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51.
Reactive oxygen species have various effects on the expression of cell adhesion molecules induced by pro-inflammatory cytokines, such as tumor necrosis factor &#102 (TNF- &#102 ). We studied the effects of monochloramine (NH 2 Cl), a physiological oxidant derived from activated neutrophils, on the TNF- &#102 -induced expression of e-selectin and intercellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells (HUVEC). HUVEC were pretreated with or without NH 2 Cl (20-90 &#119 M for 20 min), then stimulated with TNF- &#102 (10 ng/ml), and the expression of e-selectin and ICAM-1 was measured. Without NH 2 Cl, TNF- &#102 induced marked expression of e-selectin and ICAM-1. Pretreatment with NH 2 Cl resulted in a significant, but transient inhibition of the expression of adhesion molecules. Higher dose of NH 2 Cl showed more pronounced inhibition, and the inhibitory effect lasted for 8 h when 70 &#119 M of NH 2 Cl was added. TNF- &#102 stimulation also induced marked activation of nuclear factor &#115 B (NF- &#115 B). Notably, NH 2 Cl also inhibited this NF- &#115 B activation in a dose- and time-dependent manner, which was similar to the inhibition of e-selectin and ICAM-1 expression. In addition, I &#115 B- &#102 phosphorylation and degradation were also inhibited by NH 2 Cl pretreatment. These observations indicated that NH 2 Cl inhibited TNF- &#102 -induced expression of e-selectin and ICAM-1 through the inhibition of NF- &#115 B activation. We speculate that neutrophil-derived chloramines may have a regulatory role in the recruitment of leukocytes.  相似文献   
52.
Sustained JNK activation plays a critical role in hepatotoxicity by acetaminophen or GalN/TNF-α. To address the importance of JNK translocation to mitochondria that accompanies sustained activation in these models, we assessed the importance of the expression of a potential initial target of JNK in the outer membrane of mitochondria, namely Sab (SH3 domain-binding protein that preferentially associates with Btk), also known as Sh3bp5 (SH3 domain-binding protein 5). Silencing the expression of Sab in the liver using adenoviral shRNA inhibited sustained JNK activation and mitochondrial targeting of JNK and the upstream MKK4 (MAPK kinase 4), accompanied by striking protection against liver injury in vivo and in cultured hepatocytes in both toxicity models. We conclude that mitochondrial Sab may serve as a platform for the MAPK pathway enzymes and that the interaction of stress-activated JNK with Sab is required for sustained JNK activation and toxicity.  相似文献   
53.
Death receptors belong to the tumor necrosis factor receptor (TNFR) super family and are intimately involved in the signal transduction during apoptosis, stress response and cellular survival. Here we present the crystal structure of recombinantly expressed death receptor six (DR6), one family member that was recently shown to bind to the amyloid precursor protein (APP) and hence to be probably involved in the development of Alzheimer's disease. The extracellular cysteine rich region of DR6, the typical ligand binding region of all TNFRs, was refined to 2.2 Å resolution and shows that its four constituting cysteine rich domains (CRDs) are arranged in a rod-like overall structure, which presents DR6-specific surface patches responsible for the exclusive recognition of its ligand(s). Based on the structural data, the general ligand binding modes of TNFRs and molecular modeling experiments we were able to elucidate structural features of the potential DR6-APP signaling complex.  相似文献   
54.
Pigtailed macaques (Macaca nemestrina) provide an important model for biomedical research on human disease and for studying the evolution of primate behavior. The genetic structure of captive populations of pigtailed macaques is not as well described as that of captive rhesus (M. mulatta) or cynomolgus (M. fascicularis) macaques. The Washington National Primate Research Center houses the largest captive colony of pigtailed macaques located in several different housing facilities. Based on genotypes of 18 microsatellite (short tandem repeat [STR]) loci, these pigtailed macaques are more genetically diverse than captive rhesus macaques and exhibit relatively low levels of inbreeding. Colony genetic management facilitates the maintenance of genetic variability without compromising production goals of a breeding facility. The periodic introduction of new founders from specific sources to separate housing facilities at different times influenced the colony's genetic structure over time and space markedly but did not alter its genetic diversity significantly. Changes in genetic structure over time were predominantly due to the inclusion of animals from the Yerkes National Primate Research Center in the original colony and after 2005. Strategies to equalize founder representation in the colony have maximized the representation of the founders’ genomes in the extant population. Were exchange of animals among the facilities increased, further differentiation could be avoided. The use of highly differentiated animals may confound interpretations of phenotypic differences due to the inflation of the genetic contribution to phenotypic variance of heritable traits. Am. J. Primatol. 74:1017‐1027, 2012. © 2012 Wiley Periodicals, Inc.  相似文献   
55.
