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永井 裕崇
大学院医学研究科 医科学専攻
助教

研究者基本情報

■ 学位
  • 博士（医学）, 京都大学
■ 研究キーワード
  • 樹状突起
  • シナプス
  • 中央代謝系
  • 前頭前皮質
  • 老化
  • 精神疾患
  • ストレス
■ 研究分野
  • ライフサイエンス / 神経科学一般
  • ライフサイエンス / 薬理学

研究活動情報

■ 論文
  • Hirotaka Nagai
    Adapting to environmental changes and formulating behavioral strategies are central to the nervous system, with the prefrontal cortex being crucial. Chronic stress impacts this region, leading to disorders including major depression. This review discusses the roles for prefrontal cortex and the effects of stress, highlighting similarities and differences between human/primates and rodent brains. Notably, the rodent medial prefrontal cortex (mPFC) is analogous to the human subgenual anterior cingulate cortex (sgACC) in terms of emotional regulation, sharing similarities in cytoarchitecture and circuitry, while also performing cognitive functions similar to the human dorsolateral prefrontal cortex (DLPFC). It has been shown that chronic stress induces atrophic changes in the rodent mPFC, which mirrors the atrophy observed in the sgACC and DLPFC of depression patients. However, the precise alterations in neural circuitry due to chronic stress are yet to be fully unraveled. The use of advanced imaging techniques, particularly volume electron microscopy, is emphasized as critical for the detailed examination of synaptic changes, providing a deeper understanding of stress and depression at the molecular, cellular, and circuit levels. This approach offers invaluable insights into the alterations in neuronal circuits within the mPFC caused by chronic stress, significantly enriching our understanding of stress and depression pathologies.
    2024年07月, Microscopy (Oxford, England), 英語, 国際誌
    [査読有り][招待有り]
    研究論文（学術雑誌）

  • Io Horikawa, Hirotaka Nagai, Masayuki Taniguchi, Guowei Chen, Masakazu Shinohara, Tomohide Suzuki, Shinichi Ishii, Yoshio Katayama, Shiho Kitaoka, Tomoyuki Furuyashiki
    Despite the importance of lipid mediators in stress and depression and their link to inflammation, the influence of stress on these mediators and their role in inflammation is not fully understood. This study used RNA-seq, LC-MS/MS, and flow cytometry analyses in a mouse model subjected to chronic social defeat stress to explore the effects of acute and chronic stress on lipid mediators, gene expression, and cell population in the bone marrow and spleen. In the bone marrow, chronic stress induced a sustained transition from lymphoid to myeloid cells, accompanied by corresponding changes in gene expression. This change was associated with decreased levels of 15-deoxy-d12,14-prostaglandin J2, a lipid mediator that inhibits inflammation. In the spleen, chronic stress also induced a lymphoid-to-myeloid transition, albeit transiently, alongside gene expression changes indicative of extramedullary hematopoiesis. These changes were linked to lower levels of 12-HEPE and resolvins, both critical for inhibiting and resolving inflammation. Our findings highlight the significant role of anti-inflammatory and pro-resolving lipid mediators in the immune responses induced by chronic stress in the bone marrow and spleen. This study paves the way for understanding how these lipid mediators contribute to the immune mechanisms of stress and depression.
    2024年04月, Journal of pharmacological sciences, 154(4) (4), 279 - 293, 英語, 国内誌
    [査読有り]
    研究論文（学術雑誌）
    神戸大学リポジトリ（Kernel）へのリンク

  • Satoshi Akiyama, Hirotaka Nagai, Shota Oike, Io Horikawa, Masakazu Shinohara, Yabin Lu, Takashi Futamura, Ryota Shinohara, Shiho Kitaoka, Tomoyuki Furuyashiki
    Abstract Severe and prolonged social stress induces mood and cognitive dysfunctions and precipitates major depression. Neuroinflammation has been associated with chronic stress and depression. Rodent studies showed crucial roles of a few inflammation-related lipid mediators for chronic stress-induced depressive-like behaviors. Despite an increasing number of lipid mediators identified, systematic analyses of synthetic pathways of lipid mediators in chronic stress models have not been performed. Using LC–MS/MS, here we examined the effects of chronic social defeat stress on multiple synthetic pathways of lipid mediators in brain regions associated with stress susceptibility in mice. Chronic social defeat stress increased the amounts of 12-lipoxygenase (LOX) metabolites, 12-HETE and 12-HEPE, specifically in the nucleus accumbens 1 week, but not immediately, after the last stress exposure. The increase was larger in stress-resilient mice than stress-susceptible mice. The S isomer of 12-HETE was selectively increased in amount, indicating the role of 12S-LOX activity. Among the enzymes known to have 12S-LOX activity, only Alox12 mRNA was reliably detected in the brain and enriched in brain endothelial cells. These findings suggest that chronic social stress induces a late increase in the amounts of 12S-LOX metabolites derived from the brain vasculature in the nucleus accumbens in a manner associated with stress resilience.
    Springer Science and Business Media LLC, 2022年12月, Scientific Reports, 12(1) (1)
    [査読有り]
    研究論文（学術雑誌）
    神戸大学リポジトリ（Kernel）へのリンク

  • Yusuke Kawashima, Hirotaka Nagai, Ryo Konno, Masaki Ishikawa, Daisuke Nakajima, Hironori Sato, Ren Nakamura, Tomoyuki Furuyashiki, Osamu Ohara
    The evolution of mass spectrometry (MS) and analytical techniques has led to the demand for proteome analysis with high proteome coverage in single-shot measurements. Focus has been placed on data-independent acquisition (DIA)-MS and ion mobility spectrometry as techniques for deep proteome analysis. We aimed to expand the proteome coverage by single-shot measurements using optimizing high-field asymmetric waveform ion mobility spectrometry parameters in DIA-MS. With our established proteome analysis system, more than 10,000 protein groups were identified from HEK293 cell digests within 120 min of MS measurement time. Additionally, we applied our approach to the analysis of host proteins in mouse feces and detected as many as 892 host protein groups (771 upregulated/121 downregulated proteins) in a mouse model of repeated social defeat stress (R-SDS) used in studying depression. Interestingly, 285 proteins elevated by R-SDS were related to mental disorders. The fecal host protein profiling by deep proteome analysis may help us understand mental illness pathologies noninvasively. Thus, our approach will be helpful for an in-depth comparison of protein expression levels for biological and medical research because it enables the analysis of highly proteome coverage in a single-shot measurement.
    2022年05月, Journal of proteome research, 21(6) (6), 1418 - 1427, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Luisa de Vivo, William Marshall, Giulio Tononi, Chiara Cirelli
    Abstract There is molecular, electrophysiological, and ultrastructural evidence that a net increase in synaptic strength occurs in many brain circuits during spontaneous wake (SW) or short sleep deprivation, reflecting ongoing learning. Sleep leads instead to a broad but selective weakening of many forebrain synapses, thus preventing synaptic saturation and decreasing the energy cost of synaptic activity. Whether synaptic potentiation can persist or further increase after long sleep deprivation is unknown. Whether synaptic renormalization can occur during chronic sleep restriction (CSR) is also unknown. Here, we addressed these questions by measuring an established ultrastructural measure of synaptic strength, the axon-spine interface (ASI), in the primary motor cortex (M1) of (1) one-month-old adolescent mice CSR using a paradigm that decreases NREM and REM sleep by two/thirds; (2) in two-week-old mouse pups sleep deprived for 15 h, or allowed afterward to recover for 16 h. Both groups were compared with mice of the same age that were asleep or awake for a few hours (both sexes). The ASI size of CSR mice (n = 3) was comparable to that measured after SW or short sleep deprivation and larger than after sleep (n = 4/group). In pups, the ASI size increased after short sleep loss (n = 3) relative to sleep (n = 4), fell below sleep levels after long sleep deprivation (n = 4), and remained low after recovery (n = 3). Long sleep deprived pups also lost some weight. These results suggest that (1) severe sleep restriction is incompatible with synaptic renormalization; (2) very young mice cannot maintain high synaptic strength during prolonged wake.
    Society for Neuroscience, 2021年06月, eneuro, 8(4) (4), ENEURO.0077 - 21.2021
    [査読有り]
    研究論文（学術雑誌）

  • Midori Nagai, Hirotaka Nagai, Chisato Numa, Tomoyuki Furuyashiki
    Severe environmental and social stress induces dysregulation of sleep along with mood and cognitive disturbances. However, the role and mechanism of this sleep dysregulation remain elusive. Here we evaluated sleep-like inactivity measured by voluntary movements and its relationship to social behaviors in mice without or with social defeat stress as well as the stressed mice with subsequent sleep deprivation. Social defeat stress immediately induced sleep-like inactivity with decreased body temperature. In the social interaction test, the control mice showed high social interest and its correlation with social sniffing intensity, the latter of which indicates positive valence of social sniffing. After the stress, these social characteristics were maintained in stress-resilient mice, but disrupted in stress-susceptible mice, leading to social avoidance. Sleep deprivation after the stress decreased social sniffing intensity along with reduced social interest, but enhanced the exploratory activity with the positive valence of social sniffing. We also found by c-Fos immunohistochemistry that the stress activated sleep-related brain regions, the dorsomedial hypothalamus and ventrolateral periaqueductal gray. Collectively, these findings show that stress activates sleep-related brain regions and induces sleep-like inactivity, contributing to multiple roles of stress-induced sleep for social behaviors.
    2020年11月, Scientific reports, 10(1) (1), 19800 - 19800, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）
    神戸大学リポジトリ（Kernel）へのリンク

  • Yasumasa Okazaki, Shan Hwu Chew, Hirotaka Nagai, Yoriko Yamashita, Hiroki Ohara, Li Jiang, Shinya Akatsuka, Takashi Takahashi, Shinya Toyokuni
    Malignant mesothelioma (MM) is one of the most lethal tumors in humans. The onset of MM is linked to exposure to asbestos, which generates reactive oxygen species (ROS). ROS are believed to be derived from the frustrated phagocytosis and the iron in asbestos. To explore the pathogenesis of MM, peritoneal MM was induced in rats by the repeated intraperitoneal injection of iron saccharate and nitrilotriacetate. In the present study, we used microarray techniques to screen the microRNA (miR) expression profiles of these MM. We observed that the histological subtype impacted the hierarchical clustering of miR expression profiles and determined that miR-199/214 is a distinctive feature of iron saccharate-induced sarcomatoid mesothelioma (SM). Twist1, a transcriptional regulator of the epithelial-mesenchymal transition, has been shown to activate miR-199/214 transcription; thus, the expression level of Twist1 was examined in iron-induced and asbestos-induced mesotheliomas in rats. Twist1 was exclusively expressed in iron saccharate-induced SM but not in the epithelioid subtype. The Twist1-miR-199/214 axis is activated in iron saccharate-induced and asbestos-induced SM. The expression levels of miR-214 and Twist1 were correlated in an asbestos-induced MM cell line, suggesting that the Twist1-miR-199/214 axis is preserved. MeT5A, an immortalized human mesothelial cell line, was used for the functional analysis of miR. The overexpression of miR-199/214 promoted cellular proliferation, mobility and phosphorylation of Akt and ERK in MeT5A cells. These results indicate that miR-199/214 may affect the aggressive biological behavior of SM.
    2020年06月, Cancer science, 111(6) (6), 2016 - 2027, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Chisato Numa, Hirotaka Nagai, Masayuki Taniguchi, Midori Nagai, Ryota Shinohara, Tomoyuki Furuyashiki
    We recently reported that dopamine D1 receptor in the medial prefrontal cortex (mPFC) is activated by subthreshold social defeat stress and suppresses the induction of depressive-like behavior in mice. However, which mPFC projection(s) mediates this antidepressant-like effect remains poorly understood. Here we show that social defeat stress specifically increased c-Fos expression, a marker for neuronal activity, in distinct brain regions involved in emotional regulation, relative to novelty-induced exploration. Among these brain areas, D1 knockdown in the mPFC decreased social defeat stress-induced c-Fos expression in the interstitial nucleus of the posterior limb of the anterior commissure (IPAC), a subregion of the extended amygdala. Using retrograde adeno-associated virus vectors and transgenic mice expressing Cre recombinase under the D1 promoter, we also found that D1-expressing deep-layer pyramidal neurons in the mPFC send direct projections to the IPAC. These findings indicate that social defeat stress specifically activates neurons in distinct brain areas, among which the IPAC is regulated by dopamine D1 receptor in the mPFC perhaps through direct projections. Thus, this study provides hints toward identifying neural circuits that underlie antidepressant-like effects of stress-induced dopamine D1 receptor signaling in the mPFC.
    2019年11月, Scientific reports, 9(1) (1), 16670 - 16670, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）
    神戸大学リポジトリ（Kernel）へのリンク

