体外诱导人脐带华通胶间充质干细胞向内皮细胞分化过程中APJ表达变化

目的研究人脐带华通胶间充质干细胞（human umbilical cord Wharton′s Jelly mesenchymal stem cells,HUW MSCs）体外诱导向内皮细胞分化过程中表面APJ受体表达的变化,探讨APJ是否可作为鉴定内皮细胞的早期细胞表面标志物。方法剖宫产取脐带后分别用酶消化和组织贴壁法培养获得脐带华通胶间充质干细胞,用酶消化法获得人脐静脉内皮细胞（human umbilical vein endothelial cells,HUVECs）。取2×107第2代HUW MSCs用单克隆APJ APC荧光抗体标志后行流式分选,测定HUW MSCs实验前细胞表面表达APJ的水平。实验分3组：诱导组MSCs用含血管内皮细胞生长因子5 μg/L、碱性成纤维细胞生长因子10 μg/L、表皮生长因子10 μg/L和10%胎牛血清（fetal bovine serum,FBS）M199培养基培养;共同培养组MSCs先与HUVECs在Transwell 6孔培养板中,用含10%FBS的M199培养5~7 d后转入25 cm2培养瓶中继续培养,培养液为含10%FBS的M199和培养1 d内皮细胞的M199（2∶1）混合培养基;单纯培养组细胞培养基为含10% FBS的M199。培养周期为14 d。分别于第7、10、14天流式检测各组细胞APJ表达水平,同时检测内皮细胞表面APJ水平作为阳性对照。另外于第7、14天检测3个实验组、内皮细胞组、HUW MSCs组内皮细胞早期标志物CD309表达变化情况,比较各实验组之间APJ与CD309变化趋势。结果HUW MSCs流式分选出5×103APJ+ HUW MSCs,表面表达APJ基本呈阴性。诱导组、共同培养组和单纯培养组细胞形态均较HUW MSCs有显著改变,诱导组呈圆形、线性、网状,共同培养、单纯培养组细胞呈卵圆形、长梭形。另外,诱导组生长最快,增殖能力最强;单纯培养组次之;共同培养组细胞生长缓慢,增殖能力最弱。第7、10、14天,3组细胞CD309表达分别为诱导组18%、26%和88%,共培养组05%、25%和47%,单纯培养组03%、21%和27%。第7、10、14天各组APJ阳性表达率分别为诱导组05% 、09%和52%,共培养组04%、08%和30%,单纯培养组02%、06%和21%。结论HUW MSCs表面APJ表达基本呈阴性,HUW MSCs向内皮细胞诱导分化过程中APJ表达逐渐上调,与内皮细胞早期标志物CD309变化趋势基本一致,可作为早期内皮细胞鉴定的标志物。     

脐带全层源间充质干细胞分离培养及向成软骨细胞分化的实验研究

目的从人脐带全层中分离培养间充质干细胞(MSCs),并进行成软骨诱导分化,为组织工程软骨和软骨损伤后修复提供种子细胞。方法采用胶原酶消化法从脐带全层中分离培养间充质干细胞,显微镜下观察细胞形态,细胞计数法绘制细胞生长曲线,采用流式细胞仪检测细胞周期及细胞表型,采用微团细胞培养在软骨诱导液中向软骨细胞分化,阿尔辛蓝及甲苯胺蓝染色检测细胞分化情况,RT-PCR法检测诱导后细胞表达聚集蛋白聚糖(ACAN)基因情况。结果人脐带全层来源的MSCs呈成纤维样形态漩涡状贴壁生长,细胞高表达HLA-I类分子、CD73、CD90、CD166及CD105,不表达CD34、CD45、CD14、CD31、CD80、CD86及HLA-DR。细胞诱导分化21d后,阿尔辛兰及甲苯胺蓝染色阳性;RT-PCR检测诱导后的细胞表达ACAN,而对照组无表达。结论人脐带全层为成体MSCs提供一种新而方便的来源,人脐带间充质干细胞(hucMSCs)体外培养能够向软骨细胞分化。     

