FOXO4 mediates resistance to oxidative stress in lens epithelial cells by modulating the TRIM25/Nrf2 signaling.

Oxidative stress damage to the lens is a key factor in most cataracts. Forkhead box O 4 (FOXO4), a member of the forkhead box O family, plays a pivotal role in oxidative stress. FOXO4 is upregulated in lens of age-related cataract patients, but its role in cataract has not been elucidated. Herein, we investigated the role and mechanism of FOXO4 during oxidative stress damage in lens epithelial cells. H2O2 treatment enhanced FOXO4 expression in HLEpiC cells. Short hairpin RNAs mediated FOXO4 silence aggravated H2O2-induced cell apoptosis. In addition, upon H2O2 exposure, silencing of FOXO4 reduced SOD and CAT activities, as well as increased intracellular MDA and ROS levels. FOXO4 silencing also inhibited Nrf2 nuclear translocation, followed by reducing the expressions of Nrf2-governed antioxidant genes HO-1 and NOQ-1. Exogenous overexpression of FOXO4 was also involved in this study and exhibited opposite effects of FOXO4-silencing. Mechanistically, FOXO4 directly bound the promoter of TRIM25 and regulated its transcription, thereby activating the Nrf2 signaling. Taken together, in the condition of oxidative stress, the expression of FOXO4 showed a compensatory upregulation and it exhibited an anti-oxidative effect by modulating the transcription of TRIM25, thus activating the Nrf2 signaling. The FOXO4/TRIM25/Nrf2 axis may be associated with the pathological mechanisms of cataract.

Ferrostatin-1 alleviates tissue and cell damage in diabetic retinopathy by improving the antioxidant capacity of the Xc--GPX4 system.

Diabetic retinopathy (DR) is a common microvascular complication leading to a high blindness rate among patients with diabetes. Ferroptosis is a type of cell death caused by the accumulation of iron-dependent lipid peroxides. Studies have shown that ferroptosis plays an important role in DR. The rat model of DR was constructed and treated with Ferrostatin-1 (Ferr-1). Haematoxylin and eosin (HE) were used to detect the degree of retinopathy. Oxidative stress levels were detected by ELISA. Perl's staining was used to detect iron deposition in retinal tissues. Ferritin levels were measured by ELISA. The expression of GPX4 was detected by immunohistochemistry (IHC). GSH/GSSG kit was used to detect the content and proportion of reduced/oxidized glutathione. Western blot was used to detect the expression of ferroptosis-related proteins. TUNEL assay was used to detect cell apoptosis. The expression of GSDMD was detected by fluorescence in situ hybridization (FISH). Western blot was used to detect the expression of apoptosis and pyroptosis-related proteins. Then, high glucose (HG)-induced retinal epithelial cell line ARPE-19 was treated by Erastin (ferroptosis activator) and Ferr-1. CCK-8, ELISA, western blot, flow cytometry, and immunofluorescence (IF) staining were used to detect oxidative stress levels, ferroptosis and cell damage. The mechanism was further explored by adding ferroptosis agonist Erastin. In vitro and in vivo results showed that oxidative stress was increased in DR model, resulting in ferroptosis and tissue or cell damage. After administration of Ferr-1, the antioxidant capacity was improved, ferroptosis levels were reduced and tissue or cell damage was alleviated. In vitro results showed that Ferr-1 reversed the impacts of Erastin on oxidative stress, ferroptosis, and cell damage in HG-induced ARPE-19 cells. Ferr-1 alleviated tissue and cell damage by improving the antioxidant capacity of the Xc--GPX4 system.

Construction of Hyaluronic Acid-CeO2 Conjugated Composite Nanoparticles and Their Activity Efficiency in Diabetic Retinopathy Alleviation.

