成人骨髓间质干细胞定向诱导为脂肪细胞的研究

目的:体外定向诱导成人骨髓间质干细胞(MSC)分化为脂肪细胞。方法:采用Ficoll-Paque淋巴细胞分离液(1.077×10³g/L)离心分离成人MSC,体外扩增,流式细胞仪检测MSC表面抗原表达,地塞米松、IBMX、胰岛素、indomethacin定向诱导MSC分化为脂肪细胞。油红O检测中性脂肪,光镜下细胞计数。结果:成人骨髓间质干细胞在体外扩增5代可获得1×10⁸个细胞。流式细胞仪检测结果显示CD29、CD44、CD90、CD105、CD166表达阳性,CD14、CD34、CD45、CD11a为阴性。诱导48h后,细胞内有脂滴出现,随着时间延长,脂滴逐渐增加并融合为脂泡。细胞由梭形转变为圆形或多角性。细胞计数结果显示85%以上细胞转变为脂肪细胞。结论:成人骨髓间质干细胞在体外可以分化为脂肪细胞。     

大鼠骨髓间充质干细胞分离培养及向脂肪细胞分化的实验研究

目的探讨体外大鼠骨髓间充质干细胞(MSCs)的分离培养及向脂肪细胞的分化潜能。方法从大鼠骨髓中获得间充质干细胞,体外培养传代。通过地塞米松、胰岛素等诱导MSCs向脂肪细胞分化,采用苏丹Ⅳ染色鉴定。结果诱导培养4d后,细胞胞浆内开始出现细小脂滴,12 d后在可观察到大量细胞由长梭形变为圆形或多边形,胞浆内形成高折光性的脂滴,苏丹Ⅳ脂肪染色后显示克隆中心的细胞胞浆内大量的颗粒状红色脂滴形成。细胞爬片显示约有60%骨髓间充质干细胞分化为脂肪细胞。结论大鼠骨髓间充质干细胞能进行体外分离培养并能诱导分化为脂肪细胞。     

促进胚胎干细胞来源造血干/祖细胞移植后细胞免疫功能恢复

目的:体外诱导胚胎干细胞分化为造血干/祖细胞过程中, 增加成熟T淋巴细胞的含量, 以促进其重建致死量照射小鼠的造血功能后免疫功能的早期重建。方法:胚胎干细胞在含甲基纤维素的培养基中自由分化形成胚胎体, 分化第6d添加造血生长因子, 同时添加胸腺肽, 流式细胞仪检测分化细胞中CD₃₄⁺的造血干/祖细胞和CD⁺₃的成熟T淋巴细胞含量, 最后将分化细胞注射入致死量照射小鼠体内, 观察60d, 以移植物抗宿主病(GVHD)发病率作为T淋巴细胞免疫功能的指标, 用PCR检测Sry反映移植细胞在宿主体内的存活。结果:分化第13d, 未加胸腺肽, CD⁺₃的成熟T淋巴细胞含量仅10.52%, 重建造血后无GVHD发生;添加胸腺肽, CD⁺₃的成熟T淋巴细胞含量升高达22.93%, 重建造血后GVHD发病率100%。结论:胚胎干细胞体外分化为造血干/祖细胞过程中, 添加胸腺肽, 能增加CD⁺₃的成熟T淋巴细胞含量, 体内重建造血后细胞免疫功能恢复较快。     

胚胎小鼠肝脏Sca-1+细胞横向分化的研究

目的:研究和探索胚胎小鼠肝脏细胞的横向分化潜能。方法:将2×10³ C57BL/6j雄性胚胎小鼠的肝脏Sca-1⁺细胞从尾静脉注射到受致死性γ射线(10 Gy, ⁶⁰Co)全身照射的同种成年雌性小鼠体内;于移植后2个月, 用荧光原位杂交和免疫组织化学技术, 检测雄性胚胎小鼠肝脏Sca-1⁺细胞在雌性受体小鼠肾脏和脑组织内的分化情况。结果:在雌性受体小鼠的肾脏和脑组织内, 分别检测到Y染色体阳性的供体来源的肾小管上皮组织细胞样和神经组织细胞样的细胞, 其细胞表型分别为RCA⁺/CD^-₄₅F^-_4/80和NueN⁺/CD^-₄₅F^-_4/80。结论:胚胎小鼠肝脏Sca-1⁺细胞具有向肾脏和脑组织细胞横向分化的能力。     

