昆明系小鼠胚胎干细胞分离培养的优化

以昆明系小鼠为对象,经过丝裂霉C处理成纤维细胞(Mouse embryonic fibroblast,MEF)制备饲养层,对影响小鼠胚胎干细胞(Embryonic stem cell,ES细胞)分离培养的相关因素进行研究。分别收集小鼠3.5d的囊胚(扩张囊胚)和4.5d囊胚(孵化囊胚)进行培养,比较扩张囊胚和孵化囊胚的贴壁率、原代克隆率及传代率的情况。收集3.5d胚龄的囊胚,通过全胚法和免疫外科法对内细胞团(Inner cell mass,ICM)进行分离培养ICM集落,确定离散ICM的适宜时间。用0.25%胰酶+0.04%EDTA,0.125%胰酶+0.02%EDTA和0.25%胰酶+1%小鸡血清等方法对小鼠ES细胞集落进行传代,观察不同酶浓度对ES细胞分离克隆的影响。结果显示,孵化囊胚的贴壁率高于扩张囊胚(P0.05),但传代率则相反(P0.05),原代克隆率差异不显著(P0.05);一般ICM增殖培养2～3d(免疫外科法)或4～5d(全胚培养法)后,出现典型的克隆集落,再挑取ICM;0.125%胰酶+0.02%EDTA及0.25%胰酶+1%小鸡血清,形成ES原代克隆率较高,2组没有显著性差异(P0.05);结果表明,分离得到的ES细胞经形态学观察,AKP染色,体外分化试验等表明其具有胚胎干细胞的特性。     

ICR小鼠胚胎干细胞的分离与培养

为了研究不同条件对ICR小鼠ES细胞的影响,试验以12.5~13.5 d ICR小鼠胚胎成纤维细胞(MEF)为饲养层,以3.5 d ICR小鼠胚胎为试验材料,探讨了血清、生长因子及传代方法对ICR小鼠ES细胞分离培养的影响。结果表明:采用含15%FBS的ES细胞培养液的囊胚贴壁率及ICM增殖率(79.3%,69.0%)均比含15%KSR、5%FBS+10%KSR的细胞培养液高(42.9%,28.6%;75.0%,54.2%),ES细胞最高传至6代;培养液中添加10 ng/mL LIF+10 ng/mL SCF的效果比单独添加1种因子的效果好,最高传至6代,高于单独添加1种因子的传代数(4代,2代);用3种传代方法进行传代时,采用差异贴壁法传代效果最佳,最高传至8代,酶消化法传至4代,机械加酶消化法传至6代。     

大鼠心肌条件培养基对ICR小鼠胚胎干细胞分离克隆的影响

采用大鼠心肌条件培养基(RH CM)培养ICR小鼠的桑椹胚和囊胚,发现由囊胚分离的ES细胞传代后ES集落的出现率显著高于桑椹胚(P<0.05),囊胚更适合作为ES细胞分离克隆的材料。以RH CM为培养基的试验组ES细胞传代的平均时间间隔为38 h,对照组传代的时间间隔平均为78 h,两者差异显著(P<0.05)。表明RH CM能够促进ES细胞贴壁增殖和ES集落的形成,有效地维持ES细胞未分化状态。试验中设计的3 种培养条件对原代ES集落的形成影响不显著,但对传代后的ES集落的形成和传代的代次有显著差异。其中以MEF作饲养层,添加RH CM培养基的效果最好。     

ICR小鼠胚胎干细胞的分离与培养

为了研究不同条件对ICR小鼠ES细胞的影响,试验以12.5～13.5 dICR小鼠胚胎成纤维细胞(MEF)为饲养层,以3.5 d ICR小鼠胚胎为试验材料,探讨了血清、生长因子及传代方法对ICR小鼠ES细胞分离培养的影响.结果表明:采用含15%FBS的ES细胞培养液的囊胚贴壁率及ICM增殖率(79.3%,69.0%)均...     

