ASPP2 Upregulation as a Novel Approach to TGF-ß2-Induced Proliferative Vitreoretinopathy In Vivo and In Vitro.

PURPOSE: Proliferative vitreoretinopathy (PVR) can cause blindness and the pathogenesis is unclear. Transforming growth factor (TGF)-ß-induced epithelial-mesenchymal transition (EMT) of RPE cells is vital. P53 protein 2 (ASPP2) was previously reported to inhibit EMT in PVR rats, but the specific mechanism is unveiled. METHODS: TGF-ß was used to induce EMT in ARPE-19 cells, and evaluated by immunofluorescence and western blot. ARPE-19 cells were transfected with scrambled/ASPP2-lentivirus, followed by TGF-ß treatment. After that, alterations of EMT and autophagy were measured by western blot and transmission electron microscopy. Moreover, TGF-ß and ARPE-19 cells treated with scrambled/ASPP2-lentivirus were employed to establish the PVR model via intravitreal injection to SD rats, and retinal changes as well as EMT and autophagy activity were evaluated accordingly. RESULTS: ASPP2 expression was decreased during TGF-ß-induced EMT in ARPE-19 cells. In vitro, EMT and autophagy was activated by TGF-ß, which could be partly reversed by ASPP2 upregulation. In vivo, ASPP2 upregulation protected against structural and functional changes in PVR retinas. Additionally, expressions of EMT and autophagy markers in retinas were inhibited by ASPP2 upregulation. CONCLUSIONS: ASPP2 upregulation inhibited the EMT and autophagy process caused by TGF-ß in ARPE-19 cells. Correspondingly, upregulation of ASPP2 alleviated intraocular fibrosis and protected visual function in PVR rats.

The Beijing angle closure progression study: design and methodology.

Purpose: The purpose of this study is to summarize the design and methodology of a large-scale trial in northern China, the Beijing Angle Closure Progression Study (BAPS). This trial is designed to explore the 5-year incidence of primary angle-closure suspect (PACS) progressing to primary angle-closure (PAC) or primary angle-closure glaucoma (PACG) and to determine the possible risk factors of disease progression. Methods/design: The BAPS is a clinic-based, multicenter, noninterventional trial conducted on a sample of urban Chinese adults. Consecutive eligible patients who meet PACS diagnostic criteria will be recruited from eight participating centers, with the trial commencing on August 4, 2022. The target sample size is set at 825 subjects, with follow up planned for a minimum period of 5 years. Baseline examination will include presenting visual acuity, best corrected visual acuity, intraocular pressure (IOP), undilated slit-lamp biomicroscopy, stereoscopic evaluation of the optic disc, visual field test, optical coherence tomography evaluation of retinal nerve fiber layer, ultrasound biomicroscopy and IOLMaster. Questionnaires will also be used to collect detailed personal history. Patients are scheduled to visit the glaucoma clinic every 12 months and may visit the emergency room in case of acute attack of angle closure. Study endpoints include acute PAC episodes, elevated IOP, peripheral anterior synechiae, glaucomatous visual field defect, or glaucomatous abnormality of optic nerve. Discussion: The BAPS will provide data on the 5-year incidence of PACS progressing to PAC or PACG and determine the risk factors for disease progression. This study will also help redefine high-risk patients with PACS.

Relationship between BMI and risk of impaired glucose tolerance and impaired fasting glucose in Chinese adults: a prospective study.

BACKGROUND: Current studies in most Western countries have largely focused on body mass index (BMI) as an important risk factor for impaired glucose tolerance (IGT) and impaired fasting glucose (IFG), which have different pathophysiological bases. In people with obesity, the prevalence of IGT is higher and the prevalence of IFG is lower. The prevalence of IGT in the Asian population is higher than that in the white population, and the obesity rate in China is still increasing. However, few cohort studies explore the relationship between BMI and the incidence of IGT and IFG in China. We aimed to explore the relationship between BMI and the risk of IGT and IFG in Chinese adults and analyze the differences between them. METHODS: The baseline data were obtained from the 2010 China Chronic Disease and Risk Factor Surveillance, of which 20 surveillance sites were followed up from 2016 to 2017. Finally, in this study, a total of 5,578 studies were grouped into BMI categories of underweight (BMI < 18.5 kg/m2), normal weight (18.5-23.9 kg/m2), overweight (24.0-27.9 kg/m2), and obesity (≥ 28.0 kg/m2). We used the unconditional logistic regression model to analyze the relationship between BMI and the risk of IGT and IFG. RESULTS: During an average follow-up of 6.4 years, 562 developed IGT and 257 developed IFG. After age, gender, urban and rural areas, physical activity, family history of diabetes, hypertension, abdominal obesity, dyslipidemia, and other factors were adjusted, overweight increased the risk of IGT by 35% [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.08-1.70], and obesity increased the risk of IGT by 77% (OR 1.77, 95% CI 1.27-1.47). After the factors consistent with the above were adjusted, only obesity increased the risk of IFG by 122% (OR 2.22, 95% CI 1.39-3.54). CONCLUSIONS: In China, obesity is an important risk factor for IGT and IFG, and the risk of IGT increases during the overweight stage.

