Differences in aqueous humor protein profiles in patients with proliferative diabetic retinopathy before and after conbercept treatment

To investigate the changes in aqueous humor (AH) protein profiles before and after intravitreal conbercept (IVC) treatment in proliferative diabetic retinopathy (PDR) patients. Ten PDR patients provided 20 samples of AH before (pre group) and after (post group) IVC treatment. Liquid chromatography-tandem mass spectrometry was performed to identify proteins. Bioinformatics analysis was used to explore the functional relevance of differ-entially expressed proteins (DEPs) and hub proteins. Parallel reaction monitoring (PRM) method was used to verify the hub proteins in another 8 samples of AH before and after IVC treatment in 4 PDR patients. A total of 30 DEPs were identified, consisting of 14 downregulated proteins and 16 upregulated proteins. Bioinformatics analysis indicated that DEPs mostly involved in neutrophil degranulation, antioxidant activity, secretory granule lumen, cytoplasmic vesicle lumen, vesicle lumen, and fluid shear stress. HP, VEGFA, CTSD, and LYZ were identified as hub proteins, among which HP and CTSD were verified by PRM. In addition to decreasing the intravitreal vascular endothelial growth factor level, IVC may alter the AH protein profile in PDR patients, especially HP and CTSD, with the DEPs involved in neutrophil degranulation, antioxidant activity, secretory granule lumen, cytoplasmic vesicle lumen, vesicle lumen, and fluid shear stress. Significance: Patients with proliferative diabetic retinopathy (PDR) regularly receive intravitreal conbercept treatment these days. The effect of this treatment has been determined by previous studies. However, the mechanism of IVC in PDR is not eventually determined. No studies have compared the aqueous humor (AH) protein profile before and after IVC treatment in the same patient. This is a topic deserving of further exploration. A proteomic method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized in this study to analyze and assess the AH samples to explore the mechanism underlying the effects of IVC treatment on PDR.