AGEs培养的人肾小球系膜细胞中二氢叶酸还原酶及O_2~-水平

目的:观察晚期糖基化终末产物(AGEs)对人肾小球系膜细胞(HMCs)中二氢叶酸还原酶(DHFR)和超氧阴离子(O-2)水平的影响。方法:在HMCs中加入5.6mmol/L葡萄糖(正常对照组)和200mg/LAGEs(AGEs组),平行培养48h后,采用Western blotting检测两组DHFR蛋白含量,采用二氢乙啶(DHE)法检测两组O-2的水平。结果:与正常对照组比较,AGEs组DHFR蛋白表达显著下调(P<0.05),O-2水平显著上调(P<0.01)。结论:AGEs诱导HMCs产生的O-2可能通过下调DHFR蛋白水平影响四氢生物喋呤(BH4)的生物补救合成途径,导致BH4减少而加重糖尿病肾病(DN)的氧化应激。     

己酮可可碱联合骨髓间充质干细胞降低高糖诱导的肾小球系膜细胞纤维化倾向及糖基化终末产物聚集的体外研究

为探讨己酮可可碱(pentoxifylline,PTX)联合骨髓间充质干细胞(mesenchymal stem cell,MSC)对高糖条件下肾小球系膜细胞纤维化及糖基化终末产物(advanced glycation end product,AGE)聚集的影响,将体外高糖培养的小鼠肾小球系膜细胞分为6个组:正常组、损伤组、MSC组、MSC+PTX 0.1mmol/L组、MSC+PTX 0.3mmol/L组和MSC+PTX 1mmol/L组。MSC组将MSC和肾小球系膜细胞共培养。MSC+PTX 3组在MSC和肾小球系膜细胞共培养时分别加入0.1、0.3和1mmol/L的PTX。采用ELISA检测各组肾小球系膜细胞AGE水平,Western blotting检测各组肾小球系膜细胞中结缔组织生长因子(connective tissue growth factor,CTGF)、果蝇抗同源序列蛋白3(drosophila mothers against decapentaplegic 3,SMAD3)、SMAD7及转化生长因子β(transforming growth factorβ,TGF-β)的表达。结果显示,与正常组比较,损伤组肾小球系膜细胞的AGE水平显著升高(P <0.01)。与损伤组比较,MSC组、MSC+PTX 0.1 mmol/L组、MSC+PTX0.3mmol/L组和MSC+PTX 1mmol/L组肾小球系膜细胞的AGE水平显著降低(P <0.01),加入PTX后肾小球系膜细胞的AGE水平降低得更为显著,且呈现一定的浓度依赖性。与正常组比较,损伤组CTGF、SMAD3及TGF-β的蛋白表达量显著升高(P <0.01),SMAD7表达量显著降低(P <0.01)。MSC+PTX 0.1mmol/L组、MSC+PTX 0.3mmol/L组和MSC+PTX 1mmol/L组的CTGF、SMAD3和TGF-β蛋白表达量显著低于损伤组(P <0.05),但SMAD7蛋白表达量显著高于损伤组(P <0.01),且呈现PTX浓度依赖性。提示PTX联合MSC可能具有通过降低共培养肾小球系膜细胞中AGE的聚集以及多靶点抑制TGF-β/SMAD信号通路来抑制细胞纤维化的潜能,且呈现PTX浓度依赖性。     

