Inhibition of TRB3 Protects Photoreceptors against Endoplasmic Reticulum Stress-Induced Apoptosis after Experimental Retinal Detachment

Abstract

Purpose: To investigate the expression of tribbles homologue 3 (TRB3) and its regulation on endoplasmic reticulum stress (ERS)-induced photoreceptor apoptosis after retinal detachment (RD) using a rat model.

Methods: RD animal model was created in Wistar rats by subretinal injection of 1% sodium hyaluronate. At various time points after RD, expression of TRB3 was detected by quantitative real-time PCR and Western blotting. TRB3 protein distribution in retina was evaluated by immunohistochemistry. RNA interference was used to inhibit TRB3 expression and subretinal injection of lentivirus TRB3 shRNA (LV-TRB3-sh) was performed. The rats were then randomly divided into four groups: normal control group, RD group, vehicle + RD group and LV-TRB3-sh + RD group. The mRNA and protein level of TRB3 as well as Caspase-12 were detected. TdT-mediated fluorescein-16-dUTP nick-end labeling (TUNEL) assay was used to detect the apoptosis of retinal cells. Retinal outer nuclear layer (ONL) thickness was measured to assess retina damage in each group.

Results: TRB3 expression and TRB3-positive cell count were significantly increased after RD and peaked at day 3 after RD. The ratio of TUNEL-positive photoreceptors and expression of ERS-induced apoptosis marker Caspase-12 in LV-TRB3-sh + RD group were significantly reduced. The ONL thickness in LV-TRB3-sh + RD group was thicker than that both in RD group and vehicle + RD group.

Conclusion: TRB3 expression is up-regulated in retinas after RD and knockdown of TRB3 protects photoreceptors against ERS-induced apoptosis. TRB3 may be a crucial molecule in photoreceptor apoptosis induced by ERS after RD.

• Apoptosis
• endoplasmic reticulum stress
• photoreceptor
• retinal detachment
• TRB3

Acknowledgments

We are very grateful to Tianhong Dai, Ph.D. (Assistant Professor of Harvard Medical School, Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA) and Yu Chen, Ph.D. (Departments of Pharmacology and Ophthalmology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4965, USA) for their critical reading of the manuscript.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This study was supported by the National Basic Research Program of China “973 Program” (2011CB707506), the National Natural Science Foundation of China Grant (81170861, 81271030 and 81400413), Shanghai Key Basic Research Grant (11JC141601), Shanghai Key Medical Research Grant (1341195400) and Shanghai Scholar Leadership Grant (12XD1404100).

Supplemental Material

Supplemental data for this article can be accessed at www.tandfonline.com/icey.