Search Results (268)

Age-related macular degeneration (AMD) is one of the leading causes of irreversible vision loss among the elderly, and is influenced by a combination of genetic and environmental risk factors. While genetic associations in AMD are well-established, the molecular mechanisms underlying disease onset and progression remain poorly understood. A growing body of evidence suggests that epigenetic modifications may serve as a potential missing link regulating gene–environment interactions. This review incorporates recent findings on DNA methylation, including both hypermethylation and hypomethylation patterns affecting genes such as silent mating type information regulation 2 homolog 1 (SIRT1), glutathione S-transferase isoform (GSTM), and SKI proto-oncogene (SKI), which may influence key pathophysiological drivers of AMD. We also examine histone modification patterns, chromatin accessibility, the status of long non-coding RNAs (lncRNAs) in AMD pathogenesis and in regulating pathways pertinent to the pathophysiology of the disease. While the field of ocular epigenetics remains in its infancy, accumulating evidence to date points to a burgeoning role for epigenetic regulation in AMD, pre-clinical studies have yielded promising findings for the prospect of epigenetics as a future therapeutic avenue. Full article

The extracellular matrix (ECM) is a collagen-based scaffold that provides structural support and regulates nutrient transport and cell signaling. ECM homeostasis depends on a dynamic balance between synthesis and degradation, the latter being primarily mediated by matrix metalloproteinases (MMPs). These enzymes are secreted as pro-forms and require activation to degrade ECM components. Their activity is modulated by tissue inhibitors of metalloproteinases (TIMPs). Aging disrupts this balance, leading to the accumulation of oxidized, cross-linked, and denatured matrix proteins, thereby impairing ECM function. Bruch’s membrane, a penta-laminated ECM structure in the eye, plays a critical role in supporting photoreceptor and retinal pigment epithelium (RPE) health. Its age-related thickening and decreased permeability are associated with impaired nutrient delivery and waste removal, contributing to the pathogenesis of age-related macular degeneration (AMD). In AMD, MMP dysfunction is characterized by the reduced activation and sequestration of MMPs, which further limits matrix turnover. This narrative review explores the structural and functional changes in Bruch’s membrane with aging, the role of MMPs in ECM degradation, and the relevance of these processes to AMD pathophysiology, highlighting emerging regulatory mechanisms and potential therapeutic targets. Full article

Degenerative retinal diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinitis pigmentosa (RP), are the leading causes of vision loss worldwide. Inflammation plays a crucial role in the pathogenesis of these diseases, with cytokines acting as key mediators of neuroinflammation, vascular dysfunction, and cellular degeneration. This review explores the complex role of cytokines in degenerative retinal diseases, highlighting their involvement in disease progression, cellular interactions, and potential therapeutic strategies. Understanding the cytokine network within the retina may provide novel insights into targeted interventions for these debilitating conditions. Full article

Recently, marketing authorizations were granted by the Federal Drug Administration (FDA) for pegcetacoplan and avacincaptad pegol, which inhibit C3 and C5 complement components, respectively. These two drugs were demonstrated to slow down the growth of atrophic areas in the retina. These authorizations represent a huge breakthrough for patients suffering from geographic atrophy (GA), the late stage of the dry form of Age-related Macular Degeneration (AMD). Until then, no treatment was available to treat this blinding disease. However, these two new compounds inhibiting the complement system are still not available for patients outside of the United States, and they are not devoid of drawbacks, including a poor effect on vision improvement, an increased risk of occurrence of the neovascular form of AMD and the burden of patients receiving recurrent intravitreal injections. Thus, the important medical need posed by GA remains incompletely answered, and new therapeutic options with alternative modes of action are still required. Oxidative stress and inflammation are two major potential targets to limit the progression of atrophic retinal lesions. Dimethyl fumarate, dimethyl itaconate and other activators of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) display antioxidants and immunomodulatory properties that have shown evidence of efficacy in in vitro and in vivo models of dry AMD. Tecfidera^®, whose active principle is dimethyl fumarate, is already commercialized for the treatment of autoimmune diseases such as multiple sclerosis and psoriasis. The aim of this review is to present the rationale and the design of the clinical trial we initiated to test the effectiveness and safety of repurposing Tecfidera^®, which could represent a new therapeutic alternative in patients with the dry form of AMD. Full article

