The Role of Inflammation in Age-Related Macular Degeneration: Updates and Possible Therapeutic Approaches

ROS-responsive drug delivery system with enhanced anti-angiogenic and anti-inflammatory properties for neovascular age-related macular degeneration therapy

Neovascular age-related macular degeneration (nAMD) has become the leading cause of vision loss in people over 60 years old. Anti-vascular endothelial growth factor (anti-VEGF), the current first-line drug for the treatment of nAMD, suffers from poor patient compliance and fundus fibrosis scar formation. In addition to VEGF, oxidative stress and inflammation also play key roles in the pathological process of choroidal neovascularization (CNV). Therefore, combinational therapeutics with anti-angiogenic, reactive oxygen species (ROS)-scavenging and anti-inflammatory functions will broaden therapeutic effects and reduce side effects. The Yes-associated protein-1 (YAP) has proven to inhibit angiogenesis, inflammation, and subretinal fibrosis in CNV. Herein, verteporfin (VP), the inhibitor of YAP, was encapsulated into a polydopamine modified mesoporous silica nanoparticle (PMSN-VP NPs) and then conjugated with PLGA-PEG-PBA decorated cerium oxide nanoparticles (PPCeO2 NPs) to develop an integrated nano-drug delivery system. The PMSN-VP@PPCeO2 NPs exhibited ROS-responsive degradation and VP release behaviors, and our in vitro data revealed that the PMSN-VP@PPCeO2 NPs downregulated angiogenic-related and fibrosis-related gene expressions in human umbilical vein endothelial cells (HUVECs) and further showed excellent anti-oxidative and anti-inflammatory capacities in BV2 cells. More importantly, the PMSN-VP@PPCeO2 NPs significantly suppressed vascular leakage and macrophage infiltration in the laser-induced CNV lesions of mice. Overall, our findings demonstrated that the PMSN-VP@PPCeO2 NPs provided an effective therapeutic strategy for nAMD.

Ref-1 is overexpressed in neovascular eye disease and targetable with a novel inhibitor

Reduction-oxidation factor-1 or apurinic/apyrimidinic endonuclease 1 (Ref-1/APE1) is a crucial redox-sensitive activator of transcription factors such as NF-κB, HIF-1α, STAT-3 and others. It could contribute to key features of ocular neovascularization including inflammation and angiogenesis; these underlie diseases like neovascular age-related macular degeneration (nAMD). We previously revealed a role for Ref-1 in the growth of ocular endothelial cells and in choroidal neovascularization (CNV). Here, we set out to further explore Ref-1 in neovascular eye disease. Ref-1 was highly expressed in human nAMD, murine laser-induced CNV and Vldlr-/- mouse subretinal neovascularization (SRN). Ref-1's interaction with a redox-specific small molecule inhibitor, APX2009, was shown by NMR and docking. This compound blocks crucial angiogenic features in multiple endothelial cell types. APX2009 also ameliorated murine laser-induced choroidal neovascularization (L-CNV) when delivered intravitreally. Moreover, systemic APX2009 reduced murine SRN and downregulated the expression of Ref-1 redox regulated HIF-1α target carbonic anhydrase 9 (CA9) in the Vldlr-/- mouse model. Our data validate the redox function of Ref-1 as a critical regulator of ocular angiogenesis, indicating that inhibition of Ref-1 holds therapeutic potential for treating nAMD.

The impact of NF-κB on inflammatory and angiogenic processes in age-related macular degeneration

Age-related macular degeneration (AMD) is a prominent cause of vision loss, characterized by two different types, dry (atrophic) and wet (neovascular). Dry AMD is distinguished by the progressive deterioration of retinal cells, which ultimately causes a decline in vision. In contrast, wet AMD is defined by the abnormal development of blood vessels underneath the retina, leading to a sudden and severe vision impairment. The course of AMD is primarily driven by chronic inflammation and pathological angiogenesis, in which the NF-κB signaling pathway plays a crucial role. The activation of NF-κB results in the generation of pro-inflammatory cytokines, chemokines, and angiogenic factors like VEGF, which contribute to inflammation and the formation of new blood vessels in AMD. This review analyzes the intricate relationship between NF-κB signaling, inflammation, and angiogenesis in AMD and assesses the possibility of using NF-κB as a target for therapy. The evaluation involves a comprehensive examination of preclinical and clinical evidence that substantiates the effectiveness of NF-κB inhibitors in treating AMD by diminishing inflammation and pathological angiogenesis.

