Seeing through VEGF: innate and adaptive immunity in pathological angiogenesis in the eye

Spatial transcriptomics reveals regionally altered gene expression that drives retinal degeneration

Photoreceptor cell death is a hallmark of age-related macular degeneration. Environmental, lifestyle and genetic risk factors are known contributors to disease progression, whilst at the molecular level, oxidative stress and inflammation are central pathogenetic drivers. However, the spatial and cellular origins of these molecular mechanisms remain unclear. We used spatial transcriptomics to investigate the spatio-temporal gene expression changes in the adult mouse retina in response to photo-oxidative stress. We identify regionally distinct transcriptomes, with higher expression of immunity related genes in the superior retina. Exposure to stress induced expression of genes involved in inflammatory processes, innate immune responses, and cytokine production in a highly localised manner. A distinct region ~800 µm superior from the optic nerve head seems a key driver of these molecular changes. Further, we show highly localised early molecular changes in the superior mouse retina during retinal stress and identify novel genes drivers. We provide evidence of angiogenic changes in response to photo-oxidative stress and suggest additional angiogenic signalling pathways within the retina including VEGF, pleiotrophin and midkine. These new insights into retinal angiogenesis pave the way to identify novel drivers of retinal neovascularisation with an opportunity for therapeutic development.

Phlorizin Protects Against Oxidative Stress and Inflammation in Age-Related Macular Degeneration Model

BACKGROUND

Sweet Tea (Lithocarpus polystachyus Rehd.), a traditional ethnobotanical medicine, contains phlorizin, a dihydrochalcone compound with antioxidative and anti-inflammatory properties. Given the critical role of oxidative stress and inflammation in age-related macular degeneration (AMD), this study tested the hypothesis that phlorizin mitigates oxidative damage and inflammation in AMD models, thereby offering therapeutic potential.

MATERIALS AND METHODS

Adult retinal pigmented epithelial cells (ARPE-19) were pre-treated with phlorizin (0.01-0.1 μM) and subjected to oxidative stress induced by ultraviolet A (UVA) radiation or sodium iodate (NaIO3). Cell viability, reactive oxygen species (ROS) production, MAPK/NF-κB signaling, and the level of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and pro-angiogenic factors (VEGF, MMP2, MMP9) expression were assessed using MTT assays, fluorescence imaging, Western blotting, and RT-qPCR. In vivo, a laser-induced choroidal neovascularization (CNV) mouse model was used to evaluate phlorizin's effects on CNV formation and vascular leakage via fundus photography and fluorescence angiography.

RESULT

Phlorizin significantly enhanced cell viability, reduced ROS production, inhibited MAPK/NF-κB activation, and downregulated inflammatory and angiogenic mediators. In vivo studies confirmed the reduced CNV formation and vascular leakage following the phlorizin treatment.

CONCLUSIONS

Phlorizin demonstrated significant protective effects against oxidative stress and inflammation, highlighting its therapeutic potential for treating AMD.

Protective effects of carotenoids against blue light induced-cellular damage in human retinal pigment epithelium

The retinal pigmented epithelium (RPE) is constantly exposed to visible light, including blue light (BL) that creates reactive oxygen species (ROS), which are harmful to DNA and induce cellular senescence. Carotenoids are recognized for their antioxidant properties, but their protective effect on DNA repair and cellular senescence under BL induced oxidative stress has not been evaluated. After BL irradiation, the positive senescence-associated-β-galactosidase (SA-β-gal) staining, and gene expression of p16 INK4a and p21 Waf/Cip1 were upregulated in ARPE-19 cells. Pretreatment with carotenoids reduced ROS, p-H2A.X nuclear foci, and SA-β-gal positive cells induced by BL irradiation. Furthermore, pretreatment with carotenoids reduced the secretion of IL-6 and VEGF triggered by BL. Since increased senescent cells and secretion of IL-6 and VEGF are involved in age-related macular degeneration pathogenesis, our results support that carotenoid supplementation has a potential role in protecting the eyes from the deleterious effects of excessive BL exposure.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01757-z.

The immunological perspective of major depressive disorder: unveiling the interactions between central and peripheral immune mechanisms

Major depressive disorder is a prevalent mental disorder, yet its pathogenesis remains poorly understood. Accumulating evidence implicates dysregulated immune mechanisms as key contributors to depressive disorders. This review elucidates the complex interplay between peripheral and central immune components underlying depressive disorder pathology. Peripherally, systemic inflammation, gut immune dysregulation, and immune dysfunction in organs including gut, liver, spleen and adipose tissue influence brain function through neural and molecular pathways. Within the central nervous system, aberrant microglial and astrocytes activation, cytokine imbalances, and compromised blood-brain barrier integrity propagate neuroinflammation, disrupting neurotransmission, impairing neuroplasticity, and promoting neuronal injury. The crosstalk between peripheral and central immunity creates a vicious cycle exacerbating depressive neuropathology. Unraveling these multifaceted immune-mediated mechanisms provides insights into major depressive disorder's pathogenic basis and potential biomarkers and targets. Modulating both peripheral and central immune responses represent a promising multidimensional therapeutic strategy.

The Landscape of Vascular Endothelial Growth Factor Inhibition in Retinal Diseases

Ever since the US Food and Drug Administration (FDA) approved the first vascular endothelial growth factor (VEGF) antagonist 2 decades ago, inhibitors of VEGF have revolutionized the treatment of a variety of ocular disorders involving pathologic neovascularization and retinal exudation. In this perspective, we evaluate the current status of anti-VEGF therapies and the real-world challenges encountered with maintaining therapeutic outcomes. Finally, we describe novel VEGF-based and combinatorial approaches that are in clinical development.

Mechanism and therapeutic targets of circulating immune cells in diabetic retinopathy

Diabetic retinopathy (DR) continues to be the leading cause of preventable vision loss among working-aged adults, marked by immune dysregulation within the retinal microenvironment. Typically, the retina is considered as an immune-privileged organ, where circulating immune cells are restricted from entry under normal conditions. However, during the progression of DR, this immune privilege is compromised as circulating immune cells breach the barrier and infiltrate the retina. Increasing evidence suggests that vascular and neuronal degeneration in DR is largely driven by the infiltration of immune cells, particularly neutrophils, monocyte-derived macrophages, and lymphocytes. This review delves into the mechanisms and therapeutic targets associated with these immune cell populations in DR, offering a promising and innovative approach to managing the disease.

Bioinformatics and Network Pharmacology Explore the Role of Immune Cells in the Occurrence of Anti-Vascular Endothelial Growth Factor (VEGF) Resistance in Patients with Neovascular Age-Related Macular Degeneration(nAMD) and the Application of Complementary Medicine Treatment

PURPOSE

This study explores the immune cells' role in anti-VEGF resistance in nAMD patients, and the potential of Zi-Yin-Jiang-Huo-Tang (ZYJHT), a Traditional Chinese Medicine formula, as complementary therapy.

METHODS

Aqueous humor proteomics data from 10 nAMD patients with anti-VEGF resistance and 10 nAMD patients without anti-VEGF resistance were analyzed, investigating immune cells's role in anti-VEGF resistance and its underlying mechanism. Network pharmacology methods are employed to analyze the active ingredients in ZYJHT that contribute to therapeutic effects and their mechanisms. Real-time PCR (polymerase chain reaction) was used to detect changes in the expression of SOD1 (superoxide dismutase 1) after treatment with compounds targeting SOD1 in ARPE-19 cells.

