Host: The Japanese Pharmacological Society
Name : The 96th Annual Meeting of the Japanese Pharmacological Society
Number : 96
Location : [in Japanese]
Date : November 30, 2022 - December 03, 2022
Epithelial cells of exocrine glands responsible for saliva and tear secretion bear cell polarity. Cdc42, essential for the polarity of epithelial cells, is required for the formation and maintenance of luminal structures which is important site for the secretion. However, it is still unclear whether Cdc42 plays the identical role in different epithelial tissues in vivo. In this study, we generated exocrine epithelial cell-specific Cdc42 conditional knockout (KO) mice and analyzed the difference of Cdc42 roles between salivary glands and lacrimal glands.
Morphological analysis showed that luminal structures changed to thick, short, bulging structures in the both Cdc42 KO glands. Since these glands weight decreased, we analyzed inflammation with HE staining and apoptotic cell death with TUNEL staining. Both glands showed no inflammation nevertheless TUNEL (+) cells increased, suggesting disrupted cell polarity. In contrast, pilocarpine-stimulated saliva secretion decreased while tear secretion increased. Moreover, protein expression of AQP5, essential for exocrine fluid, also decreased in the salivary glands but conversely increased in lacrimal glands.
These findings suggest that Cdc42 in salivary glands and lacrimal glands plays an identical role in epithelial cell polarity formation but an opposite role in the secretory mechanism.
