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991.
Luo M Qiu J Zhang Y Wang J Dong J Li H Leng B Zhang Q Dai X Niu X Zhao S Deng X 《Journal of microbiology and biotechnology》2012,22(8):1170-1176
In this study, we aimed to evaluate the effect of α- cyperone on S. aureus. We used a hemolysin test to examine the hemolytic activity in supernatants of S. aureus cultured with increasing concentrations of α- cyperone. In addition, we evaluated the production of α- hemolysin (Hla) by Western blotting. Real-time RT-PCR was performed to test the expression of hla (the gene encoding Hla) and agr (accessory gene regulator). Furthermore, we investigated the protective effect of α- cyperone on Hla-induced injury of A549 lung cells by live/ dead and cytotoxicity assays. We showed that in the presence of subinhibitory concentrations of α-cyperone, Hla production was markedly inhibited. Moreover, α- cyperone protected lung cells from Hla-induced injury. These findings indicate that α-cyperone is a promising inhibitor of Hla production by S. aureus and protects lung cells from this bacterium. Thus, α-cyperone may provide the basis for a new strategy to combat S. aureus pneumonia. 相似文献
992.
The macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays an important role in the pathogenesis of immune diseases. High levels of MIF have been detected in the sera of patients with tuberculosis (TB), and it has been proposed that MIF gene polymorphisms may influence the risk of developing TB. The aim of this study was to evaluate the potential relationship between functional polymorphisms of MIF and TB in a Han population from Southwestern China. TB patients (n=215) and healthy unrelated controls (n=245) were recruited for this study. Genomic DNA was isolated from all the participants. The MIF-173 G/C SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The MIF-794 CATT(5-8) microsatellite was evaluated by direct sequencing of the subsequent PCR products. Association analysis of the two polymorphisms showed that the frequency of -173 (GC+CC) in TB patients and controls was 49.3% and 31.4%, respectively, which was statistically significant (OR=2.12, 95% CI=1.45-3.10, P<0.001); the frequencies of -794 (7/X+8/X) were 56.7% and 45.3%, respectively, also statistically significant between the TB and healthy controls (OR=1.58, 95% CI=1.10-2.29, P=0.015). In summary, Genetic variation in the MIF gene is closely associated with tuberculosis. Both the 173 (GC+CC) SNP and -794 (7/X+8/X) microsatellite increased the risk of Chinese Han developing TB. 相似文献
993.
The preprotein translocase of the inner mitochondrial membrane (TIM23 complex) is the main entry gate for proteins of the matrix and the inner membrane. Tim23 forms a pore for preprotein transportation in TIM23 complex, which spans the inner membrane with transmembrane segments and exposes a hydrophilic domain in the intermembrane space. In this study, we expressed and purified the intermembrane space (IMS) domain of human Tim23 (Tim23(IMS)). The far-UV CD spectra of Tim23(IMS) in native and denatured states revealed that the protein has a limited secondary structure and a not well-defined tertiary packing. Its Stokes radius was larger than both its expected size as a folded globular protein and the size determined by size exclusion chromatography. A large increase in 8-anilino-1-naphthalene-sulfonate (ANS) fluorescence (>50-fold) was observed, indicating that hydrophobic clusters are exposed at its surface. And GlobPlot/DisEMBL program predicted that the protein is in a loose folding state. We therefore conclude that, the non-bound hydrophilic domain of the human Tim23 is in a molten globule configuration with marginal stability. Furthermore, size exclusion chromatography and sedimentation equilibrium analysis showed that Tim23(IMS) exists as a dimer. And the results, showed by ANS binding and fluorescence quenching, indicated that a pH-dependent conformational change of Tim23(IMS) occurs, and at pH 4 and 3, it forms a compact structure. 相似文献
994.
Zheng Z Yingeng W Qingyin W Nannan D Meijie L Jiangbo Q Bin L Lan W 《Fish & shellfish immunology》2012,32(3):391-395
In this study, we investigated the immune enhancing effects of different adjuvants used in a pentavalent vaccine for turbots. The pentavalent vaccine consisted of inactive bacterial cells from five common pathogenic strains (Vibrio anguillarum, Vibrio scophtalmi, Edwardsiella tarda, Vibrio harveyi and Vibrio alginolyticus) and the adjuvants were astragalus polysaccharides (APS), propolis, and the Freund’s complete adjuvant (FCA). Turbots were immunized with the pentavalent vaccine alone or with one of the adjuvants, and the immune efficiency was evaluated by measuring the activities of lysozyme (LSZ) and superoxide dismutase (SOD), and serum antibody titers. Fish were also challenged with the pathogens after immunization and the relative percent survival (RPS) was assessed. Our results showed that APS, propolis, and FCA had significant immune-enhancing effects on turbots as shown by the higher titers of antibodies against the pathogens, increased LSZ and SOD activities, and enhanced RPS after challenge with pathogens. Among the three adjuvants, FCA had the most significant immune synergistic effects with the vaccine, and APS and propolis had lower and similar immune synergies. 相似文献
995.
