Abstract:  Objective To investigate the neuroprotective effects of small interfering RNA (siRNA) on retinal ganglion cells (RGC) in optic nerve crush model rats. Design Experimental study. Participants fifty-four SD rats. Methods fifty-four SD rats were divided into 3 groups, group A, B, and C, 18 rats per group. The right eyes of all rats were crushed by micro-clipping with 40 g power for 60 s, the left eyes were not crushed as the controls. A and B group was given siRNA 10 μg/per eye and siRNA 20 μg/per eye, the group C was given normal saline intravitreal injectionon immediately after optic nerve crush. The experiment lasted for 14 days. Six rats in each group were retrograde labeled by injection of 3% fluorogold (FG) into both side of superior colliculus at 10 days after the crush. At the 14 day, the rats were sacrificed and stretched preparation of retina, RGCs were photographed and counted with mask method. The survival percentage of RGCs = RGCs density in right eye / RGCs density in left eye. Further the western blot was used to exam the expression level of caspase-3 protein in retinal tissue. Main Outcome Measures The survival percentage of RGC, the expression level of caspase-3 protein. Results The average survival percentage of RGCs in A, B and C group was 53.63%±7.35%, 57.86%±6.00%, 45.00%±4.37% respectively (F=7.11, P=0.029). A significant difference was found between group A and C(P=0.025), between group B and C(P=0.002) as well. The difference between group A and B was not significant (P=0.24). The expression level of caspase-3 protein in the A, B, C groups in the retinal tissue was 0.20±0.02, 0.19±0.02, 0.24±0.03 (F=9.73, P =0.02). A significant difference was found between group A and C(P=0.005), between group B and C(P=0.001) as well. The difference between group A and B was not significant(P=0.418). Conclusion siRNA shows the neuroprotective effects on RGCs in optic nerve crush model rats.

Key words: text-indent: 0px, display: inline !important, font: medium Simsun, white-space: normal, float: none, letter-spacing: normal, color: rgb(0,0,0), word-spacing: 0px, -webkit-text-stroke-width: 0px">neuroprotection, small interfering RNA, retinal ganglion cells