昆明小鼠胚胎收集时间和培养液对囊胚内细胞团集落分离培养的影响

本研究旨在筛选获取优质ICM集落的实验方法。以昆明系小鼠为实验动物,采集3.5、4 d和4.5 d的胚胎,分别移入DMEM培养液、DMEM+白血病抑制因子(LIF)和小鼠胎儿成纤维细胞共培养体系中进行培养,观察比较内细胞团(ICM)从透明带中孵出的时间、孵化囊胚贴壁情况以及ICM集落形成情况。结果表明:妊娠3.5 d的胚胎61%为桑椹胚,需要经过4～5 d的体外培养才能形成ICM集落;妊娠4 d的扩张囊胚经过3～4 d的共培养后形成ICM集落;妊娠4.5 d的孵化囊胚经过1～2 d的共培养即可形成ICM集落;ICM形成率以妊娠4.5 d的胚胎最高,显著高于妊娠4 d和3.5 d的胚胎(P<0.01),但妊娠4.5 d冲出孵化囊胚数量显著降低(P<0.01);小鼠胎儿成纤维细胞共培养体系优于DMEM和DMEM+LIF培养液。因此,采集妊娠4 d的昆明小鼠胚胎,选择小鼠胎儿成纤维细胞共培养体系,在体外培养3～4 d,能够有效分离培养出可用于胚胎干细胞研究的优质ICM。     

ICR小鼠胚胎干细胞体外培养体系的优化

为了优化ICR小鼠胚胎干细胞体外培养体系,本实验以ICR小鼠胚胎成纤维细胞(MEF)为饲养层,以3.5dICR小鼠胚胎为试验材料,探讨了不同胚胎发育阶段、不同胰岛素添加量和不同生长因子对ICR小鼠类胚胎干细胞(mESCs)分离培养的影响。实验结果表明:囊胚期的胚胎贴壁率和内细胞团(inner cell mass,ICM)集落增殖率(82.4%、64.7%)显著高于桑葚胚期(54.2%、41.7%)(P0.05);在添加不同浓度胰岛素时,0、5、10mg/mL组的胚胎贴壁率和ICM集落增殖率差异均不显著(P0.05);添加生长因子组的胚胎贴壁率和ICM集落增殖率显著优于未添加组(P0.05),而添加组中单独添加SCF稍逊于单独添加LIF和2种因子一起添加的效果。     

由体外受精囊胚获得ICR小鼠ES细胞

收集鼠卵母细胞和精子，采用体外受精技术，获得早期胚胎。体外培养胚胎至囊胚，分离内细胞团，获得ICR小鼠的ES细胞。结果不但获得了来自体外受精囊胚的ICR小鼠ES细胞，而且表明用体外受精方法获得的小鼠早期胚胎的数量明显大于常规方法，且比较稳定。ICR小鼠ES细胞的获得，为研究小鼠的ES细胞分化提供了条件。     

猪孤雌胚胎干细胞建系的研究

以猪孤雌激活囊胚为材料,囊胚透明带消化后采用全胚培养,培养液中添加不同培养成分或因子（如FGF2,LIF,2i等）,以及选择不同的初始培养液体积来筛选猪胚胎干细胞（embryonic stem cell,ES细胞）建系的优化培养体系。囊胚内细胞团形成的细胞集落采用胰酶消化传代。结果显示：透明带消化后,囊胚贴壁率显著升高（19．4％VS．8．8％）（P〈0．05）;初始培养液体积比平常培养液体积（0．30mL／孔,24孔培养板）减半条件下,能显著提高其贴壁率（91．7％VS 20．0％）（P〈0．01）,而且获得了可传至7代的类ES细胞系2株,碱性磷酸酶染色成阳性;当用2i因子（CHIR99021和PD03025901）去替代培养液中的FGF2,囊胚贴壁率（29．400VS53．3％）和原代集落形成率（20．0％VS 87．5％）反而显著下降（P〈0．01）。这表明培养液添加了FGF2和LIF（不舍2i因子）,用24孔板培养,最初培养体积为0．15mL,透明带消化的培养体系比较适合猪孤雌激活胚的ES细胞建系。     

