Search

Neovascular age-related macular degeneration (nAMD) is a leading cause of vision loss in older adults. nAMD is treated with biologics targeting vascular endothelial growth factor; however, many patients do not respond to the current therapy. Here, a small molecule drug, griseofulvin (GRF), is used due to its inhibitory effect on ferrochelatase, an enzyme important for choroidal neovascularization (CNV). For local and sustained delivery to the eyes, GRF is encapsulated in microparticles based on poly(lactide-co-glycolide) (PLGA), a biodegradable polymer with a track record in long-acting formulations. The GRF-loaded PLGA microparticles (GRF MPs) are designed for intravitreal application, considering constraints in size, drug loading content, and drug release kinetics. Magnesium hydroxide is co-encapsulated to enable sustained GRF release over >30 days in phosphate-buffered saline with Tween 80. Incubated in cell culture medium over 30 days, the GRF MPs and the released drug show antiangiogenic effects in retinal endothelial cells. A single intravitreal injection of MPs containing 0.18 µg GRF releases the drug over 6 weeks in vivo to inhibit the progression of laser-induced CNV in mice with no abnormality in the fundus and retina. Intravitreally administered GRF MPs prove effective in preventing CNV, providing proof-of-concept toward a novel, cost-effective nAMD therapy., (© 2023 The Authors. Small published by Wiley-VCH GmbH.)

Choroidal neovascularization (CNV) is the primary pathogenic process underlying wet age-related macular degeneration, leading to severe vision loss. Despite current anti-vascular endothelial growth factor (VEGF) therapies, several limitations persist. Crocetin, a major bioactive constituent of saffron, exhibits multiple pharmacological activities, yet its role and mechanism in CNV remain unclear. Here, we investigated the potential effects of crocetin on CNV using in vitro and in vivo models. In human umbilical vein endothelial cells, crocetin demonstrated inhibition of VEGF-induced cell proliferation, migration, and tube formation in vitro, as assessed by CCK-8 and EdU assays, transwell and scratch assays, and tube formation analysis. Additionally, crocetin suppressed choroidal sprouting in ex vivo experiments. In the human retinal pigment epithelium (RPE) cell line ARPE-19, crocetin attenuated cobalt chloride-induced hypoxic cell injury, as evidenced by CCK-8 assay. As evaluated by quantitative PCR and Western blot assay, it also reduced hypoxia-induced expression of VEGF and hypoxia-inducible factor 1α (HIF-1α), while enhancing zonula occludens-1 expression. In a laser-induced CNV mouse model, intravitreal administration of crocetin significantly reduced CNV size and suppressed elevated expressions of VEGF, HIF-1α, TNFα, IL-1β, and IL-6. Moreover, crocetin treatment attenuated the elevation of phospho-S6 in laser-induced CNV and hypoxia-induced RPE cells, suggesting its potential anti-angiogenic effects through antagonizing the mechanistic target of rapamycin complex 1 (mTORC1) signaling. Our findings indicate that crocetin may hold promise as an effective drug for the prevention and treatment of CNV., (Copyright © 2023. Published by Elsevier Ltd.)

It has previously been reported that antioxidant vitamins can help reduce the risk of vision loss associated with progression to advanced age-related macular degeneration (AMD), a leading cause of visual impairment among the elderly. Nonetheless, how oxidative stress contributes to the development of choroidal neovascularization (CNV) in some AMD patients and geographic atrophy (GA) in others is poorly understood. Here, we provide evidence demonstrating that oxidative stress cooperates with hypoxia to synergistically stimulate the accumulation of hypoxia-inducible factor (HIF)-1α in the retinal pigment epithelium (RPE), resulting in increased expression of the HIF-1-dependent angiogenic mediators that promote CNV. HIF-1 inhibition blocked the expression of these angiogenic mediators and prevented CNV development in an animal model of ocular oxidative stress, demonstrating the pathological role of HIF-1 in response to oxidative stress stimulation in neovascular AMD. While human-induced pluripotent stem cell (hiPSC)-derived RPE monolayers exposed to chemical oxidants resulted in disorganization and disruption of their normal architecture, RPE cells proved remarkably resistant to oxidative stress. Conversely, equivalent doses of chemical oxidants resulted in apoptosis of hiPSC-derived retinal photoreceptors. Pharmacologic inhibition of HIF-1 in the mouse retina enhanced-while HIF-1 augmentation reduced-photoreceptor apoptosis in two mouse models for oxidative stress, consistent with a protective role for HIF-1 in photoreceptors in patients with advanced dry AMD. Collectively, these results suggest that in patients with AMD, increased expression of HIF-1α in RPE exposed to oxidative stress promotes the development of CNV, but inadequate HIF-1α expression in photoreceptors contributes to the development of GA., Competing Interests: Competing interests statement: A.S. is the cofounder of, holds equity in, is a member of the Board of Directors, and serves as the Chief Executive Officer of HIF Therapeutics, Inc. This arrangement has been reviewed and approved by the Johns Hopkins University in accordance with its conflict of interest policies.

Purpose: Emerging data indicate that metformin may prevent the development of age-related macular degeneration (AMD). Whereas the underlying mechanisms of metformin's anti-aging properties remain undetermined, one proposed avenue is the gut microbiome. Using the laser-induced choroidal neovascularization (CNV) model, we investigate the effects of oral metformin on CNV, retinal pigment epithelium (RPE)/choroid transcriptome, and gut microbiota., Methods: Specific pathogen free (SPF) male mice were treated via daily oral gavage of metformin 300 mg/kg or vehicle. Male mice were selected to minimize sex-specific differences to laser induction and response to metformin. Laser-induced CNV size and macrophage/microglial infiltration were assessed by isolectin and Iba1 immunostaining. High-throughput RNA-seq of the RPE/choroid was performed using Illumina. Fecal pellets were analyzed for gut microbiota composition/pathways with 16S rRNA sequencing/shotgun metagenomics, as well as microbial-derived metabolites, including small-chain fatty acids and bile acids. Investigation was repeated in metformin-treated germ-free (GF) mice and antibiotic-treated/GF mice receiving fecal microbiota transplantation (FMT) from metformin-treated SPF mice., Results: Metformin treatment reduced CNV size (P < 0.01) and decreased Iba1+ macrophage/microglial infiltration (P < 0.005). One hundred forty-five differentially expressed genes were identified in the metformin-treated group (P < 0.05) with a downregulation in pro-angiogenic genes Tie1, Pgf, and Gata2. Furthermore, metformin altered the gut microbiome in favor of Bifidobacterium and Akkermansia, with a significant increase in fecal levels of butyrate, succinate, and cholic acid. Metformin did not suppress CNV in GF mice but colonization of microbiome-depleted mice with metformin-derived FMT suppressed CNV., Conclusions: These data suggest that oral metformin suppresses CNV, the hallmark lesion of advanced neovascular AMD, via gut microbiome modulation.

