胚胎干细胞向造血细胞分化研究

胚胎干（embryonic stem，ES）细胞是来源于囊胚的内细胞团（inner cell mass，ICM），具有发育的全能性或多能性，能嵌合到早期胚胎，在体内可以参与各种组织发育甚至包括生殖细胞；在体外分化培养条件下，可以顺序分化出各种组织细胞，与体内完整胚胎发育过程相符合，而且可以通过调节ES细胞某些基因的表达而调节其分化。因此，ES细胞是研究哺乳动物早期胚胎发育、细胞分化及其关键基因鉴定的理想模型。另外，胚胎生殖脊（embryonic germ，EG）细胞系也具有同样的生物学特性，它是由早期胚胎的原始生殖脊（primordial germ，PG）细胞建株而来。最近研究显示：ES细胞在体外不但可以分化为所有造血细胞系，而且还可以分化为具有长期增殖能力的造血干细胞。作者就胚胎干细胞向造血细胞和造血干细胞分化及其诱导因子和调控基因的表达作一综述。

Differentiation of embryonic stem cells into hematopoietic cells

Embryonic stern (ES) cells have been derived from the inner cell mass cells of blas-tocytes, and are totipotent or pluripotent cells, and can be chimerised into early embryo, and developed in vivo into many tissue specific cells including germ cells. In vitro, ES cells can differentiate into multicellular aggregates of differentiated and undifferentiated cells, termed embryoid bodies(EBs), when cultured in suspension without inhibitory factors of differentiation, including a wide variety of cell types, and can generate neural cells, vascular endotheliurn, muscle colls, and endodermal derivatives, etc. In addition, similar pluripotent cell lines have been derived from the primordial germ cells of the developing gonadal ridge in early embryos, termed embryonic germ (EG) cells. Here, we will review the differentiation of ES cells into hematopoietic cells. The growth and expression characteristics of these EB-derived cells suggest that they are relatively uncommitted precursor or progenitor cells. EB-derived hematopoietic cells may play a role in future transplantation therapies.