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241.
Asako Saiki Yasuaki Ishida Ryuichi Hirota Takeshi Nakamura Akio Kuroda 《Bioscience, biotechnology, and biochemistry》2016,80(5):955-961
Inorganic polyphosphate (polyP) was previously identified as a probiotic-derived substance that enhances intestinal barrier function. PolyP-accumulating bacteria are expected to have beneficial effects on the human gastrointestinal tract. In this study, we selected Lactobacillus paracasei JCM 1163 as a strain with the potential to accumulate polyP, because among the probiotic bacteria stored in our laboratory, it had the largest amount of polyP. The chain length of polyP accumulated in L. paracasei JCM 1163 was approximately 700 phosphate (Pi) residues. L. paracasei JCM 1163 accumulated polyP when Pi was added to Pi-starved cells. We further improved the ability of L. paracasei JCM 1163 to accumulate polyP by nitrosoguanidine mutagenesis. The mutant accumulated polyP at a level of 1500 nmol/mg protein—approximately 190 times that of the wild-type strain. PolyP extracted from the L. paracasei JCM 1163 significantly suppressed the oxidant-induced intestinal permeability in mouse small intestine. In conclusion, we have succeeded in breeding the polyP-accumulating Lactobacillus mutant that is expected to enhance intestinal barrier function. 相似文献
242.
Clathrin-mediated endocytosis involves a coordinated series of molecular events regulated by interactions among a variety of proteins and lipids through specific domains. One such domain is the Eps15 homology (EH) domain, a highly conserved protein-protein interaction domain present in a number of proteins distributed from yeast to mammals. Several lines of evidence suggest that the yeast EH domain-containing proteins Pan1p, End3p, and Ede1p play important roles during endocytosis. Although genetic and cell-biological studies of these proteins suggested a role for the EH domains in clathrin-mediated endocytosis, it was unclear how they regulate clathrin coat assembly. To explore the role of the EH domain in yeast endocytosis, we mutated those of Pan1p, End3p, or Ede1p, respectively, and examined the effects of single, double, or triple mutation on clathrin coat assembly. We found that mutations of the EH domain caused a defect of cargo internalization and a delay of clathrin coat assembly but had no effect on assembly of the actin patch. We also demonstrated functional redundancy among the EH domains of Pan1p, End3p, and Ede1p for endocytosis. Of interest, the dynamics of several endocytic proteins were differentially affected by various EH domain mutations, suggesting functional diversity of each EH domain. 相似文献
243.
244.
During the induction of plasticity of dendritic spines, many intracellular signaling pathways are spatially and temporally regulated to co-ordinate downstream cellular processes in different dendritic micron-domains. Recent advent of imaging technology based on fluorescence resonance energy transfer (FRET) has allowed the direct monitoring of the spatiotemporal regulation of signaling activity in spines and dendrites during synaptic plasticity. In particular, the activity of three small GTPase proteins HRas, Cdc42, and RhoA, which share similar structure and mobility on the plasma membrane, displayed different spatial spreading patterns: Cdc42 is compartmentalized in the stimulated spines while RhoA and HRas spread into dendrites over 5-10 μm. These measurements thus provide the basis for understanding the mechanisms underlying the spatiotemporal regulation of signaling activity. Further, using spatiotemporally controlled spine stimulations, some of the roles of signal spreading have been revealed. 相似文献
245.
Nguyen TT Kanaori K Hojo MK Kawada T Yamaoka R Akino T 《Bioscience, biotechnology, and biochemistry》2011,75(9):1818-1822
We identified the soldier-specific compounds in the Japanese subterranean termite, Reticulitermes speratus, to clarify their ethological roles. Silica gel column chromatography separated one major soldier-specific compound in the hexane fraction accounting for 70-80% of the total amount of the fraction, while cuticular hydrocarbons constituted the rest. We identified the compound as β-selinene by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy. Comparative GC analyses of the major exocrine glands detected the compound in the soldier's frontal gland. Both soldiers and workers made aggregation to the hexane fraction, as well as to the crushed heads and head extract of the soldiers. They did not aggregate to cuticular hydrocarbons, making it likely that β-selinene was the aggregation pheromone in this species. The opportunistic predator of this termite, Lasius japonicus, was also attracted to the compounds. The ant workers, therefore, would use the termite aggregation pheromone as a kairomone for hunting them. 相似文献
246.
Ueno R Hamada-Sato N Ishida M Urano N 《Bioscience, biotechnology, and biochemistry》2011,75(9):1654-1661
Apart from Xanthophyllomyces dendrorhous, pink colony-forming yeasts have not been examined as a pigmentation source in captive animals. In this study, aquatic yeasts were screened with a view to abundances of carotenoids. Phylogenetic analyses of these caroetnoid-rich yeasts based on large subunit ribosomal RNA gene (LSU rDNA) partial sequences showed that all belonged to the order Sporidiobolales. Both the qualitative and the quantitative differences in carotenoids between the yeasts appeared to be consistent with their phylogenetic affiliations. This information might be useful in the selection of pigment-rich yeasts containing specific carotenoids from a large number of strains. We also found, for the first time, the potential of a pigment-rich Rhodotorula strain as a colorant for aquaculture. The integuments of tilapia and carp fed the alkali-treated cells of strain Rhodotorula dairenensis Sag 17 were pigmented after 3 months of cultivation. The fish integuments retained the yeast carotenes shortly after the start of feeding, and were converted to the fish-specific xanthophylls in vivo. 相似文献
247.