山羊类ES细胞的分离与克隆

采集山羊交配后6～8d的桑椹胚、囊胚和孵化囊胚,将桑椹胚和囊胚分别放在小鼠原代胎儿成纤维细胞(PMEF)饲养层和同源原代胎儿成纤维细胞(PGEF)饲养层上比较其脱带时间及脱带率。脱带后,将各自一半胚胎切割,把含ICM的半胚分别放在相应饲养层上进行培养,另一半整胚在各自饲养层上继续培养,而孵化囊胚直接于PGEF饲养层上培养。当ICM增殖一定程度时进行传代,以比较其类ES细胞分离与克隆的效果。结果表明,在2种不同饲养层上,囊胚的脱带时间均短于桑椹胚,囊胚的脱带率均高于桑椹胚,而饲养层的种类对胚胎的脱带时间以及脱带率影响不大。脱带切割囊胚不论在PMEF还是在PGEF饲养层上,其贴壁时间均短于脱带整胚及孵化囊胚,而贴壁率高于脱带整胚,与孵化囊胚相似。脱带整胚及脱带切割胚在PMEF饲养层上所获类ES细胞只能维持3代,而在PGEF饲养层上,脱带切割半胚和孵化囊胚所获类ES细胞传至5代。由此认为,对脱带后的胚胎进行切割处理,有利于ICM的贴壁和增殖;应用同源原代胎儿成纤维细胞饲养层培养系统,有利于类ES细胞的分离与克隆。     

小鼠皮肤成纤维细胞的体细胞核移植

取成年小鼠唇部皮肤进行培养，分离成纤维细胞并血清饥饿培养1周，用作核供体。对成年小鼠进行超排，取卵母细胞用作核受体，核移植重构胚经SrCl2激活处理6h后，同mM16培养液和小鼠输卵管上皮细胞共培养，把发育到早期囊胚的重构胚转移至小鼠胎儿成纤维细胞饲养层上，添加ES细胞条件培养液，消化分离ICM，然后接种培养，对孵出的ES细胞样集落进行鉴定培养。结果显示，小鼠唇部皮肤成纤维细胞为核供体，核移植重构胚2-细胞率为54．05％，桑椹胚率17．14％，囊胚率6．90％，对照组卵丘细胞的核移植重构胚2-细胞率为60．00％，桑椹胚率21．85％，囊胚率11．69％，但2种供体细胞在支持核移植重构胚发育能力上差异不显著。成纤维细胞重构囊胚中6个囊胚分离出ES细胞样集落，3个ES细胞样集落可稳定传代；对照组卵丘细胞重构囊胚中9个囊胚中分离出ES细胞样集落，5个ES细胞样集落可稳定传代。从核移植重构胚中分离出的ES细胞样集落具有岛状或巢状群体生长形态，生长旺盛的集落可自发分化成单个散在或片状存在的上皮样或梭形细胞，碱性磷酸酶检测为阳性，常规冻存复苏，仍显示ES细胞特征。     

Improved isolation and culture of embryonic stem cells from Chinese miniature pig

Pigs serve as a better research model for human beings than other species. The Chinese laboratory miniature pig is a new laboratory animal and is expected to be applicable in many medical research fields. This study was to establish effective technologies to isolate and culture ES cells in Chinese miniature pigs. For isolation of the inner cell mass from blastocysts, an enzyme-digestive method was compared with the traditional immunosurgery. Isolated ICM were cultured in three feeder cell layers: mouse embryonic fibroblasts (MEF), porcine embryonic fibroblasts (PEF) and a continuous cell line of mouse embryonic fibroblasts (STO). Microtubule activity of the three feeder cells was further examined by immunofluorescence. ICM were successfully isolated from 85% of blastocysts by the enzyme-digestive method, compared to only 40% by immunosurgery. When ICM were cultured in three feeder layers for two to three days, 75%, 65% and 20% of ICMs formed primary cell colonies in MEF, PEF and STO, respectively. Colonies were also formed during subcultures after 9, 5 and 1 passage in MEF, PEF and STO, respectively. Microtubules in STO cells were significantly fewer than those in MEF and PEF. When the ES-like cells were cultured in a differentiation medium, they differentiated to neuron-like cells and other types of cells. These results indicate that healthier ICM can be obtained with the enzyme-digestive method. Successful culture of ICM to ES-like cells has been achieved not only in MEF, but also in homologous (pig) feeder layer. The ES cells obtained in the present study were pluripotent.     

