Analysis of isoproterenol-induced changes in parotid gland gene expression

Abstract

Parotid gland acinar cells undergo marked hypertrophy and hyperplasia upon systemic exposure to the β-adrenergic agonist, isoproterenol. This glandular enlargement is accompanied by substantial cellular changes including DNA synthesis, an increase in glandular protein synthesis, and differential changes in RNA transcription. To gain a more detailed understanding of the underlying changes induced by isoproterenol, we have examined the parotid gland gene expression profile of mice up to 24 h post-isoproterenol injection using high-density oligonucleotide arrays. Depending upon the exposure time, between 22 and 48 of the ∼6,500 mouse genes and expressed sequence tags (ESTs) analyzed displayed significant changes in expression patterns. Genes that were previously shown to be repressed (α-amylase) or activated (proline-rich proteins) following isoproterenol exposure were found to be similarly affected in this experiment, validating this technique. This study demonstrates that the oligonucleotide array technology is a useful tool for examining isoproterenol-induced salivary gland gene expression changes. Using this as a starting point, we can begin to dissect the specific pathways involved in mediating isoproterenol action within the parotid gland.