Janus Kinase Inhibitor Therapy and Risk of Age-Related Macular Degeneration in Autoimmune Disease

Importance

The involvement of chronic inflammation in the pathogenesis of age-related macular degeneration (AMD) opens therapeutic possibilities to AMD management.

Objective

To determine whether Janus kinase inhibitors (JAKis) are associated with a reduced risk of AMD development in patients with autoimmune diseases.

Design, Setting, and Participants

This retrospective observational cohort study used administrative claims data from Merative MarketScan research databases (Commercial and Medicare Supplemental) and Optum Clinformatics Data Mart databases between January 1, 2010, and January 31, 2022. Patients with autoimmune diseases satisfying study eligibility criteria and who received JAKi treatment (9126 in MarketScan and 5667 in Optum) were propensity score matched (1:1) to identical numbers of study-eligible patients who received non-JAKi-based immunotherapy.

Exposure

Treatment duration of 6 months or longer.

Main Outcomes and Measures

Incidence rates of AMD (exudative and nonexudative) over the first 6 to 18 months of treatment were determined, and bayesian Poisson regression models were used to estimate incidence rate ratios, 95% CIs, and posterior probabilities of AMD.

Results

After matching, female sex represented the majority of the patient population in both MarketScan and Optum (14 019/18 252 [76.6%] and 8563/3364 [75.2%], respectively in the JAKi patient population). More than 60% of the patient population was older than 55 years of age in both cohorts. Over the specified treatment period, a 49% relative reduction in incidence of AMD was observed among patients who received JAKi therapy (10/9126 events; adjusted incidence rate ratio [AIRR], 0.51; 95% CI, 0.19-0.90) vs those who received non-JAKi therapy (43/9126 events; AIRR, 1 [reference]) in MarketScan, and a 73% relative reduction in incidence of AMD was observed among patients who received JAKi therapy (3/5667 events; AIRR, 0.27; 95% CI, 0.03-0.74) vs those who received non-JAKi therapy (21/5667 events; AIRR, 1 [reference]) in Optum. The absolute percentage reductions were 0.36% (MarketScan) and 0.32% (Optum), favoring patients who received JAKi therapy. Posterior probabilities of the adjusted risk being less than unity were 97.6% (MarketScan) and 98.9% (Optum) for those who received JAKi therapy vs those who received non-JAKi therapy in MarketScan and Optum, respectively.

Conclusions and Relevance

JAKi use may be associated with a reduced risk of incident AMD in US adults with major autoimmune diseases. The absolute percentage reduction is consistent with a potential role for JAKi in this population. Future studies with long-term follow-up are recommended to investigate the association between JAKi use and incident AMD in other disease indications. Investigation into the role of systemic inflammation and JAK-signal transducers and activators of transcription signaling in AMD may improve understanding of the pathophysiology of AMD and lead to new treatment options.

Optical coherence tomography-derived texture-based radiomics features identify eyes with intraocular inflammation in the HAWK clinical trial

Background and objective

Intravitreal injection of anti-VEGF agents is the first-line treatment for patients with neovascular-age related macular degeneration (nAMD). One unique serious adverse event that may be associated with these agents is intraocular inflammation (IOI). The main purpose of this analysis was to evaluate the potential presence of texture-based radiomics features characterizing heterogeneity within the vitreous compartment of spectral domain optical coherence tomography (SD-OCT) images that may precede or develop in association with IOI and might serve as OCT biomarkers for IOI.

Methods

This is a post-hoc analysis of a subset of cases (N = 67) involving IOI, endophthalmitis, and/or retinal vascular occlusion in the phase 3 HAWK trial. These were investigator determined diagnoses that were also confirmed by the safety review committee. Intraocular inflammation was any signs of inflammation within the eye, endophthalmitis was inflammation associated with presumed infection, and retinal vascular occlusions consisted of intraocular inflammation with concurrent vascular occlusions/vasculitis. Out of 67 eyes, 34 belonged to the Safety group with an IOI event and 33 were propensity-matched Controls. A total of 481 texture-based radiomics features were extracted from the vitreous compartment of the SD-OCT scans at pre-IOI time point (i.e., much earlier than the actual event). Most discriminating five features, selected by the Wilcoxon Rank Sum feature selection were evaluated using Random Forest (RF) classifier on the training set (S t r , N = 47) to differentiate between the two patient groups. Classifier performance was subsequently validated on the independent test set (S t , N = 20). Additionally, the classifier performance in discriminating the Control and Safety group was also validated onS t at the IOI event timepoint.

