Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
J R Soc Interface. 2013 Apr 3;10(83):20130139. doi: 10.1098/rsif.2013.0139. Print 2013 Jun 6.
The cell-substrate interface plays a key role in the regulation of cell behaviour. Defining the properties of this interface is particularly important for human embryonic stem (hES) cell culture, because changes in this environment can regulate hES cell differentiation. It has been established that fibronectin-coated surfaces can promote the attachment, growth and maintenance of the undifferentiated phenotype of hES cells. We investigated the influence of the surface density of adsorbed fibronectin on hES cell behaviour in defined serum-free culture conditions and demonstrated that only 25 per cent surface saturation was required to maintain attachment, growth and maintenance of the undifferentiated phenotype. The influence of surface-adsorbed fibronectin fragments was compared with whole fibronectin, and it was demonstrated that the 120 kDa fragment central binding domain alone was able to sustain hES cells in an undifferentiated phenotype in a similar fashion to fibronectin. Furthermore, hES cell attachment to both fibronectin and the 120 kDa fragment was mediated by integrin α5β1. However, although a substrate-attached synthetic arginine-glycine-aspartic acid (RGD) peptide alone was able to promote the attachment and spreading of fibroblasts, it was inactive for hES cells, indicating that stem cells have different requirements in order to attach and spread on the central fibronectin RGD-cell-binding domain. This study provides further information on the characteristics of the cell-substrate interface required to control hES cell behaviour in clearly defined serum-free conditions, which are needed for the development of therapeutic applications of hES cells.
细胞-基质界面在调节细胞行为方面起着关键作用。定义这个界面的特性对于人胚胎干细胞（hES）细胞培养尤为重要，因为这种环境的变化可以调节 hES 细胞的分化。已经证实，纤连蛋白涂层表面可以促进 hES 细胞的附着、生长和未分化表型的维持。我们研究了吸附纤连蛋白的表面密度对 hES 细胞在无血清定义培养条件下行为的影响，并证明仅需要 25%的表面饱和度即可维持附着、生长和未分化表型的维持。我们比较了表面吸附的纤连蛋白片段与完整纤连蛋白的影响，结果表明，仅 120 kDa 片段的中央结合域就能够以类似于纤连蛋白的方式维持 hES 细胞的未分化表型。此外，hES 细胞对纤连蛋白和 120 kDa 片段的附着都由整合素 α5β1 介导。然而，尽管单独的基质附着合成精氨酸-甘氨酸-天冬氨酸（RGD）肽能够促进成纤维细胞的附着和扩展，但它对 hES 细胞不起作用，这表明干细胞在附着和扩展到中央纤连蛋白 RGD-细胞结合域时具有不同的要求。这项研究提供了更多关于在明确无血清条件下控制 hES 细胞行为所需的细胞-基质界面特性的信息，这对于开发 hES 细胞的治疗应用是必要的。
