[Immortalized adult rodent Schwann cells as useful tools for the study of peripheral nerve regeneration]

We have established spontaneously immortalized Schwann cell lines from adult ICR mice [IMS32] and Fischer344 rats [IFRS1]. IMS32 cells display distinct Schwann cell phenotypes such as a spindle-shaped morphology and the expression of glial cell markers (e.g. S100, glial fibrillary acidic protein (GFAP), p75 low-affinity neurotrophin receptor (p75(NTR))) and neurotrophic factors. In addition, conditioned medium obtained from IMS32 cells enhances neurite elongation of PC12 cells and mouse dorsal root ganglion (DRG) neurons. IMS32 cells have been utilized to investigate the action mechanisms of various molecules that accelerate peripheral nerve regeneration (e.g. ciliary neurotrophic factor, sonic hedgehog, galectin-1). Like IMS32 cells, IFRS1 cells retain the characteristic features of mature Schwann cells as described above. Furthermore, IFRS1 cells have been shown to myelinate neurites in coculture with adult rat DRG neurons and PC12 cells. Our current investigation with IFRS1 cells focuses on the molecular mechanisms of myelination-inducible factors, such as soluble neuregulin-1 type III and exendin-4. These Schwann cell lines can be valuable tools for exploring neuron-Schwann cell interactions, pathobiology of axonal degeneration and regeneration in the peripheral nervous system, and novel therapeutic approaches against neurological disorders in patients with relevant diseases.