Analysis of Stem Cells in Intestinal Inflammatory Pathologies

MARIA BELÉN POLO; EMANUEL BARBIERA ROMERO; CECILIA MUGLIA; GUILLERMO DOCENA

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias; 2022

Intestinal epithelial cells (IECs) are key elements of the intestinal epithelial compartment. It is implicated in cross-talk with the microbiota and the underlying immune cells and in barrier integrity. A continuous replacement of differentiated cells maintains the homeostasis of the intestinal epithelium through the replication of stem cells (ISCs) located within the crypts. However, in different inflammatory settings, the renewal of epithelial cells may be altered, contributing to different chronic pathologies. This work aimed to identify and quantify human intestinal stem cell populations in different pathological conditions.We quantified stem cells in intestinal biopsies (23) and surgical pieces (8) of inflamed and surrounding tissue of adult patients with colorectal cancer (CCR), inflammatory bowel diseases (IBD) (19), and healthy controls (HC) (8), and from colorectal polyps of pediatric patients sensitized to cow´s milk protein (11) and biopsies surrounding the polyps (3). Stem cells were identified and quantified as LGR5+ cells by flow cytometry and confocal microscopy.Our results showed a higher frequency of LGR5+ cells in inflamed IBD tissue compared to non- inflamed IBD tissue and gut from HC (p=0,005). In contrast, we found a smaller fraction of LGR5+ stem cells in polyps’ samples compared to its control surrounding biopsies (p=0,03). Immunofluorescence microscopy revealed the presence of LGR5+ cells within the epithelial compartment, and mainly located in the crypts.In conclusion, we found an expansion of colonic stem cells in different pathologies and inflammatory conditions, being more expanded in inflamed tissues. Further analysis, including functional and next-generation sequencing assays, is in progress to get more insights into the role of these cells in the different inflammatory pathologies.