  • Luisa de Vivo, Hirotaka Nagai, Noemi De Wispelaere, Giovanna Maria Spano, William Marshall, Michele Bellesi, Kelsey Marie Nemec, Shannon Sandra Schiereck, Midori Nagai, Giulio Tononi, Chiara Cirelli
    In adolescent and adult brains several molecular, electrophysiological, and ultrastructural measures of synaptic strength are higher after wake than after sleep [1, 2]. These results support the proposal that a core function of sleep is to renormalize the increase in synaptic strength associated with ongoing learning during wake, to reestablish cellular homeostasis and avoid runaway potentiation, synaptic saturation, and memory interference [2, 3]. Before adolescence however, when the brain is still growing and many new synapses are forming, sleep is widely believed to promote synapse formation and growth. To assess the role of sleep on synapses early in life, we studied 2-week-old mouse pups (both sexes) whose brain is still undergoing significant developmental changes, but in which sleep and wake are easy to recognize. In two strains (CD-1, YFP-H) we found that pups spend ~50% of the day asleep and show an immediate increase in total sleep duration after a few hours of enforced wake, indicative of sleep homeostasis. In YFP-H pups we then used serial block-face electron microscopy to examine whether the axon-spine interface (ASI), an ultrastructural marker of synaptic strength, changes between wake and sleep. We found that the ASI of cortical synapses (layer 2, motor cortex) was on average 33.9% smaller after sleep relative to after extended wake and the differences between conditions were consistent with multiplicative scaling. Thus, the need for sleep-dependent synaptic renormalization may apply also to the young, pre-weaned cerebral cortex, at least in the superficial layers of the primary motor area.
    2019年10月, Sleep, 42(11) (11), 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Satoshi Okamura, Hirotaka Nagai, Chisato Numa, Midori Nagai, Ryota Shinohara, Tomoyuki Furuyashiki
    AIMS: Animal studies using various stress models have shown that excessive environmental stress induces depression? and anxiety?like behaviors through inflammatory responses in the brain and periphery. Although the leptomeningeal cells have multiple functions related to inflammatory responses in the brain, whether environmental stress influences the leptomeninges remains unknown. In this study, we aimed to examine phosphorylation of the extracellular signal-regulated kinase (ERK) in the leptomeninges. METHODS: We subjected C57BL/6 male mice to a single episode of social defeat stress and analyzed the expression of phosphorylated ERK in the leptomeninges by immunohistochemistry. RESULTS: Social defeat stress in mice induced phosphorylation of ERK in the leptomeninges, adjacent to vascular endothelial cells and the glia limitans. This ERK phosphorylation was maintained for at least one hour after the stress. CONCLUSIONS: This study shows the effect of environmental stress on the leptomeninges for the first time and paves the way for elucidating its functional role in stress-induced changes in neural functions.
    2019年06月, Neuropsychopharmacology reports, 39(2) (2), 134 - 139, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）
    神戸大学リポジトリ（Kernel）へのリンク

  • Satomi Funahashi, Yasumasa Okazaki, Hirotaka Nagai, Shan Hwu Chew, Kumiko Ogawa, Takeshi Toyoda, Young-Man Cho, Shinya Toyokuni
    Fibroadenoma (FA) is a common mammary fibroepithelial tumor. The tumor size of the FA is increased by estrogen, progesterone, prolactin, and pregnancy, whereas it decreases after menopause. These observations in humans indicate that FA is hormone dependent. In rats, the most common mammary neoplasm is also FA. Expression levels of Twist1, a transcriptional regulator of epithelial-mesenchymal transition, were examined in paraffin-embedded tissue sections of an experimental rat breast model to find physiological alternations coincident with reproductive hormonal changes. Twenty-three Fischer 344/Brown Norway F1 hybrid rats were used as 14- to 16-week-old adolescent rats (n=3), pregnant rats (n=4), and lactating rats (n=6) in addition to rats over 100-weeks-old that exhibited aging (n=3) and FA (n=7). Seventy-six cases of chemically induced breast carcinoma and two cases of FA in Sprague Dawley rats were also examined. Using tissue sections, we observed that Twist1-positive mesenchymal cells were predominantly located in the periductal region in adolescent and pregnant rats and in the terminal duct lobular unit in pregnant and elderly rats. Twist1 was also expressed diffusely in the mesenchymal cells of FA rats. Twist1-positive cancer-associated mesenchymal cells were found more frequently in the invasive components of breast carcinomas than in intraductal components. The expressions of Twist1 in mesenchymal cells were induced by physiological and pathological stimuli, suggesting the biological role of Twist1 in tissue structure. Further study may reveal the role of Twist1 in mesenchymal cells of mammary glands in rats.
    2019年01月, Journal of toxicologic pathology, 32(1) (1), 19 - 26, 英語, 国内誌
    [査読有り]
    研究論文（学術雑誌）

  • Shu Higashida, Hirotaka Nagai, Kazuki Nakayama, Ryota Shinohara, Masayuki Taniguchi, Midori Nagai, Takatoshi Hikida, Satoshi Yawata, Yukio Ago, Shiho Kitaoka, Shuh Narumiya, Tomoyuki Furuyashiki
    Repeated social defeat stress (R-SDS) induces multiple behavioral changes in mice. However, the relationships between these behavioral changes were not fully understood. In the first experiment, to examine how the social avoidance is related to R-SDS-impaired behavioral flexibility, 10-week-old male C57BL/6N mice received R-SDS followed by the social interaction test and the attentional set shifting task. R-SDS impaired attentional set shifting irrespective of the development of social avoidance. In the second experiment, to examine whether R-SDS affects sexual preference and how this behavioral change is related to the social avoidance and R-SDS-heightened anxiety, another group of 10-week-old male C57BL/6N mice were subjected to R-SDS followed by the social interaction test, the female encounter test and the elevated plus maze test. The anxiety was heightened in the defeated mice without social avoidance, but not in those which showed social avoidance. Furthermore, female preference was increased specifically in the defeated mice which showed heightened anxiety, but was not related to the level of social avoidance. Together, these results showed that attentional set shifting is more sensitive to R-SDS than social interaction, and that female preference is affected by R-SDS in association with heightened anxiety rather than the social avoidance.
    Springer Science and Business Media LLC, 2018年07月, Scientific reports, 8(1) (1), 10454 - 10454, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）
    神戸大学リポジトリ（Kernel）へのリンク

  • Sakiko Honjoh, Shuntaro Sasai, Shannon S Schiereck, Hirotaka Nagai, Giulio Tononi, Chiara Cirelli
    The "non-specific" ventromedial thalamic nucleus (VM) has long been considered a candidate for mediating cortical arousal due to its diffuse, superficial projections, but direct evidence was lacking. Here, we show in mice that the activity of VM calbindin1-positive matrix cells is high in wake and REM sleep and low in NREM sleep, and increases before cortical activity at the sleep-to-wake transition. Optogenetic stimulation of VM cells rapidly awoke all mice from NREM sleep and consistently caused EEG activation during slow wave anesthesia, while arousal did not occur from REM sleep. Conversely, chemogenetic inhibition of VM decreased wake duration. Optogenetic activation of the "specific" ventral posteromedial nucleus (VPM) did not cause arousal from either NREM or REM sleep. Thus, matrix cells in VM produce arousal and broad cortical activation during NREM sleep and slow wave anesthesia in a way that accounts for the effects classically attributed to "non-specific" thalamic nuclei.
    Nature Publishing Group, 2018年05月, Nature communications, 9(1) (1), 2100 - 2100, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Luisa de Vivo, Michele Bellesi, Maria Felice Ghilardi, Giulio Tononi, Chiara Cirelli
    Introduction: Sleep-dependent consolidation of motor learning has been extensively studied in humans, but it remains unclear why some, but not all, learned skills benefit from sleep. Aims and Methods: Here, we compared 2 different motor tasks, both requiring the mice to run on an accelerating device. In the rotarod task, mice learn to maintain balance while running on a small rod, while in the complex wheel task, mice run on an accelerating wheel with an irregular rung pattern. Results: In the rotarod task, performance improved to the same extent after sleep or after sleep deprivation (SD). Overall, using 7 different experimental protocols (41 sleep deprived mice, 26 sleeping controls), we found large interindividual differences in the learning and consolidation of the rotarod task, but sleep before/after training did not account for this variability. By contrast, using the complex wheel, we found that sleep after training, relative to SD, led to better performance from the beginning of the retest session, and longer sleep was correlated with greater subsequent performance. As in humans, the effects of sleep showed large interindividual variability and varied between fast and slow learners, with sleep favoring the preservation of learned skills in fast learners and leading to a net offline gain in the performance in slow learners. Using Fos expression as a proxy for neuronal activation, we also found that complex wheel training engaged motor cortex and hippocampus more than the rotarod training. Conclusions: Sleep specifically consolidates a motor skill that requires complex movement sequences and strongly engages both motor cortex and hippocampus.
    OXFORD UNIV PRESS INC, 2017年02月, Sleep, 40(2) (2), 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Kyoko Yamashita, Hirotaka Nagai, Shinya Toyokuni
    Asbestos-induced mesothelioma is a worldwide problem. Parietal mesothelial cells internalize asbestos fibers that traverse the entire lung parenchyma, an action that is linked to mesothelial carcinogenesis. Thus far, vitronectin purified from serum reportedly enhances the internalization of crocidolite by mesothelial cells via integrin αvβ5. To reveal another mechanism by which mesothelial cells endocytose (phagocytose) asbestos, we first evaluated the effects of serum on asbestos uptake, which proved to be nonessential. Thereafter, we undertook a study to identify proteins on the surface of mesothelial cells (MeT5A) that act as receptors for asbestos uptake based on the assumption that receptors bind to asbestos with physical affinity. To this end, we incubated the membrane fraction of MeT5A cells with crocidolite or chrysotile and evaluated the adsorbed proteins using sodium dodecyl sulfate polyacrylamide gel analysis. Next, we extensively identified the proteins using an in-solution or in-gel digestion coupled with mass spectrometry. Among the identified proteins, annexin A2 (ANXA2) and transferrin receptor protein 1 (TFRC) were distinguished because of their high score and presence at the cell surface. Crocidolite uptake by MeT5A cells was significantly decreased by shRNA (short hairpin RNA)-induced knockdown of ANXA2 and direct blockade of cell surface ANXA2 using anti-ANXA2 antibody. In addition, abundant ANXA2 protein was present on the cell membrane of mesothelial cells, particularly facing the somatic cavity. These findings demonstrate that ANXA2 has a role in the mesothelial phagocytosis of crocidolite and may serve as its receptor.
    NATURE PUBLISHING GROUP, 2015年07月, Laboratory investigation; a journal of technical methods and pathology, 95(7) (7), 749 - 64, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Satomi Funahashi, Yasumasa Okazaki, Daiki Ito, Atsushi Asakawa, Hirotaka Nagai, Masafumi Tajima, Shinya Toyokuni
    Asbestos exposure is considered a social burden by causing mesothelioma. Despite the use of synthetic materials, multi-walled carbon nanotubes (MWCNTs) are similar in dimension to asbestos and produce mesothelioma in animals. The role of inflammatory cells in mesothelial carcinogenesis remains unclear. Here, we evaluated the differences in inflammatory cell responses following exposure to these fibrous materials using a luminometer and L-012 (8-amino-5-chloro-7-phenylpyrido[3,4-d]pyridazine-1,4-(2H,3H) dione) to detect reactive oxygen species (ROS). Rat peripheral blood or RAW264.7 cells were used to assess the effects on neutrophils and macrophages, respectively. Crocidolite and amosite induced significant ROS generation by neutrophils with a peak at 10 min, whereas that of chrysotile was ~25% of the crocidolite/amosite response. MWCNTs with different diameters (~15, 50, 115 and 145 nm) and different carcinogenicity did not induce significant ROS in peripheral blood. However, the MWCNTs induced a comparable amount of ROS in RAW264.7 cells to that following asbestos treatment. The peaks for MWCNTs (0.5-1.5 h) were observed earlier than those for asbestos (1-5 h). Apocynin and superoxide dismutase significantly inhibited ROS generation for each fiber, suggesting an involvement of NADPH oxidase and superoxide. Thus, asbestos and MWCNTs induce different oxidative responses in inflammatory cells, indicating the importance of mesothelial cell evaluation for carcinogenesis.
    JOURNAL CLINICAL BIOCHEMISTRY & NUTRITION, 2015年03月, Journal of clinical biochemistry and nutrition, 56(2) (2), 111 - 7, 英語, 国内誌
    [査読有り]
    研究論文（学術雑誌）

