FIGURE 1.

The pathology and timeline of chemotherapeutics-induced intestinal mucositis is primarily related to the effect of cytostatics on stem cells in the proliferation zone of the crypts: crypt base columnar (CBC) stem cells and transit amplifying daughter stem cells. Injury to the DNA of these cells causes apoptosis and initiates of a range of local tissue responses. These include generation of reactive oxygen species (ROS) and inflammation mediators, leading to further injury, inflammation, ulceration, villus and crypt atrophy, and the interstitial infiltration of luminal bacteria (commensal and pathogenic) and immune cells. After about 2 weeks the histology of the intestine is restored in humans (1 week in rodents). The green texts show potential targets for CIM intervention. The figure also shows the six different mature cell types of the intestines, the villi protrusions present in the small intestine, and the lymphatic, venous and arterial vessels. Artwork by Febe Jacobsson. EC = enterochromaffin.