摘 要：摘 要：干细胞是存在于胚胎和成体中的一类特殊细胞，它能长期地自我更新，在特定的条件下具有分化形成多种终末细胞的能力，不同来源的干细胞分化潜能各异。从早期胚胎内细胞团分离的胚胎干细胞能分化形成个体所有的细胞类型，并具有在体外无限增殖的能力，是最具有临床应用前景和研究价值的干细胞之一。在成体各种组织和器官中也存在成体干细胞，用于维持机体结构和功能的稳态。近期有关成体干细胞可塑性的研究和成体组织中多能干细胞存在的证据扩大了人们对成体干细胞分化潜能的认识。干细胞具有的多向分化潜能和自我更新能力使其成为未来再生医学的重要种子细胞，并成为研究人类早期胚层特化和器官形成、药物筛选以及基因治疗的最佳工具。
关键词：干细胞；分化；多能性；胚胎干细胞；成体干细胞；可塑性
Abstract: Abstract: Stem cells are specialized cell types in the embryonic and adult tissue. They have the ability of long term self-renewal and could give rise to various terminal differentiated cell types in specific condition. Stem cells from different origin have different differentiation potential. Embryonic stem cells derived from early pre-implantation embryo have the capacity to differentiate into all cell types in the body and could infinitely proliferate in vitro, which are considered to be one of the most valuable stem cells for future clinical application and research purpose. Adult stem cells exist in various adult tissues and organs and play a role in maintaining the structural and functional homeostasis of the body. Recent researches on the plasticity of adult stem cells and evidences of existence of pluripotent stem cells in the adult tissues broaden our view on the differentiation potential of adult stem cells. The ability of multiple lineage differentiation and long term self-renewal make stem cells to be the most important "seed cells" in future regenerative medicine and the best tool for the research in human early germ layer specification and organogenesis, drug screen and gene therapy.
Key words: stem cells; differentiation; pluripotency; embryonic stem cells; adult stem cells; plasticity
