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| 1.
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浅野, 雄哉 ; 石丸, 和宏 ; 多久和, 陽 ; Asano, Yuya ; Ishimaru, Kazuhiro ; Takuwa, Yoh
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修士課程優秀論文
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| 2.
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Zhao, Juanjuan ; Okamoto, Yasuo ; Asano, Yuya ; Ishimaru, Kazuhiro ; Aki, Sho ; Yoshioka, Kazuaki ; Takuwa, Noriko ; Wada, Takashi ; Inagaki, Yutaka ; Takahashi, Chiaki ; Nishiuchi, Takumi ; Takuwa, Yoh ; 安藝, 翔 ; 吉岡, 和晃 ; 多久和, 典子 ; 和田, 隆志 ; 髙橋, 智聡 ; 西内, 巧 ; 多久和, 陽
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金沢大学医薬保健研究域医学系<br />Idiopathic pulmonary fibrosis is a devastating disease with poor prognosis. The pathogenic role of t
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he lysophospholipid mediator sphingosine-1-phosphate and its receptor S1PR2 in lung fibrosis is unknown. We show here that genetic deletion of S1pr2 strikingly attenuated lung fibrosis induced by repeated injections of bleomycin in mice. We observed by using S1pr2 LacZ/+ mice that S1PR2 was expressed in alveolar macrophages, vascular endothelial cells and alveolar epithelial cells in the lung and that S1PR2-expressing cells accumulated in the fibrotic legions. Bone marrow chimera experiments suggested that S1PR2 in bone marrow–derived cells contributes to the development of lung fibrosis. Depletion of macrophages greatly attenuated lung fibrosis. Bleomycin administration stimulated the mRNA expression of the profibrotic cytokines IL-13 and IL-4 and the M2 markers including arginase 1, Fizz1/Retnla, Ccl17 and Ccl24 in cells collected from broncho-alveolar lavage fluids (BALF), and S1pr2 deletion markedly diminished the stimulated expression of these genes. BALF cells from bleomycin–administered wild-type mice showed a marked increase in phosphorylation of STAT6, a transcription factor which is activated downstream of IL-13, compared with saline–administered wild-type mice. Interestingly, in bleomycin–adminis-tered S1pr2 -/- mice, STAT6 phosphorylation in BALF cells was substantially diminished compared with wild-type mice. Finally, pharmacological S1PR2 blockade in S1pr2 +/+ mice alleviated bleomycin–induced lung fibrosis. Thus, S1PR2 facilitates lung fibrosis through the mechanisms involving augmentation of IL-13 expression and its signaling in BALF cells, and represents a novel target for treating lung fibrosis. © 2018 Zhao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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Pham, Hoa Q. ; Yoshioka, Kazuaki ; Mohri, Hiromi ; Nakata, Hiroki ; Aki, Sho ; Ishimaru, Kazuhiro ; Takuwa, Noriko ; Takuwa, Yoh ; 吉岡, 和晃 ; 仲田, 浩規 ; 安藝, 翔 ; 多久和, 典子 ; 多久和, 陽
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金沢大学医薬保健研究域医学系<br />Phosphatidylinositol 3-phosphate (PI(3)P) is the predominant phosphoinositide species in early endos
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omes and autophagosomes, in which PI(3)P dictates traffic of these organelles. Phosphoinositide levels are tightly regulated by lipid-kinases and -phosphatases; however, a phosphatase that converts PI(3)P back to phosphatidylinositol in the endosomal and autophagosomal compartments is not fully understood. We investigated the subcellular distribution and functions of myotubularin-related protein-4 (MTMR4), which is distinct among other MTMRs in that it possesses a PI(3)P-binding FYVE domain, in lung alveolar epithelium-derived A549 cells. MTMR4 was localized mainly in late endosomes and autophagosomes. MTMR4 knockdown markedly suppressed the motility, fusion, and fission of PI(3)P-enriched structures, resulting in decreases in late endosomes, autophagosomes, and lysosomes, and enlargement of PI(3)P-enriched early and late endosomes. In amino acid- and serum-starved cells, MTMR4 knockdown decreased both autophagosomes and autolysosomes and markedly increased PI(3)P-containing autophagosomes and late endosomes, suggesting that the fusion with lysosomes of autophagosomes and late endosomes might be impaired. Notably, MTMR4 knockdown inhibited the nuclear translocation of starvation stress responsive transcription factor-EB (TFEB) with reduced expression of lysosome-related genes in starved cells. These findings indicate that MTMR4 is essential for the integrity of endocytic and autophagic pathways. © 2018 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.<br />Embargo Period 12 months
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Aung, Khin Thuzar ; Yoshioka, Kazuaki ; Aki, Sho ; Ishimaru, Kazuhiro ; Takuwa, Noriko ; Takuwa, Yoh ; 吉岡, 和晃 ; 安藝, 翔 ; 多久和, 典子 ; 多久和, 陽
