Abstract
Purpose :
Few data exist regarding the protein composition of idiopathic epiretinal membranes. In the present study we compared the proteome of epiretinal membrane of idiopathic epiretinal membrane (iERM) to the proteome of the internal limiting membrane (ILM) of idiopathic macular hole (iMH).
Methods :
The study was approved by the Zealand Region Committee on Health Reasearch Ethics (permission identification SJ-393), and adhered to the tenets of Helsinki declaration. Twelve samples of idiopathic epiretinal membrane and 12 samples of internal limiting membrane were obtained from patients during therapeutic vitrectomy. The samples were analyzed with nano-liquid chromatography tandem mass spectrometry. The retrieved data files were used to search against human protein database from UniProt using Max Quant Software. Identified proteins were filtered with Perseus software. Perseus was also used to conduct a student’s t-test with a permutation based false discovery rate (FDR). ConsensusPathDB was used for bioinformatic analysis.
Results :
A total of 2,183 different proteins were identified. Amongst the 357 proteins identified in all samples 70 proteins were significantly increased in content (p<0.05, FDR < 0.01) in iERM. Upregulated proteins in epiretinal membranes were components of the cytoskeleton or played a role in signal transduction, inflammation and cellular metabolism. Upregulated pathways in iERM included platelet derived growth factor receptor beta signaling pathway, beta 1 and beta 3 integrin cell surface interactions and leukocyte transendothelial migration. In total 11 proteins were significantly increased in content in ILM of macular holes (p<0.05, FDR < 0.01) comprising mainly proteins involved in cellular adhesion, proliferation and differentiation. Principal component analysis as well as cluster analysis showed that iERM and ILM of iMH were generally different.
Conclusions :
Epiretinal membrane in iERM consists of different proteins than ILM in patients with iMH.
The differences between the two conditions were statistically significant. The study identified proteins that have not earlier been associated with iERM. Proteins increased in iERM were involved in signal transduction, integrin signaling and inflammatory processes.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.