The endocrine pancreas is both the substrate for fundamental questions in developmental biology as well asthe target of the disease diabetes mellitus, which affects millions of individuals worldwide. A detailed geneticand molecular understanding of pancreatic endocrine development will be essential if we are to manipulateislet cell fate and numbers in vivo. Our emerging understanding of pancreatic development is one in which,through interactions with surrounding mesenchyme, the initially unpatterned pancreatic epithelium issuccessively sub-divided into exocrine and endocrine compartments which subsequently differentiate, thelatter containing the |3eta cells that produce insulin. Among the factors that dictate islet cell specification aremany genes whose identities are now known. In fact, it is now possible to order these genes into a firstorder genetic regulatory network in terms of order of gene action, expression and functional interdependencies,and hierarchical relationships. This grant therefore poses the question: Do we already knowenough, and can we sufficiently augment that knowledge, to begin to use this information to systematicallyengineer islets and islet cells in vitro?To accomplish this ambitious goal, we will undertake three Specific Aims that are highly integrated withmultiple components of SysCODE.
In Aim 1, we will generate complete gene lists for key early states in thedeveloping endocrine pancreas. An initial effort in this area has already been accomplished (Gu et al.,Development 131, 165-79, 2004). We will now augment this information with data from additionaldevelopmental stages, selected mutant states and first-generation proteomic analyses.
In Aim 2, inconjunction with the SysCODE Computational Team, we will develop methodology to order these genes andselected proteins into a definitive gene regulatory network (CRN) in a format that is useful to both biologistsand tissue engineers. Lastly, in Aim 3 we will collaborate with the SysCODE Tissue Engineering Team toimplement a stem cell based, engineered model of pancreatic islet development and we will use the GRNsgenerated in Aim 2 to optimize pancreatic endocrine fate specification. In the out years of the grant, we willtransplant the engineered islets into diabetic mice and assess their physiological function. Collectively, theseefforts, in conjunction with the rest of SysCODE, will establish a transforming paradigm for regenerativemedicine.
| Hrvatin, Sinisa; O'Donnell, Charles W; Deng, Francis et al. (2014) Differentiated human stem cells resemble fetal, not adult, ? cells. Proc Natl Acad Sci U S A 111:3038-43 |
| Hrvatin, SiniĊĦa; Deng, Francis; O'Donnell, Charles W et al. (2014) MARIS: method for analyzing RNA following intracellular sorting. PLoS One 9:e89459 |
| Sherwood, Richard I; Maehr, Rene; Mazzoni, Esteban O et al. (2011) Wnt signaling specifies and patterns intestinal endoderm. Mech Dev 128:387-400 |
| Sherwood, Richard I; Chen, Tzong-Yang Albert; Melton, Douglas A (2009) Transcriptional dynamics of endodermal organ formation. Dev Dyn 238:29-42 |