Angiogenesis, although required during eye development, has a causative effect in many ocular diseases. Aberrant neovascularization contributes to the progression of neovascular age-related macular degeneration (nAMD), a vision-threaten disease in aging Americans. Since increased amounts of vascular endothelial growth factor (VEGF) drives neovascularization during the pathogenesis of nAMD the standard of care are anti-VEGF therapies attempt to disrupt this vicious cycle. These current anti-VEGF therapies try to maintain vascular homeostasis while abating aberrant neovascularization but regrettably don't prevent fibrosis or scar formation. In addition, some patients demonstrate an incomplete response to anti-VEGF therapy as demonstrated by progressive vision loss. Here, we show choroidal endothelial cells (ChEC) incubated with artesunate demonstrated decreased migration and inflammatory and fibrotic factor expression, which corresponded with decreased sprouting in a choroid/retinal pigment epithelium (RPE) explant sprouting angiogenesis assay. To assess the efficacy of artesunate to curtail neovascularization in vivo, we utilized laser photocoagulation-induced rupture of the Bruch's membrane to induce choroidal neovascularization (CNV). Artesunate significantly inhibited CNV and the accompanying fibrotic scar, perhaps due in part to its ability to inhibit mononuclear phagocyte (MP) recruitment. Thus, artesunate shows promise in inhibiting both CNV and fibrosis., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The neovascular form of age-related macular degeneration (nvAMD) is the leading cause of blindness in the elderly population. Vascular endothelial growth factor (VEGF) plays a crucial role in choroidal neovascularization (CNV), and anti-VEGF therapy is recommended as first-line therapy for nvAMD. However, many patients do not radically benefit from this therapy. Epidemiological data suggest that physical exercise is beneficial for many human diseases, including nvAMD. Yet, its protective mechanism and therapeutic potential remain unknown. Here, using clinical samples and mouse models, we found that exercise reduced CNV and enhanced anti-angiogenic therapy efficacy by inhibiting AIM2 inflammasome activation. Furthermore, transfusion of serum from exercised mice transferred the protective effects to sedentary mice. Proteomic data revealed that exercise promoted the release of adiponectin, an anti-inflammatory adipokine from adipose tissue into the circulation, which reduced ROS-mediated DNA damage and suppressed AIM2 inflammasome activation in myeloid cells of CNV eyes through AMPK-p47phox pathway. Simultaneous targeting AIM2 inflammasome product IL-1β and VEGF produced a synergistic effect for treating choroidal neovascularization. Collectively, this study highlights the therapeutic potential of an exercise-AMD axis and uncovers the AIM2 inflammasome and its product IL-1β as potential targets for treating nvAMD patients and enhancing the efficacy of anti-VEGF monotherapy., Competing Interests: Declaration of competing interest Authors declare no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Choroidal neovascularization (CNV) is a hallmark of wet age-related macular degeneration, which severely impairs central vision. Studies have shown that endothelial-mesenchymal transition (EndMT) is involved in the pathogenesis of CNV. Licochalcone A (lico A), a flavonoid extracted from the root of licorice, shows the inhibition on EndMT, but it remains unclear whether it can suppress the formation of CNV. The aim of this study is to investigate the effects of lico A on laser-induced CNV, and EndMT process in vitro and vivo. We established the model of CNV with a krypton laser in Brown-Norway rats and then intraperitoneally injected lico A. Our experimental results demonstrated that the leakage of CNV was relieved, and the area of CNV was reduced in lico A-treated rats. Cell migration and tube formation in oxidized low-density lipoprotein (Ox-LDL)-stimulated HUVECs were inhibited by lico A and promoted by PI3K activator 740Y-P. The protein expressions of snai1 and α-SMA were increased, and CD31 and VE-cadherin were decreased in the model rats of CNV, but partially reversed after treatment with lico A. The expression of CD31 was decreased and α-SMA was increased in OX-LDL-treated HUVECs, which was further strengthened by 740Y-P, while the expression of CD31 was up-regulated and α-SMA was down-regulated in lico A treated HUVECs. Our data revealed that EndMT process was alleviated by lico A. Meanwhile, PI3K/AKT signaling pathway was activated in model rat of CNV and Ox-LDL-stimulated HUVECs, which can be suppressed with treatment of lico A. Our experimental results confirmed for the first time that lico A has the potential to alleviate CNV by inhibiting the endothelial-mesenchymal transition via PI3K/AKT signaling pathway., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background and Purpose: Pathological angiogenesis is a major cause of irreversible blindness in individuals with neovascular age-related macular degeneration (nAMD). Macrophages and microglia (MΦ) contribute to aberrant ocular angiogenesis. However, the role of glucose metabolism of MΦ in nAMD is still undefined. Here, we have investigated the involvement of glycolysis, driven by the kinase/phosphatase PFKFB3, in the development of choroidal neovascularization (CNV)., Experimental Approach: CNV was induced in mice with laser photocoagulation. Choroid/retinal pigment epithelium (RPE) complexes and MΦ were isolated for analysis by qRT-PCR, western blot, flow cytometry, immunostaining, metabolic measurements and angiogenesis assays., Key Results: MΦ accumulated within the CNV of murine nAMD models and expressed high levels of glycolysis-related enzymes and M1/M2 polarization markers. This phenotype of hyper-glycolytic and activated MΦ was replicated in bone marrow-derived macrophages stimulated by necrotic RPE in vitro. Myeloid cell-specific knockout of PFKFB3, a key glycolytic activator, attenuated pathological neovascularization in laser-induced CNV, which was associated with decreased expression of MΦ polarization markers and pro-angiogenic factors, along with decreased sprouting of vessels in choroid/RPE complexes. Mechanistically, necrotic RPE increased PFKFB3-driven glycolysis in macrophages, leading to activation of HIF-1α/HIF-2α and NF-κB, and subsequent induction of M1/M2 markers and pro-angiogenic cytokines, finally promoting macrophage reprogramming towards an angiogenic phenotype to facilitate development of CNV. The PFKFB3 inhibitor AZ67 also inhibited activation of HIF-1α/HIF-2α and NF-κB signalling and almost completely prevented laser-induced CNV in mice., Conclusions and Implications: Modulation of PFKFB3-mediated macrophage glycolysis and activation is a promising strategy for the treatment of nAMD., (© 2022 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Purpose: This study aimed to explore whether RO4929097 (RO), a specific γ-secretase inhibitor, could inhibit the subretinal fibrosis in laser-induced mouse model and the relevant molecular mechanisms., Methods: Male C57BL/6J mice were used to produce choroidal neovascularization (CNV) and subretinal fibrosis by laser photocoagulation, and RO was administered intravitreally 1 day after laser induction. The sizes of CNV and subretinal fibrosis were measured and quantified in both 2D and 3D constructions. The ARPE-19 cell line and primary human RPE (phRPE) cells were treated with TGFβ1, in combination with or without RO, to examine Notch related molecules, epithelial mesenchymal transition (EMT), cell viability, migration, and contractile function, as well as the crosstalk between Notch and other EMT relevant signaling pathways., Results: Intravitreal injection of RO reduced the sizes of both CNV and subretinal fibrosis in laser-induced young and old mice at day 7 and day 14 after laser induction. Moreover, EMT and Notch activation in RPE-choroid complexes from laser-induced mice were significantly attenuated by RO. In vitro, TGFβ1 activated Notch signaling and induced EMT in ARPE-19 cells, accompanied by enhanced EMT-related function, which were inhibited by RO. The inhibition of RO on EMT was further confirmed in TGFβ1-treated phRPE cells. Blockage of Notch signaling by RO could inhibit ERK1/2 signaling; whereas ERK1/2 inhibition had no effect on Notch. The action of RO was independent of Smad2/3 or p38, and co-inhibition of Notch and Smad2/3 showed synergistic effect on EMT inhibition., Conclusions: RO exerts its antifibrotic effect by directly inhibiting Notch signaling and indirectly suppressing ERK1/2 signaling. Targeting Notch signaling might provide a therapeutic strategy in prevention and treatment of subretinal fibrosis in neovascular age-related macular degeneration (nAMD).

Purpose: Choroidal neovascularization (CNV) is the major cause of irreversible vision loss associated with age-related macular disease (AMD). The currently clinical chemical therapeutic strategies are of high cost and facing supply chain shortage. In our study, we aim to investigate EV11, a novel derivative from Sorafenib, as a new approach to inhibit the formation of CNV., Methods: Cell viability assay, wound healing assay, transwell assay and tube formation assay were applied to explore the effects of EV11 on human vascular endothelial cells (HUVECs). Western blotting analysis was performed to investigate the pathways when EV11 acts on HUVECs. Laser-induced CNV in mice and intravitreal injection of EV11 were applied to find out the efficacy of the drug in vivo. Histological examination and electroretinogram (ERG) evaluated the retinal morphology and visual function after drug application., Results: EV11 influenced the HUVECs cell viability as the concentration increasing after 24 hour incubation. It influenced HUVECs through suppressing AKT and ERK1/2 pathway. EV11 reduced CNV area with the optimal concentration of 200uM in mice eyes and compared with Bevacizumab, it had the same effect. The retinal thickness around the optic in each group was not influenced. The amplitudes of the a- and b-waves on scotopic and photopic ERG were not reduced after intravitreal injection., Conclusion: The present study indicated that EV11 affected the proliferation, migration and tube formation of HUVECs, inhibited the area of neovascular of laser induced choroidal neovascularization in mice eyes with no toxicity. EV11 could block the AKT/ERK1/2 signaling pathway in effects of HUVECs. This study unveiled a novel perspective drug EV11 to be a potential candidate for neovascularization., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Choroidal neovascularization (CNV) in age-related macular degeneration (AMD) leads to blindness. It has been widely reported that increased intake of ω-3 long-chain polyunsaturated fatty acids (LCPUFA) diets reduce CNV. Of the three major pathways metabolizing ω-3 (and ω-6 LCPUFA), the cyclooxygenase and lipoxygenase pathways generally produce pro-angiogenic metabolites from ω-6 LCPUFA and anti-angiogenic ones from ω-3 LCPUFA. Howevehr, cytochrome P450 oxidase (CPY) 2C produces pro-angiogenic metabolites from both ω-6 and ω-3 LCPUFA. The effects of CYP2J2 products on ocular neovascularization are still unknown. Understanding how each metabolic pathway affects the protective effect of ω-3 LCPUFA on retinal neovascularization may lead to therapeutic interventions., Objectives: To investigate the effects of LCPUFA metabolites through CYP2J2 pathway and CYP2J2 regulation on CNV both in vivo and ex vivo., Methods: The impact of CYP2J2 overexpression and inhibition on neovascularization in the laser-induced CNV mouse model was assessed. The plasma levels of CYP2J2 metabolites were measured by liquid chromatography and tandem mass spectroscopy. The choroidal explant sprouting assay was used to investigate the effects of CYP2J2 inhibition and specific LCPUFA CYP2J2 metabolites on angiogenesis ex vivo., Results: CNV was exacerbated in Tie2-Cre CYP2J2-overexpressing mice and was associated with increased levels of plasma docosahexaenoic acids. Inhibiting CYP2J2 activity with flunarizine decreased CNV in both ω-6 and ω-3 LCPUFA-fed wild-type mice. In Tie2-Cre CYP2J2-overexpressing mice, flunarizine suppressed CNV by 33 % and 36 % in ω-6, ω-3 LCPUFA diets, respectively, and reduced plasma levels of CYP2J2 metabolites. The pro-angiogenic role of CYP2J2 was corroborated in the choroidal explant sprouting assay. Flunarizine attenuated ex vivo choroidal sprouting, and 19,20-EDP, a ω-3 LCPUFA CYP2J2 metabolite, increased sprouting. The combined inhibition of CYP2J2 with flunarizine and CYP2C8 with montelukast further enhanced CNV suppression via tumor necrosis factor-α suppression., Conclusions: CYP2J2 inhibition augmented the inhibitory effect of ω-3 LCPUFA on CNV. Flunarizine suppressed pathological choroidal angiogenesis, and co-treatment with montelukast inhibiting CYP2C8 further enhanced the effect. CYP2 inhibition might be a viable approach to suppress CNV in AMD., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Choroidal neovascularization (CNV) is the feature of neovascular age-related macular degeneration (AMD). It has been demonstrated that inflammation plays a key role in the development of CNV. Here we aim to investigate how TLR9 agonist (CpG-ODN), one of the key regulators of inflammatory responses, suppresses CNV in vivo., Materials and Methods: The cell viability was assessed by MTT and EdU test after CpG-ODN treatment. Endothelial cells gap assay, tube formation assay and transwell assay were practiced to observe how CpG-ODN affected the endothelial cells functions. The choroidal explants and laser-induced CNV model were built to investigate how CpG-ODN suppressed angiogenesis. The ERK and c-Jun expression were evaluated to assess if CpG-ODN affected cell proliferation. Flow cytometry and qPCR was practiced to observe how CpG-ODN regulated cell proliferation., Results: Our data showed that CpG-ODN not only reduced CNV area in vivo, but also decreased the RPE damage. CpG-ODN inhibited endothelial cells from migration and forming tubes, while the effect was not toxic. EdU test and MTT test suggested that CpG-ODN inhibited endothelial cells proliferation. CpG-ODN significantly increased protein expression of phosphorylated c-Jun but reduced phosphorylated ERK in HUVECs, which was confirmed in ERK transfected 293T cells. JNK inhibitor abolished the suppression of endothelial cells migration and tube formation by CpG-ODN. The findings were also in agreement with the observation in CpG-ODN treated CNV eyes in vivo. The flow cytometry and qPCR data revealed that the suppression of cell motility by CpG-ODN was achieved by arresting endothelial cells cell cycle at G0/G1 phase., Conclusions: Our study demonstrated that CpG-ODN suppressed endothelial cell motility by restricting the cell cycle progression at G0/G1 phase, the effect of which was achieved by interacting with ERK/c-Jun pathways., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background and Purpose: Retinal photodamage is a high-risk factor for age-related macular degeneration (AMD), the leading cause of irreversible blindness worldwide. However, both the pathogenesis and effective therapies for retinal photodamage are still unclear and debated., Experimental Approach: The anti-inflammatory effects of thrombospondin-1 on blue light-induced inflammation in ARPE-19 cells and in retinal inflammation were evaluated. Furthermore, the anti-angiogenic effects of thrombospondin-1 on human microvascular endothelial cells (hMEC-1 cells) and a laser-induced choroidal neovascularisation (CNV) mouse model were evaluated. in vitro experiments, including western blotting, immunocytochemistry, migration assays and tube formation assays, as well as in vivo experiments, including immunofluorescence, visual electrophysiology, spectral-domain optical coherence tomography, and fluorescein angiography, were employed to evaluate the anti-inflammatory and anti-angiogenic effects of thrombospondin-1., Key Results: Specific effects of blue light-induced retinal inflammation and pathological angiogenesis were reflected by up-regulation of pro-inflammatory factors and activation of angiogenic responses, predominantly regulated by the NF-κB and VEGFR2 pathways respectively. During the blue light-induced pathological progress, THBS-1 derived from retinal pigment epithelium down-regulated proteomics and biological assays. Thrombospondin-1 treatment also suppressed inflammatory infiltration and neovascular leakage. The protective effect of Thrombospondin-1 was additionally demonstrated by a substantial rescue of visual function. Mechanistically, thrombospondin-1 reversed blue light-induced retinal inflammation and angiogenesis by blocking the activated NF-κB and VEGFR2 pathways, respectively., Conclusion and Implications: Thrombospondin-1, with dual anti-inflammatory and anti-neovascularisation properties, is a promising agent for protection against blue light-induced retinal damage and retinal degenerative disorders which are pathologically associated with inflammatory and angiogenic progress., Linked Articles: This article is part of a themed issue on Inflammation, Repair and Ageing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.9/issuetoc., (© 2020 The British Pharmacological Society.)

