The Role ofPaneth Cells in the Pathogenesis of Inflammatory Bowel Disease

摘要

Introduction: Paneth cells are one of four epithelial cell types produce by intestinal epithelial stem cells (1) and are located throughout the length of the small intestine of both mice and man. The additional location for Paneth cells is the proximal human colon that occurs only as a metaplastic response to an inflammation. Paneth cells co-mingle with multipotent stem in the base of frequent epithelial invaginations called crypts of Lieberktthn. There is recent evidence that this interaction supports stem cells (2). Only a few dozen Paneth cells populate each crypt. However, because of the substantial number of small intestinal crypts in a mouse (-1.1 million), the overall number of Paneth cells are > 20 million. The localization of Paneth cells within the small intestinal epithelium is distinct in comparison to the other three differentiated lineages that are produced by stem cells: absorptive enterocytes, mucus producing goblet cells and hormone secreting enteroendocrine cells. These three lineages emerge from crypts and migrate onto villi which are evaginations of the mucosal surface into the lumen of the intestine. Each crypt supplies cells to multiple surrounding villi (each villus is supplied by 6-8 surrounding crypts). The lifespan of villus epithelial cells is much shorter (on the order of 3-5 days) than Paneth cells that migrate to the base of crypts where they are much longer lived (>30 days).