Presenter(s): Nicholas Jahahn − General Science
Faculty Mentor(s): Annie Zemper
Oral Session 4S
Research Area: Natural/Physical Science
Funding: National Institute of Diabetes and Digestive and Kidney Diseases, OURS program at the university of Oregon through NIH award
The intestine is a highly regenerative organ in humans and mice. Within the epithelium, structures called crypts contain epithelial stem cells that repopulate the intestinal mucosa. Lrig1 is an ErbB negative regulator that marks a population of stem cells in the base of the intestinal crypts. To study intestinal epithelium in a disease state, Dextran sodium sulfate (DSS) was used to induce ulcerative colitis in mice, characterized by inflammation of the distal colon epithelia. Here we examined the role of Lrig1 positive stem cells in colitis recovery. To accomplish this, we utilized transgenic mice that expressed Cre recombinase protein from the Lrig1 promoter and expressed YFP protein from the ROSA locus. Lineage tracing was carried out to observe what stem cells give rise to when the mouse is treated with DSS. Immunofluorescent analysis was conducted to visualize the localization of Lrig1 positive stem cells and their progeny in the wound healing process for comparison between homeostasis and different durations of recovery. It was observed that at both 36 and 48 hours after a weeklong assault of DSS there was a greater percentage of lineage traced cells found higher in the crypt compared to homeostatic conditions. We further observed that proliferation of the lineage traced cells followed the same trend. These results indicate that Lrig1 stem cells do actively participate in the recovery process. Where exactly the Lrig1 stem cells that participate in recovery originate from will be addressed with further lineage tracing closer to the time of cessation of DSS.