  • Jiang, Li, Yamashita, Yoriko, Chew, Shan‐Hwu, Akatsuka, Shinya, Ukai, Shun, Wang, Shenqi, Nagai, Hirotaka, Okazaki, Yasumasa, Takahashi, Takashi, Toyokuni, Shinya
    Due to the formerly widespread use of asbestos, malignant mesothelioma (MM) is increasingly frequent worldwide. MM is classified into epithelioid (EM), sarcomatoid (SM), and biphasic subtypes. SM is less common than EM but is recognized as the most aggressive type of MM, and these patients have a poor prognosis. To identify genes responsible for the aggressiveness of SM, we induced EM and SM in rats, using asbestos, and compared their transcriptomes. Based on the results, we focused on connective tissue growth factor (Ctgf), whose expression was significantly increased in SM compared with EM; EM itself exhibited an increased expression of Ctgf compared with normal mesothelium. Particularly in SM, Ctgf was a major regulator of MM proliferation and invasion through activation of the β-catenin-TCF-LEF signalling pathway, which is autocrine and formed a positive feedback loop via LRP6 as a receptor for secreted Ctgf. High Ctgf expression also played a role in the epithelial-mesenchymal transition in MM. Furthermore, Ctgf is a novel serum biomarker for both early diagnosis and determining the MM prognosis in rats. These data link Ctgf to SM through the LRP6-GSK3β-β-catenin-TCF-Ctgf autocrine axis and suggest Ctgf as a therapeutic target.
    John Wiley & Sons, Ltd. Chichester, UK, 2014年08月, The Journal of pathology, 233(4) (4), 402 - 14, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Rat model demonstrates a high risk of tremolite but a low risk of anthophyllite for mesothelial carcinogenesis.
    Dilinuer Aierken, Yasumasa Okazaki, Shan Hwu Chew, Akihiro Sakai, Yue Wang, Hirotaka Nagai, Nobuaki Misawa, Norihiko Kohyama, Shinya Toyokuni
    Asbestos was abundantly used in industry during the last century. Currently, asbestos confers a heavy social burden due to an increasing number of patients with malignant mesothelioma (MM), which develops after a long incubation period. Many studies have been conducted on the effects of the asbestos types that were most commonly used for commercial applications. However, there are few studies describing the effects of the less common types, or minor asbestos. We performed a rat carcinogenesis study using Japanese tremolite and Afghan anthophyllite. Whereas more than 50% of tremolite fibers had a diameter of < 500 nm, only a small fraction of anthophyllite fibers had a diameter of < 500 nm. We intraperitoneally injected 1 or 10 mg of asbestos into F1 Fischer-344/Brown-Norway rats. In half of the animals, repeated intraperitoneal injections of nitrilotriacetate (NTA), an iron chelator to promote Fenton reaction, were performed to evaluate the potential involvement of iron overload. Tremolite induced MM with a high incidence (96% with 10 mg; 52% with 1 mg), and males were more susceptible than females. Histology was confirmed using immunohistochemistry, and most MMs were characterized as the sarcomatoid or biphasic subtype. Unexpectedly NTA showed an inhibitory effect in females. In contrast, anthophyllite induced no MM after an observation period of 550 days. The results suggest that the carcinogenicity of anthophyllite is weaker than formerly reported, whereas that of tremolite is as potent as major asbestos as compared with our previous data.
    2014年02月, Nagoya journal of medical science, 76(1-2) (1-2), 149 - 60, 英語, 国内誌
    [査読有り]
    研究論文（学術雑誌）

