The demand for stem cells is anticipated to continue to rise due to their expected ability to treat disease, use in novel diagnostic technologies, and for pharmaceutical screening. However, before these goals can be realized, a better understanding of the mechanisms regulating their fate is required. Stem cells integrate the many signals that surround them and execute cellular behaviors based on these inputs. These attributes can be harnessed and manipulated using synthetic biology to tightly control gene expression in dynamic patterns, in addition to programming cells to sense and record changes in their microenvironment. Upon successful completion, this work will enable a better understanding of the mechanisms involved in stem cell fate decisions that may eventually be exploited to direct differentiation.
Both intrinsic (transcription factor expression), as well as extrinsic (environmental) mechanisms are thought to be involved in the regulation of stem cell self-renewal, and their commitment to differentiate into more specialized cell types. This interplay between intrinsic and extrinsic cues in differentiation poses challenges to studying the mechanisms involved in their proliferation and terminal differentiation. These challenges can be addressed using genetic circuits. The completion of this research will produce tools to query the different timings, identities, and interactions of the internal and external signals of cell fate. This will be accomplished by developing strategies for probing stem cell differentiation using genetic circuits with the following objectives: (1) to expand the genetic toolbox for dynamically controlling gene expression in mammalian cells, (2) to assess changes in the extracellular microenvironment as stem cells differentiate by connecting genetic circuits to important receptors known to be involved in cell fate choices, and (3) to use these tools to probe stem cell differentiation. All of the results of this research will be made accessible to the research community. An additional important broad impact area of this research program is education and outreach of STEM fields at a variety of levels including elementary school, high school, and undergraduate students.
