tRNA-derived fragment tRF-30 propels diabetes-induced retinal microvascular complications by regulating STAT3 signaling.

Transfer RNA-derived fragments (tRFs) represent a novel class of non-coding RNA transcripts that possess specific biological functions. However, the involvement of tRFs in retinal microvascular diseases remains poorly understood. In this study, we aimed to reveal whether modulation of tRF-30 expression could attenuate pathological retinal neovascular diseases. Our findings demonstrate a significant upregulation of tRF-30 expression levels in both in vivo models of diabetic retinopathy (DR) and in vitro endothelial sprouting models. Conversely, inhibition of tRF-30 expression suppressed the formation of abnormal neovascularization in the retina in vivo, while reducing the proliferation and migration activity of retinal vascular endothelial cells in vitro. We also found that tRF-30 modulates retinal neovascularization through the tRF-30/TRIB3/signal transducer and activated transcription 3 signaling pathway. Furthermore, we validated a significant upregulation of tRF-30 expression levels in the vitreous humor of DR patients, with high levels of both validity and specificity in diagnostic testing. Collectively, our findings highlight a pro-angiogenic role for tRF-30 in DR. Intervening in the tRF-30 signaling pathway may represent a promising prevention and treatment strategy for retinal angiogenesis.

Resveratrol protects against diabetic retinal ganglion cell damage by activating the Nrf2 signaling pathway.

Objective: Oxidative stress-induced retinal neurodegenerative changes are among the pathological alterations observed in diabetic retinopathy. Resveratrol (RSV), a polyphenolic compound with diverse pharmacological effects, has shown preventive qualities in several neurodegenerative illnesses, including anti-inflammatory, anti-aging, and antioxidant benefits. However, its therapeutic efficacy in diabetic retinal neurodegeneration has not yet been thoroughly elucidated. Our study aimed to explore the protective mechanisms and therapeutic benefits of RSV on diabetic retinal neurodegeneration alterations. Materials and methods: Using streptozotocin, we created a diabetic mouse model and conducted visual electrophysiological examinations on mice from the normal group, diabetic group, and diabetic group treated with RSV. Retinas were harvested for histological staining. Additionally, primary retinal ganglion cells cultured in high glucose conditions were used to assess malondialdehyde (MDA) levels and superoxide dismutase (SOD) levels upon siRNA-mediated nuclear factor erythroid 2-related factor 2 (Nrf2) interference. Protein levels of Nrf-2, heme oxygenase-1 (HO-1), and transcriptional levels of them were also measured. Results: We demonstrated that RSV significantly improved the retinal morphology and function in the diabetic retinopathy model mice. The treated mice exhibited notable improvements in visual electrophysiology, with a significant reduction in retinal ganglion cell apoptosis. Following RSV treatment, the high glucose-cultured ganglion cells demonstrated a considerable rise in SOD levels and a substantial drop in MOD. Moreover, the protein expression of solute carrier family 7 member 11 (SLC7A11) and Nrf2 significantly increased. RT-PCR and Western blot results indicated a significant attenuation of RSV's therapeutic effects upon Nrf2 inhibition. Conclusion: Our findings suggest that RSV may reduce oxidative stress levels in the retina and inhibit retinal ganglion cell apoptosis via reducing the Nrf2/HO-1 pathway, which lessens the harm that excessive glucose causes to the retina.

Selective microRNA expression of exosomes from retinal pigment epithelial cells by oxidative stress.