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金沢大学医薬保健研究域医学系<br />Pinocytosis is an important fundamental cellular process that is used by the cell to transport fluid
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and solutes. Phosphoinositide 3-kinases (PI3Ks) regulate a diverse array of dynamic membrane events. However, it is not well-understood which PI3K isoforms are involved in specific mechanisms of pinocytosis. We performed knockdown studies of endogenous PI3K isoforms and clathrin heavy chain (CHC) mediated by small interfering RNA (siRNA). The results demonstrated that the class II PI3K PI3K-C2α and PI3K-C2β, but not the class I or III PI3K, were required for pinocytosis, based on an evaluation of fluorescein-5-isothiocyanate (FITC)–dextran uptake in endothelial cells. Pinocytosis was partially dependent on both clathrin and dynamin, and both PI3K-C2α and PI3K-C2β were required for clathrin-mediated—but not clathrin-non-mediated—FITC-dextran uptake at the step leading up to its delivery to early endosomes. Both PI3K-C2α and PI3K-C2β were co-localized with clathrin-coated pits and vesicles. However, PI3K-C2β, but not PI3K-C2α, was highly co-localized with actin filament-associated clathrin-coated structures and required for actin filament formation at the clathrin-coated structures. These results indicate that PI3K-C2α and PI3K-C2β play differential, indispensable roles in clathrin-mediated pinocytosis. © 2018, The Physiological Society of Japan and Springer Japan KK, part of Springer Nature.<br />Embargo Period 12 months
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Sarker, Md Azadul Kabir ; Aki, Sho ; Yoshioka, Kazuaki ; Kuno, Kouji ; Okamoto, Yasuo ; Ishimaru, Kazuhiro ; Takuwa, Noriko ; Takuwa, Yoh ; 安藝, 翔 ; 吉岡, 和晃 ; 多久和, 典子 ; 多久和, 陽
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金沢大学医薬保健研究域医学系<br />Class II phosphoinositide 3-kinases (PI3Ks), PI3K-C2α and PI3K-C2β, are highly homologous and distin
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ct from class I and class III PI3Ks in catalytic products and domain structures. In contrast to class I and class III PI3Ks, physiological roles of PI3K-C2α and PI3K-C2β are not fully understood. Because we previously demonstrated that PI3K-C2α is involved in vascular smooth muscle contraction, we studied the phenotypes of smooth muscle-specific knockout (KO) mice of PI3K-C2α and PI3K-C2β. The pup numbers born from single PI3K-C2α-KO and single PI3K-C2β-KO mothers were similar to those of control mothers, but those from double KO (DKO) mothers were smaller compared with control mice. However, the number of intrauterine fetuses in pregnant DKO mothers was similar to that in control mice. Both spontaneous and oxytocin-induced contraction of isolated uterine smooth muscle (USM) strips was diminished in DKO mice but not in either of the single KO mice, compared with control mice. Furthermore, contraction of USM of DKO mice was less sensitive to a Rho kinase inhibitor. Mechanistically, the extent of oxytocin-induced myosin light chain phosphorylation was greatly reduced in USM from DKO mice compared with control mice. The oxytocin-induced rise in the intracellular Ca2+ concentration in USM was similar in DKO and control mice. However, Rho activation in the intracellular compartment was substantially attenuated in DKO mice compared with control mice, as evaluated by fluorescence resonance energy transfer imaging technique. These data indicate that both PI3K-C2α and PI3K-C2β are required for normal USM contraction and parturition mainly through their involvement in Rho activation.<br />Embargo Period 12 months
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Juanjuan, Zhao ; Okamoto, Yasuo ; Takuwa, Yoh
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The lysophospholipid mediator sphingosine-1-phosphate (S1P) exerts diverse biological activities including the regulatio
