骨髓间充质干细胞向心肌分化的实验研究

目的:研究骨髓间充质干细胞(bone mesenchymal stem cells,BMSCs)分化为心肌样细胞的能力,用于心肌补片治疗心肌梗死的研究。方法:分离C57/BSL小鼠BMSCs,全培养差速贴壁法,经过贴壁培养至第3代,流式细胞仪鉴定细胞表面标志(CD34、CD45、CD73、CD90),经10μmol/L的5-氮杂胞苷诱导细胞,24 h后更换完全培养基培养,2 w后进行免疫荧光染色,荧光显微镜观察心肌钙蛋白T(cTnT)和连接素蛋白43(CX43)的表达。结果:流式鉴定结果显示CD34、CD45阴性,CD73强阳性,CD90弱阳性。免疫荧光染色显示,诱导后细胞高表达心肌细胞特异性蛋白cTnT,连接素蛋白CX43表达水平明显增加。结论:5-aza可以诱导BMSCs大量表达心肌特异性蛋白cTnT和细胞连接素蛋白(CX43),干细胞分化为心肌样细胞,为干细胞移植治疗小鼠心梗提供种子细胞。     

大鼠骨髓间充质干细胞的分离培养纯化与鉴定

目的:探讨骨髓间充质干细胞(BMSCs)体外获取及培养增殖的方法并鉴定。方法:用密度梯度离心法结合贴壁培养法分离、纯化培养大鼠BMSCs,测定生长曲线,流式细胞仪鉴定,免疫细胞化学检测。结果:密度梯度离心结合贴壁培养法能有效分离纯化大鼠BMSCs,P2、4、6代细胞生长曲线基本一致,增值能力强,呈均一成纤维样细胞,P3代以后细胞均一地表达细胞表面抗原CD44、CD90,不表达CD34,弱表达CD11b/c,细胞表达Connexin43。结论:本实验建立了一种体外稳定培养扩增大鼠BMSCs的方法,培养的细胞成分单一,适用于对BMSCs进一步的应用研究。     

大鼠骨髓间充质干细胞体外向心肌细胞诱导分化的机制

目的 研究大鼠骨髓间充质干细胞(BMSCs)体外向心肌细胞(CM)定向诱导分化的机制.方法 全骨髓贴壁法体外获取大鼠BMSC,流式细胞术检测CD44、CD45和CD105的表达率对其进行鉴定,以未加一抗只加二抗的BMSCs作为平行对照组.选用生长良好、纯度达到95％的P5代BMSCs,用5-氮杂胞苷(5-Aza)10 μmol/L进行诱导,对诱导后的细胞进行心肌特异性标志TroponineI的免疫组化检测.在诱导前及诱导2e以RT-PCR方法检测RhoA的表达变化.结果 体外分离纯化培养扩增出大鼠BMSCs,表达CD44、和CD105.经10 μmol/L 5-Aza诱导分化的BMSCs表达心肌特异性标记TroponineI;RT-PCR的结果显示,诱导后的BMSCs表达RhoA.结论 BMSCs可体外分离培养扩增,并具有向心肌细胞分化的潜能,5-Aza最佳诱导浓度为10 μmol/L.5-Aza体外可能通过RhoA途径在BMSCs分化为心肌细胞过程中起着重要调控作用.     

细胞接触诱导骨髓间充质干细胞获得窦房结细胞表型的初步研究

目的 通过建立体外骨髓间充质干细胞(BMSCs)与纯化培养的乳鼠窦房结细胞共培养体系,探讨窦房结微环境对BMSCs分化的诱导作用.方法 自新生乳鼠的心脏分离窦房结细胞,并差速贴壁纯化培养,免疫荧光检测超极化激活环核苷酸门控阳离子通道基因4(HCN4)和缝隙连接蛋白45(Cx45)的表达.自成年大鼠的骨髓分离BMSCs,传2代后,用脂质体介导pEGFP-N1转染标记BMSCs,再与纯化培养的窦房结细胞以1:5比例进行直接接触共培养,并用窦房结细胞条件培养液对转染后的BMSCs进行培养作为对照.1周后应用免疫荧光检测BMSCs的HCN4和Cx45表达.结果 接触共培养组中,可见部分表达绿色荧光蛋白的BMSCs同时表达HCN4和Cx45,而条件液培养组中未见HCN4和Cx45的表达.结论 直接接触共培养体系可诱导BMSCs初步分化为窦房结样细胞.     

