Dissecting The Cellular Responses Of Immune Cells And Lgr5+ Stem Cells In The Inflamed Mouse Colon With The Rnascope In Situ Hybridization Technology

Due to its exposure to a harsh luminal environment, the intestinal epithelium has a remarkably fast turnover rate that is facilitated by a resident intestinal stem cell (ISC) population present at the base of the intestinal crypt. These ISCs, marked by the GPCR Lgr5, allow the intestinal epithelium to adapt to different types of damage, such as inflammation. Chronic intestinal inflammation is a hallmark of the inflammatory bowel diseases (IBD) yet the interplay between inflammatory immune cells and ISCs remains to be elucidated. Therefore, we utilized the single-molecule RNA in situ hybridization (ISH) technology RNAscope to visualize the expression of multiple immune and ISC markers within the inflamed intestinal tissue environment. To interrogate the expression pattern of inflammatory immune cell and ISC markers within the intestinal crypt, we performed the assay on colons from either control or TNBS-treated mice. We visualized the location of each intestinal cell population, including the resident Lgr5+ ISC population, within the crypt. The impact of inflammation on the Lgr5+ ISC population, as well as the Wnt/β-catenin pathway, was also examined. Using a multiplex assay, we assessed infiltration of regulatory T cells and Th17 cells in the inflamed region. Lastly, we examined the expression of several receptor-ligand pairs for cytokines and ISC markers. Taken together, these results demonstrate the ability of the RNAscope assay to visualize the ISCs within the morphological context of the intestinal crypt and in relationship to inflammatory immune cells. This work may help understand mechanisms behind the pathogenesis of IBD and other inflammatory diseases and also aid in the development of potential therapies.