Expression of acetylcholine nicotinic receptor a7 in rat Schwann cells: implication in nerve regeneration

Expression of acetylcholine nicotinic receptor a7 in rat Schwann cells: implication in nerve regeneration Alessandro Matera1, R. Piovesana1, M. Taggi2, R. Canipari2, C. Dallanoce3, C. Fabrizi2, A. M.Tata1 1Dip. Biologia e Biotecnologie Charles Darwin, Sapienza , Università di Roma; 2Dipartimento SAIMLAL - Sapienza, Università di Roma; 3Dip. Di Scienze Farmaceutiche, Sezione di Chimica Farmaceutica, Pietro Pratesi, Università di Milano Peripheral Nervous System is able to regenerate. During regeneration, Schwann cells (SCs) assume a phenotype known as Repair Schwann Cells, relevant for promoting an anti-inflammatory environment and axonal regeneration. SCs are cholinoceptive and express muscarinic receptors. Recently, we have characterized the expression of α7 nicotinic receptor. Normally this receptor is fainlty expressed in SCs, as observed both in vivo and in vitro. Its expression significantly increased after nerve injury. In fact in presence of Bradykinin (Bk), a neuropeptide known for its pro-inflammatory effects, the expression of α7 significantly increased both in sciatic nerve fibers and in SCs in vitro. The treatment of cultured SCs with α7 selective agonist (R)-ICH3, after BK treatment, counteracts inflammatory environment in terms of cytokines, growth factors and proteases production, causing a decreased expression of TNFα and modulating tPA, uPA, and MMPs involved in the migration processes and growth factor production. These results suggest that α7 nicotinic receptor may be essential in the establishment of a microenvironment improving peripheral nerve regeneration.