels of physical activity, cognitive function, and all other measured biomarkers were not significantly associated with percent of WMH volume. DISCUSSION: Higher blood inflammatory cytokine levels, shorter duration of moderate physical activity, and lower maximum walking speed were associated with a higher percent of WMH volume. Our results provide useful information for maintaining brain health in older adults at a high risk of developing dementia and may contribute to the development of preventive medicine for brain health.
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Aging 15(21) 11740-11763 2023年11月9日5'-Adenosine monophosphate-activated protein kinase (AMPK) is a metabolic sensor that serves as a cellular housekeeper; it also controls energy homeostasis and stress resistance. Thus, correct regulation of this factor can enhance health and survival. AMPK signaling may have a critical role in aging-associated brain diseases. Some in vitro studies have shown that 1,5-anhydro-D-fructose (1,5-AF) induces AMPK activation. In the present study, we experimentally evaluated the effects of 1,5-AF on aging-associated brain diseases in vivo using an animal model of acute ischemic stroke (AIS), stroke-prone spontaneously hypertensive rats (SHRSPs), and the spontaneous senescence-accelerated mouse-prone 8 (SAMP8) model. In the AIS model, intraperitoneal injection of 1,5-AF reduced cerebral infarct volume, neurological deficits, and mortality. In SHRSPs, oral administration of 1,5-AF reduced blood pressure and prolonged survival. In the SAMP8 model, oral administration of 1,5-AF alleviated aging-related decline in motor cognitive function. Although aging reduced the expression levels of peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α) and brain-derived neurotrophic factor (BDNF), we found that 1,5-AF activated AMPK, which led to upregulation of the PGC-1α/BDNF pathway. Our results suggest that 1,5-AF can induce endogenous neurovascular protection, potentially preventing aging-associated brain diseases. Clinical studies are needed to determine whether 1,5-AF can prevent aging-associated brain diseases.
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Arthritis research & therapy 25(1) 168-168 2023年9月14日BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease associated with aging, which often leads to joint stiffness and disability. Exercise is one of the most important non-pharmacological treatments and is prescribed as an indispensable treatment for OA. However, whether physical exercise is beneficial for preventing the progression of OA symptoms with age is poorly understood. We investigated the effects of exercise on spontaneously developed knee OA using male senescence-accelerated mouse prone 8 (SAMP8). METHODS: To examine age-related changes in the knee joints of SAMP8, knee articular cartilage changes, synovitis, knee joint flexion and extension angles, swelling, walking ability, and quadriceps muscle atrophy were analyzed at 3, 5, 7, and 9 months. SAMP8 were required to run at a speed of 10 m/min for 15 min/day from 7 to 9 months of age. The knee joint pathologies and symptoms of exercising and non-exercising mice were compared by histological, immunohistochemical, and morphometrical analyses. RESULTS: The mice presented with various histological changes, including cartilage destruction, osteocyte formation, synovitis, declined joint angles, and swelling. Notably, medial and posterior cartilage destruction was more severe than that of the lateral and anterior cartilage. Knee joint angles were significantly correlated with the histological scores (modified Mankin and OARSI, osteophyte formation and synovial lining cell layer). Exercise did not attenuate cartilage degeneration in the medial and posterior tibial plateau, although the articular cartilage of the anterior and lateral tibial plateau and its histological scores was remained and significantly improved, respectively, by exercise. Exercise suppressed the age-related decline of collagen type II-positive areas in the remaining articular cartilage and improved the OA symptoms. Exercise reduced the expression of monocyte chemoattractant protein (MCP)-1 and tumor necrosis factor (TNF)-α positive macrophages in the synovium. CONCLUSION: This study revealed that SAMP8 developed spontaneous knee OA with age, which resembled the disease symptoms in humans. Low-intensity exercise temporarily alleviated degeneration of the remaining cartilage, synovitis, and age-related decreases in knee flexion angle, stride length, and muscle atrophy in SAMP8. However, exercise during OA progression with age may cause mechanical stress that could be both beneficial and detrimental to joint health.
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Neuroscience letters 808 137297-137297 2023年6月21日Physical exercise is beneficial for preventing Alzheimer's disease (AD) and cognitive decline through several mechanisms, including suppression of neuroinflammation and neuronal loss in the hippocampus. Despite these exercise-induced benefits in AD pathology, less attention has been paid to the importance of maintaining exercise and the consequences of detraining. This study aimed to investigate the effects of early exercise intervention and detraining on age-related cognitive decline and its protective mechanisms using senescence-accelerated mouse prone 8 (SAMP8). These mice were divided to four groups: no-exercise (No-Ex, n = 9), 4 months (4 M)-detraining (n = 11), 2 months (2 M)-detraining (n = 11), and long-term exercise (LT-Ex, n = 13). Age-related cognitive decline was prevented in the LT-Ex group compared with the No-Ex group through the suppression of neuronal loss, enhanced brain-derived neurotrophic factor (BDNF), and inhibition of neuroinflammation corresponding to reduced M1 and increased M2 microglia in the hippocampus. No significant differences were observed in cognitive function between the detraining and No-Ex groups. However, the 2 M-detraining group showed increased BDNF positive area in the CA1 region and the enhancement of anti-inflammatory M2 phenotype microglia. In contrast, no statistically beneficial exercise-induced changes in the hippocampus were observed in the 4 M-detrainig group. These results showed that early exercise intervention prevented age-related cognitive deficits in AD progression by suppressing neuronal loss and neuroinflammation in the hippocampus. Exercise-induced benefits, including the anti-inflammation in the hippocampus, may be retained after exercise cessation, even if exercise-induced beneficial effects decline in a time-dependent manner.
