Extension of optic nerve fibers on genetically modified cells producing brain-derived neurotrophic factor.

Since brain-derived neurotrophic factor (BDNF) promotes the survival of retinal ganglion cells (RGCs), we transfected a rat BDNF cDNA into rat fibroblasts, and retinal fragments of rat embryos were cultured on cell monolayers of these cells. Retinal fragments showed enhanced neurite extension on BDNF-transfected cells compared with that on control cells. The degree of the neurite extension, however, decreased depending upon the embryonic stages. These results suggest that fibroblasts genetically modified to produce BDNF might be a promoter of neurite extension by RGCs, but this does not apply to the RGCs of late embryonic stages.