Search Results (173)

This study aimed to investigate the tyrosine kinase inhibitor Nintedanib and its potential role in reversing epithelial–mesenchymal transition (EMT) induced by transforming growth factor beta 2 (TGF-β2) in retinal pigment epithelial (RPE) cells, along with its therapeutic potential using a mouse model of subretinal fibrosis. We hypothesized that the blockade of angiogenesis promoting and fibrosis inducing signaling using the receptor tyrosine kinase inhibitor Nintedanib (OfevTM) can prevent or reverse EMT both in vitro and in our in vivo model of subretinal fibrosis. Primary human retinal pigment epithelial cells (phRPE) and adult retinal pigment epithelial cell line (ARPE-19) cells were treated with TGF-β210 ng/mL for two days followed by four days of Nintedanib (1 µM) incubation. Epithelial and mesenchymal phenotypes were assessed by morphological examination, quantitative real-time polymerase chain reaction(qPCR) (ZO-1, Acta2, FN, and Vim), and immunocytochemistry (ZO-1, vimentin, fibronectin, and αSMA). Metabolites were measured using luciferase-based assays. Extracellular acidification and oxygen consumption rates were measured using the Seahorse XF system. Metabolic-related genes (GLUT1, HK2, PFKFB3, CS, LDHA, LDHB) were evaluated by qPCR. A model of subretinal fibrosis using the two-stage laser-induced method in C57BL/6J mice assessed Nintedanib’s therapeutic potential. Fibro-vascular lesions were examined 10 days later via fluorescence angiography and immunohistochemistry. Both primary and ARPE-19 RPE stimulated with TGF-β2 upregulated expression of fibronectin, αSMA, and vimentin, and downregulation of ZO-1, consistent with morphological changes (i.e., elongation). Glucose consumption, lactate production, and glycolytic reserve were significantly increased in TGF-β2-treated cells, with upregulation of glycolysis-related genes (GLUT1, HK2, PFKFB3, CS). Nintedanib treatment reversed TGF-β2-induced EMT signatures, down-regulated glycolytic-related genes, and normalized glycolysis. Nintedanib intravitreal injection significantly reduced collagen-1+ fibrotic lesion size and Isolectin B4+ neovascularization and reduced vascular leakage in the two-stage laser-induced model of subretinal fibrosis. Nintedanib can induce Mesenchymal-to-Epithelial Transition (MET) in RPE cells and reduce subretinal fibrosis through metabolic reprogramming. Nintedanib can therefore potentially be repurposed to treat retinal fibrosis. Full article

Chronic kidney disease (CKD)-associated anemia is a global health concern and is linked to vascular and ocular complications. Hypoxia-inducible factor (HIF) stabilizers, or HIF prolyl hydroxylase inhibitors (PHIs), are promising candidates for the treatment of CKD-associated anemia. Since hypoxia and angiogenesis are involved in eye diseases, this study examined the effects of HIF-PHIs on metabolism and gene expression in retinal pigment epithelium (RPE) cells. Results revealed that PHIs differentially induced angiogenic (VEGFA, ANG) and glycolytic (PDK1, GLUT1) gene expression, with Roxadustat causing the strongest transcriptional changes. However, Roxadustat-induced angiogenic signals did not promote endothelial tube formation. Moreover, it did not induce oxidative stress, inflammation, or significant antioxidant gene responses in ARPE-19 cells. Roxadustat also reduced the inflammatory cytokine response to tumor necrosis factor-α, including IL-6, IL-8, and MCP-1, and did not exacerbate VEGF expression under high-glucose conditions. Overall, Roxadustat triggered complex gene expression changes without promoting inflammation or oxidative stress in RPE cells. Despite these findings, ophthalmologic monitoring is advised during PHI treatment in CKD patients receiving HIF-PHIs. Full article

Diabetic retinopathy (DR), a leading cause of blindness in working-age adults, arises from chronic hyperglycemia-induced oxidative stress, inflammation, and vascular dysfunction. Current therapies such as laser photocoagulation, intravitreal anti-vascular endothelial growth factor (VEGF) agents, and steroids target advanced stages but fail to prevent early neuronal and microvascular damage. Emerging evidence highlights oxidative stress as a key driver of DR pathogenesis, disrupting the blood-retinal barrier (BRB), promoting neurodegeneration and angiogenesis. Advances in imaging, particularly optical coherence tomography angiography (OCTA), enable earlier detection of neurodegeneration and microvascular changes, underscoring DR as a neurovascular disorder. Polyphenols, such as resveratrol, curcumin, and pterostilbene, exhibit multitarget antioxidant, anti-inflammatory, and anti-angiogenic effects, showing promise in preclinical and limited clinical studies. However, their low bioavailability limits therapeutic efficacy. Nanotechnology-based delivery systems enhance drug stability, tissue targeting, and sustained release, offering potential for early intervention. Future strategies should integrate antioxidant therapies and precision diagnostics to prevent early irreversible retinal damage in diabetic patients. Full article