We developed an effective nanoparticle-biomaterial in alleviating diabetic retinopathy (DR), hyaluronic acid (HA)-CeO2, composed mainly of CeO2 and HA. To demonstrate its anti-DR capacity, retinal cells from a B6/J mouse model were used to compare the efficiency of PEI-CeO2 and HA-CeO2. We investigated the transport performance, histolysis, immune cell infiltration, angiogenesis, and hyperemia induced by the transport system. The structural integrity, microvascular apoptosis, and superoxide and peroxide concentrations in the retina were measured to evaluate the clinical efficacy of CeO2. The infiltration efficiency of HA-CeO2 was higher than that of PEI-CeO2. Lower levels of foreign body reaction were evident for HA-CeO2 with less histolysis, immune cell infiltration, angiogenesis, and hyperemia. The clinical efficacy of HA-CeO2 in terms of preservation of retinal structure and lowering of microvascular apoptosis and superoxide and peroxide concentrations was superior to those of PEI-CP. HA-CeO2 was shown to have significant antioxidation and anti-vascular injury capacity in a mouse model, and may be a potential compound nanodrug for DR treatment in the future.

Genetic investigation of 211 Chinese families expands the mutational and phenotypical spectra of hereditary retinopathy genes through targeted sequencing technology.

BACKGROUND: Hereditary retinopathy is a significant cause of blindness worldwide. Despite the discovery of many mutations in various retinopathies, a large number of patients remain genetically undiagnosed. Targeted next-generation sequencing of the human genome is a suitable approach for the molecular diagnosis of retinopathy. METHODS: We describe a cohort of 211 families from central China with various forms of retinopathy; 95 patients were investigated using multigene panel sequencing, and the other 116 with suspected Leber hereditary optic neuropathy (LHON) were tested by Sanger sequencing. The detected variation of targeted sequencing was verified by PCR-based Sanger sequencing. We performed a comprehensive analysis of the cases using sequencing data and ophthalmologic examination information. RESULTS: Potential causal mutations were identified in the majority of families with retinopathy (57.9% of 95 families) and suspected LHON (21.6% of 116 families). There were 68 variants of a certain significance distributed in 31 known disease-causing genes in the 95 families; 37 of the variants are novel and have not been reported to be related to hereditary retinopathy. The NGS panel solution provided a 45.3% potential diagnostic rate for retinopathy families, with candidate gene mutations of undefined pathogenicity revealed in another 12.6%of the families. CONCLUSION: Our study uncovered novel mutations and phenotypic aspects of retinopathy and demonstrated the genetic and clinical heterogeneity of related conditions. The findings show the detection rate of pathogenic variants in patients with hereditary retinopathy in central China as well as the diversity and gene distribution of these variants. The significance of molecular genetic testing for patients with hereditary retinopathy is also highlighted.

Decorin inhibits glucose-induced lens epithelial cell apoptosis via suppressing p22phox-p38 MAPK signaling pathway.

PURPOSE: To determine the effect of decorin on oxidative stress and apoptosis of human lens epithelial (HLE) cells under high glucose condition. METHODS: HLE cell line (HLEB3) was incubated in normal glucose (5.5 mM) or high glucose (60 mM) medium. Decorin (50 nM) was applied 2 hours before high glucose medium was added. Apoptosis detection was executed by flow cytometry and western blotting (analysis of bcl-2 and bax). Oxidative stress level was measured by the generation of reactive oxygen species (ROS), glutathione peroxidase (GSH) and superoxide dismutase (SOD). P38 mitogen-activated protein kinase (MAPK) phosphorylation, the expression of p22phox of HLE cells and human lens anterior capsules were detected by western blotting. Small interfering RNA transfection to p22phox and p38 MAPK was also carried out on HLEB3. RESULTS: High glucose caused HLE cells oxidative stress and apoptosis exhibiting the increase of apoptotic cells and ROS production and decrease of bcl-2/bax ratio, GSH/GSSG ration and SOD activity. P22phox and phospho-p38 MAPK were upregulated in high glucose treated HLEB3 cells. Knocking down p22phox or p38 by siRNAs can reduce high glucose induced cell apoptosis and oxidative stress level. Silencing p22phox by siRNA can downregulate the phosphorylation of p38 MAPK. Decorin can inhibit the apoptosis, oxidative stress level and the induction of p22phox and phospho-p38 of HLEB3 induced by high glucose. Furthermore, the expression of p22phox and p38 were found significantly increased in lens anterior capsules of diabetic cataract patients compared to that of normal age-related cataract patients. CONCLUSIONS: Results showed that p22phox-p38 pathway may be participated in high glucose induced lens epithelial cell injury, decorin may inhibit the high glucose induced apoptosis and oxidative stress injury by suppressing this pathway in part.

