Abstract
Pluripotent stem cells are uniquely capable of differentiating into somatic cell derivatives of all three germ lineages, therefore holding tremendous promise for developmental biology studies and regenerative medicine therapies. Although temporal patterns of phenotypic gene expression have been relatively well characterized during the course of differentiation, coincident patterns of endogenous extracellular matrix (ECM) and growth factor expression that accompany pluripotent stem cell differentiation remain much less well-defined. Thus, the objective of this study was to examine the global dynamic profiles of ECM and growth factor genes associated with early stages of pluripotent mouse embryonic stem cell (ESC) differentiation. Gene expression analysis of ECM and growth factors by ESCs differentiating as embryoid bodies for up to 14 days was assessed using PCR arrays (172 unique genes total), and the results were examined using a variety of data mining methods. As expected, decreases in the expression of genes regulating pluripotent stem cell fate preceded subsequent increases in morphogen expression associated with differentiation. Pathway analysis generated solely from ECM and growth factor gene expression highlighted morphogenic cell processes within the embryoid bodies, such as cell growth, migration, and intercellular signaling, that are required for primitive tissue and organ developmental events. In addition, systems analysis of ECM and growth factor gene expression alone identified intracellular molecules and signaling pathways involved in the progression of pluripotent stem cell differentiation that were not contained within the array data set. Overall, these studies represent a novel framework to dissect the complex, dynamic nature of the extracellular biochemical milieu of stem cell microenvironments that regulate pluripotent cell fate decisions and morphogenesis.
Highlights
For three decades, embryonic stem cells (ESCs) have been used as a model of mammalian developmental morphogenesis in order to define and characterize mechanisms of self-renewal and differentiation of pluripotent cells [1,2,3]
embryoid bodies’’ (EBs) differentiation The time course of EB differentiation was examined by morphology and phenotypic markers prior to performing semiglobal gene expression analysis
The coincident decrease in pluripotency and increase in germ lineage marker expression, as well as the EB morphological changes that occurred over 14 days of suspension culture were consistent with previous studies from our laboratory [30,33,34] that reflect progressive differentiation of EB populations
Summary
Embryonic stem cells (ESCs) have been used as a model of mammalian developmental morphogenesis in order to define and characterize mechanisms of self-renewal and differentiation of pluripotent cells [1,2,3]. ESCs are commonly induced to differentiate via the spontaneous assembly of cell aggregates in suspension referred to as ‘‘embryoid bodies’’ (EBs) [9,10]. The temporal sequence of ESC differentiation that occurs spontaneously within EBs recapitulates several aspects of early embryogenesis, including gastrulation of the cells to yield derivatives of the three germ lineages – ecto-, endo-, and mesoderm [4,9]. While most studies of ESC differentiation have focused on the temporal expression changes of intracellular signaling molecules and phenotypic markers that accompany differentiation, the complex patterns of extracellular molecule expression by differentiating pluripotent stem cells that can significantly influence cell phenotype(s) in an autocrine and/or juxtracrine manner remain less well defined
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