Dry age-related macular degeneration (AMD) is a leading cause of vision loss in individuals over 50, yet no approved therapies exist for early or intermediate stages of the disease. Oxidative stress is a central driver of retinal degeneration in AMD, and sodium iodate (NaIO₃)-induced injury serves as a well-characterized model of oxidative damage to the retinal pigment epithelium (RPE) and photoreceptors. BMI1, a poly-comb group protein involved in DNA repair, mitochondrial function, and cellular renewal, has emerged as a promising therapeutic target for retinal neuroprotection. We evaluated the efficacy of AAV-mediated BMI1 gene delivery in murine models using two administration routes: subretinal (SR) and suprachoroidal (SC). AAV5.BMI1 (1 × 10⁹ vg/eye) was delivered SR in Balb/c mice and evaluated at 4 and 15 weeks post-injection. AAV8.BMI1 (5 × 10⁹ or 1 × 10¹⁰ vg/eye) was administered SC in C57BL/6 mice and assessed at 4 weeks. Control groups received BSS or AAV8.stuffer. Following NaIO₃ exposure, retinal structure and function were analyzed by optical coherence tomography (OCT), electroretinography (ERG), histology, and molecular assays. SC delivery of AAV8.BMI1 achieved the highest levels of retinal BMI1 expression with no evidence of local or systemic toxicity. Treated eyes showed dose-dependent preservation of outer nuclear layer (ONL) thickness and significantly improved ERG responses indicating structural and functional protection. These findings support SC AAV.BMI1 gene therapy as a promising, minimally invasive, and translatable approach for early intervention in intermediate AMD. Full article

Age-related macular degeneration (AMD) is a common cause of blindness worldwide, and it is projected to affect several million individuals by 2040. The human retinal pigment epithelium (hRPE) degenerates in dry AMD, prompting the need to develop stem cell therapies to replace the lost tissue by autologous transplantation and restore the visual function. Nevertheless, the molecular factors behind the hRPE cell fate determination have not been elucidated. Here we identify all molecular determinants of the hRPE cell fate identity by comprehensive and unbiased screening of predicted pioneer factors in the human genome: such TFs mediate coordinated transitions in chromatin accessibility and transcriptional outcome along three major stages of the hRPE genesis. Furthermore, we compile a complete census of all transcription factor-specific binding sites by footprinting analysis of the human epigenome along the RPE developmental trajectory. Gene regulatory networks were found to be involved in cellular responses to glucose and hypoxia, RPE nitrosative stress, type II epithelial-to-mesenchymal transition (EMT), and type III tumorigenic EMT, providing routes for therapeutic intervention on pleiotropic targets dysregulated in AMD, diabetic retinopathy, and cancer progression. Genome editing technologies may leverage this repository to devise functional screenings of regulatory elements and pharmacogenomic therapies in complex diseases, paving the way for strategies in precision medicine. Full article

Advanced glycation end-products (AGEs) and oxidative stress are recognized as central contributors to the pathogenesis of age-related or diabetic cataracts, diabetic retinopathy (DR), and age-related macular degeneration (AMD). These glycation-related diseases are characterized by impaired redox balance and decreased glutathione (GSH) levels. This review aims to examine the mechanistic links between AGEs and GSH depletion across ocular tissues by integrating in vitro, ex vivo, in vivo, and clinical studies relevant to this topic. The multiple levels of evidence highlight GSH homeostasis as both a biomarker and therapeutic target in glycation-related ocular disorders. Therapeutic strategies aimed at restoring GSH homeostasis under glycation stress are categorized into four mechanistic domains: (I) promoting GSH supply and synthesis, (II) enhancing GSH recycling, (III) mitigating glycation stress, and (IV) reducing oxidative and nitrosative stress. Most of these strategies have been explored via different approaches, and experimental findings with various interventions have shown promise in restoring GSH balance and mitigating AGE-induced damage. A pathological link between GSH depletion and vascular endothelial growth factor (VEGF) overexpression is observed in DR and wet AMD. GSH-centered interventions act upstream to modulate redox homeostasis while anti-VEGF therapies target downstream angiogenesis. This study supports the rationale for a dual-targeting strategy that combines redox-based interventions with VEGF inhibition in glycation-related ocular diseases. Full article