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Journal of ethnopharmacology 302(Pt B) 115927-115927 2023年2月10日ETHNOPHARMACOLOGICAL RELEVANCE: Ninjin'yoeito (NYT), a traditional Japanese Kampo medicine consisting of 12 herbs, has been reported to improve cognitive dysfunction, depression, and neurological recovery in patients with neurovascular diseases such as Alzheimer's disease and stroke. Several studies have reported that the NYT components exert neurotrophic, neurogenic, and neuroprotective effects. In addition, exercise enhances neuroprotection and functional recovery after stroke. Rehabilitative exercises and pharmacological agents induce neurophysiological plasticity, leading to functional recovery in stroke patients. These reports indicate that NYT treatment and exercise may promote functional recovery following stroke through their beneficial effects. However, no study has determined the effects of NYT and the possible mechanisms of neurorepair and functional recovery after stroke. AIM OF THE STUDY: This study aimed to investigate the combined effects of NYT and exercise on neuroprotection and functional recovery and the underlying mechanisms in a rat ischemic stroke model. MATERIALS AND METHODS: Stroke was induced with 60-min middle cerebral artery occlusion (MCAO) followed by reperfusion in adult male Sprague-Dawley rats. After stroke, the rats were assigned to four groups: ischemia reperfusion (IR), NYT, exercise (Ex), and NYT + Ex. NYT-treated rats were fed a diet containing 1% NYT one day after stroke. Exercise was performed using a motorized treadmill for 5 days a week (8-15 m/min, 20 min/day), starting 3 days after stroke. The NYT treatment and exercise were continued for 4 weeks after the stroke. Infarct volume, neurological deficits, sensorimotor functions, expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase A (TrkA) and B (TrkB), caspase-3 activity, and the p-Akt/Akt ratio were examined by immunohistochemistry and western blotting. RESULTS: Compared to the IR group, all treated groups indicated reduced infarct volumes. The NYT + Ex group showed significantly improved waking time and beam walking score compared with the IR group. The expression of NGF/TrkA/p-TrkA and BDNF/TrkB was significantly increased in the NYT + Ex group compared with those in the IR group, whereas the number of caspase-3 positive cells around the lesion was significantly lower in the NYT + Ex group than in the IR group. In addition, the ratio of p-Akt/Akt was significantly higher in the NYT + Ex group than in the IR group. CONCLUSIONS: This study suggests that NYT in combination with exercise provides neuroprotective effects and improves sensorimotor function by stimulating NGF/TrkA and BDNF/TrkB, and by activating the Akt pathway in ischemic stroke of rats. NYT may be an effective adjunctive agent in post-stroke rehabilitation.
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Scientific reports 13(1) 2158-2158 2023年2月7日Remote ischemic perconditioning (RIPerC) is a novel neuroprotective method against cerebral infarction that has shown efficacy in animal studies but has not been consistently neuroprotective in clinical trials. We focused on the temporal regulation of ischemia-reperfusion by RIPerC to establish an optimal method for RIPerC. Rats were assigned to four groups: 10 min ischemia, 5 min reperfusion; 10 min ischemia, 10 min reperfusion; 5 min ischemia, 10 min reperfusion; and no RIPerC. RIPerC interventions were performed during ischemic stroke, which was induced by a 60-min left middle cerebral artery occlusion. Infarct volume, sensorimotor function, neurological deficits, and cellular expressions of brain-derived neurotrophic factor (BDNF), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and caspase 3 were evaluated 48 h after the induction of ischemia. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) was also performed. RIPerC of 10 min ischemia/10 min reperfusion, and 5 min ischemia/10 min reperfusion decreased infarct volume, improved sensorimotor function, decreased Bax, caspase 3, and TUNEL-positive cells, and increased BDNF and Bcl-2 expressions. Our findings suggest RIPerC with a reperfusion time of approximately 10 min exerts its neuroprotective effects via an anti-apoptotic mechanism. This study provides important preliminary data to establish more effective RIPerC interventions.
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International journal of molecular sciences 23(19) 2022年9月23日Physical frailty is an aging-related clinical syndrome involving decreases in body weight, mobility, activity, and walking speed that occurs in individuals with sarcopenia and is accelerated by increased oxidative stress. Ninjin'yoeito, a traditional Japanese Kampo medicine, is used for treating conditions, including anemia and physical weakness. Here, we investigated whether ninjin'yoeito could improve physical frailty by controlling oxidative stress in the senescence-accelerated mouse prone 8 (SAMP8) model. First, SAMP8 mice were divided into two groups, ninjin'yoeito treated and untreated, with the former consuming a diet containing 3% ninjin'yoeito from 3 months of age. At 7 months of age, body weight, motor function, locomotor activity, and mean walking speed were measured. Subsequently, mice were euthanized and measured for muscle weight, 8-hydroxy-2'-deoxyguanosine levels in muscle and brain, and cleaved caspase-3 expression in brain. The results showed reductions in weight, locomotor function, locomotion, and average walking speed in the untreated group, which were significantly improved by ninjin'yoeito. Furthermore, 8-hydroxy-2'-deoxyguanosine levels were reduced in muscle and brain from ninjin'yoeito-treated mice, compared with the levels in untreated mice; cleaved caspase-3 expression was similarly reduced in brain from the treated mice, indicating reduced apoptosis. Our findings suggest that ninjin'yoeito inhibits sarcopenia-based physical frailty through its antioxidant effects.