目的:尝试应用RNA干扰(RNAi)沉默猪源PK-15细胞中的猪内源性反转录病毒(PERV),并通过反转录酶活性及pol基因相对荧光定量PCR检测沉默效果。方法:依据GenBank公布的PERV pol基因序列,采用Invitro-gen公司的BLOCK-iT RNAi Designer软件设计Stealth小干扰RNA(siRNA)序列;将合成的siRNA转染PK-15细胞,72 h后检测细胞上清PERV反转录酶活性及细胞内pol基因拷贝数并评价沉默效果。结果:反转录酶活性及pol基因拷贝数检测结果表明,设计的3条Stealth siRNA序列中,位于pol基因3272~3296 bp的序列能有效沉默PERV。结论:RNAi方法可有效使猪源PK-15细胞中的PERV沉默,为进一步研究天然抗病毒分子与PERV的相互作用提供了实验基础,同时也为猪源异种移植研究中去除PERV提供了一种可供尝试的方法。  相似文献   
56.
江涛  赵俊玲  程建军  徐帅  苏文  包善微  刘芳 《昆虫知识》2011,48(5):1359-1368
于2010年在田间条件下研究了水稻品种和氮肥施用水平(250 kg/hm2有效氮,125 kg/hm2有效氮及不施氮肥的处理)对褐飞虱Nilaparvata tugens(St(a)l)发生的影响.结果表明,8月10日-9月10日期间,南粳44、宁粳1号、丙123、淮稻9号4个水稻品种上褐飞虱虫量显著低于感虫对照TN1...  相似文献   
57.
目的:探索硫氧还蛋白(Trx)抗体柱对Trx融合蛋白纯化的可行性。方法与结果:对含有Trx基因的质粒表达载体pTrxFus进行改造,在Trx读框之后加入6×His序列,并在大肠杆菌中表达C端带有6×His标签的Trx,经Ni2+柱亲和纯化后制备多克隆抗体;把经蛋白A纯化后的抗体偶联在溴化氰活化的琼脂糖凝胶上,制成Trx抗体柱;用此抗体柱纯化与Trx融合表达的豇豆胰蛋白酶抑制剂(CpTI),SDS-PAGE结果显示获得了纯度较高的Trx-CpTI。结论:用Trx抗体制成的免疫亲和层析柱可以有效纯化Trx融合蛋白。  相似文献   
58.
鸟苷发酵过程的多尺度问题研究   总被引:4,自引:0,他引:4  
以鸟苷发酵为对象,在生物反应器中以多尺度问题的角度,对在线计算机数据进行相关分析,结合中间代谢物及有关酶活性的检测,建立了以代谢流为核心的多尺度调控方法;又通过与代谢流迁移有关的动态化学计量分析,实现了对批式发酵过程的时变系统估算,建立了主体代谢与产物形成的支路代谢间,包括能量与物质流的关系模型;最后,把具有不同生产能力菌株的关键基因与基因库数据进行了序列比较,发现了本文研究的菌株已具备高产能力,即编码sAMP合成酶的基因发生移码突变以及pur操纵子的多处突变,而中心代谢流迁移是过程优化的关键。对开展微生物功能基因组学的研究和工业过程优化的问题进行了探讨,作者提出有必要从生物反应器的系统生物学高度来认识和解决所面临的问题。  相似文献   
59.
60.
Functional analyses of placental protein 13/galectin-13.   总被引:7,自引:0,他引:7  
Placental protein 13 (PP13) was cloned from human term placenta. As sequence analyses, alignments and computational modelling showed its conserved structural and functional homology to members of the galectin family, the protein was designated galectin-13. Similar to human eosinophil Charcot-Leyden crystal protein/galectin-10 but not other galectins, its weak lysophospholipase activity was confirmed by 31P-NMR. In this study, recombinant PP13/galectin-13 was expressed and specific monoclonal antibody to PP13 was developed. Endogenous lysophospholipase activity of both the purified and also the recombinant protein was verified. Sugar binding assays revealed that N-acetyl-lactosamine, mannose and N-acetyl-glucosamine residues widely expressed in human placenta had the strongest binding affinity to both the purified and recombinant PP13/galectin-13, which also effectively agglutinated erythrocytes. The protein was found to be a homodimer of 16 kDa subunits linked together by disulphide bonds, a phenomenon differing from the noncovalent dimerization of previously known prototype galectins. Furthermore, reducing agents were shown to decrease its sugar binding activity and abolish its haemagglutination. Phosphorylation sites were computed on PP13/galectin-13, and phosphorylation of the purified protein was confirmed. Using affinity chromatography, PAGE, MALDI-TOF MS and post source decay, annexin II and beta/gamma actin were identified as proteins specifically bound to PP13/galectin-13 in placenta and fetal hepatic cells. Perinuclear staining of the syncytiotrophoblasts showed its expression in these cells, while strong labelling of the syncytiotrophoblasts' brush border membrane confirmed its galectin-like externalization to the cell surface. Knowing its colocalization and specific binding to annexin II, PP13/galectin-13 was assumed to be secreted to the outer cell surface by ectocytosis, in microvesicles containing actin and annexin II. With regard to our functional and immunomorphological results, PP13/galectin-13 may have special haemostatic and immunobiological functions at the lining of the common feto-maternal blood-spaces or developmental role in the placenta.  相似文献   
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