With the dramatic rise in the aging population, researching age-related macular degeneration (AMD), especially the severe form neovascular AMD (nAMD), has become more important than ever. In this study, we found that collagen type X was increased in retina-choroid tissue of mice with laser-induced choroidal neovascularization (CNV) based on immunohistofluorescence. RNA sequencing and bioinformatic analyses were performed to compare the retina-choroid tissue complex of the CNV mouse model to normal controls. Collagen type X alpha 1 chain (Col10a1) was among the most significantly upregulated genes, and the results were validated with an animal model at the mRNA and protein levels by quantitative real-time polymerase chain reaction (qPCR) and western blotting, respectively. COL10A1 was also upregulated in human retinal microvascular endothelial cells (HRMECs), human umbilical vein endothelial cells (HUVECs), RPE19 cells and RF/6A cells under hypoxic conditions. Next, in vitro and in vivo experiments were performed to study the effect of COL10A1 on neovascularization. siRNA knockdown of COL10A1 suppressed the proliferation and tube formation ability of HRMECs under hypoxic conditions. Snail family transcriptional repressor 1 (SNAIL1) and angiopoietin-2 (ANGPT2) were downregulated in COL10A1 knockdown HRMECs under hypoxic conditions and thus were potential downstream genes. Significant decreases in CNV leakage and CNV lesion area, as assessed by fundus fluorescein angiography (FFA) and immunofluorescence of choroidal flat mounts, respectively, were observed in a mouse model intravitreally injected with anti-collagen X monoclonal antibody (mAb) compared to the controls. In conclusion, COL10A1 promotes CNV formation and may represent a new candidate target for the treatment and diagnosis of nAMD and other neovascular diseases., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Eye trauma is an unfortunate and often preventable cause of vision loss. Confetti cannons are common causes of injury. Awareness of ocular hazards of confetti cannons remains low because of limited reports describing ophthalmic injuries following their use., Objectives: To describe outcomes of ocular trauma caused by confetti cannons and to increase recognition of their ocular risks., Methods: A retrospective analysis was conducted of eye injuries caused by confetti cannons presenting to a single medical center between 2016 and 2020. Data collected included age, gender, eye injured, ocular damage, visual outcome, and details of surgeries performed., Results: Overall, six consecutive patients (2 males, mean age 19.5 ± 9.74 years) were identified and studied. In all patients only one eye was injured (3 right eyes) during a private celebration, most commonly (n=5) to a bystander while in the vicinity of a cannon operated by someone else. Most common eye injuries included corneal erosion (n=4), traumatic hyphema (n=4), and retinal edema (n=3). Mean initial logMAR visual acuity in the injured eye was 0.73 ± 0.18, improving to 0.25 ± 0.16 at the final visit (P = 0.125). Two patients underwent eye surgery due to their trauma: one to repair globe penetration and another to undergo intravitreal injection of tissue plasminogen activator and C3F8 for submacular hemorrhage, followed 8 months later by intravitreal bevacizumab injection for choroidal neovascularization., Conclusions: Confetti cannons pose hazards that can cause severe ocular trauma resulting in permanent vision loss. Increasing awareness of device hazards is necessary to prevent eye injuries.

Age-related macular degeneration (AMD) is an eye disease that is characterized by damage to the central part of the retina, the macula, and that affects millions of people worldwide. At an advanced stage, a blind spot grows in the center of vision, severely handicapping patients with this degenerative condition. Despite therapeutic advances thanks to the use of anti-VEGF, many resistance mechanisms have been found to accentuate the visual deficit. In the present study, we explored whether supplementation with Resvega ® , a nutraceutical formulation composed of omega-3 fatty acids and resveratrol, a well-known polyphenol in grapes, was able to counteract laser-induced choroidal neovascularization (CNV) in mice. We highlight that Resvega ® significantly reduced CNV in mice compared with supplementations containing omega-3 or resveratrol alone. Moreover, a proteomic approach confirmed that Resvega ® could counteract the progression of AMD through a pleiotropic effect targeting key regulators of neoangiogenesis in retina cells in vivo. These events were associated with an accumulation of resveratrol metabolites within the retina. Therefore, a supplementation of omega-3/resveratrol could improve the management or slow the progression of AMD in patients with this condition.

Neovascular age-related macular degeneration (nAMD) is a leading cause of blindness. The pathophysiology involves activation of choroidal endothelial cells (CECs) to transmigrate the retinal pigment epithelial (RPE) monolayer and form choroidal neovascularization (CNV) in the neural retina. The multidomain GTPase binding protein, IQGAP1, binds active Rac1 and sustains activation of CECs, thereby enabling migration associated with vision-threatening CNV. IQGAP1 also binds the GTPase, Rap1, which when activated reduces Rac1 activation in CECs and CNV. In this study, we tested the hypothesis that active Rap1 binding to IQGAP1 is necessary and sufficient to reduce Rac1 activation in CECs, and CNV. We found that pharmacologic activation of Rap1 or adenoviral transduction of constitutively active Rap1a reduced VEGF-mediated Rac1 activation, migration, and tube formation in CECs. Following pharmacologic activation of Rap1, VEGF-mediated Rac1 activation was reduced in CECs transfected with an IQGAP1 construct that increased active Rap1-IQGAP1 binding but not in CECs transfected with an IQGAP1 construct lacking the Rap1 binding domain. Specific knockout of IQGAP1 in endothelial cells reduced laser-induced CNV and Rac1 activation in CNV lesions, but pharmacologic activation of Rap1 did not further reduce CNV compared to littermate controls. Taken together, our findings provide evidence that active Rap1 binding to the IQ domain of IQGAP1 is sufficient to interfere with active Rac1-mediated CEC activation and CNV formation., (© 2021 Federation of American Societies for Experimental Biology.)

Pathological myopia, an important blinding eye disease worldwide, has caused a heavy social burden. The patients have become younger in recent years. In general, people have limited knowledge of pathological myopia. They often confuse pathological myopia with high myopia, and do not fully realize that pathological myopia is not only an ametropia disease, but also a fundus disease. Fundus complications of pathological myopia are the main causes of visual impairment, including posterior staphyloma, macular degeneration, and secondary choroidal neovascularization. All of them are related to axial length and can progress throughout the life, while the treatment is limited. At present, myopia prevention has become a national strategy, and pathological myopia is the key and difficult point in myopia prevention. The whole society should pay attention to the prevention and treatment for fundus complications of pathological myopia, take comprehensive measures, and increase scientific researches to protect the eye health of the people. ( Chin J Ophthalmol, 2021, 57: 401-405) .