人卵黄囊间质干细胞的分离纯化及诱导成脂的实验研究

目的:分离纯化及体外定向诱导人卵黄囊间质干细胞(YS-MSC)分化为脂肪细胞。方法:显微分离人卵黄囊, 经酶消化得到卵黄囊细胞, 卵黄囊细胞经贴壁培养、传代纯化得到人YS-MSC, 流式细胞仪检测YS-MSC表面抗原表达, 钙钴法测定碱性磷酸酶(AKP)活性;地塞米松、消炎痛、胰岛素定向诱导YS-MSC分化为脂肪细胞。油红O检测中性脂肪。结果:人卵黄囊间质干细胞易于分离、纯化, 体外培养增殖潜能大。卵黄囊间质干细胞CD29、CD44、CD166及CD105表达阳性, CD34、CD45和CD86为阴性;AKP弱阳性。卵黄囊间质干细胞经成脂诱导转化为大小不等的园形或椭圆形细胞, 可见胞浆内有少量微小脂滴形成, 随时间延长, 胞浆中脂滴相互融合, 胞核被挤于细胞的一侧, 经油红O染色脂滴染橘红色, 符合脂肪细胞的生物学特征。结论:人卵黄囊间质干细胞与成体间质干细胞表型一致, 在体外可以分化为脂肪细胞。     

补肾活血中药对免疫介导再障小鼠骨髓CD45+细胞的影响

目的:观察补肾活血中药对免疫介导再障小鼠CD₄₅⁺细胞的影响。方法:建立免疫介导再障小鼠模型,随机分组胃饲生理盐水、高剂量中药、低剂量中药、环孢素A(CsA),并设正常对照,第10d分别称体重、计算外周血细胞和骨髓有核细胞数、采用流式细胞技术测定骨髓CD₄₅⁺细胞。结果:中药组小鼠体重、外周血细胞、骨髓有核细胞数、骨髓CD₄₅⁺细胞显著高于空白模型组和CsA组,而接近正常对照组。结论:补肾活血中药对免疫介导再障小鼠的骨髓造血细胞有保护作用。     

α1胸腺肽对胸腺细胞发育和成熟的影响

目的:探讨α₁胸腺肽对胸腺细胞发育的影响。方法:测定CD4⁺CD8⁺胸腺细胞群的比例及 5-FU和胸腺肽处理组在CD4^-CD8^-胸腺细胞群上Hh信号的Smo分子(增生反应的潜在阴性调节者)的表达效果来估价胸腺肽对胸腺细胞成熟和发育的影响。结果:发现α₁胸腺肽在30μg/kg的低剂量下显示活性。流式细胞仪分析根据CD4^-CD8^-胸腺细胞上Hh信号的Smo分子的表达确定α₁胸腺肽在此剂量加快了胸腺细胞的成熟。结论:α₁胸腺肽能加快CD4^-CD8^-胸腺细胞向CD4⁺ CD8⁺阶段的发展。     

小鼠卵黄囊间充质干细胞的培养及鉴别

目的 研究小鼠卵黄囊间充质干细胞(YS-MSCs)的分离、培养和鉴定.方法 显微分离妊娠10d的小鼠胚胎卵黄囊,经0.1%的Ⅰ型胶原酶消化1h得到卵黄囊细胞,取贴壁细胞培养,并于接近汇合时进行传代培养,透射电镜下观察YS-MSCs的超微结构;流式细胞仪检测YS-MSCs表面标志;钙钴法测定YS-MSCs碱性磷酸酶(AKP)活性;细胞组织化学检测YS-MSCs化学变化;地塞米松、胰岛素定向诱导YS-MSCs分化为脂肪细胞,油红0检测中性脂肪.结果 体外可获得YS-MSCs,细胞大多数呈梭形;透射电镜下YS-MSCs表面有微绒毛,胞浆中有丰富的线粒体、粗面内质网、高尔基复合体;核大,形态不规则;流式细胞术分析YS-MSCs免疫表型显示,原代和第1代YS-MSCs均为CD44、CD105阳性,CD34也有少量表达;细胞化学YS-MSCs PAS-过碘酸雪夫染色阳性,苏丹黑-B (S8)及碱性磷酸酶(AKP)染色阴性;YS-MSGs经成脂诱导后,胞浆中有脂滴形成,经油红0染色脂滴呈鲜红色.结论 小鼠YS-MSCs的生物学特性与成体间充质干细胞相似,且更为原始,提示其可作为组织工程的种子细胞来源.     

