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Seddon JM, De D, Rosner B. The role of nutritional factors in transitioning between early, mid, and late stages of age-related macular degeneration: prospective longitudinal analysis. Am J Clin Nutr 2024:S0002-9165(24)00711-1. [PMID: 39181206 DOI: 10.1016/j.ajcnut.2024.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 08/15/2024] [Accepted: 08/19/2024] [Indexed: 08/27/2024] Open
Abstract
BACKGROUND Transitions between different stages of age-related macular degeneration (AMD) are not completely captured by traditional survival models with an end point of advanced AMD. OBJECTIVES This study aimed to explore the transitions from early and intermediate AMD to higher nonadvanced and advanced stages and determine the contributions of nutritional factors to these outcomes. METHODS Eyes with early or intermediate AMD at baseline, classified according to the Age-Related Eye Disease Study severity score, were included in this prospective longitudinal analysis. Foods and the biologically active nutrients associated with AMD [green leafy vegetables, fish, lutein/zeaxanthin (LZ), and ω-3 (n-3) fatty acids] were determined by a baseline food frequency questionnaire. Progression was defined as eyes transitioning to higher severity groups including nonadvanced and advanced stages over 5 y, confirmed at 2 consecutive visits. Cox proportional hazards models for foods and nutrients were analyzed adjusting for demographics, lifestyle, baseline macular status, a family history of AMD, caloric intake, and genetic risk. RESULTS Among 2697 eyes, 616 (23%) progressed to higher severity groups. In the food group model, higher intake of green leafy vegetables reduced incidence of transitions {hazard ratio [HR] (≥2.7 servings/wk compared with none): 0.75; 95% confidence interval [CI]: 0.59, 0.96; P = 0.02}. Higher fish intake was also protective [HR (greater than two 4-ounce servings/wk compared with <2): 0.79; 95% CI: 0.65, 0.95; P = 0.01]. In the nutrient model, LZ intake was protective [HR (≥2 mg/d compared with <2): 0.76; 95% CI: 0.60, 0.96; P = 0.02]. Higher intake of ω-3 fatty acids also tended to be beneficial [HR (≥0.7 g/wk compared with <0.7): 0.85; 95% CI: 0.71, 1.01; P = 0.06]. CONCLUSIONS Increased consumption of green leafy vegetables, LZ, and fish nutritionally rich in ω-3 fatty acids during the initial stages of AMD may reduce rates of progression to higher severity of this debilitating disease. This trial was registered at clinicaltrials.gov as NCT00594672.
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Affiliation(s)
- Johanna M Seddon
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Chan Medical School, Worcester, MA, United States.
| | - Dikha De
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Bernard Rosner
- Channing Division of Network Medicine, Department of Medicine, Harvard Medical School, Boston, MA, United States
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Hallam TM, Andreadi A, Sharp SJ, Brocklebank V, Gardenal E, Dreismann A, Lotery AJ, Marchbank KJ, Harris CL, Jones AV, Kavanagh D. Comprehensive functional characterization of complement factor I rare variant genotypes identified in the SCOPE geographic atrophy cohort. J Biol Chem 2024; 300:107452. [PMID: 38852887 PMCID: PMC11277764 DOI: 10.1016/j.jbc.2024.107452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/11/2024] Open
Abstract
Rare variants (RVs) in the gene encoding the regulatory enzyme complement factor I (CFI; FI) that reduce protein function or levels increase age-related macular degeneration risk. A total of 3357 subjects underwent screening in the SCOPE natural history study for geographic atrophy secondary to age-related macular degeneration, including CFI sequencing and serum FI measurement. Eleven CFI RV genotypes that were challenging to categorize as type I (low serum level) or type II (normal serum level, reduced enzymatic function) were characterized in the context of pure FI protein in C3b and C4b fluid phase cleavage assays and a novel bead-based functional assay (BBFA) of C3b cleavage. Four variants predicted or previously characterized as benign were analyzed by BBFA for comparison. In all, three variants (W51S, C67R, and I370T) resulted in low expression. Furthermore, four variants (P64L, R339Q, G527V, and P528T) were identified as being highly deleterious with IC50s for C3b breakdown >1 log increased versus the WT protein, while two variants (K476E and R474Q) were ∼1 log reduced in function. Meanwhile, six variants (P50A, T203I, K441R, E548Q, P553S, and S570T) had IC50s similar to WT. Odds ratios and BBFA IC50s were positively correlated (r = 0.76, p < 0.01), while odds ratios versus combined annotation dependent depletion (CADD) scores were not (r = 0.43, p = 0.16). Overall, 15 CFI RVs were functionally characterized which may aid future patient stratification for complement-targeted therapies. Pure protein in vitro analysis remains the gold standard for determining the functional consequence of CFI RVs.
