Effect of transverse quantitative tractive injury on autophagy level of retinal ganglion cells in rats

Abstract

AIM: To investigate the effect of different degrees of traction power on the survival rate of retinal ganglion cells(RGCs)and nerve conduction in rats, and to discuss the effect of autophagy level of RGCs on the above parameters.METHODS: A total of 30 healthy male Sprague-Dawley(SD)rats were randomly divided into empty group, sham-operation group, 0.15N, 0.3N and 0.6N group, with 6 rats in each group.Modeling group was performed the transverse quantitative traction to make a rat model of optic nerve injury. In addition, rats in empty group were not operated and rats in sham-operation group only got optic nerve exposed. Flash visual evoked potentials(f-VEP)were performed respectively on 1 and 3d after modeling.The survival of retinal ganglion cells was observed by Brn-3a staining at 3d after modeling, autophagy bodies were observed by transmission electron microscope, and the expression level of LC3B II/I protein was detected by Western blotting.RESULTS: Compared with sham-operation group, the f-VEP P2 peak was significantly delayed and the amplitude reduced at 3d after modeling. In addition, the survival rate of RGCs was decreased, and the expression level of LC3B II/I protein were decreased. Autophagy bodies were observed in the retinal tissue of rats in all groups.CONCLUSION: Optic nerve traction reduced early retinal autophagy level, death of RGCs and corresponding nerve conduction dysfunction in rats,and different traction caused different degrees of injury. In addition,there was a correlation between the autophagy level and the survival of RGCs.

Keywords

• autophagy
• traumatic optic neuropathy
• retinal ganglion cells
• transverse quantitative traction method
• flash visual evoked potential