Purpose: To assess the effect of blue-light filtering (BLF) intraocular lenses (IOLs) on the prevention of neovascular age-related macular degeneration (nAMD) after cataract surgery., Design: Cohort study., Participants: Patients who underwent uneventful cataract surgery between 2007 and 2018 at the Ophthalmology Unit of Kymenlaakso Central Hospital, Kotka, Finland., Methods: Subsequent nAMD rates were compared between patients who received BLF IOLs and those who received non-BLF IOLs. Kaplan-Meier and Cox regression analyses for the overall risk of nAMD developing were assessed. Best-corrected visual acuity (BCVA), foveal thickness, treatment interval, and total number of intravitreal injections were secondary outcomes. A separate analysis was performed on patients with pre-existing nAMD to assess the effect of BLF IOLs on nAMD progression. A single eye of each patient was included., Main Outcome Measure: Neovascular age-related macular degeneration-free survival., Results: Included were 11 397 eyes of 11 397 patients with a mean age of 75.4 ± 8.3 years (62.5% women). The BLF IOL was used in 5425 eyes (47.6%), and the non-BLF IOL was used in 5972 eyes (52.4%). During follow-up (BLF IOL group, 55.2 ± 34.1 months; non-BLF IOL group, 50.5 ± 30.1 months; P < 0.001), 164 cases of new-onset nAMD were recorded (BLF group, n = 88; non-BLF group, n = 76). The nAMD-free survival was similar between the groups (P = 0.465, log-rank test). In a Cox regression analysis controlling for age, gender, and a documented diagnosis of macular degeneration, the use of a BLF IOL was not predictive of nAMD development (hazard ratio [HR], 1.075; 95% confidence interval [CI], 0.79-1.47; P = 0.652). In nAMD patients, secondary clinical outcomes at 1 year were comparable for BCVA (0.57 ± 0.4 logarithm of the minimum angle of resolution vs. 0.45 ± 0.4 logarithm of the minimum angle of resolution; P = 0.136), foveal thickness (285 ± 109 μm vs. 299 ± 103μm; P = 0.527), number of anti-vascular endothelial growth factor injections (6.5 ± 2.5 vs. 6.2 ± 2.7; P = 0.548), and treatment interval (7.5 ± 2.4 weeks vs. 8.1 ± 2.4 weeks; P = 0.271) for BLF and non-BLF IOLs, respectively. Similarly to patients in whom nAMD developed after the surgery, among patients with nAMD before surgery (BLF, n = 71; non-BLF, n = 74), the clinical outcomes again were comparable (all P > 0.05)., Conclusions: In a large cohort of patients who underwent cataract surgery, the use of a BLF IOL resulted in no apparent advantage over a non-BLF IOL in the incidence of nAMD or its progression, nor in clinical variables related to nAMD severity., (Copyright © 2020 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: There is an urgent need for treatments that prevent or delay development to advanced age-related macular degeneration (AMD). Drugs already on the market for other conditions could affect progression to neovascular AMD (nAMD). If identified, these drugs could provide insights for drug development targets. The objective of this study was to use a novel data mining method that can simultaneously evaluate thousands of correlated hypotheses, while adjusting for multiple testing, to screen for associations between drugs and delayed progression to nAMD., Design: We applied a nested case-control study to administrative insurance claims data to identify cases with nAMD and risk-set sampled controls that were 1:4 variable ratio matched on age, gender, and recent healthcare use., Participants: The study population included cases with nAMD and risk set matched controls., Methods: We used a tree-based scanning method to evaluate associations between hierarchical classifications of drugs that patients were exposed to within 6 months, 7 to 24 months, or ever before their index date. The index date was the date of first nAMD diagnosis in cases. Risk-set sampled controls were assigned the same index date as the case to which they were matched. The study was implemented using Medicare data from New Jersey and Pennsylvania, and national data from IBM MarketScan Research Database. We set an a priori threshold for statistical alerting at P ≤ 0.01 and focused on associations with large magnitude (relative risks ≥ 2.0)., Main Outcome Measures: Progression to nAMD., Results: Of approximately 4000 generic drugs and drug classes evaluated, the method detected 19 distinct drug exposures with statistically significant, large relative risks indicating that cases were less frequently exposed than controls. These included (1) drugs with prior evidence for a causal relationship (e.g., megestrol); (2) drugs without prior evidence for a causal relationship, but potentially worth further exploration (e.g., donepezil, epoetin alfa); (3) drugs with alternative biologic explanations for the association (e.g., sevelamer); and (4) drugs that may have resulted in statistical alerts due to their correlation with drugs that alerted for other reasons., Conclusions: This exploratory drug-screening study identified several potential targets for follow-up studies to further evaluate and determine if they may prevent or delay progression to advanced AMD., (Copyright © 2020 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Purpose: Choroidal neovascularization (CNV) is the key pathological change caused by irreversible blindness resulting from neovascular AMD (nAMD). However, the pathological mechanisms underlying CNV remain largely unknown. Here, we aimed to investigate the role of miR-146a-5p in CNV formation., Materials and Methods: At the cellular level, we overexpressed or downregulated miR-146a-5p in an umbilical vein endothelial cell line (EA.hy926) by transfecting cells with either a miR-146a-5p mimic or an inhibitor. CCK8, wound healing, and Matrigel assays were performed to examine the proliferation, migration, and tube formation of endothelial cells (EA.hy926). Target relationship between miR-146a-5p and OTUD7B was verified using a double luciferase reporter experiment. An experimental CNV model was established by treating fundi of male C57BL/6 J mice with 810 nm laser. Fundus fluorescein angiography (FFA) was performed to evaluate the leakage of CNV on day 7 after miR-146a-5p antagomir intravitreal injection. The CNV volume was measured using Choroidal Flatmounts in a confocal study. The expression levels of VEGF, ICAM1, and NF-κB (p50 and p65) were detected both in vitro and in vivo., Results: The expression of miR-146a-5p was increased in LPS-stimulated endothelial cells and in experimental CNV RPE-choroidal complexes in mouse models. LPS-induced proliferation, migration, and tube formation were inhibited by the miR-146a-5p inhibitor. The miR-146a-5p antagomir attenuated CNV formation and fluorescent leakage in the vivo CNV model. In the LPS-stimulated endothelial cells and the CNV mouse model, the NF-κB signaling pathway was activated and the expression of VEGF and ICAM1 increased. Conversely, downregulation of miR-146a-5p inactivated the NF-κB signaling pathway and reduced the expression of VEGF and ICAM1., Conclusions: Our results indicated that downregulation of miR-146a-5p inhibited experimental CNV formation via inactivation of the NF-κB signaling pathway.

