Yuyama Kohei
| Institute for the Promotion of Business-Regional Collaboration | Specially Appointed Associate Professor |
Last Updated :2025/12/04
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■Career
Career
- Jun. 2015 - Present
Hokkaido University, Faculty of Advanced Life Science, Associate Professor, Japan - Apr. 2009 - May 2015
Hokkaido University, Faculty of Advanced Life Science, Assistant Professor, Japan - Nov. 2005 - Mar. 2009
National Center for Geriatrics and Gerontology, Department of Alzheimer's Disease, Postdoctoral fellow, Japan - Apr. 2002 - Oct. 2005
Tokyo Metropolitan Institute of Medical Science, Biomembrane Signaling Project, Postdoctral fellow, Japan
Educational Background
■Research activity information
Awards
Papers
- Odor identification score as an alternative method for early identification of amyloidogenesis in Alzheimer's disease.
Yukifusa Igeta, Isao Hemmi, Kohei Yuyama, Yasuyoshi Ouchi
Scientific reports, 14, 1, 4658, 4658, 26 Feb. 2024, [Peer-reviewed], [International Magazine]
English, Scientific journal, A simple screening test to identify the early stages of Alzheimer's disease (AD) is urgently needed. We investigated whether odor identification impairment can be used to differentiate between stages of the A/T/N classification (amyloid, tau, neurodegeneration) in individuals with amnestic mild cognitive impairment or AD and in healthy controls. We collected data from 132 Japanese participants visiting the Toranomon Hospital dementia outpatient clinic. The odor identification scores correlated significantly with major neuropsychological scores, regardless of apolipoprotein E4 status, and with effective cerebrospinal fluid (CSF) biomarkers [amyloid β 42 (Aβ42) and the Aβ42/40 and phosphorylated Tau (p-Tau)/Aβ42 ratios] but not with ineffective biomarkers [Aβ40 and the p-Tau/total Tau ratio]. A weak positive correlation was observed between the corrected odor identification score (adjusted for age, sex, ApoE4 and MMSE), CSF Aβ42, and the Aβ42/40 ratio. The odor identification score demonstrated excellent discriminative power for the amyloidogenesis stage , according to the A/T/N classification, but was unsuitable for differentiating between the p-Tau accumulation and the neurodegeneration stages. After twelve odor species were analyzed, a version of the score comprising only four odors-India ink, wood, curry, and sweaty socks-proved highly effective in identifying AD amyloidogenesis, showing promise for the screening of preclinical AD. - Extracellular vesicle proteome unveils cathepsin B connection to Alzheimer’s disease pathogenesis
Kohei Yuyama, Hui Sun, Risa Fujii, Isao Hemmi, Koji Ueda, Yukifusa Igeta
Brain, Oxford University Press (OUP), 10 Dec. 2023, [Peer-reviewed], [Lead author]
Scientific journal, Abstract
Extracellular vesicles (EVs) are membrane vesicles that are released extracellularly and considered to be implicated in the pathogenesis of neurodegenerative diseases including Alzheimer’s disease. Here, CSF EVs of 16 ATN-classified cases were subjected to quantitative proteome analysis. In these CSF EVs, levels of 11 proteins were significantly altered during the ATN stage transitions (P < 0.05 and fold-change > 2.0). These proteins were thought to be associated with Alzheimer’s disease pathogenesis and represent candidate biomarkers for pathogenic stage classification. Enzyme-linked immunosorbent assay analysis of CSF and plasma EVs revealed altered levels of cathepsin B (CatB) during the ATN transition (seven ATN groups in validation set, n = 136). The CSF and plasma EV CatB levels showed a negative correlation with CSF amyloid-β42 concentrations. This proteomic landscape of CSF EVs in ATN classifications can depict the molecular framework of Alzheimer’s disease progression, and CatB may be considered a promising candidate biomarker and therapeutic target in Alzheimer’s disease amyloid pathology. - Stereochemistry‐activity relationship of ceramide‐induced exosome production to clear amyloid‐β in Alzheimer's disease
Mariam Abdelrasoul, Kohei Yuyama, Mahadeva M. M. Swamy, Yuta Murai, Kenji Monde
Chirality, 35, 9, 577, 585, Wiley, 13 Apr. 2023, [Peer-reviewed]
Scientific journal, Abstract
Stereochemistry has a substantial impact on the biological activity of various drugs. We investigated the role of stereochemistry of ceramides in inducing the production of exosomes, a type of extracellular vesicle, from neuronal cells, with a potential benefit in improving the clearance of amyloid‐β (Aβ), a causal agent of Alzheimer's disease. A stereochemical library of diverse ceramides with different tail lengths was synthesized with the purpose of varying stereochemistry (D‐erythro: DE, D‐threo: DT, L‐erythro: LE, L‐threo: LT) and hydrophobic tail length (C6, C16, C18, C24). The exosome levels were quantified using TIM4‐based exosome enzyme‐linked immunosorbent assay after concentrating the conditioned medium using centrifugal filter devices. The results revealed a pivotal role of stereochemistry in determining the biological activity of ceramide stereoisomers, with the superiority of those based on DE and DT stereochemistry with C16 and C18 tails, which demonstrated significantly higher exosome production, without a significant change in the particle size of the released exosomes. In transwell experiments with Aβ‐expressed neuronal and microglial cells, DE‐ and DT‐ceramides with C16 and C18 tails significantly decreased extracellular Aβ levels. The results reported here are promising in the design of non‐classic therapies for the treatment of Alzheimer's disease. - Immuno-digital invasive cleavage assay for analyzing Alzheimer's amyloid ß-bound extracellular vesicles.
