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論文

論文
Echigo, Takeshi ; Hasegawa, Minoru ; Shimada, Yuka ; Takehara, Kazuhiko ; Sato, Shinichi
出版情報: Journal of Allergy and Clinical Immunology.  113  pp.940-948,  2004-05-01.  Elsevier
URL: http://hdl.handle.net/2297/1796
概要: Background: Fractalkine (FKN) induces activation and adhesion of leukocytes expressing its receptor, CX3CR1. FKN is released from the cell surface through proteolytic cleavage as soluble FKN (sFKN). Objective: We sought to assess FKN and CX3CR1 expression in the skin, serum sFKN levels, and CX3CR1 expression on blood leukocytes in patients with atopic dermatitis (AD). Methods: FKN and CX3CR1 expression in the skin was examined immunohistochemically. mRNA expression of FKN, thymus and activation-regulated chemokine, and macrophage-derived chemokine in the skin was assessed by means of real-time RT-PCR. Serum sFKN levels were assessed by using ELISA. Blood leukocytes were stained for CX3CR1 by means of flow cytometric analysis. Results: FKN was strongly expressed on endothelial cells in skin lesions of patients with AD and psoriasis but not in normal skin. FKN mRNA levels in AD lesional skin increased to a similar extent to thymus and activation-regulated chemokine and macrophage-derived chemokine mRNA levels. CX3CR1-expressing cells in the affected skin of patients with AD or psoriasis increased compared with those in normal skin. Serum sFKN levels were increased in patients with AD but not in patients with psoriasis relative to levels in healthy control subjects. Serum sFKN levels were associated with the disease severity and decreased with the improvement of skin lesions in patients with AD. CX3CR1+ cell frequencies and CX3CR1 expression levels were decreased in CD8+ T cells, monocytes, and natural killer cells from patients with AD, but this was not observed in patients with psoriasis. Conclusions: These results suggest that through functions in both membrane-bound and soluble forms, FKN plays an important role in the trafficking of CX3CR1+ leukocytes during the inflammation caused by AD. 続きを見る
2.

論文

論文
Takuwa, Yoh ; Okamoto, Yasuo ; Yoshioka, Kazuaki ; Takuwa, Noriko
出版情報: Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids.  1781  pp.483-488,  2008-09-01.  Elsevier
URL: http://hdl.handle.net/2297/11867
概要: 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 sphingosine 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. 続きを見る
3.

論文

論文
Takuwa, Yoh ; Okamoto, Yasuo ; Yoshioka, Kazuaki ; Takuwa, Noriko
出版情報: BBA - Molecular and Cell Biology of Lipids.  781  pp.483-488,  2008-09-01.  Elsevier
URL: http://hdl.handle.net/2297/11734
概要: 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 sphingosine 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. 続きを見る
4.

論文

論文
Aung, Khin Thuzar ; Yoshioka, Kazuaki ; Aki, Sho ; Ishimaru, Kazuhiro ; Takuwa, Noriko ; Takuwa, Yoh
出版情報: Journal of Physiological Sciences.  69  pp.263-280,  2019-03-01.  Physiological Society of Japan 日本生理学会 / Springer Nature
URL: http://hdl.handle.net/2297/00053883
概要: 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 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 続きを見る
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論文

論文
高安, 達典 ; Takayasu, Tatsunori
出版情報: 平成15(2003)年度 科学研究費補助金 基盤研究(C) 研究成果報告書 = 2003 Fiscal Year Final Research Report Summary.  2002-2003  pp.111p.-,  2004-04.  金沢大学医薬保健研究域医学系
URL: http://hdl.handle.net/2297/00051045
概要: 薬毒物の毒性は致死量などで示されているが,この量と細胞死における薬毒物の濃度は一定の関係があるかどうか,血管内皮細胞を用いて,薬毒物毒性評価の可能性を研究した。血管内皮細胞を用いた細胞死の濃度は上記の4物質で各々,5,5,5及び0.1mMで あった。その他57の薬毒物についても同細胞でスクリーニングした。それらの中で毒性が最も低かったものはメタノール2Mで最も高かったものは亜砒酸で0.01mMであった。一方ヒトの推定致死量を文献で調査したところ,メタンフェタミン,コカイン,フェノバルビタール及びパラコートで各々1.3-20,7-10,14-200及び14-40mg/kgであった。この値を比較のために単位をmg/Lと置き換えると濃度になり,各々の0.007-0.1,0.02-0.03,0.06-0.9,0.05-0.16mMと計算される。メタンフェタミン,コタイン,フェノバルビタールでは1/6から1/700の低濃度で個体では死亡していた。しかし,パラコートでは略同レベルの濃度であった。同様に他の40種の薬毒物で計算し,それらの値と血管内皮細胞の細胞死した濃度を比較したところ,それらの相関係数は0.310と低い相関であった。以上,物質の個体及び細胞への毒性は個々の物質により異なることが改めて示されたが,今回の結果からは薬毒物の毒性評価を推定するまでには至らなかった。今後さらに極々の因子の検索も含め詳細に調査することが必要と考えられた。<br />Toxicity of drugs and poisons shows as lethal dose in human. In this study, relationship between the lethal dose and dose of the cell death was examined using human endothelial cells(HUVEC). Death of HUVEC judged with morphological changes in culture fluids mixed with drugs and poisons. Doses of the cell death using methamphetamine(MA), cocaine, phenobarbital(PB), paraquat(PQ) showed 5,5,5 and 0.1 mM, respectively. The other 57 drugs and poisons were screened with the same method. The most poisonous substance was arsenite sodium (0.01mM) and the least poisonous one was methanol(2M). By the references, lethal doses of human(including presumption values) in MA, cocaine, PB and PQ were 1.3-20,7-10,14-200 and 14-40mg/kg, respectively. To compare the values between lethal dose and dose of cell death, the unit made mg/L of mg/kg. The concentrations of MA, cocaine, PB and PQ were 0.007-0.1,0.002-0.003,0.06-0.9 and 0.05-0.16mM, respectively. In MA, cocaine and PB lethal doses of human showed 1/6 to 1/700 comparing to cell death of HUVEC. In PQ, however, the dose of human was same level as cell death of HUVEC. In the same manner, 49 substances were plotted between lethal dose of human and the cell death of HUVEC. When the relation line was made, the correlation coefficient(r) was 0.310, indicating poor relationship. In conclusion, morphological changes of HUVEC showed poor relationship to lethal dose of human in total 61 drugs and poisons examined. Further examination needs to determine the relationship between lethal dose and endothelial cell death in human.<br />研究課題/領域番号:14570383, 研究期間(年度):2002-2003 続きを見る