Neovascular age-related macular degeneration (nAMD) is a common cause of irreversible vision loss in the elderly. Anti-vascular endothelial growth factor has been effective in treating pathological ocular neovascularization, but it has limitations including the need for repeated intraocular injections for the maintenance of therapeutic effects in most patients and poor or non-response to this agent in some patients. in vitro cellular studies were conducted using retinal pigment epithelial cell lines (ARPE-19 and hTERT-RPE1), human umbilical vein endothelial cells (HUVECs), and human umbilical vein smooth muscle cells (HUVSMCs). in vivo efficacy of ilimaquinone (IQ) was tested in laser-induced choroidal neovascularization mouse and rabbit models. Tissue distribution study was performed in male C57BL6/J mice. IQ, 4,9-friedodrimane-type sesquiterpenoid isolated from the marine sponge, repressed the expression of angiogenic/inflammatory factors and restored the expression of E-cadherin in retinal pigment epithelial cells by inhibiting the Wnt/β-catenin pathway. In addition, it selectively inhibited proliferation and tube formation of HUVECs by activating the p53 pathway. Topical and intraperitoneal administration of IQ significantly reduced choroidal neovascularization in rabbits and mice with laser-induced choroidal neovascularization. Notably, IQ by the oral route of exposure was highly permeable to the eyes and suppressed abnormal vascular leakage by downregulation of β-catenin and stabilization of p53 in vivo. Our findings demonstrate that IQ functions through regulation of p53 and Wnt/β-catenin pathways with conceivable advantages over existing cytokine-targeted anti-angiogenic therapies., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Purpose: To investigate whether triptolide-nanoliposome-APRPG (TP-nanolip-APRPG), a novel sustained-release nano-drug delivery system that targets vascular endothelial cells, could enhance the inhibition of triptolide (TP) on laser-induced choroidal neovascularization (CNV)., Methods: TP was encapsulated with or without APRPG (Ala-Pro-Arg-Pro-Gly) peptide-modified nanoliposomes. CNV was induced by laser photocoagulation in C57BL/6J mice. One microliter of 10 μg free TP monomer, TP-nanolip containing 10 μg TP, TP-nanolip-APRPG containing 10 μg TP, or an identical volume of PBS was intravitreally injected in mice immediately after laser photocoagulation. Seven days after laser photocoagulation, CNV volumes were calculated in each group. Infiltration of M2 macrophages as well as protein levels of vascular endothelial growth factor (VEGF) and inflammatory factors including ICAM-1 and MCP-1 in the RPE-choroid complex were determined. In vitro assays for cell proliferation, migration, and tube formation were also performed., Results: TP-nanolip-APRPG was successfully synthesized and exhibited good TP delivery and enhanced the cellular uptake of TP in vitro. In vitro studies showed that TP-nanolip-APRPG was a better inhibitor of cell proliferation (31.34 ± 3.89 % vs 41.25 ± 4.67 % vs 53.55 ± 5.76 %), migration (62.60 ± 8.88 vs 104.60 ± 13.32 vs 147.00 ± 13.15), and tube formation (681.26 ± 108.15 vs 926.75 ± 54.01 vs 1189.84 ± 157.14) than TP-nanolip or free TP (all P < 0.05). Intravitreal injections of free TP (77588.10±7719.28 μm 3 ), TP-nanolip (64628.23 ± 5857.96 μm 3 ), and TP-nanolip-APRPG (50880.34 ± 6606.56 μm 3 ) inhibited the development of CNV compared with the PBS control group (120338.07 ± 17428.90 μm 3 ) (P < 0.01, n=6). TP-nanolip-APRPG and TP-nanolip significantly down-regulated the protein levels of VEGF (152.76±19.55 vs 182.24±19.98 vs 208.55±21.93 pg/mg total protein) and inflammatory factors including ICAM-1 (61.69±3.49 vs 72.04±3.49 vs 81.92±4.09 ng/mg total protein) and MCP-1 (40.14±3.50 vs 50.75±4.18 vs 60.27±5.23 pg/mg total protein) compared with the free TP monomer group (all P < 0.05, n=8), which paralleled the decreased infiltration of M2 macrophages in the CNV lesions. Moreover, no influence on retinal morphology and function was observed before or after treatment in each group (P > 0.05, n=6)., Conclusions: TP-nanolip-APRPG, a novel sustained-release drug delivery system targeting endothelial cells of CNV lesions, could enhance TP inhibition of the development of CNV without toxicity in the retina, suggesting therapeutic potential for CNV-related diseases in future clinical practice., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Purpose: To assess the therapeutic effects of fursultiamine on choroidal neovascularization (CNV) through its modulation of inflammation and metabolic reprogramming in the retinal pigment epithelium (RPE)., Methods: The anti-angiogenic effects of fursultiamine were assessed by measuring vascular leakage and CNV lesion size in the laser-induced CNV mouse model. Inflammatory responses were evaluated by quantitative polymerase chain reaction, western blot, and ELISA in both CNV eye tissues and in vitro cell cultures using ARPE-19 cells or primary human RPE (hRPE) cells under lipopolysaccharide (LPS) treatment or hypoxia. Mitochondrial respiration was assessed by measuring oxygen consumption in ARPE-19 cells treated with LPS with or without fursultiamine, and lactate production was measured in ARPE-19 cells subjected to hypoxia with or without fursultiamine., Results: In laser-induced CNV, fursultiamine significantly decreased vascular leakage and lesion size, as well as the numbers of both choroidal and retinal inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α. In LPS-treated ARPE-19 cells, fursultiamine decreased proinflammatory cytokine secretion and nuclear factor kappa B phosphorylation. Furthermore, fursultiamine suppressed LPS-induced upregulation of IL-6, IL-8, and monocyte chemoattractant protein-1 in a dose-dependent and time-dependent manner in primary hRPE cells. Interestingly, fursultiamine significantly enhanced mitochondrial respiration in the LPS-treated ARPE-19 cells. Additionally, fursultiamine attenuated hypoxia-induced aberrations, including lactate production and inhibitory phosphorylation of pyruvate dehydrogenase. Furthermore, fursultiamine attenuated hypoxia-induced VEGF secretion and mitochondrial fission in primary hRPE cells that were replicated in ARPE-19 cells., Conclusions: Our findings show that fursultiamine is a viable putative therapeutic for neovascular age-related macular degeneration by modulating the inflammatory response and metabolic reprogramming by enhancing mitochondrial respiration in the RPE.

Purpose: To investigate whether triptolide has inhibitory effects on the development of choroidal neovascularization (CNV), together with its underlying anti-angiogenic mechanisms., Methods: CNV was induced in C57BL/6 J mice using laser photocoagulation. Triptolide at concentrations of 0.035 and 0.07 mg/kg body weight (BW) or the same volume of phosphate-buffered saline (PBS) was intraperitoneally injected into mice 2 days before laser photocoagulation, which was continued daily till the end of the experiment. CNV areas were measured on day 7. The numbers of M1, M2, and F4/80 + macrophages were detected on day 1, 3, and 7 in each group. The levels of vascular endothelial growth factor (VEGF) and inflammatory molecules,including intercellular adhesion molecule (ICAM)-1,tumor necrosis factor (TNF)-α, and interleukin 6 (IL-6) were determined by enzyme-linked immunosorbent assay. Cell proliferation, migration, and tube-formation assays were performed in vitro., Results: Triptolide at doses of 0.035 mg/kg BW (66,562 ± 39,253 μm 2 , n = 5, P＜0.05) and 0.07 mg/kg BW (37,271 ± 25,182 μm 2 , n = 5, P＜0.001) significantly reduced CNV areas by 54.9 and 74.8 %, respectively, compared with PBS control (147,699 ± 112,900 μm 2 , n = 5) in a dose-dependent manner. Protein levels of VEGF, ICAM-1, TNF-α, and IL-6 in the RPE-choroid-sclera complex were significantly downregulated by triptolide treatment on day 3, which was in accordance with the reduced number of infiltrated F4/80 + macrophages and the reduced ratio of M2/F4/80 + macrophages. However, no toxic effects of triptolide on the retina or other systemic organs were observed. In addition, triptolide treatment exerted inhibitory effects on cell proliferation, migration, and tube formation in vitro in a concentration-dependent manner., Conclusions: Triptolide has therapeutic potential in CNV owing to its anti-angiogenic effect., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

This study aims to report the 12 months results of efficacy and safety of laser photocoagulation and anti-vascular endothelial growth factor (VEGF) injections for drusenoid pigment epithelial detachment (dPED). In this prospective study, patients with treatment naïve bilateral intermediate age-related macular degeneration, featuring dPED, with visual acuity ≤ 83 letters were enrolled. The study group received PASCAL laser (532 nm) along the periphery of the dPED, and the fellow eye served as a control group. To prevent complications of choroidal neovascularization, intravitreal anti-VEGF injections to laser treated eye were performed on a 3-month interval up to 1 year. Primary outcomes-drusen area, PED height-and secondary outcomes-best-corrected visual acuity (BCVA), contrast sensitivity, degree of metamorphopsia, NEI-VFQ 25, and fundus autofluorescence-were analyzed. Among 21 patients, a total of 20 patients satisfied the 12 months follow-up. Drusen area and PED height decreased significantly in the laser group, while no significant change appeared in the control group (74.1% vs. - 3.5%, P < 0.001; 76.6% vs. 0.1%, P < 0.001). Mean BCVA improved 4.6 letters in the laser group (vs. 1.1 letters in the control group, P = 0.019). As for safety, one study eye developed retinal pigment epithelial tear, and one control eye developed retinal angiomatous proliferation. Low energy laser photocoagulation and anti-VEGF injection in eyes with dPED showed some improvement in visual acuity. dPED regressed without developing center involving GA in the study eye, but a longer term follow-up is necessary to reveal the efficacy and safety of these treatments. The 2-year results of this study will be followed to reveal long term efficacy and safety of the treatment for dPED.

Purpose: Ciliary neurotrophic factor (CNTF) is a well-characterized neurotrophic factor currently in clinical trials for the treatment of macular telangiectasia type II. Our previous work showed that CNTF-induced STAT3 signaling is a potent inhibitor of pathologic preretinal neovascular tuft formation in the mouse model of oxygen-induced retinopathy. In this study, we investigated the effect of CNTF on outer retinal and choroidal angiogenesis and the mechanisms that underpin the observed decrease in outer retinal neovascularization following CNTF treatment., Methods: In the Vldlr-/- and laser-CNV mouse models, mice received a one-time injection (on postnatal day [P] 12 in the Vldlr-/- model and 1 day after laser in the Choroidal Neovascularization (CNV) model) of recombinant CNTF or CxCl10, and the extent of neovascular lesions was assessed 6 days posttreatment. STAT3 downstream targets affected by CNTF treatment were identified using quantitative PCR analysis. A proteome array was used to compare media conditioned by CNTF-treated and control-treated primary Müller cells to screen for CNTF-induced changes in secreted angiogenic factors., Results: Intravitreal treatment with recombinant CNTF led to significant reduction in neovascularization in the Vldlr-/- and laser-CNV mouse models. Treatment effect in the Vldlr-/- was long-lasting but time sensitive, requiring intravitreal treatment before P19. Mechanistic workup in vitro as well as in vivo confirmed significant activation of the STAT3-signaling pathway in Müller cells in response to CNTF treatment and upregulation of CxCl10. Intravitreal injections of recombinant CxCl10 significantly reduced outer retinal neovascularization in vivo in both the Vldlr-/- and laser-CNV mouse models., Conclusions: CNTF treatment indirectly affects outer retinal and choroidal neovascularization by inducing CxCl10 secretion from retinal Müller cells.

