诱导多能干细胞建系及体外造血祖细胞定向分化体系的建立

Systematic establishment for directed differentiation of induced pluripotent stem cells into hematopoietic progenitor cells in vitro

背景:目前,大量文献报道了诱导多能性干细胞系的建立,但大规模体外诱导分化造血祖细胞的研究还缺乏深入的探讨。目的:建立诱导多能性干细胞体外定向诱导形成造血祖细胞的方法。方法:采用慢病毒感染的方法将含有Oct4、Sox2、Nanog和Lin28全能性基因的慢病毒颗粒转导人皮肤成纤维细胞,获得了诱导多能性干细胞;在诱导分化体系中添加了Y-27632,克服干细胞扩增中的凋亡现象;运用OP9细胞产生的条件培养液建立诱导多能性干细胞体外定向分化形成造血祖细胞的分化体系。结果与结论:①前3代细胞克隆传代时,诱导多能性干细胞发生凋亡的现象很多,很难大规模扩增培养。培养基中添加阻断ROCK活化的抑制剂,能够明显抑制胚胎干细胞的凋亡。②诱导多能性干细胞在OP9细胞条件培养液作用下,经过体外诱导分化,形成CD34+造血祖细胞。

BACKGROUND：There have been a large number of reports on establishing induced pluripotent stem celllines, but studies concerning large-scale in vitro induced differentiation of induced pluripotent stem cels into hematopoietic progenitor cels stil have a lack of in-depth discussion. OBJECTIVE：To develop methods to induce differentiation of induced pluripotent stem cels into hematopoietic progenitor cels in vitro. METHODS： Using the method of infection with lentivirus particles containing four transcriptionfactor genes, which are Oct4, Sox2, Nanog and Lin28, human skin fibroblasts are transduced into induced pluripotent stem cels. In the induced differentiation system, Y-27632, a kind of tyrosine kinase inhibitor-ROCK （p160-Rho-associated coiled-coil kinase）, was added, which obviously suppressed apoptosis of cels. Based on conditioned medium with OP9 cels, a differentiation system of inducing induced pluripotent stem cels differentiating into hematopoietic progenitor cels was established. RESULTS AND CONCLUSION：（1） Apoptosis of induced pluripotent stem cels at the first three passages was very obvious, and the cels were difficult in a large-scale expansion. After Y-27632 was added, the apoptosis of embryonic stem cels was obviously inhibited. （2） During embryoid body differentiation, induced pluripotent stem cels cultured in OP9 conditional growth medium differentiated into hematopoietic progenitor celsin vitro that were positive for CD34.