The retinal pigment epithelium (RPE) degeneration and subsequent retinal atrophy are hallmarks of age-related macular degeneration (AMD). Amyloid-beta (Aβ), the primary component of amyloid plaques in Alzheimer’s disease (AD), is also present within drusen and is considered a critical factor contributing to RPE degeneration in AMD. Recent findings indicate that Aβ-induced inflammation plays a role in RPE degeneration. The aim of this study was to explore the molecular players and the precise mechanisms involved in this process, particularly the potential role of the absent in melanoma 2 (AIM2)-like receptors (ALRs) inflammasome. An animal model of Aβ1-40-induced RPE injury was established. Fundus photography, electrophysiology and hematoxylin-eosin staining were used to evaluate the morphological and functional RPE damage. Transcriptome sequencing was used to detect the differentially expressed genes between Aβ1-40 group and control group. The transcriptional and protein expression levels of AIM2 pathway and RIPK family members were detected. Adeno-associated virus vector 2/2 (AAV2/2)-shAIM2 was constructed to knockdown AIM2 expression in mice RPE cells. Aβ1-40-treated ARPE-19 cells and hRPE cells were employed to analyze the regulatory effects of RIPK family on mitochondrial DNA (mtDNA) release and AIM2 pathway activation. Aβ induces RPE damage through stimulation of AIM2 inflammasome and augmentation of caspase-1 and interleukin-1β (IL-1β). Knocking down AIM2 inhibits the release of inflammatory cytokines and alleviates the degeneration of the retina and RPE. Simultaneously, Aβ triggers the activation of RIPK1/RIPK3 kinases, as manifested by heightened protein expression and phosphorylation. Inhibiting RIPK1/RIPK3 phosphorylation dampens AIM2 inflammasome activity and curtails IL-1β secretion. Mechanistically, RIPK1/RIPK3 inhibition attenuates Aβ-induced Drp1(S616) hyperphosphorylation, consequently reducing mitochondrial fission and the efflux of mitochondrial DNA (mtDNA) into the cytosol. The diminished mtDNA release is responsible for attenuated AIM2 activation and subsequent inactivation of the stimulator of interferon genes (STING)/nuclear factor-kappa-B (NF-κB) signaling cascade. Our study is the first to validate AIM2’s contribution in Aβ-induced RPE pathology and underscore the significance of the RIPK1/RIPK3-induced mtDNA release in modulating inflammatory responses, shedding light on the underlying mechanisms and potential therapeutics of AMD.
Background: Faricimab stands as the inaugural and sole bispecific antibody approved by the US Food and Drug Administration (FDA) for intravitreal injection. Nonetheless, the efficacy and safety of intravitreal faricimab remained uncertain. Objectives: The purpose of this study was to evaluate faricimab. Methods: This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (CRD42023398320). Five databases (Pubmed, Embase, Web of science, Cochrane Library, ClinicalTrials gov) were searched. We calculated pooled standard mean difference or odds ratio with 95 % confident interval under a random-effect model or fixed-effect model. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was employed to ascertain the reliability of the analyses. Trial sequential analysis was performed to gauge the statistical reliability of the data in the cumulative meta-analysis. Results: 8 studies (3975 participants) were included. The use of faricimab was associated with central subfield thickness (CST) change, but no difference was found in other primary efficacy outcomes. Apart from that, a correlation was observed between the use of faricimab and the risk of vitreous floaters. Based on TSA, strong evidence indicates that compared to the control group, faricimab aided in reducing CST but increasing the risk of vitreous floaters. Conclusions: In this study, a correlation existed between the use of faricimab and a reduction in CST, indicating a superior therapeutic effect. Moreover, participants treated with faricimab demonstrated a higher risk of vitreous floaters. More randomized controlled trials are essential to further explore the efficacy and safety of faricimab.
Introduction: Neovascular age-related macular degeneration (NVAMD) is a leading cause of severe vision impairment in the elderly. Aging is one of the most pivotal underlying molecular mechanisms of NVAMD. Methods: In this study, we identified the potential aging-related genes involved in NVAMD. Considering that noncoding RNAs are vital regulators of NVAMD progression, we further explored and constructed an aging-originated circRNA-miRNA-mRNA network of NVAMD. Differential expression of 23 aging-associated genes was identified based on sequencing data and the Human Aging Genomic Resources tool at a threshold of p < 0.05, and log2|fold change| > 1. Results: We screened 12 microRNAs (miRNAs) using public datasets and miRNet database. A total of 13 circRNAs were subsequently mined using the starBase tool. Merging these 13 circRNAs, 12 miRNAs, and 15 genes together, we obtained 281 pairs of circRNA-miRNA and 30 pairs of miRNA-mRNA. Conclusion: We created an aging-related circRNA-miRNA-mRNA network, which could be a promising target for future AMD treatments.
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.
This study aims to evaluate the efficacy and safety of high-dose efdamrofusp alfa (IBI302, targeting VEGF and complement C3b/4b) with personalized dosing intervals in patients with neovascular age-related macular degeneration (nAMD). A multicenter, randomized, double-masked, active-controlled, noninferiority phase II trial. A total of 132 anti-VEGF naïve or previously treated participants with nAMD were enrolled. Eligible participants were randomized (1:1:1) to receive IBI302 6.4 mg, IBI302 8.0 mg, or aflibercept 2.0 mg. Efdamrofusp alfa groups were dosed every 8 weeks (Q8W) or every 12 weeks (Q12W), based on disease activity assessment at week 20, after 4 monthly injections. The aflibercept 2.0-mg group was dosed Q8W, after 3 monthly injections. The primary endpoint was the mean change in best-corrected visual acuity (BCVA) from baseline to week 40. The prespecified noninferiority margin was 4 letters. The least squares mean (standard error) changes in BCVA from baseline to week 40 were +10.5 (1.5) letters with IBI302 6.4 mg, +9.2 (1.5) letters with IBI302 8.0 mg, and +9.7 (1.5) letters with aflibercept 2.0 mg. The estimated differences were +0.8 (80% confidence interval: –1.9 to 3.6, noninferiority test: P = 0.0115) for IBI302 6.4 mg versus aflibercept 2.0 mg and –0.5 (–3.3 to 2.2, noninferiority test: P = 0.0123) for IBI302 8.0 mg versus aflibercept 2.0 mg. Over 80% of participants in IBI302 groups were dosed Q12W after week 20 and maintained their regimens until the end of study. Treatment-emergent adverse events (TEAEs) in the study eye were reported in 36.4% of participants receiving IBI302 6.4 mg, 37.8% receiving IBI302 8.0 mg, and 23.3% receiving aflibercept 2.0 mg. The most common ocular TEAE was conjunctival hemorrhage (9.1% for 6.4 mg and 11.1% for 8.0 mg) in both IBI302 groups, whereas cataract (7.0%) was the most frequent ocular TEAE in the aflibercept 2.0-mg group. Efdamrofusp alfa 6.4 and 8.0 mg dosed up to Q12W demonstrated noninferior visual gain to aflibercept 2.0 mg Q8W. Moreover, IBI302 groups were well tolerated. These findings suggested that high-dose IBI302 with extended dosing intervals could provide sustained visual benefits for patients with nAMD. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.