表没食子儿茶素没食子酸酯对高糖培养的系膜细胞糖原合成酶激酶-3β和细胞外基质合成的影响

目的观察高糖对大鼠肾小球系膜细胞（GMCs）糖原合成酶激酶-3β（GSK-3β）及细胞外基质成分（ECM）的影响及表没食子儿茶素没食子酸酯（EGCG）的干预效果。方法以大鼠GMCs为实验对象,培养48h后,用四甲基偶氮唑蓝（MTT）测定GMCs增殖情况,Western blot法测定GSK-3β蛋白表达,酶联免疫吸附实验（ELISA）检测高糖条件下细胞培养液中细胞外基质成分纤维连接蛋白（FN）、Ⅳ型胶原（ColⅣ）及层粘连蛋白（LN）的含量。结果高糖明显诱导GMCs增殖并抑制GSK-3β磷酸化,EGCG和GSK-3β特异性的抑制剂TDZD-8均能抑制高糖诱导的细胞增生,并增加GSK-3β磷酸化水平。高糖环境下系膜细胞分泌的FN、ColⅣ及LN明显增加（P〈0.05）,EGCG能抑制上述作用。结论EGCG通过GSK-3β信号通路抑制高糖诱导的GMCs增殖,并能抑制GMCs细胞外基质的合成,从而延缓糖尿病肾小球肥大和肾小球硬化。     

柴苓小方对大鼠肾小球系膜细胞异常增殖的影响

目的：探讨柴苓小方对大鼠肾小球系膜细胞（GMCs）异常增殖的影响及相关机制。方法：采用脂多糖刺激系膜细胞异常增殖。MTT法检测柴苓小方对㈣异常增殖的影响；免疫细胞化学方法检测药物作用后增殖细胞核抗原（PCNA）的表达；乳酸脱氢酶释放实验检测柴苓小方的细胞毒作用。采用RT—PCR检测药物作用不同时间点细胞周期蛋白依赖性激酶抑制剂p21的表达。结果：柴苓小方可以剂量依赖性的抑制系膜细胞异常增殖并显著减少PCNA阳性细胞数而没有明显的细胞毒作用。并且柴苓小方可以显著地上调p21基因的表达（P〈0．05）。结论：柴苓小方可剂量依赖性的抑制GMC8异常增殖．其机制可能与上调p21mRNA表达有关。     

Characterization of size, structure and purity of serogroup X Neisseria meningitidis polysaccharide, and development of an assay for quantification of human antibodies

Serogroup X Neisseria meningitidis (MenX) has recently emerged as a cause of localized disease outbreaks in sub-Saharan Africa. In order to prepare for vaccine development, MenX polysaccharide (MenX PS) was purified by standard methods and analyzed for identity and structure by NMR spectroscopy. This study presents the first full assignment of the structure of the MenX PS using (13)C, (1)H and (31)P NMR spectroscopy and total correlation spectroscopy (TOCSY) and (1)H-(13)C heteronuclear single quantum coherence (HSQC). Molecular size distribution analysis using HPLC-SEC with multi-angle laser light scattering (MALLS) found the single peak of MenX PS to have a weight-average molar mass of 247,000g/mol, slightly higher than a reference preparation of purified serogroup C meningococcal polysaccharide. MenX PS tended to be more thermostable than serogroup A PS. A method for the quantification of MenX PS was developed by use of high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). A novel and specific ELISA assay for quantification of human anti-MenX PS IgG based on covalent linkage of the MenX PS to functionally modified microtitre plates was developed and found valid for the assessment of the specific antibody concentrations produced in response to MenX vaccination or natural infection. The current work thus provides the necessary background for the development of a MenX PS-based vaccine to prevent meningococcal infection caused by bacteria bearing this capsule.     

