人孤雌胚胎干细胞在人包皮成纤维细胞饲养层上的生长状态

人孤雌胚胎干细胞(human parthenogenetic embryonic stem cells,hPESCs)体外培养常需饲养层的支持以保持干细胞特性.通过原代培养获得人包皮成纤维细胞(human foreskin fibroblasts,hFFs)并将其制备成饲养层,使hPESCs在hFFs上进行体外培养及传代.倒置显微镜下观察hPESCs的生长状态,采用碱性磷酸酶(alkalinephosphatase,AKP)检测、核型分析和体内分化实验研究hPESCs的生物学特性及分化潜能,以探索hFFs能否长期支持hPESCs的生长并维持其未分化状态.经原代培养成功获得了hFFs,通过形态学观察和免疫细胞化学染色鉴定符合成纤维细胞的生物学特性;在hFFs上生长的hPESCs克隆形态规则,不易分化;已成功在体外培养20余代,hPESCs仍能够保持基本生物学特性和正常核型,在裸鼠体内可形成含有3个胚层组织成分的畸胎瘤.作为人源性饲养层,hFFs可长期支持hPESCs的生长并维持其未分化状态.     

人脐带间充质干细胞作为维持人胚胎干细胞生长饲养层细胞的研究

目的寻找可以维持人胚胎干细胞未分化生长的人源性细胞作为饲养层细胞,从而解决使用鼠源性细胞作为饲养层带来的安全问题。方法尝试以人脐带间充质干细胞作为饲养层细胞来培养人胚胎干细胞,检验其是否可以维持人胚胎干细胞的未分化生长状态。用胶原酶消化法分离人脐带间充质干细胞,光镜下观察细胞形态;流式细胞仪检测其表面标志;诱导人脐带间充质干细胞向成骨细胞和脂肪细胞进行分化。将人胚胎干细胞系H1接种于丝裂霉素C灭活后的人脐带间充质干细胞上,每隔5d进行一次传代。培养20代后,对人胚胎干细胞特性进行相关检测,包括细胞形态、碱性磷酸酶染色、相关多能性基因的表达、分化能力。结果从人脐带中分离出的间充质干细胞为梭形,呈平行排列生长或漩涡状生长;细胞高表达CD44、CD29、CD73、CD105、CD90、CD86、CD147、CD117,不表达CD14、CD38、CD133、CD34、CD45、HLA-DR;具有分化成脂肪细胞和成骨细胞的潜能。人胚胎干细胞在人脐带间充质干细胞饲养层上培养20代后,继续保持人胚胎干细胞的典型形态,碱性磷酸酶染色为阳性,免疫荧光染色显示OCT4、Nanog、SSEA4、TRA-1-81、TRA-1-60的表达为阳性,SSEA1表达为阴性,体外悬浮培养可以形成拟胚体。结论人脐带间充质干细胞可以作为人胚胎干细胞的饲养层细胞,支持其生长,并维持其未分化生长状态。     

不同饲养层对鸡胚胎干细胞培养效果的影响

目的:为探索鸡胚胎干细胞培养的优化条件,比较不同饲养层对鸡胚胎干细胞离体培养的效果。方法:用传至第2代的鸡胚成纤维细胞与鸭胚成纤维细胞,经丝裂霉素处理后制作饲养层,比较这2种饲养层以及不用饲养层对鸡胚胎干细胞离体培养效果的影响。结果:在以鸡胚成纤维细胞和鸭胚成纤维细胞作为饲养层的培养体系中,鸡胚胎干细胞均可保持良好的生长状态,而且2种饲养层对鸡胚胎干细胞克隆形成的影响差异不显著(P0.05)。结论:鸡胚成纤维细胞和鸭胚成纤维细胞均可作为较好的饲养层细胞用于鸡胚胎干细胞的离体培养。     

