The Exosome-Transmitted lncRNA LOC100132249 Induces Endothelial Dysfunction in Diabetic Retinopathy.

Diabetic retinopathy (DR), one of the most common microangiopathic complications in diabetes, causes severe visual damage among working-age populations. Retinal vascular endothelial cells, the key cell type in DR pathogenesis, are responsible for abnormal retinal angiogenesis in advanced stages of DR. The roles of exosomes in DR have been largely unknown. In this study, we report the first evidence that exosomes derived from the vitreous humor of patients with proliferative DR (PDR-exo) promote proliferation, migration, and tube formation of human retinal vascular endothelial cells (HRVECs). We identified long noncoding RNA (lncRNA) LOC100132249 enrichment in PDR-exo via high-throughput sequencing. This lncRNA, also mainly derived from HRVECs, promoted angiogenesis both in vitro and in vivo. Mechanistically, LOC100132249 acted as a competing endogenous sponge of miRNA-199a-5p (miR-199a-5p), thus regulating the endothelial-mesenchymal transition promoter SNAI1 via activation of the Wnt/ß-catenin pathway and ultimately resulting in endothelial dysfunction. In conclusion, our findings underscored the pathogenic role of endothelial-derived exosomes via the LOC100132249/miR-199a-5p/SNAI1 axis in DR angiogenesis and may shed light on new therapeutic strategies for future treatment of DR. ARTICLE HIGHLIGHTS: This study provides the first evidence that exosomes derived from vitreous humor from patients with proliferative diabetic retinopathy participate in angiogenesis. The findings demonstrate an unreported long noncoding RNA (lncRNA), LOC100132249, by exosomal sequencing of vitreous humor. The newly found lncRNA LOC100132249, mainly derived from endothelial cells, promotes angiogenesis via an miRNA-199a-5p/SNAI1/Wnt/ß-catenin axis in a pro-endothelial-mesenchymal transition manner.

Vitreous Inflammatory Cytokines and Chemokines, Not Altered After Preoperative Adjunctive Conbercept Injection, but Associated With Early Postoperative Macular Edema in Patients With Proliferative Diabetic Retinopathy.

Purpose: To investigate the influence of preoperative adjunctive anti-VEGF drug (Conbercept) on vitreous inflammatory cytokines and chemokines profiles and whether those cytokines were associated with early macular edema (ME) after surgery for patients with proliferative diabetic retinopathy (PDR). Methods: In this post hoc analysis of the CONCEPT clinical trial, subjects with PDR underwent vitrectomy were included and vitreous samples were collected at the start of vitrectomy. Levels of vitreous VEGF, 17 inflammatory cytokines, and 11 chemokines were measured using Luminex multiplex technology. Subjects were then divided into groups based on with (Pre-IV) or without (No-Pre-IV) preoperative intravitreous injection of Conbercept; with or without early ME after surgery. Results: There was no difference between Pre-IV (13/30) and No-Pre-IV (7/29) concerning the ratio of patients with early ME (p = 0.17). After preoperative intravitreous injection of Conbercept, VEGF level dramatically decreased (p = 0.001), TNF-α (p = 0.002), and IP-10 (p = 0.018) increased in Pre-IV group. In patients with early ME after surgery, however, a number of cytokines increased, including IL-1ß (p = 0.008), IL-2 (p = 0.023), IL-4 (p = 0.030), IL-9 (p = 0.02), IL-10 (p = 0.002), IL-12 (p = 0.001), IL-13 (p = 0.031), IL-17A (p = 0.008), TNF-α (p = 0.012), CXCL9 (p = 0.023), G-CSF (p = 0.019), MCP-1 (p = 0.048), and RANTES (p = 0.016). Conclusion: We found the preoperative adjunctive Conbercept injection has limited influence on the levels of vitreous inflammatory cytokines and chemokines in PDR. The elevated levels of a series of cytokines might be associated with early inflammation after vitrectomy, which may lead to postoperative ME.