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International journal of molecular sciences 23(3) 2022年1月22日 査読有り筆頭著者Knee arthrofibrosis is a common complication of knee surgery, caused by excessive scar tissue, which results in functional disability. However, no curative treatment has been established. E8002 is an anti-adhesion material that contains L-ascorbic acid, an antioxidant. We aimed to evaluate the efficacy of E8002 for the prevention of knee arthrofibrosis in a rat model, comprising injury to the surface of the femur and quadriceps muscle 1 cm proximal to the patella. Sixteen male, 8-week-old Sprague Dawley rats were studied: in the Adhesion group, haemorrhagic injury was induced to the quadriceps and bone, and in the E8002 group, an adhesion-preventing film was implanted between the quadriceps and femur after injury. Six weeks following injury, the restriction of knee flexion owing to fibrotic scarring had not worsened in the E8002 group but had worsened in the Adhesion group. The area of fibrotic scarring was smaller in the E8002 group than in the Adhesion group (p < 0.05). In addition, the numbers of fibroblasts (p < 0.05) and myofibroblasts (p < 0.01) in the fibrotic scar were lower in the E8002 group. Thus, E8002 reduces myofibroblast proliferation and fibrotic scar formation and improves the range of motion of the joint in a model of knee injury.
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Scientific reports 11(1) 19648-19648 2021年10月4日 査読有りThe gut microbiota has tremendous potential to affect the host's health, in part by synthesizing vitamins and generating nutrients from food that is otherwise indigestible by the host. 1,5-Anhydro-D-fructose (1,5-AF) is a monosaccharide with a wide range of bioactive potentials, including anti-oxidant, anti-inflammatory, and anti-microbial effects. Based on its potential benefits and minimal toxicity, it is anticipated that 1,5-AF will be used as a dietary supplement to support general health. However, the effects of 1,5-AF on the gut microbiota are yet to be clarified. Here, using an unbiased metagenomic approach, we profiled the bacterial taxa and functional genes in the caecal microbiota of mice fed a diet containing either 2% 1,5-AF or a reference sweetener. Supplementation with 1,5-AF altered the composition of the gut microbiota, enriching the proportion of Faecalibacterium prausnitzii. 1,5-AF also altered the metabolomic profile of the gut microbiota, enriching genes associated with nicotinamide adenine dinucleotide biosynthesis. These findings support the potential benefits of 1,5-AF, but further studies are required to clarify the impact of 1,5-AF on health and disease.
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International journal of molecular sciences 22(18) 2021年9月14日 査読有りMitochondrial functional abnormalities or quantitative decreases are considered to be one of the most plausible pathogenic mechanisms of Parkinson's disease (PD). Thus, mitochondrial complex inhibitors are often used for the development of experimental PD. In this study, we used rotenone to create in vitro cell models of PD, then used these models to investigate the effects of 1,5-anhydro-D-fructose (1,5-AF), a monosaccharide with protective effects against a range of cytotoxic substances. Subsequently, we investigated the possible mechanisms of these protective effects in PC12 cells. The protection of 1,5-AF against rotenone-induced cytotoxicity was confirmed by increased cell viability and longer dendritic lengths in PC12 and primary neuronal cells. Furthermore, in rotenone-treated PC12 cells, 1,5-AF upregulated peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) expression and enhanced its deacetylation, while increasing AMP-activated protein kinase (AMPK) phosphorylation. 1,5-AF treatment also increased mitochondrial activity in these cells. Moreover, PGC-1α silencing inhibited the cytoprotective and mitochondrial biogenic effects of 1,5-AF in PC12 cells. Therefore, 1,5-AF may activate PGC-1α through AMPK activation, thus leading to mitochondrial biogenic and cytoprotective effects. Together, our results suggest that 1,5-AF has therapeutic potential for development as a treatment for PD.
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Brain structure & function 226(7) 2169-2180 2021年9月 査読有りPreconditioning exercise prior to stroke exerts neuroprotection, which is an endogenous strategy that leads the brain cells to express several intrinsic factors and inhibits their apoptosis. However, it is unclear how long these benefits last after exercise cessation. The aim of this study was to investigate the effects of detraining on preconditioning exercise-induced neuroprotective potential after stroke. Rats were trained using a treadmill for aerobic exercise 5 days each week for 3 weeks, and their neuroprotective effects were examined until 3 weeks after exercise cessation. Stroke was induced by 60 min of left middle cerebral artery occlusion at 3 days, 1, 2, and 3 weeks after exercise cessation. Infarct volume, neurological deficits, sensorimotor function, expression levels of brain-derived neurotrophic factor (BDNF), hypoxia-induced factor-1α (HIF-1α), glial fibrillary acidic protein (GFAP), and P2X7 receptors, and apoptosis activity were examined using immunohistochemical and western blot analyses. Preconditioning exercise significantly reduced infarct volume and ameliorated sensorimotor function after stroke, and its beneficial effects were observed until 2 weeks after exercise cessation. The expression level of BDNF in the ischemic brain was significantly upregulated at 3 days after exercise cessation; however, the expression levels of HIF-1α, GFAP, and P2X7 receptor were significantly increased until 2 weeks after exercise cessation; thereby, significant anti-apoptotic effects were lost at 3 weeks of detraining. Our findings suggest that preconditioning exercise-induced neuroprotective potential may be lost shortly after exercise cessation. Neuroprotection through intrinsic protective factors, such as BDNF and HIF-1α, may provide different neuroprotective mechanisms in a time-dependent manner during detraining.
