Abstract
Purpose :
To investigate the neuroprotective effect of mGluR5 activation in rat retina after ischemia/reperfusion injury
Methods :
The SD rats were anesthetized and the pupil was dilated. The anterior chamber was punctured with a 30G needle which was connected to a bottle containing normal saline. Intraocular pressure was raised to 110 mmHg for 60 min and later the infusion needle was removed from the anterior chamber. 5µl CHPG was given to the rat intravitreally 30min before the injury in the treated group. The rats were then euthanatized at 2, 3 and 7 days after reperfusion, and their eyes were enucleated for flurogold analysis, H&E staining, western blotting analysis and real-time PCR.
Results :
Treatment with CHPG resulted in 73.5% of labeled RGCs, which is significantly higher than the untreated I/R group. The inner plexiform layer (IPL) in treated group is thicker than the untreated injury group, proven by H&E staining. The results of western blot analysis confirmed that mGluR5 activation reduced active caspase-3 expression and iNOS expression which were induced by retinal I/R injury. Also, the results from real-time PCR analysis demonstrated that activation of mGluR5 significantly reduced the expression TNF-α mRNA and IL-1β mRNA in retinas compared with the untreated group.
Conclusions :
Our results showed that mGluR5 activation dramatically promote RGCs survival in a rat retianl I/R model. This protective action appears to be attributable to inhibition of neurotoxic mediators release and/or direct suppression of RGC apoptosis.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.