人脂肪间充质干细胞成功诱导分化为脂肪细胞

目的分离培养人脂肪间充质干细胞(h ADSCs),探讨h ADSCs生长特性及分化为脂肪细胞的能力。方法采用Ⅰ型胶原酶消化和贴壁筛选联合培养方法,从人腹部吸脂术所抽取的脂肪组织中分离培养间充质干细胞,传代,绘制其生长曲线,免疫细胞化学染色检测细胞表面标志物以鉴定所分离细胞;利用三联诱导法诱导人脂肪间充质干细胞向脂肪细胞分化,并进行油红O染色鉴定,显微镜下观察。结果原代人脂肪源间充质干细胞贴壁生长,为形态相对均一的梭形细胞,呈平行排列生长,生长曲线呈"s"型分布,间充质干细胞相关标志物CD44、CD49d高表达,而CD34、CD106则呈阴性。三联诱导法成功诱导人脂肪源间充质干细胞向脂肪细胞分化,诱导7d后镜下可见脂滴的出现,12d后最为显著,油红O染色脂滴着红色。结论 h ADSCs经过体外扩增及成脂诱导成功分化为脂肪细胞,可成为组织工程理想种子细胞。     

镁对哮喘患者外周血CD4+ CD25+调节性T细胞凋亡及Foxp3表达的影响

目的:观察镁对分离培养的健康人和哮喘患者外周血CD4⁺CD25⁺调节性T细胞凋亡及叉头框蛋白3(Foxp3)表达的影响。方法:经磁珠分离法分离出健康人和哮喘患者外周血CD4⁺CD25⁺T细胞,分镁剂干预组(10 mmol/L)及空白组培养72 h后,用流式细胞仪检测CD4⁺CD25⁺T细胞的凋亡率及Foxp3表达情况。结果:(1)健康人外周血CD4⁺CD25⁺T细胞的纯度为77.4％~92.3%,哮喘患者CD4⁺CD25⁺T细胞的纯度为75.2％~93.8％。(2)CD4⁺CD25⁺T细胞占外周血CD4⁺T细胞的比例在健康组为4.12%~7.98%,在哮喘组为4.51%~8.68%,两者没有显著差异(P＞0.05)。(3)镁(10mmol/L)可以诱导健康组及哮喘组外周血CD4⁺CD25⁺T细胞凋亡率增加(P＜0.05),但对Foxp3的表达无影响(P＞0.05)。结论:镁促进CD4⁺CD25⁺T调节细胞凋亡增加可能为其治疗支气管哮喘的作用机制之一。     

Mesenchymal stem cells can be differentiated into endothelial cells in vitro

Human bone marrow-derived mesenchymal stem cells (MSCs) have the potential to differentiate into mesenchymal tissues like osteocytes, chondrocytes, and adipocytes in vivo and in vitro. The aim of this study was to investigate the in vitro differentiation of MSCs into cells of the endothelial lineage. MSCs were generated out of mononuclear bone marrow cells from healthy donors separated by density gradient centrifugation. Cells were characterized by flow cytometry using a panel of monoclonal antibodies and were tested for their potential to differentiate along different mesenchymal lineages. Isolated MSCs were positive for the markers CD105, CD73, CD166, CD90, and CD44 and negative for typical hematopoietic and endothelial markers. They were able to differentiate into adipocytes and osteocytes after cultivation in respective media. Differentiation into endothelial-like cells was induced by cultivation of confluent cells in the presence of 2% fetal calf serum and 50 ng/ml vascular endothelial growth factor. Laser scanning cytometry analysis of the confluent cells in situ showed a strong increase of expression of endothelial-specific markers like KDR and FLT-1, and immunofluorescence analysis showed typical expression of the von Willebrand factor. The functional behavior of the differentiated cells was tested with an in vitro angiogenesis test kit where cells formed characteristic capillary-like structures. We could show the differentiation of expanded adult human MSCs into cells with phenotypic and functional features of endothelial cells. These predifferentiated cells provide new options for engineering of artificial tissues based on autologous MSCs and vascularized engineered tissues.     