Type 2 diabetes mellitus (T2DM) is a major public health concern that significantly increases the risk of diabetic retinopathy (DR), a leading cause of visual impairment worldwide. This study aimed to identify molecular markers of inflammation (INF) and angiogenesis (ANG) in the aqueous humor (AH) of patients with non-proliferative diabetic retinopathy (NPDR). We conducted an observational, multicenter, case–control study including 116 participants classified into T2DM with NPDR, T2DM without DR, and non-diabetic controls (SCG) undergoing cataract surgery. AH samples were collected intraoperatively and analyzed for 27 cytokines using multiplex immunoassay. Eighteen immune mediators were detected in AH samples, and several were significantly elevated in the NPDR group, including the interleukins (IL) -1β, -6, -8, -15, -17, as well as the granulocyte–macrophage colony stimulating factor (GM-CSF), basic fibroblast growth factor (bFGF), interferon gamma-induced protein (IP-10), macrophage inflammatory protein 1 beta (MIP-1b), monocyte chemoattractant protein-1 (MCP-1), regulated on activation, normal T cell-expressed and -secreted protein (RANTES), and the vascular endothelial growth factor (VEGF). These molecules are involved in retinal INF, blood–retinal barrier breakdown, and pathological neovascularization. Our findings reveal a distinct pro-INF and pro-ANG profile in the AH of NPDR patients, suggesting that these cytokines may serve as early diagnostic/prognostic biomarkers for DR. Targeting these molecules could provide novel therapeutic strategies to mitigate retinal damage and vision loss in diabetic patients. Full article

Age-related macular degeneration (AMD) is a progressive retinal disorder and a leading cause of irreversible blindness among elderly individuals, impacting millions of people globally. This review synthesizes the current understanding of the cellular and molecular signaling mechanisms driving AMD, with a focus on the distinct pathophysiological features of dry and wet AMD subtypes. Key mechanisms include oxidative stress, inflammation, lipid metabolism dysregulation, and immune dysregulation, all of which converge on the retinal pigment epithelium (RPE) as a central player in disease initiation and progression. In dry AMD, oxidative damage, mitochondrial dysfunction, and lipofuscin accumulation impair RPE function, contributing to drusen formation and geographic atrophy. In wet AMD, vascular endothelial growth factor-mediated angiogenesis, coupled with inflammation and endothelial metabolic reprogramming, drives choroidal neovascularization. This article integrates findings from multiomics approaches and highlights the potential of artificial intelligence in elucidating AMD pathogenesis and advancing personalized therapies. Future research directions emphasize targeting these molecular pathways to develop innovative treatments, offering hope for improved management of this debilitating condition. Full article

Pericytes, specialized mural cells surrounding microvessels, play a crucial role in maintaining vascular homeostasis and function across various organs, including the eye. These versatile cells regulate blood flow, support the integrity of the blood–retinal barrier, and contribute to angiogenesis. Recent advancements in molecular and cellular biology have revealed the heterogeneity of pericytes and their critical involvement in ocular physiology and pathology. This review provides a comprehensive analysis of pericyte functions in ocular health and their implications in diseases such as diabetic retinopathy, age-related macular degeneration, glaucoma, and retinal vein occlusion. Pericyte dysfunction is implicated in vascular instability, neurovascular coupling failure, inflammation, and pathological neovascularization, contributing to vision-threatening disorders. The review further explores recent findings on pericyte-targeted therapies, including pharmacological agents, gene therapy, and cell-based approaches, aiming to restore pericyte function and preserve ocular health. Full article

