Task Keith, D'Amore Antonio, Singh Satish, Candiello Joe, Jaramillo Maria, Wagner William R, Kumta Prashant, Banerjee Ipsita
Department of Chemical Engineering, University of Pittsburgh, , Pittsburgh, PA, USA.
J R Soc Interface. 2014 Apr 9;11(95):20140009. doi: 10.1098/rsif.2014.0009. Print 2014 Jun 6.
Stem cells receive numerous cues from their associated substrate that help to govern their behaviour. However, identification of influential substrate characteristics poses difficulties because of their complex nature. In this study, we developed an integrated experimental and systems level modelling approach to investigate and identify specific substrate features influencing differentiation of mouse embryonic stem cells (mESCs) on a model fibrous substrate, fibrin. We synthesized a range of fibrin gels by varying fibrinogen and thrombin concentrations, which led to a range of substrate stiffness and microstructure. mESCs were cultured on each of these gels, and characterization of the differentiated cells revealed a strong influence of substrate modulation on gene expression patterning. To identify specific substrate features influencing differentiation, the substrate microstructure was quantified by image analysis and correlated with stem cell gene expression patterns using a statistical model. Significant correlations were observed between differentiation and microstructure features, specifically fibre alignment. Furthermore, this relationship occurred in a lineage-specific manner towards endoderm. This systems level approach allows for identification of specific substrate features from a complex material which are influential to cellular behaviour. Such analysis may be effective in guiding the design of scaffolds with specific properties for tissue engineering applications.
干细胞会从其相关的基质中接收大量有助于调控其行为的信号。然而，由于其性质复杂，确定有影响力的基质特征存在困难。在本研究中，我们开发了一种综合实验和系统层面建模的方法，以研究和识别在模型纤维基质纤维蛋白上影响小鼠胚胎干细胞（mESC）分化的特定基质特征。我们通过改变纤维蛋白原和凝血酶浓度合成了一系列纤维蛋白凝胶，这导致了一系列的基质硬度和微观结构。将mESC培养在这些凝胶中的每一种上，对分化细胞的表征揭示了基质调节对基因表达模式有强烈影响。为了识别影响分化的特定基质特征，通过图像分析对基质微观结构进行量化，并使用统计模型将其与干细胞基因表达模式相关联。在分化与微观结构特征之间观察到显著相关性，特别是纤维排列。此外，这种关系以内胚层特异性的方式出现。这种系统层面的方法能够从复杂材料中识别出对细胞行为有影响的特定基质特征。这样的分析可能有效地指导具有特定性质的支架设计，用于组织工程应用。
