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排序方式: 共有1017条查询结果,搜索用时 15 毫秒
81.
82.
Yamanaka K Tanaka M Tsutsui H Kupper TS Asahi K Okamura H Nakanishi K Suzuki M Kayagaki N Black RA Miller DK Nakashima K Shimizu M Mizutani H 《Journal of immunology (Baltimore, Md. : 1950)》2000,165(2):997-1003
To study the pathophysiological roles of overexpressed caspase-1 (CASP1), originally designated as IL-1 beta-converting enzyme, we generated transgenic mice in which human CASP1 is overexpressed in their keratinocytes. The transgenic mice spontaneously developed recalcitrant dermatitis and skin ulcers, characterized by the presence of massive keratinocyte apoptosis. The skin of the mice contained the active form of human CASP1 and expressed mRNA for caspase-activated DNase, an effector endonuclease responsible for DNA fragmentation. Their skin and sera showed elevated levels of mature IL-18 and IL-1 beta, but not of IFN-gamma. The plasma from these animals induced IFN-gamma production by IL-18-responsive NK cells. Administration of heat-killed Propionibacterium acnes, a potent in vivo type 1 cell inducer, caused IFN-gamma-mediated lethal liver injury in the transgenic mice, which was completely inhibited by treatment with neutralizing anti-IL-18 Ab. These results indicated that in vivo overexpression of CASP1 caused spontaneous apoptotic tissue injury and rendered mice highly susceptible to exogenous type 1 cell-inducing condition in collaboration with endogenously accumulated proinflammatory cytokines. 相似文献
83.
Ui M Mizutani T Takada M Arai T Ito T Murakami M Koike C Watanabe T Yoshimatsu K Iba H 《Biochemical and biophysical research communications》2000,278(1):97-105
We investigated the role of endogenous AP-1 in human tumor cell lines by introducing SupJunD-1, a dominant-negative mutant of AP-1, using vesicular stomatitis virus G protein (VSV-G)-pseudotyped retrovirus vectors. Single inoculation of six human tumor cell lines, originating from osteosarcomas, non-small cell lung carcinomas or cervical carcinomas, with recombinant SupJunD-1 virus at a high multiplicity of infection readily inhibited colony formation in soft agar. We detected no significant changes in expression levels of AP-1 components c-Jun or Fra-1, adhesion molecules CD44 or E-cadherin, or cell cycle regulator p53, which are encoded by genes previously reported to be under the control of AP-1 in some mouse or human cell lines. By varying the dosage of VSV-G-pseudotyped retrovirus, we were able to change the proviral copy number of supjunD-1 from 1 to approximately 10 and monitor suppression of endogenous AP-1 function as assessed by growth characteristics of the tumor cell lines, we found a SupJunD-1 dosage which significantly suppressed anchorage-independent growth without affecting the cellular growth in monolayer cultures at all. We conclude that endogenous AP-1 levels necessary for oncogenic activity are much higher than those sufficient to support normal growth. 相似文献
84.
SYNCRIP, a cytoplasmic counterpart of heterogeneous nuclear ribonucleoprotein R, interacts with ubiquitous synaptotagmin isoforms 总被引:7,自引:0,他引:7
Mizutani A Fukuda M Ibata K Shiraishi Y Mikoshiba K 《The Journal of biological chemistry》2000,275(13):9823-9831
Synaptotagmins (Syts) are a large family of membrane proteins consisted of at least 12 isoforms. They are categorized in neuron-specific isoforms (I-V, X, and XI) and ubiquitous isoforms (VI-IX) based on their expression patterns. Syt-I, a neuron-specific and abundant isoform, has been well characterized and postulated to be the exocytotic Ca(2+) sensor. However, the functions of other isoforms remain obscure. Here, we report that ubiquitous isoforms of synaptotagmins, Syt-VII, Syt-VIII, and Syt-IX, interacted with a cytoplasmic RNA-binding protein, SYNCRIP (Synaptotagmin-binding, cytoplasmic RNA-interacting protein), through their C2B domains. SYNCRIP was originally found in the Syt-II C2AB domain bound fraction from the mouse brain lysate. cDNA cloning of SYNCRIP cDNA revealed that the protein was highly homologous to heterogeneous nuclear ribonucleoprotein R (hnRNP R) recently identified. SYNCRIP protein was ubiquitously and constantly expressed in various tissues of mice parallel to hnRNP R. SYNCRIP indeed bound RNA with preference to poly(A) RNA; however, in contrast to the nuclear localization of hnRNP R, SYNCRIP was distributed predominantly in the cytoplasm as judged by both biochemical fractionation and immunohistochemical studies. In vitro binding experiments showed the potential interaction of SYNCRIP with C2B domains of Syts except for those of Syt-V, -VI, and -X. Furthermore, the interaction between SYNCRIP and Syt-VII, -VIII, or -IX was revealed by co-immunoprecipitation experiments using COS cells transiently expressing each Syt isoform. These findings suggested that SYNCRIP was a target of ubiquitous type of Syts and implied the involvement of ubiquitous Syts in the regulation of dynamics of the cytoplasmic mRNA. 相似文献
85.
