Proteome Analysis of Urinary Biomarkers in a Bovine IRBP-Induced Uveitis Rat Model via Data-Independent Acquisition and Parallel Reaction Monitoring Proteomics.

Weiwei Qin,Xuyan Qin,Lujun Li,Youhe Gao

doi:10.3389/fmolb.2022.831632

Abstract

Uveitis, a group of intraocular inflammatory diseases, is one of the major causes of severe visual impairment among the working-age population. This study aimed to screen potential urinary biomarkers for uveitis based on proteome analysis. An experimental autoimmune uveitis (EAU) rat model induced by bovine interphotoreceptor retinoid-binding protein (IRBP) was used to mimic uveitis. In discovery phase, a total of 704 urinary proteins were identified via data-independent acquisition (DIA) proteomic technique, of which 76 were significantly changed (34, 36, and 37 on days 5, 8, and 12, respectively, after bovine IRBP immunization). Gene Ontology annotation of the differential proteins indicates that acute-phase response, innate immune response, neutrophil aggregation, and chronic inflammatory response were significantly enriched. Protein-protein interaction network indicates that these differential urinary proteins were biologically connected in EAU, as a group. In validation phase, 17 proteins having human orthologs were verified as the potential markers associated with uveitis by parallel reaction monitoring (PRM) targeted quantitative analysis. Twelve differential proteins changed even when there were no clinical manifestations or histopathological ocular damage. These 12 proteins are potential biomarkers for early diagnosis of uveitis to prevent the development of visual impairment. Five differential proteins changed at three time-points and showed progressive changes as the uveitis progressed, and another five differential proteins changed only on day 12 when EAU severity peaked. These 10 proteins may serve as potential biomarkers for prognostic evaluation of uveitis. Our findings revealed that the urinary proteome could sensitively reflect dynamic pathophysiological changes in EAU, and represent the first step towards the application of urinary protein biomarkers for uveitis.

Highlights

Uveitis is a group of intraocular inflammatory diseases that mainly involve the uvea, the blood vessel-rich pigmented middle layer of the wall of the eye
This study aimed to identify potential urinary protein biomarkers related to uveitis by using the bovine IRBPinduced uveitis rat model
On day 16, mild vitritis and retinal folds were observed (Figure 2). These clinical manifestations and pathological changes revealed the successful generation of bovine interphotoreceptor retinoid-binding protein (IRBP)-induced uveitis model

Summary

Introduction

Uveitis is a group of intraocular inflammatory diseases that mainly involve the uvea, the blood vessel-rich pigmented middle layer of the wall of the eye. Uveitis carries a high risk of vision loss and usually affects people aged 20–50 years (Rothova et al, 1992; Gritz and Wong, 2004; Krishna et al, 2017). Approximately 5–25% of irreversible blindness is caused by uveitis and its complications (Rao, 2013; Tsirouki et al, 2018). In addition to infectious agents, autoimmune reactions are one of the main causes of uveitis. Corticosteroids and immunomodulatory agents are the mainstay of treatment (Larson et al, 2011). There are some uveitis patients who fail to respond to treatment. Long-term treatments may have several intraocular and systemic side effects, such as high intraocular pressure, sterile endophthalmitis, and nephrotoxicity (Jonas et al, 2003; Moshfeghi et al, 2003)

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