人脐带源和胎盘源间充质干细胞的生物学特性比较

目的：探讨人脐带和胎盘来源间充质干细胞（ MSCs）的分离培养和生物学性状的差异,为MSCs的临床应用提供选择依据。方法利用组织贴壁法分离培养脐带MSCs,酶消化法分离培养胎盘MSCs。传代培养后于倒置显微镜下观察两种不同来源的MSCs的细胞形态,流式细胞仪检测两者表面标志物表达的差异,通过细胞周期和群体倍增时间测定比较两者生长增殖能力,体外成骨和成脂诱导比较其分化能力。结果胎盘MSCs和脐带MSCs为贴壁生长、形态均一的成纤维样或长梭形外观,两种细胞均高表达CD90、CD105,不表达CD34、CD45、HLA-DR。胎盘MSCs的群体倍增时间为40．8 h,52．12％处于G0／G1期,脐带MSCs的群体倍增时间为39．5 h,57．50％处于G0／G1期,表明两者增殖能力旺盛,且无明显差异;两者在体外均可诱导分化成骨细胞和脂肪细胞。结论胎盘源MSCs具有与脐带源MSCs相似的生物学特性,两者均可作为临床治疗用细胞或组织工程的种子细胞。     

aFGF重组腺病毒体外诱导血管新生的实验研究

促血管生长因子可以刺激内皮细胞分裂、分化，诱导血管新生。为探讨其基因转染是否具有相同的作用，作者用构建好的携带人酸性成纤维细胞生长因子（aFGF）DNA的重组腺病毒载体（Ad.aFGF）转染人脐静脉内皮细胞（HUVECs）。免疫荧光染色表明，转染了Ad.aFGF的HUVECs有明显的aFGF表达；ELISA检测显示aFGF能分泌至细胞外；MTT实验显示Ad.aFGF转染后HUVECs显著增生，并且当它们种植于Matrigel基质时可分化形成毛细血管样结构，对照组则无此现象。这些结果说明Ad.aFGF在体外具有促进血管新生的作用，这为其应用于体内刺激侧支血管的生长提供了实验依据。     

体外连续传代培养脐带间充质干细胞染色体核型的稳定性

目的分析不同代次人脐带间充质干细胞（umbilical cord mesenchymal stern cells,UC—MSCs）的染色体核型,初步评价UC—MSCs在体外连续传代培养过程中染色体结构的稳定性。方法采用胶原酶消化法分离UC—MSCs,贴壁培养传代,通过细胞形态、免疫表型及多向分化潜能等生物学特性进行鉴定,利用G显带分析第3、5、7代细胞的染色体核型。结果染色体核型分析显示,第3、5、7代UC-MSCs为正常二倍体核型,G显带未见染色体结构异常。,UC—MSCs呈成纤维样形态生长,高表达CD73、CD90、CDl05,不表达CD34、CIM5、CD40、CD80、CD86、CDl54、HLA—DR;在特定的体外诱导条件下可以向骨、脂肪、软骨分化。结论UC-MSCs在体外连续传代培养7代以内染色体结构稳定,为临床应用UC—MSCs的安全性提供了遗传学方面的实验依据。     

bFGF对辐射诱导的血管内皮细胞凋亡的作用

目的：研究碱性成纤维细胞生长因子(bFGF)对辐射诱导的血管内皮细胞凋亡的作用。方法：以^60Coγ射线照射法建立猪主动脉内皮细胞株PAE(porcine aortic endothelial cells)和原代培养的人脐带静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)调亡模型。以流式细胞术[膜联蛋白(annexin)-V-FTTC PI标记]评价细胞凋亡率，观察不同浓度的bFGF对细胞凋亡的影响。结果和结论：bFGF对辐射诱导的血管内皮细胞凋亡有明显的抑制作用。     

