Replenishment of intestinal stem cells during the repair of radiation-induced intestinal injury / 中国组织工程研究

ABSTRACT

BACKGROUND:Radiation-induced intestinal injury causes a sharp reduction in the number of intestinal stem cells (ISCs) and their dysfunction.This brings great challenges in the repair of injured intestinal epithelium.Prompting restoration of the number and function of ISCs is a highlight of current research in the treatment of radiation-induced intestinal injury as well as in the repair of injured intestinal epithelium.OBJECTIVE:To review the latest progress in the pathway and mechanism of ISCs replenishment after radiation-induced intestinal injury.METHODS:The first author searched the CNKI,Wanfang and PubMed databases using the keywords of “intestinal stem cell,radiation-induced intestinal injury” in Chinese and English,respectively,to retrieve relevant articles published from January 2010 to June 2016.Then we generalized and summarized the results of these articles.RESULTS AND CONCLUSION:The fate of ISCs is regulated by various signal pathways,mainly including Wnt/β-catenin,BMP,Notch and EGF pathways.Early secretory progenitors (ESPs) are relatively quiescent during homeostasis,and insensitive to radiation injury;moreover,the ESPs can convert to ISCs under certain conditions.So,they are desired source of “reserve stem cells”.Stem cell niche plays an important role in reverse differentiation from ESPs to ISCs,but the exact regulatory mechanism remains largely unknown.Investigation on the above mechanism is of important scientific significance for deeply understanding the restoration process after radiation-induced intestinal injury and thus actively regulating intestinal injury repair.