Differential effects of a phorbol ester on carboxypeptidase E in cultured astrocytes and AtT-20 cells, a neuroendocrine cell line.

摘要: Cultured astrocytes have been shown to secrete various neuropeptides and the neuropeptide processing enzyme, carboxypeptidase E (CPE). The secretion of CPE enzymatic activity from has previously be increased approximately twofold by treatment with tetradecanoylphorbol 13-acetate (TPA), a phorbol ester. In this study, metabolic labeling [35S]Met was utilized examine effect TPA on biosynthesis protein in cultured AtT-20 cells, pituitary-derived cell line. Treatment 0.1 micrograms/ml for 24 h caused an 80% increase level radiolabeled both media indicating that synthesis stimulated TPA. cells also secreted more response TPA, but offset proportional decrease cellular CPE, not Northern blot analysis demonstrated elevated mRNA 50% cells. Quantitative situ hybridization studies TPA-induced expression largely due increases number expressing mRNA, although some brain regions average per These results suggest can induced express which is consistent role intercellular signaling.