Background: This study pioneers the exploration of the role of cuproptosis (a novel form of regulated cell death) in the pathogenesis of atopic dermatitis (AD). Methods: We integrated two datasets (GSE157194 and GSE193309) from the GEO database and employed weighted gene co-expression network analysis (WGCNA) to identify disease-related modules. Through multi-dimensional approaches, including differential gene expression analysis, functional enrichment analysis, GeneMANIA network construction, GSEA/GSVA pathway enrichment analysis, and immune infiltration analysis, we systematically elucidated the regulatory mechanisms of cuproptosis-related genes (CRGs) in AD. Results: The findings reveal novel mechanisms underlying AD pathogenesis. We identified 14 co-expression modules and 1173 differentially expressed genes, among which SPTLC2, AMD1, and IGSF3 were identified as key hub genes (AUC > 0.75). In-depth mechanistic analysis uncovered critical pathophysiological features of AD, including significant enrichment in chemokine signaling pathways (p < 0.001) and copper-dependent metabolic reprogramming. Notably, immune infiltration analysis demonstrated abnormal activity in 20 out of 21 immune cell types, particularly Th2 cells and macrophages, which showed strong correlations with CRG expression patterns. These findings establish an innovative “metabolic checkpoint” model for AD progression, highlighting dysregulation of the sphingolipid-immune axis as a key pathogenic mechanism. Conclusions: This study provides novel evidence, suggesting a potential link between AD and copper metabolism dysregulation, and identifies several promising targets that may aid in diagnosis and treatment. Our findings contribute to the growing understanding of AD pathogenesis and hint at possible new therapeutic directions, including copper chelation or sphingolipid-modulating approaches for difficult-to-treat AD cases. The identified CRG signatures may serve as potential biomarkers and therapeutic targets for personalized management strategies of this complex skin disorder. Full article

Age-related macular degeneration (AMD), the leading cause of irreversible blindness worldwide, represents a complex neurodegenerative disorder whose pathogenesis remains elusive. At the core of AMD pathophysiology lies the retinal pigment epithelium (RPE), whose epithelial–mesenchymal transition (EMT) has emerged as a critical pathological mechanism driving disease progression. This transformative process, characterized by RPE cell dedifferentiation and subsequent extracellular matrix remodeling, is orchestrated through a sophisticated network of molecular interactions and cellular signaling cascades. Our review provides a comprehensive analysis of the molecular landscape underlying RPE EMT in AMD, with particular emphasis on seven interconnected pathological axes: (i) oxidative stress and mitochondrial dysfunction, (ii) hypoxia-inducible factor signaling, (iii) autophagic flux dysregulation, (iv) chronic inflammatory responses, (v) complement system overactivation, (vi) epigenetic regulation through microRNA networks, and (vii) key developmental signaling pathway reactivation. Furthermore, we evaluate emerging therapeutic strategies targeting EMT modulation, providing a comprehensive perspective on potential interventions to halt AMD progression. By integrating current mechanistic insights with therapeutic prospects, this review aims to bridge the gap between fundamental research and clinical translation in AMD management. Full article

The process of aging exerts profound effects on various physiological systems, leading to the progression of chronic degenerative disorders and pathologies associated with advancing age. Cellular senescence plays a central role in the aging process and the onset of various eye conditions associated with advancing age, including age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, cataracts, and ocular surface disorders. The accumulation of senescent cells (SnCs) and their secretion of pro-inflammatory and tissue-remodeling factors, collectively known as the senescence-associated secretory phenotype (SASP), exacerbate chronic inflammation, oxidative stress, and tissue dysfunction, contributing to disease progression. This study is the first to systematically integrate the multifaceted mechanisms of cellular senescence in ocular diseases, revealing differential regulatory mechanisms of specific signaling pathways across different ocular pathologies, thereby providing novel insights into the pathogenesis of these disorders. SnC-targeted therapies such as senolytics, senomorphics, SASP modulators, mitochondrial-targeted antioxidants, and epigenetic reprogramming are emerging as regenerative therapies, demonstrating potent anti-inflammatory effects, restoration of normal tissue physiology, and successful regeneration of ocular defects in preclinical models and clinical trials, while slowing senescence-associated disease progression. This review not only summarizes the role of cellular senescence in ocular diseases but also delves into potential therapeutic strategies, particularly highlighting novel perspectives for root-cause-targeted therapies from the unique angle of senescence biology, which may pioneer new directions for the treatment of ocular pathologies. Full article

