Translocation of caveolin regulates stretch-induced ERK activity in vascular smooth muscle

Kawabe, J; Okumura, S; Lee, MC; Sadoshima, J; Ishikawa, Y, AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY, 286(5), H1845-H1852, 2004. "Copyright 2004 by the American Physical Society." publisherMechanical stress contributes to vascular disease related to hypertension. Activation of ERK is key to mediating cellular proliferation and vascular remodeling in response to stretch stress. However, the mechanism by which stretch mediates ERK activation in the vascular tissue is still unclear. Caveolin, a major component of a flasklike invaginated caveolae, acts as an adaptor protein for an integrin-mediated signaling pathway. We found that cyclic stretch transiently induced translocation of caveolin from caveolae to noncaveolar membrane sites in vascular smooth muscle cells (VSMCs). This translocation of caveolin was determined by detergent solubility, sucrose gradient fractionation, and immunocytochemistry. Cyclic stretch induced ERK activation; the activity peaked at 5 min (the early phase), decreased gradually, but persisted up to 120 min (the late phase). Disruption of caveolae by methyl-β-cyclodextrin, decreasing the caveolar caveolin and accumulating the noncaveolar caveolin, enhanced ERK activation in both the early and late phases. When endogenous caveolins were downregulated, however, the late-phase ERK activation was subsided completely. Caveolin, which was translocated to noncaveolar sites in response to stretch, is associated with β_1-integrins as well as with Fyn and Shc, components required for ERK activation. Taken together, caveolin in caveolae may keep ERK inactive, but when caveolin is translocated to noncaveolar sites in response to stretch stress, caveolin mediates stretch-induced ERK activation through an association with β_1-integrins/Fyn/Shc. We suggest that stretch-induced translocation of caveolin to noncaveolar sites plays an important role in mediating stretch-induced ERK activation in VSMCs

TREM2 Expression in Schizophrenia

TREM2 and TYROBP are causal genes for Nasu–Hakola disease (NHD), a rare autosomal recessive disease characterized by bone lesions and early-onset progressive dementia. TREM2 forms a receptor signaling complex with TYROBP, which triggers the activation of immune responses in macrophages and dendritic cells, and the functional polymorphism of TREM2 is reported to be associated with neurodegenerative disorders such as Alzheimer’s disease (AD). The objective of this study was to reveal the involvement of TYROBP and TREM2 in the pathophysiology of AD and schizophrenia. Methods: We investigated the mRNA expression level of the 2 genes in leukocytes of 26 patients with AD and 24 with schizophrenia in comparison with age-matched controls. Moreover, we performed gene association analysis between these 2 genes and schizophrenia. Results: No differences were found in TYROBP mRNA expression in patients with AD and schizophrenia; however, TREM2 mRNA expression was increased in patients with AD and schizophrenia compared with controls (P < 0.001). There were no genetic associations of either gene with schizophrenia in Japanese patients. Conclusion: TREM2 expression in leukocytes is elevated not only in AD but also in schizophrenia. Inflammatory processes involving TREM2 may occur in schizophrenia, as observed in neurocognitive disorders such as AD. TREM2 expression in leukocytes may be a novel biomarker for neurological and psychiatric disorders

本学における脈管研究クラスター構築と臨床応用にむけた戦略的脈管研究の推進

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【血栓症に関するQ&A(PART6)】 薬剤 プロスタサイクリンと血管再生について教えてください

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平成25 年度「独創性のある生命科学研究」プロジェクト型研究課題 毛細血管幹細胞（Capillary Stem Cells）の再生医療応用 プロジェクト創生にむけた包括的研究活動

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Influence of Eco-driving on Fuel Consumption of Vehicles in the Following Traffic

Ecological (eco) driving features distinct driving behavior that aims at improving fuel economy of a car and consequently reducing carbon dioxide emissions. Various assistance systems have recently been developed to promote ecodriving among drivers. Through anticipation of the preceding traffic, an eco-driver smoothly regulates the velocity and headway of the car at some safe levels. Limited use of accelerator and brake often causes an eco-driven car slower than other vehicles and affects behavior of its following traffic greatly. This paper investigates the influence of eco-driving on the fuel consumption of vehicles in the following traffic. Performance of the eco-driven car and vehicles behind it are observed in various traffic flow conditions through simulation in AIMSUN microscopic traffic simulator

Vacuum Dying of Wood with High Frequency Heating (I) : On the Drying Rate, Comparing with Kiln Drying

近年,木材工業分野で注目されている高周波加熱減圧乾燥法について,二三の基礎実験を行い,つぎの結果を得た.(i)この乾燥法には,材内の水分移動を促進する二つの作用がある.すなわち,減圧下で生材を高周波加熱することにより,材内の蒸気圧を上昇させ繊維方向の水分移動を活発にする作用と,材の厚さ方向に含水率傾斜と蒸気圧傾斜を形成し,これによって水分の拡散移動を活発にする作用である.(2)前者の作用は,繊維方向気体透過性のすぐれたアピトンの乾燥で顕著な効果を発揮し,乾燥時間は熱風乾燥に比し著しく短縮され,しかもその効果は板厚や材長の影響をあまり受けない.(3)後者の作用は,期待透過性の不良なべイスギの乾燥で認めることができるが,これによる乾燥時間の短縮は比較的少ない.Recently, vacuum drying method combined high frequency heating has been applied to a certain extent in the field of wood industry. The purpose of this work is to obtain some fundamental information about the drying rate in this methord comparing with that in conventional kiln drying method. Green boards and dimention lumbers from the three kinds of wood species were used for the test material: Apitong (very high permeable wood), Matoa (less permeable wood) and Western redcedar (very low permeable wood). Some specimens were covered with thick epoxy-resin films on their cross sections or the other four faces to control water evaporation from the specimens. Vacuum drying was done in the vacuum drier under 30 or 40 mmHg and the test specimens were heated up to 40℃ with high frequency (6.7 MHz, 4000 V, 0.2 A). Kiln drying was performed in the oven drier basing upon the standard drying schedules used in Japan. The results obtained are summarized as follows. (1) The drying time for green board is reduced remarkably or slightly by application of high frequency heating-vacuum method comparing with drying time by kiln method. The reducing ratio is 1/13 for Apitong, 1/2.6 for Western redcedar and 1/1.4 for Matoa, and the efficiency of this method on drying time depends on wood species. (2) Based on the experimental results on the evaporating rates, it is considered that there are two principal effects on the moisture movement in high frequency heating-vacuum drying, that is, one is the promotional effect of the vapor pressure difference between inside and outside of specimen on the moisture movement in the vessels along fiber direction as observed in the case of Apitong, and the other is the accelerating effect of the moisture and pressure gradient on moisture diffuse from inside to outside of the specimen perpendicular to fiber direction as observed in the case of Western redcedar. (3) In air drying, the drying time does not depend on board length except under 0.5 m. But in high frequency hea ting-vacuum drying, the time varies slightly or greatly with board length depending on wood species. For instance, the drying time for a board of 1 m length increases by approximately 2 times that for 10 cm length in the case of Apitong, and about 10 times in the case of Western redcedar. (4) Although the drying time for boards and dimension lumbers in kiln drying increases exponentially with increasing their thickness, the time in high frequency heating-vacuum drying increases slightly with increasing thickness. For instance, the drying time for a dimention lumber of 10 cm thickness is about 2.5 times as long as that for a board of 1 cm thickness in the case of Apitong, and about 8 times in the case of Western redcedar