Comparison of tear proteins between healthy and early diabetic retinopathy patients.

Objectives: To identify potential prognostic or diagnostic marker tear proteins for early diabetic retinopathy (DR) and to investigate the pathogenesis of this disease using proteomics techniques.

Design And Methods: The tear proteins expressed in patients suffering from diabetes mellitus without the retinopathy symptoms, nonproliferative diabetic retinopathy and healthy volunteers were analyzed by 2-DE. The differentially expressed proteins in patients were identified by ESI-Q-TOF and confirmed by Western blotting.

Results: Proteins which were differentially expressed with statistical significance (P<0.05) in two diabetic groups as compared to those in healthy group were selected and identified by ESI-Q-TOF MS/MS. Among these proteins, three proteins (LCN-1, HSP27 and B2M) were found to exhibit a progressive reduction in two disease groups. The expression levels of which might be useful as diagnostic biomarkers of DR were verified by Western blotting

Conclusions: Proteomic analysis using tear is a novel approach that can provide insight into possible biomarker and the pathogenesis of early DR.