小鼠骨髓基质干细胞的鉴定及体外诱导分化为肝细胞的可行性

目的:分离、鉴定小鼠骨髓基质干细胞(MSCs)并探讨在体外多种细胞因子的诱导下分化为肝细胞的可行性.方法:获取小鼠骨髓干细胞,进行体外贴壁培养、纯化,观察不同传代次数细胞形态特点.流式细胞法检测不同传代细胞的表面标志物CD45和CD90.分离后的MSCs再经含有HGF,FGF-4,EGF三种细胞因子的诱导体系继续培养21 d,分别以半定量逆转录聚合酶链反应(RT-PCR)和Western blot方法检测诱导后细胞的白蛋白(ALB)、细胞角化蛋白18(Cg18)、以及甲胎蛋白(AFP)在基因和蛋白水平的表达.结果:培养的骨髓干细胞随传代次数增多细胞形态趋向为长梭形.传代到第5代,基质干细胞的表面标志CD90阳性细胞从原代的25.42%增加到93.47%,造血干细胞的表面标志CD45表达阳性细胞从原代的86.49%降低到2.77%.通过RT-PCR可检测出诱导第7天细胞表达AFP mRNA,ALB mRNA及CK18 mRNA;通过Western blot可检测出诱导第21天的细胞表达ALB和CK18.结论:小鼠MSCs可以在体外被有效地分离纯化,可以被诱导为表达肝细胞表面标志的肝细胞样细胞.     

心肌组织裂解液诱导骨髓间充质干细胞向心肌样细胞分化的研究

目的探讨心肌组织裂解液定向诱导骨髓间充质干细胞(BMSCs)分化为心肌样细胞的可行性。方法体外分离、培养及鉴定大鼠BMSCs,实验分为3组:空白对照组、正常心肌组织裂解液诱导组和梗死心肌组织裂解液诱导组。分别对第3代BMSCs进行定向诱导,倒置相差显微镜观察诱导后细胞形态变化。诱导4周后,Western-blot检测心肌肌钙蛋白T(cTnT)、心肌连接蛋白43(Cx43)的表达。结果 P3代BMSCs CD34染色呈阴性,而CD105、CD106染色呈阳性。两个诱导组cTnT、Cx43蛋白表达量均高于空白对照组,且梗死心肌裂解液诱导组的蛋白表达量高于正常心肌组织裂解液诱导组,差异有统计学意义(P0.05)。结论正常心肌组织裂解液及梗死心肌组织裂解液均可诱导BMSCs分化为心肌样细胞,且梗死心肌组织裂解液组诱导分化效率更高。     

大鼠骨髓间充质干细胞的分离、培养及鉴定

目的体外分离、培养及鉴定大鼠骨髓间充质干细胞（MSC）。方法全骨髓贴壁法体外分离、培养3月龄SD大鼠MSC,利用差速贴壁原理纯化MSC,并通过形态学观察、细胞表面抗原标志物、多细胞系诱导分化对其进行鉴定。结果P3代不表达抗原CD34和CD45,表达抗原CD29和CD44,符合MSC表面标志物特征。P3代MSC定向诱导后经ALP染色、矿化结节染色、油红O染色、Ⅱ型胶原荧光染色后鉴定具有骨向分化、脂向分化及软骨分化能力。结论全骨髓贴壁法能够建立稳定的MSC体外分离培养体系。     