Expansion of mesenchymal stem cells from human pancreatic ductal epithelium

Fibroblast-like cells emerging from cultured human pancreatic endocrine and exocrine tissue have been reported. Although a thorough phenotypic characterization of these cells has not yet been carried out, these cells have been hypothesized to be contaminating fibroblasts, mesenchyme and/or possibly beta-cell progenitors. In this study, we expanded fibroblast-like cells from adult human exocrine pancreas following islet isolation and characterized these cells as mesenchymal stem cells (MSCs) based on their cell surface antigen expression and ability to differentiate into mesoderm. Analysis by flow cytometry demonstrated that pancreatic MSCs express cell surface antigens used to define MSCs isolated from bone marrow such as CD13, CD29, CD44, CD49b, CD54, CD90 and CD105. In addition, utilizing protocols used to differentiate MSCs isolated from other somatic tissues, we successfully differentiated pancreatic MSCs into: (1) osteocytes that stained positive for alkaline phosphatase, collagen, mineralization (calcification) and expressed osteocalcin, (2) adipocytes that contained lipid inclusions and expressed fatty acid binding protein 4 and (3) chondrocytes that expressed aggrecan. We also demonstrated that pancreatic MSCs are multipotent and capable of deriving cells of endodermal origin. Pancreatic MSCs were differentiated into hepatocytes that stained positive for human serum albumin and expressed endoderm and liver-specific genes such as GATA 4 and tyrosine aminotransferase. In addition, preliminary protocols used to differentiate these cells into insulin-producing cells resulted in the expression of genes necessary for islet and beta-cell development such as Pax4 and neurogenin 3. Therefore, multipotent MSCs residing within the adult exocrine pancreas could represent a progenitor cell, which when further manipulated could result in the production of functional islet beta-cells.     

Differentiation of human embryonic stem cells into bipotent mesenchymal stem cells

Mesenchymal stem cells (MSCs) are multipotent progenitors that can be found in many connective tissues, including fat, bone, cartilage, and muscle. We report here a method to reproducibly differentiate human embryonic stem cells (hESCs) into MSCs that does not require the use of any feeder layer. The cells obtained with this procedure are morphologically similar to bone marrow MSCs, are contact-inhibited, can be grown in culture for about 20 to 25 passages, have an immunophenotype similar to bone marrow MSCs (negative for CD34 and CD45 and positive for CD13, CD44, CD71, CD73, CD105, CD166, human leukocyte antigen [HLA]-ABC, and stage-specific embryonic antigen [SSEA]-4), can differentiate into osteocytes and adipocytes, and can be used as feeder cells to support the growth of undifferentiated hESCs. The ability to produce MSCs from hESCs should prove useful to produce large amounts of genetically identical and genetically modifiable MSCs that can be used to study the biology of MSCs and for therapeutic applications.     

采用组织贴壁法从整根脐带分离培养间充质干细胞及其生物学特性的研究

 为了建立从整根脐带中分离培养间充质干细胞(UC-MSCs)的技术,并对其生物学特性进行研究。采用组织贴壁法分离UC-MSCs, 并通过传代进行纯化和扩增培养, 绘制生长曲线：用流式细胞仪检测UC-MSCs表面抗原及细胞周期; 在特定诱导体系中,检测UC-MSCs向脂肪、成骨及软骨分化的能力;采用RT-PCR检测多能干细胞标志多能干细胞标志Oct4, Sox-2, Nanog mRNA水平。结果表明,　成功建立了UC-MSCs分离培养的方法;流式细胞仪检测结果显示, 贴壁细胞均表达CD73 、CD90 、CD105, 不表达造血细胞表型CD34、CD45 和HLA-DR ;细胞倍增时间为(24.04±0.49)h , 细胞周期分析表明,G0～G1 期和S+ G2 + M 期所占比例分别为81.56 %和18.44%;UC-MSCs能够向脂肪、成骨和软骨分化;表达Oct4, Sox-2, Nanog基因。结论：组织贴壁法是一种较好的分离培养UC-MSCs的方法,培养的细胞为具有增殖能力强和更原始间充质干细胞,为建立间充质干细胞库和临床应用提供了理论依据。     

