Intestinal Stem Cells and Their Niche at Homeostasis and Under Stress

Abstract : The intestinal epithelium represents the most vigorously renewing adult tissue in mammals and intestinal stem cells (ISCs) fuel this process. Two main features characterized the ISCs: (i) their capacity of self-renewing and persisting over the entire lifetime of the organism; (ii) their multipotency, therefore allowing them to generate the multiple cell types present in the intestine. These features depend upon intrinsic program of the ISCs, but especially from signals that ISCs receive from their surrounding microenvironment: the niche. Three main actors have been described until now as being part of the ISC niche: Paneth cells, mesenchymal stromal cells, and the microbiota. This chapter highlights the recent advances in defining the niche of ISCs at homeostasis and under stress conditions.