两种不同部位取材的大鼠骨髓基质细胞生物学特性比较

目的 分离、纯化培养不同部位取材的大鼠骨髓基质细胞(BMSCs),对其生物学特性进行检测和鉴定.方法 分别取大鼠长骨及尾椎骨中的骨髓组织,以本实验室骨专用培养基接种培养,经多次换液得到较纯的BM-SCs,在倒置显微镜下观察细胞形态.进行体外脂肪细胞定向诱导后,再进行油红O染色.应用流式细胞仪分别对两种细胞的表面抗原标志进行检测.结果 两种不同部位取材的培养细胞形态相似,脂肪细胞定向诱导后油红O染色均可见胞质内有红色脂肪颗粒,细胞表面抗原检测结果基本一致,分别显示为CD14阴性、CD45阴性、CD29阳性、CD90阳性.结论 两种不同部位取材的培养细胞表型特征均符合BMSCs.     

细胞传代对SD大鼠骨髓间充质干细胞衰老的影响

目的探究体外传代培养对SD大鼠骨髓间充质干细胞(BMSCs)衰老的影响。方法全骨髓贴壁法分离培养大鼠BMSCs,待细胞汇合率达80%～90%时,进行消化传代及纯化培养。对不同代数细胞,进行倒置显微镜下观察细胞形态学及生长特性,绘制1～7 d生长曲线,流式细胞仪检测细胞表面抗原标志物(CD29、CD45和CD90)和细胞周期,β-半乳糖苷酶染色并记录阳性细胞数,Western印迹法检测衰老相关蛋白P53和P21表达情况。结果 SD大鼠BMSCs的CD29、CD90高表达(95%),CD45低表达(5%),细胞周期中G0/G1期占87.37%;相较于P1～5代细胞,P7～9代细胞增殖能力明显下降,β-半乳糖苷酶染色阳性细胞明显增多;随着传代次数的增加,BMSCs的P53、P21表达增高。结论体外培养传代次数的增加可导致SD大鼠BMSCs衰老。     

一种改良大鼠骨髓间充质干细胞培养方法

目的建立大鼠骨髓间充质干细胞(BMSCs)的分离、改良培养、纯化方法,并进行细胞形态学观察、表面标志物鉴定及多向分化能力检测。方法通过改良全骨髓贴壁法对4周龄SD雄性大鼠脱颈处死,无菌条件下分离出骨髓进行原代培养、消化传代培养及纯化。对BMSCs进行形态学观察,收获第四代BMSCs进行流式细胞仪检测其细胞表面标记物CD90、CD29、CD34、CD45的表达率及向成脂方向诱导分化。结果 BMSCs的原代培养形态学观察可见骨髓细胞接种于培养皿后,细胞呈圆型,大小不一,悬浮于培养液中。24 h后部分细胞开始贴壁,呈圆形、梭形或多角形。通过换液去除未贴壁的杂质细胞,可见短梭形、星形细胞分散贴壁生长,四五天可见放射状排列的细胞集落,伸出长短不一、粗细不均的突起,梭形细胞为主,胞浆丰富,胞核大、核仁清晰。7~8 d细胞呈集落生长,融合80%~90%,呈漩涡状,同向排列,9~10 d细胞排列紧密,逐渐融合成片。传代培养可见消化传代后,传代细胞24 h完全贴壁生长。细胞形态均一,呈梭形生长,细胞生长旺盛。四至五天可传代1次。可稳定连续传代7代以上,细胞形态及生长速度未见明显变化。BMSCs表面标记物的表达通过流式细胞仪检测结果显示,培养的第4代大鼠BMSCs均一表达CD90,CD29,阳性率分别为96.9%,96.6%;而CD34,CD45,呈阴性,阳性率分别为0.395%,7.56%。BMSCs加入成脂诱导剂后18 d,诱导而成的脂肪细胞累积脂质,脂滴变大,合并呈串珠状,经油红O染色呈鲜红色。结论与传统全骨髓贴壁法相比,改良后的全骨髓贴壁法操作步骤简单,降低离心对细胞的损害,减少了污染机会,节省经费,且分离的BMSCs细胞活性高,可大量分离、纯化、扩增,所获细胞具有间充质干细胞的一般生物学特性,经诱导培养后具有多向分化潜能。可为组织器官缺损性疾病、恶性肿瘤等的治疗和组织工程提供充足的种子细胞来源,具有重要的现实意义。     

