犊牛睾丸生殖干细胞与支持细胞体外共培养体系的建立

旨在建立牛雄性生殖干细胞(mGSCs)-支持细胞(SCs)体外共培养体系,并比较不同密度SCs共培养mGSCs的效果。分离、培养mGSCs和SCs并鉴定,然后在密度不同的SCs上共培养mGSCs,观察细胞形态、统计mGSCs集落数、测定两种细胞特异基因的相对表达量。结果表明,培养的mGSCs具有与小鼠mGSCs相同的形态特征,AKP染色细胞克隆阳性,各培养体系均表达SCs和mGSCs特异基因SCF、OCT-4;低密度SCs(225个/cm2)培养mGSCs比中密度(1 300个/cm2)和高密度(5 600个/cm2)培养mGSCs效果好:mGSCs集落纯度、体积较大;mGSCs集落比例显著(P0.05)和极显著增高(P0.01);mGSCs特异基因表达量均极显著增高(P0.01)。说明建立睾丸干细胞体外共培养体系时,采用较低密度的支持细胞共培养可获得理想的睾丸生殖干细胞。     

猪雄性生殖干细胞的分离纯化

 为了建立猪雄性生殖干细胞的分离纯化方法,以1~2周龄长白猪睾丸组织为材料,采用差异贴壁法和曲细精管培养法对猪雄性生殖干细胞进行分离纯化。结果表明：双酶消化-差异贴壁法和曲细精管培养法均能获得高活力的猪雄性生殖干细胞,但后者的富集效果较好,可以达到40.7%,前者的富集效果为 36.9%。差异贴壁法和曲细精管培养法具有操作简单、回收细胞纯度高等优点,可应用于猪雄性生殖干细胞的分离纯化。     

新生牛雄性生殖细胞源类ES的培养及检测

采用贴壁速率差法分离纯化的新生牛雄性生殖干细胞（Male germ stem cell，mGSCs）和支持细胞（Calf sertoli cell，CSCs）；CSCs饲养层细胞一般维持时间不超过8d；新生牛雄性生殖干细胞在CSCs饲养层上1代培养至5～6d可形成类ES细胞集落，采用机械离散集落传代法有利于集落形成或存在，传代培养至少在前2代细胞集落存在；部分典型细胞集落的中心细胞AKP强阳性，周边细胞AKP弱阳性或阴性；免疫组化检测显示，细胞集落SSEA1强阳性、SSEA3弱阳性和Oct-4呈现阳性染色。表明mGSCs具有ES细胞的某些细胞特性。     

睾丸支持细胞可促进鸡精原干细胞体外增殖

正扬州大学的研究人员比较了层黏连蛋白、纤维连接蛋白、胶原蛋白以及睾丸支持细胞4种不同培养系统对鸡精原干细胞(SSCs)体外增殖的作用效果。采用三酶两步消化法分离SSCs,细胞经明胶差速纯化后培养,将传至3代的SSCs重新接种于层黏连蛋白、纤维连接蛋白和胶原蛋白包被的培养皿中以及睾丸支持细胞制备的饲养层上,通过形态学、5-乙基-2′-脱氧尿嘧啶核苷(EDU)细胞增殖、qRT-PCR技术检测不同培养系统对鸡精原干细胞体外增殖的作用效果。结果表明:三组基质蛋白及睾丸支持细胞都能够促进鸡SSCs的体外     

Retinol促进小鼠雄性生殖干细胞的增殖

Retinol(RE)作为维生素A的一种,对生命有机体内多种生理生化和代谢反应均有重要的影响.本试验以雄性生殖干细胞(mGSCs)为对象,用RE培养mGSCs,探讨RE对mGSCs增殖的影响.试验分别设置对照组,RE组,RE+LY(LY294002,PI3K抑制剂)组,RE+PD(PD98059,MAPKK抑制剂)组.选取培养不同时间的mGSCs进行半定量与定量PCR分析,检测基因的表达情况.对培养48h的mGSCs进行Brdu荧光染色.结果显示,RE培养能够显著促进mGSCs的增殖,培养后C-myc等增殖标记基因表达上调,加入LY、PD抑制剂后,增殖效果显著降低；表明RE可能通过PI3K或MAPKK促进mGSCs的增殖.本研究证明了RE具有促进mGSCs增殖的作用,对于探明RE对mGSCs增殖调控的机理具有重要意义.     

