Abstract
Purpose :
To determine the effect of poly(IC) subretinal injection on programmed retinal cell death.
Methods :
Male 6-8 weeks old C57Bl/6J mice (n=30) were used. Subretinal injections were performed using poly(IC) (polyinosinicpolycytidylic acid/potassium salt) or phosphate buffer saline (PBS). The animals were followed for 2 days, 5 days and 7 days after subretinal injection. In vivo spectral domain-optical coherence tomography (SD-OCT) was employed to verify successful subretinal injection at the baseline. SD-OCT was also performed at the end of the follow-up period prior to animal sacrifice. The mice were transcardially perfused and the eyes were enucleated and cryosectioned. Ocular sections were systematically chosen and stained for hematoxylin and eosin (H&E) and for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). The number of TUNEL-positive cells as well as the thickness of outer nuclear layer (ONL) were estimated using StereoInvestigator software (v. 10, MicroBrightField Inc., USA).
Results :
Both injections of PBS and poly(IC) caused retinal detachment. However, polyIC-injected group with a 2-day follow-up showed a significant increase in TUNEL-positive cells (5.2±1.48 cells/100 µm of ONL length, mean±SD) found in ONL as compared to other poly (IC) time-points (5-day group: 1.2±0.82 cells/100 µm of ONL length; 7-day group: 0.37±0.48 cells/100 µm of ONL length) or PBS-injected eyes (2-day group: 0.65±0.82 cells/100 µm of ONL length; 5-day group: 0.38±0.40 cells/100 µm of ONL length; 7-day group: 0.34±0.29 cells/100 µm of ONL length).
Conclusions :
Subretinal injection of poly(IC) causes acute programmed cell death of photoreceptor cells. The use of SD-OCT is particularly important to verify and follow-up this preclinical model.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.