Isolation of human multipotent mesenchymal stem cells from second-trimester amniotic fluid using a novel two-stage culture protocol

BACKGROUND: The aim of this study was to isolate mesenchymal stem cells (MSCs) from amniotic fluid obtained by second-trimester amniocentesis. METHODS: A novel two-stage culture protocol for culturing MSCs was developed. Flow cytometry, RT-PCR and immunocytochemistry were used to analyse the phenotypic characteristics of the cultured MSCs. Von Kossa, Oil Red O and TuJ-1 stainings were used to assess the differentiation potentials of MSCs. RESULTS: Amniotic fluid-derived MSCs (AFMSCs) were successfully isolated, cultured and enriched without interfering with the routine process of fetal karyotyping. Flow cytometry analyses showed that they were positive for SH2, SH3, SH4, CD29, CD44 and HLA-ABC (MHC class I), low positive for CD90 and CD105, but negative for CD10, CD11b, CD14, CD34, CD117, HLA-DR, DP, DQ (MHC class II) and EMA. Importantly, a subpopulation of Oct-4-positive cells was detectable in our cultured AFMSCs. Under specific culture conditions, AFMSCs could be induced to differentiate into adipocytes, osteocytes and neuronal cells. CONCLUSIONS: We demonstrate that human multipotent MSCs are present in second-trimester amniotic fluid. Considering the great potential of cellular therapy using fetal stem cells and the feasibility of intrauterine fetal tissue engineering, amniotic fluid may provide an excellent alternative source for investigation of human MSCs.     

全骨髓直接贴壁分离人骨髓间充质干细胞的生物学特性****☆

背景：体外分离培养骨髓间充质干细胞成为实验研究和临床应用的关键环节。 目的：采用全骨髓培养法分离人骨髓间充质干细胞,建立一种简单、有效的分离培养骨髓间充质干细胞的方法。 方法：通过全骨髓培养法分离培养人骨髓间充质干细胞,并通过传代进行纯化和扩增培养。分别在特定诱导体系中诱导人骨髓间充质干细胞向脂肪、成骨及软骨细胞分化。 结果与结论：采用全骨髓培养分离法能获得90%以上纯度的骨髓间充质干细胞;流式细胞仪检测结果显示,贴壁细胞均表达CD73、CD90、CD105,不表达造血细胞表型CD34、CD45和HLA-DR;细胞倍增时间为(24.04±0.49) h;细胞周期分析表明：G0~G1期和S+G2+M期所占比例分别为71.63%和28.37%;诱导分化结果显示,人骨髓间充质干细胞能够向脂肪、骨和软骨细胞分化。说明全骨髓分离培养法是一种较好的分离人骨髓间充质干细胞的方法。     

Derivation of clinically compliant MSCs from CD105+, CD24- differentiated human ESCs

Adult tissue-derived mesenchymal stem cells (MSCs) have demonstrated therapeutic efficacy in treating diseases or repairing damaged tissues through mechanisms thought to be mediated by either cell replacement or secretion of paracrine factors. Characterized, self-renewing human ESCs could potentially be an invariable source of consistently uniform MSCs for therapeutic applications. Here we describe a clinically relevant and reproducible manner of generating identical batches of hESC-derived MSC (hESC-MSC) cultures that circumvents exposure to virus, mouse cells, or serum. Trypsinization and propagation of HuES9 or H1 hESCs in feeder- and serum-free selection media generated three polyclonal, karyotypically stable, and phenotypically MSC-like cultures that do not express pluripotency-associated markers but displayed MSC-like surface antigens and gene expression profile. They differentiate into adipocytes, osteocytes, and chondrocytes in vitro. Gene expression and fluorescence-activated cell sorter analysis identified CD105 and CD24 as highly expressed antigens on hESC-MSCs and hESCs, respectively. CD105+, CD24- monoclonal isolates have a typical MSC gene expression profiles and were identical to each other with a highly correlated gene expression profile (r(2) > .90). We have developed a protocol to reproducibly generate clinically compliant and identical hESC-MSC cultures.