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971.
Tagawa Y Hiramatsu N Kasai A Hayakawa K Okamura M Yao J Kitamura M 《Free radical biology & medicine》2008,45(1):50-59
In this report, we investigated a role of endoplasmic reticulum (ER) stress in cigarette smoke (CS)-induced apoptosis of human bronchial epithelial cells (hBEC). Exposure of hBEC to CS or CS extract (CSE) caused expression of endogenous ER stress markers GRP78 and CHOP and induction of apoptosis evidenced by nuclear condensation, membrane blebbing, and activation of caspase-3 and caspase-4. In vivo exposure of mice to CS also caused induction of GRP78 and CHOP in the lung. Attenuation of ER stress by overexpression of ER chaperone GRP78 or ORP150 significantly attenuated CSE-triggered apoptosis. Exposure of hBEC to CSE caused generation of reactive oxygen species, and treatment with antioxidants inhibited CSE-induced apoptosis. Interestingly, antioxidants including a scavenger of O(2)(*-) blunted induction of CHOP by CSE without affecting the level of GRP78, and dominant-negative inhibition of CHOP abolished CSE-induced apoptosis. Furthermore, a generator of O(2)(*-) selectively induced CHOP and apoptosis in hBEC. Our results revealed that: (1) CS induces ER stress in vitro and in vivo, (2) ER stress mediates CS-triggered apoptosis downstream of oxidative stress, (3) CS-initiated apoptosis is caused through oxidative stress-dependent induction of CHOP, (4) O(2)(*-) may play a dominant role in this process, and (5) oxidative stress-independent induction of GRP78 counterbalances the proapoptotic action of CHOP. 相似文献
972.
Sitko JC Yeh B Kim M Zhou H Takaesu G Yoshimura A McBride WH Jewett A Jamieson CA Cacalano NA 《Cellular signalling》2008,20(12):2221-2230
Genotoxic agents such as ionizing radiation trigger cell cycle arrest at the G1/S and G2/M checkpoints, allowing cells to repair damaged DNA before entry into mitosis. DNA damage-induced G1 arrest involves p53-dependent expression of p21 (Cip1/Waf-1), which inhibits cyclin-dependent kinases and blocks S phase entry. While much of the core DNA damage response has been well-studied, other signaling proteins that intersect with and modulate this response remain uncharacterized. In this study, we identify Suppressor of Cytokine Signaling (SOCS)-3 as an important regulator of radiation-induced G1 arrest. SOCS3-deficient fibroblasts fail to undergo G1 arrest and accumulate in the G2/M phase of the cell cycle. SOCS3 knockout cells phosphorylate p53 and H2AX normally in response to radiation, but fail to upregulate p21 expression. In addition, STAT3 phosphorylation is elevated in SOCS3-deficient cells compared to WT cells. Normal G1 arrest can be restored in SOCS3 KO cells by retroviral transduction of WT SOCS3 or a dominant-negative mutant of STAT3. Our results suggest a novel function for SOCS3 in the control of genome stability by negatively regulating STAT3-dependent radioresistant DNA synthesis, and promoting p53-dependent p21 expression. 相似文献
973.
Ikeda N Yamada K Shibuya T Kashiwada A Matsuda K Hirata M 《Bioscience, biotechnology, and biochemistry》2008,72(5):1368-1371
Alkylphenols were effectively treated with horseradish peroxidase at pH 7.0 and 30 degrees C in the presence of H(2)O(2) and poly(ethylene glycol) irrespective of the relative position or isomeric form of the alkyl chains. Water-insoluble oligomer precipitates were readily filtered out after enzymatic treatment, and transparent and colorless solutions were obtained for all p- and m-alkylphenols used. 相似文献
974.
Yamamoto K Sato Y Ishimori A Miyairi K Okuno T Nemoto N Shimizu H Kidokoro S Hashimoto M 《Bioscience, biotechnology, and biochemistry》2008,72(8):2039-2048
D-Trigalacturonic acid methylglycoside (3) was synthesized to evaluate the previously synthesized sulfur analogue 1 by comparison. The NOE experiments revealed that both 3 and 1 took on a similar conformation around their glycosyl linkage. 相似文献
975.
Norihiro Yoshimura Hirotaka Ohara Katsuyuki Miyabe Tessin Ban Hitoshi Sano Itaru Naitoh Kazuki Hayashi Tomoaki Ando Takahiro Nakazawa Takashi Joh 《International Seminars in Surgical Oncology : ISSO》2008,5(1):19
Background
Although GIST generally occurs in the digestive tract, such as the stomach, and small and small intestine primarily, Omental GIST tumours are very rare.Case Presentation
A 63-year-old male patient, who recognized an abdominal tumor 1 year before admission, had a slight expansion of the tumor, reduction of the body and malaise, was consulted to our hospital. Abdominal CT and MRI revealed a cystic lesion of 26 cm in diameter with a clear boundary from immediately below the interseptum to the pelvic cavity, and imaged the septum and cystic wall. We considered that the patient had a cystic tumor in the abdomen, of which the primary lesion was unknown, and scheduled surgery. The patient unfortunately deteriorated with shock and sudden pain in the abdomen. Wediagnosed tumor rapture, and emergency surgery was performed. The tumor, weighing 3,600 g, was mostly cystic, and filled with sanguinous fluid and clot. Histologically, the tumor was composed of spindle cells, and was positive for c-KIT (CD117), slightly positive for alpha-smooth muscle actin (SMA), and S-100 protein positive. Based on these findings, the tumor was diagnosed as GIST primarily occurring in the greater omentum.Conclusion
We experienced a rare case of GIST which originated from the greater omentum. Recently, the prognosis of GIST has been improved since the treatment with Imatinib.It is necessary to consider the diagnosis of GIST on encountering a mass in the greater omentum.976.