枸杞多糖对山羊精原细胞体外增殖的影响

为研究枸杞多糖对山羊精原干细胞体外增殖的影响,使用机械分离法、两步酶解法及差速贴壁获取纯度较高的山羊精原干细胞,使用碱性磷酸酶(AKP)染色法及免疫荧光染色法对山羊SSCs进行鉴定;通过添加不同浓度的LBP培养山羊精原干细胞,利用CCK-8法检测细胞增殖数量,筛选最佳体外培养浓度;分别测试细胞丙二醛(MDA)、超氧化物...     

红景天多糖对幼鼠精原干细胞体外增殖的影响

为研究如何在体外获得更好的精原干细胞培养效果,以出生后6～8 d的小鼠为对象,应用两步酶消化法和差速贴壁法分离纯化精原干细胞.分别将浓度为100、200、300和400 ng/mL的红景天多糖加入以Sertoli细胞为饲养层的精原干细胞培养液中,以不添加红景天多糖组为对照,通过RT-PCR法和碱性磷酸酶（AP）染色鉴定细胞,MTT法研究红景天多糖对精原干细胞增殖的影响.RT-PCR和染色结果显示,分离得到的细胞为精原干细胞;MTT结果显示试验组比对照组细胞数量有显著增多（P＜0.05）,增殖率可达152％,且红景天多糖的最适添加量300 ng/mL.说明红景天多糖能显著促进小鼠精原干细胞的体外增殖.     

山羊雄性胎儿生殖细胞建立干细胞系初探

体外培养山羊50~68日龄雄性胎儿生殖细胞,并检测它们的碱性磷酸酶(AP)活性和Oct-4蛋白,探讨性别分化后的生殖细胞用于建立干细胞系的可行性及检测指标。当山羊胎儿睾丸细胞体外培养时,生殖细胞及其来源的细胞克隆均呈AP阴性和Oct-4蛋白阴性,其中有部分细胞克隆表现为AP假阳性。山羊胎儿生殖细胞克隆呈隆突状生长,多为圆形,与周围细胞界限分明,但克隆内细胞间界限不清。细胞克隆至少可以培养3代以上。研究结果显示,山羊雄性胎儿生殖细胞可以用于建立生殖系来源的干细胞系;AP和Oct-4蛋白不适宜用来检测体外培养的山羊胎儿生殖细胞及其来源的细胞系。     

猪小肠粘膜上皮细胞的分离及体外原代培养模型的建立

用机械刮取小肠粘膜加胶原酶Ⅱ消化的方法,采用新生未吮乳仔猪小肠组织,成功地分离了猪小肠粘膜上皮细胞(Intestinal epithelial cells,IEC)且在体外培养传代,并采用碱性磷酸酶和角蛋白免疫学试验鉴定,结果表明:体外培养的猪IEC在DMEM-F12培养基中,细胞在1~2d贴壁,5~6d形成细胞克隆,9~11d融合成片;碱性磷酸酶和生物素标记的细胞角蛋白抗体鉴定结果显示90%培养的细胞为阳性,分别从生化的角度证明和细胞生物学角度鉴定了所培养的细胞为IEC。     

成年牛睾丸组织体外无血清培养研究

为研究促进精子发生的体外培养体系,通过无血清睾丸组织培养法,将成年牛睾丸组织块种植于培养板, 观测不同时间睾丸细胞的迁出和形态变化。通过油红O染色鉴定具有分泌功能的支持细胞,通过碱性磷酸酶和免疫组化染色鉴定集落样生长的精原干细胞。结果发现该体系可获得生长良好的多种类型细胞,包括表达AP、Oct-4和GFRα1的精原干细胞及具有分泌功能的睾丸支持细胞,并可获得大量精子。说明,该无血清培养体系可作为一个重要的工具来研究生物学和化学因素对雄性生殖系统的影响,也为研究精子体外发生和移植提供了材料。     

p53 inhibits the proliferation of male germline stem cells from dairy goat cultured on poly-L-lysine