  • Shan Hwu Chew, Yasumasa Okazaki, Hirotaka Nagai, Nobuaki Misawa, Shinya Akatsuka, Kyoko Yamashita, Li Jiang, Yoriko Yamashita, Michio Noguchi, Kiminori Hosoda, Yoshitaka Sekido, Takashi Takahashi, Shinya Toyokuni
    Like many other human cancers, the development of malignant mesothelioma is closely associated with a chronic inflammatory condition. Both macrophages and mesothelial cells play crucial roles in the inflammatory response caused by asbestos exposure. Here, we show that adipocytes can also contribute to asbestos-induced inflammation through dysregulated adipocytokine production. 3T3-L1 preadipocytes were differentiated into mature adipocytes prior to use. These cells took up asbestos fibers (chrysotile, crocidolite and amosite) but were more resistant to asbestos-induced injury than macrophages and mesothelial cells. Expression microarray analysis followed by reverse transcription-PCR revealed that adipocytes respond directly to asbestos exposure with an increased production of proinflammatory adipocytokines [e.g. monocyte chemoattractant protein-1 (MCP-1)], whereas the production of anti-inflammatory adipocytokines (e.g. adiponectin) is suppressed. This was confirmed in epididymal fat pad of mice after intraperitoneal injection of asbestos fibers. Such dysregulated adipocytokine production favors the establishment of a proinflammatory environment. Furthermore, MCP-1 marginally promoted the growth of MeT-5A mesothelial cells and significantly enhanced the wound healing of Y-MESO-8A and Y-MESO-8D human mesothelioma cells. Our results suggest that increased levels of adipocytokines, such as MCP-1, can potentially contribute to the promotion of mesothelial carcinogenesis through the enhanced recruitment of inflammatory cells as well as a direct growth and migration stimulatory effect on mesothelial and mesothelioma cells. Taken together, our findings support a potential cancer-promoting role of adipocytes in asbestos-induced mesothelial carcinogenesis.
    OXFORD UNIV PRESS, 2014年01月, Carcinogenesis, 35(1) (1), 164 - 72, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Yasumasa Okazaki, Shan Hwu Chew, Nobuaki Misawa, Hiroyuki Yasui, Shinya Toyokuni
    Asbestos was used worldwide in huge quantities in the past century. However, because of the unexpected carcinogenicity to mesothelial cells with an extremely long incubation period, many countries face this long-lasting social problem. Mesothelioma is often diagnosed in an advanced stage, for which no effective therapeutic protocols are yet established. We previously reported on the basis of animal experiments that the major pathology in asbestos-induced mesothelial carcinogenesis is local iron overload. Here, we undertook to find an effective strategy to prevent, delay, or lower the malignant potential of mesothelioma during asbestos-induced carcinogenesis. We used intraperitoneal injections of crocidolite to rats. We carried out a 16-week study to seek the maximal-tolerated intervention for iron reduction via oral deferasirox administration or intensive phlebotomy. Splenic iron deposition was significantly decreased with either method, and we found that Perls' iron staining in spleen is a good indicator for iron reduction. We injected a total of 10 mg crocidolite at the age of six weeks, and the preventive measures were via repeated oral administration of 25 to 50 mg/kg/d deferasirox or weekly to bimonthly phlebotomy of 4 to 10 mL/kg/d. The animals were observed until 110 weeks. Deferasirox administration significantly increased the fraction of less malignant epithelioid subtype. Although we found a slightly prolonged survival in deferasirox-treated female rats, larger sample size and refinement of the current protocol are necessary to deduce the cancer-preventive effects of deferasirox. Still, our results suggest deferasirox serves as a potential preventive strategy in people already exposed to asbestos via iron reduction.
    AMER ASSOC CANCER RESEARCH, 2013年11月, Cancer prevention research (Philadelphia, Pa.), 6(11) (11), 1222 - 30, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Yasumasa Okazaki, Shan Hwu Chew, Nobuaki Misawa, Yasumitsu Miyata, Hisanori Shinohara, Shinya Toyokuni
    Multiwalled carbon nanotubes (MWCNTs) have attracted public attention not only for their potential applications in engineering and materials science but also for possible environmental risks. MWCNTs share similar properties with asbestos, a definite human carcinogen causing malignant mesothelioma (MM), in that they are both biopersistent thin fibers with a high aspect ratio. Certain types of MWCNTs do induce MM in animal experiments. Though there are many different types of MWCNTs awaiting use in industry, there is little evidence about what types of MWCNTs present a high risk for MM in vivo. We have previously shown that the diameter of MWCNTs is one of the critical factors for mesothelial injury, which eventually leads to MM. Because of the extensive commercial use of MWCNTs, the properties of MWCNTs that determine carcinogenic activity should be clarified. Here we report that a high dose (10 mg) of a tangled form of pristine MWCNT (with a diameter of 15 nm) did not induce MM after intraperitoneal administration in rats, which were followed for up to 3 years after injection. This observation strengthens our previous finding that the rigidity, diameter, length and surface properties of MWCNTs are important factors in MM induction in vivo.
    2013年09月, Pathology international, 63(9) (9), 457 - 62, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Okazaki, Yasumasa, Nagai, Hirotaka, Chew, Shan H, Li, Jiang, Funahashi, Satomi, Tsujimura, Tohru, Toyokuni, Shinya
    Malignant mesothelioma (MM), which is associated with asbestos exposure, is one of the most deadly tumors in humans. Early MM is concealed in the serosal cavities and lacks specific clinical symptoms. For better treatment, early detection and prognostic markers are necessary. Recently, CD146 and insulin-like growth factor 2 mRNA-binding protein 3 (IMP3) were reported as possible positive markers of MM to distinguish from reactive mesothelia in humans. However, their application on MM of different species and its impact on survival remain to be elucidated. To disclose the utility of these molecules as early detection and prognostic markers of MM, we injected chrysotile or crocidolite intraperitoneally to rats, thus obtaining 26 peritoneal MM and establishing 11 cell lines. We immunostained CD146 and IMP3 using paraffin-embedded tissues and cell blocks and found CD146 and IMP3 expression in 58% (15/26) and 65% (17/26) of MM, respectively, but not in reactive mesothelia. There was no significant difference in both immunostainings for overexpression among the three histological subtypes of MM and the expression of CD146 and IMP3 was proportionally associated. Furthermore, the overexpression of CD146 and/or IMP3 was proportionally correlated with shortened survival. These results suggest that CD146 and IMP3 are useful diagnostic and prognostic markers of MM.
    WILEY-BLACKWELL, 2013年08月, Cancer science, 104(8) (8), 989 - 95, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Kyoko Yamashita, Hirotaka Nagai, Yuji Kondo, Nobuaki Misawa, Shinya Toyokuni
    Exposure to asbestos fibers increases the risk of mesothelioma in humans. One hypothetical carcinogenic mechanism is that asbestos fibers may directly induce mutations in mesothelial cells. Although the uptake of asbestos fibers by mesothelial cells is recognized, methods for the quantification of the uptake have not been well established. In the present study, we evaluated two distinct methods, using crocidolite fibers and MeT5A mesothelial cells. One method is histological evaluation using the cell-block technique, which allows for the direct cross-sectional observation of cells and fibers. We found the bright field observation with ×1000 magnification (oil-immersion) of the sample with Kernechtrot staining was most suitable for this purpose. The other method is flow cytometric analysis, which permits the evaluation of a much larger number of cells. We observed that the side scatter (SSC) increased with the intracellular fibers, and that the "mean SSC ratio (treated/control)" was useful for quantification. We could collect the cells with abundant internalized crocidolite fibers by sorting. Results of the two methodologies were correlated well in the experiments. The quantities of internalized fibers increased with incubation time and loaded dosage, but they were inversely associated with cellular density in culture.
    JOURNAL CLINICAL BIOCHEMISTRY & NUTRITION, 2013年07月, Journal of clinical biochemistry and nutrition, 53(1) (1), 27 - 35, 英語, 国内誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Shan Hwu Chew, Yasumasa Okazaki, Satomi Funahashi, Takashi Namba, Takuya Kato, Atsushi Enomoto, Li Jiang, Shinya Akatsuka, Shinya Toyokuni
    Mesothelial cells, which have diverse roles in physiology and pathology, constitute the mesothelium along with connective tissue and the basement membrane; the mesothelium serves to shield the somatic cavities. After mesothelial injury, mesothelial cells undergo tissue recovery. However, the mechanism of mesothelial regeneration remains poorly understood. In this study, we used confocal time-lapse microscopy to demonstrate that transformed mesothelial cells (MeT5A) and mouse peritoneal mesothelial cells can randomly migrate between cells in cell culture and in ex vivo tissue culture, respectively. Moreover, peritoneal mesothelial cells changed their morphology from a flattened shape to a cuboidal one prior to the migration. Conversely, MDCKII epithelial cells forming tight cell-cell contacts with one another do not alter the arrangement of adjacent cells during movement. Our evidence complements the current hypotheses of mesothelial regeneration and suggests that certain types of differentiated mesothelial cells undergo morphological changes before initiating migration to repair injured sites.
    NATURE PUBLISHING GROUP, 2013年, Scientific reports, 3, 1144 - 1144, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Jiang, Li, Akatsuka, Shinya, Nagai, Hirotaka, Chew, Shan‐Hwu, Ohara, Hiroki, Okazaki, Yasumasa, Yamashita, Yoriko, Yoshikawa, Yutaka, Yasui, Hiroyuki, Ikuta, Katsuya
    Exposure to asbestos is a risk for malignant mesothelioma (MM) in humans. Among the commercially used types of asbestos (chrysotile, crocidolite, and amosite), the carcinogenicity of chrysotile is not fully appreciated. Here, we show that all three asbestos types similarly induced MM in the rat peritoneal cavity and that chrysotile caused the earliest mesothelioma development with a high fraction of sarcomatoid histology. The pathogenesis of chrysotile-induced mesothelial carcinogenesis was closely associated with iron overload: repeated administration of an iron chelator, nitrilotriacetic acid, which promotes the Fenton reaction, significantly reduced the period required for carcinogenesis; massive iron deposition was found in the peritoneal organs with high serum ferritin; and homozygous deletion of the CDKN2A/2B/ARF tumour suppressor genes, the most frequent genomic alteration in human MM and in iron-induced rodent carcinogenesis, was observed in 92.6% of the cases studied with array-based comparative genomic hybridization. The induced rat MM cells revealed high expression of mesoderm-specific transcription factors, Dlx5 and Hand1, and showed an iron regulatory profile of active iron uptake and utilization. These data indicate that chrysotile is a strong carcinogen when exposed to mesothelia, acting through the induction of local iron overload. Therefore, an intervention to remove local excess iron might be a strategy to prevent MM after asbestos exposure.
    John Wiley & Sons, Ltd Chichester, UK, 2012年11月, The Journal of pathology, 228(3) (3), 366 - 77, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Yurika Kubo, Hiroyuki Takenaka, Hirotaka Nagai, Shinya Toyokuni
    The inhalation of asbestos is a risk factor for the development of malignant mesothelioma and lung cancer. Based on the broad surface area of asbestos fibers and their ability to enter the cytoplasm and nuclei of cells, it was hypothesized that proteins that adsorb onto the fiber surface play a role in the cytotoxicity and carcinogenesis of asbestos fibers. However, little is known about which proteins adsorb onto asbestos. Previously, we systematically identified asbestos-interacting proteins and classified them into eight sub-categories: chromatin/nucleotide/RNA-binding proteins, ribosomal proteins, cytoprotective proteins, cytoskeleton-associated proteins, histones and hemoglobin. Here, we report an adsorption profile of proteins for the three commercially used asbestos compounds: chrysotile, crocidolite and amosite. We quantified the amounts of adsorbed proteins by analyzing the silver-stained gels of sodium dodecyl sulfate-polyacrylamide gel electrophoresis with ImageJ software, using the bands for amosite as a standard. We found that histones were most adsorptive to crocidolite and that chromatin-binding proteins were most adsorptive to chrysotile. The results suggest that chrysotile and crocidolite directly interact with chromatin structure through different mechanisms. Furthermore, RNA-binding proteins preferably interacted with chrysotile, suggesting that chrysotile may interfere with transcription and translation. Our results provide novel evidence demonstrating that the specific molecular interactions leading to carcinogenesis are different between chrysotile and crocidolite.
    JOURNAL CLINICAL BIOCHEMISTRY & NUTRITION, 2012年11月, Journal of clinical biochemistry and nutrition, 51(3) (3), 221 - 6, 英語, 国内誌
    [査読有り]
    研究論文（学術雑誌）

  • Shinya Akatsuka, Yoriko Yamashita, Hiroki Ohara, Yu-Ting Liu, Masashi Izumiya, Koichiro Abe, Masako Ochiai, Li Jiang, Hirotaka Nagai, Yasumasa Okazaki, Hideki Murakami, Yoshitaka Sekido, Eri Arai, Yae Kanai, Okio Hino, Takashi Takahashi, Hitoshi Nakagama, Shinya Toyokuni
    Iron overload has been associated with carcinogenesis in humans. Intraperitoneal administration of ferric nitrilotriacetate initiates a Fenton reaction in renal proximal tubules of rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC) after repeated treatments. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of this oxidative stress-induced rat RCCs. The results revealed extensive large-scale genomic alterations with a preference for deletions. Deletions and amplifications were numerous and sometimes fragmented, demonstrating that a Fenton reaction is a cause of such genomic alterations in vivo. Frequency plotting indicated that two of the most commonly altered loci corresponded to a Cdkn2a/2b deletion and a Met amplification. Tumor sizes were proportionally associated with Met expression and/or amplification, and clustering analysis confirmed our results. Furthermore, we developed a procedure to compare whole genomic patterns of the copy number alterations among different species based on chromosomal syntenic relationship. Patterns of the rat RCCs showed the strongest similarity to the human RCCs among five types of human cancers, followed by human malignant mesothelioma, an iron overload-associated cancer. Therefore, an iron-dependent Fenton chemical reaction causes large-scale genomic alterations during carcinogenesis, which may result in distinct genomic profiles. Based on the characteristics of extensive genome alterations in human cancer, our results suggest that this chemical reaction may play a major role during human carcinogenesis.
    PUBLIC LIBRARY SCIENCE, 2012年, PloS one, 7(8) (8), e43403, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Yasumasa Okazaki, Shan Hwu Chew, Nobuaki Misawa, Yoriko Yamashita, Shinya Akatsuka, Toshikazu Ishihara, Kyoko Yamashita, Yutaka Yoshikawa, Hiroyuki Yasui, Li Jiang, Hiroki Ohara, Takashi Takahashi, Gaku Ichihara, Kostas Kostarelos, Yasumitsu Miyata, Hisanori Shinohara, Shinya Toyokuni
    Multiwalled carbon nanotubes (MWCNTs) have the potential for widespread applications in engineering and materials science. However, because of their needle-like shape and high durability, concerns have been raised that MWCNTs may induce asbestos-like pathogenicity. Although recent studies have demonstrated that MWCNTs induce various types of reactivities, the physicochemical features of MWCNTs that determine their cytotoxicity and carcinogenicity in mesothelial cells remain unclear. Here, we showed that the deleterious effects of nonfunctionalized MWCNTs on human mesothelial cells were associated with their diameter-dependent piercing of the cell membrane. Thin MWCNTs (diameter ∼ 50 nm) with high crystallinity showed mesothelial cell membrane piercing and cytotoxicity in vitro and subsequent inflammogenicity and mesotheliomagenicity in vivo. In contrast, thick (diameter ∼ 150 nm) or tangled (diameter ∼ 2-20 nm) MWCNTs were less toxic, inflammogenic, and carcinogenic. Thin and thick MWCNTs similarly affected macrophages. Mesotheliomas induced by MWCNTs shared homozygous deletion of Cdkn2a/2b tumor suppressor genes, similar to mesotheliomas induced by asbestos. Thus, we propose that different degrees of direct mesothelial injury by thin and thick MWCNTs are responsible for the extent of inflammogenicity and carcinogenicity. This work suggests that control of the diameter of MWCNTs could reduce the potential hazard to human health.
    National Acad Sciences, 2011年12月, Proceedings of the National Academy of Sciences of the United States of America, 108(49) (49), E1330-8 - E1338, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Hirotaka Nagai, Toshikazu Ishihara, Wen-Hua Lee, Hiroki Ohara, Yasumasa Okazaki, Katsuya Okawa, Shinya Toyokuni
    Asbestos is a potent carcinogen associated with increased risks of malignant mesothelioma and lung cancer in humans. Although the mechanism of carcinogenesis remains elusive, the physicochemical characteristics of asbestos play a role in the progression of asbestos-induced diseases. Among these characteristics, a high capacity to adsorb and accommodate biomolecules on its abundant surface area has been linked to cellular and genetic toxicity. Several previous studies identified asbestos-interacting proteins. Here, with the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry, we systematically identified proteins from various lysates that adsorbed to the surface of commercially used asbestos and classified them into the following groups: chromatin/nucleotide/RNA-binding proteins, ribosomal proteins, cytoprotective proteins, cytoskeleton-associated proteins, histones and hemoglobin. The surfaces of crocidolite and amosite, two iron-rich types of asbestos, caused more protein scissions and oxidative modifications than that of chrysotile by in situ-generated 4-hydroxy-2-nonenal. In contrast, we confirmed the intense hemolytic activity of chrysotile and found that hemoglobin attached to chrysotile, but not silica, can work as a catalyst to induce oxidative DNA damage. This process generates 8-hydroxy-2'-deoxyguanosine and thus corroborates the involvement of iron in the carcinogenicity of chrysotile. This evidence demonstrates that all three types of asbestos adsorb DNA and specific proteins, providing a niche for oxidative modification via catalytic iron. Therefore, considering the affinity of asbestos for histones/DNA and the internalization of asbestos into mesothelial cells, our results suggest a novel hypothetical mechanism causing genetic alterations during asbestos-induced carcinogenesis.
    WILEY-BLACKWELL, 2011年12月, Cancer science, 102(12) (12), 2118 - 25, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • [Mechanisms of asbestos-induced carcinogenesis].
    Shinya Toyokuni, Li Jiang, Qian Hu, Hirotaka Nagai, Yasumasa Okazaki, Shinya Akatsuka, Yoriko Yamashita
    Several types of fibrous stone called asbestos have been an unexpected cause of human cancer in the history. This form of mineral is considered precious in that they are heat-, friction-, and acid-resistant, are obtained easily from mines, and can be modified to any form with many industrial merits. However, it became evident that the inspiration of asbestos causes a rare cancer called malignant mesothelioma. Because of the long incubation period, the peak year for malignant mesothelioma is expected to be 2025 in Japan. Thus, it is necessary to elucidate the mechanisms of asbestos-induced mesothelial carcinogenesis. In this review, we summarize the cutting edge results of our 5-year project funded by a MEXT grant, in which local iron deposition and the characteristics of mesothelial cells are the key issues.
    2011年05月, Nihon eiseigaku zasshi. Japanese journal of hygiene, 66(3) (3), 562 - 7, 日本語, 国内誌
    研究論文（学術雑誌）