RESULTS

nAMD patients with anti-VEGF resistance showed enhancement of biological processes linked to the positive regulation of immune function, along with decreased cellular resistance to oxidative stress. Infiltration of B cells memory, plasma cells, CD8+and γδ-T cells were higher in nAMD patients with anti-VEGF resistance. SOD1 was identified as a hub gene in the occurrence of anti-VEGF resistance and a core therapeutic target of ZYJHT, negatively correlated with B and T cell infiltration. Compounds diosgenin, naringenin, and liquiritin in ZYJHT can bind to SOD1 and upregulating SOD1 expression in ARPE-19 cells.

Complement regulation in the eye: implications for age-related macular degeneration

Careful regulation of the complement system is critical for enabling complement proteins to titrate immune defense while also preventing collateral tissue damage from poorly controlled inflammation. In the eye, this balance between complement activity and inhibition is crucial, as a low level of basal complement activity is necessary to support ocular immune privilege, a prerequisite for maintaining vision. Dysregulated complement activation contributes to parainflammation, a low level of inflammation triggered by cellular damage that functions to reestablish homeostasis, or outright inflammation that disrupts the visual axis. Complement dysregulation has been implicated in many ocular diseases, including glaucoma, diabetic retinopathy, and age-related macular degeneration (AMD). In the last two decades, complement activity has been the focus of intense investigation in AMD pathogenesis, leading to the development of novel therapeutics for the treatment of atrophic AMD. This Review outlines recent advances and challenges, highlighting therapeutic approaches that have advanced to clinical trials, as well as providing a general overview of the complement system in the posterior segment of the eye and selected ocular diseases.

Human lens epithelial-secreted exosomes attenuate ocular angiogenesis via inhibiting microglial activation

The lens is an avascular tissue, where epithelial cells (LECs) are the primary living cells. The role of LECs-derived exosomes (LEC-exos) is largely unknown. In our study, we determined the anti-angiogenic role of LEC-exos, manifested as regressed retinal neovascularization (NV) using the oxygen-induced retinopathy (OIR), and reduced choroidal NV size and pathological vascular leakage using the laser-induced choroidal neovascularization (laser-induced CNV). Furthermore, the activation and accumulation of microglia were also restricted by LEC-exos. Based on Luminex multiplex assays, the expressions of chemokines such as SCYB16/CXCL16, MCP-1/CCL2, I-TAC/CXCL11, and MIP 3beta/CCL19 were decreased after treatment with LEC-exos. Transwell assays showed that LEC-exos restricted the migration of the mouse microglia cell line (BV2 cells). After incubation with LEC-exos-treated BV2 cells, human umbilical vein endothelial cells (hUVECs) were collected for further evaluation using tube formation, Transwell assays, and 5-ethynyl-2'-deoxyuridine (EDU) assays. Using in vitro experiments, the pro-angiogenic effect of microglia was restricted by LEC-exos. Hence, it was investigated that LEC-exos attenuated ocular NV, which might attribute to the inhibition of microglial activation and accumulation.

Mitigation of human iris angiogenesis through uPAR/LRP-1 interaction antagonism in an organotypic ex vivo model

Rubeosis Iridis (RI) is characterized by an increase in neovascularization and inflammation factors in the iris. During angiogenesis, the urokinase plasminogen activator (uPA) and its receptor (uPAR) play a pivotal role in extracellular matrix remodeling, where uPAR regulates endothelial cell migration and proliferation through assembly with transmembrane receptors. Here, in the context of hypoxia-induced angiogenesis, the uPA/uPAR system blockage was investigated by using UPARANT in a novel ex vivo human iris organotypic angiogenesis assay. The effects of uPA/uPAR system antagonism in the humanized model of ocular pathologic angiogenesis were analyzed by sprouting angiogenesis and protein assays (western, dot blots, and co-immunoprecipitation) and correlated to vascular endothelial growth factor (VEGF) inhibition. Phosphoprotein and co-immunoprecipitation assay illustrated an unidentified antagonism of UPARANT in the interaction of uPAR with the low-density lipoprotein receptor-related protein-1 (LRP-1), resulting in inhibition of β-catenin-mediated angiogenesis in this model. The effects of uPA/uPAR system inhibition were focal to endothelial cells ex vivo. Comparison between human iris endothelial cells and human retinal endothelial revealed an endothelial-specific mechanism of β-catenin-mediated angiogenesis inhibited by uPA/uPAR system blockage and not by VEGF inhibition. Collectively, these findings broaden the understanding of the effects of the uPA/uPAR system antagonism in the context of angiogenesis, revealing non-canonical β-catenin downstream effects mediated by LRP-1/uPAR interaction.

Retinal detachment

Retinal detachment (RD) occurs when the neurosensory retina, the neurovascular tissue responsible for phototransduction, is separated from the underlying retinal pigment epithelium (RPE). Given the importance of the RPE for optimal retinal function, RD invariably leads to decreased vision. There are three main types of RD: rhegmatogenous, tractional and exudative (also termed serous) RD. In rhegmatogenous RD, one or more retinal breaks enable vitreous fluid to enter the subretinal space and separate the neurosensory retina from the RPE. In tractional RD, preretinal, intraretinal or subretinal membranes contract and exert tangential forces and elevate the retina from the underlying RPE. Finally, in exudative RD, an underlying inflammatory condition, vascular abnormality or the presence of a tumour causes exudative fluid to accumulate in the subretinal space, exceeding the osmotic pump function of the RPE. The surgical management of RD usually involves pars plana vitrectomy, scleral buckling or pneumatic retinopexy. The approach taken often depends on patient characteristics as well as on practitioner experience and clinical judgement. Advances in surgical technology and continued innovation have improved outcomes for many patients. However, even if retinal re-attachment is achieved, some patients still experience decreased vision or other visual symptoms, such as metamorphopsia, that diminish their quality of life. Continued research in the areas of neuroprotection and retinal biology as well as continued surgical innovation are necessary to enhance therapeutic options and outcomes for these patients.

Cell-specific Systemic Immune Signatures Associated with Treatment Burden in Neovascular Age-related Macular Degeneration

Purpose

Choroidal neovascularization (CNV) accounts for the majority of severe vision loss in neovascular age-related macular degeneration (AMD). Despite therapies that target VEGF, patients are often under-responsive, require frequent eye injections to control disease, and eventually lose some vision despite chronic therapy implicating a multifactorial etiology in treatment response. Genetic studies implicate systemic immunity in AMD and systemic immune cells accumulate within CNV lesions, yet a role for these cells in anti-VEGF response remains undetermined. The purpose of this study was to identify transcriptional signatures of circulating immune cells that are associated with high anti-VEGF treatment burden.

Design

Experimental pilot study.

Participants

Patients with neovascular AMD seen at Washington University School of Medicine in St. Louis and BJC Health System.

Methods

We profiled by single cell RNA sequencing the peripheral blood mononuclear cells of 27 treatment-experienced patients with wet AMD. We stratified this cohort into 2 groups with low and high treatment burden (≤ 5 or ≥ 6 injections in the past 12 months, respectively).

Main Outcome Measures

Identification of immune cells associated with high treatment burden.

Results

Gene expression signature of CD16+ monocytes may be associated with high treatment burden.