Onomoto K Morimoto S Kawaguchi T Toyoda H Tanaka M Kuroda M Uno K Kumada T Matsuda F Shimotohno K Fujita T Murakami Y 《PloS one》2011,6(5):e19799
Background
Despite being expensive, the standard combination of pegylated interferon (Peg-IFN)- α and ribavirin used to treat chronic hepatitis C (CH) results in a moderate clearance rate and a plethora of side effects. This makes it necessary to predict patient outcome so as to improve the accuracy of treatment. Although the antiviral mechanism of genetically altered IL28B is unknown, IL28B polymorphism is considered a good predictor of IFN combination treatment outcome.Methodology
Using microarray, we quantified the expression profile of 237 IFN related genes in 87 CH liver biopsy specimens to clarify the relationship between IFN pathway and viral elimination, and to predict patients'' clinical outcome. In 72 out of 87 patients we also analyzed IL28B polymorphism (rs8099917).Principal Findings
Five IFN related-genes (IFI27, IFI 44, ISG15, MX1, and OAS1) had expression levels significantly higher in nonresponders (NR) than in normal liver (NL) and sustained virological responders (SVR); this high expression was also frequently seen in cases with the minor (TG or GG) IL28B genotype. The expression pattern of 31 IFN related-genes also differed significantly between NR and NL. We predicted drug response in NR with 86.1% accuracy by diagonal linear discriminant analysis (DLDA).Conclusion
IFN system dysregulation before treatment was associated with poor IFN therapy response. Determining IFN related-gene expression pattern based on patients'' response to combination therapy, allowed us to predict drug response with high accuracy. This method can be applied to establishing novel antiviral therapies and strategies for patients using a more individual approach. 相似文献248.
Noguchi T Miyachi H Katayama R Naito M Hashimoto Y 《Bioorganic & medicinal chemistry letters》2005,15(13):3212-3215
5-Hydroxy- and 4-amino-2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione (5HPP-33 and 4APP-33, respectively) have been shown to possess cell differentiation-inducing activity toward human leukemia cell line HL-60. 相似文献
249.
To elucidate the hidden dynamics of extracellular-signal-regulated kinase (ERK) signalling networks, we developed a simulation model of ERK signalling networks by constraining in silico dynamics based on in vivo dynamics in PC12 cells. We predicted and validated that transient ERK activation depends on rapid increases of epidermal growth factor and nerve growth factor (NGF) but not on their final concentrations, whereas sustained ERK activation depends on the final concentration of NGF but not on the temporal rate of increase. These ERK dynamics depend on Ras and Rap1 dynamics, the inactivation processes of which are growth-factor-dependent and -independent, respectively. Therefore, the Ras and Rap1 systems capture the temporal rate and concentration of growth factors, and encode these distinct physical properties into transient and sustained ERK activation, respectively. 相似文献
250.
Kondo S Kagami S Urushihara M Kitamura A Shimizu M Strutz F Müller GA Kuroda Y 《Biochimica et biophysica acta》2004,1693(2):91-100
Renal tubulointerstitial fibrosis is the common final pathway leading to end-stage renal failure. Tubulointerstitial fibrosis is characterized by fibroblast proliferation and excessive matrix accumulation. Transforming growth factor-beta1 (TGF-beta1) has been implicated in the development of renal fibrosis accompanied by alpha-smooth muscle actin (alpha-SMA) expression in renal fibroblasts. To investigate the molecular and cellular mechanisms involved in tubulointerstitial fibrosis, we examined the effect of TGF-beta1 on collagen type I (collagen) gel contraction, an in vitro model of scar collagen remodeling. TGF-beta1 enhanced collagen gel contraction by human renal fibroblasts in a dose- and time-dependent manner. Function-blocking anti-alpha1 or anti-alpha2 integrin subunit antibodies significantly suppressed TGF-beta1-stimulated collagen gel contraction. Scanning electron microscopy showed that TGF-beta1 enhanced the formation of the collagen fibrils by cell attachment to collagen via alpha1beta1 and alpha2beta1 integrins. Flow cytometry and cell adhesion analyses revealed that the stimulation of renal fibroblasts with TGF-beta1 enhanced cell adhesion to collagen via the increased expression of alpha1 and alpha2 integrin subunits within collagen gels. Fibroblast migration to collagen was not up-regulated by TGF-beta1. Furthermore, TGF-beta1 increased the expression of a putative contractile protein, alpha-SMA, by human renal fibroblasts in collagen gels. These results suggest that TGF-beta1 stimulates fibroblast-collagen matrix remodeling by increasing both integrin-mediated cell attachment to collagen and alpha-SMA expression, thereby contributing to pathological tubulointerstitial collagen matrix reorganization in renal fibrosis. 相似文献