  • Hiroki Ohara, Shinya Akatsuka, Hirotaka Nagai, Yu-Ting Liu, Li Jiang, Yasumasa Okazaki, Yoriko Yamashita, Tomoyuki Nakamura, Shinya Toyokuni
    By using a rat model of renal cell carcinoma (RCC) induced by ferric nitrilotriacetate (Fe-NTA), this study performed genome-wide analysis to identify target genes during carcinogenesis. It screened for genes with decreased expression in RCCs, with simultaneous loss of heterozygosity, eventually to focus on the fibulin-5 (fbln5) gene. Oxidative damage via Fe-NTA markedly increased Fbln5 in the proximal tubules. RCCs presented lower levels of Fbln5. However, a fraction of RCCs presenting pulmonary metastasis revealed significantly higher levels of Fbln5 than those without metastasis, accompanied by immunopositivity of RCC cells and myofibroblast proliferation. Experiments revealed that RCC cell lines showed lower expression of fbln5 than its non-transformed counterpart NRK52E, but that fbln5 transfection to RCC cell lines changed neither proliferation nor migration/invasion. The data suggest that Fbln5 plays a role not only in the tissue repair and remodelling after renal tubular oxidative damage but also in RCC metastasis, presumably as a cytokine.
    INFORMA HEALTHCARE, 2011年02月, Free radical research, 45(2) (2), 211 - 20, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Qian Hu, Shinya Akatsuka, Yoriko Yamashita, Hiroki Ohara, Hirotaka Nagai, Yasumasa Okazaki, Takashi Takahashi, Shinya Toyokuni
    In humans, mesothelioma has been linked to asbestos exposure, especially crocidolite and amosite asbestos, which contain high amounts of iron. Previously, we established a rat model of iron-induced peritoneal mesothelioma with repeated intraperitoneal injections of iron saccharate and an iron chelator, nitrilotriacetate. Here, we analyze these mesotheliomas using array-based comparative genomic hybridization (aCGH) and gene expression profiling by microarray. Mesotheliomas were classified into two distinct types after pathologic evaluation by immunohistochemistry. The major type, epithelioid mesothelioma (EM), originated in the vicinity of tunica vaginalis testis, expanded into the upper peritoneal cavity and exhibited papillary growth and intense podoplanin immunopositivity. The minor type, sarcomatoid mesothelioma (SM), originated from intraperitoneal organs and exhibited prominent invasiveness and lethality. Both mesothelioma types showed male preponderance. SMs revealed massive genomic alterations after aCGH analysis, including homozygous deletion of CDKN2A/2B and amplification of ERBB2 containing region, whereas EMs showed less genomic alterations. Uromodulin was highly expressed in most of the cases. After 4-week treatment, iron deposition in the mesothelia was observed with 8-hydroxy-2'-deoxyguanosine formation. These results not only show two distinct molecular pathways for iron-induced peritoneal mesothelioma, but also support the hypothesis that oxidative stress by iron overload is a major cause of CDKN2A/2B homozygous deletion.
    ELSEVIER SCIENCE INC, 2010年03月, Laboratory investigation; a journal of technical methods and pathology, 90(3) (3), 360 - 73, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

  • Jiang, Li, Nagai, Hirotaka, Ohara, Hiroki, Hara, Shigeo, Tachibana, Mitsuhiro, Hirano, Seishiro, Shinohara, Yasushi, Kohyama, Norihiko, Akatsuka, Shinya, Toyokuni, Shinya
    Respiratory exposure to asbestos has been linked with mesothelioma in humans. However, its carcinogenic mechanism is still unclear. Here we studied the ability of chrysotile, crocidolite and amosite fibers to induce oxidative DNA damage and the modifying factors using four distinct approaches. Electron spin resonance analyses revealed that crocidolite and amosite containing high amounts of iron, but not chrysotile, catalyzed hydroxyl radical generation in the presence of H(2)O(2), which was enhanced by an iron chelator, nitrilotriacetic acid, and suppressed by desferal. Natural iron chelators, such as citrate, adenosine 5'-triphosphate and guanosine 5'-triphosphate, did not inhibit this reaction. Second, we used time-lapse video microscopy to evaluate how cells cope with asbestos fibers. RAW264.7 cells, MeT-5 A and HeLa cells engulfed asbestos fibers, which reached not only cytoplasm but also the nucleus. Third, we utilized supercoiled plasmid DNA to evaluate the ability of each asbestos to induce DNA double strand breaks (DSB). Crocidolite and amosite, but not chrysotile, induced DNA DSB in the presence of iron chelators. We cloned the fragments to identify break sites. DSB occurred preferentially within repeat sequences and between two G:C sequences. Finally, i.p. administration of each asbestos to rats induced not only formation of nuclear 8-hydroxy-2'-deoxyguanosine in the mesothelia, spleen, liver and kidney but also significant iron deposits in the spleen. Together with the established carcinogenicity of i.p. chrysotile, our data suggest that asbestos-associated catalytic iron, whether constitutional or induced by other mechanisms, plays an important role in asbestos-induced carcinogenesis and that chemoprevention may be possible through targeting the catalytic iron.
    Blackwell Publishing Asia Melbourne, Australia, 2008年11月, Cancer science, 99(11) (11), 2142 - 51, 英語, 国際誌
    [査読有り]
    研究論文（学術雑誌）

■ MISC
  • 社会的ストレスはマウスのシナプスプロテオグリカンからのヘパラン硫酸放出に寄与するシナプスとミクログリア接触を誘導する【JST・京大機械翻訳】|||
    NAGAI Midori, NAGAI Hirotaka, NUMA Chisato, NADANAKA Satomi, KAWASHIMA Yusuke, OHNO Nobuhiko, KITAGAWA Hiroshi, FURUYASHIKI Tomoyuki
    2023年, 日本薬理学会年会要旨集(Web), 97th

  • マウスの社会ストレスは前頭前皮質錐体神経細胞の樹状突起消失に先行して細胞内変性を誘導する
    沼知里, 永井裕崇, 永井碧, 山下朋美, 川島祐介, 大野伸彦, 片岡洋祐, 片岡洋祐, 三森(清末)優子, 加藤太朗, 古屋敷智之
    2022年, 日本神経化学会大会抄録集(Web), 65th

  • 沼 知里, 永井 裕崇, 永井 碧, 山下 朋美, 川島 祐介, 大野 伸彦, 片岡 洋祐, 清末 優子, 加藤 太朗, 古屋敷 智之
    Chronic social stress induces neuronal dysfunctions in the medial prefrontal cortex (mPFC) for emotional and cognitive disturbances. However, the subcellular mechanism remains elusive. Here we examined ultrastructural and multi-omics changes in the mPFC in a mouse model of social defeat stress. Acute stress induced dendritic membrane deformation with mitochondrial swelling in mPFC neurons, leading to dendritic atrophy after chronic stress. Synaptic, but not bulk tissue, proteomes in the mPFC differentiated naïve and stressed mice and further uncovered two distinct states in stressed mice. Proteins involved in mitochondrial metabolic functions mostly decreased with chronic stress regardless of the synaptic proteomic state. By contrast, proteins responsible for mitochondrial homeostasis increased in stressed mice with a specific synaptic proteomic state associated with behavioral resilience to chronic stress. These findings suggest that the balance between mitochondrial metabolic dysfunction and its maintenance at mPFC synapses determines stress susceptibility in mice.
    公益社団法人 日本薬理学会, 2022年, 日本薬理学会年会要旨集, 95, 1-SS-13, 日本語

  • 永井 裕崇, 永井 碧, 沼 知里, 山下 朋美, 川島 祐介, 大野 伸彦, 片岡 洋祐, 新間 秀一, 清末 優子, 加藤 太朗, 曽我 朋義, 古屋敷 智之
    Chronic social stress induces emotional and cognitive disturbances and is a risk for mental illness. Reduced neuronal activity in the medial prefrontal cortex (mPFC) underlies these behavioral abnormalities. However, the subcellular origin and process of this neuronal change remain elusive. Here we examined ultrastructural and multi-omics changes in the mPFC with social stress in mice. Social stress caused the loss of dendritic branches with morphological alterations of mitochondria and induced synaptic shrinkage selectively at mitochondria-containing synapses. Social stress deteriorated mitochondrial functions at synapses with altered mitochondrial proteome and central metabolism in the mPFC. Pharmacological manipulation targeting mitochondria attenuated the synaptic shrinkage and depression-related behaviors. These findings show that chronic social stress alters the central metabolism at mPFC synapses, leading to neuronal pathology and depression-related behaviors.
    公益社団法人 日本薬理学会, 2022年, 日本薬理学会年会要旨集, 95, 1-YIA-11, 日本語