Conclusions

These studies delineate potential signatures of circulating immune cells that may be associated with high treatment burden in neovascular AMD, potentially informing the development of diagnostic predictors of anti-VEGF response and new precision medicine-based approaches to complement anti-VEGF therapies.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Transfer RNA derived fragment, tRF-Glu-CTC, aggravates the development of neovascular age-related macular degeneration

Rationale: Angiogenesis expedites tissue impairment in many diseases, including age-related macular degeneration (AMD), a leading cause of irreversible blindness in elderly. A substantial proportion of neovascular AMD patients, characterized by aberrant choroidal neovascularization (CNV), exhibit poor responses or adverse reactions to anti-VEGF therapy. Herein, we aimed to unveil the function of newly identified transfer RNA-derived small RNA, tRF-Glu-CTC, in the pathology of CNV and determine its potential in inhibiting angiogenesis. Methods: Small non-coding RNA sequencing and quantitative polymerase chain reaction were conducted to detect expression pattern of tRF-Glu-CTC in CNV development. Immunofluorescence staining, fundus fluorescein angiography and ex vivo choroidal sprouting assays were employed for the evaluation of tRF-Glu-CTC's function in CNV development. The role of tRF-Glu-CTC in endothelial cells were determined by in vitro endothelial cell proliferation, migration and tube formation assays. Transcriptome sequencing, dual-luciferase reporter assay and in vitro experiments were conducted to investigate downstream mechanism of tRF-Glu-CTC mediated pathology. Results: tRF-Glu-CTC exhibited substantial up-regulation in AMD patients, laser-induced CNV model, and endothelial cells under hypoxia condition, which is a hallmark of CNV. Inhibiting tRF-Glu-CTC reduced angiogenesis and hypoxia stress in the neovascular region without neuroretina toxicity in laser-induced CNV model, showing an anti-angiogenic effect comparable to bevacizumab, while overexpression of tRF-Glu-CTC significantly augmented CNV. Mechanically, under hypoxia condition, angiogenin was involved in the production of tRF-Glu-CTC, which in turn triggered endothelial cell tubulogenesis, migration and promoted the secretion of inflammatory factors via the suppression of vasohibin 1 (VASH1). When downregulating VASH1 expression, the inhibition of tRF-Glu-CTC showed minimal suppression on angiogenesis. Conclusions: This study demonstrated the important role of tRF-Glu-CTC in the progression of angiogenesis. Targeting of tRF-Glu-CTC may be an alternative to current anti-VEGF therapy for CNV in AMD and other conditions with angiogenesis.

Targeting cell-type-specific, choroid-peripheral immune signaling to treat age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of blindness featuring pathogenic neovascularization of the choroidal vasculature (CNV). Although systemic immunity plays a role in AMD, the ocular signals that recruit and activate immune cells remain poorly defined. Using single-cell RNA sequencing, we prospectively profile peripheral blood mononuclear cells from 65 individuals including AMD and controls, which we integrate with existing choroid data. We generate a network of choroid-peripheral immune interactions dysregulated in AMD, including known AMD-relevant gene vascular endothelial growth factor (VEGF) receptor 2. Additionally, we find CYR61 is upregulated in choroidal veins and may signal to circulating monocytes. In mice, we validate that CYR61 is abundant in endothelial cells within CNV lesions neighboring monocyte-derived macrophages. Mechanistically, CYR61 activates macrophage anti-angiogenic gene expression, and ocular Cyr61 knockdown increases murine CNV size, indicating CYR61 inhibits CNV. This study highlights the potential of multi-tissue human datasets to identify disease-relevant and potentially therapeutically modifiable targets.

Comparative efficacy and safety of Faricimab and other anti-VEGF therapy for age-related macular degeneration and diabetic macular edema: A systematic review and meta-analysis of randomized clinical trials

INTRODUCTION

A systematic review and meta-analysis were conducted to evaluate the efficacy and the overall safety of Faricimab compared with other anti-vascular endothelial growth factors (VEGF) therapy for neovascular age-related macular degeneration (AMD) and diabetic macular edema (DME).

MATERIALS AND METHODS

A systematic literature search of a comprehensive electronic database was performed to identify randomized clinical trials published from January 2013 to January 2023 for Faricimab in AMD and DME. Weighted mean differences and risk ratios were used to integrate the different studies.

RESULTS

A total of 4 randomized controlled trials (RCTs) with 1678 AMD patients and 3 RCTs with 20 DME patients were included in the meta-analysis.In patients with AMD, a significant difference was found in the number of injections between Faricimab and other anti-VEGF therapy (MD = -2.42, 95% CI [-3.93 to -0.90], P = .002).No significant difference was found for the change in best corrected visual acuity (BVCA), central subfoveal thickness (CST), and gaining 15 or more letters. Similarly, no significant difference was found for adverse events.In patients with DME, a significant difference was observed for CST (MD = -22.41, 95% CI [-29.95 to -14.86], P < .00001) and the number of injections(MD = -0.93, 95% CI [-1.33 to -0.54], P < .00001). No significant difference was found for BVCA and gaining 15 or more letters, and no significant difference was found for adverse events.

CONCLUSIONS

Comprehensive evidence confirms that Faricimab achieves non-inferior or even better CST improvement than other anti-VEGF therapies with extended dosing intervals, but more long-term follow-up studies are needed to support our conclusions.

Efficient ocular delivery of siRNA via pH-sensitive vehicles for corneal neovascularization inhibition

Corneal neovascularization (CoNV)-induced blindness is an enduring and challenging condition with limited management options. Small interfering RNA (siRNA) is a promising strategy for preventing CoNV. This study reported a new strategy using siVEGFA to silence vascular endothelial growth factor A (VEGFA) for CoNV treatment. To improve the efficacy of siVEGFA delivery, a pH-sensitive polycationic mPEG_2k-PAMA₃₀-P(DEA₂₉-D5A₂₉) (TPPA) was fabricated. TPPA/siVEGFA polyplexes enter cells via clathrin-mediated endocytosis, resulting in higher cellular uptake efficiency and comparable silencing efficiency than that of Lipofectamine 2000 in vitro. Hemolytic assays verified that TPPA safe in normal physiological environments (pH 7.4) but can easily destroy membranes in acidic mature endosomes (pH 4.0). Studies on the distribution of TPPA in vivo showed that it could prolong the retention time of siVEGFA and promote its penetration in the cornea. In a mouse model induced by alkali burn, TPPA efficiently delivered siVEGFA to the lesion site and achieved VEGFA silencing efficiency. Importantly, the inhibitory effect of TPPA/siVEGFA on CoNV was comparable to that of the anti-VEGF drug ranibizumab. Delivering siRNA using pH-sensitive polycations to the ocular environment provides a new strategy to efficiently inhibit CoNV.

Dynamic changes in macrophage morphology during the progression of choroidal neovascularization in a laser-induced choroidal neovascularization mouse model

BACKGROUND

Neovascular age-related macular degeneration (AMD) is responsible for the majority of severe vision loss cases and is mainly caused by choroidal neovascularization (CNV). This condition persists or recurs in a subset of patients and regresses after 5 or more years of anti-vascular endothelial growth factor (VEGF) treatment. The precise mechanisms of CNV continue to be elucidated. According to our previous studies, macrophages play a critical role in CNV. Herein, we aimed to determine the morphological changes in macrophages in CNV to help us understand the dynamic changes.

METHODS

Mice were subjected to laser injury to induce CNV, and lesion expansion and macrophage transformation were examined by immunofluorescence and confocal analysis. Several strategies were used to verify the dynamic changes in macrophages. Immunofluorescence and confocal assays were performed on choroidal flat mounts to evaluate the morphology and phenotype of macrophages in different CNV phases, and the results were further verified by western blotting and RT-PCR.

