Current advances in renewal mechanisms of intestinal epithelial cells along the crypt-villus axis

The small intestine is not only an organ for food digestion and nutrient absorption but also an integral part of the immune and endocrine systems. Differentiation of enterocytes plays an important role in the damage repair mechanism after immune response elicitation by the intestine, for restoring the intestinal barrier function and homeostasis. Recently, research related to self-renewal, differentiation, and regulation of the intestinal epithelial crypt stem cells has been developing rapidly. In this review, we attempt to sum up recent studies related to the expression pattern of genes and proteins along the crypt-villus axis, and the effect of signaling pathways, transcription factors, and epigenetic modifications on the differentiation of crypt stem cells. We also examine the mechanisms by which nutritional factors influence the differentiation and damage repair processes of the intestinal epithelial cells. This review could provide valuable theoretical framework in nutritional and pharmacological aspects and guidance for intervention and treatment of intestinal damage and related diseases.