Glucose-responsive insulin-producing cells from stem cells

Recent success with immunosuppression following islet cell transplantation offers hope that a cell transplantation treatment for type 1 (juvenile) diabetes may be possible if sufficient quantities of safe and effective cells can be produced. For the treatment of type 1 diabetes, the two therapeutically essential functions are the ability to monitor blood glucose levels and the production of corresponding and sufficient levels of mature insulin to maintain glycemic control. Stem cells can replicate themselves and produce cells that take on more specialized functions. If a source of stem cells capable of yielding glucose-responsive insulin-producing (GRIP) cells can be identified, then transplantation-based treatment for type 1 diabetes may become widely available. Currently, stem cells from embryonic and adult sources are being investigated for their ability to proliferate and differentiate into cells with GRIP function. Human embryonic pluripotent stem cells, commonly referred to as embryonic stem (ES) cells and embryonic germ (EG) cells, have received significant attention owing to their broad capacity to differentiate and ability to proliferate well in culture. Their application to diabetes research is of particular promise, as it has been demonstrated that mouse ES cells are capable of producing cells able to normalize glucose levels of diabetic mice, and human ES cells can differentiate into cells capable of insulin production. Cells with GRIP function have also been derived from stem cells residing in adult organisms, here referred to as endogenous stem cell sources. Independent of source, stem cells capable of producing cells with GRIP function may provide a widely available cell transplantation treatment for type 1 diabetes.     

Insulin expressing cells from differentiated embryonic stem cells are not beta cells

Aim/hypothesis Embryonic stem (ES) cells have been proposed as a potential source of tissue for transplantation for the treatment of Type 1 diabetes. However, studies showing differentiation of beta cells from ES cells are controversial. The aim of this study was to characterise the insulin-expressing cells differentiated in vitro from ES cells and to assess their suitability for the treatment of diabetes.Methods ES cell-derived insulin-expressing cells were characterised by means of immunocytochemistry, RT-PCR and functional analyses. Activation of the Insulin I promoter during ES-cell differentiation was assessed in ES-cell lines transfected with a reporter gene. ES cell-derived cultures were transplanted into STZ-treated SCID-beige mice and blood glucose concentrations of diabetic mice were monitored for 3 weeks.Results Insulin-stained cells differentiated from ES cells were devoid of typical beta-cell granules, rarely showed immunoreactivity for C-peptide and were mostly apoptotic. The main producers of proinsulin/insulin in these cultures were neurons and neuronal precursors and a reporter gene under the control of the insulin I promoter was activated in cells with a neuronal phenotype. Insulin was released into the incubation medium but the secretion was not glucose-dependent. When the cultures were transplanted in diabetic mice they formed teratomas and did not reverse the hyperglycaemic state.Conclusions/Interpretation Our studies show that insulin-positive cells in vitro-differentiated from ES cells are not beta cells and suggest that alternative protocols, based on enrichment of ES cell-derived cultures with cells of the endodermal lineage, should be developed to generate true beta cells for the treatment of diabetes.Abbreviations ES Embryonic stem - LIF leukemia inhibitory factor - ITSF insulin-transferrin-selenite-fibronectin.Bleackley and Korbutt laboratories contributed equally to this paper     

