高糖条件下Tensin在人肾脏系膜细胞上的表达

目的: 探讨在高糖刺激的条件下,Tensin在人类肾脏系膜细胞上的表达及变化.方法: 体外培养系膜细胞,用含不同浓度的葡萄糖(5 mmol/L,30 mmol/L)刺激细胞48 h、 72 h和5 d.用免疫荧光法观察tensin在人类肾脏系膜细胞上表达及变化,ELISA法检测上清液中纤连蛋白含量.结果: 高糖刺激下系膜细胞tensin的表达随着培养时间的延长逐渐增多,且纤连蛋白的分泌也随培养时间的延长而增加.结论: 高糖刺激下tensin在人类肾脏系膜细胞的细胞膜上表达增加,在细胞外基质增多的发生机制中起重要作用.     

ERK促进大鼠胸主动脉血管平滑肌细胞Smad7表达

研究表明,在多种细胞,转化生长因子(transforming growth factor-β,TGF-β)/Smad与细胞外信号调节蛋白激酶(extra cellalar signal regulated protein,ERK)信号传导通路可在多个环节存在相互调节[1].但在血管平滑肌细胞(vascu-lar smooth muscle cells,VSMCs),这两条通路是否存在类似关系,作为抑制性分子Smad7的作用目前还不清楚.本研究观察大鼠胸主动脉VSMCs内ERK通路对Smad7蛋白及其mRNA表达的影响.     

氯沙坦通过ERK1/2 MAPK途径抑制高糖诱导小鼠系膜细胞CTGF表达

目的: 研究高糖环境下, 氯沙坦对CTGF的影响以及其作用机制.方法: 体外培养小鼠系膜细胞株(MMCs), 用高糖(25 mmol/L葡萄糖)刺激细胞分别作用24 h、 48 h、 72 h, 用Western blot方法检测磷酸化ERK1/2的表达.再将细胞分为低糖组(5.6 mmol/L葡萄糖), 山梨醇组(5.6 mmol/L葡萄糖+19.4 mmol/L山梨醇), 高糖组(25 mmol/L葡萄糖), 氯沙坦组(25 mmol/L葡萄糖+10-5 mol/L氯沙坦)以及 ERK抑制剂组(25 mmol/L葡萄糖+ 25 μmol/L PD98059), 48 h后采用Western blot方法检测磷酸化ERK1/2的表达, 72 h后采用Real-time PCR方法及Western blot分别检测 CTGF mRNA表达量以及蛋白的表达.结果: 高糖刺激小鼠系膜细胞后, ERK1/2磷酸化的蛋白表达逐渐增高, 呈现一定时间依赖性.与低糖组相比, 高糖组磷酸化ERK1/2、 CTGF的蛋白表达明显增加(P<0.01), 而与高糖组相比, 氯沙坦组以及ERK抑制剂组磷酸化ERK1/2的蛋白表达以及CTGF的蛋白均明显下降有统计学意义(P<0.05).与低糖组相比, 高糖组CTGF mRNA表达量明显增加(P<0.01), 而与高糖组相比, 氯沙坦组以及ERK抑制剂组CTGF mRNA表达量明显下降, 且有统计学意义(P<0.01).结论: 氯沙坦可抑制高糖对CTGF的诱导作用, 其机制可能与抑制ERK1/2 MAPK途径有关.     

下调Notch1信号抑制人神经母细胞瘤SH-SY5Y的增殖能力

 目的 探讨Notch1基因与人神经母细胞瘤SH-SY5Y细胞增殖能力的关系。方法 应用?-分泌酶抑制剂DAPT或表达Notch1-shRNA慢病毒载体阻断SH-SY5Y细胞Notch1信号的活化,RT-PCR和Western blot法行Notch1及Hes1表达水平的检测,MTT法和裸鼠体内种植检测瘤细胞体内外增殖能力的变化。结果 DAPT处理和表达Notch1-shRNA慢病毒载体转染均能减少细胞内NICD和Hes1表达,其细胞体外增殖能力受到明显抑制(P<0.01),Notch1RNAi细胞体内种植瘤重为0.20±0.13g,明显轻于对照组的0.89±0.58g（P<0.01)。结论 Notch1信号的活化与人神经母细胞瘤SH-SY5Y细胞的增殖能力密切相关,有望成为神经母细胞瘤基因治疗的潜在靶点。     