一种新的人胚胎干细胞无饲养层培养方法的建立

目的:以转染碱性成纤维细胞生长因子(bFGF)的人胎肝基质细胞株(FLSC)培养人胚胎干细胞(hESC),寻找更加安全、有效的体外培养扩增方法。方法:通过ELISA方法定量检测转基因的人FLSC条件培养基中bFGF的分泌量;以商业化的mTeSR1无血清无饲养层培养基、常规小鼠胚胎成纤维细胞(MEF)条件培养基,以及转染bFGF的人FLSC条件培养基(bFGF/FLSC-CM)分别培养扩增H9细胞。通过观察hESC形态、免疫荧光染色、流式细胞检测及RT-PCR,检测hESC全能性标志物的表达。结果:ELISA方法检测bFGF/FLSC-CM中bFGF因子的分泌量为(770.09±17.28)pg/mL,而MEF-CM中bFGF因子的分泌量为(55.59±0.61)pg/mL,两者存在显著差异(P0.01);在3种培养体系下,免疫荧光检测hESC全能性标志Oct-4、Tra-1-81抗体的表达均呈阳性,流式检测细胞表面阶段特异性胚胎抗原4(SSEA-4)抗体阳性细胞的比例均在99%左右;RT-PCR检测到hESC特异的转录因子Oct-4、Nanog、Sox-2的表达。结论:以转染bFGF的人FLSC条件培养基可以有效扩增hESC,可为临床应用提供一种安全、高效、低成本的无饲养层培养方法。     

无饲养层培养人胚胎干细胞方法的建立

人胚胎干细胞(human embryonic stem cell,hES细胞)是当前医学研究的热点之一．然而hES细胞培养条件苛刻,通常需要采用鼠胚胎成纤维细胞(mouse embryonic fibroblast,MEFs)饲养层来维持其未分化状态,成为目前hES细胞研究的瓶颈之一、本实验成功地将hES细胞接种在细胞外基质包被的六孔板上培养,传代20次后细胞仍然保持良好的未分化状态,各种hES细胞生物学特性(如表面标志物SSEA-3、SSEA-4、TRA-1-60和TRA-1-8l,OCT-4,碱性磷酸酶及体内外分化潜能等)均无改变;其冻存、复苏效果与生长在饲养层上的hES细胞无明显差异．因此,该无饲养层培养体系可以用于培养hES细胞,并为hES细胞转基因研究及大规模培养打下良好的基础．     

用饲养层分离胚胎干细胞集落的实验初探

目的 用饲养层分离胚胎干细胞集落。方法 用胚龄为13~14 d的小鼠胚胎分离原代成纤维细胞,制成饲养层,用于囊胚的培养。结果 小鼠原代胚胎成纤维细胞（PMEF）贴壁能力较好,增殖快,易铺层。囊胚和内细胞团（ICM）在饲养层上贴壁生长良好,当培养4~5 d时,其增殖率为16/28（57%）。在ICM离散48 h后,各种胚胎干细胞（ES）集落开始出现。此种集落经碱性磷酸酶染色成阳性。结论 用饲养层分离胚胎干细胞获得初步成功。     

人胚胎干细胞传代培养及细胞化学染色特性

目的 体外建立人胚胎干细胞传代培养方法,研究人胚胎干细胞细胞化学染色特性.方法 以小鼠胚胎成纤维细胞作为饲养层传代培养人胚胎干细胞,检测人胚胎干细胞、自发分化克隆及拟胚体的细胞化学染色特性.结果 人胚胎干细胞在小鼠胚胎成纤维细胞饲养层上传30代以上其形态保持不变;人胚胎十细胞碱性磷酸酶、过碘酸-雪夫反应、α-醋酸萘酚酯酶染色阳性,自发分化克隆细胞阳性程度明显减弱;人胚胎干细胞形成的拟胚体碱性磷酸酶染色弱阳性,过碘酸-雪夫反应、α-醋酸萘酚酯酶染色阳性.结论 小鼠胚胎成纤维细胞能支持人胚胎干细胞传代培养,细胞化学染色结果能初步鉴别人胚胎干细胞未分化特性.     