T lymphocyte activation requires a combination of signals, one of which is provided by interaction between CD28 and its ligands on antigen presenting cells. Although CD28-like sequences have been identified in a few teleosts, the function of fish CD28 is virtually unknown. In this study, we cloned and analyzed a CD28 gene, CsCD28, from half-smooth tongue sole (Cynoglossus semilaevis). The deduced amino acid sequence of CsCD28 contains 229 residues and shares 20.2%-40.3% overall sequence identities with known fish CD28 sequences. CsCD28 possesses structural features conserved in mammalian and teleost CD28, which include the MYPPPY motif in the extracellular immunoglobulin-like domain and the YXN motif in the cytoplasmic domain. The CsCD28 gene is 2746 bp and composed of four exons and three introns, which in organization resemble those of mammalian and trout CD28. Quantitative real time RT-PCR analysis showed that CsCD28 expression occurred predominately in kidney, spleen, gut, and gill. CsCD28 is localized on the surface of head kidney lymphocytes, and antibody ligation of CsCD28 induced significant levels of cellular proliferation. Taken together, these results indicate that CsCD28 is similar to mammalian CD28 in genetic and protein structures and possibly plays a role in T cell activation. 相似文献
996.
Guo C He Z Wen L Zhu L Lu Y Deng S Yang Y Wei Q Yuan H 《Cell biology international》2012,36(2):183-188
An outbreak of urinary stones associated with consumption of melamine-tainted milk products occurred in 2008 in China, leading to serious illness of many infants and even death. However, the toxicity of melamine in kidney epithelial cells remains unclear. We have explored the effects of melamine and trolox on renal NRK-52e (normal rat kidney 52e) cells. The IC(50) of melamine was measured by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay. Total SOD (superoxide dismutase) was determined by NBT (Nitro Blue Tetrazolium) staining method. GSH-Px (glutathione peroxidase) activity was detected by UV colorimetric assay, and MDA (malondialdehyde) content was determined by thiobarbituric acid assay. Apoptosis induced by melamine was determined by flow cytometry. The IC(50) increased when NRK-52e cells were treated with both melamine and trolox compared with melamine only. SOD and GSH-Px activities were decreased, but MDA content was increased by melamine in a dose-dependent manner. Trolox significantly enhanced SOD and GSH-Px activity in melamine-treated NRK-52e cells, but it decreased their MDA content. LDH (lactate dehydrogenase) activity and the level of ROS (reactive oxygen species) of the NRK-52e cells were enhanced by melamine compared with the control. Furthermore, the apoptosis rate increased in NRK-52e cells treated with melamine, whereas trolox was protective. These results show that melamine has an obvious adverse effect on proliferation of NRK-52e cells, causing oxidative damage and apoptosis, thus providing a novel insight into renal cytotoxicology of melamine. Trolox ameliorates the effect on melamine toxicity. 相似文献
997.
998.
Lin L Pan G Li T Dang X Deng Y Ma C Chen J Luo J Zhou Z 《The Journal of eukaryotic microbiology》2012,59(3):251-257
Microsporidia, an unusual group of unicellular parasites related to fungi, possess a highly reduced mitochondrion known as the mitosome. Since mitosomes lack an organellar genome, their proteins must be translated in the cytosol before being imported into the mitosome via translocases. We have identified a Tom40 gene (NbTom40), the main component of the translocase of the outer mitochondrial membrane, in the genome of the microsporidian Nosema bombycis. NbTom40 is reduced in size, but it is predicted to form a β-barrel structure composed of 19 β-strands. Phylogenetic analysis confirms that NbTom40 forms a clade with Tom40 sequences from other species, distinct from a related clade of voltage-dependent anion channels (VDACs). The NbTom40 contains a β-signal motif that the polar residue is substituted by glycine. Furthermore, we show that expression of NbTom40, as a GFP fusion protein within yeast cells, directs GFP to mitochondria of yeast. These findings suggest that NbTom40 may serve as an import channel of the microsporidian mitosome and facilitate protein translocation into this organelle. 相似文献
999.
Xuemei Zhang Susan Kadlubar Jingsheng Tuo Bridgett Green Helen Deng Baitang Ning 《Journal of biochemical and molecular toxicology》2012,26(10):422-428
Previously, we reported five common single nucleotide polymorphisms (SNPs), ?624G>C, ?396G>A, ?358A>C, ?341C>G, and ?294T>C, and six common haplotypes (CGACT, GAACT, GGAGC, GGACC, CAACT, and GAACC) in the 5′‐flanking region of the SULT1A1 gene that were associated with altered enzymatic activity. In the present study, we performed in vitro assays to determine the functional impact of these genetic variations on the promoter activity. Dual luciferase reporter assays revealed that these SNPs are located in a negative regulatory fragment of the SULT1A1 gene. Further experiments demonstrated that these SNPs and haplotypes affected promoter activities of SULT1A1. Electrophoretic mobility shift assays showed distinctive binding patterns for the SNPs ‐396G>A and ‐294T>C, due to differential binding affinities of the G/A alleles and the T/C alleles to nuclear proteins extracted from the liver carcinoma cell lines, HepG2 and Huh7. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:422–428, 2012; View this article online at wileyonlinelibrary.com . DOI 10:1002/jbt.21437 相似文献
1000.
C Li P Yang Y Zhang Y Sun W Wang Z Zou L Xing Z Chen C Tang F Guo J Deng Y Zhao Y Yan J Tang X Wang C Jiang 《PloS one》2012,7(8):e44110