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1.
Nat Commun ; 15(1): 3780, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38710714

ABSTRACT

Recombinant adeno-associated viruses (rAAVs) have emerged as promising gene therapy vectors due to their proven efficacy and safety in clinical applications. In non-human primates (NHPs), rAAVs are administered via suprachoroidal injection at a higher dose. However, high doses of rAAVs tend to increase additional safety risks. Here, we present a novel AAV capsid (AAVv128), which exhibits significantly enhanced transduction efficiency for photoreceptors and retinal pigment epithelial (RPE) cells, along with a broader distribution across the layers of retinal tissues in different animal models (mice, rabbits, and NHPs) following intraocular injection. Notably, the suprachoroidal delivery of AAVv128-anti-VEGF vector completely suppresses the Grade IV lesions in a laser-induced choroidal neovascularization (CNV) NHP model for neovascular age-related macular degeneration (nAMD). Furthermore, cryo-EM analysis at 2.1 Å resolution reveals that the critical residues of AAVv128 exhibit a more robust advantage in AAV binding, the nuclear uptake and endosome escaping. Collectively, our findings highlight the potential of AAVv128 as a next generation ocular gene therapy vector, particularly using the suprachoroidal delivery route.


Subject(s)
Choroidal Neovascularization , Dependovirus , Genetic Therapy , Genetic Vectors , Retinal Pigment Epithelium , Animals , Dependovirus/genetics , Genetic Vectors/genetics , Genetic Vectors/administration & dosage , Genetic Therapy/methods , Mice , Retinal Pigment Epithelium/metabolism , Retinal Pigment Epithelium/virology , Choroidal Neovascularization/therapy , Choroidal Neovascularization/genetics , Rabbits , Humans , Gene Transfer Techniques , Macular Degeneration/therapy , Macular Degeneration/genetics , Macular Degeneration/pathology , Disease Models, Animal , Capsid Proteins/genetics , Capsid Proteins/metabolism , Transduction, Genetic , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Mice, Inbred C57BL , Retina/metabolism , Retina/virology , Male , HEK293 Cells
2.
Biomaterials ; 304: 122403, 2024 01.
Article in English | MEDLINE | ID: mdl-38016335

ABSTRACT

Gene therapy has been adapted, from the laboratory to the clinic, to treat retinopathies. In contrast to subretinal route, intravitreal delivery of AAV vectors displays the advantage of bypassing surgical injuries, but the viral particles are more prone to be nullified by the host neutralizing factors. To minimize such suppression of therapeutic effect, especially in terms of AAV2 and its derivatives, we introduced three serine-to-glycine mutations, based on the phosphorylation sites identified by mass spectrum analysis, to the XL32 capsid to generate a novel serotype named AAVYC5. Via intravitreal administration, AAVYC5 was transduced more effectively into multiple retinal layers compared with AAV2 and XL32. AAVYC5 also enabled successful delivery of anti-angiogenic molecules to rescue laser-induced choroidal neovascularization and astrogliosis in mice and non-human primates. Furthermore, we detected fewer neutralizing antibodies and binding IgG in human sera against AAVYC5 than those specific for AAV2 and XL32. Our results thus implicate this capsid-optimized AAVYC5 as a promising vector suitable for a wide population, particularly those with undesirable AAV2 seroreactivity.


Subject(s)
Capsid , Choroidal Neovascularization , Humans , Mice , Animals , Capsid/metabolism , Dependovirus/genetics , Serogroup , Transduction, Genetic , Choroidal Neovascularization/therapy , Tropism , Capsid Proteins/metabolism , Genetic Vectors/genetics
3.
Mol Ther ; 31(11): 3308-3321, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37752703

ABSTRACT

The upregulation of vascular endothelial growth factor (VEGF) is strongly associated with the development of choroidal neovascularization (CNV) in patients with neovascular age-related macular degeneration (nAMD). Currently, the standard treatment for nAMD involves frequent intravitreal injections of anti-VEGF agents, which inhibit the growth of new blood vessels and prevent leakage. However, this treatment regimen places a significant burden on patients, their families, and healthcare providers due to the need for repeated visits to the clinic for injections. Gene therapy, which enables the sustained expression of anti-VEGF proteins after a single injection, can dramatically reduce the treatment burden. KH631 is a recombinant adeno-associated virus 8 vector that encodes a human VEGF receptor fusion protein, and it is being developed as a long-term treatment for nAMD. In preclinical studies using non-human primates, subretinal administration of KH631 at a low dose of 3 × 108 vg/eye resulted in remarkable retention of the transgene product in the retina and prevented the formation and progression of grade IV CNV lesions. Furthermore, sustained transgene expression was observed for more than 96 weeks. These findings suggest that a single subretinal injection of KH631 has the potential to offer a one-time, low-dose treatment for nAMD patients.