  • 山田 留衣, 永井 裕崇, 沼 知里, 堀川 伊和, 永井 碧, 川島 祐介, 古屋敷 智之
    Aging causes cognitive and motivational declines, but the biological basis remains elusive. Here we analyzed distinct behavioral effects of aging in C57BL6N (B6N) and C57BL/6J (B6J) strains. In this study, mice first learned a visual discrimination task to obtain food rewards by responding to the correct one of two visual stimuli. Then, they learned a response direction task of responding to either left or right for food rewards. Attentional set-shifting, behavioral flexibility between the tasks, is known to depend on working memory. Aged B6N mice showed motivational declines in both tasks. By contrast, task motivation was intact in aged B6J mice, but some of them showed a deficit in attentional set-shifting. We also analyzed synaptic proteomes in the medial prefrontal cortex, a brain region crucial for attentional set-shifting. Young and aged B6J mice showed differential expression of many synaptic proteins, some of which increased only in a subset of the aged mice with attentional set-shifting intact. These findings suggest that different biological mechanisms related to genetic and synaptic factors underlie motivation and cognitive declines with aging.
    公益社団法人 日本薬理学会, 2022年, 日本薬理学会年会要旨集, 95, 1-SS-43, 日本語

  • 永井 裕崇, 永井 碧, 沼 知里, 大田 康平, 山下 朋美, 川島 祐介, 大野 伸彦, 片岡 洋祐, 新間 秀一, 清末 優子, 加藤 太朗, 曽我 朋義, 古屋敷 智之
    Excessive or chronic social stress induces emotional and cognitive disturbances and precipitates mental illness. Altered neuronal morphology and functions in the medial prefrontal cortex (mPFC) underlie these behavioral abnormalities. However, its subcellular mechanisms remain elusive. Here we examined ultrastructural and multi-omics changes in the mPFC after social stress in mice. Social stress caused the loss of dendritic branches with morphological alterations of subcellular mitochondria and induced synaptic shrinkage selectively at the synapses with mitochondria. Multi-omics and functional analyses revealed that social stress deteriorated mitochondrial functions with altered mitochondrial proteome at synapses and dysregulated central metabolic pathways in the mPFC. Molecular biological and pharmacological manipulation targeting central metabolism and mitochondria attenuated the synaptic shrinkage and depression-related behaviors. These findings demonstrate that chronic social stress alters the central metabolism at mPFC synapses, leading to neuronal pathology and depression-related behaviors.
    公益社団法人 日本薬理学会, 2022年, 日本薬理学会年会要旨集, 96, 3-B-O06-4, 日本語

  • 質量分析イメージング法を用いた毛髪成分可視化によるストレスモニタリング手法の開発
    植木瞭生, 永井裕崇, 古屋敷智之, 福崎英一郎, 福崎英一郎, 福崎英一郎, 新間秀一, 新間秀一, 新間秀一
    (公社)日本生物工学会, 2021年, 日本生物工学会大会講演要旨集, 73rd, 148 - 148, 日本語

  • ストレスによる脳機能変化を担う多階層プロセスの理解を目指して
    永井裕崇, 古屋敷智之
    2019年11月, 月刊「細胞」, (12) (12), 4 - 8, 日本語
    [招待有り]
    記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）

  • ストレスによる脳組織リモデリング：神経形態変化と炎症反応
    永井裕崇, 古屋敷智之
    2018年12月, CLINICAL NEUROSCIENCE 月刊「臨床神経科学」, 36(12) (12), 1421 - 1424, 日本語
    [招待有り]
    記事・総説・解説・論説等（商業誌、新聞、ウェブメディア）

  • アラキドン酸
    聶 翔, 永井 裕崇, 北岡 志保, 古屋敷 智之
    2018年10月, 脳科学辞典
    [査読有り][招待有り]
    記事・総説・解説・論説等（その他）

  • 中皮細胞によるアスベスト取り込みに関わるタンパクについての解析
    山下享子, 永井裕崇, 豊国伸哉
    2014年, 日本病理学会会誌, 103(1) (1)

  • 中皮細胞によるアスベスト取り込みに関わるタンパク質についての解析
    山下享子, 永井裕崇, 豊国伸哉
    2014年, 臨床フリーラジカル会議, 31st

  • 中皮細胞によるクロシドライト取り込みの定量的評価
    山下享子, 永井裕崇, 豊国伸哉
    2013年, 日本病理学会会誌, 102(1) (1)

  • 脂肪細胞はアディポサイトカインの異常調節でアスベスト暴露に誘導される炎症反応に関与する(Adipocytes contribute to inflammatory response induced by asbestos exposure through dysregulated adipocytokines)
    周 珊瑚, 岡崎 泰昌, 永井 裕崇, 赤塚 慎也, 山下 依子, 蒋 麗, 高橋 隆, 豊國 伸哉
    (一社)日本癌学会, 2012年08月, 日本癌学会総会記事, 71回, 198 - 198, 英語

  • DAPはDMT1(IRE)の発現制御を介して、細胞増殖を調節する(AP (DMT1 Associated Protein) regulates cell proliferation through the regulation of DMT1 (IRE))
    岡崎 泰昌, 永井 裕崇, 舟橋 諭美, 周 珊瑚, 葉 淑彬, 葉 國義, Glass Jonathan, 豊國 伸哉
    (一社)日本癌学会, 2012年08月, 日本癌学会総会記事, 71回, 308 - 308, 英語

  • Hirotaka Nagai, Shinya Toyokuni
    The emergence of nanotechnology represents an important milestone, as it opens the way to a broad spectrum of applications for nanomaterials in the fields of engineering, industry and medicine. One example of nanomaterials that have the potential for widespread use is carbon nanotubes, which have a tubular structure made of graphene sheets. However, there have been concerns that they may pose a potential health risk due to their similarities to asbestos, namely their high biopersistence and needle-like structure. We recently found that despite these similarities, carbon nanotubes and asbestos differ in certain aspects, such as their mechanism of entry into mesothelial cells. In the study, we showed that non-functionalized, multi-walled carbon nanotubes enter mesothelial cells by directly piercing through the cell membrane in a diameter- and rigidity-dependent manner, whereas asbestos mainly enters these cells through the process of endocytosis, which is independent of fiber diameter. In this review, we discuss the key differences, as well as similarities, between asbestos fibers and carbon nanotubes. We also summarize previous reports regarding the mechanism of carbon nanotube entry into non-phagocytic cells. As the entry of fibers into mesothelial cells is a crucial step in mesothelial carcinogenesis, we believe that a comprehensive study on the differences by which carbon nanotubes and asbestos fibers enter into non-phagocytic cells will provide important clues for the safer manufacture of carbon nanotubes through strict regulation on fiber characteristics, such as diameter, surface properties, length and rigidity.
    WILEY-BLACKWELL, 2012年08月, Cancer science, 103(8) (8), 1378 - 90, 英語, 国際誌
    [査読有り]

  • DMT1(divalent metal transporter 1)を介した鉄利用と細胞増殖機構の解析
    岡崎 泰昌, 永井 裕崇, 舟橋 諭美, 周 珊瑚, 葉 淑彬, 葉 國義, Glass Jonathan, 豊國 伸哉
    (一社)日本病理学会, 2012年03月, 日本病理学会会誌, 101(1) (1), 291 - 291, 日本語

  • CD146の過剰発現は、アスベスト誘発ラット悪性腹膜中皮腫の検出に有用である
    舟橋 諭美, 岡崎 泰昌, 永井 裕崇, 蒋 麗, 周 珊瑚, 辻村 亨, 豊國 伸哉
    (一社)日本病理学会, 2012年03月, 日本病理学会会誌, 101(1) (1), 396 - 396, 日本語

  • アスベスト誘発性中皮腫においてctgfの上方制御はβ-カテニン経路と関連する(Up-regulated ctgf is associated with beta-catenin pathway in asbestos-induced mesothelioma)
    蒋 麗, 山下 依子, 赤塚 慎也, 周 珊瑚, 永井 裕崇, 鵜飼 俊, 豊國 伸哉
    (一社)日本病理学会, 2012年03月, 日本病理学会会誌, 101(1) (1), 397 - 397, 英語

  • 鉄化合物誘発ラット腹膜中皮腫において、高悪性度を特徴づけるmicroRNAの発現 機能解析への取組み
    酒井 晃太, 岡崎 泰昌, 永井 裕崇, 胡 茜, 赤塚 慎也, 山下 享子, 山下 依子, 蒋 麗, 舟橋 諭美, 周 珊瑚, 高橋 隆, 豊國 伸哉
    (一社)日本病理学会, 2012年03月, 日本病理学会会誌, 101(1) (1), 435 - 435, 日本語

  • アスベスト誘発ラット悪性中皮腫の悪性度にctgf(connective tissue growth factor)が及ぼす影響について
    鵜飼 俊, 蒋 麗, 周 珊瑚, 赤塚 慎也, 山下 依子, 永井 裕崇, 岡崎 泰昌, 豊國 伸哉
    (一社)日本病理学会, 2012年03月, 日本病理学会会誌, 101(1) (1), 440 - 440, 日本語

  • ラット乳腺線維腺腫の間質細胞はTWIST-1を発現する
    舟橋 諭美, 岡崎 泰昌, 胡 茜, 周 珊瑚, 永井 裕崇, 豊國 伸哉
    日本毒性病理学会, 2012年02月, 日本毒性病理学会講演要旨集, 28回, 87 - 87, 日本語

  • 酸化ストレス誘発腎発癌モデルにおけるlipocalin-2発現の意義(An implication of lipocalin-2 expression in an oxidative stress-induced renal carcinogenesis model)
    赤塚 慎也, 山下 依子, 岡崎 泰昌, 蒋 麗, 永井 裕崇, 高橋 隆, 豊國 伸哉
    (一社)日本癌学会, 2011年09月, 日本癌学会総会記事, 70回, 147 - 148, 英語

  • 鉄化合物による高悪性度肉腫型中皮腫の表現型に関与するmicroRNAの検出と機能解析(Detection and functional analyses of microRNA in high-grade phenotype of iron-induced sarcomatoid mesothelioma in rats)
    岡崎 泰昌, 胡 茜, 赤塚 慎也, 山下 享子, 舟橋 諭美, 山下 依子, 蒋 麗, 大原 浩貴, 周 珊瑚, 永井 裕崇, 高橋 隆, 豊國 伸哉
    (一社)日本癌学会, 2011年09月, 日本癌学会総会記事, 70回, 266 - 267, 英語

  • 異所性子宮間質細胞の卵巣明細胞腺癌発生における役割について(The role of ectopic endometrial stromal cells in endometriosis-associated ovarian clear cell adenocarcinoma)
    山下 依子, 小林 浩晴, 赤塚 慎也, 永井 裕崇, 吉川 史隆, 高橋 隆, 豊國 伸哉
    (一社)日本癌学会, 2011年09月, 日本癌学会総会記事, 70回, 278 - 279, 英語

  • 悪性中皮腫の発生における脂肪組織の役割(Potential involvement of adipose tissue in malignant mesothelioma development)
    周 珊瑚, 岡崎 泰昌, 永井 裕崇, 山下 依子, 赤塚 慎也, 蒋 麗, 豊國 伸哉
    (一社)日本癌学会, 2011年09月, 日本癌学会総会記事, 70回, 485 - 485, 英語