Kohei Yuyama, Hui Sun, Yasuyuki Igarashi, Kenji Monde, Takumi Hirase, Masato Nakayama, Yoichi Makino
Alzheimer's Research & Therapy, 14, 1, 140, 140, 03 Oct. 2022, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, BACKGROUND: The protracted preclinical stage of Alzheimer's disease (AD) provides the opportunity for early intervention to prevent the disease; however, the lack of minimally invasive and easily detectable biomarkers and their measurement technologies remain unresolved. Extracellular vesicles (EVs) are nanosized membrane vesicles released from a variety of cells and play important roles in cell-cell communication. Neuron-derived and ganglioside-enriched EVs capture amyloid-ß protein, a major AD agent, and transport it into glial cells for degradation; this suggests that EVs influence Aß accumulation in the brain. EV heterogeneity, however, requires the use of a highly sensitive technique for measuring specific EVs in biofluid. In this study, immuno-digital invasive cleavage assay (idICA) was developed for quantitating target-intact EVs. METHODS: EVs were captured onto ganglioside GM1-specific cholera toxin B subunit (CTB)-conjugated magnetic beads and detected with a DNA oligonucleotide-labeled Aß antibody. Fluorescence signals for individual EVs were then counted using an invasive cleavage assay (ICA). This idICA examines the Aß-bound and GM1-containing EVs isolated from the culture supernatant of human APP-overexpressing N2a (APP-N2a) cells and APP transgenic mice sera. RESULTS: The idICA quantitatively detected Aß-bound and GM1-containing EVs isolated from culture supernatants of APP-N2a cells and sera of AD model mice. The idICA levels of Aß-associated EVs in blood gradually increased from 3- to 12-month-old mice, corresponding to the progression of Aß accumulations in the brain of AD model mice. CONCLUSIONS: The present findings suggest that peripheral EVs harboring Aß and GM1 reflect Aß burden in mice. The idICA is a valuable tool for easy quantitative detection of EVs as an accessible biomarker for preclinical AD diagnosis. - Evaluation of Plant Ceramide Species-Induced Exosome Release from Neuronal Cells and Exosome Loading Using Deuterium Chemistry
Yuta Murai, Takumi Honda, Kohei Yuyama, Daisuke Mikami, Koichi Eguchi, Yuichi Ukawa, Seigo Usuki, Yasuyuki Igarashi, Kenji Monde
International Journal of Molecular Sciences, 23, 18, 10751, 10751, MDPI AG, 15 Sep. 2022, [Peer-reviewed], [Corresponding author], [International Magazine]
English, Scientific journal, The extracellular accumulation of aggregated amyloid-β (Aβ) in the brain leads to the early pathology of Alzheimer’s disease (AD). The administration of exogenous plant-type ceramides into AD model mice can promote the release of neuronal exosomes, a subtype of extracellular vesicles, that can mediate Aβ clearance. In vitro studies showed that the length of fatty acids in mammalian-type ceramides is crucial for promoting neuronal exosome release. Therefore, investigating the structures of plant ceramides is important for evaluating the potential in releasing exosomes to remove Aβ. In this study, we assessed plant ceramide species with D-erythro-(4E,8Z)-sphingadienine and D-erythro-(8Z)-phytosphingenine as sphingoid bases that differ from mammalian-type species. Some plant ceramides were more effective than mammalian ceramides at stimulating exosome release. In addition, using deuterium chemistry-based lipidomics, most exogenous plant ceramides were confirmed to be derived from exosomes. These results suggest that the ceramide-dependent upregulation of exosome release may promote the release of exogenous ceramides from cells, and plant ceramides with long-chain fatty acids can effectively release neuronal exosomes and prevent AD pathology. - Ceramide Metabolism Regulated by Sphingomyelin Synthase 2 Is Associated with Acquisition of Chemoresistance via Exosomes in Human Leukemia Cells.
Makoto Taniguchi, Shingo Nagaya, Kohei Yuyama, Ai Kotani, Yasuyuki Igarashi, Toshiro Okazaki
International journal of molecular sciences, 23, 18, 13 Sep. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, Ceramide levels controlled by the sphingomyelin (SM) cycle have essential roles in cancer cell fate through the regulation of cell proliferation, death, metastasis, and drug resistance. Recent studies suggest that exosomes confer cancer malignancy. However, the relationship between ceramide metabolism and exosome-mediated cancer malignancy is unclear. In this study, we elucidated the role of ceramide metabolism via the SM cycle in exosomes and drug resistance in human leukemia HL-60 and adriamycin-resistant HL-60/ADR cells. HL-60/ADR cells showed significantly increased exosome production and release compared with parental chemosensitive HL-60 cells. In HL-60/ADR cells, increased SM synthase (SMS) activity reduced ceramide levels, although released exosomes exhibited a high ceramide ratio in both HL-60- and HL-60/ADR-derived exosomes. Overexpression of SMS2 but not SMS1 suppressed intracellular ceramide levels and accelerated exosome production and release in HL-60 cells. Notably, HL-60/ADR exosomes conferred cell proliferation and doxorubicin resistance properties to HL-60 cells. Finally, microRNA analysis in HL-60 and HL-60/ADR cells and exosomes showed that miR-484 elevation in HL-60/ADR cells and exosomes was associated with exosome-mediated cell proliferation. This suggests that intracellular ceramide metabolism by SMS2 regulates exosome production and release, leading to acquisition of drug resistance and enhanced cell proliferation in leukemia cells. - Penta-deuterium-labeled 4E, 8Z-sphingadienine for rapid analysis in sphingolipidomics study.
Yuta Murai, Kohei Yuyama, Daisuke Mikami, Yasuyuki Igarashi, Kenji Monde
Chemistry and physics of lipids, 245, 105202, 105202, 22 Mar. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, The use of deuterium-incorporated bioactive compounds is an efficient method for tracing their metabolic fate and for quantitative analysis by mass spectrometry without complicated HPLC separation even if their amounts are extremely small. Plant sphingolipids and their metabolites, which have C4, 8-olefins on a common backbone as a sphingoid base, show unique and fascinating bioactivities compared to those of sphingolipids in mammals. However, the functional and metabolic mechanisms of exogenous plant sphingolipids have not been elucidated due to the difficulty in distinguishing exogenous sphingolipids from endogenous sphingolipids having the same polarity and same molecular weight by mass spectrometric analysis. Their roles might be elucidated by the use of deuterated probes with original biological and physicochemical properties. In this study, we designed (2S,3R,4E,8Z)-2-aminooctadeca-4,8-diene-17,17,18,18,18-d5-1,3-diol (penta-deuterium-labeled 4E, 8Z-sphingadienine) as a tracer for exogenous metabolic studies. In addition, the sphingadienine was confirmed to be metabolized in HEK293 cells and showed distinct peaks in mass spectrometric analysis. - Konjac Ceramide (kCer)-Mediated Signal Transduction of the Sema3A Pathway Promotes HaCaT Keratinocyte Differentiation
Seigo Usuki, Noriko Tamura, Tomohiro Tamura, Kohei Yuyama, Daisuke Mikami, Katsuyuki Mukai, Yasuyuki Igarashi
Biology, 11, 1, 121, 121, MDPI AG, 12 Jan. 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, Histamines suppress epidermal keratinocyte differentiation. Previously, we reported that konjac ceramide (kCer) suppresses histamine-stimulated cell migration of HaCaT keratinocytes. kCer specifically binds to Nrp1 and does not interact with histamine receptors. The signaling mechanism of kCer in HaCaT cells is also controlled by an intracellular signaling cascade activated by the Sema3A-Nrp1 pathway. In the present study, we demonstrated that kCer treatment induced HaCaT keratinocyte differentiation after migration of immature cells. kCer-induced HaCaT cell differentiation was accompanied by some features of keratinocyte differentiation markers. kCer induced activating phosphorylation of p38MAPK and c-Fos, which increased the protein levels of involucrin that was the latter differentiation marker. In addition, we demonstrated that the effects of both kCer and histamines are regulated by an intracellular mechanism of Rac1 activation/RhoA inhibition downstream of the Sema3A/Nrp1 receptor and histamine/GPCR pathways. In summary, the effects of kCer on cell migration and cell differentiation are regulated by cascade crosstalk between downstream Nrp1 and histamine-GPCR pathways in HaCaT cells. - Intracerebral Transplantation of Mesenchymal Stromal Cell Compounded with Recombinant Peptide Scaffold against Chronic Intracerebral Hemorrhage Model.
