Related Experiment Videos
Apoptosis of crypt epithelial cells in ulcerative colitis
M Iwamoto1, T Koji, K Makiyama
1Department of Medicine II, Nagasaki University School of Medicine, Japan.
The Journal of Pathology
|October 1, 1996
Summary
Ulcerative colitis (UC) involves epithelial cell loss through apoptosis, primarily in crypts. The Fas/Fas-ligand pathway mediates this programmed cell death in active UC patients.
Area of Science:
- Gastroenterology
- Cell Biology
- Immunology
Background:
- Apoptotic bodies are observed in the colons of ulcerative colitis (UC) patients.
- The precise mechanism and extent of epithelial cell loss in UC require further investigation.
Purpose of the Study:
- To investigate the extent and mechanism of apoptosis in the colons of active UC patients.
- To compare apoptosis markers in involved and uninvolved UC colonic tissues versus normal colonic tissue.
Main Methods:
- Analysis of colonic biopsies from UC patients and controls using TUNEL assay for DNA breaks.
- Immunohistochemistry for Fas and Fas ligand (Fas-L) expression.
- Electron microscopy for apoptotic features and DNA laddering analysis.
Main Results:
- Apoptosis marker-positive cells were found in the luminal epithelium of normal colon and in crypts and luminal epithelium of active UC colons.
- DNA extracted from active UC colons showed characteristic laddering.
- Fas and Fas-L were localized in apoptotic cells, suggesting their involvement.
Conclusions:
- Epithelial cell loss in active UC predominantly occurs via apoptosis within the crypts of affected and adjacent uninvolved areas.
- The Fas/Fas-L interaction is identified as a key mediator of apoptosis in ulcerative colitis.