Intracellular calcium and arachidonic acid increase SNAP-25 expression in cultured rat hippocampal explants, but not in cultured rat cerebellar explants

Abstract

The effects of the increase of intracellular calcium, induced by membrane depolarization with 50 mM KCl, and arachidonic acid (AA) on the expression of 25-kD synaptosomal-associated protein (SNAP-25) were studied in cultured rat hippocampal and cerebellar explants, and PC12 rat pheochromocytoma cells, using immunoblot analysis. Incubation periods of 24 h and 48 h in 50 mM KCl increased SNAP-25 levels in hippocampal explants and PC12 cells, but not on cerebellar explants. Otherwise, a 24 h incubation with 10 mu M AA increased SNAP-25 expression only in hippocampal explants, although 100 ng/ml phorbol 12-myristate 13-acetate (PMA) did not have effect. These results indicate that intracellular calcium and AA can modulate the expression of SNAP-25, depending on the origin of the tissue.