角质细胞生长因子及氯化锂诱导毛囊干细胞定向分化中的信号通路

背景:毛囊干细胞的增殖分化受到自身基因及外来信号的共同作用,Wnt/β-catenin信号通路在毛囊毛发发育中起重要作用,但详细机制尚未明确。目的:探讨在角质细胞生长因子及氯化锂干预下,Wnt/β-catenin信号通路在人毛囊干细胞向毛囊乳突细胞或表皮细胞定向分化中的作用及与其他信号分子的相互关系。方法:获取毛囊隆突区干细胞进行培养,检测其生长曲线,观察1×106 L-1、1×107 L-1、1×108 L-1和1×109 L-1培养的毛囊干细胞在不同时间点的增殖效应;使用免疫荧光染色法对毛囊干细胞及其分化细胞进行鉴定。分别以0,0.5,1.5,10,25 mmol/L氯化锂及0,10,25,50,100μg/L角质细胞生长因子诱导毛囊干细胞分化,对比各组细胞的增殖效应,探索促毛囊干细胞分化的最佳氯化锂及角质细胞生长因子浓度。使用RT-PCR检测未处理对照组、10 mmol/L氯化锂组和10μg/L角质细胞生长因子组干预后3,5,7,9 d细胞的β-catenin、APC、GSK-3β、Axin和Lef1的mRNA转录水平。结果与结论:分离培养的毛囊干细胞在体外经多次传代后仍具有很强的增殖能力和多向分化潜能,随氯化锂浓度升高,细胞增殖效应减弱;而随角质细胞生长因子组质量浓度增高细胞增殖能力增强。含有氯化锂的K-SFM条件培养基中毛囊干细胞形态改变明显,各组间有明显差别,氯化锂10 mmol/L时分化比例高,β-catenin表达量增高;而含有角质细胞生长因子K-SFM条件培养基中毛囊干细胞向表皮细胞分化,β-catenin变化不明显。提示氯化锂在促毛囊干细胞分化中,激活Wnt/β-catenin信号通路,抑制降解复合物重要成分GSK-3β的表达下降,促使β-catenin在细胞浆表达增加并转入核内,增加靶基因转录,促使毛囊干细胞向毛囊细胞方向分化。氯化锂10 mmol/L是促毛囊干细胞分化的最佳浓度,但增殖效应减弱。角质细胞生长因子可促进毛囊干细胞向表皮分化,可促进毛囊干细胞增殖和迁移,促进创面再上皮化及创面愈合。氯化锂和角质细胞生长因子促毛囊干细胞定向分化的作用机制可能为激活Wnt/β-catenin信号通路,促使β-catenin表达改变,从而激活Wnt信号通路中Lef介导相关靶基因的转录。     

Wnt/β-catenin通路参与脂肪间充质干细胞对大鼠肾小球系膜细胞增殖的调控

目的探讨脂肪间充质干细胞(ADSC)经Wnt/β联蛋白(β-catenin)通路对肾小球系膜细胞增殖的影响。方法以大鼠ADSC的条件培养基作用于HBZY-1大鼠肾小球系膜细胞,通过流式细胞术分析细胞周期、RNA干扰、实时定量PCR和Western blot等技术分析HBZY-1细胞增殖能力、Wnt信号通路中相关基因和蛋白表达水平的变化。结果在ADSC条件培养基作用下,HBZY-1细胞增殖受到明显抑制,dickkopf WNT信号通路抑制物1(DKK1)mRNA表达水平明显升高,而纤连蛋白(fibronectin)和转化生长因子β1(TGF-β1)的mRNA表达显著降低,同时系膜细胞的β-catenin和Bcl-2蛋白的表达受到明显抑制。ADSC中DKK1 mRNA表达水平显著高于HBZY-1细胞,利用小干涉RNA敲低ADSC的DKK1表达后,其β-catenin蛋白的表达水平显著升高。将干扰后的ADSC条件培养基作用于HBZY-1细胞,可重新增加HBZY-1细胞Wnt信号通路中β-catenin和Bcl-2的蛋白水平。结论 Wnt/β-catenin信号通路可能参与ADSC对HBZY-1肾小球系膜细胞增殖的调控。     