Subject(s)
Choroidal Neovascularization , Macular Degeneration , Animals , Humans , Vascular Endothelial Growth Factor A/metabolism , Retina/metabolism , Choroidal Neovascularization/genetics , Choroidal Neovascularization/therapy , Primates/genetics , Primates/metabolism , Intravitreal Injections , RNA , Macular Degeneration/pathology , Genetic Therapy/methods , Angiogenesis Inhibitors/pharmacology , Recombinant Fusion Proteins
5.
Transl Vis Sci Technol ; 12(7): 17, 2023 07 03.
Article in English | MEDLINE | ID: mdl-37462980

ABSTRACT

Purpose: Risk for developing age-related macular degeneration (AMD) is linked to an overactive complement system. In the mouse model of laser-induced choroidal neovascularization (CNV), elevated levels of complement effector molecules, including complement C3, have been identified, and the alternative pathway (AP) is required for pathology. The main soluble AP regular is complement factor H (fH). We have previously shown that AP inhibition via subretinal AAV-mediated delivery of CR2-fH using a constitutive promoter is efficacious in reducing CNV. Here we ask whether the C3 promoter (pC3) effectively drives CR2-fH bioavailability for gene therapy. Methods: Truncated pC3 was used to generate plasmids pC3-mCherry/CR2-fH followed by production of corresponding AAV5 vectors. pC3 activation was determined in transiently transfected ARPE-19 cells stimulated with H2O2 or normal human serum (+/- antioxidant or humanized CR2-fH, respectively). CNV was analyzed in C57BL/6J mice treated subretinally with AAV5-pC3-mCherry/CR2-fH using imaging (optical coherence tomography [OCT] and fundus imaging), functional (electroretinography [ERG]), and molecular (protein expression) readouts. Results: Modulation of pC3 in vitro is complement and oxidative stress dependent, as shown by mCherry fluorescence. AAV5-pC3-CR2-fH were identified as safe and effective using OCT and ERG. CR2-fH expression significantly reduced CNV compared to mCherry and was correlated with reduced levels of C3dg/C3d in the retinal pigment epithelium/choroid fraction. Conclusions: We conclude that complement-dependent regulation of AP inhibition ameliorates AMD pathology as effectively as using a constitutive promoter. Translational Relevance: The goal of anticomplement therapy is to restore homeostatic levels of complement activation, which might be more easily achievable using a self-regulating system.


Subject(s)
Choroidal Neovascularization , Wet Macular Degeneration , Mice , Animals , Humans , Complement Pathway, Alternative/genetics , Hydrogen Peroxide/pharmacology , Mice, Inbred C57BL , Disease Models, Animal , Choroidal Neovascularization/genetics , Choroidal Neovascularization/therapy , Wet Macular Degeneration/genetics , Wet Macular Degeneration/therapy
7.
Med Phys ; 50(6): 3661-3670, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37029733

ABSTRACT

BACKGROUND: Age-related macular degeneration (AMD) is a major cause of irreversible central vision loss. The main reason for lost vision due to AMD is choroidal neovascularization (CNV). In the clinic, current treatments for CNV include photodynamic therapy, laser photocoagulation, and anti-vascular endothelial growth factor (VEGF) therapy. PURPOSE: This study evaluates a novel treatment technique combining synchronized nanosecond laser pulses and ultrasound bursts, namely photo-mediated ultrasound therapy (PUT) as a potential treatment method for CNV, for its efficacy and safety in the treatment of CNV via the experiments in a clinically-relevant rabbit model in vivo. METHODS: CNV was created by subretinal injection of Matrigel and vascular endothelial growth factor (M&V) in 10 New Zealand white rabbits. Six rabbits were used in the PUT group. In the control groups, two rabbits were treated by laser-only, and two rabbits were treated by ultrasound-only. The treatment efficacy was evaluated through fundus photography and fluorescein angiography (FA) longitudinally for up to 4 weeks. Rabbits were sacrificed for histopathology 3 months after treatment to examine the safety of PUT. RESULTS: The fluorescein leakage on FA was quantified to longitudinally evaluate treatment outcome. Compared with baseline, the relative intensity index was reduced by 26.57% ± 8.66% at 3 days after treatment, 27.24% ± 6.21% at 1 week after treatment, 27.79% ± 2.61% at 2 weeks after treatment, and 32.12% ± 3.23% at 4 weeks after treatment, all with a statistically significant difference of p < 0.01. The comparison between the relative intensity indexes from the two control groups (laser-only treatment and ultrasound-only treatment) did not show any statistically significant difference at all time points. Safety evaluation at 3 months with histopathology demonstrated that the PUT did not result in morphologic changes to the neurosensory retina. CONCLUSIONS: This study introduces PUT for the first time for the treatment of CNV. The results demonstrated good efficacy and safety of PUT to treat CNV in a clinically-relevant rabbit model. With a single session of treatment, PUT can safely reduce the leakage of CNV for at least 1 month after treatment.