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis throughout the human body, influencing countless physiological and pathological processes, including tumor growth, preeclampsia, and retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). In DR, VEGF promotes retinal neovascularization and intraretinal fluid accumulation, leading to complications like diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR). Regular intravitreal anti-VEGF injections are commonly used to manage PDR and DME, though repeated treatments are often required, and efficacy can be limited. AMD, a major cause of vision loss in older adults, is characterized by either dry or wet forms. While the dry form has not been shown to be influenced by VEGF, the choroidal neovascularization of wet AMD has strong associations with VEGF. Current treatment for wet AMD consists primarily of anti-VEGF injections, the gold standard of care, but is limited by varying patient responses, as treatments are often repeated every 4-8 weeks indefinitely. This review explores the pathogenic role of VEGF in both DR and AMD, discussing the molecular mechanisms underlying these diseases and the therapeutic approaches targeting VEGF. Despite advancements, the variability in treatment responses highlights the need for continued research to develop more effective therapies to prevent vision loss and blindness associated with these retinal diseases. Full article

Age-related macular degeneration (AMD) is a multifactorial retinal disease influenced by complex molecular mechanisms, including genetic susceptibility, inflammation, oxidative stress, and metabolic dysregulation. While substantial progress has been made in understanding its pathogenesis, the full molecular underpinnings of AMD remain unclear, impeding the effectiveness of current therapeutic strategies. This study provides an in-depth exploration of the molecular interactions involved in AMD progression, particularly focusing on genetic predispositions (such as CFH, ARMS2/HTRA1, and APOE), inflammatory pathways (including complement system dysregulation and cytokine responses), lipid metabolism (e.g., cholesterol homeostasis and drusen formation), and angiogenesis (VEGF signaling). Through a systematic review and bibliometric analysis of literature published between 2015 and 2025, the study identifies emerging research trends, existing gaps, and promising future therapeutic directions. It further investigates innovative precision medicine approaches, including gene editing (CRISPR), RNA therapeutics (siRNA, antisense oligonucleotides), immunomodulatory therapies, and nanotechnology-based drug delivery systems. Additionally, the study examines the role of metabolic disorders such as diabetes and dyslipidemia in AMD progression, highlighting the influence of systemic health factors on disease onset. Finally, the potential of artificial intelligence (AI) in enhancing AMD management through biomarker-based risk stratification, predictive modeling, and personalized treatment optimization is assessed. By mapping the intricate molecular networks underlying AMD and evaluating novel therapeutic strategies, this research aims to contribute to the development of more effective, individualized treatment protocols for patients with AMD. Full article

Background/Objectives: Age-related macular degeneration (AMD) is the third leading cause of irreversible blindness in elderly individuals aged over 50 years old. Oxidative stress plays a crucial role in the etiopathogenesis of multifactorial AMD disease. The phospholipid bilayer EVs derived from the culture-conditioned medium of human induced pluripotent stem cell (hiPSC) differentiated retinal organoids aid in cell-to-cell communication, signaling, and extracellular matrix remodeling. The goal of the current study is to establish and evaluate the encapsulation of a hydrophobic compound, cannabidiol (CBD), into retinal organoid-derived extracellular vesicles (EVs) for potential therapeutic use in AMD. Methods: hiPSC-derived retinal organoid EVs were encapsulated with CBD via sonication (CBD-EVs), and structural features were elucidated using atomic force microscopy, nanoparticle tracking analysis, and small/microRNA (miRNA) sequencing. ARPE-19 cells and oxidative-stressed (H₂O₂) ARPE-19 cells treated with CBD-EVs were assessed for cytotoxicity, apoptosis (MTT assay), reactive oxygen species (DCFDA), and antioxidant proteins (immunohistochemistry and Western blot). Results: Distinct miRNA cargo were identified in early and late retinal organoid-derived EVs, implicating their roles in retinal development, differentiation, and functionality. The therapeutic effects of CBD-loaded EVs on oxidative-stressed ARPE-19 cells showed greater viability, decreased ROS production, downregulated expression of inflammation- and apoptosis-related proteins, and upregulated expression of antioxidants by Western blot and immunocytochemistry. Conclusions: miRNAs are both prognostic and predictive biomarkers and can be a target for developing therapy since they regulate RPE physiology and diseases. Our findings indicate that CBD-EVs could potentially alleviate the course of AMD by activating the targeted proteins linked to the adenosine monophosphate kinase (AMPK) pathway. Implicating the use of CBD-EVs represents a novel frontline to promote long-term abstinence from drugs and pharmacotherapy development in treating AMD. Full article

