Van Vranken B E, Romanska H M, Polak J M, Rippon H J, Shannon J M, Bishop A E
Tissue Engineering and Regenerative Medicine Centre, Imperial College Faculty of Medicine, Chelsea and Westminster Campus, London, UK.
Tissue Eng. 2005 Jul-Aug;11(7-8):1177-87. doi: 10.1089/ten.2005.11.1177.
Coculture of stem/progenitor cells with mature cells or tissues can drive their differentiation toward required lineages. Thus, we hypothesized that coculture of murine embryonic stem (ES) cells with embryonic mesenchyme from distal lung promotes the differentiation of pneumocytes. Murine ES cells were differentiated to embryoid bodies (EBs) and cultured for 5 or 12 days with pulmonary mesenchyme from embryonic day 11.5 or 13.5 murine embryos, in direct contact or separated by a membrane. Controls included EBs cultured alone or with embryonic gut mesenchyme. Histology revealed epithelium-lined channels in directly cocultured EBs, whereas EBs grown alone showed little structural organization. The lining cells expressed cytokeratin and thyroid transcription factor 1, an early developmental marker in pulmonary epithelium. Differentiation of type II pneumocytes specifically was demonstrated by the presence of surfactant protein C (SP-C) in some of the epithelial cells. None of these markers was seen in EBs cultured alone or with embryonic gut mesenchyme. Indirect coculture of EBs with lung mesenchyme resulted in a 14-fold increase in SP-C gene expression. Thus, provision of an appropriate microenvironment, in the form of pulmonary mesenchyme, appears to promote the differentiation of ES cells toward lung epithelium. Our findings may have applications in regenerative medicine strategies and the engineering of lung tissue.
将干细胞/祖细胞与成熟细胞或组织共培养可促使它们向所需谱系分化。因此，我们推测将小鼠胚胎干细胞（ES细胞）与远端肺的胚胎间充质共培养可促进肺细胞的分化。将小鼠ES细胞分化为胚状体（EBs），并与来自胚胎第11.5天或13.5天小鼠胚胎的肺间充质直接接触或通过膜分隔培养5天或12天。对照组包括单独培养的EBs或与胚胎肠间充质共培养的EBs。组织学检查显示，直接共培养的EBs中有上皮衬里的通道，而单独培养的EBs几乎没有结构组织。衬里细胞表达细胞角蛋白和甲状腺转录因子1，这是肺上皮早期发育的标志物。一些上皮细胞中存在表面活性蛋白C（SP-C），这证明了II型肺细胞的特异性分化。在单独培养的EBs或与胚胎肠间充质共培养的EBs中均未观察到这些标志物。EBs与肺间充质的间接共培养导致SP-C基因表达增加了14倍。因此，以肺间充质的形式提供合适的微环境似乎可以促进ES细胞向肺上皮细胞的分化。我们的研究结果可能在再生医学策略和肺组织工程中有应用价值。