辛伐他汀对尼古丁诱导脐静脉 内皮细胞分泌t-PA和PAI-1的影响

目的: 研究不同浓度辛伐他汀对尼古丁诱导人脐静脉内皮细胞(HUVECs)分泌组织纤溶酶原激活物(t-PA)和1型纤溶酶原激活物抑制剂(PAI-1)及其基因表达的影响。方法: 将3-6代体外培养的HUVECs随机分为对照组、尼古丁组及不同浓度辛伐他汀组,辛伐他汀组分别以1、10、100 μmol/L辛伐他汀预处理细胞2 h,再以100 μmol/L尼古丁孵育24 h。酶联免疫吸附双抗体夹心法(ELISA)检测细胞上清液t-PA和PAI-1含量;逆转录聚合酶链反应(RT-PCR)检测细胞t-PA和PAI-1 mRNA的表达。结果: 尼古丁组PAI-1分泌和mRNA表达较对照组显著升高(P<0.05)。不同浓度辛伐他汀组PAI-1分泌和mRNA表达均较尼古丁组显著降低,且PAI-1分泌和mRNA表达的降低呈浓度依赖性(均P<0.05),以100 μmol/L辛伐他汀组最为显著。100 μmol/L辛伐他汀组PAI-1分泌和mRNA表达与对照组比较,无显著差异(P>0.05)。尼古丁组t-PA mRNA表达较对照组显著降低(P<0.05)。10、100 μmol/L辛伐他汀组t-PA mRNA表达较尼古丁组显著升高(P<0.05),各组间t-PA分泌无显著差异(均P>0.05)。结论: 在体外,辛伐他汀可降低尼古丁所致的PAI-1分泌和mRNA的表达,并升高t-PA mRNA的表达,从而逆转尼古丁介导的HUVECs纤溶活性减低。     

Localization and expression of the aquaporin-1 water channel in mesangial cells in the human glomerulus

The expression and localization of the aquaporin-1 (AQP1) water channel were examined in the glomeruli of the human kidney. A ribonuclease protection assay showed the expression of AQP1 mRNA in human glomeruli but not in rat glomeruli. Western blot analysis revealed 28 kDa and 35 kDa bands corresponding to unglycosylated and glycosylated AQP1 proteins in human glomeruli. Immunoreactive AQP1 was demonstrated almost exclusively in the mesangium in the human glomeruli by immunohistochemistry. The endothelium of glomerular capillaries was only partly immunostained while podocytes and Bowman's capsule epithelia were not immunolabeled. Immunoelectron microscopy localized the immunoreactive AQP1 on the plasma membrane of mesangial cells in human glomeruli. The immouno-gold labeling was dense on the projections of mesangial cells protruding to the glomerular capillary lumen or to endothelial cells, but was sparse on other parts of the mesangial cell surface. No immunoreactivity for AQP1 was demonstrated in rat glomeruli. This study showed the distinct localization of AQP1 in the mesangial cells of human glomeruli, suggesting its role in water movement through these cells.     

The effects of acellular amniotic membrane matrix on osteogenic differentiation and ERK1/2 signaling in human dental apical papilla cells

The amniotic membrane (AM) has been widely used in the field of tissue engineering because of the favorable biological properties for scaffolding material. However, little is known about the effects of an acellular AM matrix on the osteogenic differentiation of mesenchymal stem cells. In this study, it was found that both basement membrane side and collagenous stroma side of the acellular AM matrix were capable of providing a preferential environment for driving the osteogenic differentiation of human dental apical papilla cells (APCs) with proven stem cell characteristics. Acellular AM matrix potentiated the induction effect of osteogenic supplements (OS) such as ascorbic acid, β-glycerophosphate, and dexamethasone and enhanced the osteogenic differentiation of APCs, as seen by increased core-binding factor alpha 1 (Cbfa-1) phosphorylation, alkaline phosphatase activity, mRNA expression of osteogenic marker genes, and mineralized matrix deposition. Even in the absence of soluble OS, acellular AM matrix also could exert the substrate-induced effect on initiating APCs’ differentiation. Especially, the collagenous stroma side was more effective than the basement membrane side. Moreover, the AM-induced effect was significantly inhibited by U0126, an inhibitor of extracellular signaling-regulated kinase 1/2 (ERK1/2) signaling. Taken together, the osteogenic differentiation promoting effect on APCs is AM-specific, which provides potential applications of acellular AM matrix in bone/tooth tissue engineering.     