糖基化终产物通过其受体诱导人肾小球系膜细胞表达CTGF和FN

目的： 探讨体外培养条件下糖基化终产物（AGEs）对人肾小球系膜细胞(HRMCs）中结缔组织生长因子（CTGF）及纤维连接蛋白（FN）基因表达的影响及其可能的作用机制。方法: 将HRMCs与不同浓度的糖化牛血清白蛋白（AGE-BSA）和牛血清白蛋白（BSA）共同培养,或与同一质量浓度的AGE-BSA和BSA共同培养不同时间,以中和性抗RAGE抗体封闭细胞膜上糖基化终末产物受体（RAGE）;采用免疫印迹法（Western blotting）观察AGEs对HRMCs中RAGE表达的影响,半定量逆转录-聚合酶链反应（RT-PCR）法检测CTGF、FN mRNA的表达。结果: 在HRMCs中存在少量RAGE的表达,AGE-BSA能够诱导HRMCs中RAGE的表达增加,并以时间和剂量依赖方式促进HRMCs中CTGF和FN的表达上调;CTGF、FN的表达水平在加入不同浓度（50、100、200、400 mg/L）的AGE-BSA 作用48 h后以及加入质量浓度为200 mg/L的 AGE-BSA 作用不同时间（12、24、48、72h）后,较相应质量浓度或时间的BSA组和空白对照组均明显升高（P＜0.05）;抗RAGE抗体干预后能够部分抑制AGE-BSA诱导CTGF及FN的表达,而人IgG没有这种作用。结论: AGEs可能通过RAGE诱导CTGF及FN的表达上调,是糖尿病肾病肾脏纤维化的可能机制。     

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.     

盐酸氨基胍对糖基化终产物诱导的人肾小球系膜细胞调节活化蛋白表达的影响

目的探讨盐酸氨基胍对糖基化终产物（AGEs）促进人肾系膜细胞（HRMC）趋化因子RANTES表达和分泌的干预效应。方法常规方法制备糖基化终产物（AGEs-BSA）和盐酸氨基胍干预体外培养的HRMC,收集培养上清和细胞,ELISA法检测上清中RANTES浓度,实时定量RT-PCR检测RANTES mRNA表达水平,western blot检测RANTES蛋白表达。结果盐酸氨基胍干预组HRMC RANTES的mRNA和蛋白表达以及蛋白分泌明显低于AGE-BSA组（P〈0.05）;且降低水平呈浓度依赖性。结论盐酸氨基胍能抑制AGEs诱导的HRMC RANTES的表达和分泌。     

冬凌草甲素调节高糖诱导的人肾小球系膜细胞异常增殖、炎症和纤维化

目的：探讨冬凌草甲素对高糖诱导的人肾小球系膜细胞（HGMCs）增殖、炎症和纤维化的影响,并初步探究其作用机制。方法：高糖联合冬凌草甲素培养HGMCs,CCK8检测细胞增殖,流式细胞术检测细胞凋亡率,RT-PCR和ELISA检测细胞上清液炎症因子水平,免疫荧光检测活性氧（ROS）含量,试剂盒检测超氧化物歧化酶（SOD）和丙二醛（MDA）含量,RTPCR联合Western blot检测TGF-β、纤维粘连蛋白（FN）和α-平滑肌肌动蛋白（α-SMA）水平,Western blot检测TLR4/MyD88和p-P65蛋白水平。结果：与健康对照组相比,模型组细胞增殖、免疫应答和纤维化水平均显著提高（P<0.05）。与模型组相比,10μg/ml和20μg/ml冬凌草甲素组细胞增殖倍数显著降低（P<0.05）,细胞凋亡率显著增高（P<0.05）,TNF-α、IL-6、IL-1β含量显著降低（P<0.05）,ROS和SOD含量升高,MDA含量显著降低（P<0.05）,TGF-β、FN和α-SMA水平显著降低（P<0.05）,TLR4/MyD88和p-P65蛋白水平...     