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Molecular neurobiology 58(11) 5602-5617 2021年8月9日 査読有りSubarachnoid hemorrhage (SAH) is a catastrophic form of stroke responsible for significant morbidity and mortality. Oxidative stress, inflammation, and neuronal apoptosis are important in the pathogenesis of early brain injury (EBI) following SAH. Preconditioning exercise confers neuroprotective effects, mitigating EBI; however, the basis for such protection is unknown. We investigated the effects of preconditioning exercise on brain damage and sensorimotor function after SAH. Male rats were assigned to either a sham-operated (Sham) group, exercise (Ex) group, or no-exercise (No-Ex) group. After a 3-week exercise program, they underwent SAH by endovascular perforation. Consciousness level, neurological score, and sensorimotor function were studied. The expression of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), 4-hydroxynonenal (4HNE), nitrotyrosine (NT), ionized calcium-binding adaptor molecule 1 (Iba1), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), interleukin 1β (IL-1β), 14-3-3γ, p-β-catenin Ser37, Bax, and caspase-3 were evaluated by immunohistochemistry or western blotting. The terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick end labeling (TUNEL) assay was also performed. After SAH, the Ex group had significantly reduced neurological deficits, sensorimotor dysfunction, and consciousness disorder compared with the No-Ex group. Nrf2, HO-1, and 14-3-3γ were significantly higher in the Ex group, while 4HNE, NT, Iba1, TNF-α, IL-6, IL-1β, Bax, caspase-3, and TUNEL-positive cells were significantly lower. Our findings suggest that preconditioning exercise ameliorates EBI after SAH. The expression of 4HNE and NT was reduced by Nrf2/HO-1 pathway activation; additionally, both oxidative stress and inflammation were reduced. Furthermore, preconditioning exercise reduced apoptosis, likely via the 14-3-3γ/p-β-catenin Ser37/Bax/caspase-3 pathway.
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Experimental neurology 337 113590-113590 2021年3月 査読有りIt is well known that physical exercise reduces the risk of Alzheimer's disease (AD) and age-related cognitive decline. However, its mechanisms are still not fully understood. This study aimed to investigate the effect of aging and rotarod exercise (Ex) on cognitive function and AD pathogenesis in the hippocampus using senescence-accelerated mice prone 8 (SAMP8). Cognitive functions clearly declined at 9-months of age. Amyloid-beta (Aβ) deposition, neuronal loss, and glia activation-induced neuroinflammation increased with aging. The rotarod Ex prevented the decline of cognitive functions corresponding to the suppression of Aβ deposition, neuroinflammation, neuronal loss, inducible nitric oxide synthase (NOS) activities, and neuronal NOS activities. In addition, the rotarod Ex suppressed proinflammatory M1 phenotype microglia and A1 phenotype astrocytes. Our findings suggest that low-intensity motor balance and coordination exercise prevented age-related cognitive decline in the early stage of AD progression, possibly through the suppression of hippocampal Aβ deposition, neuronal loss, oxidative stress, and neuroinflammation, including reduced M1 and A1 phenotypes microglia and astrocytes.
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International journal of environmental research and public health 17(15) 2020年7月24日 査読有りThe present study investigates the diurnal profiles of locomotive and household activities in older adults with musculoskeletal disorders (MSDs) using an accelerometer. Furthermore, we examined the effect of chronic pain on their diurnal profiles in both activities. Seventy-one older adults with MSDs (73-89 years) were included in this cross-sectional survey, and 25 age-matched older adults (75-86 years) were selected as healthy older adults. The daily physical activities, including steps walked and locomotive and household activity intensities, were recorded using a triaxial accelerometer in terms of metabolic equivalent task-hours per week (MET-h/week). The diurnal profiles of steps and locomotive activities in older adults with MSDs were considerably lower than those of healthy older adults. In contrast, there was no significant decline in household activity. However, the locomotive and household activities were reduced by severe chronic pain. This survey demonstrated that the diurnal profiles of household activity in older people with MSDs as well as those in age-matched healthy older adults were maintained. Furthermore, severe chronic pain influenced both activities. Therefore, the maintenance of household activity throughout the day, as well as the management of chronic pain, may be important strategies for the promotion of physical activity in older people with MSDs.
