Epithelial/Endothelial Cell Biology & Mucosal Injury and Repair

1. The gastrointestinal mucosa is constantly charged with the dual purposes of absorbing nutrients and maintaining a barrier between the luminal contents and the blood stream. We have a long-standing interest in the cellular mechanisms of epithelial cells to mucosal injury. One model that we have investigated thoroughly is luminal lipid-induced postprandial injury. Particular emphasis was placed on the role of goblet cells and their secretory products in the protection of the intestine following mucosal injury. The model currently in use is intestinal anaphylaxis induced by luminal exposure to ovalbumin in sensitized rats. The acute injury and subsequent repair is followed by a chronic systemic injury involving the upregulation of leukocyte/endothelial cell adhesion molecules and the dissemination of the injury to distant organs like the lung.
2. A second project involves the progression of mucosal injury and epithelial responses in severe combined immunodeficient mice that have been reconstituted with a single subpopulation of T lymphocytes. The animals develop chronic colitis in 6-8 weeks, with most of the symptoms of human inflammatory bowel disease. Our interest is in the mechanisms of mucosal injury and the mucosal response to the altered interstitial immune cell populations.
3. A third project is collaborative and deals with the chemoprevention of polyp recurrence in humans. Our role in the project is to determine the efficacy of cycloxygenase inhibitors in the altered phenotypic expression of precancerous human mucosal epithelial cells.

1. Microscopy/Imaging using light microscopy, laser scanning confocal microscopy, transmission and scanning electron microscopy
2. Immunostaining at the light and electron microscopic level