Buffalo (Bubalus bubalis) Embryonic Stem Cell‐Like Cells and Preimplantation Embryos Exhibit Comparable Expression of Pluripotency‐Related Antigens

In this study, inner cell mass (ICM) cells were isolated from in vitro produced buffalo blastocysts and were cultured on mitomycin‐C treated buffalo foetal fibroblast feeder layer for producing embryonic stem (ES) cells. Among different sources (hatched vs expanded blastocysts) or methods (enzymatic vs mechanical), mechanical isolation of ICM from hatched blastocysts resulted in the highest primary colony formation rate and the maximum passage number up to which ES cells survived. Putative ES cells expressed alkaline phosphatase and exhibited a normal karyotype up to passage 7. Putative ES cells and embryos at 2‐ to 4‐cell, 8‐ to 16‐cell, morula and blastocyst stages strongly expressed stage‐specific embryonic antigen (SSEA)‐4 but lacked expressions of SSEA‐1 and SSEA‐3. Putative ES cells also expressed tumour rejection antigen (TRA)‐1‐60, TRA‐1‐81 and Oct4. Whereas in all early embryonic stages, TRA‐1‐60 was observed only in the periplasmic space, and TRA‐1‐81 expression was observed as small spots at a few places inside the embryos, both these markers were expressed by ICM. Oct4 expression, which was observed at all the embryonic stages and also in the trophectoderm, was the strongest in the ICM. Buffalo putative ES cells possess a unique pluripotency‐related surface antigen phenotype, which resembles that of the ICM.     

影响体外培养兔胚发育和兔类ES细胞分离的若干因素

本试验系统地比较了影响兔囊胚体外培养和免类ＥＳ细胞系分离的几个主要因素。结果表明，３种不同糖浓度（４．５，１．０，０．２ｇ／Ｌ）在４８ｈ内对胚胎贴壁均无显著影响。在高糖ＤＭＥＭ中，早期胚胎内细胞团（ｉｎｎｅｒｃｅｌｌｍａｓｓ，ＩＣＭ）增殖速度最快，分化也快；超低糖组，ＩＣＭ增殖缓慢，分化出现时间较晚；低糖组，ＩＣＭ既能保持较快的增殖速度，又能维持较长时间的未分化状。高糖组和低糖组的ＥＳ细胞样集落的传代能力相似，可达６～７代，超低糖组中不超过２代。胰岛素能促进ＩＣＭ的增殖，并可提高传代过程中ＥＳ细胞样克隆的形成率。在小鼠胚胎原代成纤维细胞（ＭＥＦ）和一种经白血病抑制因子转化了的小鼠成纤维细胞系（ＳＮＬ）上，ＩＣＭ都能维持较快的增殖速度，在家兔胚胎原代成纤维细胞（ＲＥＦ）中ＩＣＭ增殖较慢，无饲养细胞条件下，ＩＣＭ存活率低，生长状况不佳。传代能力，ＲＥＦ要比ＭＥＦ和ＳＮＬ低，且主要形成上皮样集落。作者根据以上实验结果认为，用低糖ＤＭＥＭ为基本培养基，再加入胰岛素，在ＭＥＦ或ＳＮＬ上培养切割胚胎和连续传代的技术路线是较为可行的。     

小鼠胚胎干细胞培养、克隆、分离、传代研究

对影响小鼠胚胎干细胞（Embryonic stem cells,ES细胞）培养、克隆、分离、传代效果的因素进行了探索研究。应用223枚昆明白小鼠胚胎和20枚129品系小鼠胚胎的研究结果表明，129品系小鼠胚胎比昆明白小鼠胚胎更适合作为ES细胞建系的材料，两者FS出现率差异显著（P＜0．05）；以DMEM＋10％NBS＋10％FCS为基础培养液，分别加入LIF、胰岛素、LIF＋SCF，极显著提高昆明白小鼠胚胎贴壁率，ICM生长率及F1、F2出现率（P＜0．01），而在DMEM＋10％NBS＋10％FCS＋LIF＋SCF为培养液，得到昆明白小鼠胚胎最高贴壁率、ICM生长率及传代率；4dpc胚胎传代情况显著好于3．5dpc胚胎（P＜0．05）。