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International journal of molecular sciences 21(11) 2020年6月1日 査読有りPerineural adhesions leading to neuropathy are one of the most undesirable consequences of peripheral nerve surgery. However, there are currently no widely used compounds with anti-adhesive effects in the field of peripheral nerve surgery. E8002 is a novel, anti-adhesive, multi-layer membrane that contains L-ascorbic acid (AA). Here, we investigated the effect and mechanism of E8002 in a rat sciatic nerve adhesion model. A total of 21 rats were used. Six weeks after surgery, macroscopic adhesion scores were significantly lower in the E8002 group (adhesion procedure followed by nerve wrapping with E8002) compared to the E8002 AA(-) group (adhesion procedure followed by nerve wrapping with the E8002 membrane excluding AA) and adhesion group (adhesion procedure but no treatment). Correspondingly, a microscopic examination revealed prominent scar tissue in the E8002 AA(-) and adhesion groups. Furthermore, an in vitro study using human blood samples showed that AA enhanced tissue-type, plasminogen activator-mediated fibrinolysis. Altogether, these results suggest that E8002 may exert an anti-adhesive action via AA and the regulation of fibrinolysis.
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Journal of neuroinflammation 17(1) 40-40 2020年1月29日 査読有り筆頭著者BACKGROUND: Midkine (MK) is a multifunctional cytokine found upregulated in the brain in the presence of different disorders characterized by neuroinflammation, including neurodegenerative disorders and ischemia. The neuroinflammatory response to traumatic brain injury (TBI) represents a key secondary injury factor that can result in further neuronal injury. In the present study, we investigated the role of endogenous MK in secondary injury, including neuroinflammation, immune response, and neuronal apoptosis activity, after TBI. METHODS: Wild type (Mdk+/+) and MK gene deficient (Mdk-/-) mice were subjected to fluid percussion injury for TBI models and compared at 3, 7, and 14 days after TBI, in terms of the following: brain tissue loss, neurological deficits, microglia response, astrocytosis, expression of proinflammatory M1 and anti-inflammatory M2 microglia/macrophage phenotype markers, and apoptotic activity. RESULTS: As opposed to Mdk+/+ mice, Mdk-/- mice reported a significantly reduced area of brain tissue loss and an improvement in their neurological deficits. The ratios of the Iba1-immunoreactive microglia/macrophages in the perilesional site were significantly decreased in Mdk-/- than in the Mdk+/+ mice at 3 days after TBI. However, the ratios of the glial fibrillary acidic protein immunoreactive area were similar between the two groups. The M1 phenotype marker (CD16/32) immunoreactive areas were significantly reduced in Mdk-/- than in the Mdk+/+ mice. Likewise, the mRNA levels of the M1 phenotype markers (TNF-α, CD11b) were significantly decreased in Mdk-/- mice than in Mdk+/+ mice. Furthermore, flow cytometry analysis identified the M2 markers, i.e., CD163+ macrophages cells and arginase-1+ microglia cells, to be significantly higher in Mdk-/- than in Mdk+/+ mice. Finally, the ratios of apoptotic neurons were significantly decreased in the area surrounding the lesion in Mdk-/- than in Mdk+/+ mice following TBI. CONCLUSION: Our findings suggest that MK-deficiency reduced tissue infiltration of microglia/macrophages and altered their polarization status thereby reducing neuroinflammation, neuronal apoptosis, and tissue loss and improving neurological outcomes after TBI. Therefore, targeting MK to modulate neuroinflammation may represent a potential therapeutic strategy for TBI management.
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Neurological research 41(6) 510-518 2019年6月 査読有りOBJECTIVE: Preconditioning exercise can exert neuroprotective effects after stroke; however, the effects of exercise intensity, frequency, duration are unknown. We investigated the neuroprotective effect of different frequency preconditioning exercise on neuronal apoptosis after cerebral ischemia in rats. METHODS: Rats were divided into the following five groups: 5 times a week of exercise (5/w-Ex) group, 3 times a week of exercise (3/w-Ex) group, once a week of exercise (1/w-Ex) group, no exercise (No-Ex) group, and intact control (control) group. Rats were made to run on a treadmill for 30 min per day at a speed of 25 m/min for 3 weeks. After the running program, the rats were subjected to 60-min left middle cerebral artery occlusion. Two days after ischemia, the cerebral infarct volume, neurological and motor function, Bcl-2-associated X protein (Bax)/B-cell lymphoma 2 (Bcl-2) ratio, expression of caspase-3, and TUNEL positive cells were examined in the cerebral cortex surrounding the ischemic zone. RESULTS: The 3/w-Ex and 5/w-Ex groups showed significantly reduced infarct volumes compared with the No-Ex group, but the 1/w-Ex group did not. In addition, the 3/w-Ex and 5/w-Ex groups had improved neurological scores and sensorimotor function compared with the No-Ex group. The Bax/Bcl-2 ratio, expression of caspase-3, and TUNEL-positive cells significantly decreased in the penumbra area in the 3/w-Ex or 5/w-Ex groups compared with the No-Ex group. DISCUSSION: Our findings suggested that three times or more per week of high-intensity preconditioning exercise exert neuroprotective effects through the downregulation of the Bax/Bcl-2 ratio and caspase-3 activation after stroke. ABBREVIATIONS: TUNEL: terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick and labeling; MCAO:middle cerebral artery occlusion; BAX:Bcl-2-associated X protein; Bcl-2: B-cell lymphoma 2; TTC: 2,3,5-triphenyltetrazorlium chloride.