持续Wnt信号通路激活促进胚胎干细胞源造血干细胞的增殖

背景：如何提高胚胎干细胞诱导效率、促进胚胎干细胞源造血干细胞体外增殖成为目前急需解决的课题。目的：以外源性Wnt3a作为诱导剂,激活培养中的小鼠胚胎干细胞Wnt/β-catenin信号通路,观察该通路的激活是否促进胚胎干细胞向造血祖细胞的定向分化。方法：用外源性wnt3a(100 µg/L)持续作用ES-E14TG2a小鼠胚胎干细胞21 d,通过细胞免疫荧光及蛋白免疫印迹检测细胞内β-catenin蛋白含量,QRT-PCR检测Wnt下游靶标基因的表达量来确定经典Wnt/β-catenin信号通路是否被激活,然后采用单层贴壁培养法诱导其向造血干细胞分化,流式细胞仪检测造血发育相关表面标志CD34⁺/Sca-1⁺,同时以QRT-PCR法检测造血相关基因的表达情况。结果与结论：ES-E14TG2a小鼠胚胎干细胞经wnt3a(100 µg/L)连续培养21 d后发现β-catenin蛋白在细胞内积累;Wnt信号通路的下游靶标基因Pitx2、Frizzled、Sox17、Oct4的表达量均出现不同程度的增加,可见经典Wnt/β-catenin信号通路有被激活;单层贴壁培养法诱导其向造血干细胞分化的过程中检测到CD34⁺/Sca-1⁺细胞含量在14 d时占总细胞量高达20.2%,而对照组的仅占11.9%。造血相关基因骨形态发生蛋白4、FLK2及CD34的表达量均增加,而Smad5的表达则明显受到抑制。说明Wnt3a持续作用可激活Wnt/β-catenin信号通路,并促进ES-E14TG2a小鼠胚胎干细胞向造血干细胞的定向分化。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

柚皮苷调控lncRNA MEG3/Wnt/β-catenin信号通路促进炎症来源牙周膜干细胞的成骨分化北大核心CSCD

目的:研究柚皮苷对炎症来源牙周膜干细胞成骨分化的影响及其作用机制。方法:分离培养牙周炎来源的牙周膜干细胞(PPDLSCs)和正常牙周组织来源的牙周膜干细胞(HPDLSCs),PPDLSCs转染小干扰RNA(siRNA)阴性对照组和lncRNA MEG3 siRNA,采用1μmol/L柚皮苷干预PPDLSCs并进行成骨分化诱导,RT-qPCR和Western blot实验检测lncRNA MEG3和成骨分化相关基因OCN、Runx2、ALP的表达,Western blot检测Wnt/β-catenin信号通路相关蛋白GSK3β、p-GSK3β、β-catenin的表达。结果:柚皮苷干预促进PPDLSCs中OCN、Runx2和ALP mRNA和蛋白表达,促进PPDLSCs的成骨分化;与HPDLSCs相比,PPDLSCs中lncRNA MEG3相对表达量降低,柚皮苷干预上调PPDLSCs中lncRNA MEG3的表达;抑制lncRNA MEG3能够抑制PPDLSCs细胞增殖,并减弱柚皮苷对PPDLSCs成骨分化的促进作用;柚皮苷干预抑制PPDLSCs中p-GSK3β、β-catenin蛋白表达,抑制Wnt/β-catenin通路活性,而抑制lncRNA MEG3能够减弱柚皮苷对Wnt/β-catenin通路活性的抑制作用。结论:柚皮苷能够促进PPDLSCs的成骨分化,其作用机制可能与上调lncRNA MEG3表达,抑制Wnt/β-catenin通路活性有关。     

