Neurotrophic Effects of Schwann Cell Secretions from Wallerian Degenerating Facial Nerves on Neonatal Rats Facial Motoneurons in vitro

다국어 초록 (Multilingual Abstract)

Regeneration and functional recovery of facial nerves after injury are still far from satisfaction. Studies on whether Schwann cells of injured facial nerves could secrete neurotrophic factors to promote nerve regeneration are rare, and that is the pbjective of this study. Schwann cells from Wallerian degenerating segments of rats facial nerves were isolated and cultured in conditioned culture medium, collected, concentrated and fractionated by ultra-filtration. The neurotrophic bioactivity of the soluble secretions from cultured Schwann cells were examined on an established neuron culture model. Dil fluorescence labeling facial motoneurons from neonatal rats, MTT assay, and image analysis for survival of facial motoneurons were used. The results show that facial motoneuron survival activity in Schwann cell culture medium containing a molecular weight larger than 30 kDa component, was significantly higher than in medium with and without serum (p<0.05 and p<0.01 respectively). The effect could be extinguished by either boiling or trypsinizing. At the 2nd, 4th and 7th days after conditioned culture, mean perikaryon area and neurite length of facial motoneurons in a medium containing molecular weight larger than 30kDa component, were significantly larger than in serum containing medium. The results show that Schwann cells from Wallerian degenerating facial nerves in serum-free and neurite re-growth of facial motoneurons in vitro. The results also suggest that the neurotrophic effect might be derived from protein(s) or peptide(s) with molecular weight larger than 30 kDa component of the soluble secretions. It may be potent for functional repair of facial verve and other neural disorders.