Retinal Disease and Metabolism

Retinal diseases, such as diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinopathy of prematurity (ROP), are some of the leading causes of blindness all over the world [...

Upregulation of Mir-21 Levels in the Vitreous Humor Is Associated with Development of Proliferative Vitreoretinal Disease.

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression by post-transcriptional inhibition of mRNA translation. Dysregulation of miRNAs, including circulating miRNAs, has been reported to play an important role in the development of various diseases, including fibrotic diseases. Aberrant expression of miRNAs in the vitreous humor of vitreoretinal diseased eyes has been reported. However, the expression pattern of miRNAs present in the vitreous humor of proliferative vitreoretinal disease (PVD) patients, including proliferative diabetic retinopathy (PDR), and proliferative vitreoretinopathy (PVR), remains unknown. To investigate the factors important for the development of PVD, we characterized the miRNAs present in the vitreous humor of PVD patients and analyzed the expression profiles of 377 miRNAs using quantitative polymerase chain reaction-based miRNA arrays. The expression of a specific subset of miRNAs, previously reported to be associated with the development of angiogenesis and fibrosis, was significantly altered in the vitreous of PVD patients. Among these miRNAs, we identified miR-21 as a candidate fibrotic miRNA with an important role in the pathogenesis of PVD. Increased miR-21 levels in the vitreous were associated with retinal fibrosis, including PVR and PDR. Because epithelial-mesenchymal transition (EMT) of retinal pigment epithelial cells (RPECs) plays a critical role in retinal fibrosis, the expression of miR-21 in human RPECs was determined. Its expression in RPECs was induced by transforming growth factor-β, a key growth factor involved in fibrogenesis, and was enhanced by high glucose culture conditions, suggesting that miR-21 expression positively correlates with disease progression. Gain- and loss-of-function studies revealed that miR-21 promoted cell proliferation and migration of ARPE-19 cells without affecting EMT-related gene expression. Together, our studies have identified miR-21 as a potential disease-modifying miRNA in the vitreous humor that is involved in the development of retinal fibrosis and may be a novel marker of PVD

Effects of intravitreal injection of ranibizumab and aflibercept for branch retinal vein occlusion on the choroid: a retrospective study

Abstract Background Macular edema is found in more than half of branch retinal vein occlusion (BRVO) cases, leading to visual loss in most of these cases. Intravitreal injection of anti-vascular endothelial growth factor is currently the standard treatment for macular edema due to BRVO (BRVO-ME). The difference in the effects of aflibercept and ranibizumab on the choroid in BRVO-ME is unknown. Therefore, we analyzed the effects of intravitreal injection of ranibizumab and aflibercept on BRVO-ME. Methods We retrospectively observed changes in choroidal thickness in the subfoveal region in 36 patients with BRVO-ME who visited the Department of Ophthalmology at the Juntendo University Urayasu Hospital. The patients were treated with intravitreal injection of aflibercept or ranibizumab and followed up for 12 months or more. Results The observed point bifurcated into the affected and non-affected sides 500 μm from the fovea. The central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) were 564.2 ± 268.5 μm and 228.8 ± 50.1 μm, respectively, in the ranibizumab group (16 patients, 16 eyes) and 542.4 ± 172.5 μm and 246.1 ± 59.1 μm, respectively, in the aflibercept group (20 patients, 20 eyes). The changes in CMT at 12 months were 324.0 ± 262.6 μm and 326.55 ± 187.2 μm in the ranibizumab and aflibercept groups, respectively, with no significant difference (p = 0.97). Similarly, the changes in SFCT over 12 months were not significant between the groups (ranibizumab, 41.9 ± 33.0 μm; aflibercept, 43.8 ± 43.8 μm, p = 0.89). Conclusion The effects of ranibizumab and aflibercept on choroidal thickness in BRVO-ME were the same regardless of the site. Although BRVO is a retinal disease, we hope that we can further explore the mechanism of BRVO-ME by observing changes in the choroid in the future

Effects of Secreted Mast Cell Mediators on Retinal Pigment Epithelial Cells: Focus on Mast Cell Tryptase

Numerous mast cells are present in the choroid, but the effects of mast cell mediators on retinal pigment epithelial (RPE) cells are not well understood. We investigated the influence of mast cell mediators on RPE cells in vitro, focusing on tryptase. Expression of receptors was examined by the reverse transcription polymerase chain reaction. We also assessed production of interleukin 8 and vascular endothelial growth factor (VEGF) after RPE cells were stimulated with mast cell mediators by using an antibody array and enzyme-linked immunosorbent assay. Furthermore, we investigated the influence of tryptase on RPE cell migration and integrity by the scratch assay and the transepithelial resistance. RPE cells expressed protease-activated receptor 2 (PAR2), histamine receptor 1, tumor necrosis factor-α (TNF-α) receptor 1, and CCR 1, 3, 4, 8, and 11. Tryptase, PAR2 agonists, histamine, and TNF-α all enhanced interleukin 8 production by RPE cells, while only tryptase enhanced VEGF production. Tryptase also enhanced expression of phosphorylated extracellular signal-regulated kinases 1/2, resulting in increased migration of RPE cells. However, tryptase did not alter epithelial integrity or the expression of zonula occludens-1 and junctional adhesion molecule-A by RPE cells. Mast cell mediators, especially tryptase, may influence RPE cell inflammation