Soichiro Takamiya, Masahito Kawabori, Tsukasa Kitahashi, Kentaro Nakamura, Yuki Mizuno, Hironobu Yasui, Yuji Kuge, Aki Tanimori, Yasuyuki Takamatsu, Kohei Yuyama, Hideo Shichinohe, Miki Fujimura
Stem cells international, 2022, 8521922, 8521922, 2022, [Peer-reviewed], [International Magazine]
English, Scientific journal, Background: Due to the lack of effective therapies, stem cell transplantation is an anticipated treatment for chronic intracerebral hemorrhage (ICH), and higher cell survival and engraftment are considered to be the key for recovery. Mesenchymal stromal cells (MSCs) compounded with recombinant human collagen type I scaffolds (CellSaics) have a higher potential for cell survival and engraftment compared with solo-MSCs, and we investigated the validity of intracerebral transplantation of CellSaic in a chronic ICH model. Methods: Rat CellSaics (rCellSaics) were produced by rat bone marrow-derived MSC (rBMSCs). The secretion potential of neurotrophic factors and the cell proliferation rate were compared under oxygen-glucose deprivation (OGD) conditions. rCellSaics, rBMSCs, or saline were transplanted into the hollow cavity of a rat chronic ICH model. Functional and histological analyses were evaluated, and single-photon emission computed tomography for benzodiazepine receptors was performed to monitor sequential changes in neuronal integrity. Furthermore, human CellSaics (hCellSaics) were transplanted into a chronic ICH model in immunodeficient rats. Antibodies neutralizing brain-derived neurotrophic factor (BDNF) were used to elucidate its mode of action. Results: rCellSaics demonstrated a higher secretion potential of trophic factors and showed better cell proliferation in the OGD condition. Animals receiving rCellSaics displayed better neurological recovery, higher intracerebral BDNF, and better cell engraftment; they also showed a tendency for less brain atrophy and higher benzodiazepine receptor preservation. hCellSaics also promoted significant functional recovery, which was reversed by BDNF neutralization. Conclusion: Intracerebral transplantation of CellSaics enabled neurological recovery in a chronic ICH model and may be a good option for clinical application. - Suppressive effect of isomaltodextrin on postprandial blood glucose elevation after ingestion of cooked rice in healthy adults —A randomized, placebo—controlled, double—blind, crossover study—
江口晃一, 向井克之, 湯山耕平, 臼杵靖剛, 栗本成敬, 田中藍子, 勝山(鏡)豊代, 西平 順, 門出健次, 五十嵐 靖之
薬理と治療, 49, 8, 1225, 1239, Aug. 2021, [Peer-reviewed]
Japanese, Scientific journal - Comprehensive Glycomic Approach Reveals Novel Low-Molecular-Weight Blood Group-Specific Glycans in Serum and Cerebrospinal Fluid.
Jun-Ichi Furukawa, Hisatoshi Hanamatsu, Ikuko Yokota, Megumi Hirayama, Tomohiro Ando, Hiroyuki Kobayashi, Shunsuke Ohnishi, Nobuaki Miura, Kazue Okada, Shota Sakai, Kohei Yuyama, Yasuyuki Igarashi, Makoto Ito, Yasuro Shinohara, Naoya Sakamoto
Journal of proteome research, 20, 5, 2812, 2822, 10 Mar. 2021, [Peer-reviewed], [International Magazine]
English, Scientific journal, ABO blood antigens on the human red blood cell membrane as well as different cells in various human tissues have been thoroughly studied. Anti-A and -B antibodies of IgM are present in serum/plasma, but blood group-specific glyco-antigens have not been extensively described. In this study, we performed comprehensive and quantitative serum glycomic analyses of various glycoconjugates and free oligosaccharides in all blood groups. Our comprehensive glycomic approach revealed that blood group-specific antigens in serum/plasma are predominantly present on glycosphingolipids on lipoproteins rather than glycoproteins. Expression of the ABO antigens on glycosphingolipids depends not only on blood type but also on secretor status. Blood group-specific glycans in serum/plasma were classified as type I, whereas those on RBCs had different structures including hexose and hexosamine residues. Analysis of free oligosaccharides revealed that low-molecular-weight blood group-specific glycans, commonly containing lacto-N-difucotetraose, were expressed in serum/plasma according to blood group. Furthermore, comprehensive glycomic analysis in human cerebrospinal fluid showed that many kinds of free oligosaccharides were highly expressed, and low-molecular-weight blood group-specific glycans, which existed in plasma from the same individuals, were present. Our findings provide the first evidence for low-molecular-weight blood group-specific glycans in both serum/plasma and cerebrospinal fluid. - Structure-dependent absorption of atypical sphingoid long-chain bases from digestive tract into lymph
Daisuke Mikami, Shota Sakai, Megumi Nishimukai, Kohei Yuyama, Katsuyuki Mukai, Yasuyuki Igarashi
Lipids in Health and Disease, 20, 1, Springer Science and Business Media LLC, 01 Mar. 2021, [Peer-reviewed]
English, Scientific journal,Abstract
Background
Dietary sphingolipids have various biofunctions, including skin barrier improvement and anti-inflammatory and anti-carcinoma properties. Long-chain bases (LCBs), the essential backbones of sphingolipids, are expected to be important for these bioactivities, and they vary structurally between species. Given these findings, however, the absorption dynamics of each LCB remain unclear.
Methods
In this study, five structurally different LCBs were prepared from glucosylceramides (GlcCers) with LCB 18:2(4E,8Z);2OH and LCB 18:2(4E,8E);2OH moieties derived from konjac tuber (Amorphophallus konjac ), from GlcCers with an LCB 18(9Me):2(4E,8E);2OH moiety derived from Tamogi mushroom (Pleurotus cornucopiae var. citrinopileatus ), and from ceramide 2-aminoethyphosphonate with LCB 18:3(4E,8E,10E);2OH moiety and LCB 18(9Me):3(4E,8E,10E);2OH moiety derived from giant scallop (Mizuhopecten yessoensis ), and their absorption percentages and metabolite levels were analyzed using a lymph-duct-cannulated rat model via liquid chromatography tandem mass spectrometry (LC/MS/MS) with a multistage fragmentation method.
Results
The five orally administered LCBs were absorbed and detected in chyle (lipid-containing lymph) as LCBs and several metabolites including ceramides, hexosylceramides, and sphingomyelins. The absorption percentages of LCBs were 0.10–1.17%, depending on their structure. The absorption percentage of LCB 18:2(4E,8Z);2OH was the highest (1.17%), whereas that of LCB 18:3(4E,8E,10E);2OH was the lowest (0.10%). The amount of sphingomyelin with an LCB 18:2(4E,8Z);2OH moiety in chyle was particularly higher than sphingomyelins with other LCB moieties.
Conclusions
Structural differences among LCBs, particularly geometric isomerism at the C8–C9 position, significantly affected the absorption percentages and ratio of metabolites. This is the first report to elucidate that the absorption and metabolism of sphingolipids are dependent on their LCB structure. These results could be used to develop functional foods that are more readily absorbed.
- Mevalonate pathway-mediated ER homeostasis is required for haploid stability in human somatic cells.
Kan Yaguchi, Kimino Sato, Koya Yoshizawa, Daisuke Mikami, Kohei Yuyama, Yasuyuki Igarashi, Gabor Banhegyi, Eva Margittai, Ryota Uehara
Cell structure and function, 22 Dec. 2020, [Peer-reviewed], [Domestic magazines]
English, Scientific journal, The somatic haploidy is unstable in diplontic animals, but cellular processes determining haploid stability remain elusive. Here, we found that inhibition of mevalonate pathway by pitavastatin, a widely used cholesterol-lowering drug, drastically destabilized the haploid state in HAP1 cells. Interestingly, cholesterol supplementation did not restore haploid stability in pitavastatin-treated cells, and cholesterol inhibitor U18666A did not phenocopy haploid destabilization. These results ruled out the involvement of cholesterol in haploid stability. Besides cholesterol perturbation, pitavastatin induced endoplasmic reticulum (ER) stress, the suppression of which by a chemical chaperon significantly restored haploid stability in pitavastatin-treated cells. Our data demonstrate the involvement of the mevalonate pathway in the stability of the haploid state in human somatic cells through managing ER stress, highlighting a novel link between ploidy and ER homeostatic control. Key words: Haploid, ER stress, Mevalonate, pathway. - Lysosomal-associated transmembrane protein 4B regulates ceramide-induced exosome release.