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Affiliation(s)
- Thomas M Hallam
- Gyroscope Therapeutics Limited, A Novartis Company, London, UK.
| | - Anneliza Andreadi
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK; National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Scott J Sharp
- Gyroscope Therapeutics Limited, A Novartis Company, London, UK
| | - Vicky Brocklebank
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK; National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | | | - Anna Dreismann
- Gyroscope Therapeutics Limited, A Novartis Company, London, UK
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University Hospital Southampton, University of Southampton, Southampton, UK
| | - Kevin J Marchbank
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK; National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Claire L Harris
- Gyroscope Therapeutics Limited, A Novartis Company, London, UK; Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Amy V Jones
- Gyroscope Therapeutics Limited, A Novartis Company, London, UK
| | - David Kavanagh
- Complement Therapeutics Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK; National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK; Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK.
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Seddon JM, De D, Rosner B. Family History of Age-Related Macular Degeneration and Genetics Predict Progression to Advanced Age-Related Macular Degeneration Adjusting for Macular Status, Demographic, and Lifestyle Factors. Am J Ophthalmol 2023; 255:74-86. [PMID: 37437830 DOI: 10.1016/j.ajo.2023.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 06/16/2023] [Accepted: 06/16/2023] [Indexed: 07/14/2023]
Abstract
PURPOSE To determine if a family history of age-related macular degeneration (AMD) and genetic variants identify eyes at higher risk for progression to advanced AMD (AAMD), after controlling for baseline demographics, behavioral factors, and macular status. DESIGN Prospective, longitudinal cohort study. METHODS Eyes were classified using the Age-Related Eye Disease Study severity scale. Non-genetic and genetic predictors for progression to AAMD, geographic atrophy, and neovascular disease were evaluated. Cox proportional hazards models using the eye as the unit of analysis were used to calculate hazard ratios (HRs), accounting for correlated data. Discrimination between progressing and non-progressing eyes was assessed using C-statistics and net reclassification improvement (NRI). RESULTS Among 4910 eyes, 863 progressed to AAMD over 12 years. Baseline AMD severity scale and status of the fellow eye were important predictors; genes provided additional discrimination. A family history of AMD also independently predicted progression after accounting for genetic and other covariates: 1 family member versus none (HR 1.21 [95% confidence interval {CI} 1.02-1.43]; P = 0.03); ≥2 family members versus none (HR 1.55 [95% CI 1.26-1.90]; P < 0.001). A composite risk score calculated using β estimates of both non-genetic and significant genetic factors predicted progression to AAMD (HR 5.57; 90th vs 10th percentile; area under the receiver operating characteristic curve [AUC] = 0.92), providing superior fit compared with other models, including one with only ocular variables (NRI = 0.34; P < 0.001; AUC = 0.87, ΔAUC 0.05 ± 0.005; P < 0.001). CONCLUSION Genetic variants and family history provided additional discrimination for predicting progression to AAMD, after accounting for baseline macular status and other covariates.
