人胚胎干细胞优化培养的进展

Progress in the optimal culture of human embryonic stem cell

人胚胎干细胞(humanembryonicstemcell,hEScell)是来源于着床前人囊胚内细胞团(innercellmass,ICM)的、具有自我更新能力和分化全能性的细胞。由于hES细胞能在一定条件下分化成三个胚层来源的各种细胞,所以它具有重要的基础研究价值和巨大的临床应用前景,可应用于人早期胚胎发育过程的研究、药物毒物筛选、细胞移植治疗、基因治疗等领域。目前,世界上已经建立了多株hES细胞系,最早建立的hES细胞系是生长在小鼠胚胎成纤维(mouseembryonicfibroblast,MEF)细胞上的,培养体系中含血清等动物源性成分,这些成分可能引起动物源性病原体或支原体的污染,从而限制了hES细胞的临床应用。近年来,科学家们在优化hES细胞的体外培养体系方面做出了很大的努力并取得了长足进展,已经开始采用无血清、无饲养层细胞、无外源性蛋白、成分明确的培养体系进行hES细胞建系及培养,从而在一定程度上解决了上述问题。本文主要从饲养层细胞、无饲养层培养体系、培养基质、细胞因子等方面综述了hES细胞建系和维持其未分化状态的优化培养所取得的最新进展和存在的问题。

Human embryonic stem （hES） cells are pluripotent cells derived from the inner cell mass （ICM） cells of preimplantation blastocysts with the potential to self-renew and differentiate. As hES cells can be induced to differentiate into numerous cell types of all three germ layers under in vitro and in vivo conditions, they are potentially valuable for the basic research and clinical application, including researches on development of early human embryo, screening drugs and toxins, cell transplantation, gene therapy, etc. Many hES cell lines have been established under different conditions in the world. The firstly established hES cell lines were cultured on mouse embryonic fibroblast （MEF） cells with medium containing many undefined animal components such as fetal bovine serum, which may cause cross-transfection with animal pathogen and mycoplasm. In recent years, scientists had made great efforts to optimize the culture conditions for hES cells and achieved considerable progresses forward. Today, hES cells are derived and cultured under defined serum-free and feeder-free conditions without xenogeneic proteins, which to some extent solved the problems mentioned above. In this review, We will discuss the new progresses and unsolved issues on optimizing culture conditions for hES derivation and maintaining its undifferentiated state, mainly about feeder cell layer, feeder-free culture system, matrix and cytokines.