脐血浆分离培养人脐带间充质干细胞

目的:利用脐带血血浆分离、培养人脐带间充质干细胞(HUCMSCs).方法:将脐血浆经盐析、透析等处理后,按10％体积成分分离、培养扩增HUCMSCs,观察细胞的形态,流式细胞仪检测细胞表面标志,MTT法检测细胞生长曲线、增殖能力,ELISA检测培养液中碱性成纤维细胞生长因子(bFGF)、noggin的分泌浓度.结果:利用含10％脐带血血浆的培养液能分离、扩增HUCMSCs,分离纯化的HUCMSCs成梭形、增殖能力强、具有分化为成骨细胞、脂肪细胞及神经干细胞的能力,高表达CD29、CD44,低表达或不表达CD34、CD45及HLA-DR.而且在含10％脐带血血浆的培养液中生长的HUCMSCs还能分泌人胚胎干细胞(hESC)生长所需的的bFGF及noggin.结论:脐带血血浆经简单处理后能分离培养HUCMSCs,而且其分泌的细胞因子更适合hESC培养需要.     

人胎盘血间质干细胞分离培养

目的：分离培养人胎盘血间质干细胞（hMSC），为hMSC探寻新来源。方法：采用羟乙基淀粉（HES）方法分离、富集胎盘血有核细胞；DMEM培养液体外培养、纯化、扩增hMSC；流式细胞仪检测细胞表面标记；地塞米松、IBMX、胰岛素和吲哚美辛定向诱导hMSC样细胞向脂肪细胞分化。结果：胎盘血来源有核细胞,在DMEM体外培养条件下，生长出具有塑料粘附特性的梭形细胞，阳性获得率29.17%（7/24），该细胞传代培养达6个月以上；流式细胞仪检测结果显示CD29、CD44、CD59、CD90、CD105、CD166表达阳性，CD14、CD34、CD45、CD80、CD86表达阴性；加入脂肪细胞诱导剂，细胞在形态上向脂肪细胞转化，胞内出现脂滴、脂泡，油红O阳性。结论：人胎盘血可以分离培养出hMSC，是hMSC的重要来源。     

脐血CD34+造血干/祖细胞基因表达图谱的研究

目的：通过脐血CD34^＋造血干／祖细胞的基因表达分析，理解造血干／祖细胞生物学特性。方法：利用MiniMACS免疫磁珠法从脐血细胞中分离CD34^＋造血干／祖细胞，提取总RNA，用SMART-PCR技术从微量RNA中扩增产生足够量的cDNA用于高密度点阵膜分析检测CD34^＋造血干／祖细胞表达的基因。结果：在所检测的588个基因中，发现63个基因具有显著的表达水平，其中18个基因强表达。这些基因主要涉及造血干细胞增殖、分化、应激响应、凋亡、转录调节以及细胞周期等。结论：对理解脐血干／祖细胞生物学性质以及指导造血干细胞体外培养提供了分子生物学基础。     

脐血单个核细胞与骨髓间充质干细胞滋养层的共培养

背景：骨髓间充质干细胞具有维持骨髓正常造血功能,在造血调控中发挥重要的作用。 目的：观察骨髓间充质干细胞的生物学性状和多向分化能力,并检测其在体外支持造血的能力。 方法：利用密度梯度培养法分离骨髓单个核细胞进行培养,流式细胞仪检测骨髓间充质干细胞表型;接种脐血单个核细胞于骨髓间充质干细胞滋养层培养板上共培养,观察粒-单系祖细胞集落变化。 结果与结论：骨髓间充质干细胞呈典型的成纤维样细胞形态,强表达CD44,CD29,不表达CD34和CD106。可促进脐血单个核细胞扩增并形成造血祖细胞集落。提示骨髓间充质干细具有造血支持作用。     

人脐血来源MSCs的主要生物学特性的研究

目的：探讨人脐血间充质干细胞（MSCs）分离、纯化、扩增、表面标志、免疫表型及其造血生长因子（HGFs）分泌等生物学特性方法：(1) Ficoll法分离、纯化人脐血、成人骨髓和胎儿骨髓MSCs，动态观察不同来源MSCs的生长状况。(2) 流式细胞仪检测脐血和骨髓MSCs表面CD34、CD45、CD14、CD29、CD44、CD105、CD166、CD80、CD86、CD40和CD40L的表达。(3) ELISA法检测脐血和骨髓MSCs培养上清中SCF、TPO、FLT-3L和IL-6的分泌水平。结果：(1) 所有骨髓标本中均可分离纯化出MSCs，而15份脐血中仅4份分离纯化出MSCs，脐血MSCs和骨髓MSCs的细胞形态无明显差异,脐血MSCs原代培养所需要的单个核细胞（MNC）量为骨髓MSCs的3倍，且其原代培养的增殖速度较慢，但脐血MSCs传代培养的增殖速度和骨髓相似。(2) 脐血MSCs和骨髓MSCs表面标志无差异，均不表达造血细胞表面标志以及与免疫识别有关的表面抗原。(3) 脐血和骨髓MSCs分泌SCF、TPO、FLT-3L和IL-6的水平相似。结论： (1)脐血和骨髓同样可以分离、纯化MSCs，但脐血中MSCs的含量少，且大部分脐血中不含MSCs。(2)纯化的脐血MSCs扩增能力、表面标志、免疫学表型及HGFs分泌水平和骨髓MSCs相似。     

