MicroRNA-145-5p targeting of TRIM2 mediates the apoptosis of retinal ganglion cells via the PI3K/AKT signaling pathway in glaucoma.

BACKGROUND: There is accumulating evidence to suggest that microRNAs (miRNAs) are associated with the progressive optic neuropathy including glaucoma. Apoptosis of retinal ganglion cells (RGCs) is a hallmark of glaucoma. The present study focused on the effects of miR-145-5p on RGC apoptosis in glaucoma. METHODS: We established a glaucoma rat model by intraocular injection of N-methyl-d-aspartic acid (NMDA). RGCs were isolated from newborn rats and treated with NMDA. Hematoxylin and eosin staining was performed to detect morphological changes in the retinas of rats. The expression of miR-145-5p and tripartite motif-containing 2 (TRIM2) in RGCs was measured by RT-qPCR. The viability of RGCs was measured by MTT assay. Flow cytometry analysis and TUNEL assays were conducted to assess the apoptosis of RGCs. The interaction between miR-145-5p and TRIM2 was investigated using a luciferase reporter assay. RESULTS: Rats injected with NMDA showed a thinner ganglion cell layer (GCL) and inner plexiform layer (IPL) as well as increased expression of miR-145-5p. Silencing of miR-145-5p significantly increased the GCL and IPL in the glaucoma rat model. Moreover, miR-145-5p expression was upregulated in RGCs ex vivo in response to NMDA. Silencing of miR-145-5p promoted cell viability and suppressed apoptosis in NMDA-treated RGCs. Mechanistically, miR-145-5p targeted the TRIM2 3' untranslated region to suppress its expression. TRIM2 was upregulated in NMDA-treated RGCs and protected RGCs against NMDA-induced apoptosis. Furthermore, miR-145-5p suppressed the PI3K/AKT pathway by downregulating TRIM2 in NMDA-treated RGCs. CONCLUSIONS: Suppression of miR-145-5p inhibited the apoptosis of RGCs via TRIM2-mediated activation of the PI3K/AKT signaling pathway in NMDA-induced glaucoma.

SNHG3 cooperates with ELAVL2 to modulate cell apoptosis and extracellular matrix accumulation by stabilizing SNAI2 in human trabecular meshwork cells under oxidative stress.

Glaucoma is the main reason for irreversible blindness, and pathological increased intraocular pressure is the leading risk factor for glaucoma. It is reported that trabecular meshwork cell injury is closely associated with the elevated intraocular pressure. The current study aimed to investigate the role of small nucleolar RNA host gene 3 (SNHG3) in human trabecular meshwork (HTM) cells under oxidative stress. A series of experiments including real-time quantitative polymerase chain reaction, subcellular fractionation assay, western blot analysis, cell counting kit-8 assay, RNA pull down, flow cytometry analysis, and RNA immunoprecipitation assay were used to explore the biological function and regulatory mechanism of SNHG3 in HTM cells under oxidative stress. First, we observed that H2 O2 induced SNHG3 upregulation in HTM cells. Then, we found that SNHG3 silencing alleviated H2 O2 -induced oxidative damage in HTM cells. Moreover, snail family transcriptional repressor 2 (SNAI2) knockdown alleviated the oxidative damage induced by H2 O2 in HTM cells. Mechanistically, SNHG3 bound with ELAV like RNA binding protein 2 (ELAVL2) to stabilize SNAI2. Finally, SNAI2 overexpression counteracted the effect of SNHG3 silencing on H2 O2 -treated HTM cells. In conclusion, our results demonstrated that SNHG3 cooperated with ELAVL2 to modulate cell apoptosis and extracellular matrix accumulation by stabilizing SNAI2 in HTM cells under oxidative stress.

HDAC6 inhibitor Cay10603 inhibits high glucose-induced oxidative stress, inflammation and apoptosis in retinal pigment epithelial cells via regulating NF-κB and NLRP3 inflammasome pathway.

