Growth-associated protein-43 expression in cocultures of dorsal root ganglion neurons and skeletal muscle cells with different neurotrophins.

ABSTRACT

INTRODUCTION: Both target skeletal muscle (SKM) cells and neurotrophins (NTs) are essential for the maintenance of neuronal function and nerve-muscle communication. The effects of different NTs and SKM cells on growth-associated protein-43 (GAP-43) expression in dorsal root ganglion (DRG) neurons have not been clarified. METHODS: The morphological relationship between DRG neurons and SKM cells in neuromuscular cocultures was observed by scanning electron microscopy. The levels of GAP-43 and its mRNA were determined after administration of different NTs. RESULTS: DRG neurons demonstrated dense neurite outgrowth in the presence of NTs. Distinct NTs promoted GAP-43 and its mRNA expression in neuromuscular cocultures of DRG neurons and SKM cells. CONCLUSIONS: These results offer new clues for a better understanding of the effects of distinct NTs on GAP-43 expression in DRG sensory neurons in the presence of target SKM cells and implicate NTs and target SKM cells in DRG neuronal regeneration.