The function of exosomal miRNAs (miRs) in retinal degeneration is largely unclear. We were aimed to investigate the functions of exosomes as well as their miRs derived from retinal pigment epithelial (RPE) cells following exposure to oxidative stress (OS). After the OS by lipopolysaccharide and rotenone on RPE cells, interleukin-1 beta (IL-1ß), Interleukin-6 (IL-6), Tumor Necrosis Factor-alpha (TNF-α) were upregulated, along with the decreased mitochondrial membrane potential and upregulated oxidative damage marker 8-OH-dG in RPE cells. RPE-derived exosomes were then isolated, identified, injected into the subretinal space in mice. After subretinal injection, RPE-exosomes after OS not only induced higher ROS level and apoptotic retinal cells, but also elevated IL-1ß, IL-6 alongside TNF-α expressions among retina/RPE/choroidal complex. Next, miRs inside the exosomes were sequenced by the next generation sequencing (NGS) technology. NGS revealed that certain miRs were abundant in exosomes, while others were selectively kept by RPE cells. Further, downregulated miRs, like miR-125b-5p, miR-125a-5p, alongside miR-128-3p, and upregulated miR, such as miR-7-5p were validated byRT-qPCR. Finally, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to find the possible target genes of those selective exosomal miRs. Our results proved that the RPE-derived exosomes after OS selectively express certain miRs, providing novel insights into the pathogenesis of age-related macular degeneration (AMD) in future.

Prediction of SMILE surgical cutting formula based on back propagation neural network.

AIM: To predict cutting formula of small incision lenticule extraction (SMILE) surgery and assist clinicians in identifying candidates by deep learning of back propagation (BP) neural network. METHODS: A prediction program was developed by a BP neural network. There were 13 188 pieces of data selected as training validation. Another 840 eye samples from 425 patients were recruited for reverse verification of training results. Precision of prediction by BP neural network and lenticule thickness error between machine learning and the actual lenticule thickness in the patient data were measured. RESULTS: After training 2313 epochs, the predictive SMILE cutting formula BP neural network models performed best. The values of mean squared error and gradient are 0.248 and 4.23, respectively. The scatterplot with linear regression analysis showed that the regression coefficient in all samples is 0.99994. The final error accuracy of the BP neural network is -0.003791±0.4221102 µm. CONCLUSION: With the help of the BP neural network, the program can calculate the lenticule thickness and residual stromal thickness of SMILE surgery accurately. Combined with corneal parameters and refraction of patients, the program can intelligently and conveniently integrate medical information to identify candidates for SMILE surgery.

Evaluation of the Changes in Vessel Density and Retinal Thickness in Patients Who Underwent Unilateral Congenital Cataract Extraction by OCTA.

PURPOSE: To evaluate the changes in vessel density in patients with unilateral congenital cataract after cataract extraction. MATERIALS AND METHODS: Children with unilateral congenital cataract were enrolled in our study. All of the patients underwent congenital cataract extraction and intraocular lens (IOL) implantation successfully. Optical coherence tomography angiography (OCTA) was performed to image the retinal vasculature in the macular and optic disc areas before and after surgery. The differences in vessel density and retinal thickness between groups were compared. RESULTS: We found that the best corrected visual acuity (BCVA) was significantly improved one month after surgery compared with that before surgery (t=5.179, p<0.001). The axial length was also changed one month after surgery (t=5.350, p<0.001). The vessel density in the macular and optic disc areas of the affected eyes was significantly lower than that in the normal eyes, while the vessel density at the posterior pole was significantly improved one month after cataract extraction. CONCLUSION: The decrease in vessel density in the macular and optic disc areas might be a consequence of the congenital cataract. Cataract extraction can relieve the form deprivation of the affected eye and increase the vessel density at the posterior pole of the affected eye significantly.

Evaluation of Vision-Related Quality of Life after Autologous Internal Limiting-Membrane Transplantation for Refractory Macular Holes.

PURPOSE: To evaluate the vision-related quality of life of vitrectomy combined with autologous internal limiting membrane (ILM) transplantation for refractory macular holes (MHs). METHODS: There were 40 eyes with refractory MHs included, and all eyes received 23 G vitrectomy and ILM peeling with autologous ILM transplantation. Preoperative and postoperative basic conditions were recorded. The Chinese version of the vision-related quality-of-life scale was used to evaluate patients after operation. Quality of life, postoperative visual acuity, and size of MHs before operation were assessed with Spearman rank correlations. RESULTS: All patients were followed up for 3 months after surgery. Mean postoperative best-corrected visual acuity had significantly improved after surgery. Vision-related quality of life of patients after surgery was closely related to the MH index, but negatively correlated with best-corrected visual acuity before and after surgery. CONCLUSION: The anatomical structure of refractory MHs with ILM peeling combined with autologous ILM transplantation was largely reduced, and the visual acuity of patients improved significantly.