脂肪干细胞修复辐射诱导的肠血管损伤研究

目的 评价人源脂肪干细胞对辐射诱导的肠血管损伤的修复作用。方法 选用成年雄性SD大鼠,共34只,给予全腹部15 Gy X射线照射。造模后,取其中17只给予P6代人源脂肪干细胞腹腔注射治疗（Ad-MSC治疗组）;另17只大鼠给予双磷酸盐缓冲液（PBS）腹腔注射治疗（PBS溶剂对照组）。照射后第10天,流式细胞分析绒毛内CD31阳性内皮细胞的数量,免疫荧光染色分析新生的血管内皮细胞,免疫组织化学染色分析血管结构的连续性;并提取受照小肠组织总RNA,实时荧光定量PCR检测受照组织内基质细胞起源因子-1（SDF-1）、血管内皮细胞生长因子（VEGF）、碱性成纤维细胞生长因子（bFGF）以及血管内皮细胞生长因子受体（Flk-1）的表达量。检测Ad-MSC治疗组的受损小肠内新生的内皮细胞来源。结果 与PBS溶剂对照组相比,Ad-MSC能够显著增加受损组织内CD31阳性内皮细胞数量（t=12.15,P<0.05）,提高受损组织内的血管密度（20 d：t=10.33,P<0.05;30 d：t=32.85,P<0.05）,上调血管生成基因VEGF、bFGF、Flk-1以及SDF-1的表达量（t=10.34、11.25、6.73、6.73,P<0.05）。维持受损部位小肠绒毛内的血管完整,并促进CD31阳性造血干/祖细胞向血管内皮细胞的分化,加速受损部位血管的新生。结论 人源脂肪干细胞通过发挥促血管新生的作用来修复辐射诱导的肠血管损伤。     

骨实质来源间质干细胞对博莱霉素诱导小鼠肺损伤的保护作用

目的 观察小鼠骨实质来源间质干细胞(M9Cs)对博莱霉素诱导的小鼠肺损伤的保护作用.方法 分离培养小鼠骨实质MSCs,通过流式细胞术和诱导分化培养,鉴定其免疫表型和分化潜能.56只雌性C57BL/6小鼠分为8组(每组7只):正常对照组,马利兰(BUS)组,博来霉素(BLM)组,马利兰 博来霉素(BLM BUS)组,博来霉素 MSCs(BLM MSCs)组,马利兰 博来霉素 MSC(BLM BUS MSCs)组;其中,BLM MSCs组和BLM BUS MSCs组根据给予细胞数量不同再分为两个亚组:BLM MSCs 1组(输注5×105个MSCs)和BLM MSCs 2组(输注205X105个MsCs);BLM BUS MSCs 1组(输注5×105个MCSs)和BLM BIJS MSCs 2组(输注2.5×105个MSCs).细胞输注后14d处死小鼠,分析肺组织病理变化和羟脯氨酸含量.结果 小鼠骨实质MSCs为成纤维样细胞,免疫表型为Sca-1、CD44、CD29、CDl05阳性,CEB4、CIM5、CD11b、CD31阴性,在体外能够分化为脂肪细胞和成骨细胞.经静脉输注骨实质MSCs能够减轻博莱霉素诱导的小鼠肺损伤;在BLM MSCs组,输注2.5×105 MSCs较5×105MSCs能更明显地改善肺损伤;BLM BUS MSCs组与BLM MSCs组比较,肺组织病变明显减轻.正常对照组、BUS组、BLM组、BLM BUS组、BLM MSCsl组、BLM MSCs 2组、BLM BUS MSCs 1组、BLM BUs MSCs 2组小鼠肺组织羟脯氨酸含量分别为0.72±0.05、0.79±0.10、1.37±0.09、1.22±0.16、1.24±0.14、1.01±0.15、1.03±0.19、0.88±0.12μg/mg.与正常对照组比较,BLM组和BLM BUS组羟脯氨酸含量明显上升(P<0.01),BLM MSCs组、BLM BUS MSCs组(MSCs输注组)分别与BLM组、BLM BUS组(阳性对照组)相比,羟脯氨酸含量明显下降(P<0.01);而在BLM BUS MSCs组的肺组织羟脯氨酸含量均低于BLM MSCs组(P<0.01).结论 小鼠骨实质MSCs具有间充质干细胞的特征;经静脉输注骨实质MSCs对博莱霉素诱导的小鼠肺损伤具有保护性作用;骨实质MSCs在肺内的作用与输注细胞数量有关;在博莱霉素诱导肺损伤后,马利兰与骨实质M9Cs共同作用有助于减轻肺泡炎和肺纤维化的程度.     