Male germline stem cells (mGSCs) can transmit genetic materials to the next generation and dedifferentiate into pluripotent stem cells. However, in livestock, mGSC lines are difficult to establish, because of the factors that affect their isolation and culture. The extracellular matrix serves as a substrate for attachment and affects the fate of these stem cells. Poly-L-lysine (PL), an extracellular matrix of choice, inhibits and/or kills cancer cells, and promotes the attachment of stem cells in culture. However, how it affects the characteristics and potentials of these stem cells in culture needs to be elucidated. Here, we isolated, enriched and cultured dairy goat mGSCs on five types of extracellular matrices. To explore the best extracellular matrix to use for culturing them, the characteristics and proliferation ability of the cells were determined. Results showed that the cells shared several characteristics with previously reported mGSCs, including the poor effect of PL on their proliferative and colony-forming abilities. Further examination showed upregulation of p53 expression in these cells, which could be inhibiting their proliferation. When a p53 inhibitor was included in the culture medium, it was confirmed to be responsible for the inhibition of proliferation in mGSCs. Optimal concentration of the inhibitor in the culture of these cells was 5 µM. Furthermore, addition of the p53 inhibitor increased the expression of the markers of self-renewal and cell cycle in goat mGSCs. In summary, suppressing p53 is beneficial for the proliferation of dairy goat mGSCs, cultured on PL.     

Isolation and culture of rabbit primordial germ cells

Primordial germ cells (PGCs) are embryonic precursors of the gametes of adult animals and are considered stem cells of the germline. Since their proliferation in vitro correlates well with the schedule of developmental changes in vivo, they might be interesting research tools for genomic imprinting, germ-cell tumors and fertility. Furthermore, once primordial germ cells are separated and placed on a feeder layer with cytokines, they become cultured pluripotent cell lines called embryonic germ (EG) cells. EG cells share several important characteristics with embryonic stem (ES) cells as they can also contribute to the germ line of chimeras. To investigate the characteristics of PGCs and establish rabbit EG (rEG) cells, we cultured rabbit PGCs (rPGCs) in vitro with various combinations of leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF) and forskolin on inactivated mouse embryonic fibroblast (MEF) feeder layers. The present study found PGC proliferation in early cultures and induction of rEG-like colonies. These cells expressed pluripotent markers, such as alkaline phosphatase activity, OCT-4, Sox-2 and SSEA-1, in the undifferentiated state; however, the cells did not develop into a teratoma when injected into the kidney capsules of SCID mice, although the restricted differentiation potentials to neural cells were determined via embryoid body formation. From these characteristics and further characterization of the germ stem cell markers Vasa, SCP-1 and SCP-3, we suggested that these were hybrid cells with characteristics somewhere between PGC and EG cells.     

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.     

Analysis of marker expression in porcine cell lines derived from blastocysts produced in vitro and in vivo

The present study was designed to extensively characterize cell lines derived from porcine blastocysts by several methodical approaches, including morphological observation, cytogenetic analysis, estimation of alkaline phosphatase activity and detection of specific marker expression at the mRNA/protein level. A comparison was made between the properties of cell lines isolated from in vivo- and in vitro-obtained blastocysts. Our results showed that 57.1% of the in vivo-obtained blastocysts attached to the feeder layer and that 33.3% of them started to grow in a monolayer. The percentage of attached in vitro-produced blastocysts was lower (24.6%), and only 6.9% of them started to grow. Outgrowths from the in vitro-produced blastocysts formed mainly trophectoderm or epithelial-like monolayer, whereas the in vivo-obtained blastocysts formed heterogeneous outgrowths that also contained cells with embryonic stem (ES)-like morphology. Detailed analyses showed that the primary outgrowths with ES-like morphology expressed the pluripotency markers OCT-4 and NANOG and revealed intensive alkaline phosphatase staining, while they did not express markers of differentiation. The majority of passaged cells, including those with ES-like morphology, lacked OCT-4 protein and revealed expression of specific differentiation markers (cytokeratin 18, lamins A/C, transferrin, α-fetoprotein and GATA-4), although they still expressed NANOG and exhibited weak alkaline phosphatase activity. Moreover, these cells spontaneously differentiated into neural, fibroblast or epithelial-like cells, even in the presence of leukaemia inhibitory factor. Our results show that complex analysis of markers of pluripotency as well as differentiation markers is necessary for proper interpretation of data in porcine embryonic stem cell studies.     

