LncRNA TDRG1-Mediated Overexpression of VEGF Aggravated Retinal Microvascular Endothelial Cell Dysfunction in Diabetic Retinopathy.

Feng’E Chen,Xun Xu,Tianwei Qian,Qiaoyun Gong,Xiaolan Bian,Ping Yu,Ying Fan,Wenpei Dong

doi:10.3389/fphar.2019.01703

Abstract

PurposeDiabetic retinopathy (DR), a neurovascular disease, is one of the leading causes of blindness in working-age adults. Long noncoding RNAs (lncRNAs) have attracted attention as indicators for DR. This study aimed to characterize the role of lncRNA human testis development–related gene 1 (TDRG1) and its modulation of vascular endothelial growth factor (VEGF) in deteriorating DR.MethodsTissue samples were obtained from patients with epiretinal membranes (EMs) or proliferative DR, and human retinal microvascular endothelial cells (HRECs) were cultured with high-glucose medium to mimic DR as the in vitro model. The expression of lncRNA TDRG1 and VEGF was determined by immunofluorescence staining, Western blotting, and RT-qPCR. Transfection of small-interfering RNA was conducted to knock down target gene expression. HREC functions were evaluated by cell viability, fluorescein isothiocyanate (FITC)-dextran extravasation, migration, and tube formation assays under different conditions.ResultsLncRNA TDRG1 and VEGF were found to be co-expressed and significantly upregulated in fibrovascular membranes (FVMs) from DR patients compared to those from EM patients. In the in vitro model, hyperglycemic treatment markedly increased the expression of lncRNA TDRG1 and VEGF at the mRNA and protein levels, which promoted cell proliferation and migration, enhanced permeability, and disrupted tube formation of HRECs. However, knockdown of lncRNA TDRG1 or VEGF notably decreased the expression of VEGF and reversed the impaired functions of high-glucose-treated HRECs.ConclusionsLncRNA TDRG1 promoted microvascular cell dysfunction via upregulating VEGF in the progression of DR and may serve as a potential therapeutic target in DR treatment.

Highlights

Diabetic retinopathy (DR) is one of the leading causes of blindness in working-age adults worldwide (Cheung et al, 2010)
Immunofluorescence staining showed the Long noncoding RNAs (lncRNAs) testis development–related gene 1 (TDRG1) and vascular endothelial growth factor (VEGF) were expressed in these two kinds of tissue samples, and high fluorescence was observed in the fibrovascular membrane (FVM), especially in the vessel walls (Figure 1B)
Expression of lncRNA TDRG1 and VEGF was increased in FVMs compared to epiretinal membranes (EMs) (Figures 1C, D), as shown by RT-qPCR and analyzed by Student’s t-tests

Summary

Introduction

Diabetic retinopathy (DR) is one of the leading causes of blindness in working-age adults worldwide (Cheung et al, 2010). This type of retinopathy is a severe complication of diabetes mellitus (DM), and its prevalence is increasing dramatically due to the high incidence of DM (Antonetti et al, 2012).In 2010, the prevalence of DM in China was estimated to be 11.6% in the adult population (Xu et al, 2013). The pathology of the clinical changes in DR is characterized by retinal microvascular dysfunction that leads to increased vascular permeability, destroyed vascular tubes, and breakdown of the blood-retinal barrier (BRB) (Antonetti et al, 2006). Novel pharmacological therapies targeting biochemical mechanisms that promote EC function may effectively ameliorate DR

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