Proteomic Alterations in the Vitreous of Diabetic Mice

Abstract

Purpose : Diabetic retinopathy (DR) is the most common complication of diabetes and the number one cause of blindness in the United States. This microvascular disease is caused by prolonged hyperglycemia and characterized by leaky retinal vasculature and ischemia-induced angiogenesis in the retina. Vitreous humor (VH) is a gel-like biofluid in the posterior segment of the eye between the lens and the retina, and because of its location and vascular supply, alterations to the proteins and macromolecules within the retina can also be observed in the VH. Current understanding of VH proteomic changes associated with DR is quite limited; therefore, the purpose of this study was to identify proteomic alterations in VH associated with DR.

Methods : Vitreous samples from control and streptozotocin (STZ)-induced diabetic mice were collected by evisceration. Comprehensive proteomic analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results : We identified a total of 1,367 proteins in the vitreous humor, and the levels of 72 proteins were significantly altered in the mice with DR compared to non-diabetic controls. The proteins demonstrating the greatest change between diabetic and control mice are: Tubulin beta-5 chain (Tubb5), 14-3-3 protein epsilon (Ywhae), Tubulin beta-4B chain (Tubb4b), Gamma-enolase (Eno2), Tubulin beta-2A (Tubb2a), 14-3-3 protein theta (Ywhaq), Lengsin (Lgsn), Glutamine synthetase (Glul), Tubulin alpha-1B chain (Tuba1b), and Rhodopsin (Rho).

Conclusions : LC-MS/MS proteomic characterization of vitreous fluid provides a comprehensive means of analyzing altered protein expression in DR. This offers not only a novel means of studying DR pathology in a controlled environment, but also a critical tool for developing diagnostic biomarkers and an avenue for evaluating future therapeutics.

This is a 2020 ARVO Annual Meeting abstract.