Subject(s)
Choroidal Neovascularization , Macular Degeneration , Ultrasonic Therapy , Animals , Rabbits , Endothelial Growth Factors , Visual Acuity , Choroidal Neovascularization/diagnostic imaging , Choroidal Neovascularization/therapy , Choroidal Neovascularization/etiology , Retina/diagnostic imaging , Retina/pathology , Macular Degeneration/pathology , Fluorescein Angiography/adverse effects
8.
Sci Rep ; 13(1): 3715, 2023 03 06.
Article in English | MEDLINE | ID: mdl-36878916

ABSTRACT

The CRISPR/Cas9 system easily edits target genes in various organisms and is used to treat human diseases. In most therapeutic CRISPR studies, ubiquitously expressed promoters, such as CMV, CAG, and EF1α, are used; however, gene editing is sometimes necessary only in specific cell types relevant to the disease. Therefore, we aimed to develop a retinal pigment epithelium (RPE)-specific CRISPR/Cas9 system. We developed a CRISPR/Cas9 system that operates only in retinal pigment epithelium (RPE) by expressing Cas9 under the RPE-specific vitelliform macular dystrophy 2 promoter (pVMD2). This RPE-specific CRISPR/pVMD2-Cas9 system was tested in human retinal organoid and mouse model. We confirmed that this system works specifically in the RPE of human retinal organoids and mouse retina. In addition, the RPE-specific Vegfa ablation using the novel CRISPR-pVMD2-Cas9 system caused regression of choroidal neovascularization (CNV) without unwanted knock-out in the neural retina in laser-induced CNV mice, which is a widely used animal model of neovascular age-related macular degeneration. RPE-specific Vegfa knock-out (KO) and ubiquitous Vegfa KO were comparable in the efficient regression of CNV. The promoter substituted, cell type-specific CRISPR/Cas9 systems can be used in specific 'target cell' therapy, which edits genes while reducing unwanted off- 'target cell' effects.


Subject(s)
Choroidal Neovascularization , Craniocerebral Trauma , Humans , Animals , Mice , Retinal Pigment Epithelium , CRISPR-Cas Systems , Choroidal Neovascularization/genetics , Choroidal Neovascularization/therapy , Retina , Disease Models, Animal , Vascular Endothelial Growth Factor A/genetics
9.
Semin Ophthalmol ; 38(4): 352-357, 2023 May.
Article in English | MEDLINE | ID: mdl-36987548

ABSTRACT

INTRODUCTION: There are few reports evaluating the treatment of pachychoroid neovasculopathy (PNV) in white patients. The purpose of this study is to analyze the results of a treat and extend regimen with aflibercept in white patients with PNV after 2 years of follow-up. METHODS: We performed a retrospective study in 31 eyes of 26 patients with PNV treated with a treat an extend regimen of intravitreal aflibercept. The mean age was 63,84 ± 7.92 years. There were 9 males (35%) and 17 females (65%). Best-corrected visual acuity (BCVA), central macular thickness (CMT), choroidal subfoveal thickness (CST), choroidal thickness (CT) under type 1 choroidal neovascularization (CNV), pigment epithelium detachment (PED) height, and presence of subretinal fluid (SRF), intraretinal fluid (IRF) and wet macula, were evaluated at baseline and after 3, 6, 12, and 24 months. RESULTS: BCVA remained stable during the follow-up (p 0.161). A significant diminution of CMT was found (p 0.001). Conversely, PED height diminution was not significative (p 0.260). CST and CT under type 1 CNV improved significantly during the follow-up (p 0.005 and 0.009, respectively). Also, wet macula improved after 24 months (p < .001). The average number of intravitreal injections was 12.34 ± 6.01. CONCLUSION: Treat and extend regimen with intravitreal aflibercept in white patients with PNV may be effective for improving CMT, CST, CT under type 1 CNV and wet macula, and to stabilize vision, with a personalized regimen of intravitreal injections.