Selective inhibition of vascular endothelial growth factor receptor (VEGFR), particularly VEGFR-2, is an efficient method for the treatment of ocular neovascularization. SU1498 is a specific inhibitor of VEGFR-2. In this study, we investigated the role of SU1498 in ocular neovascularization. Administration of SU1498 did not show any cytotoxicity and tissue toxicity at the tested concentrations. Administration of SU1498 reduced the size and thickness of choroidal neovascularization and decreased the mean length and mean number of corneal neovascular vessels induced by alkali burn. Pretreatment of SU1498 significantly reduced the proliferation, migration, and tube formation ability of HUVECs. SU1498 played the anti-angiogenic role through the regulation of p38-MAPK signaling. Taken together, inhibition of VEGFR-2 by SU1498 provides a novel therapeutic approach for ocular neovascularization., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest in this work., (Copyright © 2020 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

To examine whether free fatty acid receptor 4 (FFAR4) activation can protect against choroidal neovascularization (CNV), which is a common cause of blindness, and to elucidate the mechanism underlying the inhibition, we used the mouse model of laser-induced CNV to mimic angiogenic aspects of age-related macular degeneration (AMD). Laser-induced CNV was compared between groups treated with an FFAR4 agonist or vehicle, and between FFAR4 wild-type (Ffar4 +/+ ) and knock out (Ffar4 -/- ) mice on a C57BL/6J/6N background. The ex vivo choroid-sprouting assay, including primary retinal pigment epithelium (RPE) and choroid, without retina was used to investigate whether FFAR4 affects choroidal angiogenesis. Western blotting for pNF-ĸB/NF-ĸB and qRT-PCR for Il-6, Il-1β, Tnf-α, Vegf, and Nf-ĸb were used to examine the influence of FFAR4 on inflammation, known to influence CNV. RPE isolated from Ffar4 +/+ and Ffar4 -/- mice were used to assess RPE contribution to inflammation. The FFAR4 agonist suppressed laser-induced CNV in C57BL/6J mice, and CNV increased in Ffar4 -/- compared to Ffar4 +/+ mice. We showed that the FFAR4 agonist acted through the FFAR4 receptor. The FFAR4 agonist suppressed mRNA expression of inflammation markers (Il-6, Il-1β) via the NF-ĸB pathway in the retina, choroid, RPE complex. The FFAR4 agonist suppressed neovascularization in the choroid-sprouting ex vivo assay and FFAR4 deficiency exacerbated sprouting. Inflammation markers were increased in primary RPE cells of Ffar4 -/- mice compared with Ffar4 +/+ RPE. In this mouse model, the FFAR4 agonist suppressed CNV, suggesting FFAR4 to be a new molecular target to reduce pathological angiogenesis in CNV.

Age-related macular disease and diabetic retinopathy are chronic degenerative diseases characterised by progressive visual impairment. In Europe, age-related macular disease accounts for over 15% of blindness in adults over 50 years of age, and although the burden of diabetic retinopathy in terms of vision impairment is lower, vision loss associated with diabetic retinopathy is increasing with the rising prevalence of diabetes mellitus and the ageing of the population. Late-stage age-related macular disease can be subdivided into dry (non-neovascular) or wet (neovascular or exudative) forms. The large Age-Related Eye Disease Study 2 showed that supplementation with antioxidant nutrients reduces choroids neovascularisation and reduces the risk of progression of neovascular age-related macular disease. Antioxidant micronutrient supplements have also shown promising results in preventing the pathogenesis of retinopathy in animal models of diabetes. Age-related macular disease and diabetic retinopathy are understood to share some common pathophysiological characteristics, suggesting that micronutrients have an important role in ocular health in both conditions. This article will review the current evidence for the utility of micronutrients in preventing the development and progression of neovascular age-related macular disease and diabetic retinopathy.

Cerium oxide nanoparticles (CeO 2 -NPs; or nanoceria) have been largely studied for biomedical applications due to their peculiar auto-regenerative antioxidant activity. This review focuses on ophthalmic applications of nanoceria. Many in vivo data indicate that nanoceria protect the retina from neurodegeneration. In particular, they have been tested in animal models of age-related macular degeneration and retinitis pigmentosa and their neuroprotective properties have been shown to persist for a long time, without any collateral effects. In vitro cytotoxicity studies have shown that CeO 2 -NPs could be safe for lens cells and could represent a new therapy for cataract treatment, but further studies are needed. To date, different pharmaceutical formulations based on nanoceria have been created looking at future clinical ophthalmic applications, such as water-soluble nanoceria, glycol chitosan-coated ceria nanoparticles (GCCNPs), and alginate-gelatin hydrogel loaded GCCNPs. GCCNPs were also effective in preventing choroidal neovascularization in vivo . Based on the nanosize of nanoceria, corneal permeation could be achieved to allow topical treatment of nanoceria. PEGylation and encapsulation in liposomes represent the main strategies to support corneal permeation, without altering nanoceria chemical-physical properties. Based on their great antioxidant properties, safety, and nanosize, nanoceria represent a new potential therapeutic for the treatment of several eye disorders.

Purpose: To determine the effect of voluntary exercise on choroidal neovascularization (CNV) in mice., Methods: Age-matched wild-type C57BL/6J mice were housed in cages equipped with or without running wheels. After four weeks of voluntary running or sedentariness, mice were subjected to laser injury to induce CNV. After surgical recovery, mice were placed back in cages with or without exercise wheels for seven days. CNV lesion volumes were measured by confocal microscopy. The effect of wheel running only in the seven days after injury was also evaluated. Macrophage abundance and cytokine expression were quantified., Results: In the first study, exercise-trained mice exhibited a 45% reduction in CNV volume compared to sedentary mice. In the replication study, a 32% reduction in CNV volume in exercise-trained mice was observed (P = 0.029). Combining these two studies, voluntary exercise was found to reduce CNV by 41% (P = 0.0005). Exercise-trained male and female mice had similar CNV volumes (P = 0.99). The daily running distance did not correlate with CNV lesion size. Exercise only after the laser injury without a preconditioning period did not reduce CNV size (P = 0.41). CNV lesions of exercise-trained mice also exhibited significantly lower F4/80+ macrophage staining and Vegfa and Ccl2 mRNA expression., Conclusions: These findings provide the first experimental evidence that voluntary exercise improves CNV outcomes. These studies indicate that exercise before laser treatment is required to improve CNV outcomes.

Wet age-related macular degeneration (AMD) and diabetic retinopathy are the leading causes of blindness through increased angiogenesis. Although VEGF-neutralizing proteins provide benefit, inconsistent responses indicate a need for new therapies. We previously identified the Fibulin-7 C-terminal fragment (Fbln7-C) as an angiogenesis inhibitor in vitro. Here we show that Fbln7-C inhibits neovascularization in vivo, in both a model of wet AMD involving choroidal neovascularization (CNV) and diabetic retinopathy involving oxygen-induced ischemic retinopathy. Furthermore, a short peptide sequence from Fbln7-C is responsible for the anti-angiogenic properties of Fbln7-C. Our work suggests Fbln7-C as a therapeutic candidate for wet AMD and ischemic retinopathy., (Published by Elsevier Inc.)

Retinal vascular diseases (RVD) have been identified as a major cause of blindness worldwide. These pathologies, including the wet form of age-related macular degeneration, retinopathy of prematurity, and diabetic retinopathy are currently treated by intravitreal delivery of anti-vascular endothelial growth factor (VEGF) agents. However, repeated intravitreal injections can lead to ocular complications and resistance to these treatments. Thus, there is a need to find new targeted therapies. Nucleolin regulates the endothelial cell (EC) activation and angiogenesis. In previous studies, we designed a pseudopeptide, N6L, that binds the nucleolin and blocks the tumor angiogenesis. In this study, the effect of N6L was investigated in two experimental models of retinopathies including oxygen-induced retinopathy (OIR) and choroidal neovascularization (CNV). We found that in mouse OIR, intraperitoneal injection of N6L is delivered to activated ECs and induced a 50% reduction of pathological neovascularization. The anti-angiogenic effect of N6L has been tested in CNV model in which the systemic injection of N6L induced a 33% reduction of angiogenesis. This effect is comparable to those obtained with VEGF-trap, a standard of care drug for RVD. Interestingly, with preventive and curative treatments, neoangiogenesis is inhibited by 59%. Our results have potential interest in the development of new therapies targeting other molecules than VEGF for RVD., (© 2020 Federation of American Societies for Experimental Biology.)

Neovascular age-related macular degeneration is one of the leading causes of blindness. Microglia and macrophages play a critical role in choroidal neovascularization (CNV) and may, therefore, be potential targets to modulate the disease course. This study evaluated the effect of the colony-stimulating factor-1 receptor inhibitor PLX5622 on experimental laser-induced CNV. A 98% reduction of retinal microglia cells was observed in the retina 1 week after initiation of PLX5622 treatment, preventing accumulation of macrophages within the laser site and leading to a reduction of leukocytes within the choroid after CNV induction. Mice treated with PLX5622 had a significantly faster decrease of the CNV lesion size, as revealed by in vivo imaging and immunohistochemistry from day 3 to day 14 compared with untreated mice. Several inflammatory modulators, such as chemokine (C-C motif) ligand 9, granulocyte-macrophage colony-stimulating factor, soluble tumor necrosis factor receptor-I, IL-1α, and matrix metallopeptidase-2, were elevated in the acute phase of the disease when microglia were ablated with PLX5622, whereas other cytokines (eg, interferon-γ, IL-4, and IL-10) were reduced. Our results suggest that colony-stimulating factor-1 receptor inhibition may be a novel therapeutic target in patients with neovascular age-related macular degeneration., (Copyright © 2020 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Purpose: Targeting β-adrenergic receptor signaling with propranolol has emerged as a potential candidate to counteract choroidal neovascularization (CNV). Little is known of its effect on macrophages, which play a critical role in CNV. We investigated the effect of propranolol on angiogenic response of mononuclear phagocytes (MPs)., Methods: The angiogenic effect of propranolol was evaluated in laser-induced CNV model. Mice received intraperitoneal injections of propranolol (6 mg/kg/d) or vehicle. CNV area and inflammatory cells were determined respectively by using lectin staining and an anti-IBA-1 antibody on RPE/choroid flat mounts. Inflammatory gene expression was evaluated by quantitative (q) PCR analysis. Mechanisms of propranolol was studied in MP cell lines J774 and RAW264.7 and in primary peritoneal macrophages. Expression of pro- and antiangiogenic mediators was studied. In addition, effects of propranolol treatment of MPs was assessed on choroidal explant., Results: CNV was attenuated by propranolol and concomitantly associated with decreased inflammatory mediators IL-6 and TNFα, albeit with accumulation of (β-adrenoceptor harboring) MPs in the CNV area. Conditioned media from MPs preincubated with propranolol exerted antiangiogenic effects. Treatment of J774 confirmed the attenuation of inflammatory response to propranolol and increased cleaved caspase-3 on choroidal explant. We found that propranolol increased pigment epithelium-derived factor (PEDF) expression in MPs. Trapping of PEDF with an antibody abrogated antiangiogenic effects of propranolol. PEDF was also detected in CNV-associated MPs., Conclusions: We hereby show that propranolol confers on MPs antiangiogenic properties by increasing PEDF expression, which complements its effects on vascular tissue resulting in inhibition of choroidal vasoproliferation in inflammatory conditions. The study supports possible use of propranolol as a therapeutic modality for CNV.