The present study aimed to investigate the effects of histone deacetylase 6 (HDAC6) inhibitor Cay10603 (Cay) on high glucose (HG)-stimulated human retinal pigment epithelium (RPE) cells and its underlying mechanisms. ARPE-19 cells were cultured under normal glucose (NG) or high glucose (HG) conditions. The results revealed that HDAC6 was upregulated in HG-stimulated ARPE-19 cells. Cay treatment caused a decrease in intracellular reactive oxygen species (ROS). The levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were reduced accompanied by increase in the activities of superoxide dismutase (SOD) and catalase (CAT) after treatment with Cay. Besides, Cay decreased the levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), IL-6 and monocyte chemoattractant protein-1 (MCP-1) in supernatant. Meanwhile, the apoptotic rate in Cay-treated ARPE-19 cells notably reduced, coupled with an upregulation in Bcl-2 expression and a downregulation in cleaved caspase-3 and cleaved caspase-9 expression. Cay decreased the expression of phospho (p)-NF-κB p65, p-IκB-α, NLRP3, cleaved caspase-1 and ASC while increased the expression of NF-κB p65 (cytoplasm). Taken together, these findings demonstrated that Cay suppressed HG-induced oxidative stress, inflammation and apoptosis via regulating NF-κB and NLRP3 inflammasome pathway in HG-induced ARPE-19 cells, suggesting that Cay might be a therapeutic agent for the treatment of diabetic retinopathy.

Association of n-3 polyunsaturated fatty acid intakes with juvenile myopia: A cross-sectional study based on the NHANES database.

Aim: Inflammation is involved in the development of myopia. n-3 polyunsaturated fatty acids (n-3 PUFAs) have vasodilating and anti-inflammatory effects, which may be involved in controlling myopia. It is of great significance to explore the relationship between n-3 PUFA intakes and juvenile myopia in order to control and alleviate myopia among teenagers through dietary intervention. Methods: Sociodemographic data, information of nutrient intakes, cotinine, PUFAs, and eye refractive status of 1,128 juveniles were extracted from the National Health and Nutrition Examination Survey (NHANES) database in this cross-sectional study. PUFAs contained total polyunsaturated fatty acid (TPFAs), alpha-linolenic acid, octadecatetraenoic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). Covariates were screened by comparison among groups of normal vision, low myopia, and high myopia. The association between n-3 PUFA intakes and the risk of juvenile myopia was evaluated using univariate and multivariate logistic regression analyses with odds ratios (ORs) and 95% confidence intervals (CIs). Results: Among the juveniles, 788 (70.68%) had normal vision, 299 (25.80%) had low myopia, and 41 (3.52%) had high myopia. There were significant differences in average EPA and DHA intakes among the three groups, and mean DPA and DHA intakes in the normal vision group were lower than those in the low myopia group (P < 0.05). After adjustment for age, gender, TPFAs, and cotinine, a high dietary intake of EPA (≥11 mg/1,000 kcal) in juveniles seemed to be associated with the risk of high myopia (OR = 0.39, 95% CI: 0.18-0.85), while no significant associations were identified between n-3 PUFA intakes and the risk of low myopia. Conclusion: A high dietary intake of EPA may be associated with a decreased risk of high myopia among juveniles. A further prospective study is needed to validate this observation.

Gastrodin protects retinal ganglion cells from ischemic injury by activating phosphatidylinositol 3-kinase/protein kinase B/nuclear factor erythroid 2-related factor 2 (PI3K/AKT/Nrf2) signaling pathway.