High efficiency electroporation of human umbilical cord blood CD34+ hematopoietic precursor cells.

Human umbilical cord blood provides an alternative source of hematopoietic cells for purposes of transplantation or ex vivo genetic modification. The objective of this study was to evaluate electroporation as a means to introduce foreign genes into human cord blood CD34+ cells and evaluate gene expression in CD34+/CD38(dim) and committed myeloid progenitors (CD33+, CD11b+). CD34+ cells were cultured in X-VIVO 10 supplemented with thrombopoietin, stem cell factor, and Flt-3 ligand. Electroporation efficiency and cell viability measured by flow cytometry using enhanced green fluorescent protein (EGFP) as a reporter indicated 31% +/- 2% EGFP+ /CD34+ efficiency and 77% +/- 3% viability as determined 48 hours post-electroporation. The addition of allogeneic cord blood plasma increased the efficiency to 44% +/- 5% with no effect on viability. Of the total CD34+ cells 48 hours post-electroporation, 20% were CD38(dim)/EGFP+. CD34+ cells exposed to interleukin-3, GM-CSF and G-CSF for an additional 11 days differentiated into CD33+ and CD11b+ cells, and 9% +/- 3% and 8% +/- 7% were expressing the reporter gene, respectively. We show that electroporation can be used to introduce foreign genes into early hematopoietic stem cells (CD34+/CD38(dim)), and that the introduced gene is functionally expressed following expansion into committed myeloid progenitors (CD33+, CD11b+) in response to corresponding cytokines. Further investigation is needed to determine the transgene expression in functional terminal cells derived from the genetically modified CD34+ cells, such as T cells and dendritic cells.     

Generation of natural killer cells from serum-free, expanded human umbilical cord blood CD34+ cells

Natural killer (NK) cells are important effectors of the innate immune system, which exhibits cytolytic activity against infectious agents and tumor cells. NK cells are derived from CD34(+) hematopoietic stem cells (HSCs). Human umbilical cord blood (UCB) has been recognized as a rich source of HSCs. Previously, we have reported an optimized serum-free medium for ex vivo expansion of CD34(+) cells from UCB. In this study, the serum-free, expanded CD34(+) cells were tested to differentiate into NK cells and their induction kinetics. After 5 weeks of induction, the induced NK cells were characterized by analysis of surface antigens, IFN-gamma secretion, and cytotoxicity against K562 cells. The results indicated that NK cells derived from the serum-free, expanded CD34(+) cells exhibited both characteristics and functions of NK cells. Furthermore, the serum-free, expanded CD34(+) cells showed a significantly higher NK cell differentiation potential than freshly isolated CD34(+) cells. NK cells induced from serum-free, expanded CD34(+) cells showed a higher concentration of IFN-gamma secretion and ability of cytotoxicity than those from freshly isolated CD34(+) cells. Therefore, ex vivo-expanded CD34(+) cells in optimized serum-free medium could differentiate into NK cells and provided a promising cell source for immunotherapeutic approaches.     

脐带血间充质干细胞的研究进展

脐带血中存在着丰富的造血干细胞,在移植方面发挥重要作用,在脐血中是否还存在间充质干细胞却有争议,有的学者认为其中有间充质干细胞,且与骨髓间充质干细胞(mesenchymalstemcells,MSC)的形态、表面标志及分化潜能非常相似,有的学者认为含量较低,难以传代培养扩增,总结了近5年来国内外关于脐血间充质干细胞的研究情况,为脐血的充分利用提供更多的资料。     

