Mini-αA Upregulates the miR-155-5p Target Gene CDK2 and Plays an Antiapoptotic Role in Retinal Pigment Epithelial Cells during Oxidative Stress.

Background: Age-related macular degeneration (AMD) is the leading cause of serious vision loss in the elderly. Regulating microRNA (miRNA) gene expression offers exciting new avenues for treating AMD. This study aimed to investigate whether miRNAs and their target genes play an antiapoptotic role during oxidative stress-induced apoptosis of retinal pigment epithelial (RPE) cells via mini-αA. Methods: ARPE-19 cells were treated with 3.5 mM NaIO3 for 48 h to establish a retinal degeneration model. Cells were treated with mini-αA (10, 15, and 20 µM) for 4 h. miR-155-5p was knocked down and overexpressed. Cell viability and apoptosis were measured using the Cell Counting Kit-8 assay and flow cytometry, respectively. The reactive oxygen species level was detected by flow cytometry. miR-155-5p target genes were predicted via bioinformatics. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed for miR-155-5p target genes. A quantitative real-time polymerase chain reaction was performed to detect miRNAs and cell cycle-related target genes. Western blotting was performed to measure the levels of apoptotic pathway genes encoding Bcl-2, Bax, cleaved caspase-3, and cyclin-dependent kinase 2 (CDK2). Dual-luciferase reporter gene assay was performed to verify the targeted binding relationship between miR-155-5p and CDK2. Results: NaIO3 can induce oxidative damage and promote apoptosis. Conversely, mini-αA had inhibitory effects and could reverse the oxidative damage and apoptosis triggered by NaIO3 in the retinal degeneration model. The expression of miR-155-5p was upregulated in cells treated with NaIO3 and was downregulated after mini-αA treatment. Furthermore, miR-155-5p can target the following cell cycle-related and proliferation-related genes: CDK2, CDK4, CCND1, and CCND2. Moreover, our study indicated that miR-155-5p was involved in the antioxidative damage and antiapoptotic effects of mini-αA via CDK2 regulation. Conclusions: miR-155-5p promotes the antioxidative damage and antiapoptotic effects of mini-αA during oxidative stress-induced apoptosis of RPE cells via CDK2 regulation. This study provides a new therapeutic target for AMD.

Characteristics of Preferred Retinal Locus in Eyes with Central Vision Loss Secondary to Different Macular Lesions.

OBJECTIVE: Preferred retinal locus (PRL) training has been applied to low-vision rehabilitation for patients with central vision loss (CVL). This study aimed to explore the characteristics of a natural PRL in eyes with different macular lesions. The data may be useful in customizing training programs. METHODS: A total of 72 eyes with CVL were included and assigned into two groups. In group A, 29 eyes diagnosed with macular holes featured relatively sharp borders and small areas of lesions. In group B, 44 eyes showed lesions characterized by irregular borders and large areas. The PRL location relative to a scotoma in the retina, fixation stability, and the average threshold surrounding the PRL were determined and compared between the two groups. RESULTS: In group A, the PRL was located above in 48.28%, below in 27.59%, left in 62.07%, right in 31.03%, and inside in 3.45% of the eyes. In group B, the PRL was located above in 39.53%, below in 4.65%, left in 44.19%, right in 6.98%, and inside in 27.91% of eyes. The amount of retinal displacement occurring within 1° from an initial reference point (P< .05) and the 95% bivariate contour ellipse area (P< .05) in group A were respectively higher and lower than those in group B. However, the average thresholds around the PRLs in the two groups showed no significant difference (P > .05). CONCLUSIONS: A PRL to the left of or above a scotoma tends to develop to avoid the right and inferior field defect, regardless of the scale and boundary of lesions. Although light sensitivity around a PRL shows no relation to lesion features, fixation stability is worse in irregular and large lesions.

Myopic Retinal Changes Screening: Comparison of Sensitivity and Specificity among 15 Combinations of Ultrawide Field Scanning Laser Ophthalmoscopy Images.