Glaucoma is a progressive optic neuropathy and improper treatment may cause irreversible damage to visual function. Gastrodin is an effective active substance extracted from Gastrodia elata and possesses antioxidant as well as anti-inflammatory properties. However, the therapeutic potential of gastrodin for retinal ischemia/reperfusion (I/R) injury remains unclear. We adopted oxygen and glucose deprivation/reoxygenation (OGD/R) to induce R28 cells with the aim of simulating glaucomatous neurodegeneration. CCK-8 analysis and TUNEL were applied for examining cell proliferation and apoptosis . In addition, RT-qPCR and ELISA were performed to test the releases of inflammatory factors in cells . Related indicators of intracellular oxidative stress and ROS production were detected by corresponding kits. Moreover, western blot was applied to assay the expressions of PI3K/AKT/Nrf2 pathway-related proteins. OGD/R induction contributed to the decreased cell viability and reduced Bcl-2 protein expression, while the protein contents of Bax, Cyto-C, c-caspase 9 and c-PARP as well as ROS production were ascended. The co-treatment of hypoxia and gastrodin greatly improved R28 cell viability but effectively suppressed cell apoptosis, ROS level and the releases of OGD/R-induced inflammatory factors as well as oxidative stress. In addition, OGD/R stimulation reduced Nrf2, accompanied by a decrease in the phosphorylation levels of PI3K and AKT. Gastrodin significantly promoted the activation of PI3K/AKT/Nrf2 signaling pathway in R28 cells, which was then counteracted by PI3K/AKT inhibitors. In conclusion, the present study suggested that gastrodin has a protective effect on OGD/R-induced R28 cell injury, which is achieved through the activation of the PI3K/AKT/Nrf2 signaling pathway.

Trimetazidine mitigates high glucose-induced retinal endothelial dysfunction by inhibiting PI3K/Akt/mTOR pathway-mediated autophagy.

Trimetazidine (TMZ), as a metabolic regulator, has been widely testified to exhibit positive therapeutic effects on various disease models, but its role in diabetic retinopathy has not been reported. Therefore, this study was designed with the purpose of exploring the effects of TMZ on high-glucose (HG)-induced retinal endothelial dysfunction and its underlying mechanism. To establish DR model in vitro, 30 mM glucose was applied to induce human retinal endothelial cells (HRECs). Cell proliferation, invasion, and migration were examined by means of Cell Counting Kit-8, transwell, and wound healing assays, respectively. The tubule formation experiment was used to test the tubulogenesis ability and fluorescein isothiocyanate (FITC)-albumin was utilized to measure the permeability of monolayer HRECs. In addition, immunofluorescence and Western blot were employed to detect protein expression. Compared with the HG-induced group, TMZ concentration dependently inhibited the proliferation, migration, and angiogenesis of HG-induced HRECs, decreased the permeability of monolayer HRECs, and increased the protein expression levels of Claudin-5 and VE-cadherin. In addition, TMZ intervention increased the expression of p-PI3K, p-AKT, and p-mTOR but decreased the expression of LC3I, LC3II, and Beclin 1, which were then partially reversed by P13 K inhibitor (LY294002). Moreover, the autophagy agonist rapamycin (RAPA) was also testified to reverse the inhibitory effects of TMZ on the proliferation, migration, and angiogenesis of HG-induced HRECs. In summary, TMZ inhibited excessive autophagy by activating PI3K/Akt/mTOR pathway, thereby improving retinal endothelial dysfunction induced by HG.

Genetic Association Study Revealed Three Loci Were Associated Risk of Myopia Among Minors.

BACKGROUND: Myopia has raised a predominant public concern among minors. A recent genome-wide association study (GWAS) identified six novel loci in Asian adults. Whether these genetic loci works for myopia in minors remains unknown and worthy of exploration. METHODS: In order to validate the findings, here we performed a case-control study (600 myopia minors, 110 high myopia (HM) minors, and 800 non-myopia minors as controls) utilizing the TaqMan single nucleotide polymorphism (SNP) genotyping assays. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) was adopted. RESULTS: The median ages in controls, myopia, and HM were 15.1, 15.0, and 15.1, respectively, while the means ± standard deviations for them were 0.32±0.41, - 3.2 ±1.6, and -9.8±2.2, respectively. We found rs2246661 (allelic OR: 1.29; 95% CI: 1.09-1.52; P =0.003), rs74633073 (allelic OR: 1.41; 95% CI: 1.12-1.78; P =0.004), and rs76903431 (allelic OR: 1.42; 95% CI: 1.11-1.81; P =0.005) were significantly associated with increased risk of myopia. Rs2246661 was also significantly associated with increased risk of HM in minors (OR: 1.37; 95% CI: 1.02-1.84; P =0.035). CONCLUSION: We identified three loci contributed to myopia in minors and these findings gave new insight into the genetic susceptibility mechanisms of myopia at the molecular level.