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951.
Xu X Chen Z Zhao X Wang J Ding D Wang Z Tan F Tan X Zhou F Sun J Sun N Gao Y Shao K Li N Qiu B He J 《Biochemical and biophysical research communications》2012,421(4):640-645
MicroRNAs (miRNAs) as a species of small non coding single stranded RNA of about 21-25 nucleotides have important roles in the development of different cancers. In present study, we found that the expression of miR-25 was up-regulated in 60 esophageal squamous cell carcinoma (ESCC) tissues compared with matched adjacent non-cancer tissues. Moreover, we demonstrated that the up-regulation of miR-25 was significantly correlated with the status of lymph node metastasis and TNM (Tumor, Node and Metastasis) stage. Furthermore, over-expression of miR-25 markedly promoted migration and invasion of ESCC cells. On the contrary, down-regulation of miR-25 inhibited the migration and invasion of cells. E-cadherin(CDH1) is a very important tumor metastasis suppressor. We further identified that miR-25 directly targeted CDH1 3'-untranslated region (3'UTR) and repressed the expression of CDH1. These results, for the first time, demonstrate that miR-25 promotes ESCC cell migration and invasion by suppressing CDH1 expression. 相似文献
952.
953.
Shingo Suzuki Qiu Hongli Aya Okada Takeshi Kasama Ken-ichi Ohta Katsuhiko Warita Kohichi Tanaka Takanori Miki Yoshiki Takeuchi 《Cellular and molecular neurobiology》2012,32(8):1367-1373
Although it is known that brain-derived neurotrophic factor (BDNF) plays a critical role in neuronal survival and differentiation, its effect on lipid homeostasis is poorly understood. To understand them, we here investigated the effect of BDNF on the fatty acid composition of primary neurons. A detailed analysis of the fatty acid composition of BDNF-stimulated primary neurons revealed that BDNF treatment led to a significant and selective increase in intracellular palmitoleic acid (PLO) levels. Correspondingly, BDNF induced the expression of the enzyme responsible for PLO synthesis [stearoyl-CoA desaturase-1]. In addition, this increase was suppressed by K252a, an inhibitor for tropomyosin-related kinase (Trk) receptors, indicating that BDNF-dependent increase in the PLO was mediated through the activation of TrkB. Further, PLO in culture media was reduced by BDNF treatment. This result suggested that BDNF suppressed extracellular release of PLO. Taken together, these data indicate that BDNF increases intracellular PLO both by activating its biosynthesis and by suppressing its extracellular release. 相似文献
954.
The persistent bloom of the brown tide alga Aureoumbra lagunensis has been reported in coastal embayments along southern Texas, but the molecular mechanisms that sustain such algal bloom are unknown. We compared the proteome and physiological parameters of A. lagunensis grown in phosphate (P)-depleted, P- and nitrogen (N)-depleted, and nutrient-replete cultures. For the proteomic analysis, samples from three conditions were subjected to two-dimensional electrophoresis and tandem mass spectrometry analysis. Because of the paucity of genomic resources in this species, a de novo cross-species protein search was used to identify the differentially expressed proteins, which revealed their involvement in several key biological processes, such as chlorophyll synthesis, antioxidative protection, and protein degradation, suggesting that A. lagunensis may adopt intracellular nutrient compensation, extracellular organic nutrient regeneration, and damage protection to thrive in P-depleted environments. A highly abundant P limitation-specific protein, tentatively identified as a putative alkaline phosphatase, was further characterized by enzyme activity assay on nondenaturing gel and confocal microscopy, which confirmed that this protein has alkaline phosphatase activity, is a cytoplasmic protein, and is closely associated with the cell membrane. The abundance, location, and functional expression of this alkaline phosphatase all indicate the importance of organic P utilization for A. lagunensis under P limitation and the possible role of this alkaline phosphatase in regenerating phosphate from extra- or intracellular organic phosphorus. 相似文献
955.
Yufei Wang Yuehua Ke Zhoujia Wang Xitong Yuan Yefeng Qiu Qing Zhen Jie Xu Tiefeng Li Dali Wang Liuyu Huang Zeliang Chen 《Journal of bacteriology》2012,194(21):6012-6013
Live attenuated vaccines play essential roles in the prevention of brucellosis. Here, we report the draft genome sequences of three vaccine strains, Brucella melitensis M5-10, B. suis S2-30, and B. abortus 104M. Primary genome sequence analysis identified mutations, deletions, and insertions which have implications for attenuation and signatures for differential diagnosis. 相似文献
956.
Knowledge of the anti-drug antibody (ADA) status is necessary in early research studies. Because specific assay materials are sparse and time is pressing, a generic assay format with drug tolerance for detection of ADAs in serum samples from mice exposed to immunoglobulin G (IgG) or antigen-binding fragments (Fabs) is highly desirable. This article describes a generic immune complex assay in the sandwich enzyme-linked immunosorbent assay (ELISA) format based on (i) transformation of free ADAs to immune complexes by preincubation with excess drug, (ii) the use of a murine anti-human Fab constant domain Fab as capture reagent, (iii) detection of the immune complexes by a peroxidase-labeled rabbit anti-murine Fc antibody, and (iv) ADA-positive control conjugates consisting of human Fab and murine IgG. Results of the experiments suggest that the generic immune complex assay for mouse serum samples was at least equivalent to specific ADA immune assays and even superior regarding drug tolerance. The generic immune complex assay confers versatility as it detects ADAs in complex with full-length IgG as well as with Fabs independent of the target specificity in mouse serum samples. These features help to save the sparse amounts of specific antibodies available in early research and development and speed up drug candidate selection. 相似文献
957.