Kohei Yuyama, Hui Sun, Daisuke Mikami, Tetsuo Mioka, Katsuyuki Mukai, Yasuyuki Igarashi
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 08 Oct. 2020, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, Exosomes are extracellular vesicles that mediate the transport of intracellular molecules, including neurodegenerative agents. Exogenously administrated ceramides have been implicated in the acceleration of exosome production by neurons; however, the molecular machinery involved in this process is unknown. Here, we found that ceramides, especially those consisting of long fatty acids, were internalized into the endocytic pathway in neuroblastoma SH-SY5Y cells to induce exosome secretion through lysosome-associated protein transmembrane 4B (LAPTM4B). Knockdown of LAPTM4B inhibited the ceramide-mediated increase in exosome release completely. Fluorescence microscopy observations indicated that exogenous ceramides promote the transport of multivesicular bodies to the plasma membranes in a LAPTM4B-dependent manner. Similarly, inhibition of acid ceramidase, which tends to induce intracellular ceramide accumulation, increased exosome production by SH-SY5Y cells in a LAPTM4B-dependent manner. Furthermore, the level of amyloid-ß protein (Aß) was decreased in neuronal cells following treatment with exogenous ceramide or inhibition of acid ceramidase, and this effect was attributed to the LAPTM4B-dependent efflux of Aß-containing exosomes. Overall, these findings reveal the novel machinery involved in exosome secretion regulated by ceramides and LAPTM4B, and may contribute to efforts to ameliorate the cellular accumulation of neurodegenerative agents such as Aß. - Glucocerebrosidases catalyze a transgalactosylation reaction that yields a newly-identified brain sterol metabolite, galactosylated cholesterol.
Hisako Akiyama, Mitsuko Ide, Yasuko Nagatsuka, Tomoko Sayano, Etsuro Nakanishi, Norihito Uemura, Kohei Yuyama, Yoshiki Yamaguchi, Hiroyuki Kamiguchi, Ryosuke Takahashi, Johannes M F G Aerts, Peter Greimel, Yoshio Hirabayashi
The Journal of biological chemistry, 295, 16, 5257, 5277, 17 Apr. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, β-Glucocerebrosidase (GBA) hydrolyzes glucosylceramide (GlcCer) to generate ceramide. Previously, we demonstrated that lysosomal GBA1 and nonlysosomal GBA2 possess not only GlcCer hydrolase activity, but also transglucosylation activity to transfer the glucose residue from GlcCer to cholesterol to form β-cholesterylglucoside (β-GlcChol) in vitro β-GlcChol is a member of sterylglycosides present in diverse species. How GBA1 and GBA2 mediate β-GlcChol metabolism in the brain is unknown. Here, we purified and characterized sterylglycosides from rodent and fish brains. Although glucose is thought to be the sole carbohydrate component of sterylglycosides in vertebrates, structural analysis of rat brain sterylglycosides revealed the presence of galactosylated cholesterol (β-GalChol), in addition to β-GlcChol. Analyses of brain tissues from GBA2-deficient mice and GBA1- and/or GBA2-deficient Japanese rice fish (Oryzias latipes) revealed that GBA1 and GBA2 are responsible for β-GlcChol degradation and formation, respectively, and that both GBA1 and GBA2 are responsible for β-GalChol formation. Liquid chromatography-tandem MS revealed that β-GlcChol and β-GalChol are present throughout development from embryo to adult in the mouse brain. We found that β-GalChol expression depends on galactosylceramide (GalCer), and developmental onset of β-GalChol biosynthesis appeared to be during myelination. We also found that β-GlcChol and β-GalChol are secreted from neurons and glial cells in association with exosomes. In vitro enzyme assays confirmed that GBA1 and GBA2 have transgalactosylation activity to transfer the galactose residue from GalCer to cholesterol to form β-GalChol. This is the first report of the existence of β-GalChol in vertebrates and how β-GlcChol and β-GalChol are formed in the brain. - Nrp1 is Activated by Konjac Ceramide Binding-Induced Structural Rigidification of the a1a2 Domain.
Seigo Usuki, Yoshiaki Yasutake, Noriko Tamura, Tomohiro Tamura, Kunikazu Tanji, Takashi Saitoh, Yuta Murai, Daisuke Mikami, Kohei Yuyama, Kenji Monde, Katsuyuki Mukai, Yasuyuki Igarashi
Cells, 9, 2, 24 Feb. 2020, [Peer-reviewed], [International Magazine]
English, Scientific journal, Konjac ceramide (kCer) is a plant-type ceramide composed of various long-chain bases and a-hydroxyl fatty acids. The presence of d4t,8t-sphingadienine is essential for semaphorin 3A (Sema3A)-like activity. Herein, we examined the three neuropilin 1 (Nrp1) domains (a1a2, b1b2, or c), and found that a1a2 binds to d4t,8t-kCer and possesses Sema3A-like activity. kCer binds to Nrp1 with a weak affinity of mM dissociation constant (Kd). We wondered whether bovine serum albumin could influence the ligand-receptor interaction that a1a2 has with a single high affinity binding site for kCer (Kd in nM range). In the present study we demonstrated the influence of bovine serum albumin. Thermal denaturation indicates that the a1a2 domain may include intrinsically disordered region (IDR)-like flexibility. A potential interaction site on the a1 module was explored by molecular docking, which revealed a possible Nrp1 activation mechanism, in which kCer binds to Site A close to the Sema3A-binding region of the a1a2 domain. The a1 module then accesses a2 as the IDR-like flexibility becomes ordered via kCer-induced protein rigidity of a1a2. This induces intramolecular interaction between a1 and a2 through a slight change in protein secondary structure. - Blood-brain barrier permeability analysis of plant ceramides.
Koichi Eguchi, Daisuke Mikami, Hui Sun, Takuya Tsumita, Kaori Takahashi, Katsuyuki Mukai, Kohei Yuyama, Yasuyuki Igarashi
PloS one, 15, 11, e0241640, 2020, [Peer-reviewed], [Corresponding author], [International Magazine]
English, Scientific journal, Ceramides, a type of sphingolipid, are cell membrane components and lipid mediators that modulate a variety of cell functions. In plants, ceramides are mostly present in a glucosylated glucosylceramide (GlcCer) form. We previously showed that oral administration of konjac-derived GlcCer to a mouse model of Alzheimer's disease reduced brain amyloid-β and amyloid plaques. Dietary plant GlcCer compounds are absorbed as ceramides, but it is unclear whether they can cross the blood-brain barrier (BBB). Herein, we evaluated the BBB permeability of synthetic plant-type ceramides (4, 8-sphingadienine, d18:2) using mouse and BBB cell culture models, and found that they could permeate the BBB both in vivo and in vitro. In addition, administrated ceramides were partially metabolized to other sphingolipid species, namely sphingomyelin (SM) and GlcCer, while crossing the BBB. Thus, plant ceramides can cross the BBB, suggesting that ceramides and their metabolites might affect brain functions. - Plant sphingolipids promote extracellular vesicle release and alleviate amyloid-β pathologies in a mouse model of Alzheimer's disease.