不同浓度骨碎补总黄酮复合可注射骨修复材料对MC3T3-E1成骨细胞作用的实验研究

目的本实验旨在观察中药骨碎补提取物骨碎补总黄酮(AFDR)复合海藻酸基可注射骨修复材料对成骨细胞MC3T3-E1体外培养的影响。方法将成骨细胞株MC3T3-E1随机分为空白对照组、单纯使用海藻酸基可注射骨修复材料组、AFDR0.04mg/L、0.16mg/L、0.64mg/L、1.28mg/L、5.12mg/L 7组,体外复合海藻酸基可注射骨修复材料,以24h和48h为观察时间点,倒置显微镜观察MC3T3-E1细胞形态,台盼蓝拒染法检测MC3T3-E1存活率,MTT法观察细胞增殖效应,碱性磷酸酶(ALP)活性和骨钙素定量检测分别观察不同浓度骨碎补总黄酮促进MC3T3-E1分化作用,采用Von kossa钙化染色法观察其促MC3T3-E1细胞钙化作用。结果①倒置显微镜下观察复合海藻酸基可注射骨修复材料的MC3T3-E1细胞形态,细胞形态呈三角形、多边形、长梭形等,呈集落样生长,无接触抑制,有伪足伸出,胞液透亮,核圆形。AFDR各组不同程度促进成骨细胞的增殖、分化:7组能不同程度的促进成骨细胞的增殖、分化,与空白对照组比较,以0.16 mg/L和0.64mg/L剂量组的成骨细胞增殖数量最多,1.28mg/L,5.12mg/L的AFDR对细胞增殖作用不明显;②MC3T3-E1平均存活率≥90%;③骨碎补总黄酮(AFDR)0.16 mg/L和0.64mg/L剂量组在培养24小时和48小时,其OD值与空白对照组及组间均有显著性差异,可促进MC3T3-E1细胞增殖(P0.05和P0.01);④AFDR 0.16 mg/L和0.64mg/L剂量组能使MC3T3-E1的ALP活性升高(P0.05);⑤AFDR 0.64mg/L剂量组能促进MC3T3-E1骨钙素合成(P0.05);⑥AFDR 0.16 mg/L和0.64mg/L剂量组均可促进细胞钙化(P0.05)。结论 AFDR可显著促进在海藻酸基可注射骨修复材料上MC3T3-E1的增殖、分化和钙化,其作用具有时间依赖和剂量依赖关系。     

TNF-α激活Wnt信号通路促进人结肠癌干细胞侵袭

目的探讨炎症环境下Wnt信号通路对人结肠癌干细胞侵袭的影响。方法以人结肠癌细胞系HT29细胞为材料,用流式细胞荧光分选技术(FACS)分选CD44+CD133+的人结肠癌干细胞;流式细胞术及单细胞克隆形成实验对分选出的干细胞进行鉴定;肿瘤坏死因子α(TNF-α)处理CD44+CD133+HT29细胞建立炎症细胞模型,噻唑蓝(MTT)实验筛选TNF-α作用的最适剂量及最佳作用时间; Wnt信号通路抑制剂Dickkopf相关蛋白1(DKK1)作用于CD44+CD133+HT29炎症细胞,实验分为空白组、TNF-α处理组、加DKK1的TNF-α处理组。MTT实验检测各组细胞增殖情况,Western blot法检测Wnt信号通路中相关蛋白β联蛋白(β-catenin)、细胞周期蛋白D1(cyclin D1)、c-Myc及上皮间质转化(EMT)相关蛋白上皮钙黏素(E-cadherin)、波形蛋白(vimentin)的表达情况,TranswellTM侵袭实验检测各组细胞侵袭情况。结果流式细胞分选术成功分选出结肠癌CD44+CD133+HT29干细胞。MTT实验筛选出TNF-α作用的最适剂量为10 ng/m L,最佳作用时间为48 h。与空白组相比,TNF-α处理组中CD44+CD133+HT29细胞的相对存活率增加,TranswellTM穿膜的细胞数增加,β-catenin、cyclin D1、c-Myc表达升高,E-cadherin表达降低、vimentin表达升高;与TNF-α处理组相比,加DKK1的TNF-α处理组CD44+CD133+HT29细胞的相对存活率降低,TranswellTM穿膜细胞数减少,β-catenin、cyclin D1、c-Myc表达降低,E-cadherin表达升高、vimentin表达降低。结论TNF-α通过激活Wnt信号通路促进结肠癌干细胞的侵袭能力。     

