A paracrine regulation was recently proposed in human embryonic stem cells （hESCs） grown in mouse embryonic fibroblast （MEF）-conditioned media （MEF-CM）, where hESCs spontaneously differentiate into autologous fi...A paracrine regulation was recently proposed in human embryonic stem cells （hESCs） grown in mouse embryonic fibroblast （MEF）-conditioned media （MEF-CM）, where hESCs spontaneously differentiate into autologous fibroblastlike cells to maintain culture homeostasis by producing TGF-β and insulin-like growth factor-lI （IGF-Ⅱ） in response to basic fibroblast growth factor （bFGF）. Although the importance of TGF-β family members in the maintenance of pluripotency of hESCs is widely established, very little is known about the role of IGF-Ⅱ. In order to ease hESC cul- ture conditions and to reduce xenogenic components, we sought （i） to determine whether hESCs can be maintained stable and pluripotent using CM from human foreskin fibroblasts （HFFs） and human mesenchymal stem cells （hM- SCs） rather than MEF-CM, and （ii） to analyze whether the cooperation of bFGF with TGF-β and IGF-Ⅱ to maintain hESCs in MEF-CM may be extrapolated to hESCs maintained in allogeneic mesenchymal stem cell （MSC）-CM and HFF-CM. We found that MSCs and HFFs express all FGF receptors （FGFR1-4） and specifically produce TGF-β in response to bFGF. However, HFFs but not MSCs secrete IGF-Ⅱ. Despite the absence of IGF-Ⅱ in MSC-CM, hESC pluripotency and culture homeostasis were successfully maintained in MSC-CM for over 37 passages. Human ESCs derived on MSCs and hESCs maintained in MSC-CM retained hESC morphology, euploidy, expression of surface markers and transcription factors linked to pluripotency and displayed in vitro and in vivo multilineage developmental potential, suggesting that IGF-Ⅱ may be dispensable for hESC pluripotency. In fact, IGF-Ⅱ blocking had no effect on the homeostasis of hESC cultures maintained either on HFF-CM or on MSC-CM. These data indicate that hESCs are successfully maintained feeder-free with IGF-Ⅱ-lacking MSC-CM, and that the previously proposed paracrine mechanism by which bFGF cooperates with TGF-β and IGF-Ⅱ in the maintenance of hESCs in MEF-CM may not be fully extrapolated to hESCs maintained in CM from human MSCs.展开更多
鸡胚胎干细胞(cES)以其全能性,在研究胚胎发育生物学和家禽育种等方面有巨大的应用前景。本实验旨在建立cES无饲养层培养体系和对LipofactiminTMLTX(脂质体)介导转染体系进行优化。采用药匙法从新鲜受精蛋中分离获取cES,接种于层粘连蛋...鸡胚胎干细胞(cES)以其全能性,在研究胚胎发育生物学和家禽育种等方面有巨大的应用前景。本实验旨在建立cES无饲养层培养体系和对LipofactiminTMLTX(脂质体)介导转染体系进行优化。采用药匙法从新鲜受精蛋中分离获取cES,接种于层粘连蛋白包被的培养皿,待形成大克隆后,用口吸管剥离法吸取cES克隆进行消化传代,并采用生化和免疫学方法鉴定其干细胞活性。设计质粒量800、900、1 000 ng 3个水平,质粒、脂质体比为1∶1.5、1∶2、1∶2.5体系转染cES。结果表明:无饲养层培养体系体外培养cES细胞能稳定传代至第6代,鉴定结果显示碱性磷酸酶阳性和阶段特异性胚胎抗原1阳性,指明克隆能保持未分化状态;质粒900 ng、质脂比为1∶2时,可获得最佳转染效率72%,为cES的脂质体介导外源基因的转染提供参考。展开更多
文摘A paracrine regulation was recently proposed in human embryonic stem cells （hESCs） grown in mouse embryonic fibroblast （MEF）-conditioned media （MEF-CM）, where hESCs spontaneously differentiate into autologous fibroblastlike cells to maintain culture homeostasis by producing TGF-β and insulin-like growth factor-lI （IGF-Ⅱ） in response to basic fibroblast growth factor （bFGF）. Although the importance of TGF-β family members in the maintenance of pluripotency of hESCs is widely established, very little is known about the role of IGF-Ⅱ. In order to ease hESC cul- ture conditions and to reduce xenogenic components, we sought （i） to determine whether hESCs can be maintained stable and pluripotent using CM from human foreskin fibroblasts （HFFs） and human mesenchymal stem cells （hM- SCs） rather than MEF-CM, and （ii） to analyze whether the cooperation of bFGF with TGF-β and IGF-Ⅱ to maintain hESCs in MEF-CM may be extrapolated to hESCs maintained in allogeneic mesenchymal stem cell （MSC）-CM and HFF-CM. We found that MSCs and HFFs express all FGF receptors （FGFR1-4） and specifically produce TGF-β in response to bFGF. However, HFFs but not MSCs secrete IGF-Ⅱ. Despite the absence of IGF-Ⅱ in MSC-CM, hESC pluripotency and culture homeostasis were successfully maintained in MSC-CM for over 37 passages. Human ESCs derived on MSCs and hESCs maintained in MSC-CM retained hESC morphology, euploidy, expression of surface markers and transcription factors linked to pluripotency and displayed in vitro and in vivo multilineage developmental potential, suggesting that IGF-Ⅱ may be dispensable for hESC pluripotency. In fact, IGF-Ⅱ blocking had no effect on the homeostasis of hESC cultures maintained either on HFF-CM or on MSC-CM. These data indicate that hESCs are successfully maintained feeder-free with IGF-Ⅱ-lacking MSC-CM, and that the previously proposed paracrine mechanism by which bFGF cooperates with TGF-β and IGF-Ⅱ in the maintenance of hESCs in MEF-CM may not be fully extrapolated to hESCs maintained in CM from human MSCs.
文摘鸡胚胎干细胞(cES)以其全能性,在研究胚胎发育生物学和家禽育种等方面有巨大的应用前景。本实验旨在建立cES无饲养层培养体系和对LipofactiminTMLTX(脂质体)介导转染体系进行优化。采用药匙法从新鲜受精蛋中分离获取cES,接种于层粘连蛋白包被的培养皿,待形成大克隆后,用口吸管剥离法吸取cES克隆进行消化传代,并采用生化和免疫学方法鉴定其干细胞活性。设计质粒量800、900、1 000 ng 3个水平,质粒、脂质体比为1∶1.5、1∶2、1∶2.5体系转染cES。结果表明:无饲养层培养体系体外培养cES细胞能稳定传代至第6代,鉴定结果显示碱性磷酸酶阳性和阶段特异性胚胎抗原1阳性,指明克隆能保持未分化状态;质粒900 ng、质脂比为1∶2时,可获得最佳转染效率72%,为cES的脂质体介导外源基因的转染提供参考。