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Brain structure & function 224(2) 727-738 2019年3月 査読有り14-3-3γ is an important early ischemia-inducible protective factor against ischemic cell death in cerebral cortical neurons. We investigated the anti-apoptosis mechanism of enhanced 14-3-3γ mediated by preconditioning exercise-induced brain ischemic tolerance after stroke. Rats were assigned to four groups: exercise and ischemia (Ex group), ischemia and no exercise (No-Ex group), exercise and no ischemia (Ex-only group), and no exercise and ischemia (control group). Rats were trained on a treadmill for 5 days a week for 3 weeks (running speed, 25 m/min; running duration, 30 min/day). After the exercise program, stroke was induced by left middle cerebral artery occlusion. The infarct volume, neurological deficits, and motor function, as well as expression levels of hypoxia-induced factor-1α (HIF-1α), 14-3-3γ, P2X7 receptors, p-β-catenin Ser37, Bax, and caspase 3 were evaluated by immunohistochemistry and western blotting. The expression of HIF-1α and 14-3-3γ significantly increased in neurons and astrocytes in the Ex-only group. HIF-1α was co-expressed with P2X7 receptor- and GFAP-positive astrocytes. After stroke, the Ex group had significantly reduced brain infarction. HIF-1α and 14-3-3γ significantly increased in the Ex group compared to the No-Ex group. In addition, p-β-catenin Ser37 significantly increased following elevated 14-3-3γ; in contrast, Bax and caspase 3 were significantly reduced in the Ex group. Our findings suggest that preconditioning exercise prior to ischemia induces neuron- and astrocyte-mediated brain ischemic tolerance through increased expression of HIF-1α and 14-3-3γ, which are intrinsic protective factors; the upregulated 14-3-3γ induced by preconditioning exercise reduces ischemic neuronal cell death through the 14-3-3γ/p-β-catenin Ser37/Bax/caspase 3 anti-apoptotic pathway.
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Brain structure & function 224(2) 739-740 2019年3月 査読有りIn the original publication of the article, both the Fig. 2e and Fig. 7e have been published incorrectly and the correct figures are given below.
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Scientific reports 8(1) 15844-15844 2018年10月26日 査読有りUric acid (UA) therapy may prevent early ischemic worsening after acute stroke in thrombolysis patients. The aim of this study was to examine the influence of UA on the thrombolytic efficacy of alteplase in human blood samples by measuring thrombolysis under flow conditions using a newly developed microchip-based flow-chamber assay. Human blood samples from healthy volunteers were exposed to UA, alteplase, or a combination of UA and alteplase. Whole blood and platelet-rich plasma were perfused over a collagen- and thromboplastin-coated microchip, and capillary occlusion was monitored with a video microscope and flow-pressure sensor. The area under the curve (extent of thrombogenesis or thrombolysis) at 30 minutes was 92% lower in the UA-alteplase-treated group compared with the alteplase-treated group. D-dimers were measured to evaluate these effects in human platelet-poor plasma samples. Although hydrogen peroxide significantly decreased the elevation of D-dimers by alteplase, UA significantly inhibited the effect of hydrogen peroxide. Meanwhile, rat models of thromboembolic cerebral ischemia were treated with either alteplase or UA-alteplase combination therapy. Compared with alteplase alone, the combination therapy reduced the infarct volume and inhibited haemorrhagic transformation. UA enhances alteplase-mediated thrombolysis, potentially by preventing oxidative stress, which inhibits fibrinolysis by alteplase in thrombi.
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International journal of molecular sciences 19(5) 2018年5月18日 査読有りNeuropathic pain after spinal surgery, so-called failed back surgery syndrome, is a frequently observed common complication. One cause of the pain is scar tissue formation, observed as post-surgical epidural adhesions. These adhesions may compress surrounding spinal nerves, resulting in pain, even after successful spinal surgery. E8002 is an anti-adhesive membrane. In Japan, a clinical trial of E8002 is currently ongoing in patients undergoing abdominal surgery. However, animal experiments have not been performed for E8002 in spinal surgery. We assessed the anti-adhesive effect of E8002 in a rat laminectomy model. The dura matter was covered with an E8002 membrane or left uncovered as a control. Neurological evaluations and histopathological findings were compared at six weeks postoperatively. Histopathological analyses were performed by hematoxylin⁻eosin and aldehyde fuchsin-Masson Goldner staining. Three assessment areas were selected at the middle and margins of the laminectomy sites, and the numbers of fibroblasts and inflammatory cells were counted. Blinded histopathological evaluation revealed that adhesions and scar formation were reduced in the E8002 group compared with the control group. The E8002 group had significantly lower numbers of fibroblasts and inflammatory cells than the control group. The present results indicate that E8002 can prevent epidural scar adhesions after laminectomy.