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n of leukocyte migration and vascular barrier integrity, suggesting that S1P signaling could be involved in inflammatory fibrotic diseases. Pulmonary fibrosis is a devastating disease characterized by fibroblast accumulation and extracellular matrix deposition in lungs, and bleomycin–induced pulmonary fibrosis is the most widely used experimental model. We studied the effects of the S1P–specific receptor S1P2 on the phenotypes of lung fibroblasts isolated from bleomycin- and saline-administered wild-type and S1P2–null (S1pr2-/-) mice. The lung fibroblasts from bleomycin-administered wild-type and S1pr2-/- mice failed to proliferate in the presence of serum, unlike fibroblasts from saline-administered mice. The fibroblasts from bleomycin-administered mice also showed the enlarged and flattened morphology compared with fibroblasts from control mice. Bleomycin administration increased the protein expression of the cell cycle inhibitor p16INK4a in fibroblasts and the number of senescence–associated β-galactosidase (SA-β-gal)-positive fibroblasts. In S1pr2-/- fibroblasts, bleomycin administration-induced increases in p16INK4a protein expression and SA–β-gal–positive cells were augmented. Furthermore, bleomycin increased mRNA expression of interleukin-6 and matrix metalloproteinases in S1pr2-/- fibroblasts compared with wild-type fibroblasts. In addition, the activation of Akt in response to platelet–derived growth factor and S1P was enhanced in S1pr2-/- fibroblasts compared with wild-type fibroblasts. These results indicate that S1P2 deletion enhances bleomycin administration–induced cellular senescence of lung fibroblasts, which may lead to inhibition of lung fibrosis through the mechanisms involving increased matrix metalloproteinases expression. Thus, S1P2 may be a novel therapeutic target for lung fibrosis.
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| 7.
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Qia, Xun ; Okamoto, Yasuo ; Murakawa, Tomomi ; Wang, Fei ; Oyama, Osamu ; Ohkawa, Ryunosuke ; Yoshioka, Kazuaki ; Du, Wa ; Sugimoto, Naotoshi ; Yatomi, Yutaka ; Takuwa, Noriko ; Takuwa, Yoh
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金沢大学医薬保健研究域医学系<br />Therapeutic angiogenesis is a promising strategy for treating ischemia. The lysophospholipid mediato
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r sphingosine-1-phosphate (S1P) acts on vascular endothelial cells to stimulate migration and tube formation, and plays the critical role in developmental angiogenesis. We developed poly(lactic-co-glycolic-acid) (PLGA)-based S1P-containing microparticles (PLGA-S1P), which are biodegradable and continuously release S1P, and studied the effects of PLGA-S1P on neovascularization in murine ischemic hindlimbs. Intramuscular injections of PLGA-S1P stimulated blood flow in C57BL/6 mice dose-dependently, with repeated administrations at a 3-day interval, rather than a single bolus or 6-day interval, over 28. days conferring the optimal stimulating effect. In Balb/c mice that exhibit limb necrosis and dysfunction due to retarded blood flow recovery, injections of PLGA-S1P stimulated blood flow with alleviation of limb necrosis and dysfunction. PLGA-S1P alone did not induce edema in ischemic limbs, and rather blocked vascular endothelial growth factor-induced edema. PLGA-S1P not only increased the microvessel densities in ischemic muscle, but promoted coverage of vessels with smooth muscle cells and pericytes, thus stabilizing vessels. PLGA-S1P stimulated Akt and ERK with increased phosphorylation of endothelial nitric oxide synthase in ischemic muscle. The effects of the nitric oxide synthase inhibitor, Nω-nitro-l-arginine methylester, showed that PLGA-S1P-induced blood flow stimulation was partially dependent on nitric oxide. Injections of PLGA-S1P also increased the expression of angiogenic factors and the recruitment of CD45-, CD11b- and Gr-1-positive myeloid cells, which are implicated in post-ischemic angiogenesis, into ischemic muscle. These results indicate that PLGA-based, sustained local delivery of S1P is a potentially useful therapeutic modality for stimulating post-ischemic angiogenesis. © 2010 Elsevier B.V.
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Takabatake, Masayoshi ; Takuwa, Yoh ; Takuwa, Noriko ; Yasuno, Hironobu ; Matsumoto, Sayaka ; Shibutani, Makoto ; Mitsumori, Kunitoshi
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金沢大学医薬保健研究域医学系<br />We report a case of mixed epithelial and stromal tumor of the kidney (MESTK) in a 32-week-old hetero
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zygous sphingosine 1-phosphate-2 (S1P2) receptor deficient female mouse. A white solid mass replacing the left kidney was observed at the left retroperitoneal wall. Histologically, the tumor mass consisted of dimorphic cellular components of epithelial and stromal cells. Epithelial cells formed various sized irregular-shaped tubular structures resembling renal tubules surrounded by stromal cells. Immunohistochemically, epithelial cells were positive for cytokeratin, while stromal cells showed positive immunoreactivity with α-smooth muscle actin as well as vimentin. Based on the morphological and immunohistochemical findings, this tumor was diagnosed as a MESTK.