Upregulation of ASPP2 expression alleviates the development of proliferative vitreoretinopathy in a rat model.

AIM: To investigate whether upregulation of apoptosis-stimulating p53 protein 2 (ASPP2) expression could alleviate the development of proliferative vitreoretinopathy (PVR) in a rat model. METHODS: ASPP2-lentivirus or scrambled-lentivirus were transfected into ARPE-19 cells, followed with measurements of cell cytotoxicity by cell counting kit-8 assay. ASPP2 upregulation was confirmed by Western blotting and immunocytochemistry. Then ARPE-19 cells pretreated with ASPP2-lentivirus were intravitreally injected to Brown Norway rats to induce PVR models. PVR development and retinal function were evaluated by retinal photography and electroretinography, respectively. Finally, epithelial-mesenchymal transition as well as autophagy were investigated in rats' retinas via Western blotting. RESULTS: Protein expression of ASPP2 was significantly upregulated by ASPP2-lentivirus transfection in ARPE-19 cells. The development and progression of PVR were impeded significantly in rats with intravitreal injection of ARPE-19 cells pretreated with ASPP2-lentivirus. Accordingly, retinal functions were less affected and PVR grades were much lower in rats with ASPP2-lentivirus compared to scrambled-lentivirus treatment. Moreover, epithelial-mesenchymal transition and autophagy markers were decreased in the retinas of rats treated with ASPP2-lentivirus. CONCLUSION: ASPP2-lentivirus transfected to ARPE-19 cells mitigates the progression of PVR in rat models, which might be partly through reduced autophagy and attenuated epithelial-mesenchymal transition. ASPP2 might stand as a new approach for PVR treatment in the future.

Retraction Note to: A comparison of risk factors for age-related macular degeneration and polypoidal choroidal vasculopathy in Chinese patients.

The article "A comparison of risk factors for age-related macular degeneration and polypoidal choroidal vasculopathy in Chinese patients" has been retracted.

Anatomic Outcomes and Prognostic Factors of Vitrectomy in Patients with Primary Rhegmatogenous Retinal Detachment Associated with Choroidal Detachment.

PURPOSE: This study was undertaken to assess the associations between the anatomic outcomes of patients who underwent vitrectomy for rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD) and their preoperative variables. METHODS: A total of 175 patients with RRDCD who underwent vitrectomy in one eye were included in the analysis. The primary outcome measured was the retinal status after primary vitrectomy and at the end of follow-up. RESULTS: The retinal reattachment rate was 72.57% after primary surgery, and the final total reattachment rate was 89.14% after follow-up. Binary logistic regression analysis identified that the retinal reattachment rate after primary vitrectomy was significantly associated with older age (odds ratio = 1.03, p = 0.02), mild proliferative vitreoretinopathy (PVR) (PVR grade C vs. PVR grades A-B: odds ratio = 0.31, p = 0.04; PVR grade D vs. PVR grades A-B: odds ratio = 0.03, p < 0.01), and intravitreal steroid treatment (odds ratio = 4.60, p = 0.02), and that the final retinal reattachment rate was independently associated with older age (odds ratio = 1.05; p = 0.01). CONCLUSIONS: Vitrectomy is a good surgical option for RRDCD. Older age, mild preoperative PVR, and perioperative intravitreal triamcinolone acetonide injections increase the primary reattachment rates after one operation. Older age was the only independent prognostic factor for the final retinal reattachment in patients with RRDCD.

A comparison of risk factors for age-related macular degeneration and polypoidal choroidal vasculopathy in Chinese patients.

