miR-15a/16 inhibits TGF-beta3/VEGF signaling and increases retinal endothelial cell barrier proteins

Abstract

Hyperglycemia is a significant risk factor for diabetic retinopathy and induces multiple biochemical changes, including inflammation and endothelial dysfunction in the retina. Alterations in microRNA expression have been implicated in the pathological responses of diabetic retinopathy and the manipulation of microRNA may provide powerful strategy for therapeutics. Among the predicted targets of miR-15a and -16 are TGF-beta3, SMAD2/3, and VEGF, all of which are known to play a role in vascular endothelial functions. The purpose of this study was to investigate the hypothesis that miR-15a/16 inhibits TGF-beta3/VEGF signaling to maintain retinal endothelial cell barrier protein levels. Human primary retinal endothelial cells (REC) were maintained in normal (5 mM) glucose or transferred to high glucose medium (25 mM) for 3 days. REC were transfected with miRNA mimics (hsa-miR-15a-5p and -16-5p). Retinal lysates from miR-15a-transgenic mice were also analyzed. We demonstrated that overexpression of miR-15a/16 resulted in decreased TGF-beta3 signaling and VEGF levels in cultured REC grown in high glucose conditions. In addition, the levels of tight junction proteins, zonula occludens-1 (ZO-1) and occludin, were elevated in REC following overexpression of miR-15a and -16. Overexpression of miR-15a and - 16 played a role in reducing cellular permeability through inhibition of VEGF signaling in REC cultured under high glucose conditions. Using miR-15a-transgenic mice, we demonstrated the regulatory role of miR-15a on TGF-beta3 signaling and tight junction proteins in vivo. Our outcomes suggest that miR-15a/16 maintain the retinal endothelial cell barrier by reducing TGFbeta3/VEGF signaling and increasing levels of key tight junction proteins.

A compartmentalized microfluidic chip with crisscross microgrooves and electrophysiological electrodes for modeling the blood–retinal barrier

“…Although there was no significant difference in R between ARPE-19 and HREC at the 3 rd day and HREC. [43][44][45][46] In our hands this has also been reproduced as is shown in Fig. S6.…”

miR15a regulates NLRP3 inflammasome proteins in the retinal vasculature

“…In this study, we focused on the role of miR15a and its potential role in reducing NLRP3 in-flammasome proteins in retinal endothelial cells. Previous work in our lab recently demonstrated that miR15a regulated insulin signaling (Jiang et al, 2018), and miR15a maintained the retinal endothelial barrier in REC and mice (Ye et al, 2017). Furthermore, miR15a has been shown to decrease inflammatory cytokines (Wang et al, 2016).…”

“…Experiments were done using miR15a endothelial cell specific knockout mice (Ye et al, 2016) and overexpressing mice (Ye et al, 2017). Mice of both sexes at 3 months of age were used.…”

MicroRNA‑15a‑5p induces pulmonary artery smooth muscle cell apoptosis in a pulmonary arterial hypertension model via the VEGF/p38/MMP‑2 signaling pathway

“…In addition, the overexpression of miR-15a-5p inhibited the proliferation and promoted the apoptosis of PASMcs in rats with McT-induced PAH through the suppression of VEGF expression. Ye et al reported that miR-15a reduced inflammation in the retinal endothelial cell barrier by reducing transforming growth factor-b3/VEGF signaling (26). However, the results were obtained from one primary cell type only, which is a limitation of the present study.…”