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Affiliation(s)
- Johanna M Seddon
- From the Department of Ophthalmology and Visual Sciences (J.M.S., D.D.), University of Massachusetts Chan Medical School, Worcester, Massachusetts.
| | - Dikha De
- From the Department of Ophthalmology and Visual Sciences (J.M.S., D.D.), University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Bernard Rosner
- Department of Medicine (B.R.), Channing Division of Network Medicine, Harvard Medical School, Boston, Massachusetts, USA
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Shughoury A, Sevgi DD, Ciulla TA. The complement system: a novel therapeutic target for age-related macular degeneration. Expert Opin Pharmacother 2023; 24:1887-1899. [PMID: 37691588 DOI: 10.1080/14656566.2023.2257604] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/31/2023] [Accepted: 09/07/2023] [Indexed: 09/12/2023]
Abstract
INTRODUCTION With the recent FDA approvals of pegcetacoplan (SYFOVRE, Apellis Pharmaceuticals) and avacincaptad pegol (IZERVAY, Astellas Pharmaceuticals), modulation of the complement system has emerged as a promising therapeutic approach for slowing progression of geographic atrophy (GA) in AMD. AREAS COVERED This article reviews the current understanding of the complement system, its role in AMD, and the various complement-targeting therapies in development for the treatment of GA, including monoclonal antibodies, aptamers, protein analogs, and gene therapies. Approved and investigational agents have largely focused on interfering with the activity of complement components 3 and 5, owing to their central roles in the classical, lectin, and alternative complement pathways. Other investigational therapies have targeted formation of membrane attack complex (a terminal step in the complement cascade which leads to cell lysis), complement factors H and I (which serve regulatory functions in the alternative pathway), complement factors B and D (within the alternative pathway), and complement component 1 (within the classical pathway). Clinical trials investigating these agents are summarized, and the potential benefits and limitations of these therapies are discussed. EXPERT OPINION Targeting the complement system is a promising therapeutic approach for slowing the progression of GA in AMD, potentially improving visual outcomes. However, increased risk of exudative conversion must be considered, and further research is required to identify clinical criteria and best practices for initiating complement inhibitor therapy for GA.
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Affiliation(s)
- Aumer Shughoury
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Duriye D Sevgi
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Thomas A Ciulla
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
- Clearside Biomedical, Inc, Alpharetta, GA, USA
- Midwest Eye Institute, Carmel, IN, USA
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Grunin M, de Jong S, Palmer EL, Jin B, Rinker D, Moth C, Capra A, Haines JL, Bush WS, den Hollander AI. Spatial Distribution of Missense Variants within Complement Proteins Associates with Age Related Macular Degeneration. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.08.28.23294686. [PMID: 37693462 PMCID: PMC10491280 DOI: 10.1101/2023.08.28.23294686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Purpose Genetic variants in complement genes are associated with age-related macular degeneration (AMD). However, many rare variants have been identified in these genes, but have an unknown significance, and their impact on protein function and structure is still unknown. We set out to address this issue by evaluating the spatial placement and impact on protein structureof these variants by developing an analytical pipeline and applying it to the International AMD Genomics Consortium (IAMDGC) dataset (16,144 AMD cases, 17,832 controls). Methods The IAMDGC dataset was imputed using the Haplotype Reference Consortium (HRC), leading to an improvement of over 30% more imputed variants, over the original 1000 Genomes imputation. Variants were extracted for the CFH , CFI , CFB , C9 , and C3 genes, and filtered for missense variants in solved protein structures. We evaluated these variants as to their placement in the three-dimensional structure of the protein (i.e. spatial proximity in the protein), as well as AMD association. We applied several pipelines to a) calculate spatial proximity to known AMD variants versus gnomAD variants, b) assess a variant's likelihood of causing protein destabilization via calculation of predicted free energy change (ddG) using Rosetta, and c) whole gene-based testing to test for statistical associations. Gene-based testing using