RESULTS

The location of infiltrated macrophages changed after laser injury in the CNV mouse model, and macrophage morphology also dynamically changed. Branching macrophages gradually shifted to become round with the progression of CNV, which was certified to be an M2 phenotypic shift.

CONCLUSIONS

Dynamic changes in macrophage morphology were observed during CNV formation, and the round-shaped M2 phenotype could promote neovascularization. In general, the changes in morphology we observed in this study can help us to understand the critical role of macrophages in CNV progression and exploit a potential treatment option for CNV indicated by a shift in macrophage polarity.

Prevention of Inflammation, Neovascularization, and Retinal Dysfunction by Kinin B1 Receptor Antagonism in a Mouse Model of Age-Related Macular Degeneration

The kallikrein-kinin system (KKS) contributes to vascular inflammation and neovascularization in age-related macular degeneration (AMD), particularly via the kinin B1 receptor (B1R). The aim of the present study was to determine the protective effects of the topical administration of the B1R antagonist (R-954) on inflammation, neovascularization, and retinal dysfunction in a murine model of neovascular AMD. Choroidal neovascularization (CNV) was induced in C57BL6 mice using an argon laser. A treatment with ocular drops of R-954 (100 μg/15 μL, twice daily in both eyes), or vehicle, was started immediately on day 0, for 7, 14, or 21 days. CNV, invasive microglia, and B1R immunoreactive glial cells, as well as electroretinography alterations, were observed within the retina and choroid of the CNV group but not in the control group. The staining of B1R was abolished by R-954 treatment as well as the proliferation of microglia. R-954 treatment prevented the CNV development (volume: 20 ± 2 vs. 152 ± 5 × 104 µm3 in R-954 vs. saline treatment). R-954 also significantly decreased photoreceptor and bipolar cell dysfunction (a-wave amplitude: -47 ± 20 vs. -34 ± 14 µV and b-wave amplitude: 101 ± 27 vs. 64 ± 17 µV in R-954 vs. saline treatment, day 7) as well as angiogenesis tufts in the retina. These results suggest that self-administration of R-954 by eye-drop treatment could be a promising therapy in AMD to preserve retinal health and vision.

Neurotrophic basis to the pathogenesis of depression and phytotherapy

Depression is a major neuropsychiatric disease that considerably impacts individuals’ psychosocial function and life quality. Neurotrophic factors are now connected to the pathogenesis of depression, while the definitive neurotrophic basis remains elusive. Besides, phytotherapy is alternative to conventional antidepressants that may minimize undesirable adverse reactions. Thus, further research into the interaction between neurotrophic factors and depression and phytochemicals that repair neurotrophic factors deficit is highly required. This review highlighted the implication of neurotrophic factors in depression, with a focus on the brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF), and nerve growth factor (NGF), and detailed the antidepressant activities of various phytochemicals targeting neurotrophic factors. Additionally, we presented future opportunities for novel diagnostic and therapeutic strategies for depression and provided solutions to challenges in this area to accelerate the clinical translation of neurotrophic factors for the treatment of depression.

Physicochemical and Biological Stability Assessment of SB11 (Ranibizumab Biosimilar) Under Ambient and In-Use Storage for Intravitreal Administration

INTRODUCTION

SB11 (Byooviz™) is a ranibizumab biosimilar that acts as a vascular endothelial growth factor (VEGF)-A inhibitor. Stability data for unopened SB11 vials at room temperature are limited and no data are available for SB11 withdrawn into syringes (in-use) for intravitreal administration.

METHODS

SB11 stability was assessed in two different settings: unopened vials stored at 30 ± 2 °C/65 ± 5% relative humidity (RH) for 2 months, and in-use SB11 withdrawn into syringes stored at 5 ± 3 °C for 98 days and then 25 ± 2 °C/60 ± 5% RH for 24 h. The product was stored in the absence of light, and the experimental design followed International Conference on Harmonization and European Medicines Agency requirements for stability evaluation of biological products. Analysis included visual appearance (color, clarity, and presence of visible particles), pH, protein concentration (A₂₈₀) and purity (size-exclusion high-pressure liquid chromatography, capillary electrophoresis-sodium dodecyl sulfate, imaged capillary isoelectric focusing), biological activity (VEGF binding and neutralization), and safety (sub-visible particulates).

RESULTS

Except for charge variants in unopened vials at room temperature after 1 month by US standards, all results met the stability acceptance criteria (US and EU) for both unopened vials and for in-use SB11. There were no major changes in terms of physicochemical stability, biological activity and sub-visible particulates.

CONCLUSION

SB11 was stable for longer periods and at higher temperatures than what is stated in the labels of the reference product (Lucentis) and SB11. The physicochemical properties, biological activity, and sub-visible particulates of SB11 in both tested settings (unopened vials at room temperature and in-use product withdrawn into syringes) were maintained under the described storage periods. This information can help to avoid unnecessary delays in patient treatment without any loss in quality and biological activity, lower the workload of health care providers and reduce costs associated with drug waste.

Role of flavonoids in age-related macular degeneration

A common eye disorder known as age-related macular degeneration (AMD) eventually results in blindness and vision loss. AMD has a complicated and poorly understood aetiology. The main pathological processes associated with AMD include oxidative damage, inflammation, and neovascularization. Flavonoids are naturally occurring bioactive substances with extensive distribution and antioxidant, anti-inflammatory, and neovascularization inhibitory properties. Several in vitro and in vivo AMD-related models pertinent to vision and this ocular ailment have been used to assess the mechanisms of action of various flavonoids. This article will discuss the research progress of flavonoids in AMD, especially the characteristics and mechanism of flavonoids in treating AMD.

Iris metastasis as resistance mechanism to atezolizumab, carboplatin, and etoposide but responds to additional irinotecan and anlotinib in a small cell lung cancer patient

Small cell lung cancer (SCLC) is an aggressive malignancy associated with poor prognosis. Metastasis to sites outside the chest at the time of initial diagnosis, such as bone, brain, and liver metastasis have been found in most SCLC patients. Iris metastases from SCLC have rarely been previously reported, and often cause eye pain and blindness in patients. Here, we report a patient with SCLC who presented with iris metastasis in the right eye and metastasis in the left adrenal gland due to disease progression on first-line therapy, which subsequently caused pain and blindness in the right eye. The patient was treated with second-line irinotecan combined with anlotinib and atezolizumab and did not receive any local treatment in the right eye. After only one cycle of treatment, the iris metastases in the right eye were smaller than before, and the visual acuity in the right eye recovered. At the same time, her left adrenal metastases were also significantly smaller than before. Our case suggests that systemic therapy with effective treatment options can similarly improve iris metastases in patients.

DCZ19931, a novel multi-targeting kinase inhibitor, inhibits ocular neovascularization

Neovascularization is a prominent cause of irreversible blindness in a variety of ocular diseases. Current therapies for pathological neovascularization are concentrated on the suppression of vascular endothelial growth factors (VEGF). Despite the remarkable efficacy of anti-VEGF drugs, several problems still exist, including ocular complications and drug resistance. Thus, it is still required to design novel drugs for anti-angiogenic treatment. This study aimed to investigate the anti-angiogenic effects of a small molecule multi-target tyrosine kinase inhibitor, DCZ19931, on ocular neovascularization. The results showed that administration of DCZ19931 at the tested concentrations did not cause obvious cytotoxicity and tissue toxicity. DCZ19931 could reduce the size of choroidal neovascularization (CNV) lesions in laser-induced CNV model and suppress ocular neovascularization in oxygen-induced retinopathy (OIR) model. DCZ19931 could suppress VEGF-induced proliferation, migration, and tube formation ability of endothelial cells, exhibiting similar anti-angiogenic effects as Ranibizumab. DCZ19931 could reduce the levels of intercellular cell adhesion molecule-1 (ICAM-1) expression in vivo and in vitro. Network pharmacology prediction and western blots revealed that DCZ19931 exerted its anti-angiogenic effects through the inactivation of ERK1/2-MAPK signaling and p38-MAPK signaling. In conclusion, this study indicates that DCZ19931 is a promising drug for anti-angiogenic therapy for ocular diseases.