Gremlin-1: An endogenous BMP antagonist induces epithelial-mesenchymal transition and interferes with redifferentiation in fetal RPE cells with repeated wounds.

Purpose: To investigate the role of Gremlin-1, which is an endogenous antagonist of the bone morphogenetic protein (BMP) signaling pathway, in inducing epithelium-mesenchymal transition (EMT) in fetal RPE cells after repeated wounds. Methods: Subconfluent repetitive passages in fetal RPE cells were regarded as a model of repeated wounds. A phase contrast microscope was used to observe the morphology and pigment formation in cells. The expression of GREM1 (Gene ID: 26585; OMIM 603054) and EMT- or RPE-related genes in cells was evaluated with quantitative PCR (qPCR). Recombinant human protein Gremlin-1 (0.1 µg/ml) was added every day to investigate the molecular effects of Gremlin-1 on fetal RPE cells. The cell migration rate was investigated using a cell wound scratch assay, and western blotting was used to analyze the representative proteins (P-cadherin, ZO-1, vimentin, Smad4, and phosphorylated-Smads). In addition, transfection of siRNA was used to explore the rescue effects on EMT cells through the downregulation of GREM1. Finally, LDN193189, which is a type of pan-inhibitor of BMP receptors, was used to verify whether complete blocking of the BMP pathway interferes with the redifferentiation in low-passage fetal cells, even if the cells were treated with transforming growth factor beta 1 (TGF-ß) inhibitors. Results: In fetal RPE cells, the expression of GREM1 were gradually upregulated with repetitive passages, and at the same time, the function-specific genes in fetal RPE cells (TJP1, PMEL, BEST1, RPE65, and MERTK) were downregulated while the EMT-specific genes were upregulated. In addition, GREM1 had a similar expression pattern as SNAI1, which is a key transcription factor to trigger EMT. Recombinant human Gremlin-1 promoted EMT with the upregulation of SNAI1 and elevated the cell migration rate in a cell scratch assay, as well as decreased the expression of two key transcription factors of RPE embryonic development (MITF and OTX2) and the RPE marker, RPE65. Furthermore, the EMT marker, vimentin, and the TGF-ß pathway downstream transcription factor phosphorylated-Smad2 (p-Smad2) increased, but the epithelial marker, ZO-1, was reduced. Additionally, Smad4, which plays a role as a Snail1 cooperator by binding Smad3, was also increased. In contrast, GREM1 silencing increased the expression of MITF and OTX2, which means there was better redifferentiation in subconfluent fetal RPE cells, but it had little influence on p-Smad2 compared to the negative control group. Finally, by adding LDN193189, the BMP signaling pathway was blocked, and this block led to poor redifferentiation in low-passage cells, although the cells were treated with TGF-ß inhibitors. In addition, as positive feedback to block the BMP pathway, GREM1 was subsequently upregulated. Conclusions: In fetal RPE cells, Gremlin-1 induces EMT and inhibits redifferentiation by promoting the TGF-ß pathway and inhibiting the BMP pathway. GREM1 silencing alleviates EMT and increases the redifferentiation of cells by relieving the blockade of the BMP pathway. However, GREM1 silencing has no effects on the TGF-ß pathway. Thus, Gremlin-1 may serve as a novel target to treat proliferative vitreoretinopathy (PVR) and inhibit subretinal fibrosis, which is a risk factor for influencing the therapeutic effects of anti-vascular endothelial growth factor (anti-VEGF) on neovascular age-related macular degeneration (nAMD).

Phacoemulsification combined with transpupillary removal of silicone oil and intracapsular intraocular lens implantation.