Long non-coding RNA ANRIL alleviates H2O2-induced injury by up-regulating microRNA-21 in human lens epithelial cells.

The accurate role of ANRIL in cataract is poorly understood. We aimed to reveal the effects of ANRIL on H2O2-treated HLECs, SRA01/04, as well as the regulatory mechanisms. Oxidative stress model of HLECs was induced by H2O2. Cell injury was evaluated according to cell proliferation, apoptosis and DNA damage using CCK-8 assay/flow cytometry and TUNEL assays/γH2AX staining. Expressions of ANRIL and miR-21 in HLECs were determined by RT-qPCR. The effects of miR-21, miR-34a and miR-122-5p inhibition as well as AMPK and ß-catenin on HLECs with ANRIL overexpression and H2O2 stimulation were analyzed. In vivo experiment was performed via RT-qPCR. H2O2 repressed proliferation and induced apoptosis or DNA damage in HLECs. Those alterations induced by H2O2 were attenuated by ANRIL overexpression. MiR-21 was positively regulated by ANRIL, and both of them were repressed in H2O2-induced HLECs and cataract patient tissues. Inhibition of miR-21 but not miR-34a or miR-122-5p reversed the effects of ANRIL on H2O2-treated HLECs. Phosphorylation of AMPK and expression of ß-catenin were increased by ANRIL via regulating miR-21. AMPK and ß-catenin affected beneficial function of ANRIL-miR-21 axis.Therefore, lncRNA ANRIL attenuated H2O2-induced cell injury in HELCs via up-regulating miR-21 via the activation of AMPK and ß-catenin.

In vitro inhibition of proliferation, migration and epithelial-mesenchymal transition of human lens epithelial cells by fasudil.

AIM: To study the potential role of fasudil as a treatment for posterior capsular opacification (PCO) of the human crystalline lens. METHODS: Human lens epithelial cells (HLECs; line SRA01/04) was exposed to transforming growth factor-ß2 (TGF-ß2) to induce the process of epithelial-mesenchymal transition (EMT). Fasudil was applied to the cell samples. Its effect on overall HLECs proliferation and migration was studied, as was its influence on EMT induction by TGF-ß2 using cell migration assay, MTT colorimetric assay and Western blot assay. RESULTS: Fasudil inhibited the proliferation of SRA01/04. Its effect was time- and concentration-dependent. The migration of SRA01/04 cells was significantly reduced 24-72h after fasudil treatment, and the half maximal inhibitory concentration (IC50) was 22.37 µmol/mL at 72h. Reversal of the elongated, fibroblast-like shape changes induced by TGF-ß2 in SRA01/04 cells was observed. Fasudil up-regulated the expression of Connexin43 protein and down-regulated the expression of α-SMA protein compared with the cells treated with TGF-ß2. Furthermore, when exposed to fasudil, the phosphorylation of Rho-associated protein kinase (Rock) and myosin light chain (MLC) could not be activated in the cell preparations. CONCLUSION: Fasudil suppresses the proliferation and migration of SRA01/04 cells, and inhibits the process of EMT induced by TGF-ß2. These results suggest that fasudil may serve as a therapeutic agent for PCO.

Experimental Study of the Biological Properties of Human Embryonic Stem Cell-Derived Retinal Progenitor Cells.

Retinal degenerative diseases are among the leading causes of blindness worldwide, and cell replacement is considered as a promising therapeutic. However, the resources of seed cells are scarce. To further explore this type of therapy, we adopted a culture system that could harvest a substantial quantity of retinal progenitor cells (RPCs) from human embryonic stem cells (hESCs) within a relatively short period of time. Furthermore, we transplanted these RPCs into the subretinal spaces of Royal College of Surgeons (RCS) rats. We quantified the thickness of the treated rats' outer nuclear layers (ONLs) and explored the visual function via electroretinography (ERG). It was found that the differentiated cells expressed RPC markers and photoreceptor progenitor markers. The transplanted RPCs survived for at least 12 weeks, resulting in beneficial effects on the morphology of the host retina, and led to a significant improvement in the visual function of the treated animals. These therapeutic effects suggest that the hESCs-derived RPCs could delay degeneration of the retina and partially restore visual function.