Background/Objectives: Exudative age-related macular degeneration (AMD) is a disease of choroidal neovascularization that causes blindness. Current treatments to preserve vision in this prevalent and blinding condition are repeat intraocular injections of anti-vascular endothelial growth factor medicines for a patient’s lifetime to preserve and prevent vision loss leading to blindness. Rifampicin, a small-molecule antibiotic, has previously been reported to exhibit anti-angiogenic properties and a topical safety profile that is well-tolerated. Based on this evidence, we investigated the feasibility of formulating rifamycin as an ophthalmic drop capable of delivering therapeutic concentrations to the posterior segment of the eye. Methods: Inhibition of neovascularization by administration of rifampicin was analyzed in the rat oxygen-induced retinopathy (OIR) and mouse laser-induced choroidal neovascularization (CNV) models. Pharmacokinetic (PK) studies were conducted in mice, rats, and rabbits by dosing various formulations containing rifampicin, and the compound was quantified by LC/MS analysis. Results: Results from dose escalation studies in the mouse laser-induced CNV model suggested the minimum effective dose of rifampicin required for inhibiting neovascularization in subretinal tissues to be 0.7 mg/kg, which is substantially lower than the 20 mg/kg dosage approved for infectious disease treatments. The previous studies did not report the minimum effective dose in the anti-angiogenesis effects. The effective area under the concentration-time curve (AUC) in the sub-retina was evaluated as 0.27 h·ng/mg. In rabbits, rifampicin was delivered to the sub-retina by a single topical application of various formulations in a dose-dependent manner. The topical application of the formulations containing 1% rifampicin, which was well-tolerated in clinical trials previously reported for ocular trachoma, achieved subretinal delivery approximately 2–32 times greater than the effective AUC. Plasma exposure of the compound by the topical application was evaluated to range approximately 0.5–10 ng/mL. Conclusions: Rifampicin was delivered to the sub-retina in rabbits with an efficiency greater than the effective dose required for inhibiting neovascularization. Limited amounts of plasma exposure by the topical application were detected. These results suggested the therapeutic potential of the rifampicin formulations for the topical treatment of exudative macular degeneration. Full article

Iron homeostasis plays an important role in maintaining cellular homeostasis; however, excessive iron can promote the production of reactive oxygen species (ROS). Ferroptosis is iron-dependent programmed cell death that is characterized by excessive iron accumulation, elevated lipid peroxides, and the overproduction of ROS. The maintenance of iron homeostasis is contingent upon the activity of the transferrin receptor (TfR), ferritin (Ft), and ferroportin (FPn). In the retina, iron accumulation and lipid peroxidation can contribute to the development of age-related macular degeneration (AMD). This phenomenon can be explained by the occurrence of the Fenton reaction, in which the interaction between divalent iron and hydrogen peroxide leads to the generation of highly reactive hydroxyl radicals. The hydroxyl radicals exhibit a propensity to attack proteins, lipids, nucleic acids, and carbohydrates, thereby instigating oxidative damage and promoting lipid peroxidation. Ultimately, these processes culminate in cell death and retinal degeneration. In this context, a comprehensive understanding of the exact mechanisms underlying ferroptosis may hold significant importance for developing therapeutic interventions. This review summarizes recent findings on iron metabolism, cellular ferroptosis, and lipid metabolism in the aging retina. We also introduce developments in the therapeutic strategies using iron chelating agents. Further refinements of these knowledges would deepen our comprehension of the pathophysiology of AMD and advance the clinical management of degenerative retinopathy. A comprehensive search strategy was employed to identify relevant studies on the role of ferroptosis in AMD. We performed systematic searches of the PubMed and Web of Science electronic databases from inception to the current date. The keywords used in the search included “ferroptosis”, “AMD”, “age-related macular degeneration”, “iron metabolism”, “oxidative stress”, and “ferroptosis pathways”. Peer-reviewed articles, including original research, reviews, meta-analyses, and clinical studies, were included in this paper, with a focus on the molecular mechanisms of ferroptosis in AMDs. Studies not directly related to ferroptosis, iron metabolism, or oxidative stress in the context of AMD were excluded. Furthermore, articles that lacked sufficient data or were not peer-reviewed (e.g., conference abstracts, editorials, or opinion pieces) were not considered. Full article