人成骨细胞分化及骨保护素分泌:R-脊椎蛋白1通过Wnt/β-catenin通路的作用

背景:研究表明Wnt/β-catenin信号通路活性受抑是类风湿关节炎骨侵蚀的始动因素,增强该通路有望治疗类风湿关节炎关节破坏。R-脊椎蛋白1(RSpo1)可能是Wnt激活剂,尚无人成骨细胞相关研究。目的:验证R-脊椎蛋白1抑制DKK1促进该细胞的分化成熟。方法:给予S40转染人成骨细胞株h FOB 1.19 Wnt-3a、R-脊椎蛋白1及Wnt信号通路抑制剂DKK1不同刺激,通过检测细胞增殖、碱性磷酸酶活性及骨保护素水平,观察R-脊椎蛋白1在成骨细胞中的作用。结果与结论:R-脊椎蛋白1对hF OB 1.19细胞增殖无影响,Wnt-3a上调碱性磷酸酶活性,与R-脊椎蛋白1共刺激可增强该作用;R-脊椎蛋白1可减少DKK1对h FOB1.19细胞碱性磷酸酶活力的抑制作用。R-脊椎蛋白1可提高骨保护素质量浓度,但R-脊椎蛋白1对骨保护素的增强作用大于DKK1对其的抑制作用。提示R-脊椎蛋白1通过抑制DKK1,参与Wnt/β-catenin信号通路,促进成骨细胞分化成熟,分泌骨保护素。     

骨碎补总黄酮依赖PI3K/Akt通路与牙髓干细胞的成骨分化

背景：PI3K/Akt通路可能在骨碎补总黄酮促成骨分化作用中发挥重要调控作用。 目的：观察骨碎补总黄酮对大鼠牙髓干细胞成骨分化的影响,并对PI3K/Akt通路在其中的作用进行初步探讨。 方法：采用组织块消化法获得大鼠牙髓细胞,克隆化分离培养大鼠牙髓干细胞并进行鉴定。在培养体系中加入不同质量浓度(0.01,0.05,0.1 g/L)的骨碎补总黄酮,观察各组细胞的碱性磷酸酶水平及钙结节形成情况,并用Western Blot法检测各组细胞磷酸化Akt的表达变化。 结果与结论：分离得到的牙髓干细胞的细胞表面标志CD44和CD29呈阳性表达,而CD34表达呈阴性。骨碎补总黄酮组牙髓干细胞的碱性磷酸酶活性、钙结节形成能力和磷酸化Akt蛋白相对表达量增加,较空白对照组差异有显著性意义,且随骨碎补总黄酮质量浓度的增加而升高,表现出一定浓度和时间依赖性。说明骨碎补总黄酮对大鼠牙髓干细胞成骨分化具有促进作用,且该作用可能是依赖PI3K/Akt通路所介导的。     

独活寄生汤拆方通过Wnt/β-catenin信号通路抑制软骨细胞炎症反应

文题释义：Wnt/β-catenin信号通路：是一条在生物进化中极为保守的通路。在正常细胞中，β-catenin只是作为一种细胞骨架蛋白在胞膜处与E-cadherin形成复合体对维持同型细胞的黏附、防止细胞的移动发挥作用。只有当细胞外Wnt信号分子与细胞膜上特异性受体Frizzled蛋白结合激活胞内散乱的蛋白导致GSK-3β失活，进而使β-catenin磷酸化降解，当解离的β-catenin达到一定浓度时细胞功能发生异常，表现为病理状态。独活寄生汤拆方：由中药独活、桑槲寄生、防风、秦艽、细辛、肉桂心组成具有祛风湿、止痹痛的祛湿止痛方，处方比例为3︰2︰2︰2︰2︰2。背景：Wnt/β-catenin信号通路在骨关节炎的炎症反应病理过程中扮演着重要角色，而独活寄生汤拆方可有效抑制软骨细胞的炎症反应，但其具体作用机制尚不明确。有待进一步深入研究。 目的：探讨独活寄生汤拆方是否可以通过调控Wnt/β-catenin信号通路抑制由脂多糖诱导的软骨细胞炎症反应。方法：①取SD雄性大鼠，采用机械Ⅱ型胶原酶消化法获取膝关节软骨细胞，倒置相差显微镜观察软骨细胞的形态结构，Ⅱ型胶原免疫组化鉴定软骨细胞。②用不同质量浓度的独活寄生汤拆方(300，400，500 mg/L)干预由脂多糖(10 μg/L)诱导的软骨细胞炎症模型，干预8 h后，采用酶联免疫吸附(ELISA)法测定各组软骨细胞培养液中白细胞介素1β、肿瘤坏子因子α水平，确定独活寄生汤拆方干预浓度。③将第2代软骨细胞分为4组：空白组含正常培养液；模型组培养液中含10 μg/L脂多糖；独活寄生汤拆方组培养液中含10 μg/L脂多糖和400 mg/L独活寄生汤拆方；抑制剂组培养液中含10 μg/L脂多糖和10 mg/L Dickkopf-1。干预8 h后，采用Western blot法检测β-catenin、Wnt-4、Frizzled-2、GSK-3β、CKI-ε的蛋白表达量。结果与结论：①软骨细胞鉴定：获取的软骨细胞Ⅱ型胶原免疫组化染色胞浆呈棕黄色，具备软骨细胞典型特征；②ELISA结果显示：模型组培养液中白细胞介素1β和肿瘤坏子因子α水平均高于空白组，400 mg/L独活寄生汤拆方干预后两种炎症因子水平较模型组显著降低，所以确定独活寄生汤拆方干预浓度为     400 mg/L；③Western blot结果显示：模型组β-catenin、Wnt-4、Frizzled-2、CKI-ε的蛋白表达量均高于空白组，而GSK-3β蛋白表达量低于空白组；独活寄生汤拆方组和抑制剂组β-catenin、Wnt-4、Frizzled-2、CKI-ε蛋白表达量低于模型组，而GSK-3β蛋白表达量高于模型组。④结果表明：独活寄生汤拆方可以通过调控Wnt/β-catenin信号通路抑制由脂多糖诱导的软骨细胞炎症反应。ORCID: 0000-0003-3530-5683(李慧)中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程     

