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排序方式: 共有659条查询结果,搜索用时 15 毫秒
631.
Blockage of Ca(2+)-permeable AMPA receptors suppresses migration and induces apoptosis in human glioblastoma cells 总被引:7,自引:0,他引:7
Ishiuchi S Tsuzuki K Yoshida Y Yamada N Hagimura N Okado H Miwa A Kurihara H Nakazato Y Tamura M Sasaki T Ozawa S 《Nature medicine》2002,8(9):971-978
Glioblastoma multiforme is the most undifferentiated type of brain tumor, and its prognosis is extremely poor. Glioblastoma cells exhibit highly migratory and invasive behavior, which makes surgical intervention unsuccessful. Here, we showed that glioblastoma cells express Ca(2+)-permeable alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)-type glutamate receptors assembled from the GluR1 and/or GluR4 subunits, and that their conversion to Ca(2+)-impermeable receptors by adenovirus-mediated transfer of the GluR2 cDNA inhibited cell locomotion and induced apoptosis. In contrast, overexpression of Ca(2+)-permeable AMPA receptors facilitated migration and proliferation of the tumor cells. These findings indicate that Ca(2+)-permeable AMPA receptors have crucial roles in growth of glioblastoma. Blockage of these Ca(2+)-permeable receptors may be a useful therapeutic strategy for the prevention of glioblastoma invasion. 相似文献
632.
Vacuolar proton pumps and aquaporins involved in rapid internode elongation of deepwater rice 总被引:1,自引:0,他引:1
Muto Y Segami S Hayashi H Sakurai J Murai-Hatano M Hattori Y Ashikari M Maeshima M 《Bioscience, biotechnology, and biochemistry》2011,75(1):114-122
Rapid growth of the submerged shoots of deepwater rice is essential for survival during the rainy season. We investigated changes in the expression of vacuolar H(+)-ATPase (V-ATPase), H(+)-pyrophosphatase (V-PPase), and aquaporins under submerged conditions. The amounts of vacuolar proton pumps, which support the active transport of ions into the vacuoles, were maintained on a membrane protein basis in the developing vacuoles. Among the six isogenes of V-PPase, OsVHP1;3 was markedly enhanced by submersion. The gene expression of efficient water channels, OsTIP1;1, OsTIP2;2, OsPIP1;1, OsPIP2;1, and OsPIP2;2, was markedly enhanced by submersion. The increase in aquaporin expression might support quick elongation of internodes. The mRNA levels of OsNIP2;2 and OsNIP3;1, which transport silicic and boric acids respectively, clearly decreased. The present study indicates that internodes of deepwater rice upregulate vacuolar proton pumps and water channel aquaporins and downregulate aquaporins that allow permeation of the substrates that suppress internode growth. 相似文献
633.
Masaki Ogata Yuta Ota Takaji Matsutani Masanobu Nanno Ryuji Suzuki Tsunetoshi Itoh 《Cell and tissue research》2013,352(2):287-300
We previously found that an i.p. injection of anti-CD3 monoclonal antibody (mAb) into mice caused DNA fragmentation in the intestinal villous epithelial cells (IVECs) of the duodenum and the jejunum. In this study, in order to elucidate the mechanism of DNA fragmentation in IVECs, we searched for the inducer(s) of DNA fragmentation by using immunohistochemistry. The release of cytoplasmic granules from intraepithelial lymphocytes (IELs) and the formation of large gaps between IELs and IVECs were observed electron microscopically after antibody administration. The presence and distribution pattern of Granzyme B (GrB), a serine protease in cytolytic granules present in cytotoxic T lymphocytes and natural killer cells and considered to be the responsible molecule for DNA fragmentation in target cells, was examined in detail in intestinal villi by immunohistology. GrB was detected in cytoplasmic granules in nearly all IELs. The time-kinetics of granule release from IELs after mAb injection coincided not only with that of the extracellular diffusion of GrB, but also with that of DNA fragmentation in IVECs. On the other hand, perforin (Pfn), assumed to cooperate with GrB in DNA fragmentation, could not be detected in IELs, and its release was not confirmed after the anti-CD3 mAb injection. Anti-CD3 mAb injection also induced DNA fragmentation in IVECs in Pfn-knockout mice. These results support the notion that DNA fragmentation in IVECs by the stimulated IELs in the present study is induced by a mechanism involving GrB, but independent of Pfn. 相似文献
634.
635.
Yuhei Tazunoki Kasumi Akashi Sumire Haramoto Akihito Kita Yukari Mochioka Hiroki Matsuda Kazuki Ohta Makoto Tokuda 《Journal of fish biology》2021,99(6):1822-1831
In recent years, the biodiversity of freshwater fishes has been markedly decreasing worldwide because of anthropogenic activities. The Japanese striped loach, Cobitis kaibarai (Cypriniformes: Cobitidae), is a primary freshwater fish endemic to northern Kyushu, Japan. This species is designated as endangered IB class in the Red List by the Japan Ministry of the Environment. Its population is decreasing, possibly because of habitat loss and degradation. To conserve C. kaibarai populations, information on its basic ecology is necessary; nonetheless, its detailed life history and reproductive ecology have yet to be clarified. In this study, the authors conducted monthly capture–mark–recapture surveys and periodical observations to investigate the life history, spawning sites and season of C. kaibarai. They also evaluated the influence of creek reshaping (concrete revetment) on the C. kaibarai population in Saga Plain, northern Kyushu. Between 2015 and 2018, more individuals were captured during winter than summer. The average body width of females peaked in early June and small immatures were confirmed from July. Some individuals were captured across 15 or more months after their initial marking. In the survey of reproductive sites, eggs and larvae of C. kaibarai were found in shallow areas in mid-June; these were temporarily submerged following the increase in water level from early June. Therefore, C. kaibarai spawns in shallow areas during this season. Based on the capture–mark–recapture surveys, the estimated population density of C. kaibarai significantly decreased in a census site that had undergone creek reshaping, which contrasted with the results in a control site, where no significant difference was detected. The standard length of C. kaibarai increased following creek reshaping, suggesting that the proportion of C. kaibarai postponing spawning had increased, possibly because of degradation of spawning environments. The results of this study provide important ecological knowledge for the conservation of C. kaibarai and emphasize the importance of shallow waters for floodplain spawners. 相似文献
636.
