Embryonic stem cells (ESCs) hold tremendous promise in developmental biology, tissue engineering, and regenerative medicine applications because of their unique combination of pluripotency and limitless proliferation potential. To translate the possibilities of these cells into scientific and medical advances, one must understand how they integrate environmental stimuli, including soluble chemical factors, extracellular matrix proteins, cell-cell interactions, and biophysical forces, in their self-renewal and differentiation decisions. This project will specifically address how ESCs spatially and temporally respond to mechanical cues in the microenvironment in the context of a chemically defined culture system. Experiments will ascertain how biophysical stimuli synergize with biochemical cues to determine whether an ESC self-renews or differentiates. In addition, the predication that both physical and chemical signals influence lineage-specific differentiation of ESCs to cardiac myocytes will be tested.
The approach to be used involves an iterative loop of three integrated activities. First, the Principal Investigators' (PIs') expertise in materials and interfaces will be used to design and characterize novel culture systems that permit application of spatially and temporally defined mechanical stresses to ESC colonies. Next, the PIs' experience in cell and molecular biology will allow one to elucidate signal transduction pathways stimulated or repressed by mechanical strain and to determine how mechanical signals interact with biochemical regulators of ESC growth and differentiation. Finally, the PIs' expertise in cellular and molecular modeling will be used to construct mathematical models describing the complexity of signals and pathways regulating ESC differentiation. The models will predict optimal presentation of microenvironmental cues to cells to promote self-renewal or differentiation; then, these predictions will be tested experimentally. The data from these experiments will provide additional information that will promote further model refinement.
The scientific understanding of the relationships between environmental signals regulating ESC research gained from this project may provide a rational basis for design of ESC culture systems that will facilitate their use in research and clinical settings. The project will also support a novel public outreach plan, consisting of forums discussing the technical aspects of stem cell biology and engineering as well as societal impacts of ESC research. Educational initiatives to recruit high school and undergraduate students, especially those from underrepresented groups, into stem cell engineering or other scientific disciplines will also be enabled by this project. Finally, this project will support construction and dissemination of stem cell engineering educational materials by the PIs.
