排序方式: 共有90条查询结果,搜索用时 15 毫秒
81.
Ko Shimamoto Chikara Miyazaki Hisako Hashimoto Takeshi Izawa Kimiko Itoh Rie Terada Yoshishige Inagaki Shigeru Iida 《Molecular & general genetics : MGG》1993,239(3):354-360
To develop an efficient gene tagging system in rice, a plasmid was constructed carrying a non-autonomous maize Ds element in the untranslated leader sequence of a hygromycin B resistance gene fused with the 35S promoter of cauliflower mosaic virus. This plasmid was cotransfected by electroporation into rice protoplasts together with a plasmid containing the maize Ac transposase gene transcribed from the 35S promoter. Five lines of evidence obtained from the analyses of hygromycin B-resistant calli, regenerated plants and their progeny showed that the introduced Ds was trans-activated by the Ac transposase gene in rice. (1) Cotransfection of the two plasmids is necessary for generation of hygromycin B resistant transformants. (2) Ds excision sites are detected by Southern blot hybridization. (3) Characteristic sequence alterations are found at Ds excision sites. (4) Newly integrated Ds is detected in the rice genome. (5) Generation of 8 by target duplications is observed at the Ds integration sites on the rice chromosomes. Our results also show that Ds can be trans-activated by the transiently expressed Ac transposase at early stages of protoplast culture and integrated stably into the rice genome, while the cotransfected Ac transposase gene is not integrated. Segregation data from such a transgenic rice plant carrying no Ac transposase gene showed that four Ds copies were stably integrated into three different chromosomes, one of which also contained the functional hph gene restored by Ds excision. The results indicate that a dispersed distribution of Ds throughout genomes not bearing the active Ac transposase gene can be achieved by simultaneous transfection with Ds and the Ac transposase gene. 相似文献
82.
Tadashi Shimizu Mitsuto Iwanaga Akio Yasunaga Yoshishige Urata Shinji Goto Shobu Shibata Takahito Kondo 《Cellular and molecular neurobiology》1998,18(3):299-310
1. Radiotherapy has attracted increasing interest in recent years. It is known that ionizing radiation induces oxygen radical injury, whereas oxidative stress by the radiation can cause cellular responses to defense cellular injury. In this study, the metabolism of antioxidants in response to ionizing radiation to the brain was studied in the brain using experimental rabbits.2. Ionizing radiation to the hemicerebrum caused an increase in the levels of glutathione (GSH) and the activity of a GSH synthesizing enzyme, -glutamylcysteine synthetase (-GCS), and Cu,Zn-superoxide dismutase (Cu,Zn-SOD). Ionizing radiation also induced DNA-damage estimated by the formation of 8-hydroxydeoxyguanosine. These changes were dependent on the radiation dose.3. Previous intrathecal-administration of buthionine sulfoximine (100 M), a specific inhibitor of -GCS, increased DNA damage by radiation in the radiated hemicerebrum. That of S-methyl GSH, on the other hand, resulted in a significant reduction of DNA damage by radiation.4. These results suggest that synthesis of GSH and Cu,Zn-SOD is responsive to ionizing radiation and this induction of antioxidants may play a role in reducing tissue damage in radiotherapy. 相似文献
83.
Shinji Goto Miho Kawakatsu Shin-ichi Izumi Yoshishige Urata Kan Kageyama Yoshito Ihara Takehiko Koji Takahito Kondo 《Free radical biology & medicine》2009,46(10):1392-1403
Glutathione S-transferases (GSTs) are multifunctional enzymes involved in the protection of cellular components against anti-cancer drugs or peroxidative stress. Previously we found that GST π, an isoform of the GSTs, is transported into the nucleus. In the present study, we found that GST π is present in mitochondria as well as in the cytosol and nucleus in mammalian cell lines. A construct comprising the 84 amino acid residues in the amino-terminal region of GST π and green fluorescent protein was detected in the mitochondria. The mutation of arginine to alanine at positions 12, 14, 19, 71, and 75 in full-length GST π completely abrogated the ability to distribute in the mitochondria, suggesting that arginine, a positively charged residue, is required for the mitochondrial transport of GST π. Chemicals generating reactive oxygen species, such as rotenone and antimycin A, decreased cell viability and reduced mitochondrial membrane potential. The overexpression of GST π diminished these changes. GST π-targeting siRNA abolished the protective effect of GST π on the mitochondria under oxidative stress. The findings indicate that the peptide signal is conducive to the mitochondrial localization of GST π under steady-state conditions without alternative splicing or posttranslational modifications such as proteolysis, suggesting that GST π protects mitochondria against oxidative stress. 相似文献
84.
Oike Y Akao M Yasunaga K Yamauchi T Morisada T Ito Y Urano T Kimura Y Kubota Y Maekawa H Miyamoto T Miyata K Matsumoto S Sakai J Nakagata N Takeya M Koseki H Ogawa Y Kadowaki T Suda T 《Nature medicine》2005,11(4):400-408
Angiopoietin-related growth factor (AGF), a member of the angiopoietin-like protein (Angptl) family, is secreted predominantly from the liver into the systemic circulation. Here, we show that most (>80%) of the AGF-deficient mice die at about embryonic day 13, whereas the surviving AGF-deficient mice develop marked obesity, lipid accumulation in skeletal muscle and liver, and insulin resistance accompanied by reduced energy expenditure relative to controls. In parallel, mice with targeted activation of AGF show leanness and increased insulin sensitivity resulting from increased energy expenditure. They are also protected from high-fat diet-induced obesity, insulin resistance and nonadipose tissue steatosis. Hepatic overexpression of AGF by adenoviral transduction, which leads to an approximately 2.5-fold increase in serum AGF concentrations, results in a significant (P < 0.01) body weight loss and increases insulin sensitivity in mice fed a high-fat diet. This study establishes AGF as a new hepatocyte-derived circulating factor that counteracts obesity and related insulin resistance. 相似文献
85.