Kohei Yuyama, Kaori Takahashi, Seigo Usuki, Daisuke Mikami, Hui Sun, Hisatoshi Hanamatsu, Junichi Furukawa, Katsuyuki Mukai, Yasuyuki Igarashi
Scientific reports, 9, 1, 16827, 16827, 14 Nov. 2019, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
English, Scientific journal, The accumulation of amyloid-β protein (Aβ) in brain is linked to the early pathogenesis of Alzheimer's disease (AD). We previously reported that neuron-derived exosomes promote Aβ clearance in the brains of amyloid precursor protein transgenic mice and that exosome production is modulated by ceramide metabolism. Here, we demonstrate that plant ceramides derived from Amorphophallus konjac, as well as animal-derived ceramides, enhanced production of extracellular vesicles (EVs) in neuronal cultures. Oral administration of plant glucosylceramide (GlcCer) to APP overexpressing mice markedly reduced Aβ levels and plaque burdens and improved cognition in a Y-maze learning task. Moreover, there were substantial increases in the neuronal marker NCAM-1, L1CAM, and Aβ in EVs isolated from serum and brain tissues of the GlcCer-treated AD model mice. Our data showing that plant ceramides prevent Aβ accumulation by promoting EVs-dependent Aβ clearance in vitro and in vivo provide evidence for a protective role of plant ceramides in AD. Plant ceramides might thus be used as functional food materials to ameliorate AD pathology. - Malabaricone C as Natural Sphingomyelin Synthase Inhibitor against Diet-Induced Obesity and Its Lipid Metabolism in Mice.
Muhamad Aqmal Othman, Kohei Yuyama, Yuta Murai, Yasuyuki Igarashi, Daisuke Mikami, Yasodha Sivasothy, Khalijah Awang, Kenji Monde
ACS medicinal chemistry letters, 10, 8, 1154, 1158, 08 Aug. 2019, [Peer-reviewed], [International Magazine]
English, Scientific journal, The interaction between natural occurring inhibitors and targeted membrane proteins could be an alternative medicinal strategy for the treatment of metabolic syndrome, notably, obesity. In this study, we identified malabaricones A-C and E (1-4) isolated from the fruits of Myristica cinnamomea King as natural inhibitors for sphingomyelin synthase (SMS), a membrane protein responsible for sphingolipid biosynthesis. Having the most promising inhibition, oral administration of compound 3 exhibited multiple efficacies in reducing weight gain, improving glucose tolerance, and reducing hepatic steatosis in high fat diet-induced obesity mice models. Liver lipid analysis revealed a crucial link between the SMS activities of compound 3 and its lipid metabolism in vitro and in vivo. The nontoxic nature of compound 3 makes it a suitable candidate in search of drugs which can be employed in the treatment and prevention of obesity. - Isolation of Sphingoid Bases from Starfish Asterias amurensis Glucosylceramides and Their Effects on Sphingolipid Production in Cultured Keratinocytes
Daisuke Mikami, Shota Sakai, Kohei Yuyama, Yasuyuki Igarashi
Journal of Oleo Science, 68, 5, 427, 441, 2019, [Peer-reviewed]
English, Scientific journal - Extracellular vesicles from amnion-derived mesenchymal stem cells ameliorate hepatic inflammation and fibrosis in rats
Masatsugu Ohara, Shunsuke Ohnishi, Hidetaka Hosono, Koji Yamamoto, Kohei Yuyama, Hideki Nakamura, Qingjie Fu, Osamu Maehara, Goki Suda, Naoya Sakamoto
Stem Cells International, 2018, 3212643, 3212643, Dec. 2018, [Peer-reviewed], [International Magazine]
English, Scientific journal, Background: There are no approved drug treatments for liver fibrosis and nonalcoholic steatohepatitis (NASH), an advanced stage of fibrosis which has rapidly become a major cause of cirrhosis. Therefore, development of anti-inflammatory and antifibrotic therapies is desired. Mesenchymal stem cell- (MSC-) based therapy, which has been extensively investigated in regenerative medicine for various organs, can reportedly achieve therapeutic effect in NASH via paracrine action. Extracellular vesicles (EVs) encompass a variety of vesicles released by cells that fulfill functions similar to those of MSCs. We herein investigated the therapeutic effects of EVs from amnion-derived MSCs (AMSCs) in rats with NASH and liver fibrosis. Methods: NASH was induced by a 4-week high-fat diet (HFD), and liver fibrosis was induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl4) twice a week for six weeks. AMSC-EVs were intravenously injected at weeks 3 and 4 in rats with NASH (15 μg/kg) and at week 3 in rats with liver fibrosis (20 μg/kg). The extent of inflammation and fibrosis was evaluated with quantitative reverse transcription polymerase chain reaction and immunohistochemistry. The effect of AMSC-EVs on inflammatory and fibrogenic response was investigated in vitro. Results: AMSC-EVs significantly decreased the number of Kupffer cells (KCs) in the liver of rats with NASH and the mRNA expression levels of inflammatory cytokines such as tumor necrosis factor- (Tnf-) α, interleukin- (Il-) 1β and Il-6, and transforming growth factor- (Tgf-) β. Furthermore, AMSC-EVs significantly decreased fiber accumulation, KC number, and hepatic stellate cell (HSC) activation in rats with liver fibrosis. In vitro, AMSC-EVs significantly inhibited KC and HSC activation and suppressed the lipopolysaccharide (LPS)/toll-like receptor 4 (TLR4) signaling pathway. Conclusions: AMSC-EVs ameliorated inflammation and fibrogenesis in a rat model of NASH and liver fibrosis, potentially by attenuating HSC and KC activation. AMSC-EV administration should be considered as a new therapeutic strategy for chronic liver disease. - Multiple roles of Sms2 in white and brown adipose tissues from diet-induced obese mice
Hisatoshi Hanamatsu, Susumu Mitsutake, Shota Sakai, Toshiro Okazaki, Ken Watanabe, Yasuyuki Igarashi, Kohei Yuyama
J Metabolic Syndrome, 2018, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Konjac ceramide (kCer) regulates NGF-induced neurite outgrowth via the sema3A signaling pathway
Seigo Usuki, Noriko Tamura, Kohei Yuyama, Tomohiro Tamura, Katsuyuki Mukai, Yasuyuki Igarashi
Journal of Oleo Science, 67, 1, 77, 86, Japan Oil Chemists Society, 2018, [Peer-reviewed]
English, Scientific journal - Direct Involvement of Arachidonic Acid in the Development of Ear Edema via TRPV3
Takao Sanaki, Erika Kasai-Yamamoto, Takeshi Yoshioka, Shota Sakai, Kohei Yuyama, Takuji Fujiwara, Yoshito Numata, Yasuyuki Igarashi
JOURNAL OF OLEO SCIENCE, 66, 6, 591, 599, Jun. 2017, [Peer-reviewed]
English, Scientific journal - Synthesis of Nontoxic Fluorous Sphingolipids as Molecular Probes of Exogenous Metabolic Studies for Rapid Enrichment by Fluorous Solid Phase Extraction
Shota Saito, Yuta Murai, Seigo Usuki, Masafumi Yoshida, Mostafa A. S. Hammam, Susumu Mitsutake, Kohei Yuyama, Yasuyuki Igarashi, Kenji Monde
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2017, 6, 1045, 1051, Feb. 2017, [Peer-reviewed]
English, Scientific journal - A potential function for neuronal exosomes: Sequestering intracerebral amyloid-beta peptide
Kohei Yuyama, Hui Sun, Seigo Usuki, Shota Sakai, Hisatoshi Hanamatsu, Tetsuo Mioka, Nobuyuki Kimura, Megumi Okada, Hidetoshi Tahara, Jun-ichi Furukawa, Naoki Fujitani, Yasuro Shinohara, Yasuyuki Igarashi
FEBS LETTERS, 589, 1, 84, 88, Jan. 2015, [Peer-reviewed], [Lead author]
English, Scientific journal - Altered levels of serum sphingomyelin and ceramide containing distinct acyl chains in young obese adults
H. Hanamatsu, S. Ohnishi, S. Sakai, K. Yuyama, S. Mitsutake, H. Takeda, S. Hashino, Y. Igarashi
NUTRITION & DIABETES, 4, e141, Oct. 2014, [Peer-reviewed]
English, Scientific journal - Decreased Amyloid-beta Pathologies by Intracerebral Loading of Glycosphingolipid-enriched Exosomes in Alzheimer Model Mice
Kohei Yuyama, Hui Sun, Shota Sakai, Susumu Mitsutake, Megumi Okada, Hidetoshi Tahara, Jun-ichi Furukawa, Naoki Fujitani, Yasuro Shinohara, Yasuyuki Igarashi
JOURNAL OF BIOLOGICAL CHEMISTRY, 289, 35, 24488, 24498, Aug. 2014, [Peer-reviewed], [Lead author]
English, Scientific journal - Involvement of gangliosides in the process of Cbp/PAG phosphorylation by Lyn in developing cerebellar growth cones
Naoko Sekino-Suzuki, Kohei Yuyama, Toshiaki Miki, Mizuho Kaneda, Hidenori Suzuki, Naomasa Yamamoto, Tadashi Yamamoto, Chitose Oneyama, Masato Okada, Kohji Kasahara
JOURNAL OF NEUROCHEMISTRY, 124, 4, 514, 522, Feb. 2013, [Peer-reviewed]
English, Scientific journal - Cooperative Synthesis of Ultra Long-Chain Fatty Acid and Ceramide during Keratinocyte Differentiation.