Hasegawa J Uchiyama S Tanimoto Y Mizutani M Kobayashi Y Sambongi Y Igarashi Y 《The Journal of biological chemistry》2000,275(48):37824-37828
Mesophilic cytochrome c(551) of Pseudomonas aeruginosa (PA c(551)) became as stable as its thermophilic counterpart, Hydrogenobacter thermophilus cytochrome c(552) (HT c(552)), through only five amino acid substitutions. The five residues, distributed in three spatially separated regions, were selected and mutated with reference to the corresponding residues in HT c(552) through careful structure comparison. Thermodynamic analysis indicated that the stability of the quintuple mutant of PA c(551) could be partly attained through an enthalpic factor. The solution structure of the mutant showed that, as in HT c(552), there were tighter side chain packings in the mutated regions. Furthermore, the mutant had an increased total accessible surface area, resulting in great negative hydration free energy. Our results provide a novel example of protein stabilization in that limited amino acid substitutions can confer the overall stability of a natural highly thermophilic protein upon a mesophilic molecule. 相似文献
86.
87.
Y Kawasaki J Koike K Ijiri M Yamashita K Sugiura K Kobayashi K Seki Y Ishikawa H Mizutani J Poynter T MacCallum G Anderson 《Biological Sciences in Space》1998,12(4):373-376
Distribution of microorganisms and cellular structure of an Autonomous Biological Systems (ABS) were studied with a special attention to the effect of space environments. Viable cell densities measured by the direct fluorescence microscopic method were in the order of 10(5) cells/ml for fractions 1 (upper suspension) and 2 (lower suspension), and 10(6) cells/ml for fraction 3 (sediments). These values were 10 to 100 times larger than the values obtained by the classical colony forming unit method. No difference between flight and ground samples was observed in the vertical distribution of viable microorganisms when fractionation and analysis were carried out after recovery. Intracellular distribution of chloroplasts in higher green plants, Ceratophyllum demersum, of flight samples was disturbed after 10 days of flight (24hrs/day light on). After 4 months of flight (Mir/STS-79/81) with 24 hrs light on, Ceratophyllum demersum was completely disintegrated. On the other hand, in the second 4-months-flight experiment with 16 hrs/day light on, Ceratophyllum demersum was only slightly deteriorated. 相似文献
88.
89.
Nobukatsu Horita Kiichiro Tsuchiya Ryohei Hayashi Keita Fukushima Shuji Hibiya Masayoshi Fukuda Yoshihito Kano Tomohiro Mizutani Yasuhiro Nemoto Shiro Yui Ryuichi Okamoto Tetsuya Nakamura Mamoru Watanabe 《Biochemical and biophysical research communications》2014
Background and aims
The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour.Methods
Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence.Results
We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1 year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids.Conclusions
The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus. 相似文献90.
Atsuzawa K Nakazawa A Mizutani K Fukasawa M Yamamoto N Hashimoto T Usuda N 《Histochemistry and cell biology》2010,134(6):565-579
The presence of a mitochondrial fatty acid β-oxidation system in the retina was shown by immunohistochemistry. Fatty acids
are considered to serve as a major energy source metabolized by fatty acid β-oxidation together with glucose metabolized by
glycolysis in the organs of the entire body, but almost nothing is known about this metabolic system in the retina. Adult
rat retinae were subjected to immunofluorescence and immuno-electron microscopy for the localization of fatty acid β-oxidation
enzymes, together with western blot analysis for quantitation of the amount of enzyme proteins and DNA microarray analysis
for gene expression. All the enzymes examined were shown to be present in the retina, but in small amounts, with the amount
of protein and gene expression in the retina being about 1/10 of those in the liver. Immunohistochemistry at light and electron
microscopic levels revealed the enzymes to be more preferentially localized to the mitochondria of Müller cells than the retinal
neurons. The Müller cells were isolated from the retina and confirmed for the presence of mitochondrial fatty acid β-oxidation
enzymes. A mitochondrial fatty acid β-oxidation system was thus shown to be present in the retina heterogeneously. 相似文献