Subject(s)
Choroidal Neovascularization , Receptors, Vascular Endothelial Growth Factor , Recombinant Fusion Proteins , White People , Humans , Male , Female , Retrospective Studies , Choroidal Neovascularization/therapy , Middle Aged , Aged , Receptors, Vascular Endothelial Growth Factor/therapeutic use , Recombinant Fusion Proteins/therapeutic use , Subretinal Fluid , Intravitreal Injections , Visual Acuity , Macula Lutea
10.
Cesk Slov Oftalmol ; 78(6): 320-324, 2022.
Article in English | MEDLINE | ID: mdl-36543599

ABSTRACT

AIM: Case report of choroidal neovascularization (CNV) detection in patient who was treated for bilateral retinoblastoma in early childhood. MATERIAL AND METHODS: Patient at 1.5 years of age treated for endophytic retinoblastoma stage 4 (according to the Reese-Ellsworth classification) bilaterally, with a positive mutation in the Rb1 gene. After undergoing bilateral retinal laser treatment and 6 cycles of systemic chemotherapy, the tumor remained inactive without other complications. At the age of 14, the boy developed visual impairment in his left eye with metamorphosis. Based on a local finding and other auxiliary examinations, he was diagnosed with CNV in the macular area at the interface of the tumor scar and the healthy retina of the left eye. RESULTS: After three applications of anti-VEGF (antibodies blocking vascular endothelial growth factor) substance intravitreally (bevacizumab 1.2 mg), there was a reduction in CNV and also an improvement in visual function.


Subject(s)
Choroidal Neovascularization , Retinal Neoplasms , Retinoblastoma , Male , Humans , Child, Preschool , Angiogenesis Inhibitors/therapeutic use , Vascular Endothelial Growth Factor A , Retinoblastoma/therapy , Retinoblastoma/drug therapy , Bevacizumab/therapeutic use , Choroidal Neovascularization/complications , Choroidal Neovascularization/therapy , Retinal Neoplasms/therapy , Retinal Neoplasms/drug therapy , Intravitreal Injections
11.
Curr Gene Ther ; 22(5): 417-426, 2022.
Article in English | MEDLINE | ID: mdl-35382718

ABSTRACT

BACKGROUND: Wet age-related macular degeneration (wAMD) is characterized by the presence of choroidal neovascularization (CNV). Although there are some clinical drugs targeting vascular endothelial growth factor (VEGF) and inhibiting CNV, two major side effects limit their application, including the excessive activity of anti-VEGF and frequent intraocular injections. To explore better treatment strategies, researchers developed a hypoxic modulator retinal pigment epithelium (RPE)- specific adeno-associated virus (AAV) vector expressing endostatin to inhibit CNV. However, the mechanism of endostatin is complex. Instead, soluble fms-like tyrosine kinase-1 (sFlt-1) can inhibit VEGF-induced angiogenesis through two simple and clear mechanisms, giving rise to sequestration of VEGF and forming an inactive heterodimer with the membrane-spanning isoforms of the VEGF receptor Flt-1 and kinase insert domain-containing receptor. OBJECTIVE: In this study, we chose sFlt-1 as a safer substitute to treat wAMD by inhibiting VEGFinduced angiogenesis. METHODS: The AAV2/8-Y733F-REG-RPE-sFlt-1 vector was delivered by intravitreal injection to the eyes of mice. AAV2/8-Y733F vector is a mutant of the AAV2/8 vector, and the REG-RPE promoter is a hypoxia-regulated RPE-specific promoter. Two animal models were used to evaluate the function of the vector. RESULTS: In the cobalt chloride-induced hypoxia model, the results demonstrated that the AAV2/8- Y733F-REG-RPE-sFlt-1 vector induced the expression of the sFlt-1 gene in RPE cells through hypoxia. In the laser-induced CNV model, the results demonstrated that the AAV2/8-Y733F-REG-RPE-sFlt- 1 vector reduced laser-induced CNV. CONCLUSION: Hypoxia regulated, RPE-specific AAV vector-mediated sFlt-1 gene is a hypoxiaregulated antiangiogenic vector for wAMD.