冬凌草甲素调节高糖诱导的人肾小球系膜细胞异常增殖、炎症和纤维化北大核心CSCD

目的:探讨冬凌草甲素对高糖诱导的人肾小球系膜细胞(HGMCs)增殖、炎症和纤维化的影响,并初步探究其作用机制。方法:高糖联合冬凌草甲素培养HGMCs,CCK8检测细胞增殖,流式细胞术检测细胞凋亡率,RT-PCR和ELISA检测细胞上清液炎症因子水平,免疫荧光检测活性氧(ROS)含量,试剂盒检测超氧化物歧化酶(SOD)和丙二醛(MDA)含量,RTPCR联合Western blot检测TGF-β、纤维粘连蛋白(FN)和α-平滑肌肌动蛋白(α-SMA)水平,Western blot检测TLR4/MyD88和p-P65蛋白水平。结果:与健康对照组相比,模型组细胞增殖、免疫应答和纤维化水平均显著提高(P<0.05)。与模型组相比,10μg/ml和20μg/ml冬凌草甲素组细胞增殖倍数显著降低(P<0.05),细胞凋亡率显著增高(P<0.05),TNF-α、IL-6、IL-1β含量显著降低(P<0.05),ROS和SOD含量升高,MDA含量显著降低(P<0.05),TGF-β、FN和α-SMA水平显著降低(P<0.05),TLR4/MyD88和p-P65蛋白水平显著降低(P<0.05)。结论:冬凌草甲素对高糖诱导的HGMCs增殖、炎症反应、纤维化和氧化应激水平具有调节作用,其作用机制可能与下调TLR4、MyD88和p-P65水平有关。     

抗氧化剂PDTC抑制氧化的低密度脂蛋白诱导的人肾小球系膜细胞NF_(-k)B活化

目的 研究氧化的低密度脂蛋白（Ｏｘ－ＬＤＬ）对体外培养的人肾小球系膜细胞（ＨＭＣ）核因子－ＫＢ（ＮＦ－ＫＢ）活化的影响，以及抗氧化剂毗咯二硫氨基甲酸酯（Ｐ ＤＴＣ）对ＮＦ－ＫＢ活化的抑制作用，探讨ＯＸ－ＬＤＬ介导肾损害的基因调控机制及抗氧化剂ＰＤＴＣ防治脂质肾损害的可能性。方法 将Ｏｘ－ＬＤＬ或ＰＤＴＣ与ＨＭＣ共培养后，提取细胞核蛋白进行凝胶迁移率变动分析（ＥＭＳＡ）检测ＮＦ－ＫＢ的活化，用细胞ＥＬＩＳＡ法检测细胞内ＩＫＢα蛋白含量的变化，反映ＩＫＢα的降解及免疫组化染色检测细胞内的Ｐ６５向核转位。结果 正常对照组未见ＮＦ－ＫＢ活化，当用不同浓度（１０、２５、５０及１００ｍｇ／Ｌ）的Ｏｘ－ＬＤＬ，刺激肾小球系膜细胞 ｌｈ后，均可引起细胞 ＮＦ－ＫＢ活化及 ＩＫＢα降解。与对只组相卜较差异显著（ｐ＜０．０５），以５０ｍｇ／Ｌ 的ＯＸ－ＬＤＬ刺激ＨＭＣ１ｈ，ＮＦ－ＫＢ活化及 ＩＫＢα降解最明显。ＮＦ－ＫＢ活化的同时，伴有Ｐ６５由胞浆向胞核的转位。１００μｍｏｌ／Ｌ ＰＤＴＣ，能明显抑制 ＮＦ－ＫＢ的活化、ＩＫＢα降解（ｐ＜０．０１）及 Ｐ６５的核转位。结论Ｏｘ－ＬＤＬ。能诱导ＨＭＣ的ＩＫＢαａ降解、Ｐ６５的核转位，最终使Ｎ     