Curcumin ameliorates diabetic nephropathy by inhibiting the activation of the SphK1-S1P signaling pathway

Curcumin, a major polyphenol from the golden spice Curcuma longa commonly known as turmeric, has been recently discovered to have renoprotective effects on diabetic nephropathy (DN). However, the mechanisms underlying these effects remain unclear. We previously demonstrated that the sphingosine kinase 1-sphingosine 1-phosphate (SphK1-S1P) signaling pathway plays a pivotal role in the pathogenesis of DN. This study aims to investigate whether the renoprotective effects of curcumin on DN are associated with its inhibitory effects on the SphK1-S1P signaling pathway. Our results demonstrated that the expression and activity of SphK1 and the production of S1P were significantly down-regulated by curcumin in diabetic rat kidneys and glomerular mesangial cells (GMCs) exposed to high glucose (HG). Simultaneously, SphK1-S1P-mediated fibronectin (FN) and transforming growth factor-beta 1 (TGF-β1) overproduction were inhibited. In addition, curcumin dose dependently reduced SphK1 expression and activity in GMCs transfected with SphK^WT and significantly suppressed the increase in SphK1-mediated FN levels. Furthermore, curcumin inhibited the DNA-binding activity of activator protein 1 (AP-1), and c-Jun small interference RNA (c-Jun-siRNA) reversed the HG-induced up-regulation of SphK1. These findings suggested that down-regulation of the SphK1-S1P pathway is probably a novel mechanism by which curcumin improves the progression of DN. Inhibiting AP-1 activation is one of the therapeutic targets of curcumin to modulate the SphK1-S1P signaling pathway, thereby preventing diabetic renal fibrosis.     

ＰＩ３-Ｋ／Ａｋｔ ｓｈＲＮＡ真核表达质粒的构建及鉴定

目的:构建针对P13-K/Akt基因的特异性短发卡RNA(shRNA)真核表达载体.方法:用DNA重组技术将针对大P13-K/Akt基因不同位点所设计的8个shRNA序列克隆到真核表达质粒pGenesil-1中.在酶切分析及序列测定后,用脂质体染至大鼠肾小球系膜细胞(GMCs).Western blot检测蛋白的相对表达量来筛选最佳沉默效率的shRNA.结果:限制性酶切及酸序列分析证明重组质粒正确.Western blot证实在重组质粒中shPik3c3-2、shAktl-4具有最佳沉默效率.结论:成功构建了PK/Akt shRNA的真核表达质粒.该实验结果为进一步研究P13-K/Akt信号通路的生物学功能奠定了基础.     

基因芯片筛查亚溶解型C5b-9刺激大鼠肾小球系膜细胞基因表达差异的研究

目的:应用高通量的基因芯片技术筛查亚溶解型C5b-9(sublytic C5b-9)介导大鼠肾小球系膜细胞(glomerular mesangial cells, GMCs)的基因表达谱的变化?方法:体外分离?培养大鼠GMCs,人工质控sublytic C5b-9复合物的形成,并用其刺激培养GMCs,然后分别提取sublytic C5b-9刺激GMCs 40 min?3 h及未刺激对照组细胞的总RNA?经逆转录合成生物素标记的cDNA探针,然后与基因芯片杂交(涵盖31 000个转录本,代表28 000个基因)?经Affymetrix Scanner 3000 扫描芯片荧光信号图像?GCOS1.4读取数据后将差异表达基因注释于GO基因功能分类体系,分析其相应的功能?结果:芯片检查数据显示,sublytic C5b-9刺激GMCs 40 min 时上调2倍以上及下调2倍以上的基因分别为4 124个和2 234个,刺激3 h时上调2倍以上及下调2倍以上的基因分别为4 512个和2 859个;而sublytic C5b-9刺激GMCs 40 min和3 h后同时上调2倍以上及下调2倍以上的基因分别为2 325个和1 419个?sublytic C5b-9刺激GMCs表达差异基因其功能主要涉及生物学过程调节?生物调节?定位相关?刺激应答?生长发育?增殖?代谢过程?细胞生理过程?多细胞机体过程等?结论:Sublytic C5b-9 刺激GMCs确能引起基因表达谱的变化?     