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Takuwa, Yoh ; Okamoto, Yasuo ; Yoshioka, Kazuaki ; Takuwa, Noriko
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金沢大学医薬保健研究域医学系<br />The plasma lysophospholipid mediator sphingosine-1-phosphate (S1P) is produced exclusively by sphing
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osine kinase (SPHK) 1 and SPHK2 in vivo, and plays diverse biological and pathophysiological roles by acting largely through three members of the G protein-coupled S1P receptors, S1P1, S1P2 and S1P3. S1P1 expressed on endothelial cells mediates embryonic vascular maturation and maintains vascular integrity by contributing to eNOS activation, inhibiting vascular permeability and inducing endothelial cell chemotaxis via Gi-coupled mechanisms. By contrast, S1P2, is expressed in high levels on vascular smooth muscle cells (VSMCs) and certain types of tumor cells, inhibiting Rac and cell migration via a G12/13-and Rho-dependent mechanism. In rat neointimal VSMCs, S1P1 is upregulated to mediate local production of platelet-derived growth factor, which is a key player in vascular remodeling. S1P3 expressed on endothelial cells also mediates chemotaxis toward S1P and vasorelaxation via NO production in certain vascular bed, playing protective roles for vascular integrity. S1P3 expressed on VSMCs and cardiac sinoatrial node cells mediates vasopressor and negative chronotropic effect, respectively. In addition, S1P3, together with S1P2 and SPHK1, is suggested to play a protective role against acute myocardial ischemia. However, our recent work indicates that overexpressed SPHK1 is involved in cardiomyocyte degeneration and fibrosis in vivo, in part through S1P activation of the S1P3 signaling. We also demonstrated that exogenously administered S1P accelerates neovascularization and blood flow recovery in ischemic limbs, suggesting its usefulness for angiogenic therapy. These results provide evidence for S1P receptor subtype-specific pharmacological intervention as a novel therapeutic approach to cardiovascular diseases and cancer. © 2008 Elsevier B.V. All rights reserved.
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Du, Wa ; Takuwa, Noriko ; Yoshioka, Kazuaki ; Okamoto, Yasuo ; Gonda, Koichi ; Sugihara, Kazushi ; Fukamizu, Akiyoshi ; Asano, Masahide ; Takuwa, Yoh
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金沢大学医薬保健研究域医学系<br />Sphingosine-1-phosphate (S1P) has been implicated in tumor angiogenesis by acting through the Gi-cou
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pled chemotactic receptor S1P1. Here, we report that the distinct receptor S1P2 is responsible for mediating the G12/13/Rho-dependent inhibitory effects of S1P on Akt, Rac, and cell migration, thereby negatively regulating tumor angiogenesis and tumor growth. By using S1P2LacZ/+ mice, we found that S1P2 was expressed in both tumor and normal blood vessels in many organs, in both endothelial cells (EC) and vascular smooth muscle cells, as well as in tumor-associated, CD11b-positive bone marrow-derived cells (BMDC). Lewis lung carcinoma or B16 melanoma cells implanted in S1P2-deficient (S1P2-/-) mice displayed accelerated tumor growth and angiogenesis with enhanced association of vascular smooth muscle cells and pericytes. S1P2-/- ECs exhibited enhanced Rac activity, Akt phosphorylation, cell migration, proliferation, and tube formation in vitro. Coinjection of S1P2-/- ECs and tumor cells into wild-type mice also produced a relative enhancement of tumor growth and angiogenesis in vivo. S1P2-/- mice were also more efficient at recruiting CD11b-positive BMDCs into tumors compared with wild-type siblings. Bone marrow chimera experiments revealed that S1P2 acted in BMDCs to promote tumor growth and angiogenesis. Our results indicate that, in contrast to endothelial S1P1, which stimulates tumor angiogenesis, S1P 2 on ECs and BMDCs mediates a potent inhibition of tumor angiogenesis, suggesting a novel therapeutic tactic for anticancer treatment. ©2010 AACR.
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