A hypothetical therapeutic effect of light peripheral panretinal photocoagulation in neovascular age-related macular degeneration

Background

Vascular endothelial growth factor (VEGF) is a significant modulator of ocular angiogenesis, including that of neovascular age-related macular degeneration (nAMD). Intravitreal injection of anti-VEGF is the benchmark treatment for most retinal vascular diseases, including nAMD, diabetic maculopathy, and macular edema secondary to retinal venous occlusion. Anti-VEGF treatment is a high-frequency, time-consuming, non-cost-effective therapy, especially in countries and regions with limited resources. This treatment is easily restricted, and in practice, maintaining long-term periodic care is challenging for patients.

Hypothesis

Light peripheral panretinal photocoagulation (PPRP) is applied in a mild form (barely visible mild light gray mark) anterior to the equator so as not to jeopardize the visual field. PPRP lessens the ischemia that causes neovascularization and decreases the metabolic demand in the peripheral retina. PPRP reduces serum angiopoietin-2 and VEGF levels in patients with type 2 diabetes mellitus with proliferative diabetic retinopathy. We propose using light PPRP to suppress VEGF secretion, aiming to attenuate the VEGF drive and halt choroidal neovascular growth in eyes with nAMD. Our regimen is based on two concepts: first, nAMD is a diffuse or generalized disease that affects the posterior segment; and second, PPRP is very effective in regressing diabetic retinopathy. PPRP has reportedly been successful in cases of macular edema (diabetic or following venous occlusion) resistant to VEGF antagonists. Light PPRP may be used as prophylaxis, adjunctive treatment, or monotherapy in nAMD when intravitreal injections of VEGF antagonists are not feasible.

Conclusions

The established light PPRP therapy could be promising as a one-time, cost-effective therapy or prophylaxis in patients with nAMD or at high risk. This proposed modality could be suitable for patients who have injection phobia or prefer a one-time affordable therapy to the long-term monthly visits to retinologists. Future trials are necessary to verify the safety and efficacy of this proposed treatment modality in selected patients with nAMD.

Suppression of Pathological Ocular Neovascularization by a Small Molecular Multi-Targeting Kinase Inhibitor, DCZ19903

Purpose

The administration of anti-vascular endothelial growth factor agents is the standard firs-line therapy for ocular vascular diseases, but some patients still have poor outcomes and drug resistance. This study investigated the role of DCZ19903, a small molecule multitarget kinase inhibitor, in ocular angiogenesis.

Methods

The toxicity of DCZ19903 was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assays, flow cytometry, Calcein-AM/PI staining, and terminal uridine nick-end labeling staining. Oxygen-induced retinopathy and laser-induced choroidal neovascularization models were adopted to assess the antiangiogenic effects of DCZ19903 by Isolectin B4 (GS-IB4) and hematoxylin-eosin staining. EdU assays, transwell migration assays, tube formation, and choroid sprouting assays were performed to determine the antiangiogenic effects of DCZ19903. The antiangiogenic mechanism of DCZ19903 was determined using network pharmacology approach and western blots.

Results

There was no obvious cytotoxicity or tissue toxicity after DCZ19903 treatment. DCZ19903 exerted the antiangiogenic effects in OIR model and choroidal neovascularization model. DCZ19903 inhibited the proliferation, tube formation, migration ability of endothelial cells, and choroidal explant sprouting. DCZ19903 plus ranibizumab achieved greater antiangiogenetic effects than DCZ19903 or ranibizumab alone. DCZ19903 exerted its antiangiogenic effects via affecting the activation of ERK1/2 and p38 signaling.

Conclusions

DCZ19903 is a promising drug for antiangiogenic treatment in ocular vascular diseases.

Translational Relevance

These findings suggest that DCZ19903 possesses great antiangiogenic potential for treating ocular vascular diseases.

Cytokine Expression in Staphylococcal and Streptococcal Endophthalmitis

<b><i>Background:</i></b> Endophthalmitis is an infection of ocular tissues, often with devastating outcomes for vision. Immunomodulation is an emerging avenue for therapeutic intervention in endophthalmitis, with the expression of cytokines central to potential mechanisms. This literature review with a systematic approach characterizes the cytokine expression in both animal and human staphylococcal and streptococcal endophthalmitis. <b><i>Method and Results:</i></b> Four online databases were searched for studies profiling cytokine levels in animal models or human populations with staphylococcal and/or streptococcal endophthalmitis. Of the 1,060 articles identified, 14 studies were included in this review comprising eight animal models and six human populations. Mouse, rat, and rabbit models of <i>Staphylococcus aureus</i>, <i>Staphylococcus epidermidis</i>, and <i>Streptococcus pneumoniae</i> endophthalmitis had elevated levels of IL-1β, IL-6, IFN-γ, TNF-α, and IL-8, with earlier peaks observed in <i>S</i>. <i>epidermidis</i> infection. Human endophthalmitis demonstrated significantly increased mediator levels compared to controls for a range of pro-inflammatory and anti-inflammatory cytokines, chemokines, and growth factors. Several associations were established between cytokine concentrations and both initial visual acuity and visual prognosis, with no consistent correlations across trials. <b><i>Conclusions:</i></b> It may be that virulence factors and the combinations of toll-like receptors activated influence the pathogen-specific visual outcomes observed in endophthalmitis. Furthermore, disease severity and potential therapeutic targets may be dependent on synergistic and compensatory cytokine pathways and the expression of anti-inflammatory mediators. Future research should aim to better characterize the roles of inflammatory mediators and solidify associations between pathogens, inflammation, and endophthalmitis outcomes. This has exciting implications for the prevention and treatment of endophthalmitis in clinical settings.

Biosimilar monoclonal antibodies in China: A patent review

Biosimilars play an important role in reducing the burden on patients and increasing the market competition. Biosimilar monoclonal antibodies are currently one of the hotspots of research and development in China with policies support. With the continuous improvement of policies, the enthusiasm for the research and development of biosimilars has increased year by year. The policy requirements in different periods have different degrees of impact on the patent applications of pharmaceutical companies. This review introduces the biosimilar monoclonal antibodies market status and approval process in China, analyzes the patents in this field, and helps pharmaceutical companies protect their intellectual property rights.

Systemic Complement Activation Profiles in Nonexudative Age-Related Macular Degeneration: A Systematic Review

Topic

To evaluate whether differences exist in systemic complement activation profiles in patients with early to intermediate nonexudative age-related macular degeneration (AMD) or geographic atrophy (GA) compared with control participants without AMD.

Clinical Relevance

Complement inhibition has emerged as a therapeutic strategy for GA, although clinical trials to date have yielded mixed results. Despite these efforts, no clear consensus exists regarding what portions of the complement pathway are dysregulated in AMD or when this dysregulation occurs relative to AMD stage. Although past studies have compared systemic complement activation profiles in patients with AMD versus in control participants without AMD, differences in AMD case definition and differing analytical approaches complicate their interpretation.

