人羊膜上皮细胞的研究进展

Research progress in human amniotic epithelial cells

人羊膜上皮细胞源于胎盘羊膜组织,表达干细胞标志分子及相关基因,但不表达端粒酶基因,具有非致瘤性,同种异体移植后不发生免疫排斥反应,同时还可分泌免疫抑制因子,防止移植后炎性反应的发生,因此可以看作是免疫赦免细胞。人羊膜上皮细胞具有明显的可塑性和多向分化潜能,在不同生长因子的调节下,可分化为肝样细胞、心肌样细胞、神经胶质细胞、神经元细胞和胰岛样细胞等,在细胞替代治疗及组织再生医学上有广阔的应用前景。尽管如此,仍还不能将人羊膜上皮细胞称之为严格定义上的干细胞,因其不具有长期的自我更新和产生单个细胞克隆的能力,此外人羊膜细胞在体内分化成有功能的各种细胞类型需要进一步研究证实。

Human amniotic epithelial cells are derived from placental amniotic membrane. They express stem cell markers and related gene, but not telomerase gene. Human amniotic epithelial cells also appear to express low level of MHC-I and not to express MHC-II so that immunological rejection does not take place after allograft. In addition, they can secrete immunosuppression factors that can prevent inflammatory reaction postgraft. Human amniotic epithelial cells have obvious plasticity and capacity of multi-directional differentiation. Under the regulation of different growth factors, they can differentiate into many kinds of cells, such as hepatocyte-like cells, cardiomyocyte-like cells, neuroglial cells, nerve cells, pancreatic islet-like cells and so on. Thus human amniotic epithelial cells are promising in cell substitute treatment and tissue regeneration medicine. However, we cannot call it ＂stem cell＂, because it lacks of the capacity of long-term self-renewal and production of single cell colony. Additionally, the classification of functional cells differentiated from human amniotic epithelial cells in vivo needs further validation.