Effects of electron donors on anaerobic microbial debromination of polybrominated diphenyl ethers (PBDEs) 总被引:1,自引:0,他引:1
Polybrominated diphenyl ethers (PBDEs) are a class of widely used flame retardants that have been highly accumulated in sediments.
It is reported that microorganisms play an important role in the reductive debromination of PBDEs in anaerobic sediments.
However, little is known about the effects of electron donors on the microbial community structure and their debromination
capacity in PBDE transformation. In this study, alternate carbon substrates were used as electron donors to enrich the PBDE-debrominating
microbial consortia to evaluate the effects of electron donors on PBDE microbial debromination. Decabromodiphenyl ether (BDE-209)
was found to be the dominant (more than 50%) PBDEs congener in all consortia, and the percentage of BDE-209 was deceased by
12% (methanol), 11% (ethanol), 8% (acetate), 9% (lactate), 5% (pyruvate), and 11% (no electron donors), while the relative
abundances of most lesser-brominated PBDEs increased after 90-day incubation compared to the initial profile of PBDEs. Substantial
shifts in the microbial community structure among different amendments were observed based on denaturing gradient gel electrophoresis
results. Pseudomonas spp. were identified to be the predominant organisms and the abundances of Band R, which was associated with Pseudomonas sp. SCSWA09, was well correlated with the biodegradation rate of BDE-209. Finally, the microbial community structure was
highly correlated with the concentration of deca-BDE, octa-BDE and total nitrogen. These results provide insights into in
situ bioremediation of environments contaminated by PBDEs and our understanding of microbial ecology associated with PBDE-debromination. 相似文献
958.
Enzymatic hydrolytic degradation of polybutylene succinate (PBS), poly(polybutylenesuccinate-co-1,4-cyclohexane dimethanol)
(PBS/CHDM) and poly(polybutylene succinate-co-diglycolic acid) (PBS/DGA) in mixed solvent of tetrahydrofuran (THF) and toluene
was examined. Lipase was used as catalyst to degrade polymers with molecular weight of more than 100,000, and the molecular
weight of products ranged from hundreds to thousands. Thermal decomposition temperatures of all products were below 250°C.
The degradation products of both PBS/CHDM and PBS/DGA showed two melting points at about 85 and 99°C. Mass spectrometry (MS)
was employed to obtain the molecular weight of oligomers extracted from the products, which proved to be low-polyesters with
the molecular weight of less 1,000. The butanediol (BDO) monomer was found in PBS/CHDM degradation product for the first time. 相似文献
959.
Comparative studies on the photosynthetic responses of three freshwater phytoplankton species to temperature and light regimes 总被引:2,自引:0,他引:2
The photosynthetic responses of Microcystis aeruginosa, Scenedesmus obliquus, and Cyclotella meneghiniana to temperature and light regimes were investigated. M. aeruginosa had a higher specific growth rate at 30°C than at 14 and 20°C. Its specific growth rate was the maximum among the three species at 30°C. This suggests that M. aeruginosa could predominate in a water body having high temperature. When exposed to high light, M. aeruginosa showed lower maximal photosystem II (PSII) quantum yield (ΦM), operational PSII quantum yield ( $ \Phi_{\text{M}}^{\prime } $ ), and active reaction centers per excited cross section (RC/CSm) than S. obliquus and C. meneghiniana. Moreover, after 2?h low light recovery at 14°C and 20°C, the recovery of ΦM, $ \Phi_{\text{M}}^{\prime } $ and RC/CSm in M. aeruginosa were less than the other two species. This indicates that the capacity of high light adaptation of M. aeruginosa is the lowest among the studied species at 14–20°C. When exposed to high light, C. meneghiniana had higher ΦM and $ \Phi_{\text{M}}^{\prime } $ lost and induced higher nonphotochemical quenching at 14–20°C. This suggests that C. meneghiniana developed a higher resistance to high light under low growth temperatures. M. aeruginosa showed the lowest light compensation point among these three species, which indicates that it could utilize low light more efficiently than the other two species. Cyclic electron flow around PSII may play a role in the photoprotective mechanism of all these three species. 相似文献
960.
Jia Q Jiang X Yu F Qiu J Kang X Cai L Li L Shi W Liu S Jiang S Liu K 《Bioorganic & medicinal chemistry letters》2012,22(7):2393-2395
Serpin A1 (α1-AT), the largest subgroup of serpins, presents in human plasma at high concentration and plays important regulatory roles in physiological and pathological processes. Accumulated evidence suggests that α1-AT may play a role in controlling HIV-1 infection. In this study, we designed and synthesized a set of short linear peptides derived from the C-terminal sequence of α1-AT. Since none of them showed significant anti-HIV-1 activity, we proceeded to synthesize four short cyclic peptides having 7 amino acids, and we found that three of them exhibited significant anti-HIV-1 activity. One of these cyclic peptides, designated CPM, inhibited HIV-1 entry and infection at low μM level, indicating that these short cyclic peptides could serve as leads for the development of novel anti-HIV-1 therapeutics. 相似文献