Calcitonin gene-related peptide decreases expression of acetylcholinesterase in mammalian myotubes

Nerve-derived trophic factors are known to modulate expression of acetylcholinesterase (AChE) in skeletal muscle fibers, yet the precise identity of these factors remains elusive, In the present study, me treated mouse C2 myotubes with calcitonin gene-related peptide (CGRP). Compared to non-treated myotubes, cell-associated AChE activity levels ere decreased by similar to 60% after 48 h of treatment. A parallel reduction in AChE total protein levels was also observed as determined by Western blot analysis, The reduction in AChE. activity was due to a decrease in the levels of the GI molecular form and to an elimination of G(4). By contrast, levels of secreted AChE remained unchanged following CGRP treatment. Finally, the overall decrease in AChE activity was accompanied by a reduction in AChE transcripts which could not be attributed to changes in the transcriptional rate of the ACHE gene. (C) 1999 Federation of European Biochemical Societies.