AIM: The objective of the study was to investigate the evaluation indices (diagnostic test accuracy and agreement) of 15 combinations of ultrawide field scanning laser ophthalmoscopy (UWF SLO) images in myopic retinal changes (MRC) screening to determine the combination of imaging that yields the highest evaluation indices in screening MRC. METHODS: This is a retrospective study of UWF SLO images obtained from myopes and were analyzed by 2 retinal specialists independently. Five field UWF SLO images that included the posterior (B), superior (S), inferior (I), nasal (N), and temporal (T) regions were obtained for analysis and its results used as a reference standard. The evaluation indices of different combinations comprising 1 to 4 fields of the retina were compared to determine the abilities of each combination screens for MRC. RESULTS: UWF SLO images obtained from 823 myopic patients (1,646 eyes) were included for the study. Sensitivities ranged from 50.0 to 98.9% (95% confidence interval (CI), 43.8-99.7%); the combinations of B + S + I (97.3%; 95% CI, 94.4-98.8%), B + T + S + I (98.5%; 95% CI, 95.9-99.5%), and B + S + N + I (98.9%; 95% CI, 96.4-99.7%) ranked highest. Furthermore, the combinations of B + S + I, B + T + S + I, and B + S + N + I also revealed the highest accuracy (97.7%; 95% CI, 95.1-100.0, 98.6; 95% CI, 96.7-100.0, 98.8; 95% CI, 96.9-100.0%) and agreement (kappa = 0.968, 0.980, and 0.980). For the various combinations, specificities were all higher than 99.5% (95% CI, 99.3-100.0%). CONCLUSIONS: In our study, screening combinations of B + S + I, B + T + S + I, and B + S + N + I stand out with high-performing optimal evaluation indices. However, when time is limited, B + S + I may be more applicable in primary screening of MRC.

MiR-1246 promotes anti-apoptotic effect of mini-αA in oxidative stress-induced apoptosis in retinal pigment epithelial cells.

BACKGROUND: Geographic atrophy (GA) is a late-stage symptom of an age-related macular degeneration (AMD), characterized by the loss of retinal pigment epithelial (RPE) cells and photoreceptor functions. Despite being a major cause of blindness in individuals of 65 years of age and older, some forms of AMD, including GA, still lack targeted treatment. Our previous study demonstrated that mini-αA peptide, which contains the functional site of αA-crystallin, protected RPE cells from NaIO3 -induced apoptosis. METHODS: To further investigate the underlying mechanism, we applied next-generation sequencing analysis to identify miR-1246 as a putative mediator of mini-αA protective function. To investigate the role of miR-1246 in RPE cell apoptosis, a stable miR-1246-low-expression cell line was established by using miR-1246 inhibitor. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to investigate the proliferation of RPE cells, mRNA and miR-1246 expression were detected by the quantitative reverse transcriptase-polymerase chain reaction. RESULTS: We have further identified caspase-3 and caspase-14 as molecular targets of miR-1246 involved in regulation of apoptosis in NaIO3 -incubated cells. Interestingly, disruption of miR-1246 expression enhanced anti-apoptotic effect of mini-αA on RPE cells during oxidative stress. CONCLUSIONS: Our results provide a mechanistic basis for evaluation of miR-1246 as a new candidate target for the clinical treatment of AMD.

Air tamponade in retinal detachment surgery followed by ultra-widefield fundus imaging system.

AIM: To report the surgical result of pars plana vitrectomy (PPV) with air tamponade for rhegmatogenous retinal detachment (RRD) by ultra-widefield fundus imaging system. METHODS: Of 25 consecutive patients (25 eyes) with fresh primary RRD and causative retinal break and vitreous traction were presented. All the patients underwent PPV with air tamponade. Visual acuity (VA) was examined postoperatively and images were captured by ultra-widefield scanning laser ophthalmoscope system (Optos). RESULTS: Initial reattachment was achieved in 25 cases (100%). The air volume was >60% on the postoperative day (POD) 1. The ultra-widefield images showed that the retina was reattached in all air-filled eyes postoperatively. The retinal break and laser burns in the superior were detected in 22 of 25 eyes (88%). A missed retinal hole was found under intravitreal air bubble in 1 case (4%). The air volume was range from 40% to 60% on POD 3. A double-layered image was seen in 25 of 25 eyes with intravitreal gas. Retinal breaks and laser burns around were seen in the intravitreal air. On POD 7, small bubble without effect was seen in 6 cases (24%) and bubble was completely disappeared in 4 cases (16%). Small oval bubble in the superior area was observed in 15 cases (60%). There were no missed and new retinal breaks and no retinal detachment in all cases on the POD 14 and 1mo and last follow-up. Air disappeared completely on a mean of 9.84d postoperatively. The mean final postoperative best-corrected visual acuity (BCVA) was 0.35 logMAR. Mean final postoperative BCVA improved significantly relative to mean preoperative (P<0.05). Final VA of 0.3 logMAR or better was seen in 13 eyes. CONCLUSION: PPV with air tamponade is an effective management for fresh RRD with superior retinal breaks. The ultra-widefield fundus imaging can detect postoperative retinal breaks in air-filled eyes. It would be a useful facility for follow-up after PPV with air tamponade. Facedown position and acquired visual rehabilitation may be shorten.