Fig. 4
From: Signaling pathways in intestinal homeostasis and colorectal cancer: KRAS at centre stage
Illustration of intestinal homeostasis and implication of KRAS. a Intestinal stem cells (ISCs) are maintaining intestinal homeostasis through different signaling pathways including the RAS/MAPK. b Tight junctions and adherens junctions allows intestinal epithelial cells (IECs) to maintain a functional barrier integrity. c Epithelial hypoxia maintains IECs homeostasis (barrier function) as well as the environmental colon environment (microbiota and immune cells). d The commensal bacteria that colonize the colon are in symbiosis with the host to sustain intestinal balance. e Immune cells present in the colon contribute to the prevention of intestinal inflammation by maintaining intestinal homeostasis. f Signaling pathways that regulate proliferative cells metabolism (e.g. in ISCs) are essential to maintain self-renewal and proliferation rate of these ISCs, which maintains the integrity of the intestinal barrier