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排序方式: 共有1033条查询结果,搜索用时 15 毫秒
981.
Takasawa S Ikeda T Akiyama T Nata K Nakagawa K Shervani NJ Noguchi N Murakami-Kawaguchi S Yamauchi A Takahashi I Tomioka-Kumagai T Okamoto H 《FEBS letters》2006,580(2):585-591
Regenerating gene product (Reg) is induced in pancreatic beta-cells and acts as an autocrine/paracrine growth factor for regeneration via a cell surface Reg receptor. However, the manner by which Reg induces beta-cell regeneration was unknown. In the present study, we found that Reg increased phospho-ATF-2, which binds to -57 to -52 of the cyclin D1 gene to activate the promoter. The Reg/ATF-2-induced cyclin D1 promoter activation was attenuated by PI(3)K inhibitors such as LY294002 and wortmannin. In Reg knockout mouse islets, the levels of phospho-ATF-2, cyclin D1, and phospho-Rb were greatly decreased. These results indicate that the Reg-Reg receptor system stimulates the PI(3)K/ATF-2/cyclin D1 signaling pathway to induce beta-cell regeneration. 相似文献
982.
Hirata Y Inagaki H Shimizu T Li Q Nagahara N Minami M Kawada T 《Archives of biochemistry and biophysics》2006,446(1):35-43
Human granzyme 3 (Gr3) is a serine protease contained in the granules of natural killer cells and cytotoxic T lymphocytes. To elucidate the biochemical and physiological characteristics of Gr3, we attempted to prepare an enzymatically active recombinant human Gr3 without refolding and proteolytic activation. An expression vector was constructed, in which the pre-/pro-peptide coding sequence of Gr3 was replaced with the bacterial pelB leader sequence. The resultant expression product was a fully active protease in the periplasmic fraction of Escherichia coli and was purified to homogeneity. The purified enzyme effectively hydrolyzed Z-Lys-SBzl, a conventionally used substrate of Gr3. In addition, it also hydrolyzed the peptide substrate library FRETS-25Xaa series, required basic amino acid residues, Arg or Lys, at the P1 position, and most efficiently hydrolyzed the carboxylic side of Phe-Tyr-Arg downward arrow (P3-P2-P1) sequence of the 475 tripeptide combinations. 相似文献
983.
Sato T Fujita N Yamada A Ooshio T Okamoto R Irie K Takai Y 《The Journal of biological chemistry》2006,281(8):5288-5299
The Ca2+-independent immunoglobulin-like molecule nectin first forms cell-cell adhesion and then assembles cadherin at nectin-based cell-cell adhesion sites, resulting in the formation of adherens junctions (AJs). Afadin is a nectin- and actin filament-binding protein that connects nectin to the actin cytoskeleton. Here, we studied the roles and modes of action of nectin and afadin in the formation of AJs in cultured MDCK cells. The trans-interaction of nectin assembled E-cadherin, which associated with p120(ctn), beta-catenin, and alpha-catenin, at the nectin-based cell-cell adhesion sites in an afadin-independent manner. However, the assembled E-cadherin showed weak cell-cell adhesion activity and might be the non-trans-interacting form. This assembly was mediated by the IQGAP1-dependent actin cytoskeleton, which was organized by Cdc42 and Rac small G proteins that were activated by the action of trans-interacting nectin through c-Src and Rap1 small G protein in an afadin-independent manner. However, Rap1 bound to afadin, and this Rap1-afadin complex then interacted with p120(ctn) associated with non-trans-interacting E-cadherin, thereby causing the trans-interaction of E-cadherin. Thus, nectin regulates the assembly and cell-cell adhesion activity of E-cadherin through afadin, nectin signaling, and p120(ctn) for the formation of AJs in Madin-Darby canine kidney cells. 相似文献
984.
Cardiovascular malformations with normal smooth muscle differentiation in neural crest-specific type II TGFbeta receptor (Tgfbr2) mutant mice 总被引:1,自引:0,他引:1
Previous studies have demonstrated that TGFbeta induces a smooth muscle fate in primary neural crest cells in culture. By crossing a conditional allele of the type II TGFbeta receptor with the neural crest-specific Wnt1cre transgene, we have addressed the in vivo requirement for TGFbeta signaling in smooth muscle specification and differentiation. We find that elimination of the TGFbeta receptor does not alter neural crest cell specification to a smooth muscle fate in the cranial or cardiac domains, and that a smooth muscle fate is not realized by trunk neural crest cells in either control or mutant embryos. Instead, mutant embryos exhibit with complete penetrance two very specific and mechanistically distinct cardiovascular malformations--persistent truncus arteriosus (PTA) and interrupted aortic arch (IAA-B). Pharyngeal organ defects such as those seen in models of DiGeorge syndrome were not observed, arguing against an early perturbation of the cardiac neural crest cell lineage. We infer that TGFbeta is an essential morphogenic signal for the neural crest cell lineage in specific aspects of cardiovascular development, although one that is not required for smooth muscle differentiation. 相似文献
985.
