Abstract
Purpose :
To investigate the expression of NOX2, a NADPH oxidase, and its regulation on endoplasmic reticulum stress (ERS)-mediated apoptosis and photoreceptor damage using a rat model of retinal detachment (RD).
Methods :
Animal model of RD was created in Brown Norway rats by subretinal injection of 1% sodium hyaluronate. Lentivirus NOX2 shRNA (LV-NOX2-sh) was constructed to inhibit NOX2 expression in vivo. The rats were randomly divided into four groups: normal control group (non-detachment), RD control group, negative control group (vehicle+RD) and LV-NOX2-sh+RD group. Expression of NOX2 and biomarkers of ERS pathway (CHOP, TRB3 and Caspase-12) were detected using quantitative real-time PCR and western blotting on day 1, 3, 5 and 7 after RD in each group. Non-detachment animals served as control. TdT-mediated fluorescein-16-dUTP nick-end labeling (TUNEL) assay was used to stain the apoptosis cells in histological sections. Retinal outer nuclear layer (ONL) thickness was measured to assess retina damage in each group.
Results :
NOX2 expression was significantly increased after RD. CHOP and TRB3 were over-expressed in RD control group. In LV-NOX2-sh group, the expression of NOX2 was notably inhibited in vivo. And the expressions of CHOP and TRB3 were decreased compared with those RD rats and vehicle+RD rats at the same time points. The ratio of TUNEL-positive photoreceptors in LV-NOX2-sh+RD group was significantly reduced accompany with less expression of Caspase-12. Meanwhile, the ONL thickness in LV-NOX2-sh+RD group was thicker than that both in RD group and vehicle+RD group.
Conclusions :
NOX2 expression is up-regulated in retinas and induces ERS pathway after RD. Inhibition of NOX2 protects photoreceptors through ERS-mediated apoptosis pathway in RD rat model. NOX2 may be a crucial regulatory molecule in ERS-mediated photoreceptor apoptosis after RD.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.