藻黄合剂含药血清体外培养人肾小球系膜细胞结缔组织生长因子的表达

背景：结缔组织生长因子是转化生长因子β1 的下游效应因子,其异常表达在肾小球硬化及纤维化发生、发展中起重要作用。 目的：观察藻黄合剂含药血清对肾小球系膜细胞结缔组织生长因子表达的影响。 方法：血清药理学方法制备藻黄合剂低、中、高剂量,空白对照及海昆肾喜阳性对照大鼠含药血清,分别用体积分数10%各含药血清培养基孵育高糖作用下肾小球系膜细胞48 h,另设低糖组为对照。免疫细胞化学和RT-PCR方法检测各组系膜细胞结缔组织生长因子蛋白及mRNA的表达。 结果与结论：结缔组织生长因子蛋白及mRNA表达在高糖组较低糖组明显升高(P < 0.01);藻黄合剂各剂量组结缔组织生长因子蛋白及mRNA表达均低于高糖组,且具有剂量依赖性;藻黄合剂高剂量组与海昆肾喜组比较结缔组织生长因子蛋白及mRNA表达差异无显著性意义(P > 0.05)。提示高糖可诱导肾小球系膜细胞中结缔组织生长因子的表达,而藻黄合剂可抑制高糖条件下肾小球系膜细胞中结缔组织生长因子蛋白及mRNA的表达。     

高糖培养人肾小球系膜细胞对JAK2/STAT1信号蛋白活化的影响

目的:观察高糖对人肾小球系膜细胞(HMCs)Janus酪氨酸激酶2(JAK2)、信号转导和转录活化因子1(STAT1)以及转化生长因子-β1(TGF-β1)和纤维连接蛋白(FN)表达的影响。方法:将HMCs于高糖(30mmol/L)环境下培养不同时间后,Western blotting检测磷酸化JAK2、STAT1(p-JAK2、p-STAT1)水平;RT-PCR检测TGF-β1和FN mRNA的表达;ELISA测定上清液中TGF-β1和FN的含量,同时以低糖组作为对照。结果:与低糖对照组比较,高糖培养HMCsp-JAK2、p-STAT1蛋白明显上调,TGF-β1和FN mRNA表达和蛋白水平显著增加(P<0.01)。结论:高糖能通过激活HMCs中JAK2/STAT1信号途径,促进TGF-β1和细胞外基质分泌。     

高氨基酸血症对肾小球系膜细胞结缔组织生长因子表达的影响及与氧化应激的关系

目的研究高氨基酸血症对肾小球系膜细胞结缔组织生长因子(connective tissue growth factor,CTGF)表达的影响,探讨氧化应激在其中的作用。方法大鼠肾小球系膜细胞分为不同培养环境下的对照组(C组)、高氨基酸组(HA组)、维生素E组(HAE组)。培养24h后用荧光染料2',7'-Dichloroluores-cin diacetate(20μmol/L)测定各组细胞内活性氧产物(reactive oxygen specie,ROS)的生成情况从而反应细胞内氧化应激水平,培养24h后采用RT-PCR检测各组CTGF mRNA表达,培养48h后采用Western印迹检测各组CTGF蛋白的表达。结果HA组氧化应激水平、CTGF mRNA及蛋白的表达均明显高于C组(P<0.05);HAE组其氧化应激水平、CTGF mRNA及蛋白表达较HA组明显降低(P<0.05),且与C组比较差异无统计学意义(P>0.05)。结论高氨基酸血症可使肾小球系膜细胞氧化应激水平升高并产生过多的CTGF,抗氧化剂维生素E可减轻系膜细胞氧化应激及CTGF的表达,提示高氨基酸诱导的CTGF表达增多可能与氧化应激有关。     

IL-10对人肾小球系膜细胞细胞周期负调控蛋白p27的调节

观察白细胞介素 10 (IL 10 )对体外培养的人肾小球系膜细胞 (HMC )增殖影响 ,并探讨IL 10对HMC细胞周期负调控蛋白p2 7的影响 ,旨在了解其调节HMC增殖的内在机制。HMC用含 5 %FCS的RPMI16 4 0培养 ,加入IL 10刺激后 ,应用流式细胞术分别测定HMC细胞增殖周期的变化以及p2 7的水平。结果表明IL 10可抑制血清诱导的HMC增殖 ,IL 10显著减少了HMCG0 /G1期细胞进入S期和G2 /M期 ;2 5ng/mlIL 10明显地上调细胞周期负调控蛋白p2 7水平 ,是血清刺激组的 1 7倍 (P <0 0 5 )。IL 10抑制血清诱导的HMC增殖的作用机制可能部分是通过上调细胞周期负调控蛋白p2 7来实现的 ,提示IL 10在增殖性肾小球肾炎中可能发挥重要的调节作用     