Terufumi Takagi Hideaki Nojiri Takako Yoshida Hiroshi Habe Toshio Omori 《Biotechnology letters》2002,24(24):2099-2106
The preferred substrates in angular dioxygenation, monooxygenation, and lateral dioxygenation by dibenzofuran 4,4a-dioxygenase (DFDO) from Terrabacter sp. strain DBF63 and carbazole 1,9a-dioxygenase (CARDO) from Pseudomonas resinovorans strain CA10 are shown to be distinctly different. The preferred oxygenation reactions suggest that DFDO evolved from a polycyclic aromatic hydrocarbon dioxygenase and that its most preferred substrates were fluorene and 9-fluorenone. The angular dioxygenases involved in the degradation pathway of dibenzofuran (dioxin) and fluorene are closely related in function, while CARDO is a novel enzyme not only phylogenetically but also functionally. 相似文献
986.
Junichiro Miyazaki Keiichi Ito Tomonobu Fujita Yuriko Matsuzaki Takako Asano Masamichi Hayakawa Tomohiko Asano Yutaka Kawakami 《Translational oncology》2017,10(2):142-152
Renal cell carcinoma (RCC) is the most lethal urological malignancy with high risk of recurrence; thus, new prognostic biomarkers are needed. In this study, a new RCC antigen, PTPL1 associated RhoGAP1 (PARG1), was identified by using serological identification of recombinant cDNA expression cloning with sera from RCC patients. PARG1 protein was found to be differentially expressed in RCC cells among patients. High PARG1 expression is significantly correlated with various clinicopathological factors relating to cancer cell proliferation and invasion, including G3 percentage (P = .0046), Ki-67 score (p expression is also correlated with high recurrence of N0M0 patients (P = .0084) and poor prognosis in RCC patients (P = .0345). Multivariate analysis has revealed that high PARG1 expression is an independent factor for recurrence (P = .0149) of N0M0 RCC patients. In in vitro studies, depletion of PARG1by siRNA in human RCC cell lines inhibited their proliferation through inducing G1 cell cycle arrest via upregulation of p53 and subsequent p21Cip1/Waf1, which are mediated by increased RhoA-ROCK activities. Similarly, PARG1 depletion cells inhibited invasion ability via increasing RhoA-ROCK activities in the RCC cell lines. Conversely, overexpression of PARG1 on human embryonic kidney cell line HEK293T promotes its cell proliferation and invasion. These results indicate that PARG1 plays crucial roles in progression of human RCC in increasing cell proliferation and invasion ability via inhibition of the RhoA-ROCK axis, and PARG1 is a poor prognostic marker, particularly for high recurrence of N0M0 RCC patients. 相似文献
987.
988.
Antifungal pharmacodynamic characteristics of amphotericin B against Trichosporon asahii, using time-kill methodology 总被引:3,自引:0,他引:3
We determined the MIC of amphotericin B against 45 Trichosporon asahii isolates from various clinical and environmental sources, and used in vitro time-kill methods to characterize the relationship between amphotericin B concentrations and MIC for four representative T. asahii isolates. Amphotericin B had concentration-dependent antifungal activity. MICs ranged from 0.5 to 16 microg/ml, and most T. asahii isolates (76%, 34/45) were inhibited at safely achievable amphotericin B serum concentrations (< or = 2 microg/ml). However, 40% (18/45) of isolates were not killed at these concentrations (MFCs from 1.0 to 32 microg/ml). At concentrations > or = 2 x MIC, amphotericin B exhibited fungicidal activity (< 99.9% reduction in CFU) over a 12-hr time-period; the maximal effect was achieved at > or =4 x MIC. Susceptibility testing confirmed the resistance of T. asahii to amphotericin B, and in vitro pharmacodynamic results also suggest that amphotericin B is not suitable therapy for T. asahii infection. 相似文献
989.
990.
Analysis of intestinal flora of a patient with congenital absence of the portal vein 总被引:2,自引:0,他引:2
S. Kamiya Izumi Taniguchi Takako Yamamoto S. Sawamura M. Kai N. Ohnishi M. Tsuda M. Yamamura H. Nakasaki S. Yokoyama T. Mitomi A. Ozawa 《FEMS immunology and medical microbiology》1993,7(1):73-80
Abstract A 14-year-old female patient, admitted for a closer examination of liver tumour (hepatocellular adenoma), was diagnosed as having a congenital absence of the portal vein. The blood ammonia level (approximately 120 μg dl−1 ) in the superior mesenteric vein was markedly low compared to the normal value of 300–350 μg dl−1 in the portal vein. The decreased ammonia concentration and urease activity of the patient's faeces were demonstrated. The dominant intestinal flora in the faeces of the patient, before operation, was Bifidobacterium sp., Bifidobacterium breve, Bifidobacterium lonqum, Lactobacillus plantarum , and after the operation Bacteroides vulgatus, Veillonella parvula, Peptococcus magnus Bifidobacterium longum . In contrast, Bifidobacterium bifidum, Bacteroides ureolyticus, Bacteroides ovatus and Bacteroides distasonis, B. ovatus, Bifidobacterium adolescentis were dominant flora in the faeces of two healthy volunteers, respectively. Among microorganisms isolated from the patient, Morganella morganii, Candida sp., Eubacterium aerofacience and Eubacterium rectale were strongly positive in urease activity in vitro; Streptococcus mitior, Staphylococcus intermedius, Micrococcus kristinae, Selenomonas ruminantum, Bacteroides ureolyticus and Lactobacillus casei ss. pseudoplantarum from the healthy volunteers. These results imply the homeostatic regulation system of faecal ammonia concentration by urease-producing microorganisms in the patient. 相似文献