AIM: To estimate the effectiveness of phacoemulsification and foldable intraocular lens (IOL) implantation combined with transpupillary silicone oil removal. METHODS: There were 168 eyes of 168 candidate patients with cataract and silicone oil-filled eyes recruited in our study. All of the patients received the intraocular silicone oil removal surgery by transpupillary drainage and cataract extraction by phacoemulsification. Then the IOL implantation were also performed through corneal incision. RESULTS: The surgery was successfully completed in all eyes. Best corrected visual acuity (BCVA) and postoperative complications were recorded in three months after surgery. There were 143 eyes with BCVA improved, otherwise 25 eyes remained stable at the last follow-up visit. The mean BCVA statistically improved from 20/400±0.02 to 20/100±0.15 (P<0.001) and mean postoperative IOP was 13.85±2.18 mm Hg (P=0.415). No intra-operative complications were reported. CONCLUSION: Phacoemulsification combined with transpupillary removal of silicone oil is a safe and simple effective method. In general, it enables quick recovery of visual acuity with less complication rate.

Protective effect of miR-200b/c by inhibiting vasohibin-2 in human retinal microvascular endothelial cells.

AIMS: Proliferative diabetic retinopathy (PDR), characterized by angiogenesis, can cause serve vision loss and even blindness. Recent studies have suggested a pivotal role of vasohibin-2 (VASH2) in the promotion of angiogenesis in tumor tissues. Here we further investigated the role of VASH2 in the proliferation and migration of retinal endothelial cells. MAIN METHODS: The expression of VASH2 in vascular endothelial cells of epiretinal fibrovascular membranes (FVMs) from PDR patients were detected by immunofluorescence. VASH2 gene interfering lentiviral vectors (VASH2-shRNA) and miR-200b/c were constructed for the evaluation of the VASH2 effect on high glucose induced human retinal microvascular endothelial cell line (HRMECs). Cell proliferation, cell cycle and cell migration were carried out subsequently. The relationship between VASH2 and miR-200b/c was determined by luciferase reporter gene assays. KEY FINDINGS: A positive expression of VASH2 was identified in vascular endothelial cells of FVMs from PDR patients. In HRMECs, cells transfected with shRNA or miR-200b/c mimics showed a significantly reduced VASH2 expression compared with negative control group by real time-polymerase chain reaction and western-blot analysis. Inhibition of VASH2 was demonstrated to suppress cell proliferation and migration from Day 2 to Day 4. The luciferase reporter gene assays confirmed the post-transcriptional regulation of VASH2 by miR-200b/c in HRMECs. SIGNIFICANCE: The present study suggests a protective effect of miR-200b/c on high glucose induced HRMECs dysfunction by inhibiting VASH2. It could be a potential therapeutic strategy to inhibit angiogenesis for the treatment of retinal vascular disease.

Vitreomacular adhesion or vitreomacular traction may affect antivascular endothelium growth factor treatment for neovascular age-related macular degeneration.

OBJECTIVE: The aim of this review is to determine whether vitreomacular adhesion (VMA) or vitreomacular traction (VMT) has an influence on the outcomes of antivascular endothelium growth factor (anti-VEGF) treatment neovascular age-related macular degeneration (nAMD). METHODS: A systematic literature search was performed in Pubmed.gov, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang, SinoMed and ClinicalTrials.gov up to 30 June 2016 to identify eligible studies. RESULTS: Nine studies and 2212 participants were finally identified. At month 6, the mean improvement in best-corrected visual acuity (BCVA) and mean decline in central retinal thickness (CRT) of the VMA/VMT(+) group was less than that of the VMA/VMT(-) group (95% CI -3.05 to -0.96 letters, p=0.0002; 15.53 to 32.98 µm, p<0.00001; respectively); at month 12, there was a small or only marginally significant difference (-0.01 to 2.00 letters, p=0.05; 0.17 to 23.7 µm, p=0.05; respectively) between the groups. During the 12 months, however, the VMA/VMT(+) group required more injections ((0.25 to 0.95), p=0.0008). CONCLUSIONS: In using anti-VEGF drugs to treat nAMD, clinicians should take into account the fact that concurrent VMA or VMT might antagonise the efficacy of anti-VEGF drugs during the early stage of treatment.