Abnormal migration and proliferation of endothelial cells (EC) drive neovascular retinopathies. While anti-VEGF treatment slows progression, pathology is often supported by decrease in intraocular pigment epithelium-derived factor (PEDF), an endogenous inhibitor of angiogenesis. A surface helical 34-mer peptide of PEDF, comprising this activity, is efficacious in animal models of neovascular retina disease but remains impractically large for therapeutic use. We sought smaller fragments within this sequence that mitigate choroidal neovascularization (CNV). Expecting rapid intravitreal (IVT) clearance, we also developed a method to reversibly attach peptides to nano-carriers for extended delivery. Synthetic fragments of 34-mer yielded smaller anti-angiogenic peptides, and N-terminal capping with dicarboxylic acids did not diminish activity. Charge restoration via substitution of an internal aspartate by asparagine improved potency, achieving low nM apoptotic response in VEGF-activated EC. Two optimized peptides (PEDF 335, 8-mer and PEDF 336, 9-mer) were tested in a mouse model of laser-induced CNV. IVT injection of either peptide, 2-5 days before laser treatment, gave significant CNV decrease at day +14 post laser treatment. The 8-mer also decreased CNV, when administered as eye drops. Also examined was a nanoparticle-conjugate (NPC) prodrug of the 9-mer, having positive zeta potential, expected to display longer intraocular residence. This NPC showed extended efficacy, even when injected 14 days before laser treatment. Neither inflammatory cells nor other histopathologic abnormalities were seen in rabbit eyes harvested 14 days following IVT injection of PEDF 336 (>200 μg). No rabbit or mouse eye irritation was observed over 12-17 days of PEDF 335 eye drops (10 mM). Viability was unaffected in 3 retinal and 2 choroidal cell types by PEDF 335 up to 100 μM, PEDF 336 (100 μM) gave slight growth inhibition only in choroidal EC. A small anti-angiogenic PEDF epitope (G-Y-D-L-Y-R-V) was identified, variants (adipic-Sar-Y-N-L-Y-R-V) mitigate CNV, with clinical potential in treating neovascular retinopathy. Their shared active motif, Y - - - R, is found in laminin (Ln) peptide YIGSR, which binds Ln receptor 67LR, a known high-affinity ligand of PEDF 34-mer., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: Choroidal neovascularization (CNV) is the principal pathological factor contributing to blindness in neovascular age-related macular degeneration (nAMD). Infiltration of M2 macrophage is thought to contribute to CNV progress, although the way that regulates its differentiation remains unclear. Here, we investigate the role of CHI3L1 in M2 differentiation and angiogenesis in CNV., Methods: Serums from nAMD patients were tested for CHI3L1 expression. Mice were subjected to laser injury to induce CNV, and lesion expansion were tracked using fundus fluorescence angiography (FFA) and immunofluorescence analysis. Several strategies were taken to verify the contribution of M2 macrophage and CHI3L1: macrophage depletion by clodrosome, local CHI3L1 inhibition using intravitreally injection neutralize antibody (mAY), and depletion of CHI3L1 receptor (IL13-Ra2) by small-interfering RNA (siRNA). Tuber analysis was used to further determine angiogenetic effect of CHI3L1. Anti-VEGFA was used as positive control for mAY., Results: Serum levels of CHI3L1 were highly elevated in nAMD patients. CHI3L1 was expressed by infiltrating M2 macrophages and was elevated as CNV progress in a mice model. System macrophage depletion and local suppression of CHI3L1 alleviated CNV formation while enhancing anti-VEGFA therapeutic effect. Stimulation of macrophage with recombinant CHI3L1 activated MAPK signaling cascade and induced transition to M2, while siRNA knockdown of IL13-Ra2 abolished it. In an in vitro coculture system, supernatants from CHI3L1-stimulated M2 macrophages and promoted tube vascularization., Conclusions: These results unveil novel angiogenic regulation of CHI3L1 and M2 polarized macrophages in CNV development. These mechanistic insights may point to CHI3L1 as a new therapeutic target for treatment for nAMD.

Leading causes of vision loss include neovascular age-related macular degeneration (NVAMD) and macular edema (ME), which both require frequent intravitreal injections for treatment. A safe, poly(lactic-co-glycolic acid) (PLGA)-based biodegradable polymeric microparticle (MP) delivery system was developed that encapsulates and protects a biomimetic peptide from degradation, allows sustained intraocular release through polymer hydrolysis, and demonstrates a prolonged anti-angiogenic effect in vivo in three different NVAMD animal models (a laser-induced choroidal neovascularization mouse model, a rhoVEGF transgenic mouse model, and a Tet/opsin/VEGF transgenic mouse model) following intravitreal administration. The role of copolymer composition and microparticle shape was explored and 85:15 lactide-to-glycolide PLGA formed into ellipsoidal microparticles was found to be effective at inhibiting neovascularization for at least 16 weeks in vivo. Treatments were found to not only inhibit the growth of neovascularization, but also to cause regression of the neovasculature, reduce vascular leakage, and prevent exudative retinal detachment. These particulate devices are promising for the sustained release of biologics in the eye and may be useful for treating retinal diseases. STATEMENT OF SIGNIFICANCE: Devastating retinal diseases cause blindness in millions of people around the world. Current protein-based treatments have insufficient efficacy for many patients and also necessitate frequent intravitreal injections. Here, we demonstrate a new treatment consisting of a peptide encapsulated in biodegradable microparticles. We explore the effects of copolymer composition and physical shape of polymeric microparticles and find that both modulate peptide release. Efficacy of the treatment was validated in three different mouse models and the lead formulation was determined to be effective long-term, for at least 16 weeks in vivo, following a single injection. Treatments inhibited and regressed neovascularization as well as reduced vascular leakage. Anisotropic polymeric microparticles are promising for the sustained release of biologics in the eye., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Aims: Age-related macular degeneration (AMD) is a leading cause of irreversible blindness in elderly people. The pathogenesis of neovascular AMD is known but is closely related to inflammation and choroidal neovascularization (CNV). The aim of this study was to investigate the anti-inflammatory and anti-angiogenic effects of calcium on neovascular AMD., Main Methods: Human retinal pigment epithelial cells (ARPE-19) were used to identify protein markers of inflammation induced by differentiated macrophages. Choroidal neovascularization (CNV) mouse model was established by rupturing the Bruch's membrane using laser photocoagulation in C57BL/6 mice. Mice were divided into the following groups: untreated control and calcium supplemented. The expression levels of toll-like receptor isotype (TLR) 4, nuclear factor kappa B (NF-κB), hypoxia-inducible factor-1α (Hif-1α), and vascular endothelial growth factor (VEGF) were investigated to check whether calcium supplementation results in suppression of inflammation and has an anti-angiogenic effect. CNV was evaluated by immunofluorescence staining on choroidal flat mounts., Key Finding: The inflammation-induced expression of TLR4, NF-κB, and Hif-1α was decreased in ARPE-19 cells after calcium supplementation. Inhibition of the transcriptional activation of ARPE-19 cells by Hif-1α suppression resulted in decreased VEGF expression. In the laser-induced CNV mouse model, calcium supplementation inhibited inflammatory mediators and neovascularization in the retinal tissue., Significance: Supplementation with calcium seems to constrain inveterate symptoms of neovascular AMD by inhibiting inflammation and angiogenesis in the laser-induced CNV mouse model., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background and Objective: Age-related macular degeneration (AMD) is the leading cause of irreversible blindness among the elderly in developed countries. Subthreshold retinal laser therapy is a new technique that targets drusen - a marker of nonexudative AMD - without causing incidental retinal damage associated with conventional laser photocoagulation. This review summarizes published literature on subthreshold retinal laser therapy as prophylactic treatment of nonexudative AMD., Patients and Methods: A literature search of the PubMed, Medline, and Embase databases was conducted from January 1997 to April 2018. Studies were analyzed based upon study design, laser parameters, drusen reduction, changes in visual acuity (VA), and the development of choroidal neovascularization (CNV) and/or geographic atrophy (GA)., Results: Twelve studies involving 2,481 eyes treated with subthreshold retinal laser therapy were included in this review. Treatment led to increased drusen reduction, and studies with significant VA improvement were associated with significant drusen reduction. There was no significant change in the risk of developing CNV or GA., Conclusions: Subthreshold retinal laser therapy is effective for reducing drusen and potentially improving vision in patients with nonexudative AMD. This therapy does not show benefits in reducing development of CNV or GA. Thus, its long-term efficacy to prevent progression to advanced AMD cannot yet be recommended. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e61-e70.]., (Copyright 2019, SLACK Incorporated.)