Subject(s)
Choroidal Neovascularization , Animals , Choroidal Neovascularization/drug therapy , Choroidal Neovascularization/therapy , Disease Models, Animal , Endostatins/genetics , Endostatins/metabolism , Endostatins/pharmacology , Genetic Therapy/methods , Hypoxia/metabolism , Hypoxia/therapy , Mice , Retinal Pigment Epithelium/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor A/pharmacology , Vascular Endothelial Growth Factor Receptor-1/genetics , Vascular Endothelial Growth Factor Receptor-1/metabolism , Vascular Endothelial Growth Factor Receptor-1/pharmacology
12.
Int J Mol Sci ; 22(21)2021 Nov 07.
Article in English | MEDLINE | ID: mdl-34769482

ABSTRACT

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly. Choroidal neovascularization (CNV) is the major pathologic feature of neovascular AMD. Oxidative damages and the ensuing chronic inflammation are representative of trigger events. Hydrogen gas (H2) has been demonstrated as an antioxidant and plays a role in the regulation of oxidative stress and inflammation. This experiment aimed to investigate the influence of H2 inhalation on a mouse model of CNV. METHODS: Laser was used to induce CNV formation. C57BL/6J mice were divided into five groups: the control group; the laser-only group; and the 2 h, 5 h, and 2.5 h/2.5 h groups that received laser and H2 inhalation (21% oxygen, 42% hydrogen, and 37% nitrogen mixture) for 2 h, 5 h, and 2.5 h twice every day, respectively. RESULTS: The severity of CNV leakage on fluorescence angiography showed a significant decrease in the H2 inhalation groups. The mRNA expression of hypoxia-inducible factor 1 alpha and its immediate downstream target vascular endothelial growth factor (VEGF) showed significant elevation after laser, and this elevation was suppressed in the H2 inhalation groups in an inhalation period length-related manner. The mRNA expression of cytokines, including tumor necrosis factor alpha and interlukin-6, also represented similar results. CONCLUSION: H2 inhalation could alleviate CNV leakage in a laser-induced mouse CNV model, and the potential mechanism might be related to the suppression of the inflammatory process and VEGF-driven CNV formation.


Subject(s)
Anti-Inflammatory Agents/administration & dosage , Choroidal Neovascularization/therapy , Hydrogen/administration & dosage , Wet Macular Degeneration/therapy , Administration, Inhalation , Angiogenesis Inhibitors/administration & dosage , Angiogenesis Inhibitors/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Choroidal Neovascularization/etiology , Choroidal Neovascularization/pathology , Disease Models, Animal , Fluorescein Angiography , Fundus Oculi , Gases , Hydrogen/pharmacology , Lasers , Macular Degeneration/etiology , Macular Degeneration/pathology , Macular Degeneration/therapy , Mice , Mice, Inbred C57BL , Wet Macular Degeneration/etiology , Wet Macular Degeneration/pathology
13.
Sci Rep ; 11(1): 18084, 2021 09 10.
Article in English | MEDLINE | ID: mdl-34508129

ABSTRACT

Neovascular age-related macular degeneration (nAMD) commonly causes vision loss from aberrant angiogenesis, termed choroidal neovascularization (CNV). Interleukin-6 (IL6) is a pro-inflammatory and pro-angiogenic cytokine that is correlated with AMD progression and nAMD activity. We hypothesize that anti-IL6 therapy is a potential nAMD therapeutic. We found that IL6 levels were increased after laser injury and expressed by macrophages. Il6-deficiency decreased laser-induced CNV area and exogenous IL6 addition increased choroidal sprouting angiogenesis. Il6-null mice demonstrated equally increased macrophage numbers as wildtype mice. At steady state, IL6R expression was detected on peripheral blood and ocular monocytes. After laser injury, the number of IL6R+Ly6C+ monocytes in blood and IL6R+ macrophages in the eye were increased. In human choroid, macrophages expressed IL6, IL6R, and IL6ST. Furthermore, IL6R+ macrophages displayed a transcriptional profile consistent with STAT3 (signal transducer and activator of transcription 3) activation and angiogenesis. Our data show that IL6 is both necessary and sufficient for choroidal angiogenesis. Macrophage-derived IL6 may stimulate choroidal angiogenesis via classical activation of IL6R+ macrophages, which then stimulate angiogenesis. Targeting IL6 or the IL6R could be an effective adjunctive therapy for treatment-resistant nAMD patients.