Genetic variation in rice 总被引:2,自引:0,他引:2
Completion of the genomic sequencing of rice has enhanced the discovery of new genes. Wild rice relatives are good sources for extending the genetic variation of cultivated rice. Reproductive barriers are commonly found in distant crosses of rice and are attracting attention. The combination of genetic analyses and molecular tools has greatly facilitated the molecular cloning of rice genes based on the classical approach and enabled the tracking of dissemination of the alleles for domestication. Basic information for population genetics study in rice is still being collected and is expected to provide an alternative approach for finding new genes. The wide genetic variation available in wild rice relatives and the combination of various genetic approaches will allow the analysis and understanding of genetic variation at the nucleotide sequence level, as well as the discovery of novel alleles by sequence-based approaches. 相似文献
977.
The chemoprotective effect of hydroxytyrosol (HT) against Sudan I-induced genotoxicity was investigated in a human hepatoma cell line, HepG2. The comet assay and micronucleus (MN) assay were used to monitor genotoxicity. Intracellular reactive oxygen species (ROS) formation was measured using a fluorescent probe, 2,7-dichlorofluorescein diacetate (DCFH-DA). The levels of oxidative DNA damage and lipid peroxidation were estimated by immunocytochemistry analysis of 8-hydroxydeoxyguanosine (8-OHdG) and by measuring levels of thiobarbituric acid-reactive substances (TBARS), respectively. Intracellular glutathione (GSH) level was estimated by fluorometric methods. The results showed that HT significantly reduced the genotoxicity caused by Sudan I. Furthermore, HT ameliorated lipid pexidation as demonstrated by a reduction in TBARS formation and attenuated GSH depletion in a concentration-dependent manner. It was also found that HT reduced intracellular ROS formation and 8-OHdG level caused by Sudan I. These results strongly suggest that HT has significant protective ability against Sudan I-induced genotoxicity. 相似文献
978.
Tatsuya Kato Kotaro Kikuta Ayumi Kanematsu Sachiko Kondo Hirokazu Yagi Koichi Kato Enoch Y. Park 《Biotechnology letters》2017,39(9):1299-1308
Objective
To synthesize complex type N-glycans in silkworms, shRNAs against the fused lobe from Bombyx mori (BmFDL), which codes N-acetylglucosaminidase (GlcNAcase) in the Golgi, was expressed by recombinant B. mori nucleopolyhedrovirus (BmNPV) in silkworm larvae.Results
Expression was under the control of the actin promoter of B. mori or the U6-2 and i.e.-2 promoters from Orgyia pseudotsugata multiple nucleopolyhedrovirus (OpMNPV). The reduction of specific GlcNAcase activity was observed in Bm5 cells and silkworm larvae using the U6-2 promoter. In silkworm larvae, the partial suppression of BmFDL gene expression was observed. When shRNA against BmFDL was expressed under the control of U6-2 promoter, the Man3GlcNAc(Fuc)GlcNAc structure appeared in a main N-glycans of recombinant human IgG. These results suggested that the control of BmFDL expression by its shRNA in silkworms caused the modification of its N-glycan synthetic pathway, which may lead to the alteration of N-glycans in the expressed recombinant proteins.Conclusions
Suppression of BmFDL gene expression by shRNA is not sufficient to synthesize complex N-glycans in silkworm larvae but can modify the N-glycan synthetic pathway.979.
Allotetraploid cryptic species in Asplenium normale in the Japanese Archipelago,detected by chemotaxonomic and multi‐locus genotype approaches
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980.
Ayumi Mori Hiroshi Sato Megumi Kasai Tetsuya Yamada Akira Kanazawa 《Transgenic research》2017,26(3):349-362
The expression of transgenes introduced into a plant genome is sometimes suppressed by RNA silencing. Although local and systemic spread of RNA silencing have been studied, little is known about the mechanisms underlying spatial and temporal variation in transgene silencing between individual plants or between plants of different generations, which occurs seemingly stochastically. Here, we analyzed the occurrence, spread, and transmission of RNA silencing of the green fluorescent protein (GFP) gene over multiple generations of the progeny of a single soybean transformant. Observation of GFP fluorescence in entire plants of the T3–T5 generations indicated that the initiation and subsequent spread of GFP silencing varied between individuals, although this GFP silencing most frequently began in the primary leaves. In addition, GFP silencing could spread into the outer layer of seed coat tissues but was hardly detectable in the embryos. These results are consistent with the notion that transgene silencing involves its reset during reproductive phase, initiation after germination, and systemic spread in each generation. GFP silencing was absent in the pulvinus, suggesting that its cortical cells inhibit cell-to-cell spread or induction of RNA silencing. The extent of GFP silencing could differ between the stem and a petiole or between petiolules, which have limited vascular bundles connecting them and thus deter long-distant movement of silencing. Taken together, these observations indicate that the initiation and/or spread of RNA silencing depend on specific features of the architecture of the plant in addition to the mechanisms that can be conserved in higher plants. 相似文献