肝细胞生长因子与表皮细胞生长因子联合诱导大鼠骨髓间充质干细胞分化为类肝细胞

目的探讨肝细胞生长因子（HGF）与表皮细胞生长因子（EGF）联合诱导大鼠骨髓间充质干细胞（MSCs）分化为类肝细胞的可行性。方法取大鼠股骨骨髓,用直接贴壁法分离纯化Mats并体外传代,实验组用HGF（20mg／m1）＋EGF（10mg／m1）对体外培养的Mscs进行诱导分化。细胞免疫化学法及流式细胞仪对培养的MSCS进行鉴定。RT-PCR检测诱导后慨的AFP、AIb、CK-18的mRNA表达。电镜观察诱导细胞的超微结构。结果贴壁的MSCs单个存在或形成克隆,细胞形态比较均一,为长梭形,7～10天达汇合。免疫细胞化学及流式细胞仪均证明培养的细胞为MSCs。实验组MSCS在培养21天时表现为类肝细胞的形态特点。RT-PCR：AFP mRNA在第7天呈阳性表达,AIb mRNA及CK-18 mRNA开始即有表达,21天增强。电镜观察见诱导21天的Mats形态结构与肝细胞相吻合。结论Mats在体外容易分离培养和扩增,HGF＋EGF可诱导MSCs向类肝细胞分化,为细胞移植治疗肝衰竭提供新的探索思路。     

去舒地尔对人骨髓间充质干细胞向表皮细胞分化的影响

目的 探讨HA-1077（fasuclil，法舒地尔）对人骨髓间充质干细胞（MSCs）分化为表皮细胞的影响。方法 采用直接贴壁法培养并扩增人胚胎股骨骨髓干细胞，免疫细胞化学及流式细胞仪进行表面标志的检测。设对照组、诱导组、HA-1077诱导组1、HA-1077诱导组2，采用免疫细胞化学及流式细胞仪对各组细胞角质蛋白表达变化进行检测，观察其对MSCs分化为表皮细胞的影响。结果 采用直接贴壁法可以获得大量高纯度的人骨髓MSCs，分组培养后第2天开始出现少量细胞角质蛋白阳性表达细胞，随着时间延长，阳性率逐渐提高。7天后流式细胞仪显示单纯诱导组及HA-1077诱导组CK5／8、CKl0／13、CK19阳性率均远高于诱导组（P〈0．01）。结论 HA-1077可能通过抑制Rho-ROCK途径的激活从而促进MSCs体外培养中角蛋白表达的显著提升，Rho-ROCK途径可能在促进MSCs分化为表皮细胞过程中起着重要调控作用。     

Cell death pathways in directly irradiated cells and cells exposed to medium from irradiated cells

Abstract

Purpose: The aim of this study was to compare levels of apoptosis, necrosis, mitotic cell death and senescence after treatment with both direct radiation and irradiated cell conditioned medium.

Materials and methods: Human keratinocytes (HaCaT cell line) were irradiated (0.005, 0.05 and 0.5 Gy) using a cobalt 60 teletherapy unit. For bystander experiments, the medium was harvested from donor HaCaT cells 1 hour after irradiation and transferred to recipient HaCaT cells. Clonogenic assay, apoptosis, necrosis, mitotic cell death, senescence and cell cycle analysis were measured in both directly irradiated cells and bystander cells

Results: A reduction in cell survival was observed for both directly irradiated cells and irradiated cell conditioned medium (ICCM)-treated cells. Early apoptosis and necrosis was observed predominantly after direct irradiation. An increase in the number of cells in G2/M phase was observed at 6 and 12 h which led to mitotic cell death after 72 h following direct irradiation and ICCM treatment. No senescence was observed in the HaCaT cell line following either direct irradiation or treatment with ICCM.