猪多潜能干细胞系的研究进展

猪多潜能干细胞是在体外建立起来的具有自我更新及三胚层分化潜能的一类干细胞,可应用于发育生物学研究、基因组编辑和疾病模型建立等各方面,在畜牧业生产及再生医学研究中具有重要的应用价值。培养体系对多潜能干细胞的成功构建具有重要意义,其包含多种成分,包括基础培养液、氨基酸等营养成分、小分子化合物(信号通路激活剂/抑制剂及细胞因子)共同维持细胞的多能性并抑制其分化。目前已有诸多关于猪多潜能干细胞的报道,但尚未获得高效的培养体系可以维持猪多潜能干细胞的长期传代并完成生殖嵌合。猪多潜能干细胞可分为原始态(Na6ve)、形成态(Formative)及始发态(Primed)3种不同多能性的状态特点,根据建系来源的不同分为猪扩展多潜能干细胞、猪胚胎干细胞、猪前原肠胚上胚层干细胞、猪诱导多能干细胞4种干细胞类型。作者综述了猪多潜能干细胞培养体系中常用的细胞因子和信号通路激活剂/抑制剂对猪多潜能干细胞的多能性和分化能力的影响和作用,为进一步建立具有真正生殖嵌合能力的Na6ve多能性的猪多潜能干细胞系提供研究思路。     

Generation of embryonic stem‐like cells from in vivo‐derived porcine blastocysts at a low concentration of basic fibroblast growth factor

Although basic fibroblast growth factor (bFGF) is an essential factor supporting the maintenance of porcine embryonic stem (ES) cell self‐renewal and pluripotency, its high cost has limited previous studies, and the development of a low‐cost culture system is required. For these systems, in vivo blastocysts were progressively cultured under various conditions consisting of different culture mediums and/or different feeder cell numbers at a low concentration of bFGF. As the results, the sequential culture of in vivo‐derived porcine blastocysts on 5.0 × 10⁵ mouse embryonic fibroblast (MEF) feeder cells in alpha minimum essential medium‐based medium for primary culture, on 2.5 × 10⁵ MEF feeder cells in Mixture medium for the 1st subpassage, and on 2.5 × 10⁵ MEF feeder cells in DMEM/Ham's F10‐based medium for the post‐2nd subpassage could support the establishment and maintenance of porcine ES‐like cells at the low concentration of bFGF. The established porcine ES‐like cells showed ES cell‐specific characteristics such as self‐renewal and pluripotency. We confirmed that porcine ES‐like cells could be generated from in vivo‐derived porcine blastocysts at a low concentration of bFGF.     

Maintenance of mouse trophoblast stem cells in KSR-based medium allows conventional 3D culture

Mouse trophoblast stem cells (TSCs) can differentiate into trophoblast cells, which constitute the placenta. Under conventional culture conditions, in a medium supplemented with 20% fetal bovine serum (FBS), fibroblast growth factor 4 (FGF4), and heparin and in the presence of mouse embryonic fibroblast cells (MEFs) as feeder cells, TSCs maintain their undifferentiated, proliferative status. MEFs can be replaced by a 70% MEF-conditioned medium (MEF-CM) or by TGF-ß/activin A. To find out if KnockOut^TM Serum Replacement (KSR) can replace FBS for TSC maintenance, we cultured mouse TSCs in KSR-based, FBS-free medium and investigated their proliferation capacity, stemness, and differentiation potential. The results indicated that fibronectin, vitronectin, or laminin coating was necessary for adhesion of TSCs under KSR-based conditions but not for their survival or proliferation. While the presence of FGF4, heparin, and activin A was not sufficient to support the proliferation of TSCs, the addition of a pan-retinoic acid receptor inverse agonist and a ROCK-inhibitor yielded a proliferation rate comparable to that obtained under the conventional FBS-based conditions. TSCs cultured under the KSR-based conditions had a gene expression and DNA methylation profile characteristic of TSCs and exhibited a differentiation potential. Moreover, under KSR-based conditions, we could obtain a suspension culture of TSCs using extracellular matrix (ECM) coating-free dishes. Thus, we have established here, KSR-based culture conditions for the maintenance of TSCs, which should be useful for future studies.