Proteomic Analysis of Vitreous Humor in Retinal Vein Occlusion

Abstract

PurposeTo analyze the protein profile of human vitreous of untreated patients with retinal vein occlusion (RVO).MethodsSixty-eight vitreous humor (VH) samples (44 from patients with treatment naïve RVO, 24 controls with idiopathic floaters) were analyzed in this clinical-experimental study using capillary electrophoresis coupled to mass spectrometer and tandem mass spectrometry. To define potential candidate protein markers of RVO, proteomic analysis was performed on RVO patients (n = 30) and compared with controls (n = 16). To determine validity of potential biomarker candidates in RVO, receiver operating characteristic (ROC) was performed by using proteome data of independent RVO (n = 14) and control samples (n = 8).ResultsNinety-four different proteins (736 tryptic peptides) could be identified. Sixteen proteins were found to be significant when comparing RVO and control samples (P = 1.43E-05 to 4.48E-02). Five proteins (Clusterin, Complement C3, Ig lambda-like polypeptide 5 (IGLL5), Opticin and Vitronectin), remained significant after using correction for multiple testing. These five proteins were also detected significant when comparing subgroups of RVO (central RVO, hemi-central RVO, branch RVO) to controls. Using independent samples ROC-Area under the curve was determined proving the validity of the results: Clusterin 0.884, Complement C3 0.955, IGLL5 1.000, Opticin 0.741, Vitronectin 0.786. In addition, validation through ELISA measurements was performed.ConclusionThe results of the study reveal that the proteomic composition of VH differed significantly between the patients with RVO and the controls. The proteins identified may serve as potential biomarkers for pathogenesis induced by RVO.

iTRAQ Quantitative Proteomic Analysis of Vitreous from Patients with Retinal Detachment

“…By combining iTRAQ labeling with 2D-nano-LC-MS/MS, 1030 proteins were identified with 6078 peptides, of which 2613 correspond to unique peptides ( Supplementary Table S1 ). To recognize which proteins were newly found in the present study, the identified proteins were compared to previous vitreous proteomics reports [ 19 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ], as seen in Supplementary Table S2 .…”

“…In the present study, 1030 proteins were identified with 6078 peptides, of which 2613 correspond to unique peptides. These proteins were compared to previous vitreous proteomics reports ( Supplementary Table S2 ), including twelve studies in which vitreous were collected by pars plana vitrectomy [ 19 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 35 ] and one study in which vitreous core was aspirated from post-mortem healthy eyes [ 34 ]. Table 3 displays the total number of proteins identified in the vitreous using distinct experimental set-ups, including the number of proteins found exclusively in each study.…”

Roles of exosomes in the normal and diseased eye

“…Several recent studies using proteomic, nucleic acid, and lipidomic approaches identified interesting potential vitreal biomarkers in retinal vein occlusion (Reich et al, 2016), neovascular AMD (Menard et al, 2016; Nobl et al, 2016), diabetic retinopathy (Jin et al, 2016), and primary open-angle glaucoma (Agnifili et al, 2015). However, none of these studies explored or discussed the role of exosomes or other EVs in the transport to and presence of biomarkers in the VH.…”

Recent advances in CE and microchip‐CE in clinical applications: 2014 to mid‐2017

“…An interesting study on protein analysis in the vitreous humor of the eye was reported by Reich et al. . These investigators examined patients with retinal vein occlusion and compared them to a set of controls.…”