Yukiko Mizutani, Hui Sun, Yusuke Ohno, Takayuki Sassa, Takeshi Wakashima, Mari Obara, Kohei Yuyama, Akio Kihara, Yasuyuki Igarashi
PloS one, 8, 6, e67317, 2013, [Peer-reviewed], [International Magazine]
English, Scientific journal, The lipid lamellae in the stratum corneum is important for the epidermal permeability barrier. The lipid lamellae component ceramide (CER), comprising an ultra long-chain (ULC) fatty acid (FA) of ≥26 carbons (ULC CER), plays an essential role in barrier formation. ULC acyl-CoAs, produced by the FA elongase ELOVL4, are converted to ULC CERs by the CER synthase CERS3. In the presented study, we observed that ELOVL4 and CERS3 mRNAs increased during keratinocyte differentiation in vivo and in vitro. We also determined that peroxisome proliferator-activated receptor β/δ is involved in the up-regulation of the mRNAs. Knockdown of CERS3 caused a reduction in the elongase activities toward ULC acyl-CoAs, suggesting that CERS3 positively regulates ULCFA. Thus, we reveal that the two key players in ULC CER production in epidermis, CERS3 and ELOVL4, are coordinately regulated at both the transcriptional and enzymatic levels. - Sphingolipid-modulated Exosome Secretion Promotes Clearance of Amyloid-beta by Microglia
Kohei Yuyama, Hui Sun, Susumu Mitsutake, Yasuyuki Igarashi
JOURNAL OF BIOLOGICAL CHEMISTRY, 287, 14, 10977, 10989, Mar. 2012, [Peer-reviewed], [Lead author]
English, Scientific journal - Ganglioside GD3 monoclonal antibody-induced paxillin tyrosine phosphorylation and filamentous actin assembly in cerebellar growth cones
Kohei Yuyama, Naoko Sekino-Suzuki, Naomasa Yamamoto, Kohji Kasahara
JOURNAL OF NEUROCHEMISTRY, 116, 5, 845, 850, Mar. 2011, [Peer-reviewed], [Lead author]
English, Scientific journal - Sphingomyelin accumulation provides a favorable milieu for GM1 ganglioside-induced assembly of amyloid beta-protein
Kohei Yuyama, Katsuhiko Yanagisawa
NEUROSCIENCE LETTERS, 481, 3, 168, 172, Sep. 2010, [Peer-reviewed], [Lead author]
English, Scientific journal - Gangliosides determine the amyloid pathology of Alzheimer's disease
Naoto Oikawa, Haruyasu Yamaguchi, Koichi Ogino, Takao Taki, Kohei Yuyama, Naoki Yamamoto, Ryong-Woon Shin, Koichi Furukawa, Katsuhiko Yanagisawa
NEUROREPORT, 20, 12, 1043, 1046, Aug. 2009, [Peer-reviewed]
English, Scientific journal - Late endocytic dysfunction as a putative cause of amyloid fibril formation in Alzheimer's disease
Kohei Yuyama, Katsuhiko Yanagisawa
JOURNAL OF NEUROCHEMISTRY, 109, 5, 1250, 1260, Jun. 2009, [Peer-reviewed], [Lead author]
English, Scientific journal - Accelerated release of exosome-associated GM1 ganglioside (GM1) by endocytic pathway abnormality: another putative pathway for GM1-induced amyloid fibril formation
Kohei Yuyama, Naoki Yamamoto, Katsuhiko Yanagisawa
JOURNAL OF NEUROCHEMISTRY, 105, 1, 217, 224, Apr. 2008, [Peer-reviewed], [Lead author]
English, Scientific journal - Translocation of activated heterotrimeric G protein G alpha(o) to ganglioside-enriched detergent-resistant membrane rafts in developing cerebellum
Kohei Yuyama, Naoko Sekino-Suzuki, Yutaka Sanai, Kohji Kasahara
JOURNAL OF BIOLOGICAL CHEMISTRY, 282, 36, 26392, 26400, Sep. 2007, [Peer-reviewed], [Lead author]
English, Scientific journal - Permeability of water through a raft model membrane clarified by time-resolved SANS and SAXS
Mitsuhiro Hirai, Teruaki Onai, Masaharu Koizumi, Harutaka Hirai, Kohji Kasahara, Naoko Suzuki, Kohei Yuyama, Katsuaki Inoue
JOURNAL OF APPLIED CRYSTALLOGRAPHY, 40, S159, S164, Apr. 2007, [Peer-reviewed]
English, Scientific journal - Chloroquine-induced endocytic pathway abnormalities: Cellular model of GM1 ganglioside-induced A beta fibrillogenesis in Alzheimer's disease
Kohei Yuyama, Naoki Yamamoto, Katsuhiko Yanagisawa
FEBS LETTERS, 580, 30, 6972, 6976, Dec. 2006, [Peer-reviewed], [Lead author]
English, Scientific journal - Structure of raft-model membrane by using the inverse contrast variation neutron scattering method
Mitsuhiro Hirai, Harutaka Hirai, Masaharu Koizumi, Kohji Kasahara, Kohei Yuyama, Naoko Suzuki
PHYSICA B-CONDENSED MATTER, 385-86, 868, 870, Nov. 2006, [Peer-reviewed]
English, Scientific journal - Low concentrations of nitric oxide (NO) induced cell death in PC12 cells through activation of p38 mitogen-activated protein kinase (p38 MAPK) but not via extracellular signal-regulated kinases (ERK1/2) or c-Jun N-terminal protein kinase (JNK)
T Yamamoto, K Yuyama, H Yamamoto
NEUROSCIENCE LETTERS, 392, 3, 170, 173, Jan. 2006, [Peer-reviewed]
English, Scientific journal - Structures and dynamics of glycosphingolipid-containing lipid mixtures as raft models of plasma membrane
M Hirai, M Koizumi, H Hirai, T Hayakawa, K Yuyama, N Suzuki, K Kasahara
JOURNAL OF PHYSICS-CONDENSED MATTER, 17, 31, S2965, S2977, Aug. 2005, [Peer-reviewed]
English, Scientific journal - [Lipid microdomains in nervous system].