Subject(s)
Choroid/blood supply , Choroid/metabolism , Choroidal Neovascularization/etiology , Choroidal Neovascularization/metabolism , Interleukin-6/metabolism , Macrophages/metabolism , Animals , Biomarkers , Choroid/pathology , Choroidal Neovascularization/pathology , Choroidal Neovascularization/therapy , Disease Models, Animal , Disease Susceptibility , Humans , Mice , Monocytes/metabolism , Receptors, Interleukin-6/metabolism
14.
Medicine (Baltimore) ; 100(34): e26980, 2021 Aug 27.
Article in English | MEDLINE | ID: mdl-34449466

ABSTRACT

ABSTRACT: Chronic central serous chorioretinopathy (CSC) can be complicated with choroidal neovascularization (CNV); however, the timing of its occurrence and its clinical significance are not well understood. This study aimed to observe the time of choroidal neovascularization detection after CSC diagnosis and determine whether clinical features and prognosis differed in patients with chronic CSC or age-related retinal degeneration.In this retrospective study, medical records of CSC patients complicated with CNV who visited Seoul St. Mary's hospital of Korea between October 2009 and December 2020 were reviewed. The presence of CNV was determined using fluorescein, indocyanine green, or optical coherent tomography angiography (OCTA). Based on the patients' medical records, we observed the change of clinical pattern, best-corrected visual acuity (BCVA) and central macular thickness (CMT) at CNV detection and at 6 months, 1 year, 3 years, and 5 years following CNV detection.Thirty eyes of 30 patients (male: female ratio of 13:17) were enrolled. Mean age at diagnosis of CSC was 54.0 ±â€Š8.5 years (mean ±â€Šstandard deviation). On average, CNV was detected 1.65 ±â€Š2.30 years after the diagnosis of CSC. The mean CMT was significantly decreased at 6 months, 1 year, and 3 years after choroidal neovascularization detection (P < .001, P < .001, P = .001 respectively). BCVA tend to improve after CNV detection, but there was no statistical significance at 6 months, 1 year, 3 years, and 5 years (all with P > .05). There were no clinical findings suggesting age-related macular degeneration such as intraretinal, subretinal hemorrhage or drusen in any of the case during follow-up. None of the subjects had severe visual acuity loss of 1.0 logarithm of the minimum angle of resolution (logMAR) (20/200 Snellen equivalent) or greater. Among the subjects, 6 patients (20%) did not require any treatment during observation, while 24 other patients required anti-vascular endothelial growth factor (anti-VEGF) or photodynamic therapy. At the last visit, 22 patients (73.3%) remained stable for more than 6 months, without subretinal fluid recurrence.Choroidal neovascularization was detected earlier than previously reported. There was no rapid deterioration of visual acuity or clinical features even after CNV detection.


Subject(s)
Central Serous Chorioretinopathy/complications , Choroidal Neovascularization/etiology , Aged , Central Serous Chorioretinopathy/pathology , Central Serous Chorioretinopathy/therapy , Choroidal Neovascularization/pathology , Choroidal Neovascularization/therapy , Female , Fluorescein Angiography , Humans , Male , Middle Aged , Photochemotherapy , Republic of Korea , Retrospective Studies , Time Factors , Vascular Endothelial Growth Factor A/antagonists & inhibitors
15.
Nat Biomed Eng ; 5(9): 968-982, 2021 09.
Article in English | MEDLINE | ID: mdl-34312509

ABSTRACT

Choroidal neovascularization induced by age-related macular degeneration and retinal neovascularization induced by diabetic retinopathy-two leading causes of blindness-are often treated using antibodies targeting vascular endothelial growth factor (VEGF). Here we report a strong association between inflammation and high VEGF expression in aqueous humour samples from patients with choroidal or retinal neovascularization, and show that intravitreally injected exosomes derived from regulatory T cells and conjugated with an anti-VEGF antibody via a peptide linker that is cleavable by matrix metalloproteinases markedly suppressed ocular neovascularization in mouse and non-human primate models of choroidal neovascularization. The engineered exosomes, which selectively accumulate in the neovascularization lesions, could be adapted for other combination therapies of therapeutic antibodies and anti-inflammatory cargo.