86.
Tomohito Hirao Yoshishige Urata Kan Kageyama Midori Ikezaki Miho Kawakatsu Michiko Matsuse 《Free radical research》2013,47(11-12):957-965
Dehydroepiandrosterone (DHEA) modulates sensitivity to radiation-induced injury in human neuroglioma cells (H4) through effects on Akt signalling by glutathione (GSH)-dependent redox regulation. Previous treatment of H4 cells with DHEA for 18 h reduced the γ-ray-induced phosphorylation of Akt, activated p21waf1 synthesis and up-regulated phosphorylation of Rb independent of p53. These reactions were followed by a decrease in cell number and an increase in apoptosis and G2/M checkpoint arrest. The suppression of phosphorylation of Akt by DHEA was due to regulation of the dephosphorylation by protein phosphatase 2A (PP2A). DHEA up-regulated the expression of γ-glutamylcysteine synthetase, a rate-limiting enzyme of glutathione (GSH) synthesis, and the levels of GSH to maintain PP2A activity. The results suggested that DHEA increases the sensitivity of cells to γ-ray irradiation by inducing apoptosis and cell cycle arrest through GSH-dependent regulation of the reduced form of PP2A to down-regulate the Akt signalling pathway. 相似文献
87.
Keiji Nakamura Yoshishige Okazawa Masami Soejima Takeharu Masaki 《Bioscience, biotechnology, and biochemistry》2013,77(11):2667-2668
Two sulfur containing peptides have been isolated from a cationic peptide-rich fraction of dried Lentinus edodes by Chromatographic technic. They have been identified as γ-glutamylcystine and N,N-bis-³-glutamylcystinylglycine based on chemical, Chromatographic and spectroscopic properties. 相似文献
88.
Mitsuo Namiki Yoshishige Okazawa Akira Matsuyama 《Bioscience, biotechnology, and biochemistry》2013,77(2):108-114
The combined effects of inorganic reagents and radiation on the inactivation of E. coli in the resting state were studied. Among these reagents halides such as NaCI, KCI, KBr and KI were found to have a considerable synergistic action to radiation. Temperature effect on the halide action during irradiation was not observed, but removal of oxygen from halide solutions increased the radiosensitivity of cells. Combined effects of radiation and some other inorganic reagents were also investigated. Heavy metal salts and hydrogen peroxide were synergistic, nitrates and sulfates having no influence or a slightly protective action. Barium chloride and calcium chloride were protective in lower concentrations and synergistic in higher concentrations. These synergistic actions of inorganic reagents except ferric salts were observed during irradiation, but not after the irradiation. 相似文献
89.
Miho Kawakatsu Yoshishige Urata Ryo Imai Shinji Goto Yusuke Ono Noriyuki Nishida Tao-Sheng Li 《PloS one》2013,8(3)
Nicaraven, a chemically synthesized hydroxyl radical-specific scavenger, has been demonstrated to protect against ischemia-reperfusion injury in various organs. We investigated whether nicaraven can attenuate radiation-induced injury in hematopoietic stem/progenitor cells, which is the conmen complication of radiotherapy and one of the major causes of death in sub-acute phase after accidental exposure to high dose radiation. C57BL/6 mice were exposed to 1 Gy γ-ray radiation daily for 5 days in succession (a total of 5 Gy), and given nicaraven or a placebo after each exposure. The mice were sacrificed 2 days after the last radiation treatment, and the protective effects and relevant mechanisms of nicaraven in hematopoietic stem/progenitor cells with radiation-induced damage were investigated by ex vivo examination. We found that post-radiation administration of nicaraven significantly increased the number, improved the colony-forming capacity, and decreased the DNA damage of hematopoietic stem/progenitor cells. The urinary levels of 8-oxo-2′-deoxyguanosine, a marker of DNA oxidation, were significantly lower in mice that were given nicaraven compared with those that received a placebo treatment, although the levels of intracellular and mitochondrial reactive oxygen species in the bone marrow cells did not differ significantly between the two groups. Interestingly, compared with the placebo treatment, the administration of nicaraven significantly decreased the levels of the inflammatory cytokines IL-6 and TNF-α in the plasma of mice. Our data suggest that nicaraven effectively diminished the effects of radiation-induced injury in hematopoietic stem/progenitor cells, which is likely associated with the anti-oxidative and anti-inflammatory properties of this compound. 相似文献
90.
Yoshishige Miyabe Chie Miyabe Yoshiko Iwai Waka Yokoyama Chiyoko Sekine Kazutaka Sugimoto Masayoshi Harigai Masayuki Miyasaka Nobuyuki Miyasaka Toshihiro Nanki 《Arthritis research & therapy》2014,16(5)