Enokizu Akiko Morisaka Tadamichi Handa Yukari Yoshioka Motoi 《Journal of Ethology》2022,40(1):103-108
Journal of Ethology - Yawning is an involuntary action that occurs in three phases: (1) slow mouth opening accompanied by inhalation, (2) maintaining the maximum mouth size, and (3) quick closure... 相似文献
637.
Tomoko Satake Atsushi Suzuki Tomoko Satake Kazunari Yamashita Kenji Hayashi Satoko Miyatake Miwa Tamura-Nakano Hiroshi Doi Yasuhide Furuta Go Shioi Eriko Miura Yukari H Takeo Kunihiro Yoshida Hiroyuki Yahikozawa Naomichi Matsumoto Michisuke Yuzaki Atsushi Suzuki 《The EMBO journal》2017,36(9):1227-1242
The axon initial segment (AIS) is a specialized domain essential for neuronal function, the formation of which begins with localization of an ankyrin-G (AnkG) scaffold. However, the mechanism directing and maintaining AnkG localization is largely unknown. In this study, we demonstrate that in vivo knockdown of microtubule cross-linking factor 1 (MTCL1) in cerebellar Purkinje cells causes loss of axonal polarity coupled with AnkG mislocalization. MTCL1 lacking MT-stabilizing activity failed to restore these defects, and stable MT bundles spanning the AIS were disorganized in knockdown cells. Interestingly, during early postnatal development, colocalization of MTCL1 with these stable MT bundles was observed prominently in the axon hillock and proximal axon. These results indicate that MTCL1-mediated formation of stable MT bundles is crucial for maintenance of AnkG localization. We also demonstrate that Mtcl1 gene disruption results in abnormal motor coordination with Purkinje cell degeneration, and provide evidence suggesting possible involvement of MTCL1 dysfunction in the pathogenesis of spinocerebellar ataxia. 相似文献
638.
Yukari Kakita Nobuhiro Kashige Kunihiko Murata Ataru Kuroiwa Michiko Funatsu Kenji Watanabe 《Microbiology and immunology》1995,39(8):571-576
The effect of microwave irradiation on the survival of bacteriophage PL-1, which is specific for Lactobacillus casei, was studied using a commercial 2,450 MHz microwave oven. The phages were inactivated by microwave irradiation according to almost first-order reaction kinetics. The rate of phage inactivation was not affected by the difference in the continuous or intermittent irradiation, nor by the concentrations of phages used, but was affected by the volume of phage suspensions, which prevented the loss of generated heat. Microwave irradiation of phage suspensions produced a number of ghost phages with empty heads, but fragmentation of the tail was hardly noticed. The breakage of phage genome DNA was primarily caused by the heat generated by microwave irradiation, whereas the phage DNA was not affected by the same temperature achieved by heat from outside. Thus we concluded that the phage-inactivating effect of microwave irradiation was mainly attributed to a thermal microwave effect, which was much stronger than a simple thermal exposure. 相似文献
639.
Yukari Ohta Madoka Katsumata Kanako Kurosawa Yoshihiro Takaki Hiroshi Nishimura Takashi Watanabe Ken-ichi Kasuya 《Environmental microbiology》2021,23(8):4151-4167
Microbial decomposition of allochthonous plant components imported into the aquatic environment is one of the vital steps of the carbon cycle on earth. To expand the knowledge of the biodegradation of complex plant materials in aquatic environments, we recovered a sunken wood from the bottom of Otsuchi Bay, situated in northeastern Japan in 2012. We isolated Sphingobium with high ferulic acid esterase activity. The strain, designated as OW59, grew on various aromatic compounds and sugars, occurring naturally in terrestrial plants. A genomic study of the strain suggested its role in degrading hemicelluloses. We identified a gene encoding a non-secretory tannase-family α/β hydrolase, which exhibited ferulic acid esterase activity. This enzyme shares the consensus catalytic triad (Ser-His-Asp) within the tannase family block X in the ESTHER database. The molecules, which had the same calculated elemental compositions, were produced consistently in both the enzymatic and microbial degradation of rice straw crude extracts. The non-secretory tannase-family α/β hydrolase activity may confer an important phenotypic feature on the strain to accelerate plant biomass degradation. Our study provides insights into the underlying biodegradation process of terrestrial plant polymers in aquatic environments. 相似文献
640.
Yukari H. Takeo S. Andrew Shuster Linnie Jiang Miley C. Hu David J. Luginbuhl Thomas Rülicke Ximena Contreras Simon Hippenmeyer Mark J. Wagner Surya Ganguli Liqun Luo 《Neuron》2021,109(4):629-644.e8
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