Our previous investigations have shown that bone marrow-derived cells (BMCs), including mesenchymal stem cells (MSCs), contribute to the development of choroidal neovascularization (CNV) as sources of cells and angiogenic factors. Two main steps for circulating BMCs to integrate into CNV lesions are extracellular matrix remodeling and consequential cell migration. MicroRNAs (miRNAs) were found to be involved in CNV development; however, little is known about whether miRNAs regulate the contribution of BMCs to CNV. In the present study, we found that the expression of miR-188-5p was decreased in cultured hypoxic MSCs and BMCs within laser-induced CNV in mice. Matrix metalloproteinase 2 (MMP-2) and MMP-13 were both discovered as targets of miR-188-5p by bioinformatics predictions and dual-luciferase reporter system. Accordingly, increased expression of MMP-2/13 was found in hypoxic MSCs and BMCs in CNV lesions. Furthermore, miR-188-5p mimic transfection caused downregulation of MMP-2/13 in hypoxic MSCs and decreased tube formation of co-cultured vascular endothelial cells. Intravitreal injections of a miR-188-5p agomir attenuated the severity of CNV and inhibited the migration of BMCs into CNV lesions in mice. Our study suggests that miR-188-5p regulates the contribution of BMCs to CNV development by targeting MMP-2/13-mediated extracellular matrix degeneration, and miR-188-5p serves as a therapeutic target to treat CNV-related diseases., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Choroidal neovascularization (CNV) is a type of wet age-related macular degeneration (AMD) which is a major cause of blindness in elder patients. Tumor necrosis factor receptor-associated factor 6 (TRAF6) promotes tumor angiogenesis via upregulating the expression of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF). Additionally, TRAF6 facilitates the inflammatory response in macrophages and microglia. Here, using mouse laser-induced CNV model and TRAF6 siRNA, the study shows that TRAF6 is a critical player in CNV. The expression of TRAF6, HIF-1α, and VEGF increased in the model. TFAF6 siRNA intravitreal (IVT) injection inhibited CNV formation, as well as expression of HIF-1α and VEGF, activation of macrophages and microglia. Together, our data suggest that TFAF6 inhibition reduces CNV formation via down-regulating expression of HIF-1α and VEGF and activation of macrophages and microglia, demonstrating the unique advantages of TRAF6 inhibition in the alleviation of AMD., (Copyright © 2018 Elsevier Inc. All rights reserved.)

choroidal neovascularization (CNV), a characteristic of wet age-related macular degeneration (AMD), causes severe vision loss among elderly patients. TANK-binding kinase 1 (TBK1) is a ubiquitously expressed serine-threonine kinase and is found to induce endothelial cells proliferation, represent a novel mediator of tumor angiogenesis and exert pro-inflammatory effect. However, the role of TBK1 in choroidal neovascularization has not been investigated so far. In this study, we found that the expression of TBK1 and VEGF was up-regulated in RF/6 A cells chemical hypoxia model and laser-induced mouse CNV model. Silencing of TBK1 suppressed the proliferation and tube formation activity of RF/6 A cells. Intravitreal injection of anti-TBK1 monoclonal antibody ameliorates CNV formation. Taken together, these findings exhibit a proangiogenic role for TBK1 via upregulating the expression of VEGF, and may suggest that TBK1 inhibition offers a unique and alternative method for prevention and treatment of AMD., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: We explored the protective effects of N-acetylcysteine (NAC) on chorioretinal damage induced by photodynamic therapy (PDT) in an experimental rat model of choroidal neovascularization (CNV)., Methods: Experimental CNV was induced by an argon laser in 24 Brown Norway rats 7 days prior to PDT. Commencing 1 day after CNV induction, 0.5 mL of NAC was orally administered daily to the NAC + group (12 rats), and 0.5 mL of normal saline to the NAC- group (12 rats). Diode laser treatment was delivered for 42 s (total energy, 25 J/cm2) to the left eye prior to verteporfin infusion (PDT-) and to the right eye 15-20 min after such infusion (PDT+). Fluorescein angiography was performed just prior to PDT and enucleation to evaluate fluorescein leakage and CNV closure. We compared the CNV thickness, PDT-induced apoptosis [evaluated via terminal dUTP nick-end labeling (TUNEL)], fluorescein angiographic data, and extents of immunohistofluorescent staining for cleaved caspase-3 and superoxide dismutase (SOD) between the two groups., Results: Fourteen days after diode laser treatment, the CNV closure rate was significantly higher in the PDT-treated than the control group. However, the CNV closure rates did not differ significantly between the NAC- and NAC + groups. The TUNEL activity (a measure of PDT-induced apoptosis) of retinal cells was higher in the NAC-/PDT + than the NAC+/PDT + group at 1, 3, 7, and 14 days. The cleaved caspase-3 and SOD levels were higher in the NAC-/PDT + than the NAC+/PDT + group at 3 and 7 days., Conclusions: PDT triggers oxygen radical-induced injury to, and apoptosis in, the retina. NAC may reduce PDT-induced damage to the retina without compromising the therapeutic efficacy of CNV., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The aryl hydrocarbon receptor (AhR) is a ligand activated transcription factor, initially discovered for its role in regulating xenobiotic metabolism. There is extensive evidence supporting a multi-faceted role for AhR, modulating physiological pathways important in cell health and disease. Recently we demonstrated that the AhR plays a role in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly. We found that loss of AhR exacerbates choroidal neovascular (CNV) lesion formation in a murine model. Herein we tested the therapeutic impact of AhR activation on CNV lesion formation and factors associated with aberrant neovascularization. We screened a panel of synthetic drugs and endogenous AhR ligands, assessed their ability to activate AhR in choroidal endothelial cells, and inhibit angiogenesis in vitro. Drugs with an anti-angiogenic profile were then administered to a murine model of CNV. Two compounds, leflunomide and flutamide, significantly inhibited CNV formation concurrent with positive modifying effects on angiogenesis, inflammation, extracellular matrix remodeling, and fibrosis. These results validate the role of the AhR pathway in regulating CNV pathogenesis, identify mechanisms of AhR-based therapies in the eye, and argue in favor of developing AhR as a drug target for the treatment of neovascular AMD., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Arg-1 + Ym-1 + M2-type macrophages play essential roles in the development of choroidal neovascularization (CNV). Thus, inhibition of M2-type macrophages may be effective in suppressing CNV. However, the potential mechanisms of macrophage polarization during development of CNV remain unclear. In this study, we report that microRNA-155 (miR-155) inhibited M2 polarization by targeting C/EBPβ in CNV model mice and in bone marrow-derived primary macrophages. Moreover, our data show that intravitreous injection of miR-155 mimics suppressed subretinal leakage and neovascularization. Therefore, we conclude that C/EBPβ plays a significant role in M2 macrophage polarization in CNV model, while miR-155 mimics could suppress CNV by inhibiting C/EBPβ activity and M2 macrophage polarization.

Purpose: Ocular neovascularization (NV) is a pathologic process characterized by the proliferation and infiltration of various types of cells such as RPE, glial, and endothelial cells, which interact with proangiogenic factors and inflammatory cytokines. Endocan is known to be enriched in retinal endothelial tip cells under hypoxia, but the effect of endocan on ocular NV progression is largely unknown. In this study, we investigated the role of endocan in the ocular NV pathologic process and the possible mechanisms involved., Methods: In the eyes of mice with oxygen-induced retinopathy (OIR); choroidal NV (CNV); and rhodopsin promoter (rho)/VEGF transgenic mice, endocan expression was assessed by quantitative real-time PCR (RT-PCR) and Western blot. In vivo, a specific functional antibody was used to neutralize endocan and ocular NV levels were evaluated by RT-PCR, Western blot and immunostaining of flat-mounts. In vitro, the effect of endocan on human retinal microvascular endothelial cell (HREC) tube formation was observed using a routine method., Results: Endocan was significantly elevated in these three experimental mice models. Endocan blockade with the neutralizer intravitreal injection not only suppressed the area of retinal, choroidal and subretinal NV, but also resulted in a decrease in several angiogenesis-associated molecules. Recombinant endocan protein (rhEndocan) was found to induce tube formation on HRECs directly., Conclusions: The current data suggest that endocan is a potential therapeutic or an additional target for retinal and subretinal NV diseases.

Objective: The incidence of blindness is increasing because of the increase in abnormal ocular neovascularization. Anti-VEGF (vascular endothelial growth factor) therapies have led to good results, although they are not a cure for the blindness. The purpose of this study was to determine what role HB-EGF (heparin-binding epidermal growth factor-like growth factor) plays in ocular angiogenesis., Approach and Results: We examined the role played by HB-EGF in ocular neovascularization in 2 animal models of neovascularization: laser-induced choroidal neovascularization (CNV) and oxygen-induced retinopathy. We also studied human retinal microvascular endothelial cells in culture. Our results showed that the neovascularization was decreased in both the CNV and oxygen-induced retinopathy models in HB-EGF conditional knockout mice compared with that in wild-type mice. Moreover, the expressions of HB-EGF and VEGF were increased after laser-induced CNV and oxygen-induced retinopathy, and their expression sites were located around the neovascular areas. Exposure of human retinal microvascular endothelial cells to HB-EGF and VEGF increased their proliferation and migration, and CRM-197 (cross-reactive material-197), an HB-EGF inhibitor, decreased the HB-EGF-induced and VEGF-induced cell proliferation and migration. VEGF increased the expression of HB-EGF mRNA. VEGF-dependent activation of EGFR (epidermal growth factor receptor)/ERK1/2 (extracellular signal-regulated kinase 1/2) signaling and cell proliferation of endothelial cells required stimulation of the ADAM17 (a disintegrin and metalloprotease) and ADAM12. CRM-197 decreased the grades of the fluorescein angiograms and size of the CNV areas in marmoset monkeys., Conclusions: These findings suggest that HB-EGF plays an important role in the development of CNV. Therefore, further investigations of HB-EGF are needed as a potential therapeutic target in the treatment of exudative age-related macular degeneration., (© 2017 American Heart Association, Inc.)