Detection of Retinal Proteins in Saliva and Serum Following Retinal Photocoagulation in Rabbits

Abstract

Purpose: : Retinal injuries affecting the photoreceptors and/or the retinal pigment epithelium (RPE) may result in leakage of subcellular fragments of retinal-specific proteins into the systemic circulation through the underlying choroid. These molecules may be detected in body fluids following the injury. To test this hypothesis, we used Liquid chromatography/Mass spectrometry (LC/MS/MS) to detect retinal proteins in body fluids of Dutch Belted rabbits following retinal photocoagulation

Methods: : Rabbits were treated using an Nd:YAG laser (532 nm) to create retinal photocoagulation. Saliva and serum samples were collected from 15 and 9 rabbits respectively both pre and post laser treatment. Unpaired control samples were also obtained from non-treated animals. Presence or absence of retinal-specific proteins was confirmed by LC/MS/MS analysis.

Results: : Retinal-specific proteins were detected in 46.7% of saliva (n=15) and 100% of pooled serum (n=3) from samples taken 24 hours after laser injury. Proteins identified from saliva included Retinal Guanylyl Cyclase (n=2), Guanine Nucleotide Binding Proteins (n=3) and Guanylyl Cyclase Activating Protein (n=2). Proteins identified from serum included Rhodopsin (n=1), Guanine Nucleotide Binding protein β 5 (n=1), and Regulator of G protein Signaling 9 (n=1). None of these proteins were detected in any paired or unpaired samples from non-treated control rabbits.

Keywords: retina • proteomics • laser