title: Substrate stiffness affects early differentiation events in embryonic stem cells.
abstract: Embryonic stem cells (ESC) are both a potential source of cells for tissue replacement therapies and an accessible tool to model early embryonic development. Chemical factors such as soluble growth factors and insoluble components of the extracellular matrix are known to affect the differentiation of murine ESCs. However, there is also evidence to suggest that undifferentiated cells can both sense the mechanical properties of their environment and differentiate accordingly. By growing ESCs on flexible polydimethylsiloxane substrates with varying stiffness, we tested the hypothesis that substrate stiffness can influence ESC differentiation. While cell attachment was unaffected by the stiffness of the growth substrate, cell spreading and cell growth were all increased as a function of substrate stiffness. Similarly, several genes expressed in the primitive streak during gastrulation and implicated in early mesendoderm differentiation, such as Brachyury, Mixl1 and Eomes, were upregulated in cell cultures on stiffer compared to softer substrates. Finally, we demonstrated that osteogenic differentiation of ESCs was enhanced on stiff substrates compared to soft substrates, illustrating that the mechanical environment can play a role in both early and terminal ESC differentiation. Our results suggest a fundamental role for mechanosensing in mammalian development and illustrate that the mechanical environment should be taken into consideration when engineering implantable scaffolds or when producing therapeutically relevant cell populations in vitro.
authors.affiliation: Department of Materials, Imperial College London, London, UK.
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Evans
authors.forename: Caterina
authors.initials: C
authors.lastname: Minelli
authors.forename: Eileen
authors.initials: E
authors.lastname: Gentleman
authors.forename: Vanessa
authors.initials: V
authors.lastname: LaPointe
authors.forename: Sameer N
authors.initials: SN
authors.lastname: Patankar
authors.forename: Maria
authors.initials: M
authors.lastname: Kallivretaki
authors.forename: Xinyong
authors.initials: X
authors.lastname: Chen
authors.forename: Clive J
authors.initials: CJ
authors.lastname: Roberts
authors.forename: Molly M
authors.initials: MM
authors.lastname: Stevens
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004129:Dimethylpolysiloxanes / Q000737:chemistry / Q000494:pharmacology*; D004548:Elasticity; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005326:Fetal Proteins / Q000235:genetics; D051521:Fibroblast Growth Factor 5 / Q000235:genetics; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D050993:GATA6 Transcription Factor / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D051542:Hepatocyte Nuclear Factor 3-beta / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D051379:Mice; D000071317:Nanog Homeobox Protein; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055748:SOXB1 Transcription Factors / Q000235:genetics; D020825:T-Box Domain Proteins / Q000235:genetics; D013997:Time Factors; D000098908:Brachyury Protein
chemical_list: D004129:Dimethylpolysiloxanes; D005326:Fetal Proteins; D051521:Fibroblast Growth Factor 5; D051417:Focal Adhesion Kinase 1; D050993:GATA6 Transcription Factor; D051542:Hepatocyte Nuclear Factor 3-beta; D018398:Homeodomain Proteins; D000071317:Nanog Homeobox Protein; D055748:SOXB1 Transcription Factors; D020825:T-Box Domain Proteins; D000098908:Brachyury Protein; C496450:Fgf5 protein, mouse; C496503:Foxa2 protein, mouse; C494760:Gata6 protein, mouse; C475540:Nanog protein, mouse; C098693:Sox1 protein, mouse; C013830:baysilon; C496051:Ptk2 protein, mouse