糖尿病骨质疏松症模型小鼠脂肪干细胞的成骨能力北大核心

背景:长链非编码RNA(long noncoding RNA,LncRNA)-DANCR可调节包括骨代谢的多个生物学过程。课题组基因芯片结果显示糖尿病骨质疏松小鼠脂肪组织中LncRNA-DANCR显著高表达。目的:探究LncRNA-DANCR通过Wnt/β-catenin信号通路对糖尿病骨质疏松小鼠脂肪干细胞成骨能力的影响。方法:分离培养糖尿病骨质疏松小鼠和正常对照小鼠脂肪干细胞,成骨诱导3 d后,采用qRT-PCR、Western blot检测LncRNA-DANCR、Wnt信号分子β-catenin以及成骨转录因子(RUNX2、OPN)的表达。设计LncRNA-DANCR特异性siRNA转染糖尿病骨质疏松小鼠脂肪干细胞,成骨诱导3 d后,采用qRT-PCR、Western blot和碱性磷酸酶染色检测Wnt信号分子β-catenin、成骨转录因子(RUNX2、OPN)的表达以及成骨能力改变。结果与结论:①成骨诱导3 d后,糖尿病骨质疏松小鼠脂肪干细胞的LncRNA-DANCR表达水平显著高于正常对照小鼠脂肪干细胞,Wnt信号分子β-catenin和成骨转录因子RUNX2、OPN的表达显著低于正常对照小鼠脂肪干细胞;②siRNA转染糖尿病骨质疏松小鼠脂肪干细胞成骨诱导3 d后,β-catenin以及RUNX2、OPN显著高表达,成骨能力增强;③结果表明,LncRNA-DANCR通过抑制Wnt/β-catenin信号通路降低糖尿病骨质疏松小鼠脂肪干细胞的成骨能力,沉默LncRNA-DANCR可恢复其成骨能力。     

3-Hydroxy-3-Methylglutaric Aciduria

3-Hydroxy-3-methylglutaric aciduria was found in a newborn infant whose parents are first cousins. The patient presented at 5 days of life with hyperammonemia, hypoglecemia, and metabolic acidosis. There was no ketonuria. Diagnosis was made by analysis of the pattern of organic acids excreted in the urine. A profound deficiency in activity of 3-hydroxy-3-methylglutaryl-coenzyme A lyase was found in cultured skin fibroblasts. The parents had intermediate levels of enzyme activity.     

