Long-Acting Microparticle Formulation of Griseofulvin for Ocular Neovascularization Therapy.

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.

Crocetin inhibits choroidal neovascularization in both in vitro and in vivo models.

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-1ß, 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.

Pathologic vs. protective roles of hypoxia-inducible factor 1 in RPE and photoreceptors in wet vs. dry age-related macular degeneration.

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.

Oral Metformin Inhibits Choroidal Neovascularization by Modulating the Gut-Retina Axis.

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.

Artesunate mitigates choroidal neovascularization and scar formation.

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.

Exercise alleviates neovascular age-related macular degeneration by inhibiting AIM2 inflammasome in myeloid cells.

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-1ß 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-1ß as potential targets for treating nvAMD patients and enhancing the efficacy of anti-VEGF monotherapy.

Licochalcone A alleviates laser-induced choroidal neovascularization by inhibiting the endothelial-mesenchymal transition via PI3K/AKT signaling pathway.

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.

Cytochrome P450 oxidase 2J inhibition suppresses choroidal neovascularization in mice.

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.

Suppression of myeloid PFKFB3-driven glycolysis protects mice from choroidal neovascularization.

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.

Intravitreal injection of EV11, a novel aryl ketone amide, inhibits choroidal neovascularization via AKT/ERK1/2 pathway.

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.

Ocular Trauma Caused by Confetti Cannons.

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.

RESVEGA, a Nutraceutical Omega-3/Resveratrol Supplementation, Reduces Angiogenesis in a Preclinical Mouse Model of Choroidal Neovascularization.

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.

Active Rap1-mediated inhibition of choroidal neovascularization requires interactions with IQGAP1 in choroidal endothelial cells.

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.

The Effect of Blue-Light Filtering Intraocular Lenses on the Development and Progression of Neovascular Age-Related Macular Degeneration.

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.

Fursultiamine Alleviates Choroidal Neovascularization by Suppressing Inflammation and Metabolic Reprogramming.

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-1ß, 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.

Laser and anti-vascular endothelial growth factor treatment for drusenoid pigment epithelial detachment in age-related macular degeneration.

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.

Triptolide-nanoliposome-APRPG, a novel sustained-release drug delivery system targeting vascular endothelial cells, enhances the inhibitory effects of triptolide on laser-induced choroidal neovascularization.

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 ±â€¯3.89 % vs 41.25 ±â€¯4.67 % vs 53.55 ±â€¯5.76 %), migration (62.60 ±â€¯8.88 vs 104.60 ±â€¯13.32 vs 147.00 ±â€¯13.15), and tube formation (681.26 ±â€¯108.15 vs 926.75 ±â€¯54.01 vs 1189.84 ±â€¯157.14) than TP-nanolip or free TP (all P < 0.05). Intravitreal injections of free TP (77588.10±7719.28 µm3), TP-nanolip (64628.23 ±â€¯5857.96 µm3), and TP-nanolip-APRPG (50880.34 ±â€¯6606.56 µm3) inhibited the development of CNV compared with the PBS control group (120338.07 ±â€¯17428.90 µm3) (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.

Ilimaquinone inhibits neovascular age-related macular degeneration through modulation of Wnt/ß-catenin and p53 pathways.

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/ß-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 ß-catenin and stabilization of p53 in vivo. Our findings demonstrate that IQ functions through regulation of p53 and Wnt/ß-catenin pathways with conceivable advantages over existing cytokine-targeted anti-angiogenic therapies.

CNTF Prevents Development of Outer Retinal Neovascularization Through Upregulation of CxCl10.

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.

Triptolide attenuates laser-induced choroidal neovascularization via M2 macrophage in a mouse model.

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 µm2, n = 5, P＜0.05) and 0.07 mg/kg BW (37,271 ± 25,182 µm2, n = 5, P＜0.001) significantly reduced CNV areas by 54.9 and 74.8 %, respectively, compared with PBS control (147,699 ± 112,900 µm2, 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.