Subject(s)
Choroidal Neovascularization , Exosomes , Animals , Choroidal Neovascularization/therapy , Humans , Mice , T-Lymphocytes, Regulatory , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
16.
Expert Opin Emerg Drugs ; 26(2): 193-207, 2021 06.
Article in English | MEDLINE | ID: mdl-34030572

ABSTRACT

INTRODUCTION: Age-related macular degeneration (AMD) is the leading cause of blindness in individuals over age 50 in developed countries. Current therapy for nonexudative AMD (neAMD) is aimed at modifying risk factors and vitamin supplementation to slow progression, while intravitreal anti-vascular endothelial factor (VEGF) injections are the mainstay for treatment of choroidal neovascularization in exudative AMD (eAMD). AREAS COVERED: Over the past decade, promising therapies have emerged that aim to improve the current standard of care for both diseases. Clinical trials for neAMD are investigating targets in the complement cascade, vitamin A metabolism, metformin, and tetracycline, whereas clinical trials for eAMD are aiming to decrease treatment burden through novel port delivery systems, increasing drug half-life, and targeting new sites of the VEGF cascade. Stem cell and gene therapy are also being evaluated for treatment of neAMD and eAMD. EXPERT OPINION: With an aging population, the need for effective, long term, low burden treatment options for AMD will be in increasingly high demand. Current investigations aim to address the shortcomings of current treatment options with breakthrough treatment approaches. Therapeutics in the pipeline hold promise for improving the treatment of AMD, and are on track for widespread use within the next decade.


Subject(s)
Biological Therapy/methods , Choroidal Neovascularization/therapy , Macular Degeneration/therapy , Angiogenesis Inhibitors/administration & dosage , Angiogenesis Inhibitors/pharmacology , Animals , Choroidal Neovascularization/pathology , Disease Progression , Genetic Therapy/methods , Humans , Intravitreal Injections , Macular Degeneration/pathology , Middle Aged , Risk Factors , Stem Cell Transplantation/methods , Vascular Endothelial Growth Factor A/antagonists & inhibitors
17.
Exp Eye Res ; 207: 108583, 2021 06.
Article in English | MEDLINE | ID: mdl-33878326

ABSTRACT

PURPOSE: Age-related macular degeneration is a slowly progressing disease. Studies have tied disease risk to an overactive complement system. We have previously demonstrated that pathology in two mouse models, the choroidal neovascularization (CNV) model and the smoke-induced ocular pathology (SIOP) model, can be reduced by specifically inhibiting the alternative complement pathway (AP). Here we report on the development of a novel injury-site targeted inhibitor of the alternative pathway, and its characterization in models of retinal degeneration. METHODS: Expression of the danger associated molecular pattern, a modified annexin IV, in injured ARPE-19 cells was confirmed by immunohistochemistry and complementation assays using B4 IgM mAb. Subsequently, a construct was prepared consisting of B4 single chain antibody (scFv) linked to a fragment of the alternative pathway inhibitor, fH (B4-scFv-fH). ARPE-19 cells stably expressing B4-scFv-fH were microencapsulated and administered intravitreally or subcutaneously into C57BL/6 J mice, followed by CNV induction or smoke exposure. Progression of CNV was analyzed using optical coherence tomography, and SIOP using structure-function analyses. B4-scFv-fH targeting and AP specificity was assessed by Western blot and binding experiments. RESULTS: B4-scFv-fH was secreted from encapsulated RPE and inhibited complement in RPE monolayers. B4-scFv-fH capsules reduced CNV and SIOP, and western blotting for breakdown products of C3α, IgM and IgG confirmed a reduction in complement activation and antibody binding in RPE/choroid. CONCLUSIONS: Data supports a role for natural antibodies and neoepitope expression in ocular disease, and describes a novel strategy to target AP-specific complement inhibition to diseased tissue in the eye. PRECIS: AMD risk is tied to an overactive complement system, and ocular injury is reduced by alternative pathway (AP) inhibition in experimental models. We developed a novel inhibitor of the AP that targets an injury-specific danger associated molecular pattern, and characterized it in disease models.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Complement Inactivating Agents/therapeutic use , Complement Pathway, Alternative/drug effects , Disease Models, Animal , Immunoglobulin M/immunology , Retinal Degeneration/therapy , Retinal Pigment Epithelium/metabolism , Animals , Blotting, Western , Cell Line , Cell- and Tissue-Based Therapy/methods , Choroidal Neovascularization/diagnostic imaging , Choroidal Neovascularization/immunology , Choroidal Neovascularization/therapy , Complement C3/antagonists & inhibitors , Complement C3/genetics , Drug Delivery Systems , Male , Mice , Mice, Inbred C57BL , Recombinant Fusion Proteins , Retinal Degeneration/diagnostic imaging , Retinal Degeneration/immunology , Tomography, Optical Coherence , Transfection
18.
J Ocul Pharmacol Ther ; 37(3): 181-190, 2021 04.
Article in English | MEDLINE | ID: mdl-33835848