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Journal of pain research 11 281-291 2018年 査読有りBackground: Exercise regimens are established methods that can relieve neuropathic pain. However, the relationship between frequency and intensity of exercise and multiple cellular responses of exercise-induced alleviation of neuropathic pain is still unclear. We examined the influence of exercise frequency on neuropathic pain and the intracellular responses in a sciatic nerve chronic constriction injury (CCI) model. Materials and methods: Rats were assigned to four groups as follows: CCI and high-frequency exercise (HFE group), CCI and low-frequency exercise (LFE group), CCI and no exercise (No-Ex group), and naive animals (control group). Rats ran on a treadmill, at a speed of 20 m/min, for 30 min, for 5 (HFE) or 3 (LFE) days a week, for a total of 5 weeks. The 50% withdrawal threshold was evaluated for mechanical sensitivity. The activation of glial cells (microglia and astrocytes), expression of brain-derived neurotrophic factor (BDNF) and μ-opioid receptor in the spinal dorsal horn and endogenous opioid in the midbrain were examined using immunohistochemistry. Opioid receptor antagonists (naloxone) were administered using intraperitoneal injection. Results: The development of neuropathic pain was related to the activation of glial cells, increased BDNF expression, and downregulation of the μ-opioid receptor in the ipsilateral spinal dorsal horn. In the No-Ex group, neuropathic pain showed the highest level of mechanical hypersensitivity at 2 weeks, which improved slightly until 5 weeks after CCI. In both exercise groups, the alleviation of neuropathic pain was accelerated through the regulation of glial activation, BDNF expression, and the endogenous opioid system. The expression of BDNF and endogenous opioid in relation to exercise-induced alleviation of neuropathic pain differed in the HFE and LFE groups. The effects of exercise-induced alleviation of mechanical hypersensitivity were reversed by the administration of naloxone. Conclusion: The LFE and HFE program reduced neuropathic pain. Our findings indicated that aerobic exercise-induced alleviated neuropathic pain through the regulation of glial cell activation, expression of BDNF in the ipsilateral spinal dorsal horn, and the endogenous opioid system.
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Behavioural brain research 303 9-18 2016年4月15日 査読有りPreconditioning exercise can exert neuroprotective effects after stroke. However, the mechanism underlying these neuroprotective effects by preconditioning exercise remains unclear. We investigated the neuroprotective effects of preconditioning exercise on brain damage and the expression levels of the midkine (MK) and brain-derived neurotrophic factor (BDNF) after brain ischemia. Animals were assigned to one of 4 groups: exercise and ischemia (Ex), no exercise and ischemia (No-Ex), exercise and no ischemia (Ex-only), and no exercise and intact (Control). Rats ran on a treadmill for 30 min once a day at a speed of 25 m/min for 5 days a week for 3 weeks. After the exercise program, stroke was induced by a 60 min left middle cerebral artery occlusion using an intraluminal filament. The infarct volume, motor function, neurological deficits, and the cellular expressions levels of MK, BDNF, GFAP, PECAM-1, caspase 3, and nitrotyrosine (NT) were evaluated 48 h after the induction of ischemia. The infarct volume, neurological deficits and motor function in the Ex group were significantly improved compared to that of the No-Ex group. The expression levels of MK, BDNF, GFAP, and PECAM-1 were enhanced in the Ex group compared to the expression levels in the No-Ex group after brain ischemia, while the expression levels of activated caspase 3 and NT were reduced in the area surrounding the necrotic lesion. Our findings suggest that preconditioning exercise reduced the infract volume and ameliorated motor function, enhanced expression levels of MK and BDNF, increased astrocyte proliferation, increased angiogenesis, and reduced neuronal apoptosis and oxidative stress.