转化生长因子β1/Smad信号通路对大鼠肾系膜细胞基质金属蛋白酶2及其组织抑制因子2表达的影响

目的　探讨转化生长因子 β1(TGF β1) /Smad信号通路对大鼠肾系膜细胞 (MsC)基质金属蛋白酶 2 (MMP 2 )及其组织抑制因子 2 (TIMP 2 )蛋白表达和酶活性的影响。方法　采用脂质体介导法 ,分别将Smad 2 3 7基因瞬时转染体外培养的大鼠MsC ,并用免疫荧光 逆转录 聚合酶链反应 (RT PCR)和Western印迹法检测其转染成功与否 ;再分别用Western印迹 酶谱法或反式酶谱法 ,观察转基因MsC及其在TGF β1作用下MMP 2和TIMP 2蛋白表达和酶活性的改变。 结果　转染Smad 2基因的MsC ,MMP 2和TIMP 2蛋白表达和酶活性均略有升高 ,蛋白表达分别增强 1 4倍和 1 1倍 ;酶活性分别提高 1 4倍和 1 3倍 ,经TGF β1作用后有明显升高 ,蛋白表达分别增加 2 8倍和 3 0倍 (P <0 0 1) ;酶活性分别提高 3 0倍和 1 7倍 (P <0 0 1) ;转染Smad 3基因的MsC ,TIMP 2蛋白表达和酶活性略有升高 ,蛋白表达增强 1 2倍 ,酶活性提高 1 2倍 ,TGF β1作用后升高更为明显 ,蛋白表达增强 2 9倍 ,酶活性提高 1 8倍 ,而MMP 2蛋白表达和酶活性均无明显变化 ;转染Smad 7基因的MsC ,MMP 2和TIMP 2蛋白表达和酶活性均略有下降 ,蛋白表达均降低 1 2倍 ,酶活性均下降 1 2倍 ,在TGF β1作用下更为明显 ,蛋白表达分别     

Binding capacity of in vitro deglycosylated IgA1 to human mesangial cells

IgA nephropathy (IgAN) is the most common glomerular disease and it is characterized by deposition of IgA1 molecules in mesangium. Recent studies had demonstrated that serum and mesangial IgA1 in IgAN were deglycosylated and IgA1 could bind to human mesangial cells (HMC) through a novel receptor. The aim of the current study is to investigate and compare the binding capacities of different in vitro deglycosylated IgA1 on human mesangial cells. Serum IgA1 was purified by jacalin affinity chromatography and then was desialylated (DesIgA1) and/or degalactosylated (Des/DeGalIgA1) with neuraminidase and/or beta-galactosidase. The efficacy of deglycosylations was assessed by Peanut agglutinin (PNA) and Vicia villosa (VV) lectin. The sizes of normal IgA1 and deglycosylated IgA1 were determined by Sephacryl S-300 chromatography and binding capacities to primary HMC were evaluated by radioligand binding assays. Normal IgA1 and deglycosylated IgA1 could bind to HMC in a dose-dependent, saturable manner. The maximal binding capacities and binding sites/cell of DesIgA1 and Des/DeGalIgA were significantly higher than that of normal IgA1. However, more aggregated IgA1 was found in DesIgA1 and Des/DeGalIgA1. Scatchard analysis revealed a similar Kd of normal IgA1 and deglycosylated IgA1. The current study suggested that the binding capacities of DesIgA1 and Des/DeGalIgA1 to HMC were significantly higher than that of normal IgA1, which at least in part was due to more macromolecular IgA1 in deglycoslated IgA1. However, there were no significant differences in the affinities of normal IgA1, DesIgA1 and Des/DeGalIgA1 with HMC. Deglycosylated IgA1 might play an important role in pathogenesis of IgAN.     

Constitutive ERK1/2 activation contributes to production of double minute chromosomes in tumour cells

Double minute chromosomes (DMs) are extrachromosomal cytogenetic structures found in tumour cells. As hallmarks of gene amplification, DMs often carry oncogenes and drug‐resistance genes and play important roles in malignant tumour progression and drug resistance. The mitogen‐activated protein kinase (MAPK) signalling pathway is frequently dysregulated in human malignant tumours, which induces genomic instability, but it remains unclear whether a close relationship exists between MAPK signalling and DMs. In the present study, we focused on three major components of MAPK signalling, ERK1/2, JNK1/2/3 and p38, to investigate the relationship between MAPK and DM production in tumour cells. We found that the constitutive phosphorylation of ERK1/2, but not JNK1/2/3 and p38, was closely associated with DMs in tumour cells. Inhibition of ERK1/2 activation in DM‐containing and ERK1/2 constitutively phosphorylated tumour cells was able to markedly decrease the number of DMs, as well as the degree of amplification and expression of DM‐carried genes. The mechanism was found to be an increasing tendency of DM DNA to break, become enveloped into micronuclei (MNs) and excluded from the tumour cells during the S/G₂ phases of the cell cycle, events that accompanied the reversion of malignant behaviour. Our study reveals a linkage between ERK1/2 activation and DM stability in tumour cells. © 2014 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

ABCE1基因在人肾小球系膜细胞中的表达

ATP结合盒转运子E1(ATP-binding cassette transporter E1,ABCE1)属ATP结合盒转运子基因亚家族成员之一,其表达定位于细胞质及线粒体.该基因在人体各组织器官表达具有特异性.     