Results

The RF classifier yielded area under the Receiver Operating Characteristics curve (AUC) of 0.76 and 0.81 onS t using texture-based radiomics features at pre-IOI and event time-point, respectively.

Conclusions

In this analysis, the presence of a pre-IOI safety signal was detected in the form of textural heterogeneity within the vitreous compartment even prior to the actual event being identified by the investigator. This finding may help the clinicians to assess for underlying posterior inflammation.

Risk and protection of different rare protein-coding variants of complement component C4A in age-related macular degeneration

Introduction: Age-related macular degeneration (AMD) is the leading cause of central vision loss in the elderly. One-third of the genetic contribution to this disease remains unexplained. Methods: We analyzed targeted sequencing data from two independent cohorts (4,245 cases, 1,668 controls) which included genomic regions of known AMD loci in 49 genes. Results: At a false discovery rate of <0.01, we identified 11 low-frequency AMD variants (minor allele frequency <0.05). Two of those variants were present in the complement C4A gene, including the replacement of the residues that contribute to the Rodgers-1/Chido-1 blood group antigens: [VDLL1207-1210ADLR (V1207A)] with discovery odds ratio (OR) = 1.7 (p = 3.2 × 10-5) which was replicated in the UK Biobank dataset (3,294 cases, 200,086 controls, OR = 1.52, p = 0.037). A novel variant associated with reduced risk for AMD in our discovery cohort was P1120T, one of the four C4A-isotypic residues. Gene-based tests yielded aggregate effects of nonsynonymous variants in 10 genes including C4A, which were associated with increased risk of AMD. In human eye tissues, immunostaining demonstrated C4A protein accumulation in and around endothelial cells of retinal and choroidal vasculature, and total C4 in soft drusen. Conclusion: Our results indicate that C4A protein in the complement activation pathways may play a role in the pathogenesis of AMD.

Vascular Cell Adhesion Molecule-1 (VCAM-1) contributes to macular fibrosis in neovascular age-related macular degeneration through modulating macrophage functions

BACKGROUND

Neovascular age-related macular degeneration (nAMD) is a major cause of blindness in the elderly. The disease is due to the growth of abnormal blood vessels into the macula, leading to the loss of central vision. Intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors (e.g., anti-VEGF) is the standard of care for nAMD. However, nearly 50% of patients do not respond or respond poorly to the therapy. More importantly, up to 70% of nAMD patients develop macular fibrosis after 10 years of anti-VEGF therapy. The underlying mechanism of nAMD-mediated macular fibrosis is unknown although inflammation is known to play an important role in the development of abnormal macular blood vessels and its progression to fibro-vascular membrane. In this study, we measured the intraocular levels of adhesion molecule VCAM-1, ICAM-1, CD44, CD62L, and CD62P in nAMD patients with and without macular fibrosis and investigated the link between the levels of adhesion molecule and clinical features (e.g., visual improvement, retinal thickness, etc.). We further investigated the effect of VCAM-1 in macrophage function in vitro and the development of subretinal fibrosis in vivo using a two-stage laser-induced protocol.

RESULTS

The aqueous levels of ICAM-1, VCAM-1, CD44, and CD62L were significantly higher in nAMD patients compared to cataract controls. The aqueous level of VCAM-1 (but not other adhesion molecules) was significantly higher in patients with macular fibrosis than those without and the level correlated positively with the retinal thickness. VCAM-1 was highly expressed at the lesion site in the mouse model of subretinal fibrosis. Blocking VCAM-1 or its receptor VLA-4 significantly prevented macrophage infiltration and reduced subretinal fibrosis in vivo. VCAM-1 induced macrophage migration and upregulated the expression of Arg-1, Mmp12 and Il6 but down-regulated the expression of iNOS and Il1b in macrophages.

CONCLUSIONS

VCAM-1 may contribute to the development of macular fibrosis in nAMD patients by modulating macrophage functions, including migration and profibrotic polarization.