PURPOSE: Neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) are important vision-threatening diseases worldwide. For effective treatment, the risk factors for the diseases merit investigation. This study aimed to compare the risk factors for nAMD vs. PCV in Chinese patients. METHODS: A total of 946 participants were recruited in this case-control study, including 281 patients with nAMD, 306 patients with PCV, and 359 controls. All participants underwent comprehensive ophthalmic examinations. Information on risk factors were collected by questionnaire. Multivariate logistic regression analyses were performed to investigate the difference in risk factors between nAMD and PCV. In a subgroup of subjects, serum lipid data were obtained and analyzed. RESULTS: Risk factors for nAMD included older age (OR 1.03, P = 0.001), male gender (OR 1.55, P = 0.020), asthma (OR 2.50, P = 0.028), smoking (OR 1.92, P = 0.001), and family history (OR 6.82, P = 0.001), while smoking (OR 1.67, P = 0.013) was the only risk factor for PCV. Compared to patients with PCV, patients with nAMD were more likely to be older and suffer from hyperlipidemia, coronary artery disease, rheumatism, and tumor. Interestingly, higher levels of high-density lipoprotein were positively associated with PCV in the subgroup analysis (OR 7.74, P = 0.011). Besides, results were quite different between the combination of patients with nAMD and PCV and patients with nAMD or PCV alone. CONCLUSIONS: The risk factors for nAMD and PCV is varying with the exception of smoking. Our findings suggest that different strategies might be applied in the clinical management and scientific research on nAMD and PCV.

The influence of actin depolymerization induced by Cytochalasin D and mechanical stretch on interleukin-8 expression and JNK phosphorylation levels in human retinal pigment epithelial cells.

BACKGROUND: This study explores the role of actin cytoskeleton depolymerization induced by Cytochalasin D and mechanical stretch on the interleukin-8 (IL-8) expression and c-jun N-terminal kinase (JNK) phosphorylation levels in human retinal pigment epithelial (RPE) cells. METHODS: A Flexcell FX-5000 Tension system was used to apply cyclic stretch to cultured human RPE cells (ARPE-19) at 0.33 Hz with 20% elongation for 0 h, 6 h or 24 h. The cells were stretched alone or pre-treated with Cytochalasin D. The redistribution of the actin cytoskeleton was evaluated using phalloidin immunofluorescence staining. The protein expression levels of IL-8 and JNK in the RPE cells were determined via Western blotting. RESULTS: The cells in the control groups displayed abundant and uniform phalloidin staining. After exposure to mechanical stretch for 24 h, phalloidin staining revealed an unclear and irregular actin cytoskeleton. In all Cytochalasin D-treated cells, the shrinkage and disruption of the cytoskeletal structure was observed regardless of mechanical stress. The stimulation of the RPE cells with cyclic stretch alone did not induce a significant increase in IL-8 expression and JNK phosphorylation levels, which were similar to those of the control groups. After pre-treatment with Cytochalasin D alone, IL-8 expression and JNK phosphorylation levels were not significantly different at 6 h but were significantly increased by approximately 1.2-fold (1.18 ± 0.05; P<0.01) and 3.0-fold (3.01 ± 0.02; P<0.01) at 24 h, respectively. After the pre-incubation of the RPE cells with Cytochalasin D followed by exposure to cyclic stretch, IL-8 expression and JNK phosphorylation levels increased by approximately 1.3-fold (1.31 ± 0.02; P<0.01) and 1.3-fold (1.31 ± 0.02; P<0.01) at 6 h, respectively, and by 1.7-fold (1.69 ± 0.06; P<0.01) and 3.2-fold (3.21 ± 0.12; P<0.01) at 24 h, respectively. CONCLUSIONS: This study demonstrates that disruption of actin polymerization by cytochalasin D and mechanical stretch upregulates interleukin-8 expression and JNK phosphorylation levels in human RPE cells, which indicates that the integrity of the actin cytoskeleton may play important roles in the pro-inflammatory processes in RPE cells.

Inhibition of choroidal neovascularization by lentivirus-mediated PEDF gene transfer in rats.

AIM: To evaluate the effects of lentivirus-mediated pigment epithelium-derived factor (PEDF) gene transfer performed in treatment of rats with established choroidal neovascularization (CNV), and investigates the mechanism by which PEDF inhibits CNV in rats. METHODS: Brown Norway (BN) rats (n=204) were induced by exposure to a laser, and then randomly assigned to 3 groups: no treatment; treatments with intravitreal injection of lentivirus-PEDF-green fluorescent protein (GFP) or lentivirus-control GFP (free fluorescent protein). Following induction and treatment, the CNV tissue was assessed for form, size and vessel leakage by fluorescein fundus angiography (FFA), optical coherence tomography (OCT), histopathology, and examination of choroidal flat mounts. VEGF, Flk-1, and PEDF expression were evaluated by real-time polymerase chain reaction (PCR) and Western blot. RESULTS: A stable laser-induced rat model of CNV was successfully established, and used to demonstrate lentivirus-mediated PEDG gene transfer by intravitreal injection. Expression of green fluorescence labelled PEDF was observed in the retina up to 28d after injection. An intravitreal injection of lentivirus-PEDF-GFP at 7d led to a significant reduction in the size, thickness and area of CNV showed by FFA, OCT and choroidal flat mounts. PEDF was up-regulated while VEGF and Flk-1 were down-regulated in the lentivirus-PEDF-GFP group. The differences in VEGF and Flk-1 expression in the control and lentivirus-PEDF groups at 7, 14, 21 and 28d after laser induction were all statistically significant. CONCLUSION: Lentivirus-mediated PEDF gene transfer is effective for use in treatment of laser-induced CNV, and PEDF exerts its therapeutic effects by inhibiting expression of VEGF and Flk-1.

