Although advances in the study of multipotent adult stem cells have been made using murine models, significant translational limitations remain due to differences in murine and human physiology and disease states. For instance, at a recent meeting of the Intestinal Stem Cell Consortium, a team- science initiative established by the NIDDK and NIAID, identified the absence of a large animal model system as one of the most pressing impediments to translation of intestinal stem cell research from bench to bedside. A fundamental mechanism for repair of nearly all causes of gastrointestinal injury is reconstitution of architecture and function, driven by the proliferation of adult stem cells. Understanding the behavior of adult stem cells in the regenerative phase following acute or chronic insult is of intense interest to basic scientists and clinicians and provides a platform for discovery of stem cell-based therapies as well as novel pharmacologic agents and transplantation approaches that can promote reconstitution and repair. The goal of this proposal is to engineer transgenic pigs that will enable the study of adult stem cells, their progenitors and the stem-cell niche per se, using a large animal model having an anatomy, physiology, and ability to recapitulate human disease that overcomes the current limitations of rodent models. Successful completion of the proposed aims will generate a powerful animal model for study of translational aspects of adults stem cells of the gut, skin, liver, and kidney among others. This swine model will be used to answer questions regarding the role of stem cells in epithelial replacement during homeostasis and intestinal, hepatic, renal and skin diseases/injuries, including cancer, and regenerative responses resulting from radiation/chemotherapeutic or viral/ bacterial damage. Our approach is unique in that we propose to label a skin, intestine, liver, kidney and putative cancer stem cell marker and a key niche-supporting growth factor allowing us to better understand the relationship between stem cells and support cells. The proposed animal model will also have utility in multiple organ systems, and more generally in understanding the relationship between support cells and stem cells in a regenerative medicine context. As such this proposal affects multiple NIH centers.
The pig has a long history of use in biomedical research due to its physiological resemblance to humans. In the area of regenerative medicine, this physiological equivalence, combined with similarities in size, make pigs an excellent model in which to develop stem cell-based therapies. Recently, advances in meganucleases such as Zinc Finger Nucleases, Tal effector nucleases, and CRISPR-Cas have greatly enhanced the ability to carry complex genetic manipulations in this species. In this proposal we aim to develop a unique transgenic pig that will allow the tracking of stem cells and their support cells. This model will have great impact in a variety of stem cell fields including intestinal, liver, pancreatc, and skin repair and regeneration.