Conclusion: This study has shown that directly irradiated cells undergo apoptosis, necrosis and mitotic cell death whereas ICCM-treated cells predominantly undergo mitotic cell death.     

凋亡素选择性诱导肿瘤细胞凋亡及其分子机制

来源于鸡贫血病毒的凋亡素能够选择性地诱导肿瘤细胞凋亡,且不依赖于ｐ５３介导,对ｂｃｌ－２过表达不敏感的特点,使其成为一种非常有前景的抗肿瘤剂。该文介绍了凋亡素诱导细胞凋亡的作用特点,并对其凋亡选择性诱导研究的分子机制进行了探讨。     

受照脑胶质瘤细胞诱导神经干细胞旁效应

目的 探讨受照脑胶质瘤细胞U251是否可通过在未受照神经干细胞（NSCs）中产生旁效应从而影响神经干细胞的增殖、干性及分化等特性。方法 将细胞分为NSCs组、NSCs+U251组（与U251共培养的NSCs）和NSCs+受照U251组（与10 Gy X射线照射后的U251共培养的NSCs）。采用插入式小室共培养U251和NSCs。通过细胞计数、测量神经球直径等方法评估NSCs增殖、成球能力的变化;采用免疫荧光实验检测Nestin蛋白的表达评估NSCs干性维持能力的变化;检测Tuj1、GFAP蛋白的表达、测量分化后神经元细胞的树突数目、轴突长度以及胶质细胞突起终端数、突起长度等评估神经干细胞分化能力的变化情况。结果 NSCs+受照U251组的细胞数量明显低于NSCs+U251组（t=2.52,P<0.05）;NSCs+受照U251组的Nestin阳性率和成球能力明显低于NSCs+U251组（t=-3.50,P<0.05）;NSCs+受照U251组向神经元和胶质细胞（t=6.09,P<0.05）分化的比例和程度也明显低于NSCs+U251组。结论 受照胶质瘤细胞可通过电离辐射旁效应显著抑制未受照神经干细胞的增殖、干性和分化能力。     

新生大鼠肌源性干细胞跨胚层分化为胰岛素分泌细胞的研究

目的探讨新生大鼠肌源性干细胞(MDSCs)在体外跨胚层转分化为胰岛素分泌细胞(IPCs)的可能性。方法提取新生大鼠MDSCs原代细胞,差速贴壁培养后行Desmin免疫细胞化学鉴定。然后将细胞分为3组:胰腺提取液诱导组、化学方法诱导组、空白对照组,分别诱导并同期观察细胞的生长形态,采用双硫腙(DTZ)染色鉴定胰岛素分泌细胞,RT-PCR方法检测诱导后细胞的基因表达情况。结果获得高纯度的MDSCs,且Desmin免疫细胞化学鉴定呈阳性。胰腺提取液诱导组诱导后4d,相差显微镜下可见细胞团结构,诱导后6d呈半贴壁状态,诱导后12d形成典型的胰岛样细胞团,较化学方法诱导组诱导时间缩短3d。RT-PCR检测显示:胰腺提取液诱导组诱导6d后可检测到胰岛前体细胞相关基因Ngn3、nestin、PDX-1的表达;诱导12d后可检测到胰岛素基因的表达,但未检测到Ngn3、nestin、PDX-1的表达。结论胰腺提取液可模仿胰岛细胞发育的微环境,并诱导大鼠MDSCs跨胚层分化为胰岛素分泌细胞。     

Stable radioresistance in ataxia-telangiectasia cells containing DNA from normal human cells

SV40-transformed ataxia-telangiectasia (AT) cells were transfected with a cosmid that contains a normal human DNA library and a selectable marker, the neo gene, which endows successfully transformed mammalian cells with resistance to the antibiotic G418. After a three-part selection protocol for G418 resistance and radioresistance, a cell line stably resistant to ionizing radiation was recovered. Cells from this line were irradiated with 50 Gy of X-rays and fused with non-transfected AT cells. Among the G418-resistant colonies recovered was one that was stably resistant to radiation. Resistance to ionizing radiation of both the primary transfectant line and its fusion derivative was intermediate between that of AT cells and normal cells, as assayed by colony-forming ability and measurement of radiation-induced G2 chromatid aberrations; both cell lines retained AT-like radioresistant DNA synthesis. These results suggest that, because radioresistance in the transfected cells was not as great as that in normal human cells, the two hallmarks of AT, radiosensitivity and radioresistant DNA synthesis, may still be the result of a single defective AT gene.     