Ocular diseases including glaucoma, diabetic retinopathy and age-related macular degeneration represent a growing global health burden, with current treatments often providing only symptomatic relief. Through an integrated approach combining preclinical models, molecular biology, and clinical insights, this review synthesizes 25 years of my translational research to advance therapeutic strategies for these conditions. Key findings demonstrate the following: (1) the dual neuroprotective and intraocular pressure-lowering effects of natural compounds (EGCG, forskolin) in glaucoma models; (2) successful development of Uparant, a first-in-class peptide inhibitor of pathological angiogenesis with efficacy in retinal disease models; and (3) innovative drug delivery systems (melatonin nanomicelles, liposomal sprays) that enhance ocular bioavailability. Notably, some of these approaches have progressed to early-phase clinical trials, demonstrating translational potential. Significant challenges remain in optimizing sustained drug delivery and addressing the heterogeneity of ocular diseases through personalized approaches. Future directions include combinatorial therapies and the application of artificial intelligence for treatment optimization. Collectively, this work establishes a framework for developing multi-target therapies that address both the molecular mechanisms and clinical needs in ophthalmology. Full article

Diabetic retinopathy is a sight-threatening complication of diabetes mellitus, affecting millions of people worldwide. From a vascular perspective, diabetic retinopathy compromises the structure and function of the blood–retinal barrier, leading to aberrant angiogenesis and vascular leakage, with consequent loss of vision. This review will delve into the vascular abnormalities caused by diabetic retinopathy in the inner blood–retinal barrier, focusing primarily on retinal endothelial cells. It will then discuss how calcium signalling regulates inner blood–retina barrier function and dysfunction, how calcium channels contribute to the development of diabetic retinopathy, and how studying the components of the calcium toolkit may identify new therapeutic targets. 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

Myo/Nog cells play a pivotal role in ocular development and demonstrate a rapid response to stress and injury. This study investigates their behavior and distribution in a murine model of retinitis pigmentosa, specifically in C3H/HeJ mice, which exhibit photoreceptor degeneration due to a homozygous mutation in the Pde6brd1 gene. Retinal samples from C3H/HeJ and C57BL/6J mice were analyzed at postnatal weeks 2.5 to 6 using hematoxylin and eosin staining, immunofluorescence for brain-specific angiogenesis inhibitor 1 (BAI1) expressed in Myo/Nog cells, and TUNEL labeling for apoptotic cell detection. The results demonstrated a progressive thinning of the outer nuclear layer (ONL) in C3H mice, accompanied by a significant increase in Myo/Nog cell numbers. In normal retinas, Myo/Nog cells were primarily located in the inner nuclear and outer plexiform layers. However, in C3H/HeJ mice, they accumulated in the ONL near apoptotic photoreceptors and within the choroid. Notably, in these degenerative regions, Myo/Nog cells exhibited features of phagocytosis, suggesting a role in apoptotic cell clearance. Additionally, parallels between Myo/Nog cell responses in retinitis pigmentosa and models of oxygen-induced retinopathy, ocular hypertension, and light damage suggest that these cells may be leveraged for therapeutic purposes. Full article

Upregulation of leucine-rich alpha-2-glycoprotein-1 (LRG1) contributes to aberrant neovascularization in many different diseases. In contrast, LRG1 is not involved in developmental angiogenesis. Here, we investigated the vasculopathic properties of LRG1 by examining its effect on developing retinal blood vessels. By injecting recombinant protein or an expression vector into the mouse retina during vascular development, we showed that exogenous LRG1 reduces pericyte coverage and NG2 expression. It leads to diminished collagen IV sheathing, fewer adhesion and gap junctions, and reduced vessel calibre and vascular density. Moreover, in mouse retinae containing exogenous LRG1, the developing blood–retinal barrier remains more permeable with significantly higher numbers of transcytotic vesicles present in microvascular endothelial cells. These results reveal that exogeneous LRG1 is sufficient to interfere with the maturation of developing retinal vessels and drive vessel development towards a dysfunctional phenotype. These observations deliver further evidence that LRG1 is an angiopathic factor and highlight the therapeutic potential of blocking LRG1 in diseases characterized by pathogenic angiogenesis or vascular remodelling. Full article

