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。     

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）。     

提高猪囊胚后期贴壁能力的优化培养体系

为了提高猪孤雌囊胚贴壁率,试验从饲养层及培养液两方面研究猪孤雌囊胚贴壁能力;用小鼠、猪和牛的胎儿成纤维细胞制作饲养层,分别添加DMEM、NCSU-23、DMEM/NCSU-23培养液,探讨猪孤雌囊胚在3种饲养层上的发育效果。结果表明,BEF饲养层能更好地促进猪孤雌囊胚贴壁生长,其囊胚贴壁率为33.67%,与MEF饲养层组的囊胚贴壁率(19.08%)之间差异显著(P0.05),与PEF饲养层组之间囊胚贴壁率差异不显著(P0.05),MEF饲养层组和PEF饲养层组之间囊胚贴壁率差异不显著(P0.05);在BEF牛胎儿成纤维细胞饲养层组,用猪胚胎培养液NCSU-23培养猪孤雌囊胚后,囊胚贴壁率(22.53%)显著高于DMEM培养液组(10.41%)和DMEM/NCSU-23培养液半量混合组(12.05%)(P0.05),DMEM培养液组和DMEM/NCSU-23培养液半量混合组之间差异不显著(P0.05)。牛胎儿成纤维细胞饲养层和猪胚胎培养液NCSU-23能更好地促进猪孤雌囊胚后期贴壁。     

ICR小鼠胚胎干细胞建系初步研究

实验旨在探讨消化方式和胚胎发育阶段对ICR小鼠胚胎干细胞(ES细胞)建系效率的影响。ICR小鼠3.5 d囊胚在饲养层上贴壁后采用单一酶消化或机械化与酶消化法相结合分离隆起的细胞集落,进行传代培养;然后选择二者中较优消化方式对不同发育时期囊胚所形成的细胞集落进行处理。结果表明:采用机械化与胰酶消化相结合的方式,形成的类ES细胞超过7代的比率(85.0%)要显著高于单一的胰酶消化(15.0%)(P<0.05);当用二者相结合的方式对ICR小鼠3.5 d(早期囊胚)、4.0 d(扩张囊胚)和4.5 d(孵化囊胚)所形成的细胞集落进行消化传代培养,三者在贴壁率和形成原代细胞集落率上均无显著差别(P>0.05),但传代超过7代的效率上早期囊胚和扩张囊胚均高于孵化囊胚(P<0.05)。结果提示,采用机械化与酶消化法相结合更适合于3.5～4.0 d ICR小鼠囊胚的ES细胞建系。     

牛体外受精胚胎衍生干细胞能力影响因素的研究

以牛卵巢卵母细胞体外受精获取囊胚期胚胎，比较体外受精牛胚胎不同获取内细胞团的方法和不同培养液对体外培养胚胎干细胞能力的影响。结果表明，囊胚期胚胎不除去透明带而直接培养产生胚胎干细胞，初次克隆率为55％；胰酶法去透明带分离的内细胞团（ICM）培养产生胚胎干细胞，初次克隆率为90％。免疫外科法去透明带分离的ICM在4种不同的培养液中，初次克隆率分别为16．4％、11．5％、21．8％、18．2％，但是其分离的ICM经传代后形成的衍生细胞不易发生分化，经过4～6代的传代，仍然保持其完整的形态，说明免疫外科法是一种理想的牛ICM分离法，培养液为D20＋LIF（40ng／mL）可用于牛胚胎干细胞培养。     

奶牛耳成纤维细胞的分离培养及培养条件的研究

本试验研究了奶牛耳成纤维细胞的体外培养,培养液、消化液、胰岛素和血清饥饿对细胞的影响。采用组织块贴壁法培养。了奶牛耳成纤维细胞,采用0．25％胰酶差别消化获得了纯化的奶牛耳成纤维细胞。用三种不同的培养液即DMEM（低糖）、DMEM（高糖）、DMEM／F12,对细胞进行培养,结果细胞群体倍增时间均在2．3-2．5d,DMEM（高糖）的培养效果稍好。用三种不同的消化液（0．25％胰蛋白酶,0.02％EDTA,0．25％胰蛋白酶＋0．02％EDTA）对传代钿跑进行消化．结果表明0．25％胰蛋白酶＋0D2％EDTA所用时间短,消化后培养细胞贴壁率高。在培养液中添加姨岛素能促进细胞的生长。对指数生长期的细胞进行血清饥饿后,细胞仍保持着较高的活力。     

饲养层和生长因子对山羊类胚胎干细胞的影响

实验以6~8 d的山羊囊胚为实验材料,采用机械法分离山羊囊胚ICM,分别以小鼠和山羊胚胎成纤维细胞作饲养层,并采用含不同生长因子的培养液进行培养,比较了饲养层和生长因子对分离培养山羊类ES细胞的影响。结果表明:采用MEF饲养层其ICM增殖率优于GEF饲养层;与对照组相比,培养液中添加LIF及SCF或胰岛素对山羊ICM的贴壁增殖及传代都有积极影响;以MEF为饲养层,培养液中同时添加LIF和SCF时,培养山羊类ES细胞的效果最佳,传至3代。     