Methods

We performed a systematic review by identifying articles from database inception through October 11, 2020, that reported systemic complement activation profiles in patients with early or intermediate nonexudative AMD or GA versus control participants without AMD by searching PubMed, Google Scholar, and Embase. Risk of bias was assessed using a modified Newcastle-Ottawa score.

Results

The 8 reviewed studies included 2131 independent participants. Most studies report significantly higher systemic levels of products associated with complement activation and significantly lower systemic levels of products associated with complement inhibition in patients with early and advanced nonexudative AMD compared with control participants without AMD.

Discussion

Evidence suggests that systemic complement overactivation is a feature of early or intermediate and advanced nonexudative AMD. However, given significant heterogeneity, these findings are not conclusive and warrant further investigation.

Therapeutic Potential of Microvesicles in Cell Therapy and Regenerative Medicine of Ocular Diseases With an Especial Focus on Mesenchymal Stem Cells-Derived Microvesicles

These days, mesenchymal stem cells (MSCs), because of immunomodulatory and pro-angiogenic abilities, are known as inevitable factors in regenerative medicine and cell therapy in different diseases such as ocular disorder. Moreover, researchers have indicated that exosome possess an essential potential in the therapeutic application of ocular disease. MSC-derived exosome (MSC-DE) have been identified as efficient as MSCs for treatment of eye injuries due to their small size and rapid diffusion all over the eye. MSC-DEs easily transfer their ingredients such as miRNAs, proteins, and cytokines to the inner layer in the eye and increase the reconstruction of the injured area. Furthermore, MSC-DEs deliver their immunomodulatory cargos in inflamed sites and inhibit immune cell migration, resulting in improvement of autoimmune uveitis. Interestingly, therapeutic effects were shown only in animal models that received MSC-DE. In this review, we summarized the therapeutic potential of MSCs and MSC-DE in cell therapy and regenerative medicine of ocular diseases.

Self-assembled chitosan derived microparticles inhibit tumor angiogenesis and induce apoptosis in Ehrlich-ascites-tumor bearing mice

Self-assembled microparticles from chitosan (SAMC) was prepared by depolymerization induced by potassium persulfate. Particle size distribution data showed averaged around 5 μm size and SEM indicated the sequential formation of "RBC" shaped particles. Soluble SAMC consists of 'deacetylated' residues as revealed by ¹³C NMR. SAMC showed antitumor efficacy in human breast cancer cell lines through mitigation in cell proliferation, colony formation and cell migration. Anti-tumor and anti-angiogenic properties of SAMC was found in vivo Ehrlich ascites tumor (EAT) bearing mice model resulting in tumor growth inhibition (EAT control, 17.4 ml; SAMC treated, 6.8 ml) and improved survival potency (15 days). Moreover, the decrease in ascites VEGF secretion (EAT control, 1354 ng; SAMC treated, 351 ng) accompanied with reduction in neovessel formation. Apoptosis induction by SAMC was confirmed by DNA fragmentation, caspase activities and fluorescence staining methods respectively. SAMC may be a safe candidate for anti-tumor dietary supplement production in food industry.

Glycopeptide-nanotransforrs eyedrops with enhanced permeability and retention for preventing fundus neovascularization

Efficient and non-invasive drug delivery to the fundus has always been a medical difficulty. Here, a co-assembled glycopeptide nanotransforrs (GPNTs) named MRP@DOX as a drug delivery system is reported. The MRP@DOX co-assemble nanoparticles consisting of glycopeptide, cationic peptide, and doxorubicin (DOX). The nanoparticles are positively charged with the nano-size, which can be induced transformation by legumain cleavage. Once administrate to the eyes, MRP@DOX has a high penetration through the ocular surface to specifically targets M2 macrophages in the fundus. Then, the mannose receptor mediates phagocytosis and intracellular highly expressed legumain induces its nanofibrous transformation, which contributes to a 44.7% DOX retention in cells at 24 h than that of the non-transformed controls (MAP@DOX: 5.1%). The nanofiber transformation provides an inhibition of exocytosis, which explains the higher retention of the delivered drug. In the mouse OIR model, MRP@DOX completely restores the physiological angiogenesis and reduces pathological neovascularization. Pathological neovascularization branches and cell nuclei that break through the inner limiting membrane are reduced by 55% and 72%, respectively, which are 25% and 20% less than those in the non-transformed controls. In addition, MRP@DOX also has good histocompatibility, which provides a possible strategy for non-invasive treatment of fundus diseases in the future.

The Anti-Inflammatory Effect of Hydrogen Gas Inhalation and Its Influence on Laser-Induced Choroidal Neovascularization in a Mouse Model of Neovascular Age-Related Macular Degeneration

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.

A Systematic Review of Carotenoids in the Management of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) remains a leading cause of modifiable vision loss in older adults. Chronic oxidative injury and compromised antioxidant defenses represent essential drivers in the development of retinal neurodegeneration. Overwhelming free radical species formation results in mitochondrial dysfunction, as well as cellular and metabolic imbalance, which becomes exacerbated with increasing age. Thus, the depletion of systemic antioxidant capacity further proliferates oxidative stress in AMD-affected eyes, resulting in loss of photoreceptors, neuroinflammation, and ultimately atrophy within the retinal tissue. The aim of this systematic review is to examine the neuroprotective potential of the xanthophyll carotenoids lutein, zeaxanthin, and meso-zeaxanthin on retinal neurodegeneration for the purpose of adjunctive nutraceutical strategy in the management of AMD. A comprehensive literature review was performed to retrieve 55 eligible publications, using four database searches from PubMed, Embase, Cochrane Library, and the Web of Science. Epidemiology studies indicated an enhanced risk reduction against late AMD with greater dietary consumption of carotenoids, meanwhile greater concentrations in macular pigment demonstrated significant improvements in visual function among AMD patients. Collectively, evidence strongly suggests that carotenoid vitamin therapies offer remarkable synergic protection in the neurosensory retina, with the potential to serve as adjunctive nutraceutical therapy in the management of established AMD, albeit these benefits may vary among different stages of disease.

Age-Related Macular Degeneration

A 78-year-old woman presents with vision changes in the right eye for one week. Specifically, she describes central blurring in her vision and bending or waviness in straight lines. She also reports increasing difficulty reading print and often feels that there are blind spots in her vision. How would you diagnose and treat this patient?

Gene expression profile of the murine ischemic retina and its response to Aflibercept (VEGF-Trap)

Ischemic retinal dystrophies are leading causes of acquired vision loss. Although the dysregulated expression of the hypoxia-responsive VEGF-A is a major driver of ischemic retinopathies, implication of additional VEGF-family members in their pathogenesis has led to the development of multivalent anti-angiogenic tools. Designed as a decoy receptor for all ligands of VEGFR1 and VEGFR2, Aflibercept is a potent anti-angiogenic agent. Notwithstanding, the molecular mechanisms mediating Aflibercept's efficacy remain only partially understood. Here, we used the oxygen-induced retinopathy (OIR) mouse as a model system of pathological retinal vascularization to investigate the transcriptional response of the murine retina to hypoxia and of the OIR retina to Aflibercept. While OIR severely impaired transcriptional changes normally ensuing during retinal development, analysis of gene expression patterns hinted at alterations in leukocyte recruitment during the recovery phase of the OIR protocol. Moreover, the levels of Angiopoietin-2, a major player in the progression of diabetic retinopathy, were elevated in OIR tissues and consistently downregulated by Aflibercept. Notably, GO term, KEGG pathway enrichment, and expression dynamics analyses revealed that, beyond regulating angiogenic processes, Aflibercept also modulated inflammation and supported synaptic transmission. Altogether, our findings delineate novel mechanisms potentially underlying Aflibercept's efficacy against ischemic retinopathies.

