Abstract
Purpose :
We performed a comparative proteomics study of vitreous fluid obtained from sarcoidosis and non-sarcoidosis uveitis patients to identify specific protein expression patterns in sarcoidosis uveitis.
Methods :
In this study, we analyzed 12 vitreous fluid samples (8 from sarcoidosis uveitis patients and 4 from non-sarcoidosis uveitis patients) obtained at the time of vitrectomy surgery. Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) was performed to compare the protein expression patterns in the two groups, and protein spots showing a statistically significant difference (p≤0.05) in expression and a fold change of ±2.0 or greater were considered to be differentially expressed. Differentially expressed protein spots were picked from the gel and digested overnight with trypsin and the digests were then extracted from gel plugs and dried down. The dried samples were re-suspended and analyzed by LTQ XL mass spectrometer (Thermo Scientific) and raw data files of each sample was searched against the most recent fasta databases for Homo sapiens from Uniprot using Proteome Discoverer 1.4 (Thermo Scientific) and the SEQUEST algorithm.
Results :
A total of 56 proteins were identified from 15 differentially expressed spots. Nine spots were upregulated and 6 were downregulated in sarcoidosis uveitis. HP protein (serine-type endopeptidase), zinc-alpha-2-glycoprotein, transthyretin and Alpha-2-macroglobulin were identified in the upregulated spots, whereas protein alpha-1-microglobulin/bikunin precursor (AMBP) and clusterin were found in the downregulated spots. Complement C3, fibrinogen gamma chain, and Ig alpha-1 chain C region were identified in both the up- and downregulated spots.
Conclusions :
HP protein, zinc-alpha-2-glycoprotein, transthyretin and Alpha-2-macroglobulin were identified as upregilated proteins in the vitreous fluid of sarcoidosis uveitis patients.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.