DNM3OS Facilitates Ovarian Cancer Progression by Regulating miR-193a-3p/MAP3K3 Axis

PurposeLong non-coding RNAs (lncRNAs) are essential regulators in the development of ovarian cancer (OC). Nonetheless, the function of lncRNA DNM3 opposite strand/antisense RNA (DNM3OS) in OC remains unclear. This work aimed to investigate the biological roles and underlying mechanisms of DNM3OS in OC.Materials and MethodsQuantitative real-time polymerase chain reaction was conducted to examine DNM3OS, microRNA (miR)-193a-3p, and mitogen-activated protein kinase 3 (MAP3K3) mRNA expression in OC tissues and cell lines. Kaplan-Meier survival analysis was employed to analyze the relationship between DNM3OS expression and the prognosis of OC patients. Cell counting kit-8, 5-ethynyl-2′-deoxyuridine, and transwell experiments were conducted to monitor cell proliferation, migration, and invasion, respectively. Western blot was applied to examine epithelial-mesenchymal transition associated protein (E-cadherin and N-cadherin) expression. Luciferase reporter gene and RNA immunoprecipitation experiments were performed to confirm the relationships among DNM3OS, miR-193a-3p, and MAP3K3. Pearson''s correlation analysis was adopted to analyze the correlations among DNM3OS, miR-193a-3p, and MAP3K3 mRNA.ResultsDNM3OS expression was remarkably increased in OC tissues and cell lines, which was associated with the unfavorable prognosis of the patients. DNM3OS overexpression enhanced OC cell proliferation, migration, and invasion; suppressed E-cadherin protein expression; and facilitated N-cadherin protein expression, while the transfection of miR-193a-3p mimics had the opposite effects. DNM3OS directly interacted with miR-193a-3p, and miR-193a-3p targeted MAP3K3 by directly binding to 3′UTR. DNM3OS could up-regulate the expression of MAP3K3 via repressing miR-193a-3p expression.ConclusionDNM3OS, as an oncogenic lncRNA, increases the malignancy of OC cells via regulation of an miR-193a-3p/MAP3K3 axis.     

Covalent binding of guanine nucleotides to the CD3-γ chain of the T cell receptor/CD3 complex

In a search for proteins involved in signal transduction through the T cell receptor (TcR/CD3 complex), a recently developed highly efficient method for labeling of nucleotide binding proteins in permeabilized cells was applied. Here, we report that human CD3-γ could be labeled by periodate-oxidized [α-³²P] GTP (GTP_oxi). In contrast to GTP_oxi labeling of CD3-ξ, (Peter, M. E., Hall, C, Ruhlmann, A., Sancho, J. and Terhorst, C, EMBOJ. 1992. 11: 933), GTP-specific labeling of CD3-γ reached a maximum when nucleotides were added 60 min prior to the cross-linking reaction. As CD3-γ did not contain a known consensus sequence for nucleotide binding and since labeling kinetics of CD3-γ coincided with those of cytosolic GTP-binding proteins, labeling may have been caused by a GTP-binding protein. This putative protein was not T cell specific because labeling of CD3-γ could also be achieved when expressed in the endoplasmic reticulum of Chinese hamster ovary (CHO) cells. In CHO cells, labeling by GTP_oxi took place only when CD3-γ was associated with CD3-ξ, whereas labeling could not be established upon association of CD3-γ with CD3-δ or TcR α. The observation that CD3-γ was labeled without leaving the endoplasmic reticulum led to the hypothesis that the association of CD3-γ with a GTP-binding protein might be involved in an early step of the TcR/CD3 complex formation or transport.     

Human γδ T Cells Express a Higher TCR/CD3 Complex Density Than αβ T Cells

The aim of our study was to compare CD3 expression on γδ T cells and αβ T cells in human patients. The antigen density of TCR and CD3 on both subsets was assessed by a quantitative method in eight patients. In parallel, we developed and validated a reliable direct tricolor staining protocol that we tested on samples from hospitalized and healthy individuals (n = 60). Our results demonstrate that human γδ T cells constitutively express approximately twofold more of the TCR/CD3 complex than αβ T cells. We suggest that this enhanced expression of the TCR/CD3 complex could contribute to the higher reactivity of γδ T cells compared to αβ T cells. These clinical laboratory results confirm the fundamental data described elsewhere. γδ T cells deserve further clinical investigations to understand their precise role in human immunity.     