VLDL促进脂蛋白脂酶在人肾小球系膜细胞系的表达

目的 探讨人肾小球系膜细胞脂蛋白脂酶（LPL）的表达情况以及极低密度脂蛋白(VLDL)对其表达的影响。方法 用反转录聚合酶链反应（RT-PCR）、western blot和放射性同位素标记的脂质体底物法检测人肾小球系膜细胞系（HMCLs）LPLmRNA表达、蛋白合成及酶活性。western blot检测VLDL对肾小球系膜细胞LPL表达的影响。结果 用HMCLs,在276bp处可扩增出一条hLPL基因特异的条带;在55kd处可检测出LPL蛋白特异的条带;经肝素释放后HMCLs培养液中LPL是有活性的,为（0.959±0.022）U/L。VLDL在一定范围内可时间（0～16h）和剂量（0～100 mg/L）依赖性的刺激HMCLs LPL蛋白表达。结论 在肾小球系膜细胞可表达具有活性的脂蛋白脂酶,且其表达可受VLDL的调节。     

高糖对大鼠肾小球系膜细胞ERK转导通路的影响

目的： 探讨高糖环境下系膜细胞中ERK转导途径的活性变化及其对TGF-β1 mRNA表达的影响。方法： 分离培养大鼠肾脏系膜细胞，调整培养液浓度为以下3组，即正常糖组、高糖组、甘露醇组。分别于干预24 h、48 h、72 h后用免疫细胞化学法和Western blotting法对系膜细胞中磷酸化ERK1/2（pERK1/2）的表达进行定位、定性及半定量分析，用RT-PCR法检测细胞中TGF-β1 mRNA的表达。结果： 高糖组系膜细胞中pERK1/2蛋白的表达明显高于正常糖组，并由胞浆向胞核内转移，随培养时间延长其表达上升(P<0.01)，高糖组TGF-β1mRNA的含量也明显高于正常糖组(P<0.01)，甘露醇组上述指标与正常糖组差异不显著(P>0.05)。结论： 高糖环境下系膜细胞中ERK信号转导通路可被激活，进而使TGF-β1 mRNA表达上调，这可能是糖尿病肾病系膜细胞受损、肾小球硬化的机制之一。     

内皮素-1对人肾小球系膜细胞层黏连蛋白的影响

内皮素-1(endothelin-1,ET-1)是一种强烈的缩血管活性肽,与血管紧张素Ⅱ(Ang Ⅱ)具有很多相似之处,且二者之间具有相瓦促进作用[1].阻断肾素-血管紧张素(RAS)系统已被广泛应用于慢性肾脏病(CKD)的治疗,但是ET系统拮抗剂还未得到重视.本实验通过研究ET-1及其受体拮抗剂(Bosentan)对层黏连蛋白(laminin,LN)代谢的影响,为ET-1受体拮抗剂应用于CKD的治疗提供依据.     

霉酚酸酯对高糖培养下人肾小球系膜细胞MCP-1和FN表达的影响

目的:探讨高糖以及霉酚酸酯(MMF)对人肾小球系膜细胞(HMCs)单核细胞趋化蛋白-1(MCP-1)和纤维连接蛋白(FN)表达的影响。方法:将培养的HMCs分为正常对照组(5 mmol/L葡萄糖);高糖组(30 mmol/L葡萄糖);甘露醇渗透压对照组(5 mmol/L葡萄糖+25 mmol/L甘露醇);高糖+MMF-10组(30 mmol/L葡萄糖+10μg/mL MMF);高糖+MMF-100组(30 mmol/L葡萄糖+100μg/mL MMF),采用RT-PCR检测每组不同时间点(24、48、72 h)MCP-1 mRNA的表达,ELISA法检测培养上清液MCP-1及FN蛋白的表达。结果:高糖组HMCs MCP-1 mRNA、蛋白的表达及FN的分泌较正常对照组显著增加(P<0.01),且48 h表达最高;不同浓度的MMF均能下调MCP-1 mRNA、蛋白及FN的表达(P<0.01);不同浓度的MMF对MCP-1 mRNA、蛋白的表达及FN分泌的抑制程度不同,呈时间剂量依赖性(P<0.05)。结论:MMF可以阻抑MCP-1的表达及FN的分泌,可能对延缓肾小球硬化及间质纤维化有一定作用。