人脐带间充质干细胞诱导分化为神经元样细胞

目的 探讨人脐带间充质干细胞(hUC-MSCs)体外诱导向神经细胞分化的潜能.方法 用生长因子bFGF和EGF联合全反式维甲酸(RA)、中药单体熊果酸、新生大鼠皮层神经元原代无血清培养的上清液3种方法,诱导hUC-MSCs向神经细胞分化,观察形态改变,用免疫细胞化学法检测神经细胞相关的标记物Nestin、Musashi-1和Tubulin、GFAP、O4.结果 hUC-MSCs经细胞因子、2mg*L的熊果酸诱导后,细胞由成纤维状逐渐变成双极、多极或锥形,胞体缩小;有些细胞伸出突起,随时间推移逐渐伸长,有些可形成次级突起,相互连结形成网状.另有一些胞体呈球形,突起较短.新生大鼠皮层神经元原代无血清培养的上清液诱导hUC-MSCs先形成Nestin和Musashi-1阳性的神经球,再经历上述形态变化,分化形成神经元样细胞.hUC-MSCs经诱导14 d后,有少量细胞表达Tubulin、GFAP、O4.结论 hUC-MSCs在体外特定条件下,可诱导分化为神经细胞,作为神经系统疾病细胞移植治疗的备选来源.     

影响脐血间充质干细胞分离培养的关键环节

背景：脐血中存在间充质干细胞,目前国内外尚未见到对脐血间充质干细胞体外分离、培养及扩增较统一且有效的方法。 目的：探讨影响人脐血间充质干细胞成功分离培养的相关因素。 方法：分别从不同胎龄(≥40周,37周和≤32周),脐血中单个核细胞数量(≥2.5× 10⁹ L^-1,< 2.5×10⁹ L^-1), 不同细胞接种浓度(1×10⁷,1×10⁹,1×10¹¹ L^-1),不同体积分数胎牛血清(5%,10%,15%,20%)以及培养瓶是否被胎牛血清包被等方面对人脐血间充质干细胞分离培养成功率进行比较。 结果与结论：脐血间充质干细胞的分离培养成功率为58.3%,且随胎龄的增高而培养成功率降低(P < 0.01);脐血中单个核细胞浓度≥2.5×10⁹ L^-1组培养成功率高于< 2.5×10⁹ L^-1组(P < 0.01);相同容量脐血中单个核细胞数量与胎龄呈负相关(r = -0.95,P < 0.01);1×10¹¹ L^-1组原代及传代培养的间充质干细胞生长及扩增情况高于1×10⁷,1×10⁹ L^-1;体积分数5%FBS组间充质干细胞贴壁速度较其他3组略慢,但细胞纯度较高,且细胞传代速度与其他3组无明显差别;胎牛血清包被组脐血间充质干细胞原代和传代后的纯度及扩增能力均高于未包被组。提示脐血间充质干细胞分离培养成功率受多种因素的影响：通过选择较低胎龄的胎儿,采集足够量的脐血,以较高的细胞密度接种,培养基中添加较低浓度的胎牛血清,并将培养瓶预先用胎牛血清进行包被,能在体外建立稳定的脐血间充质干细胞培养体系。     

Hepatogenic potential of human bone marrow and umbilical cord blood mesenchymal stem cells

Conditions of human BM and umbilical cord blood MSC in vitro differentiation in the hepatogenic direction were studied. Changes in cell morphology, phenotype, acquisition of the capacity to produce albumin and accumulate glycogen, express cytokeratin, alkaline phosphatase, and albumin mRNA indicated that BM and umbilical cord blood MSC differentiated in vitro into immature hepatocyte-like cells.     

Osmotic selection of human mesenchymal stem/progenitor cells from umbilical cord blood

The isolation of undifferentiated adult stem/progenitor cells remains a challenging task primarily due to the rare quantity of these cells in biological samples and the lack of unique markers. Herein, we report a relatively straightforward method for isolation of human mesenchymal stem cells (MSCs) based on their unusual resistance to osmotic lysis, which we term "osmotic selection" (OS). MSCs can remarkably withstand significant exposure to hypotonic conditions (> 30 min) with only a reversible impairment in cell proliferation and with no loss of stem cell potential after exposure. Comparison of MSCs to other circulating nonhematopoietic cells revealed a time regime, by which purification of these cells would be attainable without considerable cell loss. OS showed a 50-fold enrichment of fibroblast colony-forming units from umbilical cord blood samples when compared to commonly employed techniques. After upstream processing, isolated cells using OS were immunophenotyped to be CD14-, CD34-, CD45-, CD44+, CD105+, and CD106+, and displayed multipotent differentiation. Preliminary investigations to determine mechanisms responsible for osmolytic resistance revealed MSCs to have an ineffective volume of 59%, with the ability to double cell volume at infinite dilution. Disruption of filamentous actin polymerization by cytochalasin D sensitized MSCs to osmotic lysis, which suggests a cytoskeletal element involved in osmolytic resistance.     

