Abstract
Purpose: :
Vitreous body plays an important role in the pathogenesis of proliferative diabetic retinopathy (PDR). Accumulation of cytokines in posterior precortical vitreous pocket (PPVP) is known for the induction of diabetic macular edema. In this study, proteome analysis using mass spectrometer was performed to determine the proteins specifically expressed in PPVP comparison to peripheral vitreous in patients with PDR and epiretinal membrane (ERM).
Methods: :
Vitreous samples from PPVP and peripheral vitreous were collected during vitrectomy using the 25–gauge (25G) system to selectively collect the vitreous samples. Samples were collected from 3 patients each with PDR and ERM. SDS–PAGE and peptide PAGE were performed to separate proteins followed by gel scanning and spot removal. Protein identification was carried out by ion spray LC–MS/MS (LCQ Deca XP plus, ThermoElectron).
Results: :
In 2 PDR patient samples, SDS–PAGE patterns were different between PPVP and peripheral vitreous. These differentially expressed PPVP proteins were TNF–a, proteasome activator 2, and other retinal proteins. In ERM patients, each SDS–PAGE patterns were identical.
Conclusions: :
Differentially expressed proteins in PPVP were observed in patients with PDR associated with macular edema. These PPVP proteins were identified as TNF–a, proteasome activator 2, and other retinal proteins. Functional role of these proteins in relation with the pathogenesis of PDR is under investigation.
Keywords: proteomics • diabetic retinopathy • vitreous