  • microRNA 199/214は鉄誘発高悪性度ラット中皮腫の特徴である
    岡崎 泰昌, 胡 茜, 赤塚 慎也, 山下 享子, 山下 依子, 蒋 麗, 大原 浩貴, 永井 裕崇, 高橋 隆, 豊國 伸哉
    (一社)日本病理学会, 2011年03月, 日本病理学会会誌, 100(1) (1), 311 - 311, 日本語

  • 酸化ストレス誘発ラット腎癌は高度な染色体不安定性を示す
    赤塚 慎也, 山下 依子, 岡崎 泰昌, 蒋 麗, 永井 裕崇, 新井 恵吏, 金井 弥栄, 豊國 伸哉
    (一社)日本病理学会, 2011年03月, 日本病理学会会誌, 100(1) (1), 422 - 422, 日本語

  • アスベストは表面に特異的なタンパクを結合する
    永井 裕崇, 石原 敏和, 李 文華, 大原 浩貴, 岡崎 泰昌, 大川 克也, 豊國 伸哉
    (一社)日本病理学会, 2011年03月, 日本病理学会会誌, 100(1) (1), 423 - 423, 日本語

  • アスベスト誘発中皮腫の病理解明と予防法の開発
    蒋 麗, 山下 依子, 赤塚 慎也, 永井 裕崇, 多田 正幸, 岡崎 泰昌, 豊國 伸哉
    (一社)日本病理学会, 2011年03月, 日本病理学会会誌, 100(1) (1), 423 - 423, 英語

  • アスベスト誘発ラット悪性中皮腫の悪性度とCTGF(Connective Tissue Growth Factor)の関連について
    多田 正幸, 蒋 麗, 周 珊瑚, 山下 依子, 永井 裕崇, 岡崎 泰昌, 赤塚 慎也, 豊國 伸哉
    (一社)日本病理学会, 2011年03月, 日本病理学会会誌, 100(1) (1), 495 - 495, 日本語

  • アスベスト貪食後に中皮細胞が分泌するタンパク質の機能解析
    有竹 典, 永井 裕崇, 加藤 琢哉, 近藤 裕史, 山下 依子, 豊國 伸哉
    (一社)日本病理学会, 2011年03月, 日本病理学会会誌, 100(1) (1), 495 - 495, 日本語

  • 豊國伸哉, 蒋麗, 胡茜, 永井裕崇, 岡崎泰昌, 赤塚慎也, 山下依子
    Several types of fibrous stone called asbestos have been an unexpected cause of human cancer in the history. This form of mineral is considered precious in that they are heat-, friction-, and acid-resistant, are obtained easily from mines, and can be modified to any form with many industrial merits. However, it became evident that the inspiration of asbestos causes a rare cancer called malignant mesothelioma. Because of the long incubation period, the peak year for malignant mesothelioma is expected to be 2025 in Japan. Thus, it is necessary to elucidate the mechanisms of asbestos-induced mesothelial carcinogenesis. In this review, we summarize the cutting edge results of our 5-year project funded by a MEXT grant, in which local iron deposition and the characteristics of mesothelial cells are the key issues.
    日本衛生学会, 2011年, 日本衛生学雑誌, 66(3) (3), 562 - 567, 日本語
    [査読有り]
    記事・総説・解説・論説等（学術雑誌）

  • Nagai, Hirotaka, Toyokunia, Shinya
    The Materials Research Society of Japan, 2011年, Transactions of the Materials Research Society of Japan, 36(1) (1), 47 - 50, 英語
    [査読有り]
    記事・総説・解説・論説等（学術雑誌）

  • 豊國 伸哉, 蒋 麗, 永井 裕崇, 岡崎 泰昌, 赤塚 慎也, 山下 依子
    (NPO)日本肺癌学会, 2010年10月, 肺癌, 50(5) (5), 559 - 559, 日本語

  • Hirotaka Nagai, Shinya Toyokuni
    Nano-sized durable fibrous materials such as carbon nanotubes have raised safety concerns similar to those raised by asbestos. However, the mechanism by which particulates with ultrafine structure cause inflammation and ultimately cancer (e.g. malignant mesothelioma and lung cancer) is largely unknown. This is partially because the particulates are not uniform and they vary in a plethora of factors. Such variances include length, diameter, surface area, density, shape, contaminant metals (including iron) and crystallinity. Each of these factors is involved in particulate toxicity both in vitro and in vivo. Thus, the elicited biological responses are incredibly complicated. Various kinds of fibers were evaluated with different cells, animals and methods. The aim of this review is to concisely summarize previous reports from the standpoint that activation of macrophages and mesothelial injury are the two major mechanisms of inflammation and possibly cancer. Importantly, these two mechanisms appear to be interacting with each other. However, there is a lack of data on the interplay of macrophage and mesothelium especially in vivo. Since fibrous nanomaterials present potential applications in various fields, it is necessary to develop standard evaluation methods to minimize risks for human health.
    ELSEVIER SCIENCE INC, 2010年10月01日, Archives of biochemistry and biophysics, 502(1) (1), 1 - 7, 英語, 国際誌
    [査読有り]

  • アスベストに誘発されたラット悪性中皮腫の病理学の解析(Mechanism implicated in asbestos-induced malignant mesothelioma in rat)
    蒋 麗, 山下 依子, 赤塚 慎也, 岡崎 泰昌, 永井 裕崇, 豊國 伸哉
    (一社)日本癌学会, 2010年08月, 日本癌学会総会記事, 69回, 87 - 87, 英語

  • ヒト中皮細胞はアスベスト貪食後に様々なタンパクを分泌する(Human mesothelial cells secretes various proteins upon phagocytosis of asbestos)
    永井 裕崇, 加藤 琢哉, 山下 依子, 豊國 伸哉
    (一社)日本癌学会, 2010年08月, 日本癌学会総会記事, 69回, 140 - 140, 英語

  • CDKN2A/2Bのホモ欠損は鉄誘発高悪性度ラット中皮腫の特徴である(Homozygous deletion of CDKN2A/2B is a hallmark of iron-induced hieh-grade rat mesothelioma)
    岡崎 泰昌, 胡 茜, 赤塚 慎也, 山下 依子, 大原 浩貴, 蒋 麗, 永井 裕崇, 高橋 隆, 豊國 伸哉
    (一社)日本癌学会, 2010年08月, 日本癌学会総会記事, 69回, 218 - 218, 英語

  • がんの予防・化学予防 アスベスト誘発中皮腫発がん機構の解明に基づく予防の試み(Cancer prevention and chemoprevention Elucidation of asbestos-induced mesothelial carcinogenesis and its application to prevention)
    豊國 伸哉, 蒋 麗, 永井 裕崇, 岡崎 泰昌, 赤塚 慎也, 山下 依子
    (一社)日本癌学会, 2010年08月, 日本癌学会総会記事, 69回, 233 - 233, 英語

  • アスベスト誘発中皮腫発がんには酸化ストレスが関与する
    豊國 伸哉, 蒋 麗, 胡 茜, 永井 裕崇, 赤塚 慎也, 岡崎 泰昌, 山下 依子
    (一社)日本病理学会, 2010年03月, 日本病理学会会誌, 99(1) (1), 207 - 207, 日本語

  • CDKN2A/2Bのホモ欠損は鉄誘発高悪性度ラット中皮腫の特徴である
    岡崎 泰昌, 胡 茜, 赤塚 慎也, 山下 依子, 大原 浩貴, 永井 裕崇, 高橋 隆, 豊國 伸哉
    (一社)日本病理学会, 2010年03月, 日本病理学会会誌, 99(1) (1), 298 - 298, 日本語

  • アスベストは表面に特異的なタンパクを結合する
    永井 裕崇, 李 文華, 大原 浩貴, 大川 克也, 豊國 伸哉
    (一社)日本病理学会, 2010年03月, 日本病理学会会誌, 99(1) (1), 298 - 298, 日本語

  • ヒト中皮細胞はアスベストを貪食した後に様々なタンパク質を産生する
    伊藤 裕紀, 永井 裕崇, 加藤 琢哉, 山下 依子, 豊國 伸哉
    (一社)日本病理学会, 2010年03月, 日本病理学会会誌, 99(1) (1), 368 - 368, 日本語

  • Shinya Toyokuni, Li Jiang, Hirotaka Nagai, Hiroki Ohara, Yasumasa Okazaki, Shinya Akatsuka, Yoriko Yamashita
    ELSEVIER SCIENCE INC, 2010年, FREE RADICAL BIOLOGY AND MEDICINE, 49, S72 - S72, 英語
    研究発表ペーパー・要旨（国際会議）

  • 豊國 伸哉, 蒋 麗, 永井 裕崇, 石原 敏和, 赤塚 慎也, 山下 依子
    (NPO)日本肺癌学会, 2009年10月, 肺癌, 49(5) (5), 584 - 584, 日本語

  • 蒋 麗, 永井 裕崇, 赤塚 慎也, 大原 浩貴, 山下 依子, 豊國 伸哉
    (NPO)日本肺癌学会, 2009年10月, 肺癌, 49(5) (5), 759 - 759, 英語

  • 鉄の腹腔内反復投与によるラット中皮腫モデルにおけるマイクロアレイ解析(Microarray analysis of mesothelioma induced by intraperitoneal injections of ferric saccharate in rats)
    胡 茜, 赤塚 慎也, 大原 浩貴, 永井 裕崇, 山下 依子, 高橋 隆, 豊國 伸哉
    (一社)日本癌学会, 2009年08月, 日本癌学会総会記事, 68回, 117 - 117, 英語

  • アスベスト誘発中皮腫発がん機構の解明(Novel mechanism implicated in asbestos-induced malignant mesothelioma)
    蒋 麗, 永井 裕崇, 赤塚 慎也, 大原 浩貴, 山下 依子, 豊國 伸哉
    (一社)日本癌学会, 2009年08月, 日本癌学会総会記事, 68回, 117 - 117, 英語

  • 酸化ストレス誘発腎発癌における標的遺伝子の解析(Analysis of a target gene in oxidative stress-induced renal carcinogenesis)
    大原 浩貴, 劉 玉テイ, 永井 裕崇, 赤塚 慎也, 中邨 智之, 豊國 伸哉
    (一社)日本癌学会, 2009年08月, 日本癌学会総会記事, 68回, 135 - 135, 英語

  • 卵巣明細胞腺癌のアレイCGH解析
    山下 依子, 石原 敏和, 永井 裕崇, 中村 栄男, 豊國 伸哉
    (一社)日本病理学会, 2009年03月, 日本病理学会会誌, 98(1) (1), 379 - 379, 日本語

  • アスベスト繊維は非貪食細胞である中皮細胞株に積極的に取り込まれる
    永井 裕崇, 豊國 伸哉
    (一社)日本病理学会, 2009年03月, 日本病理学会会誌, 98(1) (1), 399 - 399, 日本語

  • アスベスト発癌における鉄の関与
    石原 敏和, 永井 裕崇, 蒋 麗, 大川 克也, 豊國 伸哉
    (一社)日本病理学会, 2009年03月, 日本病理学会会誌, 98(1) (1), 399 - 399, 日本語

  • 豊國 伸哉, 蒋 麗, 吉原 美奈子, 永井 裕崇, 赤塚 慎也
    (NPO)日本肺癌学会, 2008年10月, 肺癌, 48(5) (5), 469 - 469, 日本語