MG53 inhibits angiogenesis through regulating focal adhesion kinase signalling

Mitsugumin 53 (MG53), which is expressed predominantly in striated muscle, has been demonstrated to be a myokine/cardiokine secreted from striated muscle under specific conditions. The important roles of MG53 in non-striated muscle tissues have also been examined in multiple disease models. However, no previous study has implicated MG53 in the control of endothelial cell function. In order to explore the effects of MG53 on endothelial cells, human umbilical vein endothelial cells (HUVECs) were stimulated with recombinant human MG53 (rhMG53). Then, rhMG53 uptake, focal adhesion kinase (FAK)/Src/Akt/ERK1/2 signalling pathway activation, cell migration and tube formation were determined in vitro. The efficacy of rhMG53 in regulating angiogenesis was also detected in postnatal mouse retinas. The results demonstrated that rhMG53 directly entered into endothelial cells in a cholesterol-dependent manner. The uptake of rhMG53 directly bound to FAK in endothelial cells, which resulted in a significant decrease in FAK phosphorylation at Y397. Accompanied by the dephosphorylation of FAK, rhMG53 uncoupled FAK-Src interaction and reduced the phosphorylation of Src at Y416. Consequently, the activation of FAK/Src downstream signalling pathways, such as Akt and ERK1/2, was also significantly inhibited by rhMG53. Furthermore, rhMG53 remarkably decreased HUVEC migration and tube formation in vitro and postnatal mouse retinal angiogenesis in vivo. Taken together, these data indicate that rhMG53 inhibits angiogenesis through regulating FAK/Src/Akt/ERK1/2 signalling pathways. This may provide a novel molecular mechanism for the impaired angiogenesis in ischaemic diseases.

Targeting choroidal vascular dysfunction via inhibition of circRNA-FoxO1 for prevention and management of myopic pathology

Myopia has become a global public health problem due to high prevalence. Although the etiological factors of myopia have been gradually recognized, the underlying mechanism remains largely elusive. Choroidal vascular dysfunction is recognized as a critical vision-threatening complication in myopia. Circular RNAs (circRNAs) are shown as the critical regulators in many biological processes and human diseases. In this study, we investigated the role of circRNAs in choroidal vascular dysfunction in myopia. The level of circFoxO1 was significantly upregulated in myopic choroid. circFoxO1 silencing suppressed choroidal endothelial cell viability, proliferation, migration, and tube formation in vitro and alleviated choroidal vascular dysfunction in vivo and ex vivo. circFoxO1 silencing retarded the progression of myopia as shown by reduced extracellular matrix remodeling and improved refractive error and axial elongation. Mechanistically, circFoxO1 acted as the sponge of miR-145 to sequester and inhibit miR-145 activity, thereby inducing VEGFA or ANGPT2 expression. miR-145 could mimic the effects of circFoxO1 silencing on choroidal endothelial phenotypes. Collectively, intervention of choroidal vascular dysfunction via regulating circFoxO1 level is a potential strategy for the prevention and management of myopia.

siRNA Therapeutics in Ocular Diseases

The field of RNAi therapeutics has quickly adapted to the treatment of ocular diseases. Although the eye provides a unique system for the delivery of siRNAs, its complex structure and composition fostered the development of novel strategies for efficient gene silencing in the target compartment. Moreover, anterior and posterior segments differ in their multiple drug barriers and clearance mechanisms. This chapter summarizes the recent achievements in terms of routes of administration, chemical modifications, and delivery systems for siRNAs that specifically apply to eye disorders. Methods employed for siRNA detection/quantitation in ocular tissues are also described, together with safety concerns that need to be addressed to fulfill regulatory requirements of new drug approval. Even though RNAi therapies for ocular diseases have not yet translated into patient care, we document herein the rising number of candidate drugs currently under preclinical or clinical development.

Future Perspectives of Therapeutic, Diagnostic and Prognostic Aptamers in Eye Pathological Angiogenesis

Aptamers are single-stranded DNA or RNA oligonucleotides that are currently used in clinical trials due to their selectivity and specificity to bind small molecules such as proteins, peptides, viral particles, vitamins, metal ions and even whole cells. Aptamers are highly specific to their targets, they are smaller than antibodies and fragment antibodies, they can be easily conjugated to multiple surfaces and ions and controllable post-production modifications can be performed. Aptamers have been therapeutically used for age-related macular degeneration, cancer, thrombosis and inflammatory diseases. The aim of this review is to highlight the therapeutic, diagnostic and prognostic possibilities associated with aptamers, focusing on eye pathological angiogenesis.

Assessment of a New Nanostructured Microemulsion System for Ocular Delivery of Sorafenib to Posterior Segment of the Eye

Eye drop formulations allowing topical treatment of retinal pathologies have long been sought as alternatives to intravitreal administration. This study aimed to assess whether a novel nanostructured microemulsions system (NaMESys) could be usefully employed to deliver sorafenib to the retina following topical instillation. NaMESys carrying 0.3% sorafenib (NaMESys-SOR) proved to be cytocompatible in vitro on rabbit corneal cells, and well-tolerated following b.i.d. ocular administration to rabbits during a 3-month study. In rats subject to retinal ischemia-reperfusion, NaMESys-SOR significantly inhibited retinal expression of tumor necrosis factor-alpha (TNFα, 20.7%) and inducible nitric oxide synthase (iNos, 87.3%) mRNAs in comparison to controls. Similarly, in streptozotocin-induced diabetic rats, NaMESys-SOR inhibited retinal expression of nuclear factor kappa B (NFκB), TNFα, insulin like growth factor 1 (IGF1), IGF1 receptor (IGF1R), vascular endothelial growth factor receptor 1 (VEGFR1) and 2 (VEGFR2) mRNAs by three-fold on average compared to controls. Furthermore, a reduction in TNFα, VEGFR1 and VEGFR2 protein expression was observed by western blot. Moreover, in mice subject to laser-induced choroidal neovascularization, NaMESys-SOR significantly inhibited neovascular lesions by 54%. In conclusion, NaMESys-SOR was shown to be a well-tolerated ophthalmic formulation able to deliver effective amounts of sorafenib to the retina, reducing proinflammatory and pro-angiogenic mediators in reliable models of proliferative retinopathies. These findings warrant further investigations on the full therapeutic potential of NaMESys-SOR eye drops, aiming to address unmet needs in the pharmacotherapy of retinal neovascular diseases.

Nanotechnology: revolutionizing the delivery of drugs to treat age-related macular degeneration

Introduction: Age-related macular degeneration (AMD) is a progressive retinal disease that degrades the eye's ability to grasp visual acuity. The antivascular endothelial growth factor (VEGF) therapies have made significant strides in improving the quality of life, and there is a continued opportunity to improve delivery, outcomes, and patient convenience and compliance. The treatments available could gain better clinical outcome from novel therapeutics through nanotechnology application.Areas covered: This review summarizes AMD biology and the pathophysiology of the disease along with the successes and limitations of available therapies. It further discusses the promising nanotechnology modalities that could become the cornerstone of future AMD research for improving delivery and reducing frequency of administration thus, enabling development of novel therapeutics.Expert opinion: The robust translation from preclinical work to clinical outcome for AMD remains an unmet need. Continuing to investigate in deeper understanding of biology and advancing high-quality targets into the clinic in combination with the application of advanced nanotechnology to design patient-centric offerings for both dry and wet AMD is needed. Because of the lack of regulatory precedence, and challenging manufacturing and supply chain need, the future of nano-enabled technologies is challenging but presents exciting treatment options for AMD.