Face-down or no face-down posturing following macular hole surgery: a meta-analysis.

PURPOSE: To evaluate the impact of postoperative posturing with or without face-down on the anatomical and functional outcomes of macular hole surgery. METHODS: A literature-based meta-analysis was conducted to identify studies relevant to posturing following macular hole surgery (MHS). PubMed and Web of Science databases were used to retrieve articles up to 1 June 2015. The primary measures included MH closure and ideal vision acuity improvement. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated in Review Manager. RESULTS: Four randomized control trials (RCTs) comprising 251 cases were included in the final meta-analysis. No face-down posturing (FDP) after MHS revealed lower anatomic success rate compared to face-down posturing (OR = 0.33, 95% CI [0.13, 0.81], p = 0.02). For holes smaller than 400 µm in size, the subgroup meta-analysis indicated no significant effect of FDP on successful hole closure (OR = 0.29, 95% CI [0.01, 7.34], p = 0.45). However, when holes were larger than 400 µm, it seemed less effective on MH closure following surgery in no FDP group (OR = 0.23, 95% CI [0.07, 0.71]), and this was statistically significant (p = 0.01). CONCLUSIONS: Our work found that no FDP was not inferior to its face-down counterpart for the success of MHS when macular holes were smaller than 400 µm in size. For macular holes larger than 400 µm, statistical analysis proved that FDP might be necessary. More well-conducted randomized control trials are needed to verify our findings.

[Experimental Investigation on the Electron Temperature of Laser-Induced Mg Plasmas].

A series of plasma characteristic spectral lines of Mg alloy were obtained under nanosecond laser shock produced by a pulsed Nd : YAG laser (1 064 nm, maximum energy 500 mJ), which was taken under standard atmospheric pressure and at room temperature. Results indicated that the evolutionary rates of spectral lines were different, and the laser energy was enough to ionization Mg alloy under this experimental condition by the spectral lines of MgⅠ, MgⅡ. The electron temperature of Mg plasma were calculated by the measured relative Emission-line intensity(MgⅠ383.2 nm, MgⅠ470.3 nm, MgⅠ518.4 nm). The experimental results showed that the secondary excitation Mg atoms could be got under this experimental condition. The electron temperature of Mg plasma decreased with the laser energy reduced while the laser energy was in the range of 200～500 mJ. When the laser energy was in the range of 350～500 mJ, the electron temperature changed rapidly. When the laser energy was in the range of 200～350 mJ, the electron temperature changed slowly and tended towards stability. It is found that when the laser energy was 300 mJ, the plasma temperature raised suddenly, which could not accord with the trend because of plasma shielding. When the laser energy was 300 mJ, the relative intensity of spectral lines was reduced which was lower than that of 350 and 250 mJ. And it is against the variation trend of the relative intensity of spectral lines increases with the increase of laser energy, which prove plasma shielding phenomenon had occurred and plasma with high power laser separate the coupling between laser and material. The plasma temperature was increased significantly, which is not consistent with the trend .When the plasma shielding phenomenon happened, laser energy was absorbed by the plasma, resulting in the rise of plasma temperature.

Association between variants A69S in ARMS2 gene and response to treatment of exudative AMD: a meta-analysis.

