Ribonuclease attenuates retinal ischemia reperfusion injury through inhibition of inflammatory response and apoptosis in mice.

The present study was aimed to reveal the function of extracellular RNAs (exRNAs) in retinal ischemia reperfusion (I/R) injury, and evaluate whether RNase administration can effectivelyreduce I/Rinjury. A retinal I/R injury C57BL/6J wild-type mice model was established by elevating intraocular pressure for 1 h. All mice received 3 doses of RNase or the same dose of normal saline at different time points. After 7 days of reperfusion, retinal damage was quantified by counting retinal ganglion cells and measuring retinal layer thickness. The apoptotic retinal cells were detected by the TUNEL experiment, and the expressions of caspase-3, proinflammatory cytokines in retinal tissues, and glial fibrillary acidic protein (GFAP) protein and mRNA were detected to determine the underlying mechanism. It was found that RNase administration (1) reduced the significant loss of retinal morphology caused by I/R injury; (2) down-regulated the expression of NF-κBp65, IL-6 and GFAP relative to the I/R mice; (3) decreased the apoptosis of retinal cells and the levels of caspase-3; (4) attenuated exRNAs levels in retinal tissues on day 7 after retinal I/R. In short, increased exRNAs may contribute to retinal I/R damages in mice, and RNase therapy can effectively attenuate retinal damage by reducing inflammatory response and apoptosis.