Axon-Schwann cell interactions regulate the expression of fibroblast growth factor-5 (FGF-5)

We screened for genes whose expression is significantly up- or downregulate d during Wallerian degeneration in adult rat sciatic nerve with cDNA arrays . Fibroblast growth factor-5 (FGF-5) mRNA seemed to be induced. This was co nfirmed by northern blotting and in situ hybridization, as well as Western blotting for FGF-5 in axotomized nerve. Axon-Schwann cell interactions decr eased the steady-state level of FGF-5 mRNA in regenerating sciatic nerves, and forskolin diminished its expression in cultured Schwann cells. We concl ude that denervated Schwann cells synthesize FGF-5, which is a secreted, ne uronotrophic member of the FGF family. (C) 2001 Wiley-Liss, Inc.