A study was undertaken to investigate the association between A69S in age-related maculopathy susceptibility 2 (ARMS2) and the response to anti-angiogenesis treatment in exudative age-related macular degeneration (AMD). A literature-based meta-analysis was performed of studies relevant to A69S and the response to anti-angiogenesis treatment. PubMed, Web of Science, China National Knowledge Infrastructure (CNKI) and Sinomed databases were used to retrieve articles up to July 2014. Pooled ORs and 95% CIs were estimated using fixed and random effects models in Stata V.9.0. Q-statistic testing was used to assess heterogeneity. Twelve articles comprising 2389 cases were included in the final meta-analysis. The analysis of the overall population indicated a statistically significant association between A69S and the response to anti-angiogenesis treatment in exudative AMD (GG vs TT: OR 1.34 (95% CI 1.01 to 1.77), p=0.039; GT vs TT: OR 1.58 (95% CI 1.08 to 2.31), p=0.018; GG+GT vs TT: OR 1.74 (95% CI 1.19 to 2.52), p=0.004). In subgroup analysis, A69S appeared more likely to be a predictor for anti-angiogenic response in the East Asian population (GG vs TT: OR 1.65 (95% CI 1.02 to 2.68), p=0.042; GT vs TT: OR 1.66 (95% CI 1.17 to 2.37), p=0.005; GG+GT vs TT: OR 1.82 (95% CI 1.07 to 3.10), p=0.027; G vs T: OR 1.56 (95% CI 1.01 to 2.41)). However, no statistical significance was found in the Caucasian subgroup analysis. This study shows an association between A69S polymorphism in the ARMS2 gene and the anti-angiogenesis treatment response. A69S could be considered predictive of the anti-angiogenic effects, especially in Asian populations.

Application of 3-dimensional printing technology to construct an eye model for fundus viewing study.

OBJECTIVE: To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. METHODS: We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. RESULTS: In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. CONCLUSIONS: The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research.

Protective effects of astragaloside IV on db/db mice with diabetic retinopathy.

OBJECTIVES: Diabetic retinopathy (DR) is a common diabetic eye disease which is well-known as the result of microvascular retinal changes. Although the potential biological functions of astragaloside IV (AS IV) have long been described in traditional system of medicine, its protective effect on DR remains unclear. This study aims to investigate the function and mechanism of AS IV on type 2 diabetic db/db mice. METHODS: Db/db mice were treated with AS IV (4.5 mg/kg or 9 mg/kg) or physiological saline by oral gavage for 20 weeks along with db/m mice. In each group, retinal ganglion cell (RGC) function was measured by pattern electroretinogram (ERG) and apoptosis was determined by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Blood and retina aldose reductase (AR) activity were quantified by chemiluminescence analysis. The expressions of phosporylated-ERK1/2, NF-κB were determined by Western blot analysis. Furthermore, the expression of related downstream proteins were quantified by Label-based Mouse Antibody Array. RESULTS: Administration of AS IV significantly improved the amplitude in pattern ERG and reduced the apoptosis of RGCs.in db/db mice. Furthermore, downregulation of AR activity, ERK1/2 phosphorylation, NF-κB and related cytokine were observed in AS IV treatment group. CONCLUSIONS: Our study indicated that AS IV, as an inhibitor of AR, could prevent the activation of ERK1/2 phosporylation and NF-kB and further relieve the RGCs disfunction in db/db mice with DR. It has provided a basis for investigating the clinical efficacy of AR inhibitors in preventing DR.

Multiplex bead array assay of plasma cytokines in type 2 diabetes mellitus with diabetic retinopathy.