Factors Affecting a Short-Term Response to Anti-VEGF Therapy in Diabetic Macular Edema

Diabetic macular edema (DME) is a common cause of visual impairment in patients with diabetes. Although intravitreal anti-vascular endothelial growth factor (VEGF) injections were efficacious in clinical trials, several patients exhibited a poor response. This study aimed to compare clinical features between patients who were susceptible to intravitreal anti-VEGF injections for DME and those who were not. A single-center, retrospective study of 102 such patients was conducted (123 eyes; mean ± standard deviation age, 63.4 ± 10.8 years; 57.8% males). Systemic and ocular data, assessed at baseline and after a month, were compared between good (>20% decrease in central macular thickness (CMT)) and poor (≤20% decrease in CMT) responders using the Mann–Whitney U test/Fisher’s exact test. Eighty-one eyes (65.9%) were good responders. The glycosylated hemoglobin level was higher (p = 0.011) in poor (7.5% ± 0.94%) than in good (7.04% ± 1.19%) responders. The foveal avascular zone was larger (p = 0.0003) in poor (0.67 ± 0.33 μm2) than in good (0.47 ± 0.23 μm2) responders. The number of microaneurysms in the pericapillary network was higher (p = 0.0007) in poor (2.7 ± 2.2) than in good (1.4 ± 2.0) responders. Baseline glycemic control and macular ischemia may be associated with the short-term response to intravitreal anti-VEGF injections

Effect of miR-21 expression on epithelial-mesenchymal transition (EMT)-related gene expression during TGF-β2-induced EMT of ARPE-19 cells.

<p>(A, B, and C) Results of qPCR analyses of fibronectin, αSMA, and N-cadherin mRNA expression in miR-21 mimic- or inhibitor-transfected ARPE-19 cells in the presence or absence of TGF-β2. Fold changes in expression levels of fibronectin (A), αSMA (B), and N-cadherin (C) mRNAs in miR-21 mimic-transfected ARPE-19 cells were determined relative to the untransfected control. NC, negative control; αSMA, alpha smooth muscle actin; EMT, epithelial-mesenchymal transition. ***p < 0.001; **p < 0.01; *p < 0.05; n.s; not significant.</p

Effect of miR-21 expression on cell proliferation of ARPE-19 cells.

<p>(A, B) Results of quantitative (q)PCR analyses of miR-21 in miR-21 mimic- or inhibitor-transfected ARPE-19 cells. Fold changes in expression levels of miR-21 in miR-21 mimic-transfected ARPE-19 cells were determined relative to the negative control mimic-transfected cells (A). Expression level of miR-21 in miR-21 inhibitor-transfected ARPE-19 cells in the presence or absence of TGF-β2 was calculated by comparing with negative control inhibitor-transfected cells (B). (C) Effect of miR-21 mimic or miR-21 inhibitor transfection on GFP reporter gene expression of CMV-EGFP or CMV-EGFP-3′ UTR miR-21-target reporter plasmid in ARPE19 cells. ARPE-19 cells were co-transfected with CMV-EGFP or CMV-EGFP-3′ UTR miR-21-target reporter plasmid, together with miR-21 mimics or miR-21 inhibitor, as indicated. After 24 h, GFP expression was analyzed under the fluorescence microscope. All fluorescence images were taken at the same exposure time (1/15s). (D, E) The migration ability of miR-21 mimic and miR-21 inhibitor-treated ARPE-19 cells was examined using the wound healing assay. (D) Representative images of wound sealing of miR-21 mimic and miR-21 inhibitor-transfected cells cultured with or without TGF-β at 0 and 12 h. (E) Quantification of the wound healing assay. The figure shows the average percentage of wound closure ± SD. The transfection of the miR-21 mimic significantly increased cell migration of ARPE-19 cells without TGF-β stimulation, and transfection of miR-21 inhibitor inhibited TGF-β-induced enhanced migration. (F, G) Cell viability was measured with CCK-8 kits following the treatment of miR-21 mimic and miR-21 inhibitor for 12, 24, 48, 72, and 96 h (F). The miR-21 mimic treatment resulted in increased cell proliferation, and miR-21 inhibitor treatment resulted in decreased cell proliferation at 72 h (G). NC, negative control. ***p < 0.001; **p < 0.01; *p < 0.05.</p

Expression of miR-21 is induced by signaling and high glucose conditions in RPECs.

<p>(A, B, and C) Results of quantitative (q) PCR analyses of miR-21, miR-204, and let-7e levels in TGF-β-stimulated ARPE-19 cells. Fold changes in expression levels of miR-21 (A), miR-204 (B), and let-7e (C) in TGF-β-stimulated ARPE-19 cells were determined relative to the unstimulated control cells. (D) Results of qPCR analyses of TGF-β-induced expression of miR-21 in ARPE-19 cells under low or high glucose conditions. Fold changes in expression levels of miR-21 in TGF-β-stimulated ARPE-19 cells under low or high glucose culture conditions were determined relative to the unstimulated control cells. RPECs, retinal pigment epithelial cells; TGF-β, transforming growth factor-β; LG = low glucose; HG = high glucose. *<i>*p</i> < 0.01; *<i>p</i> < 0.05.</p