Monitoring intraocular proangiogenic and profibrotic cytokines within 7 days after adjunctive anti-vascular endothelial growth factor therapy for proliferative diabetic retinopathy.

PURPOSE: To monitor the intraocular proangiogenic and profibrotic cytokine profiles within 7 days after intravitreous injection of conbercept (IVC) for patients with proliferative diabetic retinopathy (PDR). METHODS: This prospective, randomized controlled, consecutive, comparative study included 157 eyes with PDR. Participant eyes underwent sham IVC or IVC and subsequent vitrectomy at days 2, 3, 4, 5, 6, 7 postinjection. The intraocular cytokines profiles were measured using beaded assay methods. RESULTS: After IVC, the vascular endothelial growth factor (VEGF)-A level in PDR vitreous decreased rapidly by approximately 10 times at day 2 (p = 0.00001) and kept at a low level at days 3, 4, 5, 6, 7 (p < 0.001, each compared with IVC-sham group). Similar tendency of the change in VEGF-A was observed in aqueous humour. The level of placenta growth factor (PIGF) in aqueous humour decreased 2 days after IVC whereas returned to baseline level after 5 days. The vitreous profibrotic cytokines, tissue growth factor (TGF)-ß1, TGF-ß2, TGF-ß3 and connective tissue growth factor did not increase after IVC in each group. CONCLUSION: We observed a remarkable and rapid decrease in intraocular VEGF-A, temporal decrease in PIGF from day 2 to day 4, increase in VEGF-C and VEGF-D from day 2 onwards, but no profibrotic switch in PDR eyes after IVC. The findings might suggest that ideal vitrectomy timing might be around 3 days after IVC.

Emerging Role of Exosomes in Retinal Diseases.

Retinal diseases, the leading causes of vison loss and blindness, are associated with complicated pathogeneses such as angiogenesis, inflammation, immune regulation, fibrous proliferation, and neurodegeneration. The retina is a complex tissue, where the various resident cell types communicate between themselves and with cells from the blood and immune systems. Exosomes, which are bilayer membrane vesicles with diameters of 30-150 nm, carry a variety of proteins, lipids, and nucleic acids, and participate in cell-to-cell communication. Recently, the roles of exosomes in pathophysiological process and their therapeutic potential have been emerging. Here, we critically review the roles of exosomes as possible intracellular mediators and discuss the possibility of using exosomes as therapeutic agents in retinal diseases.

PERFLUOROCARBON LIQUID-ASSISTED INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE VERSUS INTERNAL LIMITING MEMBRANE PEELING FOR HIGHLY MYOPIC MACULAR HOLE RETINAL DETACHMENT.

PURPOSE: To compare the efficacy of a modified perfluorocarbon liquid-assisted inverted internal limiting membrane (ILM) flap technique with the standard ILM peeling for the treatment of macular hole retinal detachment in highly myopic eyes. METHODS: This was a retrospective, consecutive, nonrandomized comparative study. Forty-two macular hole retinal detachment eyes of 42 patients were included into either a perfluorocarbon liquid-assisted inverted ILM flap technique group (n = 22, inverted group) or standard ILM removal group (n = 20, peeling group). Outcomes measured were macular hole closure, retinal reattachment, and best-corrected visual acuity at least 6 months after surgery. RESULTS: Macular hole closure was achieved in 20 eyes (90.9%) in the inverted group and in eight eyes (40%) in the peeling group (P < 0.01). Reattachment rates were 100% in the inverted group and 95% in the peeling group (P = 0.476). The mean best-corrected visual acuity improvement from baseline was 27.4 ± 19.9 Early Treatment Diabetic Retinopathy Study letters in the inverted group while the best-corrected visual acuity improvement was 13.6 ± 22.5 Early Treatment Diabetic Retinopathy Study letters in the peeling group (P = 0.044). CONCLUSION: The perfluorocarbon liquid-assisted inverted ILM flap technique was effective in sealing the macular hole, reattaching retina, and improving visual function postoperatively in highly myopic macular hole retinal detachment.