Enterocyte progenitors can dedifferentiate to replace lost Lgr5+ intestinal stem cells revealing that many different progenitor populations can regain stemness
The epithelium lining the gastrointestinal tract serves many functions, including aiding in digestion, nutrient absorption, barrier function, and immunity. In the small intestine, the intestinal epithelium is comprised of repeating crypt-villus units which undergo constant renewal to maintain intestinal homeostasis and tissue integrity (1). Multipotent intestinal stem cells (ISCs) located in the base of the crypt are responsible for constant renewal and rapid replenishment of cells lining the crypt-villus axis. ISCs give rise to rapidly proliferating transit-amplifying (TA) cell population which, as they exit crypt, differentiate into the four major mature cell types: enteroendocrine cells, goblet cells, and Paneth cells belong to the secretory lineage, while enterocytes comprise the absorptive lineage. Although it is agreed upon that each crypt contains ISCs, the exact identity of the stem cell population has been debated for many years (2,3).