  • 永井 裕崇, 李 文華, 蒋 麗, 鐘 毅, 大原 浩貴, 大川 克也, 豊國 伸哉
    (NPO)日本肺癌学会, 2008年10月, 肺癌, 48(5) (5), 655 - 655, 日本語

  • アスベスト誘発発癌機構とその予防戦略(Asbestos-induced carcinogenesis and its prevention strategy)
    豊國 伸哉, 蒋 麗, 永井 裕崇, 赤塚 慎也
    (一社)日本癌学会, 2008年09月, 日本癌学会総会記事, 67回, 106 - 106, 英語

  • アスベスト表面に特異的蛋白質が結合する(Asbestos surface adsorbs specific kinds of proteins)
    永井 裕崇, 李 文華, 鐘 毅, 大原 浩貴, 大川 克也, 豊國 伸哉
    (一社)日本癌学会, 2008年09月, 日本癌学会総会記事, 67回, 116 - 116, 英語

  • 酸化ストレス誘発腎発癌における標的遺伝子の解析(Analysis of a target gene in oxidative stress-inducued renal carcinogenesis)
    大原 浩貴, 劉 玉テイ, 胡 茜, 永井 裕崇, 赤塚 慎也, 中邨 智之, 豊國 伸哉
    (一社)日本癌学会, 2008年09月, 日本癌学会総会記事, 67回, 143 - 143, 英語

  • アスベスト結合蛋白質の解析
    永井 裕崇, 李 文華, 鐘 毅, 大原 浩貴, 大川 克也, 豊國 伸哉
    (一社)日本病理学会, 2008年03月, 日本病理学会会誌, 97(1) (1), 392 - 392, 日本語

■ 書籍等出版物
  • ラング・デール薬理学 原書8版
    永井裕崇, 古屋敷智之
    共訳, 第14章ノルアドレナリン作動性神経伝達, 丸善出版／エルゼビア・ジャパン, 2018年12月

  • ナノカーボンの応用と実用化－フラーレン、ナノチューブ、グラフェンを中心に－
    永井裕崇, 豊國伸哉
    共著, ナノカーボンの細胞毒性・発癌性, シーエムシー出版, 2011年08月

■ 講演・口頭発表等
  • Subcellular mechanisms of social stress
    Hirotaka Nagai, Tomoyuki Furuyashiki
    第94回日本薬理学会年会, 2021年03月
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • 三次元電子顕微鏡法
    永井裕崇
    文部科学省新学術領域研究「マルチスケール精神病態の構成的理解」第3回若手育成セミナー「神経回路の可視化・操作・モデリングのための最先端技術」, 2020年12月
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • Social stress-induced ultrastructural alterations of prefrontal neurons in mice
    永井 裕崇, 古屋敷 智之
    第50回日本神経精神薬理学会年会、第42回日本生物学的精神医学会年会、第4回日本精神薬学会総会・学術集会 合同年会, 2020年08月
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • Analysis of ultrastructural alterations in the mouse medial prefrontal cortex toward the understanding of pathophysiology of social stress-induced depressive-like behaviors
    永井 裕崇, 古屋敷 智之
    第125回日本解剖学会全国学術集会, 2020年03月
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • 研究への情熱はどこからくるか
    永井裕崇
    第30回日本医学会総会2019中部, 2019年04月
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • 社会ストレスによる脳組織の超微細細胞生物学的変化の解析
    永井 裕崇, 古屋敷 智之
    第124回日本解剖学会全国学術集会, 2019年03月
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • マウスの社会挫折ストレスにより誘導される情動変容の多面的解析：社会忌避と不安亢進の解離
    永井 裕崇, 東田 崇, 中山 和紀, 篠原 亮太, 谷口 将之, 永井 碧, 疋田 貴俊, 矢和多 智, 吾郷 由希夫, 北岡 志保, 成宮 周, 古屋敷 智之
    第92回日本薬理学会年会, 2019年03月, 日本語, 大阪, 国内会議
    ポスター発表

  • 断眠ストレスや社会ストレスによる脳組織の超微細な細胞生物学的変化の解析
    永井 裕崇, 古屋敷 智之
    次世代脳プロジェクト冬のシンポジウム2018, 2018年12月, 日本語, 東京, 国内会議
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

  • 断眠ストレスや社会ストレスによる脳組織の超微細な細胞生物学的変化の解析
    永井 裕崇
    第134回日本薬理学会近畿部会, 2018年11月, 日本語, 神戸, 国内会議
    口頭発表（一般）

  • 社会ストレスによる脳組織の超微細な細胞生物学的変化の解析との機序・役割の解明
    永井 裕崇, 古屋敷 智之
    成人病の病因・病態の解明に関する研究助成（TMFC）第24 回研究発表会, 2018年07月, 日本語, 大阪, 国内会議
    ポスター発表

  • Sleep Consolidates Motor Learning of Complex Movement Sequences in Mice
    Hirotaka Nagai, Luisa de Vivo, Michele Bellesi, Maria Felice Ghilardi, Giulio Tononi, Chiara Tononi
    第18回国際基礎臨床薬理学会, 2018年07月, 英語, Kyoto, 国際会議
    ポスター発表

  • マウスの社会挫折ストレスにより誘導される情動変容の多面的解析：社会忌避と不安亢進の解離
    永井 裕崇, 東田 崇, 中山 和紀, 篠原 亮太, 谷口 将之, 永井 碧, 疋田 貴俊, 矢和多 智, 吾郷 由希夫, 北岡 志保, 成宮 周, 古屋敷 智之
    第133回日本薬理学会近畿部会, 2018年06月, 日本語, 広島, 国内会議
    口頭発表（一般）

  • 三次元電顕 (SBF-SEM) で拓く樹状突起スパインの可塑性研究
    永井裕崇
    第123回日本解剖学会総会・全国学術集会, 2018年03月, 日本語, 日本解剖学会, 東京都, 国内会議
    [招待有り]
    シンポジウム・ワークショップパネル（指名）

■ 所属学協会
  • 日本薬理学会

  • 日本神経科学学会

  • 日本解剖学会

  • 日本精神神経薬理学会

■ 共同研究・競争的資金等の研究課題
  • 社会ストレスによる樹状突起委縮を担う分子機序の解明とその制御法の確立
    永井 裕崇
    日本学術振興会, 科学研究費助成事業 基盤研究(C), 基盤研究(C), 神戸大学, 2020年04月01日 - 2023年03月31日
    社会や環境より受ける過度のストレスは内側前頭前皮質神経細胞の形態的萎縮を組織学的基盤とした認知情動変容を招く。しかし、樹状突起やシナプス構造の萎縮を担う分子細胞生物学的な機序は殆ど分かっていない。本研究では、マウスうつ病モデルである社会挫折ストレスモデルを用いて樹状突起やシナプス構造の萎縮を導く機序を解明することを目的とする。今年度は、樹状突起やシナプス形態変化と関連する細胞内構造変化を明らかにするために三次元電子顕微鏡及び超解像イメージングを用いストレス後の前頭前皮質を観察した。その結果、慢性ストレス後に樹状突起分枝の欠失とミトコンドリアの過剰分裂型形態変化が生じることを見出した。また、ストレスによりミトコンドリアを有するシナプス特異的に構造退縮が生じること、さらにシナプス分画のミトコンドリア特異的に機能低下が生じることを見出した。これらの知見は、ストレスによりシナプスや樹状突起のミトコンドリアが変容し、神経細胞の形態的萎縮を招くことを示唆する。ミトコンドリアは中央代謝系の中心的役割を担う。そのためプロテオミクス解析に中央代謝系分子を網羅的に定量解析し、ストレスにより発現変動を示す分子群を同定した。さらにそのうちの一つについて発現抑制を行うことにより情動変容を抑制できることを見出しつつある。今後は同分子並びに抽出されたその他の候補分子について薬理学的・分子生物学的な操作を実施し、神経細胞の形態的萎縮を担う分子機序、並びに認知情動変容を生じる分子機序を明らかにする。

  • 社会ストレスによる神経形態変化を導く神経グリア相互作用の超微細細胞生物学的解明
    永井 裕崇
    日本学術振興会, 科学研究費助成事業 若手研究, 若手研究, 神戸大学, 2018年04月01日 - 2021年03月31日
    社会や環境より受けるストレスは抑うつや不安亢進など情動変容を誘発し、精神疾患のリスクとなる。マウスの社会挫折ストレスモデルにおいては前頭前皮質神経細胞の樹状突起萎縮やスパインの喪失などの萎縮性変化が情動変容に重要であることが示唆されてきており、その機序としてミクログリア活性化に代表される脳内炎症が重要であることが知られる。しかし、ストレスにより生じるミクログリアと神経細胞の直接的相互作用については殆ど知られていない。 本研究においてはストレス後の神経とミクログリアの接触に焦点を当て、その相互作用を明らかにすることを目的とする。 その目的のため、あらゆる細胞と細胞内小器官の可視化を可能とする三次元電子顕微鏡を用い、ストレス後の脳組織におけるミクログリアと神経細胞の三次元的再構築を実施した。その結果、急性の社会ストレス後にはミクログリアが軸索を取り囲む現象が亢進すること、一方で慢性の社会ストレス後にはその亢進が消失することを明らかにした。また、ミクログリアにより完全に貪食された神経構成要素の量はストレスの量や経過時間と関連しなかった。急性ストレスが情動変容よりもストレス抵抗性の増強を導くという先行研究を踏まえると、これらの知見は亢進した軸索－ミクログリア相互作用が神経活動を制御することによりストレス抵抗性を増強する可能性を示唆する。これらの軸索とミクログリアの相互作用界面を担う分子を明らかにし、その役割を調べる今後の研究が必要である。

  • アスベスト誘発発癌機構の解明とその予防
    永井 裕崇
    日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 特別研究員奨励費, 京都大学, 2009年 - 2011年
    多層カーボンナノチューブ(以下、NT)はアスベスト繊維と類似の物理化学的性質を持っため、中皮腫を引き起こす可能性について社会的懸念がある。今回、NTの毒性・発がん性を決める因子を評価するため、5種類のNTと3種類のアスベストを用いて中皮細胞に投与したところ、アスベストは細胞に効率良く取り込まれたが、NTは殆ど取り込まれなかった。NTによる中皮細胞毒性は直径と逆相関であり、さらに透過型電子顕微鏡を用いて観察すると細いNT(~50nm)の方が太いNT(~150nm)よりも中皮細胞の細胞膜や核を貫通し易い事が明らかとなった。一方、アスベストの直径はどのNTよりも大きかったが、膜構造に囲まれた状態で細胞内に存在していた。NTは膜構造に囲まれておらず、NTとアスベストは異なる機構で細胞に入る事が示唆された。NTをラットの腹腔内に投与すると、細いNTは太いNTと比べて、強い炎症を惹起し、中皮腫発生も早く、高率であった。NTをマクロファージに投与し、毒性やサイトカイン産生能を調べたが、直径の異なるNT間に差異は認められなかった。従って、炎症惹起性や発がん性について、中皮細胞傷害性が強く関与している事が示唆された。直径が小さく、かつ凝集塊をつくるようなNTは細胞に入らず、発がん性も最も低かったことから、中皮細胞傷害には直径が小さい事と剛性・直線性が高いことが重要であることと考えられた。以上の知見は、繊維状物質の発がん機構解明に寄与することが大きいだけでなく、社会的意義の高いものであると考えている。また、アスベストの発がん予防についても一定の成果を得られており、現在論文投稿準備中である。

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