影响昆明小鼠和BALB/c小鼠胚胎干细胞分离、克隆、传代的若干因素

对昆明小鼠和BALB／c小鼠2种胚胎的研究表明，2种品系小鼠胚胎均可用作胚胎干细胞（ES）分离建系的材料，两者在ES分离、传代上无显著差异（P〉0．05）；大鼠心肌细胞条件培养液与添加LIF的ES常规培养液相比，显著提高了小鼠ES细胞F1、F2出现率（P〈0．05）；采用低浓度消化液使形成ES克隆的比率分别从14％、16％提高到35％、32％，使ES传到第5代的比率分别从1．7％、0提高到5％、7．1％；而采用连续消化法使形成ES克隆的比率从15％、17％提高到40％、50％，使ES传到第5代的比率从0、1％提高到10％、20％；对ES进行伊红染色、核型分析、AKP染色及体外分化能力检测，证实所分离的ES符合小鼠ES的一系列特征。     

由牛体外受精胚胎分离胚胎干细胞

以DMEM＋15％NBS＋0．1mmol/Lβ－巯基乙醇＋0．01μmol/L亚硒酸钠＋10μg/L LIF＋10μg/L IGF－1作为培养液，以原代小鼠胎儿成纤维细胞为饲养层，利用8日龄牛体外受精胚胎获得了传3代的牛类胚胎干细胞（类ES细胞）。通过体外分析试验，对所得类ES细胞的多能性进行了鉴定。结果在培养2d后，牛类ES细胞分化形成了类似于扩张囊胚的结构，悬浮于培养液中。     

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。     

Enhancing effects of serum-rich and cytokine-supplemented culture conditions on developing blastocysts and deriving porcine parthenogenetic embryonic stem cells

The present study was conducted to develop an effective method for establishment of porcine parthenogenetic embryonic stem cells (ppESCs) from parthenogenetically activated oocyte-derived blastocysts. The addition of 10% fetal bovine serum (FBS) to the medium on the 3rd day of oocyte culturing improved the development of blastocysts, attachment of inner cell masses (ICMs) onto feeder cells, and formation of primitive ppESC colonies. ICM attachment was further enhanced by basic fibroblast growth factor, stem cell factor, and leukemia inhibitory factor. From these attached ICMs, seven ppESC lines were established. ppESC pluripotency was verified by strong enzymatic alkaline phosphatase activity and the expression of pluripotent markers OCT3/4, Nanog, and SSEA4. Moreover, the ppESCs were induced to form an embryoid body and teratoma. Differentiation into three germ layers (ectoderm, mesoderm, and endoderm) was confirmed by the expression of specific markers for the layers and histological analysis. In conclusion, data from the present study suggested that our modified culture conditions using FBS and cytokines are highly useful for improving the generation of pluripotent ppESCs.     

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.     

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。     

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。     

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。     

绵羊类胚胎干细胞的分离与克隆

从胚胎发育阶段、饲养层和培养体系等方面对影响绵羊类ES细胞分离、克隆效率的因素进行探讨。结果显示：致密桑葚胚和囊胚的ICM增殖率高于囊胚和孵化囊胚。绵羊类ES细胞在同源绵羊胎儿成纤维细胞（SEF）上生长比较缓慢,最终传代次数也低于小鼠胎儿成纤维细胞（MEF）组。培养液中同时添加胎牛血清（FBS）和Knock-out血清替代品（KSR）,绵羊类ES传至7代,添加了碱性成纤维细胞生长因子（bFGF）后,最高可传至8代,而单纯添加KSR或FBS,分别传至4代和5代。对类ES细胞进行AKP染色、核型分析、体外分化试验,证实分离的类ES细胞符合ES细胞的主要特征,而且表达多潜能性细胞因子Nanog。由此认为,致密桑葚胚和囊胚更适合绵羊类ES细胞的体外分离和培养,而且MEF更适合于绵羊类ES细胞的分离传代,培养液中添加5%FBS和15%KSR,比较适合类ES细胞的分离传代,bFGF对绵羊类ES细胞的增殖具有促进作用。     

In vitro culture of bovine embryos in murine ES cell conditioned media negatively affects expression of pluripotency-related markers OCT4, SOX2 and SSEA1

Despite extensive efforts, establishment of bovine embryonic stem (ES) cell lines has not been successful. We hypothesized that culture conditions for in vitro-produced (IVP) embryos, the most used source of inner cell mass (ICM) to obtain ES cells, might affect their undifferentiated state. Therefore, the aim of this work was to improve pluripotency of IVP blastocysts to produce suitable ICM for further culturing. We tested KSR and foetal calf serum (FCS) supplements in SOF medium and ES cell conditioned medium (CM) on IVC (groups: KSR, KSR CM, FCS and FCS CM). Cleavage and blastocyst rates were similar between all groups. Also, embryonic quality, assessed by apoptosis rates (TUNEL assay), total cell number and ICM percentage did not differ between experimental groups. However, expression of pluripotency-related markers was affected. We detected down-regulation of OCT3/4, SOX2 and SSEA1 in ICM of FCS CM blastocysts (p < 0.05). SOX2 gene expression revealed lower levels (p < 0.05) on KSR CM blastocysts and a remarkable variation in SOX2 mRNA levels on FCS-supplemented blastocysts. In conclusion, pluripotency-related markers tend to decrease after supplementation with ES cell CM, suggesting different mechanisms regulating mouse and bovine pluripotency. KSR supplementation did not differ from FCS, but FCS replacement by KSR may produce blastocysts with stable SOX2 gene expression levels.