Diabetic retinopathy (DR) is a significant microvascular consequence of diabetes mellitus (DM), resulting in visual impairment and blindness. Controlling hyperglycemia is essential for avoiding and alleviating diabetic retinopathy. Nutrients and natural compounds possessing hypoglycemic characteristics present promising supplementary approaches to conventional therapies. This review assesses the influence of nutrients and natural substances on glycemic regulation and their possible effects on diabetic retinopathy. Goal: To investigate and consolidate knowledge about nutrients and natural compounds exhibiting hypoglycemic properties and their processes in the prevention and management of diabetic retinopathy. Approaches: Extensive reviews were conducted on pertinent studies from databases including PubMed, Scopus, and Web of Science. Selection criteria encompassed papers that examined natural substances, nutrients, or dietary supplements exhibiting effects on blood glucose levels and pathways associated to diabetic retinopathy. Principal findings were encapsulated according to their mechanisms, efficacy, and safety. Outcomes: Numerous foods, including omega-3 fatty acids, vitamin D, and polyphenols (e.g., curcumin, resveratrol), have hypoglycemic properties by improving insulin sensitivity and diminishing oxidative stress. Natural substances like berberine, quercetin, and flavonoids demonstrate analogous effects, influencing pathways associated with inflammation, advanced glycation end products (AGEs), and angiogenesis, which are critical factors in the evolution of diabetic retinopathy (DR). The synergistic benefits of integrating natural medicines with conventional antidiabetic medications may enhance glycemic control and reduce retinal damage. The safety profiles of these therapies are predominantly positive; nonetheless, clinical trials are still constrained in both breadth and scale. Conclusions: Nutrients and natural compounds are promising supplementary approaches for glycemic regulation and the therapy of diabetic retinopathy. Additional research, encompassing extensive clinical studies, is required to substantiate their efficacy, determine optimal dose, and verify long-term safety. The use of these natural substances into clinical practice may improve comprehensive management of diabetes and associated consequences. Full article

The role of the mitogen-activated protein kinase (MAPK) pathway in choroidal neovascularization (CNV) remains unclear. This study investigates the involvement of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 pathways in CNV development, as well as the therapeutic potential of sprouty 2 (SPRY2), an MAPK inhibitor, in a laser-induced mouse model. The expressions of ERK, JNK, and p38 proteins were analyzed using Western blotting and immunostaining. Immunofluorescence imaging revealed increased p-ERK and p-JNK expression in the retina, retinal pigment epithelium (RPE), and choroid up to day 7. Co-immunostaining showed p-ERK colocalized with CD31, CD11b, F4/80, cytokeratin, and GFAP in the retina, while p-JNK and p-p38 were associated with angiogenesis and inflammation throughout the retina and choroid. Compared to aflibercept, SPRY2 administration significantly inhibited CNV lesions, endothelial proliferation, fibrosis, and apoptosis, while better-preserving RPE integrity. SPRY2-treated mice showed a stronger reduction in CNV-related inflammation, epithelial–mesenchymal transition, and photoreceptor apoptosis. These results highlight the MAPK pathway’s role in CNV pathogenesis, with ERK primarily mediating Müller cell gliosis and JNK, contributing to angiogenesis and inflammation. SPRY2 effectively suppressed CNV lesions, supporting its potential as a therapeutic target for CNV treatment via MAPK pathway modulation. Full article

We previously observed elevated plasma levels of citrulline and arginine in diabetic retinopathy patients compared to diabetic controls. We tested our hypothesis that citrulline plus arginine induces angiogenesis and increases permeability in retinal endothelial cells. Human retinal microvascular endothelial cells (HRMECs) were treated with citrulline, arginine, or citrulline + arginine, and angiogenesis was measured with cell proliferation, migration, and tube formation assays. Permeability was measured in HRMEC monolayers via trans-endothelial electrical resistance (TEER) and FITC-labeled dextran. We also measured arginase activity, arginase-1 and arginase-2 expression, protein expression and phosphorylation of endothelial nitric oxide synthase (eNOS), and nitric oxide (NO) production. Citrulline + arginine induced endothelial cell proliferation (p = 0.018), migration (p = 0.011), and tube formation (p = 0.0042). Citrulline + arginine also increased FITC-dextran flow-through (p = 1.5 × 10⁻⁵) and decreased TEER (p = 0.010). Citrulline + arginine had no effect on arginase activity, but it increased eNOS (p = 6.3 × 10⁻⁴) and phosphorylated eNOS (p = 0.029), as well as NO production (p = 0.025). Inhibiting eNOS prevented the increase in NO (p = 0.0092), inhibited citrulline + arginine-induced cell migration (p = 0.0080) and tube formation (p = 0.0092), and blocked citrulline + arginine-related alterations in FITC-dextran flow-through (p = 3.6 × 10⁻⁴) and TEER (p = 3.9 × 10⁻⁴). These data suggest that citrulline + arginine treatment induces angiogenesis and increases permeability in retinal endothelial cells by activating eNOS and increasing NO production. Full article