神经肽Y促进3T3L1前脂肪细胞的增殖和分化

目的:观察神经肽Y对3T3L1前脂肪细胞增殖和分化的影响,并对其机制进行初步探讨。方法:3T3-L1细胞由3-异丁基-1-甲基黄嘌呤(3-isobutyl-1-methylxanthine,IB-MX)、胰岛素和地塞米松联合诱导分化,2 d后将细胞分为空白对照组(未加任何诱导剂组)、经典诱导组(胰岛素诱导)和NPY干预组(10-8、10-9、10-10mol/L NPY)。培养的第7、12天用相差显微镜观察各组细胞形态的变化,培养第12天用油红O染色观察脂肪细胞分化程度。MTT检测细胞增殖。Western blot检测脂肪细胞分化相关基因过氧化物体增殖剂活化受体-γ(peroxisome proliferator-activated receptor gamma,PPAR-γ)、CAAT/增强子结合蛋白-α(CCAAT/enhancer-bind-ing protein-α,C/EBP-α)蛋白的表达。结果:10-8mol/L NPY能促进3T3-L1细胞的分化。10-9mol/L NPY,10-8mol/L NPY均能促进3T3-L1细胞增殖。10-8mol/L NPY增加C/EBPα、PPARγ的表达。结论:NPY促进3T3L1前脂肪细胞的增殖和分化,其机制可能与上调PPARγ、C/EBPα的表达有关。     

Evaluation of Histone 3 Lysine 27 Trimethylation (H3K27me3) and Enhancer of Zest 2 (EZH2) in Pediatric Glial and Glioneuronal Tumors Shows Decreased H3K27me3 in H3F3A K27M Mutant Glioblastomas

H3F3A mutations are seen in ～30% of pediatric glioblastoma (GBMs) and involve either the lysine residue at position 27 (K27M) or glycine at position 34 (G34R/V). Sixteen genes encode histone H3, each variant differing in only a few amino acids. Therefore, how mutations in a single H3 gene contribute to carcinogenesis is unknown. H3F3A K27M mutations are predicted to alter methylation of H3K27. H3K27me3 is a repressive mark critical to stem cell maintenance and is mediated by EZH2, a member of the polycomb‐group (PcG) family. We evaluated H3K27me3 and EZH2 expression using immunohistochemistry in 76 pediatric brain tumors. H3K27me3 was lowered/absent in tumor cells but preserved in endothelial cells and infiltrating lymphocytes in six out of 20 GBMs. H3K27me3 showed strong immunoreactivity in all other tumor subtypes. Sequencing of GBMs showed H3F3A K27M mutations in all six cases with lowered/absent H3K27me3. EZH2 expression was high in GBMs, but absent/focal in other tumors. However, no significant differences in EZH2 expression were observed between H3F3A K27M mutant and wild type GBMs, suggesting that EZH2 mediated trimethylation of H3K27 is inhibited in GBM harboring K27M mutations. Our results indicate that H3F3A K27M mutant GBMs show decreased H3K27me3 that may be of both diagnostic and biological relevance.     

应用组织芯片研究Pim-3、p-STAT3在胰腺癌中的表达及临床意义

目的 探讨Pim-3、p-STAT3蛋白在胰腺导管腺癌组织中的表达情况及生物学行为意义.方法 应用组织芯片和免疫组化的方法,检测88例人胰腺导管腺癌组织和11例非癌组织中Pim-3、p-STAT3蛋白的表达,并分析其与临床病理特征及患者预后的关系.结果 在88例胰腺癌组织中Pim-3、p-STAT3的阳性表达率分别为76.1%和75.0%,在非癌胰腺组织内均为阴性表达.Pim-3在肿瘤细胞的胞质内表达,p-STAT3在肿瘤细胞的胞核与胞质内表达,两者的表达与胰腺癌的临床分期、淋巴结转移相关(P<0.01),与患者年龄、性别、肿瘤大小、位置和病理学分级无关(P>0.05),且其之间成正相关(r=0.416,P<0.01).Kaplan-Meier生存分析结果显示,胰腺癌组织中Pim-3、p-STAT3表达阳性的患者生存时间缩短.Cox多因素相关分析表明Pim-3和p-STAT3阳性表达是影响患者生存期的独立预后因素(分别P=0.003和P=0.015).结论胰腺癌中Pim-3、p-STAT3的阳性表达与肿瘤临床分期和淋巴结转移密切相关,且两者均可作为胰腺癌患者预后不良的判断因子.