Repurposing of Pirfenidone (Anti-Pulmonary Fibrosis Drug) for Treatment of Rheumatoid Arthritis

Clinical studies have shown that pirfenidone (PFD) effectively relieves joint pain in rheumatoid arthritis (RA) patients. However, the detailed mechanisms underlying the anti-RA effects of PFD have not been investigated. This study was undertaken to investigate the repurposing of PFD for the treatment of RA, and explore its anti-rheumatic mechanisms. A collagen-induced arthritis (CIA) rat model was used to observe joint pathological changes following PFD treatment. Based on bioinformatics to predict the mechanism of PFD anti-RA, using EA. hy926 and TNF-α-induced MH7A cells to establish in vitro model to explore its biological mechanism from the perspectives of synovial inflammation and angiogenesis. PFD significantly relieved pathological changes, including joint swelling, synovial hyperplasia, inflammatory cell infiltration and joint destruction. PFD was also associated with reduced expression of MMP-3 and VEGF in articular chondrocytes and synovial cells of CIA rats (p < 0.05). Using bioinformatic methods, we predicted that PFD inhibits cell inflammation and migration by interfering with the JAK2/STAT3 and Akt pathways. These results were verified using in vitro models. In particular, PFD effectively reduced the expression of pro-inflammatory, chondrogenic, and angiogenic cytokines, such as IL-1β, IL-6, IL-8, MMP-1/3/2/9 and VEGF (p < 0.05), in TNF-α-induced MH7A cells. In addition, PFD significantly reduced the production of MMP-2/9 and VEGF in EA. hy926 cells, thereby weakening migration and inhibiting angiogenesis (p < 0.05). These findings suggest that PFD may alleviate the pathological process in CIA rats, by inhibiting inflammation and angiogenesis through multiple pathways, and serve as a potential therapeutic drug for RA.

Viral-Vector-Delivered Anti-Angiogenic Therapies to the Eye

Pathological vessel growth harms vision and may finally lead to vision loss. Anti-angiogenic gene therapy with viral vectors for ocular neovascularization has shown great promise in preclinical studies. Most of the studies have been conducted with different adeno-associated serotype vectors. In addition, adeno- and lentivirus vectors have been used. Therapy has been targeted towards blocking vascular endothelial growth factors or other pro-angiogenic factors. Clinical trials of intraocular gene therapy for neovascularization have shown the treatment to be safe without severe adverse events or systemic effects. Nevertheless, clinical studies have not proceeded further than Phase 2 trials.

The Role of the ATP-Binding Cassette A1 (ABCA1) in Human Disease

Cholesterol homeostasis is essential in normal physiology of all cells. One of several proteins involved in cholesterol homeostasis is the ATP-binding cassette transporter A1 (ABCA1), a transmembrane protein widely expressed in many tissues. One of its main functions is the efflux of intracellular free cholesterol and phospholipids across the plasma membrane to combine with apolipoproteins, mainly apolipoprotein A-I (Apo A-I), forming nascent high-density lipoprotein-cholesterol (HDL-C) particles, the first step of reverse cholesterol transport (RCT). In addition, ABCA1 regulates cholesterol and phospholipid content in the plasma membrane affecting lipid rafts, microparticle (MP) formation and cell signaling. Thus, it is not surprising that impaired ABCA1 function and altered cholesterol homeostasis may affect many different organs and is involved in the pathophysiology of a broad array of diseases. This review describes evidence obtained from animal models, human studies and genetic variation explaining how ABCA1 is involved in dyslipidemia, coronary heart disease (CHD), type 2 diabetes (T2D), thrombosis, neurological disorders, age-related macular degeneration (AMD), glaucoma, viral infections and in cancer progression.

Pre-therapeutic Biomarkers for Ranibizumab Therapy among Type 2 Diabetic Patients with Diabetic Macular Edema

SIGNIFICANCE

A differential outcome in randomized controlled trials of anti-vascular endothelial growth factor (anti-VEGF) therapy, including ranibizumab, for diabetic macular edema is a major dilemma for planning, optimizing, and managing clinical usage. The variable outcome of the therapeutics necessitates the importance of finding a predictive biomarker for anti-VEGF therapy to improve subject selection.

PURPOSE

Our study correlates the baseline pro- and anti-VEGF isoforms and its three receptors (VEGFReceptor1, VEGFReceptor2, and VEGFReceptor3) for circulatory candidate protein molecules among diabetic patients with macular edema, with the clinical outcome of ranibizumab therapy.

METHODS

This study included 86 individuals who were anti-VEGF naive at the time of ascertainment but have completed the standardized therapy regimen of the clinic. Plasma proteins for pro- and anti-VEGF isoforms and its three receptors were determined in replicate by an enzyme-linked immunosorbent assay.

RESULTS

The study demonstrated that 56 (65.12%) individuals benefited from the therapy in terms of letter gain (Snellen chart). Baseline plasma soluble VEGF receptor 2 (sVEGFR-2) was significantly higher among responders (65.10 pg/mL; 95% confidence interval, 55.41 to 74.80 pg/mL) compared with nonresponders (46.38 pg/mL; 95% confidence interval, 38.69 to 54.07 pg/mL; PFDR = .03). Diffuse diabetic macular edema with proliferative diabetic retinopathy increases the risk of nonresponse to the therapy by 3.03-fold (PFDR = .04).

CONCLUSIONS

The present study postulates that diffuse diabetic macular edema with proliferative diabetic retinopathy and baseline circulatory soluble VEGF receptor 2 may be potential candidates as therapy-stratifying markers for ranibizumab treatment among patients with diabetic macular edema.

Immunological Aspects of Age-Related Macular Degeneration

Increasing evidence over the past two decades points to a pivotal role for immune mechanisms in age-related macular degeneration (AMD) pathobiology. In this chapter, we will explore immunological aspects of AMD, with a specific focus on how immune mechanisms modulate clinical phenotypes of disease and severity and how components of the immune system may serve as triggers for disease progression in both dry and neovascular AMD. We will briefly review the biology of the immune system, defining the role of immune mechanisms in chronic degenerative disease and differentiating from immune responses to acute injury or infection. We will explore current understanding of the roles of innate immunity (especially macrophages), antigen-specific immunity (T cells, B cells, and autoimmunity), immune amplifications systems, especially complement activity and the NLRP3 inflammasome, in the pathogenesis of both dry and neovascular AMD, reviewing data from pathology, experimental animal models, and clinical studies of AMD patients. We will also assess how interactions between the immune system and infectious pathogens could potentially modulate AMD pathobiology via alterations in in immune effector mechanisms. We will conclude by reviewing the paradigm of "response to injury," which provides a means to integrate various immunologic mechanisms along with nonimmune mechanisms of tissue injury and repair as a model to understand the pathobiology of AMD.

Reducing Treatment Burden in AMD

VEGF-A antagonists have revolutionized wet AMD treatment. Several challenges remain including high treatment burden requiring repeated intraocular injections for persistent disease. Brolucizumab directly inhibits VEGF-A function, providing visual outcomes comparable to aflibercept (an FDA-approved VEGF-A antagonist). Anatomic retinal outcomes including retinal fluid, a marker of disease activity, favored brolucizumab. To view this Bench to Bedisde, open or download the PDF.