Expression of Toll-Like Receptor 4 in Glomerular Endothelial Cells under Diabetic Conditions

Diabetic conditions promote glomerulosclerosis by mesangial cells but the mechanisms are not fully elucidated. The present study evaluated the expression of toll-like receptor 4 in glomerular endothelial cells in the streptozotocin (STZ)-induced type 1 diabetic mouse (ICR-STZ) and the type 2 diabetic KK/TaJcl mouse which were fed a high fat diet feed (KK/Ta-HF). In the ICR-STZ and KK/Ta-HF almost glomeruli were immunostained with anti-TLR4 but there was no glomerulus immunostained by ani-TLR4 in the control ICR and KK/Ta. Laser-scanning confocal microscopy showed that the TLR4-positive region did not coincide with the podoplanin-positive region but coincide with the PECAM-1- and VE-cadherin-positive regions in the glomeruli of the ICR-STZ and KK/Ta-HF. The in situ hybridization showed that almost signals for TLR4 mRNA were present in the glomerulus of the ICR-STZ and KK/Ta-HF to a stronger extent than in the control ICR and KK/Ta. These suggest that glomerular endothelial cells usually express the TLR4 gene and hyperglycemia in the diabetic condition induces the TLR4 protein expression in the glomerular capillary endothelial cells. Cytokine productions through the TLR signaling pathway in glomerular endothelial cells may allow mesangial cells to produce extracellular matrix proteins in the diabetic milieu.     

Human naive CD4 T cells produce interleukin-4 at priming and acquire a Th2 phenotype upon repetitive stimulations in neutral conditions

The maturation of naive CD4 T cells into interleukin (IL)-4-producing effectors was shown to require the presence of IL-4 at priming, the cellular origin of which remains unclear. We demonstrate here that naive T cells themselves release IL-4 at very low levels that are nevertheless sufficient to promote their development into Th2-like cells. This conclusion is based on three observations: (1) highly purified human naive CD4T cells, of neonatal or adult origin, develop into Th2 effectors upon repetitive cycles of stimulation with anti-CD3 monoclonal antibody (mAb) cross-linked to CD32-B7 transfected L fibroblasts followed by IL-2 expansion; (2) IL-4 protein is readily detectable in the concentrated supernatant fluids of priming cultures performed in the presence of anti-IL-4 receptor mAb; and (3) addition of anti-IL-4 or anti-IL-4 receptor mAb at priming markedly inhibits the acquisition of IL-4- and IL-5-producing capacity while enhancing that of interferon-γ.     

Activation of Cloned Human CD4+ Th1 and Th2 Cells by Blood Dendritic Cells

Dendritic cells (DC) have been reported to be the most potent antigen-presenting cells (APC) for the activation of naive T cells and to be 10–100-fold more potent APC than monocytes (Mφ) in the mixed lymphocyte reaction. In this study the authors compared human blood DC with Mφ and B cells for their ability to activate cloned rye grass allergen Lol p I specific CD4⁺ Th₁ and Th₂ cells. In the presence of Lol  p I, all three types of APC activated Th₁ and Th₂ cells to a similar extent, as shown by T-cell proliferation and interferon-γ, interleukin-2 (IL-2) or IL-4 secretion. However, at low APC : T cell ratios, Mφ were the most potent APC for both Th₁ and Th₂ cells followed in decreasing order by DC and B cells. This hierarchy was observed with APC preparations isolated by negative selection or highly purified by positive selection using fluorescent cell sorting for HLA-DR^high-DC, CD14^pos-Mφ and CD19^pos-B cells. The data demonstrate that, in contrast to what has been reported for naive T cells, human blood DC activate cloned memory Th₁ and Th₂ cells to a similar extent as Mφ and B cells presumably because the requirements for activation of memory type T cells are less stringent than those for naive T cells.     