TSP-1 promotes glomerular mesangial cell proliferation and extracellular matrix secretion in Thy-1 nephritis rats

The proliferation of glomerular mesangial cells (GMC) and secretion of the extracellular matrix (ECM) in rat with Thy-1 nephritis (Thy-1N) resembling human mesangioproliferative glomerulonephritis have been explored for many years; however, the molecular mechanisms of GMC proliferation and ECM production remain unclear. Our previous studies have demonstrated that the thrombospondin-1 (TSP-1) gene was involved in mediating rat GMC proliferation and ECM synthesis induced by sublytic C5b-9 in vitro. In the pre...     

LEF 对肾小球系膜细胞增殖及分泌细胞外基质的影响

目的: 探讨来氟米特对转化生长因子－β1刺激的大鼠肾小球系膜细胞( GMCs) 增殖及细胞外基质
( ECM) 分泌的影响。方法: 体外培养大鼠肾小球系膜细胞,分正常对照组,TGF－β1( 5 ng /mL) 刺激组,TGF－β1 +
LEF( LEF 浓度分别为5μmol /L、25μmol /L、50μmol /L、100μmol /L) 组,培养24h、48h 和72h 后,MTT 法观察各组
肾小球系膜细胞在不同时间点的增殖情况; ELISA 法测定各组培养细胞上清液中纤连蛋白的含量。结果: ( 1) 与
对照组相比,TGF－β1可刺激系膜细胞增殖,不同浓度的LEF 均可以抑制TGF－β1刺激的系膜细胞增殖( P＜0．05) ,48h 后抑制作
用稳定。( 2) TGF－β1刺激组细胞上清液中纤连蛋白含量明显高于对照组( P＜0．05) ,不同浓度的LEF 组纤连蛋白含量明显低于TGF－β1
组( P＜0．05) 。结论: 来氟米特可以抑制TGF－β1刺激的肾小球系膜细胞的增殖,减少细胞外基质的分泌,为其治疗慢性肾脏病提供理论依据。     

Sublytic complement C5b-9 complexes induce thrombospondin-1 production in rat glomerular mesangial cells via PI3-k/Akt: association with activation of latent transforming growth factor-beta1

Mesangial cell proliferation is a common cellular response to a variety of different types of glomerular injury. Complement C5b-9 is a prime candidate to mediate mesangial cell proliferation, especially sublytic C5b-9, which can induce the production of multiple inflammatory factors and cytokines. Transforming growth factor (TGF)-beta1 plays a major role in the accumulation of extracellular matrix (ECM), while thrombospondin (TSP)-1 has been identified as an activator of latent TGF-beta1 in an in vitro system. Using rat glomerular mesangial cells (GMCs) as a model system, we assessed the effect of sublytic C5b-9 on the expression of TSP-1 and TGF-beta1 and explored the relevant pathway of signal transduction. First, we ensured the concentrations of anti-Thy1 antibody and complement, which were regarded as a sublytic C5b-9 dose, and examined whether the sublytic C5b-9 induced expression of TSP-1 in rat GMCs which, in turn, activated latent TGF-beta1 by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Then, we investigated the role of the PI3-k/Akt pathway in sublytic C5b-9-induced TSP-1 production in rat GMCs by Western blot analysis. The addition of sublytic C5b-9 (5% anti-Thy1 antibody and 4% normal serum) to rat GMCs induced activation of latent TGF-beta1 via TSP-1. The addition of sublytic C5b-9 apparently increased the protein of Akt phosphorylation, whereas PI3-k inhibitor LY294002 could clearly reduce the increase of TSP-1 induced by sublytic C5b-9. These results indicate that TSP-1 is an activator of latent TGF-beta1 in sublytic C5b-9-induced rat GMCs; furthermore, the PI3-k/Akt signal transduction pathway may play a key role in sublytic C5b-9-induced TSP-1 production.