Significant Up-regulation of PRDX1 in Retinal detachment

Abstract

Purpose : Peroxiredoxins constitute a family of anti-oxidant enzymes which are up-regulated during damage conditions and neutralize tissue hydrogen peroxide. Oxidative stress is important to the pathobiology of retinal detachment (RD). PRDX1 is expressed in CNS microglia and may also contribute to neuroinflammation. We evaluated PRDX1 expression in experimental RD versus controls and the impact of microglia depletion on PRDX1 expression. We evaluated PRDX1 expression in patient RD vitreous vs controls.

Methods : This study was approved by the OSU IACUC and IRB. Murine RDs were induced in anesthetized mice by subretinal injection of undiluted hyaluronic acid into left eyes. Eyes were enucleated for proteomic analysis with iTRAQ labeling. Mass Spectrometry was performed to identify differentially up- and down-regulated proteins. RT-PCR, ELISA, and IHC were performed. Microglial depletion was performed using oral PLX5622 fed daily x 2 weeks prior to and during RD generation followed by PRDX1 IHC. Human RD versus control subjects with a similar ethnic background were recruited from multiple referral-based subspecialty practices (OVER-PVR study). Informed consent was obtained. RD and control (epiretinal membrane and macular hole) vitreous samples were collected during surgery.

Results : PRDX1 was one of the top up-regulated inflammatory proteins in murine RD eyes vs controls by iTRAQ. We confirmed significant up-regulation of PRDX1 in murine RD eyes vs controls by ELISA at 1 and 2wk post-RD (n=15/group, (2.0±0.6 vs. 1.4±0.2) p=0.0005 and (1.8±0.5 vs. 1.6±0.4) p=0.0470, respectively). PRDX1 was predominantly present in the outer nuclear and outer plexiform layers (ONL and OPL) with respect to other retinal layers. PRDX1 was not significantly up-regulated at the transcriptional level at day 3/wk2 (n=4/group; n=10/group). In mice with microglial depletion the levels of retinal PRDX1 did not increase in day 3 RDs compared with fellow eye controls. PRDX1 was significantly up-regulated by ELISA in patient RD vitreous samples compared with controls (n=25 RDs; n=21 controls; (1.8±2.0 vs. 0.3±0.4) p=0.0007).

Conclusions : PRDX1 is significantly upregulated in experimental and human RDs at the translational level. Further study is needed to understand the mechanism of increase in PRDX1 and the role of retinal microglia during retinal damage.

This is a 2020 ARVO Annual Meeting abstract.