Expression and localization of prominin-1 in isoproterenol-treated rat parotid gland

Prominin-1 (CD133) is a pentaspan cholesterolbinding membrane glycoprotein. Chronic treatment with isoproterenol, a beta-receptor agonist, induces several dramatic effects on salivary glands, such as enhanced DNA synthesis and proliferation of salivary acinar cells. In addition, the biosynthetic pathways of membrane lipids may be altered by the isoproterenol stimulation. The purpose of this study was to investigate the effect of isoproterenol administration on prominin-1 expression profiles in rat parotid gland by means of PCR and immunohistochemistry. Rats were chronically treated with the B-adrenergic agonist for 1, 3, and 7 days. Our results showed that isoproterenol-treatment caused a down-regulation of prominin-1 on day 3 and 7 of treatment, as well as a differential immunostaining distribution pattern. This study suggests that isoproterenol-treatment may represent a useful tool to explore the molecular mechanisms involved in the synthesis and release of prominin-1. Such efforts could contribute to the development of diagnostic tools based on the detection of prominin-1 in biological fluids, such as saliva.