CircSTRBP contributes to H2O2-induced lens epithelium cell dysfunction through increasing NOX4 mRNA stability by recruiting IGF2BP1.

Previous studies have shown that the development of age-related cataract (ARC) is involved in lens epithelium dysfunction, which is associated with abnormally expressed circular RNAs (circRNAs). The current work aims to probe the role of circSTRBP (hsa_circ_0088,427) in hydrogen peroxide (H2O2)-induced lens epitheliums. Lens epithelium tissues were harvested from ARC or normal subjects (n = 23). CircSTRBP, spermatid perinuclear RNA binding protein (STRBP), and nicotinamide adenine dinucleotide phosphate oxidase subunit 4 (NOX4) levels were measured using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell proliferation, cycle progression, and apoptosis were assessed using 5-ethynyl-2'-deoxyuridine (EdU), Cell Counting Kit-8 (CCK-8), and flow cytometry assays. Caspase 3 activity, reactive oxygen species (ROS), malondialdehyde (MDA), and Glutathione peroxidases (GSH-PX) levels were detected using corresponding kits. NOX4 protein level was determined using Western blot. The interaction between insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) and circSTRBP or NOX4 was assessed through RNA immunoprecipitation (RIP). CircSTRBP and NOX4 abundances were increased in lens epithelium samples from ARC patients and H2O2-treated SRA01/04 cells. CircSTRBP knockdown might abolish H2O2-triggered SRA01/04 cell proliferation repression and apoptosis and oxidative stress promotion. In mechanism, circSTRBP is bound with IGF2BP1 and improves the stability and expression of NOX4 mRNA in SRA01/04 cells. CircSTRBP facilitated H2O2-induced SRA01/04 cell apoptosis and oxidative stress through by enhancing NOX4 mRNA stability via recruiting IGF2BP1, providing novel insights for ARC progression and treatment.

Aggravation of retinal hard exudates after intravitreal anti-vascular endothelial growth factor therapy for cystoid macular edema and the risk factors: a retrospective study.

BACKGROUND/AIMS: To evaluate retinal hard exudates (HEs) progression in patients with cystoid macular edema (CME) secondary to diabetic retinopathy (DR) or branch retinal vascular occlusion (BRVO) after intravitreal injections of ranibizumab (IVR) treatment and identify the risk factors for the deterioration of HEs. METHODS: This retrospective study enrolled 288 eyes with center-involving CME secondary to DR or BRVO from 288 patients (one eye per patient). All patients were treated with three loading doses of ranibizumab intravitreally at a monthly interval. The morphologic features of HEs were observed, and the HEs areas were quantified using a semi-automatic method at baseline, 1 month after the first dose of IVR and 1 month after the third dose of IVR therapy. HEs progression was defined as having a > =2-grade increase in the HEs severity scale. The best-corrected vision acuity (BCVA) and alterations in HEs areas were compared between DR and BRVO groups. And logistic regression analyses were used to identify the risk factors for HEs exacerbation. RESULTS: Morphological changes of retinal HEs occurred in all eyes after IVR therapy, although HEs area was not significantly changed in some eyes. DR group has a higher percentage of eyes with progressed HEs area than the BRVO groups (34.9% vs. 21.8%, P = 0.019) 1 month after the first dose of IVR. Both DR and BRVO groups had a decreased percentage of enlarged HEs 1 month after the third injection, but the DR group is still higher than the BRVO group (17.1% vs. 8.4%, P = 0.027). At baseline, there was no correlation between VA and HEs areas. After the first and third doses of IVR, there still was no consistent correlation between HEs severity and change in VA over time. Furthermore, CME with subretinal fluid (SRF) is associated with a higher risk of HEs progression (P = 0.001). Long CME duration and high serum low-density lipoprotein cholesterol (LDL-C) level were identified as risk factors for HEs progression following IVR treatment in both univariable and multivariable regression analyses (Odds ratio (OR) = 1.88, P = 0.012 and OR = 1.14, P = 0.021, respectively). CONCLUSIONS: Alterations in the area of retinal HEs are widely observed after IVR treatment for CME. The eyes with CME secondary to DR have a higher percentage of progressed HEs than the BRVO eyes. DME with SRF, extended duration of CME, and high LDL-C level are potential risk factors of deteriorated HEs after IVR treatment.

