[In vivo characterization of sonic hedgehog in the peripheral nerve regeneration]

A large number of genes regulate the process of regeneration after the nerve injury. Facial nerve axotomy of rats provides us with a useful model in which to study the molecular and cellular mechanisms of peripheral nerve regeneration. We performed the subtracted library screening of the facial nucleus after the facial nerve axotomy. We identified the sonic hedgehog (Shh) as a candidate molecule that regulates regeneration of injured neurons. By making adenoviral vector that transfers Shh, we found that the motor neuron survival was significantly promoted for 3-5 days after neonate rat injury. Furthermore, the continuous application of cyclopamin, which is a signal inhibitor of Smoothened, to the injured site, motor neuron death was induced in the adult rats after axotomy. These results indicate that Shh may play a regulatory role in the regeneration after nerve injury.