Sekino-Suzuki N, Yuyama K, Sanai Y, Kasahara K
Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme, 49, 2397, 2403, 15 Suppl, Nov. 2004, [Peer-reviewed] - Caspase-independent cell death by low concentrations of nitric oxide in PC12 cells: Involvement of cytochrome c oxidase inhibition and the production of reactive oxygen species in mitochondria
K Yuyama, H Yamamoto, Nishizaki, I, T Kato, Sora, I, T Yamamoto
JOURNAL OF NEUROSCIENCE RESEARCH, 73, 3, 351, 363, Aug. 2003, [Peer-reviewed], [Lead author]
English, Scientific journal - Overexpression of V-1 prevents nitric oxide-induced cell death: Involvement of enhanced tetrahydrobiopterin biosynthesis
K Yuyama, H Yamamoto, K Nakamura, Nishizaki, I, T Yamakuni, SY Song, Sora, I, T Nagatsu, T Yamamoto
JOURNAL OF NEUROSCIENCE RESEARCH, 72, 6, 716, 725, Jun. 2003, [Peer-reviewed]
English, Scientific journal - Resistance of PC12 cells against nitric oxide (NO)-induced toxicity in long-term culture: implication of neuronal NO synthase expression
K Yuyama, H Yamamoto, K Nakamura, T Kato, Sora, I, T Yamamoto
NEUROSCIENCE LETTERS, 309, 3, 169, 172, Aug. 2001, [Peer-reviewed], [Lead author]
English, Scientific journal - Kinetic characterization of the nitric oxide toxicity for PC12 cells: effect of half-life time of NO release
T Yamamoto, K Yuyama, K Nakamura, T Kato, H Yamamoto
EUROPEAN JOURNAL OF PHARMACOLOGY, 397, 1, 25, 33, May 2000, [Peer-reviewed]
English, Scientific journal - Kinetic analysis of nitric oxide (NO) release from several NO-donors using fluorescence dye, diaminofluorescein-2 (DAF-2).
C Tamura, N Tanaka, K Yuyama, T Kato, H Yamamoto, T Yamamoto
FRONTIERS OF THE MECHANISMS OF MEMORY AND DEMENTIA, 1200, 91, 92, 2000, [Peer-reviewed]
English, International conference proceedings
Other Activities and Achievements
- アルツハイマー病における血液細胞外小胞バイオマーカーの開発
湯山耕平, 老年期認知症研究会誌, 25, 3, 28, 30, 26 Sep. 2024, [Invited], [Lead author, Last author, Corresponding author]
Japanese - Study of extracellular vesicle biomarkers for detection of brain amyloid accumulation
Kohei Yuyama, Hui Sun, Kenji Monde, Takumi Hirase, Yoichi Makino, Precision Medicine, 7, 8, 663, 667, Jul. 2024
Japanese, Report scientific journal - 細胞外小胞のデジタル検出法開発―アルツハイマー病早期検出への応用―
湯山 耕平, 孫 慧, 門出 健次, 平瀬 匠, 牧野 洋一, Medical Science Digest, 49, 432, 435, Aug. 2023
Introduction scientific journal - Linking glycosphingolipids to Alzheimer's amyloid-ß: extracellular vesicles and functional plant materials.
Kohei Yuyama, Yasuyuki Igarashi, Glycoconjugate journal, 39, 5, 613, 618, Oct. 2022, [International Magazine]
Glycosphingolipids (GSLs) are a specialized class of membrane lipids composed of a ceramide and a carbohydrate head group. GSLs are localized in cell membranes and were recently found to be enriched in the membrane of neuron-derived exosomes, which are a type of extracellular vesicle. Our studies demonstrated that exosomal GSLs may be associated with the amyloid-ß (Aß) peptide, a principal agent of Alzheimer's disease (AD), and act to clear Aß by transporting Aß into brain phagocytic microglia. In this review, we summarize and discuss the function of exosomal GSLs in Aß homeostasis in AD pathology. Improvement in Aß clearance is a potent strategy for AD prevention and therapy. Dietary glucosylceramides (GlcCer) isolated from plants are absorbed into the body as various metabolites, including ceramides. Our recent work demonstrated that dietary GlcCer accelerates neuronal exosome production, which facilitates Aß clearance in mice. Furthermore, studies of AD model mice and human clinical trials have found that oral administration of plant-type GlcCer attenuates the Aß burden in the brain. We also introduce the development of plant-type GlcCer as functional food materials to prevent AD., English - Roles of sphingolipids in neurodegenerative diseases
Kohei Yuyama, Yasuyuki Igarashi, Journal of Japanese Biochemical Society, 92, 5, 640, 648, Oct. 2020, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
Japanese, Introduction scientific journal - 広がりを見せる食餌性植物セラミドの生体調節機能
湯山耕平, 江口晃一, 五十嵐靖之, バイオサイエンスとインダストリー, 78, 4, 302, 307, Jul. 2020, [Invited], [Lead author]
Japanese, Introduction scientific journal - こんにゃくセラミドによるエクソソーム産生誘導と認知症予防効果
江口晃一, 向井克之, 湯山耕平, 五十嵐靖之, FOODSTYLE21, 38, 41, Feb. 2020, [Invited]
Japanese, Introduction scientific journal - Exosomes as Carriers of Alzheimer's Amyloid-beta
Kohei Yuyama, Yasuyuki Igarashi, FRONTIERS IN NEUROSCIENCE, 11, Apr. 2017
English, Book review - Physiological and pathological roles of exosomes in the nervous system
Kohei Yuyama, Yasuyuki Igarashi, Biomolecular Concepts, 7, 1, 53, 68, 01 Feb. 2016
Walter de Gruyter GmbH, English, Book review - Exosome-dependent clearance of amyloid-β protein
湯山耕平, 五十嵐靖之, 細胞, 48, 1, 44, 47, Jan. 2016, [Invited], [Lead author, Corresponding author]
ニューサイエンス社, Japanese, Introduction scientific journal - The function of neuronal exosomes in sequestering Alzheimer's amyloid-β
湯山耕平, 五十嵐靖之, Dementia Japan, 30, 3, 358, 366, 2016, [Invited], [Lead author, Corresponding author]
日本認知症学会, Japanese, Introduction scientific journal - Pathological roles of ceramide and its metabolites in metabolic syndrome and Alzheimer's disease
Kohei Yuyama, Susumu Mitsutake, Yasuyuki Igarashi, BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS, 1841, 5, 793, 798, May 2014, [Lead author]
English - Heterotrimeric G proteins and lipid rafts
湯山耕平, 鈴木直子, 笠原浩二, 生体の科学, 60, 3, 181, 186, 2009, [Invited], [Lead author]
金原一郎記念医学医療振興財団, Japanese, Introduction scientific journal - アルツハイマー病におけるエンドサイトーシス障害
湯山耕平, 柳澤勝彦, Dementia Japan, 23, 1, 47, 54, 2009, [Invited], [Lead author]
Japanese, Introduction scientific journal - [Lipid rafts and heterotrimeric G proteins].
