To investigate the relationship between the thickness of tongue fur, apoptosis of the tongue fur epithelial cells and expressions of apoptosis-related genes in diseases of the digestive system, apoptosis-related genes TGF-β3, fas mRNA and protein products were detected with terminal deoxynucleotidyl transferase-mediated deoxyurine triphosphate (d-UTP) nick-end labeling(TUNEL) technique, in situ hybridization, immunohistochemical methods, and image analysis technique, respectively. Results indicated that compared with the normal tongue fur, over-expression of fas gene was found in the peeling fur with an increase in cell apoptosis, while a low-expression of TGF-β3 in the thick fur with a decrease in cell apoptosis. The changes in expression levels of fas and TGF-β3 genes, apoptosis-promoting genes in the tongue fur epithelial cells, had a similar tendency of cell apoptosis level. It is concluded that the changes in expression levels of fas and TGF-β3 are possibly important reasons influencing apoptosis of epithelial cells of tongue fur and leading to changes in thickness of the tongue fur.