Neuroprotective effect of curcumin against oxidative damage in BV-2 microglia and high intraocular pressure animal model.

PURPOSE: The involvement of local and systemic oxidative stress in intraocular pressure (IOP) elevation and optic nerve damage has been hypothesized in the pathogenesis of glaucoma. In this study, we aim to evaluate the antioxidant effects of curcumin in BV-2 microglia oxidative damage and assess its neuroprotective effects in a chronic high IOP rat model. METHODS: BV-2 microglia cell line was used in an in vitro study and Wistar rats were used in an in vivo study. Cultured BV-2 microglia cells were pretreated with 10, 1, or 0.1 µM curcumin for 1 h, and sustained oxidative stress was induced by subjecting BV-2 microglia to 200 µM hydrogen peroxide (H2O2) for 24 h. MTT assay was used to determine cell viability. Changes of intracellular reactive oxygen species (ROS) and apoptosis were analyzed by flow cytometry. Three episcleral veins were cauterized to induce high IOP in Wistar rats and measured by Tonopen. After 6 weeks of treatment with curcumin (10 mg/kg/day) by intragastric administration, surviving of retinal ganglion cells was quantified. Activation of caspase 3, cytochrome c, BAX, and BCL2 was quantified by Western blotting both in BV-2 microglia and in animal model. Data were analyzed with the GraphPad Prism 5.0 software, and P<0.05 was considered to be statistically significant. RESULTS: The in vitro study showed that when BV-2 microglia was pretreated with curcumin, the cell viability increased and the intracellular ROS and apoptosis significantly decreased. In the in vivo study, chronic mild IOP elevation was induced for 4 weeks. In the curcumin-treated group, curcumin protected rat BV-2 microglia from death significantly. In both H2O2-treated BV-2 microglia and glaucoma models, caspase 3, cytochrome c, and BAX were downregulated and BCL2 was upregulated in the curcumin-treated group. CONCLUSIONS: Curcumin affords neuroprotective effects by inhibiting oxidative damage and could be a new or adjunctive treatment for glaucoma.

Pharmacokinetic comparison of ketorolac after intracameral, intravitreal, and suprachoroidal administration in rabbits.

PURPOSE: To investigate the concentrations and pharmacokinetics of ketorolac in the rabbits by three different routes of administrations: a single intracameral, intravitreal, and suprachoroidal injection. METHODS: Fifty-four New Zealand white rabbits received ketorolac (250 µg/0.05 mL) in one eye by a single intracameral injection (group A, n = 18), single intravitreal injection (group B, n = 18), and single suprachoroidal injection (group C, n = 18). Drug concentrations in the vitreous, retina-choroid (RC), and plasma were determined by the methods of high-performance liquid chromatography at 0.5, 1, 2, 4, 8, and 24 hours after injection. The concentrations in the opposite eyes were also investigated. RESULTS: The mean maximum concentrations (Cmax) of ketorolac in the vitreous and RC were 0.378 ± 0.19 µg/mL and 3.15 ± 0.49 µg/g (at 0.5 hours), respectively, in group A; 156.2 ± 20.74 µg/mL (at 0.5 hours) and 208.0 ± 21.67 µg/g (at 1 hours), respectively, in group B; and 0.873 ± 0.34 µg/mL and 56.71 ± 22.64 µg/g (at 0.5 hours), respectively, in group C. In the RC, the area under the curve (AUC0-t) in group B (866.1 ± 52.67 µg/g·h) was higher (P < 0.01) than that in group C (77.10 ± 25.90 µg/g·h). The elimination half-life (t1/2) in group B (3.09 hours) was longer (P < 0.01) than that in group C (1.19 hours). In the control eyes, a drug level below 2 µg/g was detected in the RC in group C. Plasma concentrations were below 0.4 µg/mL in all 3 groups. Ketorolac was detectable in the RC till 24 hours after the intravitreal injection and 8 hours after the suprachoroidal injection. CONCLUSION: Intravitreal injection of ketorolac produced higher intraocular drug concentrations for a longer period compared with the other two routes. Suprachoroidal injection of ketorolac could reach an effective drug level in the RC with short half-lives and low drug levels in the vitreous. The plasma drug concentrations were low by all three routes.