饲养层细胞对绵羊胚胎干细胞体外培养的影响

家畜胚胎干细胞(embryonic stem cell,ES细胞)的研究进展缓慢,绵羊ES细胞的研究虽早有报道,但仍未建立可稳定传代的细胞系。在已建立的绵羊体外受精发育体系的基础上,摸索了饲养层(Feeder)细胞对绵羊ES细胞生长的影响,包括在一定的丝裂霉素浓度下处理Feeder的时间、细胞种类、代数、接种密度及新鲜制备和冷冻复苏后的Feeder细胞,通过试验比较研究,目的在于筛选合适的饲养层细胞,为建立绵羊ES细胞体外培养体系奠定基础。结果表明,10μg/ml丝裂霉素C处理2~2.5h获得的1~5代的SEF和1~3代的MEF及两者的1∶1混合细胞都能较好地支持绵羊ES细胞的生长。     

肌成纤维细胞促进小鼠胚胎肝干细胞的增殖和分化

移植细胞的增殖和分化需要微环境支持。作为最重要的微环境成分,肌成纤维细胞在肿瘤的生长过程中发挥着重要作用。该实验Hepa1-6肿瘤细胞上清液在体外激活成纤维细胞分化为肌成纤维细胞,探讨肌成纤维细胞上清对小鼠胚胎肝干细胞（embryonic hepatic stem cells,EHSCs）HP14.5增殖和分化的影响。实验将EHSCs HP14.5分为三组：DMEM培养液处理组（DMEM组）、成纤维细胞上清液处理组（CMFb组）及肌成纤维细胞上清液处理组（CMAFb组）。MTT法绘制三组HP14.5细胞生长曲线图,免疫荧光法及Real-time PCR法检分别测白蛋白（albumin,ALB）、甲胎蛋白（alpha fetoprotein,AFP）、细胞角蛋白18（cytokeratin 18,CK18）的蛋白及mRNA表达情况,PAS染色法检测糖原合成状况。MTT法检测显示,CMAFb组胚胎肝干细胞增殖明显速度较其他两组快。免疫荧光染色及Real-time PCR结果显示,HP14.5培养5 d后,CMAFb组ALB和CK18的蛋白及mRNA表达水平以及糖原合成水平显著高于CMFb组及DMEM组,而AFP蛋白和mRNA表达水平明显降低。该实验表明,Hepa1-6激活的成纤维细胞能促进胚胎干肝细胞的增殖以及分化为有功能的成熟肝细胞。     

以支持细胞为饲养层培养小鼠精原干细胞

为探索精原干细胞(Spermatogonialstemcells,SSCs)体外自增殖的条件以及SSCs体外快速扩增的方法,以6-8日龄昆明乳鼠为材料,分离小鼠睾丸细胞,采用Percoll梯度离心法富集SSCs;以经丝裂霉素C处理的Sertoli细胞作饲养层,以DMEM为基本培养基,加入5%胎牛血清和103u/ml的白血病抑制因子(Leukemiainhibitoryfactor,LIF),体外培养SSCs;运用免疫荧光技术,以SSCs特异性表面分子Thy1为标志,对原代培养20d和传代培养14d的细胞进行鉴定。该培养体系下,SSCs贴壁时间为6h-9h,48h后可见细胞分裂,迅速增殖出现在接种12d以后。接种后第20d形成数十至上百个细胞的细胞团,细胞总数比接种时增加了45-245倍,100倍显微镜下观察可见,单位视野内细胞团数为26±4个。传代后细胞增殖较快。原代培养20d和传代培养14d的细胞均为Thy1阳性;而传代20d后,细胞周缘不整,有伪足出现,呈现出死亡迹象。该培养条比较适合SSCs短期快速增殖。     

Postmitotic human dermal fibroblasts preserve intact feeder properties for epithelial cell growth after long-term cryopreservation

