Hillary Hansen, University of Utah
Life Sciences
Type 1 diabetes is an autoimmune disease where pancreatic β-cells are destroyed, resulting in insulin deficiency. Generating new β-cells from stem cells for treating diabetes will benefit from understanding their development in vivo. Pancreatic β-cells, along with all other pancreatic lineages arise from multipotent pancreatic progenitor cells (MPCs). Previous studies demonstrate that the structural and signaling protein β-catenin is required for the development of the exocrine acinar lineage. β-cells still differentiate in the absence of β-catenin, however, β-cell mass is dependent upon β-catenin. We determined that this dependency reflects a role for β-catenin in the maintenance of MPC patterning as well as for expansion of the progenitor pool. Whether our observed effects are due to the signaling or structural function of β-catenin remains unknown, and is the focus of this research. Using mouse genetics we are able to separate the structural and signaling functions of β-catenin. Eliminating both functions in PBKO (full knockout) mice produces decreased β-cell mass and irregular patterning. Decreased β-cell mass is also observed in PBsKO (signaling deficient) mice, though patterning remains unaffected. This suggests that pancreas growth is dependent upon canonical Wnt/β-catenin signaling, and that maintaining progenitor identity requires the structural role of β-catenin. Elucidating distinct roles for β-catenin could be used to drive stem cell-derived MPCs to expand and differentiate to the desired pancreatic cell fate.