TMT-Based Quantitative Proteomic Analysis of vitreous humor in proliferative diabetic retinopathy

Objective To study the changes in vitreous humor proteins profile of proliferative diabetic retinopathy (PDR) and macular hole (MH) / epimacular membrane (EMM). Further, to identify potential biomarkers in PDR by screening differentially expressed proteins (DEPs). Methods The study used tandem mass tag (TMT) combined with LC-MS/MS for the identification of DEPs in vitreous samples of PDR and MH/EMM patients. The identified DEPs were analyzed bioinformatically to screen out candidate proteins for potential research potential. Using the parallel reaction monitoring (PRM) technique, 30 proteins with potential effects were targeted and validated. Results TMT combined with LC-MS/MS proteomic analysis isolated and identified a total of 4812 peptides and 877 proteins were identified, including a total of 59 DEPs (fold change > 1.2, P  < 0.05). Bioinformatics analysis showed that DEPs were mainly involved in important biological processes such as cell transformation, stimulus-response, cellular processes, bioregulation, localization, and immune and metabolic processes. Validated by PRM, 23 proteins were quantified, the overall trends of the label-free quantification and PRM results were consistent. Among them, coagulation factor V (FV), profilin-1 (PFN1), thioredoxin (TXN), ferritin light chain (FTL) and Selenoprotein P (SeP) and not only showed consistent significant quantitative trends, but P  < 0.05. Conclusion This study shows alterations in vitreous humor proteins profile of PDR. These five candidate proteins (FV, PFN1, TXN, FTL, SeP) can be used as biomarkers of PDR, providing new research directions and therapeutic targets for the pathogenesis of PDR.