Mononuclear cells in subcutaneous haemorrhage with special consideration of myeloid percursor cells

Various hematogenous markers were used to differentiate and quantify the types of mononuclear cells present in subcutaneous haemorrhages. Fifty samples of subcutaneous bleeding with a survival time of a few minutes to more than 48 hours were studied. The various cell types were detected using the following stains: Naphthol AS-D chloracetate esterase for myeloid cells, including mast cells; (alpha1-antichymotrypsin for monocytes/macrophages; UCHL1 for T-lymphocytes; and L26 for B lymphocytes. The percentage of monocytes/macrophages was found to increase in dependence on survival time, whereas T-lymphocytes declined. Within minutes of injury neutrophilic granulocytes had emigrated into the surrounding tissue and mast cell degranulation had occurred within the haemorrhagic zone. Esterase-positive mononuclear cells, namely metamyelocytes, were detected within minutes after injury and were still present after survival times exceeding 48 hours; however, no dependence on survival time or cause of death was found. Although the increasing number of monocytes/ macrophages and T-lymphocytes was expected, the sometimes high percentage of myeloid precursor cells within the wound were surprising. Possible explanations for this phenomenon are discussed.     

辛伐他汀对大鼠外周血单个核CD34+细胞动员作用的研究

 目的观察辛伐他汀动员大鼠外周血单个核CD34+细胞的作用.方法80只Wistar大鼠被随机分成辛伐他汀组和对照组.分别于给药1、2周后检测血脂水平,并用流式细胞仪行萤光激活细胞分类检测外周血单个核细胞中CD34+细胞率.结果(1)各组间血脂水平及外周血单个核细胞数无明显差别(P＞0.05).(2)无论是给药第1周后还是第2周后,辛伐他汀组外周血单个核细胞CD34+细胞率较对照组明显升高(P＜0.01).结论辛伐他汀可动员大鼠外周血单个核细胞中CD34+细胞.     

Hypoxia and etanidazole alter radiation-induced apoptosis in HL60 cells but not in MOLT-4 cells

PURPOSE: To examine how hypoxia influences ionizing irradiation-induced apoptosis in cultured mammalian cells and how a hypoxic cell radiosensitizer sensitizes apoptosis under hypoxic conditions. MATERIALS AND METHODS: Two cell lines derived from human lymphocytes, HL60 and MOLT-4, were exposed to 15 Gy X-rays under aerobic and hypoxic conditions. Etanidazole was used as a hypoxic cell radiosensitizer. The apoptotic morphological changes of nuclei and the induction of ladder-like DNA fragmentation were assessed by fluorescence microscopy and agarose gel electrophoresis, respectively. RESULTS: In HL60 cells, apototic cell death and the activation of caspases 8, 9 and 3 were less induced under the hypoxic conditions than under the aerobic ones. Treatment of hypoxic cells with etanidazole enhanced X-ray-induced apoptosis and caspase activation. However, in MOLT-4 cells, neither hypoxia nor etanidazole influenced X-ray-induced apoptosis and caspase activation. In both cell lines, the frequency of X-ray-induced DNA double-strand breaks (DSB) under hypoxia was significantly smaller than that in aerobic conditions. Treatment of hypoxic cells with etanidazole enhanced them. CONCLUSION: These results suggested that X-ray-induced apoptosis in HL60 cells was initiated by DNA DSB and the treatment of hypoxic cells with etanidazole sensitized them through the enhancement of DSB induction, whereas X-ray-induced apoptosis in MOLT-4 cells occurred through damage other than to DNA.