人PBL及CTLL—2／HIL—4R细胞系对人IL—4增殖应答的特性

本文分析了３０例正常人ＰＲＬ经ＰＨＡ活化的Ｔ细胞对ＩＬ－２及ＩＬ－４的增殖应答特点；及整合有人ＩＬ－４受体ｃＤＮＡ的ＣＴＬＬ－２／ＨＩＬ－４Ｒ细胞系对人ＩＬ－４的特异增殖应答特点。结果表明，正常人经ＰＨＡ活化的ＰＢＬ对ＩＬ－２有良好增殖应答曲线者占９３％，而对ＩＬ－４有良好增殖应答者只占２０％。　ＣＴＬＬ－２／ＨＩＬ－４Ｒ细胞系对人ＩＬ－４呈规律性增殖应答曲线，且应答敏感性高，可测出０．０９ｕ／ｍｌ，可推荐作为测定人ＩＬ－４生物活性的一种准确方法。     

Low Level of O2 Inhibits Commitment of Cultured Mesenchymal Stromal Precursor Cells from the Adipose Tissue in Response to Osteogenic Stimuli

Mesenchymal stromal precursor cells from human lipoaspirate (lMSC) cultured at 5% O₂ formed 50% less mineralized matrix in response to osteogenic induction than cells cultured under standard conditions (20% O₂). After lMSC percultured at 5% O₂ were transferred to normoxic conditions (20% O₂), they produced the same amount of matrix as lMSC permanently cultured at 20% O₂. Hence, hypoxia inhibited the commitment of lMSC under the effect of osteogenic stimuli, which can be important in reparative and regenerative medicine.     

Molecular models of two competitive inhibitors, IL-2δ2 and IL-2δ3, generated by alternative splicing of human interleukin-2

Molecular models of IL-2δ2 and IL-2δ3, two alternative splice variants of human IL-2 without exon 2 and 3, respectively, are described. These alternative splice variants attract particular interest as potential competitive inhibitors of the cytokine. Tertiary structure of IL-2 consists of four-helix bundle including helices A, B, C and D and a β-pleated sheet. Exon 2 encodes the A–B loop (Asn30–Lys49 residues) linking helices A and B running in one direction. Rotation of the helix A around putative centre during the construction of IL-2δ2 model have not produced any significant changes in the hydrophobic core of IL-2 molecule. However, a large hole was formed on the surface of IL-2δ2 molecule instead of A–B loop in IL-2 fold. A high affinity IL-2 receptor is formed by combination of , β, and γ_c chains. Comparison of the model of the receptor bound IL-2 with the model of IL-2δ2 has shown that their β-chain binding sites have minimum differences as distinct from and γ_c chain-binding sites. Exon 3 encodes Ala50–Lys97 fragment which forms helices B and C with their short connecting loop. Model IL-2δ3 consists of helices A and D and long linking loop. This loop was composed of A–B and C–D loops which run in opposite directions in IL-2 structure and contain β-strands making a β-pleated sheet. Conformation of the linking loop relatively to helices A and D was stabilized by creation of a disulphide bond between cysteines 105 and 125. In addition, the hydrophobic residues of β-sheet interact with the hydrophobic surface of A–D helical complex and close the latter from contacts with solution. Comparison of the model of IL-2 bound to receptor with IL-2δ3 model has shown that absence of helices B and C in IL-2δ3 model results in insignificant conformational changes only in residues interacting with γ_c chain of the receptor. The β/γ_c heterodimer is an intermediate affinity receptor of IL-2. Most likely, both IL-2δ2 and IL-2δ3 are naturally occurring IL-2 antagonists since they keep the ability of binding with an intermediate affinity receptor of this cytokine and fail to engage the chain of its high affinity receptor.