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九州理学療法士・作業療法士合同学会誌 2016 142-142 2016年<p>【目的】</p><p>高齢になると何らかの骨関節疾患を有している場合が多く,特に,自営業を営む農村部在住高齢者の中には要介護状態にならないように,在宅での生活を送りながら近隣の整形外科医院で外来リハビリテーションを行っている者も少なくない。痛みは運動機能低下に関連し,特に下肢関節痛や腰痛を有する高齢者では運動機能の低下や活動量の低下により転倒のリスクが高まり,活動や参加の制限を引き起こすことが考えられる。そこで本研究の目的は,痛みの程度に着目し,地域在住高齢者の運動機能,身体活動量との特性について明らかにすることである。</p><p>【方法】</p><p>対象は種々の疾患により下肢関節痛および腰痛を有して整形外科医院に通院しているが,ADL の自立している65 歳以上の地域在住高齢者 30 名 ( 男性 : 7 名,女性 :23 名,平均年齢 : 80.0 歳 ) とした。評価項目は疼痛の程度,運動機能,1 週間の日常での身体活動量とした。身体活動量の測定前に感じた痛みの程度を NumericRating Scale(NRS)を用いて評価し,1 ~ 4 点の軽度群(10 名,男性 : 2 名,女性 : 8 名,平均年齢 :78.2 歳),5~6 点の中等度群(10 名,男性 : 3 名,女性 :7 名,平均年齢 : 79.5 歳),7 ~ 10 点の高度群(10 名,男性 : 1 名,女性 : 9 名,平均年齢 : 82.4 歳)に分類した。運 動 機 能 は 開 眼 片 脚 立 位 時 間,Time up and go(TUG) test, 30 秒 椅 子 か ら の 立 ち 上 が りテ スト(30-sec chair stand test: CS-30)を測定した。身体 活 動 量 は 3 次 元 加 速 度 センサ(オムロン社 製,Active style pro HJA-750C) を一週間装着してもらい,歩数,歩行時間,エクササイズ(Ex)量を評価した。Ex 量とは身体活動量を表す単位で,3.0METs 以上の活動強度 × 時間で表される。姿勢の変化を伴わない活動は歩行活動 Ex 量として,姿勢の変化を伴う活動は生活活動 Ex 量として計測される。分析は,軽度群,中等度群,高度群の 3 群における運動機能,身体活動量を比較した。統計学的検定には一元配置分散分析を用い,有意水準は5%とした。</p><p>【結果】</p><p>本研究の対象者の全員が膝・股関節痛,腰痛などを重複して訴えていた。運動機能は痛みの程度が強いほど有意に低下しており,開眼片脚立位時間,TUG,CS-30の全項目で,高度群の値は軽度群と比較して有意に低下していた (p< 0.05)。身体活動量は,痛みの程度が強いほど 1 日当たりの歩数や歩行時間は減少していた。1 週間当たりの歩行活動 Ex 量は歩数や歩行時間と同様に痛みの程度が強いほど減少する傾向を示したが,生活活動Ex 量は痛みの程度に関わらず大きく減少しなかった。</p><p>【考察】</p><p>今回の結果より,痛みの程度は運動機能の低下や日常における身体活動量の低下に大きく関係することが示された。また,歩行活動 Ex 量は痛みの程度が強いほど大きく減少していたが,家事動作の活動量を表す生活活動 Ex量は大きく変化しなかった。これは,疼痛により歩行活動は低下しているが,生活活動動作は痛みが強くても日々行っている高齢者が多いことを示唆している。痛みの程度は運動機能の低下,抑うつなどの心理面の障害に影響を及ぼすだけでなく,日常での歩行活動量の低下を生じる可能性がある。</p><p>【まとめ】</p><p>ADL はほぼ自立しているが,痛みを有して外来リハを行っている地域在住高齢者は多くみられる。今回,高齢者の痛みの程度は生活活動量の低下より,歩行活動量の低下に大きく関係している可能性が示唆された。高齢者の場合,病状の増悪や転倒などが運動機能低下に関与しており,今後は転倒との関連についても検討していきたい。</p><p>【倫理的配慮,説明と同意】</p><p>対象者に本研究の目的および内容について説明し同意を得た上で研究を実施した。また,本研究は鹿児島大学医学部倫理委員会の承認を得て行った。</p>
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理学療法学Supplement 2015 384-384 2016年【はじめに,目的】我々は第50回の本学会で,脳梗塞発症前運動は脳梗塞縮小効果があり,そのメカニズムとしてペナンブラ領域における神経栄養因子Midkine(MK)やBrain-derived neurotrophic factor(BDNF)の発現増加を報告した。しかし,神経保護作用には種々の要因が複雑に関係している。今回,神経栄養因子の発現,グリア増生,血管増生,アポトーシス,酸化ストレスに着目して,脳梗塞発症前の定期的な運動による脳梗塞後の神経保護作用機序について検討した。【方法】実験動物にはSD系雄性ラット34匹(平均体重280.1±44.9g)を用いた。無作為に,①運動+脳梗塞群(Ex群:n=11),②非運動+脳梗塞群(No-Ex群n=11),③運動のみ(Ex-only群n=6),④運動も脳梗塞も行わない群(Control群:n=6)に分けた。運動群はトレッドミル運動(25m/min,30分/日,5回/週)を3週間行った。No-Ex群とControl群は3週間自由飼育した。3週後,60分間の虚血,再灌流により脳梗塞モデルを作製した。Ex-only群とControl群はストレスの指標である血中コルチゾール濃度を測定した。脳梗塞作成48時間後に,神経学的評価や運動-感覚機能評価(Beam Walking,Rotarod,テープテスト)を行った。脳を採取しTTC染色後,脳梗塞巣の体積を測定した。MK,BDNF,アストロサイトのマーカーであるGFAP,微小血管のマーカーであるPECAM-1,アポトーシスのマーカーであるCaspase-3,フリーラジカルによる組織障害のバイオマーカーである3-Nitrotyrosine(3-NT)の抗体を用いて免疫組織化学染色を行った。ペナンブラ領域における陽性細胞面積を定量化した。統計学的検定は一元配置分散分析後,多重比較を行い,有意水準は5%とした。【結果】血中コルチゾール濃度は運動群と非運動群の間に有意差は認められなかった。脳梗塞巣の体積はEx群がNo-Ex群と比べて有意に縮小していた。Beam walkingやテープテストはEx群で有意に改善していた。免疫組織化学染色の結果,Ex-only群やControl群の間に有意差は観察されなかった。Ex群はNo-Ex群に比べ,MK,BDNF,GFAP,PECAM-1免疫陽性細胞面積が有意に増加していた。Ex群のCaspase-3や3-NT免疫陽性細胞面積はNo-Ex群と比較して有意に減少していた。【結論】ストレスのない定期的な運動により脳梗塞巣の縮小効果や運動-感覚機能の改善が認められた。そのメカニズムとして,MK,BDNFの発現増加,アストロサイトの活性化促進,血管増生の促進,ペナンブラ領域のアポトーシス抑制,酸化ストレス抑制が脳梗塞後早期の神経保護作用に関与していることが示唆された。
MISC
36担当経験のある科目(授業)
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2023年4月 - 2023年8月整形外科学各論(非常勤) (鹿児島大学)
共同研究・競争的資金等の研究課題
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日本学術振興会 科学研究費助成事業 若手研究 2022年4月 - 2025年3月
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日本学術振興会 科学研究費助成事業 基盤研究(C) 2021年4月 - 2024年3月
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日本学術振興会 科学研究費助成事業 研究活動スタート支援 2020年9月 - 2022年3月