Proteome analysis of undiluted vitreous humor in patients with branch retinal vein occlusion

Abstract

The pathophysiological mechanisms of macular edema secondary to branch retinal vein occlusion (BRVO) remain unclear. To analyze the protein profile of human vitreous of patients with BRVO and to identify specific dysregulated proteins. Undiluted vitreous humor samples from patients with treatment naïve BRVO and 15controls with idiopathic floaters were analyzed in this clinical-experimental study using capillary electrophoresis coupled to a mass spectrometer (CE-MS) and tandem mass spectrometry (MS/MS). Quantitative analysis of the dysregulated proteins was performed with enzyme-linked immunosorbent assay (ELISA). Protein-protein interactions were depicted with the STRING database. A total of 84proteins were found in the human vitreous samples of 15patients with BRVO and 15controls. In all, 14proteins were significant when comparing the signal intensities of BRVO and control samples. Six significant dysregulated proteins with p< 0.001 were further verified with ELISA. Clusterin, complement factorC3, prostaglandin-H2 D‑isomerase and vitronectin were significantly upregulated in the BRVO group and opticin was downregulated. The protein interactions analysis showed associations with inflammatory cascades, matrix changes, mechanisms of cell survival und death. The results of the study reveal that the proteomic composition of vitreous humor differed significantly between the patients with BRVO and the controls. Whether the identified proteins may serve as potential biomarkers for pathophysiology, diagnostics or therapy should be examine in further studies.