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

Nerve-derived trophic factors are known to modulate expression of acetylcho linesterase (AChE) in skeletal muscle fibers, yet the precise identity of t hese factors remains elusive, In the present study, me treated mouse C2 myo tubes 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 lev els 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 re mained unchanged following CGRP treatment. Finally, the overall decrease in AChE activity was accompanied by a reduction in AChE transcripts which cou ld not be attributed to changes in the transcriptional rate of the ACHE gen e. (C) 1999 Federation of European Biochemical Societies.