Gene expression profiling and molecular aspects in peripheral nerve regeneration

Regeneration of the peripheral nervous system after injury depends on a complex sequence of histopathological reactions that comprise a highly reproducible sequence of degenerative reactions, termed Wallerian degeneration. During this period a remodelling of the distal nerve stump prepares a microenvironment that permits successful regrowth of nerve fibers from the proximal nerve fragment. This stereotypical sequence of reactions is reflected by a differential and coordinate expression of genes with specific functions in the process of regeneration. This review will summarize cellular and molecular reactions that contribute to peripheral nerve regeneration including data of a pilot study in which membrane based cDNA array expression technology was applied. We examined the expression of 588 annotated genes in response to a crush lesion of rat sciatic nerves. Approximately 40 % of the genes spotted onto the array filters showed expression significantly above background and 55 of these detected genes represented differential expression profiles after nerve lesion. This approach revealed to be suitable for systematic screening of regeneration associated genes.