ABSTRACT

Inhibition of vascular endothelial growth factor is the mode of action for several approved therapies, including aflibercept, for the treatment of neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME). Lack of compliance due to the frequent intravitreal dosing requirements may result in inadequately treated disease, leading to irreversible vision impairment. To date, the majority of gene therapy clinical trials providing sustained anti-VEGF levels in the retina have been limited to subretinal injections requiring a vitrectomy. A single intravitreal injection of a gene therapy product could drastically reduce the treatment burden and improve visual outcomes. ADVM-022, an adeno-associated virus vector encoding aflibercept, has been optimized for intravitreal delivery and strong protein expression. Long-term expression and efficacy of ADVM-022-derived aflibercept were evaluated in a laser-induced choroidal neovascularization (CNV) model in non-human primates. Ocular safety was evaluated following long-term suppression of VEGF by clinical scoring (inflammatory parameters) as well as optical coherence tomography (OCT) and electroretinography (ERG). Intravitreal administration of ADVM-022 was well tolerated and resulted in sustained aflibercept levels in ocular tissues. In addition, ADVM-022 administration 13 months before laser-induced CNV prevented the occurrence of clinically relevant CNV lesions, to the same degree as a bolus of aflibercept delivered at the time of laser. These results demonstrate that a single intravitreal administration of ADVM-022 may provide a safe and effective long-term treatment option for nAMD and DME, and may ultimately improve patients' visual outcomes. Clinical trials are currently underway, evaluating safety and efficacy following a single intravitreal injection of ADVM-022.


Subject(s)
Choroidal Neovascularization/therapy , Dependovirus/genetics , Diabetes Mellitus/therapy , Genetic Therapy , Macular Degeneration/therapy , Macular Edema/therapy , Dependovirus/isolation & purification , Vascular Endothelial Growth Factors/genetics
19.
Sci Rep ; 11(1): 470, 2021 01 11.
Article in English | MEDLINE | ID: mdl-33432090

ABSTRACT

Polypoidal choroidal vasculopathy (PCV) is a distinctive type of neovascular age-related macular degeneration prevalent in many Asian countries. However, there is still some controversy in how the subtypes of PCV are classified. This post-hoc study redefined the branching vascular network (BVN) and PCV subtypes through retrospective review of indocyanine green angiography (ICGA) and fluorescein angiography images from two observational studies (RENOWNED/REAL). Of the visual outcomes for each angiographic subtype and treatment pattern investigated, BVN was identified in 56.3% of PCV patients. The proportions and features of the re-defined PCV subtypes were 43.8%, 10.4%, and 45.8% for subtype A (without distinctive features of BVN), B (with BVN but no leakage), and C (with BVN and leakage), respectively. Subtype A had better visual outcomes when compared to subtype C. This possibly resulted from a better baseline visual acuity in subtype A. Moreover, combination therapy [photodynamic therapy plus anti-vascular endothelial growth factor (VEGF)] may lead to better visual improvement than mono-anti-VEGF treatment alone. This study provides the prevalence of PCV subtypes in Taiwan and may serve as a reference for PCV treatment strategies in a real-world setting, especially for the combination therapy and patients without distinctive features of BVN.


Subject(s)
Choroidal Neovascularization/therapy , Macular Degeneration/therapy , Photochemotherapy/methods , Vascular Endothelial Growth Factor A/administration & dosage , Aged , Choroidal Neovascularization/classification , Choroidal Neovascularization/diagnostic imaging , Choroidal Neovascularization/epidemiology , Combined Modality Therapy , Female , Fluorescein Angiography , Humans , Indocyanine Green , Macular Degeneration/classification , Macular Degeneration/diagnostic imaging , Macular Degeneration/epidemiology , Male , Middle Aged , Prevalence , Taiwan/epidemiology , Treatment Outcome
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