人脐血间充质干细胞与β-磷酸三钙的生物相容性

背景：体内实验显示,β-磷酸三钙多孔陶瓷是较为理想的骨组织工程支架材料,但由于体内植入实验受多种因素的影响,不能很好反映细胞的生长、增殖和表型变化。 目的：观察体外人脐血间充质干细胞与β-磷酸三钙多孔陶瓷的生物相容性。 方法：将培养的第6代人脐血间充质干细胞悬液滴注入β-磷酸三钙内部进行复合,然后将干细胞-支架材料复合物置入含体积分数为10%胎牛血清的α-MEM培养体系中培养,于培养第4,8,12天电镜下观察人脐血间充质干细胞在材料表面及内部生长情况,采用MTT测试法绘制细胞生长曲线,并进行DNA含量、蛋白质含量测定。 结果与结论：人脐血间充质干细胞与β-磷酸三钙体外复合后能够在β-磷酸三钙支架材料表面及内部的孔隙内贴附,且生长良好,其DNA复制和蛋白合成功能不受β-磷酸三钙的影响。说明人脐血间充质干细胞和β-磷酸三钙支架材料生物相容性良好,二者可作为种子细胞和支架材料用于组织工程化骨与软骨的构建。     

CD151对人脐带来源间充质干细胞生物学特性的影响

 目的：探讨CD151对人脐带来源间充质干细胞（human umbilical cord mesenchymal stem cells,hUC-MSCs）生物学性状的影响。方法：使用siRNA干扰hUC-MSCs 表面CD151,实验分为实验组（siRNA-CD151组）和对照组（siRNA-NC组）;流式细胞术检测干扰72 h后hUC-MSCs CD151及其它细胞表型,von Kossa和油红O染色检测体外成骨、成脂诱导分化情况;流式细胞术分析细胞周期变化;real-time PCR检测hUC-MSCs CD151、肝细胞生长因子（hepatocyte growth factor,HGF）、转化生长因子β1（transforming growth factor β1,TGF-β1）、环氧合酶2（cyclooxygenase 2,COX-2)和吲哚胺2,3-双加氧酶（indoleamine 2,3-dioxygenase,IDO）mRNA的表达量;ELISA检测hUC-MSCs HGF分泌量。结果：(1) 流式细胞术检测发现干扰72 h hUC-MSCs实验组CD151（11.97±2.63 vs 95.66±1.56;P<0.01）和CD105（93.66±0.21 vs 83.37±0.71;P<0.05）较对照组显著降低;real-time PCR 检测hUC-MSCs CD151 mRNA变化和流式结果一致。(2)给予siRNA-CD151后能够减缓细胞周期进展,表现为细胞G1期增多,S期减少。(3)实验组hUC-MSCs HGF和TGF-β1表达量低于对照组（P<0.01）,而COX-2表达量升高（P<0.05）,IDO无明显改变;ELISA检测显示实验组hUC-MSCs HGF分泌量较对照组下降（P<0.01）。结论：体外干扰CD151后hUC-MSCs 仍保持干细胞表型,体外成脂诱导分化能力无明显变化,但成骨诱导分化能力、增殖能力和相关免疫调节因子表达发生改变。     

人脐带间充质干细胞定向诱导分化成类神经元的实验研究

目的:采用不同细胞因子定向诱导人脐带间充质干细胞分化成类神经元,为脐带间充质干细胞移植治疗脊髓损伤提供理论依据。方法:采用Ⅱ型胶原酶消化法分离培养人脐带间充质干细胞,采用流式细胞术鉴定细胞。取第5代细胞随机分成A、B、C、D 4组,在A组基础培养基中加入b FGF,B组中加入b FGF和BDNF,C组中加入b FGF、BDNF和BHA诱导培养,D组为对照组,使用含有10%胎牛血清的DMEM-F12培养基培养。诱导2周后采用实时荧光定量PCR检测细胞的nestin、NEFH和GFAP mRNA表达情况,并通过原子力显微镜观察细胞超微结构的的变化。结果:Ⅱ型胶原酶消化法能成功分离人脐带间充质干细胞。通过流式细胞术检测第3代细胞发现,细胞均强表达CD29、CD44和CD105,而CD34、CD45和HLA-DR均未见表达。经定向诱导分化成类神经元后,原子力显微镜观察细胞表面突起增多,实时荧光定量PCR检测显示nestin在A、B、C组均呈阳性表达,NEFH在A、B组呈阳性表达,而GFAP在A、B、C、D 4组均不表达。A、B组n EFH和nestin表达具有显著差异(P﹤0.05)。结论:本实验成功分离培养人脐带间充质干细胞,所培养的细胞扩增迅速,生物学性状稳定;与b FGF单独处理相比,b FGF联合BDNF更能有效诱导人脐带间充质干细胞分化成类神经元。