Abstract
Purpose :
Retinal ischemia-reperfusion (RIR) injury causes neuronal degeneration and initiates various optic nerve diseases. This study investigated the synergistic neuroprotective mechanisms of rasagiline and idebenone against RIR injury.
Methods :
Acute ocular hypertension was induced as the RIR model. A combination of rasagiline and idebenone was administered intraperitoneally immediately after establishment of the RIR. Apoptosis of retinal ganglion cells was evaluated by TUNEL assay. Western blot and qPCR were performed for mechanistic analyses.
Results :
Treatment with the combination of the two drugs resulted in a significant restoration of retinal thickness and retinal ganglion cells （P＜0.001, n= 6/group）. Apoptosis of cells in ganglion cell layers was also ameliorated （P＜0.001, n= 6/group）, suggesting that the effect of the two drugs was synergistic and the expression of brain-derived neurotrophic factor increased. Furthermore, rasagiline and idebenone induced the expression of Lin28B and Lin28A （P＜0.001, n= 6/group）, respectively, which resulted in a reduced expression of microRNAs in the let-7 family and an increased protein output of Dicer （P＜0.001, n= 6/group）. The data obtained from gene overexpression and knockdown experiments indicated that let-7 and Dicer were necessary for the synergistic neuroprotective effect of the two drugs.
Conclusions :
Our findings suggested that combination therapy with rasagiline and idebenone produced a synergistic effect that ameliorated RIR injury. In addition, the combined treatment provided neuroprotection via enhancement of the selective regulation of let-7 by Lin28A/B. These findings implied that a treatment with the combination of rasagiline and idebenone is a feasible treatment option for optic nerve diseases.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.