Summary In vitro, human dermal fibroblasts (HDF) differentiate through morphologically and biochemically identified compartments. In the course of this spontaneous differentiation through mitotic and postmitotic states, a tremendous increase in cellular and nuclear size occurs. Induction of postmitotic states can be accelerated by chemical (e.g., mitomycin C) or physical (e.g., x-ray) treatments. Such experimentally induced postmitotic HDF cells support very efficiently the growth of cutaneous epithelial cells, i.e. interfollicular keratinocytes and follicular outer root sheath cells, especially in primary cultures starting from very low cell seeding densities. The HDF feeder system provides more fundamental and also practical advantages, i.e. use of initially diploid human fibroblasts from known anatomic locations, easy handling and excellent reproducibility, and the possibility of long-term storage by incubation at 37°C. Conditions for the cryogenic storage of postmitotic HDF cells in liquid nitrogen are presented and related to the feeder capacity for epithelial cell growth. Because postmitotic HDF cells preserve intact feeder properties after long-term storage, the immediate availability of feeder cells and the possibility to repeat experiments with identical materials further substantiate the usefulness of this feeder system.     

Effective surface-based cryopreservation of human embryonic stem cells by vitrification

Human embryonic stem cells (hESCs) are candidates for many applications in the areas of regenerative medicine, tissue engineering, basic scientific research as well as pharmacology and toxicology. However, use of hESCs is limited by their sensitivity to freezing and thawing procedures. Hence, this emerging science needs new, reliable preservation methods for the long-term storage of large quantities of functional hESCs remaining pluripotent after post-thawing and culturing.Here, we present a highly efficient, surface based vitrification method for the cryopreservation of large numbers of adherent hESC colonies, using modified cell culture substrates. This technique results in much better post-thaw survival rate compared to cryopreservation in suspension and allows a quick and precise handling and storage of the cells, indicating low differentiation rates.     

Natural killer cells activate human dermal fibroblasts

Human dermal fibroblasts (HDF) undergo activation and secrete cytokines when cocultured with T cells. Here, we identify potent activators of HDF among human peripheral CD2(+)-lymphocytes. Populations with strong HDF activating capacity consisted essentially of cells with a natural killer (NK) surface marker phenotype (CD3(-), CD4(-), CD8(-), CD56(+)). Addition of these cells to HDF resulted in rapid increase of intracellular free calcium concentrations as an early rapid cell activation signal. Upregulation of mRNA encoding for the inflammatory cytokines IL-1 beta and IL-6 as well as for chemokines IL-8 and MCP-1 was detected after cells were cocultured. Elevated concentrations of IL-6 and IL-8 were found in coculture supernatants of HDF and NK-cells. Skin-homing NK cells leaving the blood-stream during an inflammatory skin reaction might therefore represent potent activators of local inflammatory cytokine and chemokine production.     

Quantitative identification of teratoma tissues formed by human embryonic stem cells with TeratomEye

An automated vision system, TeratomEye, was developed for the identification of three representative tissue types: muscle, gut and neural epithelia which are commonly found in teratomas formed from human embryonic stem cells. Muscle tissue, a common structure was identified with an accuracy of 90.3% with high specificity and sensitivity greater than 90%. Gut epithelia were identified with an accuracy of 87.5% with specificity and sensitivity greater than 80%. Neural epithelia which were the most difficult structures to distinguish gave an accuracy of 47.6%. TeratomEye is therefore useful for the automated identification of differentiated tissues in teratoma sections.     

Efficient establishment of human embryonic stem cell lines and long-term maintenance with stable karyotype by enzymatic bulk passage

Human ES (hES) cell lines are considered to be a valuable resource for medical research and for applications in cell therapy and drug discovery. For such utilization of hES cells to be realized, however, protocols involved in the use of hES cells, such as those for establishment, propagation, and cryopreservation, have still to be improved. Here, we report on an efficient method for the establishment of hES cell lines and its detailed characterization. Additionally, we developed a new bulk-passaging technique that preserves the karyotypic integrity of hES cell lines when maintained in culture for up to 2 years. Finally, we show that a simplified vitrification cryopreservation technique is vastly superior to standard slow-cooling methods with respect to cell viability. These results provide valuable information that will assist in achieving the goal of the large-scale hES cell culture required for the application of hES cells to disease therapy.