DC与CIK或LAK联合对结肠癌细胞株SW480杀伤作用的研究

[目的]研究树突状细胞(DC)联合细胞因子诱导或未诱导的杀伤细胞(CIK)或淋巴因子激活的杀伤细胞(LAK)对结肠癌细胞株SW480的杀伤活性.提供DC联合CIK或LAK治疗结肠癌的实验依据.[方法]取人外周血分离出单个核细胞(PBMNC),诱导生成DC、CIK、LAK细胞;流式细胞仪检测DC经SW480肿瘤抗原冲击后的表型变化;以CIK+DC细胞、CIK细胞、LAK+DC细胞及LAK细胞作为效应细胞,SW480为靶细胞,以15∶1、30∶1、45∶1为效靶比,LDH释放法测定细胞杀伤试验活性;ELISA检测杀伤试验中干扰素γ(IFN-γ)、白细胞介素2(IL-2)、IL-12、IL-17的分泌水平.[结果]流式细胞仪检测DC经SW480肿瘤抗原冲击后,其表面分子HLA-DR、CD40、CD80和CD86表达分别平均为90.23％、73.68％、85.96％、57.55％,与未经肿瘤抗原冲击DC比较,DC成熟的表面标志分子表达明显增加(P＜0.01).相同效靶比下,CIK+DC细胞组对SW480的杀伤作用最强,明显高于其他细胞组(P＜0.01);CIK+ DC细胞组在效靶比为45∶1时,杀伤活性最强(P＜0.01);单独CIK细胞组的杀伤活性明显高于LAK+DC细胞组(P＜0.01);LAK+ DC细胞组的杀伤活性明显高于单独LAK细胞组(P＜0.01).效靶比为45∶1时,各杀伤试验细胞组上清液中IFN-γ、IL-2、IL-12、IL-17的分泌量,CIK+DC细胞组的IFN-γ、IL-12的分泌量显著高于其他细胞组(P＜0.05);LAK+DC、单独LAK细胞组IL-2的分泌量明显高于CIK+DC、单独CIK细胞组(P＜0.05);单独CIK细胞组IFN-γ的分泌量明显高于LAK+DC、单独LAK细胞组(P＜0.05).[结论]CIK+DC细胞组对SW480的杀伤活性明显强于单独CIK、LAK+ DC组、单独LAK细胞组.其机制可能是,SW480抗原致敏的DC分泌IFN-γ、IL-12等刺激、诱导CIK细胞的活化和增殖,明显增强CIK细胞杀伤SW480的活性.     

Dendritic cells: specialized antigen presenting cells

Renewing interest in cancer immunotherapy reflects the excellent results that have been obtained in animal models and the promising results in early clinical trails with dendritic cell (DC) based approaches. The central role that DCs play in the initiation of an immune response raises the possibility of using them to trigger specific anti-tumor immunity. In addition, deeper knowledge of DC biology will allow better understanding of the mechanism(s) underlying allergic and autoimmune diseases as well as tolerance phenomena. These crucial issues were critically reviewed during a workshop organized by the Italian Society for Experimental Hematology in Florence, Italy, on March 18th, 1999. The chairmen have prepared this report for the readers of Haematologica.     

树突状细胞联合细胞因子诱导的杀伤细胞对胃癌细胞杀伤作用

目的探讨树突状细胞联合细胞因子诱导的杀伤细胞对胃癌细胞的杀伤作用。方法采用胃癌患者自身血液中单个核细胞(peripheral blood mononuclear cells,PBMC),经体外诱导分别扩增出DC和CIK细胞,二者共同培养后,利用MTT法检测DC细胞联合CIK细胞体外杀伤人胃癌细胞株(MNK-45、MNK-28、SG-7901)的活性。结果DC与CIK细胞共培养后得到的细胞群高表达CD3 CD56 ,平均值达到(56.74±7.63)%。通过彼此相互作用诱导出的细胞群体对胃癌细胞株MNK-45、MNK-28、SG-7901有杀伤作用,且杀伤活性随着效靶比的增加而增强。结论DC与CIK细胞共培养后有很强的增殖能力,对胃癌细胞具有杀伤活性,且其杀伤作用与胃癌细胞类型无相关性。