PURPOSE: The aim of this study was to assess the roles of plasma cytokines in diabetic retinopathy (DR) and their relationship with the severity of DR. METHODS: This study included 59 diabetic patients and 19 non-diabetic controls. The plasma concentrations of endothelial growth factor (EGF), eotaxin, fibroblast growth factor 2 (FGF-2), Flt-3 ligand (Flt-3L), fractalkine, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), growth-related oncogene (GRO), interferon (IFN)-α2, IFN-γ, interleukin (IL)-1α, IL-1ß, IL-1Ra, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17, IFN-inducible protein-10 (IP-10), monocyte chemoattractant protein (MCP)-1, MCP-3, macrophage-derived cytokine (MDC), macrophage inflammatory protein (MIP)-1α, MIP-1ß, sCD40L, sIL-2Rα, transforming growth factor (TGF)-α, tumor necrosis factor (TNF)- α, TNF-ß, and VEGF were measured with Luminex multiplex bead immunoassay. The levels of these cytokines were investigated according to the DR stage. RESULTS: The plasma level of ten cytokines-MCP-1, IL-6, IL-7, IL-9, IL-13, IL-15, IL-17, sCD40L, sIL-2Rα and TNF-ß-increased significantly in the diabetic group compared to the controls. The Flt-3L, IL-1Ra, IL-3, IL-5, and IL-12 (p40) levels were lower in the diabetic group than in the control group. The TNF-α plasma level was significantly elevated in patients with proliferative diabetic retinopathy (PDR) compared with the levels in patients with non-proliferative diabetic retinopathy (NPDR) and patients with no apparent diabetic retinopathy (NDR). CONCLUSIONS: TNF-α might be involved in the progression of DR, especially in the pathogenesis of PDR. TNF-α is a potential cytokine for the prognosis of DR and might act as a therapeutic target in DR.

Edaravone protect against retinal damage in streptozotocin-induced diabetic mice.

Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, is used for the clinical treatment of retinal injury. In this study, we investigated the protective effects of edaravone against diabetic retinal damage in the mouse. Diabetic retinopathy in the mouse was induced by injection of streptozotocin. Edaravone was given once-daily and was intraperitoneally (i.p.) treated at a dose of 3 mg/kg from streptozotocin injection to 4 weeks after onset of diabetes. Retinal ganglion cells (RGCs) damage was evaluated by recording the pattern electroretinogram (ERG). RGCs damage was also detected by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and the levels of reactive oxygen species (ROS) were determined fluorometrically. The expressions of phosporylated-ERK1/2, BDNF, and caspase-3 were determined by Western blot analysis. Retinal levels of ROS, phosphorylated ERK1/2, and cleaved caspase-3 were significantly increased, whereas the expression of BDNF was significantly decreased in the retinas of diabetic mice, compared to nondiabetic mice. Administration of edaravone significantly attenuated diabetes induced RGCs death, upregulation of ROS, ERK1/2 phosphorylation, and cleaved caspase-3 and downregulation of BDNF. These findings suggest that oxidative stress plays a pivotal role in diabetic retinal damage and that systemic administration of edaravone may slow the progression of retinal neuropathy induced by diabetes.

Pharmacokinetics of HM-3 after intravitreal administration in mice.

PURPOSE: HM-3, an RGD-modified endostatin-derived polypeptide, is a potent angiogenesis inhibitor synthesized in our laboratory. This study investigated the HM-3 pharmacokinetics of intravitreally administered in mice eyes as an anti-angiogenesis drug for age-related macular degeneration. MATERIALS AND METHODS: A total of 288 C57BL/6J mice were evaluated and divided into four groups. Each mouse in different groups received single bilateral intravitreal injection with HM-3. The concentrations of HM-3 in choroid/sclera, retina and serum were determined by indirect competitive enzyme-linked immunosorbent assay. RESULTS: After intravitreal administration of doses of 0, 10, 20 and 40 µg/eye HM-3, the observed maximum concentration (Cmax) was 12.98 ± 1.42, 27.87 ± 3.64 and 55.96 ± 11.94 ng/mg, respectively; and the total area under the curve (AUCtot) was 739.23 ± 190.32, 1171.74 ± 528.75 and 1777.71 ± 511.64 h ng/mg; the elimination half-life (T1/2) in retina was 104.85 ± 36.90, 107.42 ± 35.25 and 101.12 ± 15.82 h; the mean residence time (MRT) was 172.46 ± 63.80, 164.70 ± 52.72 and 181.32 ± 26.01 h, respectively. In choroid/sclera, the Cmax was 5.29 ± 0.34, 6.29 ± 1.87 and 8.14 ± 0.71 ng/mg, respectively; AUCtot was 579.03 ± 56.50, 762.20 ± 201.09 and 720.91 ±243.87 h ng/mg; T1/2 was 54.04 ± 25.99, 59.33 ± 24.46 and 47.10 ± 10.00 h, respectively; MRT was 139.98 ± 23.93, 155.43 ± 17.81 and 136.45 ± 18.17 h, respectively. But in serum, the Cmax was 482.00 ± 38.97, 493.94 ± 97.64 and 1033.10 ± 276.33 ng/ml, respectively; AUCtot was 21128.55 ± 4683.68, 53444.57 ± 16963.99 and 53164.84 ±1535.06 h ng/ml; T1/2 was 48.39 ± 14.89, 47.96 ± 12.97 and 49.98 ± 30.07 h, respectively; MRT was 108.6 ± 47.17, 159.76 ± 18.82 and 125.33 ± 21.41 h, respectively. CONCLUSIONS: The pharmacokinetic profiles of intravitreal administration HM-3 provide the basis for the development of reasonable dosing regimens of clinical choroidal neovascularization (CNV) treatment. However, the vitreous and blood retinal barrier might be barriers to drug distribution and diffusion. In addition, fluid flow for the anterior transport and choroidal blood circulation might play important roles for multiple peaking. Carrying out the research into pharmacokinetics of HM-3 provides the information for laying down drug delivery scheme in mice model of CNV.

