Regulation of A2aadenosine receptor mRNA expression by agonists and forskolin in PC12 cells

Abstract

Modulation of A2a adenosine receptor (A2aAR) expression by adenosine agonists was studied in cultured PC12 cell lines. Exposure of A2aAR agonists such as 5'-N-ethylcarboxamidoadenosine (NECA) or CGS-21680 caused a transient increase followed by a decrease of A2aAR mRNA in PC12 cells in 10 h. This was followed by a gradual recovery to control levels by approximately 24 h. These changes were blocked by an adenosine receptor antagonist, xanthine amine congener. Forskolin also induced similar changes in the level of A2aAR mRNA. In addition, A2aAR numbers of PC12 cell membranes were significantly decreased during the NECA-exposure. These results suggest that A2aAR gene expression in PC12 cells is regulated by activation of A2aAR via a mechanism involving the second messenger, cAMP.