Early Development and Disease, Murdoch Childrens' Research Institute, Royal Children's Hospital, Flemington Rd, Parkville, VIC 3052, Australia.
Stem Cell Res Ther. 2011 Apr 4;2(2):16. doi: 10.1186/scrt57.
Unrestricted somatic stem cells (USSC) derived from umbilical cord blood are an attractive alternative to human embryonic stem cells (hESC) for cellular therapy. USSC are capable of forming cells representative of all three germ line layers. The aim of this study was to determine the potential of USSC to form definitive endoderm following induction with Activin A, a protein known to specify definitive endoderm formation of hESC.
USSC were cultured for (1) three days with or without 100 ng/ml Activin A in either serum-free, low-serum or serum-containing media, (2) three days with or without 100 ng/ml Activin A in combination with 10 ng/ml FGF4 in pre-induction medium, or (3) four days with or without small molecules Induce Definitive Endoderm (IDE1, 100 nM; IDE2, 200 nM) in serum-free media. Formation of definitive endoderm was assessed using RT-PCR for gene markers of endoderm (Sox17, FOXA2 and TTF1) and lung epithelium (surfactant protein C; SPC) and cystic fibrosis transmembrane conductance regulator; CFTR). The differentiation capacity of Activin A treated USSC was also assessed.
Activin A or IDE1/2 induced formation of Sox17+ definitive endoderm from hESC but not from USSC. Activin A treated USSC retained their capacity to form cells of the ectoderm (nerve), mesoderm (bone) and endoderm (lung). Activin A in combination with FGF4 did not induce formation of Sox17+ definitive endoderm from USSC. USSC express both Activin A receptor subunits at the mRNA and protein level, indicating that these cells are capable of binding Activin A.
Stimulation of the Nodal signaling pathway with Activin A or IDE1/2 is insufficient to induce definitive endoderm formation from USSC, indicating that USSC differ in their stem cell potential from hESC.
来源于脐带血的无限制体干细胞（USSC）是一种有吸引力的替代物，可用于细胞治疗的人类胚胎干细胞（hESC）。USSC 能够形成代表所有三个生殖层的细胞。本研究的目的是确定 USSC 在诱导因子 Activin A 的作用下形成确定的内胚层的潜力，该诱导因子是一种已知指定 hESC 确定内胚层形成的蛋白质。
USSC 在以下条件下培养（1）三天，有或没有 100ng/ml Activin A，在无血清、低血清或含血清的培养基中，（2）三天，有或没有 100ng/ml Activin A，与预诱导培养基中的 10ng/ml FGF4 结合，或（3）四天，有或没有无血清培养基中的小分子诱导确定内胚层（IDE1，100 nM；IDE2，200 nM）。使用 RT-PCR 评估内胚层（Sox17、FOXA2 和 TTF1）和肺上皮（表面活性剂蛋白 C；SPC）和囊性纤维化跨膜电导调节剂的基因标记来评估确定内胚层的形成。还评估了 Activin A 处理的 USSC 的分化能力。
Activin A 或 IDE1/2 从 hESC 诱导 Sox17+确定的内胚层形成，但不能从 USSC 诱导。Activin A 处理的 USSC 保留了形成外胚层（神经）、中胚层（骨骼）和内胚层（肺）细胞的能力。Activin A 与 FGF4 结合不能从 USSC 诱导 Sox17+确定的内胚层形成。USSC 在 mRNA 和蛋白质水平上均表达 Activin A 受体亚单位，表明这些细胞能够结合 Activin A。
用 Activin A 或 IDE1/2 刺激 Nodal 信号通路不足以从 USSC 诱导确定的内胚层形成，表明 USSC 在其干细胞潜力方面与 hESC 不同。