[Expression of thioredoxin-2 in human lens epithelial cells with oxidative damage and its significance].

OBJECTIVE: To explore whether thioredoin-2 (Trx-2) is involved in the development of cataract and to study the effect of Trx-2 on hydrogen peroxide (H2O2)-induced injury in human lens epithelial cells.
 Methods: A total of 10 volunteers (removing the lens due totraumatism) and 30 patients received phacoemulsification (age more than 60 years) were selected. The expression of Trx-2 protein in lens epithelial cells from cataract patients and volunteers were detected by the immunohistochemical streptavidin-peroxidase (SP) method. SRA01/04 cells were cultured and were divided into six groups according to different treatment: a control group, H2O2-treated groups at 20, 50 or 100 µmol/L, a negative control group (transfected with pCMV6 plasmid plus 100 µmol/L H2O2), and a Trx-2 overexpression group (transfected with pCMV6-Trx-2 plasmid plus 100 µmol/L H2O2). Methyl thiazolyltetrazolium (MTT) assay and flow cytometry was performed to measure the cell viability and apoptosis for SRA01/04 cells, respectively. The activities of superoxide dismutase (SOD) and catalase (CAT), the content of glutathione (GSH) and malondialdehyde (MDA) in human lens epithelial cells were measured via chemical chromatometry. Western blot was used to measure the protein levels of Trx-2, B-cell lymphoma 2 protein (Bcl-2), Bcl-2 associated X protein (Bax) and caspase-3.
 Results: Compared with the volunteers, the expression of Trx-2 was significantly decreased in lens epithelial cells in patients with cataract (P<0.05). Compared with the control group, the expression of Trx-2 protein in the 20, 50 or 100 µmol/L H2O2 groups was decreased (all P<0.05). Compared with the control group, the cell survival rates were decreased in the 100 µmol/L H2O2 group and the negative control group (both P<0.05), along with enhanced apoptotic rates, inhibited cellular SOD activities and CAT activities, reduced GSH contents, augmented MDA contents, down-regulated Trx-2 and Bcl-2 expression and up-regulated Bax and caspase-3 expression (all P<0.05). Compared with the negative control group, the cell survival rate was increased in the Trx-2 overexpression group (P<0.05), along with suppressed apoptosis, increased SOD activities and CAT activities, elevated GSH contents, decreased MDA content, up-regulated Trx-2 and Bcl-2 expression and down-regulated Bax and caspase-3 expression (P<0.05).
 Conclusion: Trx-2 might be involved in the apoptosis of lens epithelial cells in patients with cataract. The overexpression of Trx-2 obviously attenuated H2O2-induced injury of human lens epithelial cells, which might be associated with the inhibition of H2O2-mediated oxidative stress.

Suppression of Disheveled-Axin Domain Containing 1 (DIXDC1) by MicroRNA-186 Inhibits the Proliferation and Invasion of Retinoblastoma Cells.

Recent evidence shows that Disheveled-Axin domain containing 1 (DIXDC1) is dysregulated in various cancers. However, the role of DIXDC1 in retinoblastoma (RB) remains unclear. In this study, we aimed to investigate the biological function of DIDXDC1 in RB and the way in which its expression is regulated by microRNAs (miRNAs). We found that DIXDC1 expression was significantly upregulated in RB cell lines. The silencing of DIXDC1 by small interfering RNA (siRNA) significantly inhibited the proliferation, invasion, and Wnt signaling in RB cell lines. Interestingly, DIXDC1 was identified as a target gene of miR-186. The expression of DIXDC1 was negatively regulated by miR-186, and DIXDC1 expression was inversely correlated with miR-186 expression in RB clinical specimens. Overexpression of miR-186 inhibited the proliferation, invasion, and Wnt signaling in RB cell lines. Moreover, overexpression of DIXDC1 markedly reversed the antitumor effect of miR-186. Overall, our results reveal that DIXDC1 functions as a potential oncogene in RB, and inhibiting DIXDC1 by miR-186 suppresses the proliferation and invasion of RB cell lines. Our study suggests that DIXDC1 and miR-186 may serve as novel therapeutic targets for the treatment of RB.