Genetic association with response to intravitreal ranibizumab for neovascular age-related macular degeneration in the Han Chinese population.

PURPOSE: To investigate a possible association between gene variants and patient response to treatment with intravitreal ranibizumab for neovascular age-related macular degeneration (AMD). METHODS: Visual acuity score (VAS) was recorded at baseline and a subsequent visit at 6 months. Genotypes of 3 polymorphisms in known AMD susceptibility loci (rs1061170 in complement factor H (CFH), rs11200638 in HTRA1 and rs1413711 in VEGF) were determined. Central retinal thickness and maximum thickness of the lesion were also measured. RESULTS: A total of 168 neovascular AMD patients treated with intravitreal ranibizumab were included in our study. For HTRA1 rs11200638, mean VAS changes were 3.5, 9.4 and 10.6 letters for the AA, AG and GG genotypes, respectively (p = 0.022). In contrast, for CFH rs1061170 and VEGF rs1413711, mean VAS changes were not significant. However, there was no significant difference in the changes in central retinal thickness and maximum lesion thickness among the genotypes of the tested single-nucleotide polymorphisms. CONCLUSIONS: HTRA1 gene polymorphism may influence patient response to treatment with intravitreal ranibizumab for neovascular AMD.

The age-related maculopathy susceptibility 2 polymorphism and polypoidal choroidal vasculopathy in Asian populations: a meta-analysis.

OBJECTIVE: To assess the role of the age-related maculopathy susceptibility 2 (ARMS2) A69S polymorphism as a risk factor for polypoidal choroidal vasculopathy (PCV) in Asian populations. METHODS: We performed a meta-analysis of the association of the A69S variant with PCV in Asian populations using data available from 14 case-control studies involving 6552 subjects. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed- and random-effects models. Sensitivity analysis also was performed. MAIN OUTCOME MEASURES: Understanding the relationship between the A69S variant and PCV is essential to provide new insights into pathophysiology and potential targets for intervention of PCV. RESULTS: The pooled OR in random-effects models for genotype TG+TT versus wild homozygous genotype GG is 2.39 (95% CI, 1.98-2.89), the OR of heterozygous genotype TG versus GG is 1.66 (95% CI, 1.37-2.00), the OR of homozygous genotype TT versus GG is 4.74 (95% CI, 3.94-5.70), and the OR of allele T versus G is 2.14 (95% CI, 1.79-2.56). A sensitivity analysis indicated the robustness of our findings. CONCLUSIONS: Our analysis provides evidence that the A69S variant is associated with an increased risk of PCV in Asian populations. The variant of A69S could be a promising genetic biomarker of PCV. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.