Purpose: To investigate the effects of Schwann cell-derived neurotrophic activity (SCNA) on cultured retinal ganglion cells (RGC) survive and the expression of growth associated protein 43 (GAP43) in normal and gas-deprived environment.
Methods: Schwann cells of new born SD rat were cultured, and remaded it into solutions containing different concentrations of SCNA. Then these solutions were added to the primarily cultured retinal cells, the activity of SCNA was determined by MTT method. The fluro-gold retrolabelled retina cells of 3d new born rats were cultured and plated on 24 well culture plate. At the 2rd day of culture, 300 mg/L SCNA were added into the medium of SCNA group. At the 5th day, liquid paraffin was added on the surface of medium of air deprived groups to lead an air deprived injury. Cultured for 12h, the liquid paraffin was discarded off, and then we observed the morphology and counted the fluro-gold labeled RGC. The effects of SCNA on the expression of GAP43 in cultured retinal cells were identified by Western Blot.
Result: SCNA could promote the survival of RGC in a protein concentration-dependent manner. Added SCNA to the medium, the retinal cells grown much better and had less floating dead cells. The number of RGC was also significantly more than the control (F = 62.89, P < 0.01). The cells of air deprived group had showed swelling change. But the cells of group with SCNA are less affected and the number of RGCs is significantly different from the control (F = 49.27, P < 0.01). The expression of GAP43 in normal and air deprived groups with SCNA were up-regulated.
Conclusion: SCNA has significantly neurotrophic effect on cultured RGC and increases the expression of GAP43. Added SCNA to the medium could reduce the injury of air deprived and promote RGC survival rate in this kind of injury environment.