Yuyama K, Sekino-Suzuki N, Kasahara K, Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme, 53, 1558, 1563, 2008, [Invited], [Lead author]
12 Suppl, Japanese - Signal transduction of heterotrimeric G proteins in lipid rafts
Kohei Yuyama, Naoko Sekino-Suzuki, Kohji Kasahara, TRENDS IN GLYCOSCIENCE AND GLYCOTECHNOLOGY, 19, 105, 19, 27, Jan. 2007, [Invited], [Lead author]
English, Book review - 神経細胞接着分子TAG-1の脂質ラフトを介するシグナル伝達
湯山耕平, 鈴木直子, 佐内豊, 笠原浩二, MEMBRANE, 30, 91, 93, 2005, [Lead author]
Japanese, Introduction scientific journal - 神経系における脂質マイクロドメイン
鈴木直子, 湯山耕平, 佐内豊, 笠原浩二, 蛋白質 核酸 酵素, 49, 2397, 2403, 2004, [Invited]
Japanese, Introduction scientific journal - Lipid rafts in cellular signaling and disease
K Yuyama, N Sekino-Suzuki, Y Sanai, K Kasahara, TRENDS IN GLYCOSCIENCE AND GLYCOTECHNOLOGY, 15, 83, 139, 151, May 2003, [Invited], [Lead author]
English, Book review
Books and other publications
- セラミド研究の新展開 : 基礎から応用へ
湯山耕平, 五十嵐靖之, 第20章 細胞外小胞の生産・機能に関わるセラミド関連脂質のはたらき
食品化学新聞社, 01 Jun. 2019, 9784916143358, 337p, Japanese, [Contributor] - 認知症の早期診断技術と進行抑制/予防薬・機能性食品の開発
湯山耕平、五十嵐靖之, 6章5節 認知症病理形成にかかわるエクソソームの働きとその予防・治療標的可能性
技術情報協会, 26 Apr. 2019, 9784861047442, 486p, Japanese, [Contributor] - 認知症の早期診断技術と進行抑制/予防薬・機能性食品の開発
高橋香織, 湯山耕平, 向井克之, 五十嵐靖之, 9章12節 セラミドを利用したアルツハイマー病予防法の研究開発
技術情報協会, Apr. 2019, 9784861047442, 486p, Japanese, [Contributor] - 医療を変えるエクソソーム : 生体機能から疾患メカニズム、臨床応用まで
湯山耕平, 五十嵐靖之, 第４章 神経変性疾患の病態発現にかかわるエクソソームの働き
化学同人, 25 Aug. 2018, 9784759819786, viii, 231p, Japanese, [Contributor] - パラダイムシフトをもたらすエクソソーム機能研究最前線～シグナル伝達からがん、免疫、神経疾患との関わり、創薬利用まで～
湯山耕平, 五十嵐靖之, 第5章 第2節 アルツハイマー病とエクソソーム
NTS出版, 08 Mar. 2017, [Contributor]
Lectures, oral presentations, etc.
- Ceramide-dependent exosome production and their functions in neurodegenerative diseases
Kohei Yuyama
第12回セラミド研究会学術集会, 25 Oct. 2019, Japanese, Invited oral presentation
[Invited], [Domestic Conference] - Sphingoid long chain bases: Their structural diversity, absorption, and functions for skin improvement
Daisuke Mikami, Shota Sakai, Megumi Nishimukai, Kohei Yuyama, Yasuyuki Igarashi
7th International Singapore Lipid Symposium (ISLS7), 09 Mar. 2018, English, Oral presentation
[International presentation]
Research Themes
- デジタル測定による脳内アミロイドβ蓄積とアミロイドβ結合エクソソーム量の相関解析
科学研究費助成事業
01 Apr. 2022 - 31 Mar. 2025
湯山 耕平
日本学術振興会, 基盤研究(C), 北海道大学, 22K07341 - The mechnisms of physiological exosome delivery to neurons
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
Apr. 2018 - Mar. 2021
Yuyama Kohei
In brains, the exosomes, a type of extracellular vesicles, released from microglia contain tau protein, a pathogenic agent of Alzheimer's disease, and transport them into neurons, contributing pathogenesis of the disease. However, the molecular mechanism for exosome targeting to neurons remains unclear. In this study, I found that a specific sialic acid-containing sugar chain of glycoprotein was involved in the transport of microglia-derived exosomes to neurons.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 18K06456 - 画期的医薬品等の創出をめざす脂質の生理活性と機能の解明
革新的先端研究開発支援事業（AMED-CREST）
Apr. 2017 - Mar. 2021
湯山耕平
国立研究開発法人日本医療研究開発機構 (AMED), 脂質による体表面バリア形成の分子機構の解明, Coinvestigator - Exosome-like synthetic liposomes containing glycosphingolipids for therapy of Alzheimer's disease
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
Apr. 2014 - Mar. 2017
Yuyama Kohei
Exosome is a subtype of extracellular vesicle, released from various cells including brain neurons. Neuronal cell line (N2a)-derived exosomes can bind amyloid-beta peptide (Abeta) in GSL-dependent manner and clear it through transporting into microglia. In this study, we validated that mouse neuronal exosomes, not glial ones, had abundant GSLs and could capture Abeta. Infusion of the neuronal exosomes into APP transgenic mice decreased Abeta and amyloid depositions, similar to previously reported neuroblastoma-derived exosomes. However, synthetic liposomes containing neuronal GSLs had no potency to bind Abeta. Future challenge is to construct exosome-like liposomes referred to total lipidomics data of neuronal exosomes.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 26440041 - Clearance of neuronal exosomes in brain平成25年5月20日現在
Grants-in-Aid for Scientific Research
2011 - 2011
YUYAMA Kohei
Exosome is a subtype of extracellular vesicle, released from various cells including brain neurons. A well known function of exosome is to remove obsolete or misfolded proteins from cells, however, the mechanism how exosomes are processed in extracellular space of brain remained unclear. In this study, we searched type of cells, which can uptake neuronal exosomes, and found that microglia can uptake the exosomes and degrade the exosome-associated proteins.
Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, Principal investigator, Competitive research funding, 23700435 - Effect of exosome-associated gangliosides on the assembly of amyloid-β protein
Grants-in-Aid for Scientific Research(若手研究(B))
2009 - 2010
Kohei YUYAMA
Alzheimer's disease is pathologically featured by extraneuronal deposition of amyloid fibrils, which are composed of amyloid-β protein (Aβ). However, it still remains to be clarified how soluble monomeric Aβ assemble into fibrils. In the present study, we found that ganglioside GM1 is release from mouse primary cortical neurons, in the association with exosome. Furthermore, the exosome-associated GM1 accelerated the assembly of synthetic Aβ in vitro.
Ministry of Education, Culture, Sports, Science and Technology, 若手研究(B), 国立長寿医療センター(研究所)->独立行政法人国立長寿医療研究センター->北海道大学, Principal investigator, Competitive research funding, 21770128