seqMeta was performed using a) all variants b) variants near known AMD variants or c) with a ddG >|2|. Further, we applied a structural kernel adaptation of SKAT testing (POKEMON) to confirm the association of spatial distributions of missense variants to AMD. Finally, we used logistic regression on known AMD variants in CFI to identify variants leading to >50% reduction in protein expression from known AMD patient carriers of CFI variants compared to wild type (as determined by in vitro experiments) to determine the pipeline's robustness in identifying AMD-relevant variants. These results were compared to functional impact scores, ie CADD values > 10, which indicate if a variant may have a large functional impact genomewide, to determine if our metrics have better discriminative power than existing variant assessment methods. Once our pipeline had been validated, we then performed a priori selection of variants using this pipeline methodology, and tested AMD patient cell lines that carried those selected variants from the EUGENDA cohort (n=34). We investigated complement pathway protein expression in vitro , looking at multiple components of the complement factor pathway in patient carriers of bioinformatically identified variants. Results Multiple variants were found with a ddG>|2| in each complement gene investigated. Gene-based tests using known and novel missense variants identified significant associations of the C3 , C9 , CFB , and CFH genes with AMD risk after controlling for age and sex (P=3.22×10 -5 ;7.58×10 -6 ;2.1×10 -3 ;1.2×10 -31 ). ddG filtering and SKAT-O tests indicate that missense variants that are predicted to destabilize the protein, in both CFI and CFH, are associated with AMD (P=CFH:0.05, CFI:0.01, threshold of 0.05 significance). Our structural kernel approach identified spatial associations for AMD risk within the protein structures for C3, C9, CFB, CFH, and CFI at a nominal p-value of 0.05. Both ddG and CADD scores were predictive of reduced CFI protein expression, with ROC curve analyses indicating ddG is a better predictor (AUCs of 0.76 and 0.69, respectively). A priori in vitro analysis of variants in all complement factor genes indicated that several variants identified via bioinformatics programs PathProx/POKEMON in our pipeline via in vitro experiments caused significant change in complement protein expression (P=0.04) in actual patient carriers of those variants, via ELISA testing of proteins in the complement factor pathway, and were previously unknown to contribute to AMD pathogenesis. Conclusion We demonstrate for the first time that missense variants in complement genes cluster together spatially and are associated with AMD case/control status. Using this method, we can identify CFI and CFH variants of previously unknown significance that are predicted to destabilize the proteins. These variants, both in and outside spatial clusters, can predict in-vitro tested CFI protein expression changes, and we hypothesize the same is true for CFH . A priori identification of variants that impact gene expression allow for classification for previously classified as VUS. Further investigation is needed to validate the models for additional variants and to be applied to all AMD-associated genes.
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Busch C, Rau S, Sekulic A, Perie L, Huber C, Gehrke M, Joussen AM, Zipfel PF, Wildner G, Skerka C, Strauß O. Increased plasma level of terminal complement complex in AMD patients: potential functional consequences for RPE cells. Front Immunol 2023; 14:1200725. [PMID: 37359546 PMCID: PMC10287163 DOI: 10.3389/fimmu.2023.1200725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/23/2023] [Indexed: 06/28/2023] Open
Abstract
Purpose Polymorphisms in complement genes are risk-associated for age-related macular degeneration (AMD). Functional analysis revealed a common deficiency to control the alternative complement pathway by risk-associated gene polymorphisms. Thus, we investigated the levels of terminal complement complex (TCC) in the plasma of wet AMD patients with defined genotypes and the impact of the complement activation of their plasma on second-messenger signaling, gene expression, and cytokine/chemokine secretion in retinal pigment epithelium (RPE) cells. Design Collection of plasma from patients with wet AMD (n = 87: 62% female and 38% male; median age 77 years) and controls (n = 86: 39% female and 61% male; median age 58 years), grouped for risk factor smoking and genetic risk alleles CFH 402HH and ARMS2 rs3750846, determination of TCC levels in the plasma, in vitro analysis on RPE function during exposure to patients' or control plasma as a complement source. Methods Genotyping, measurement of TCC concentrations, ARPE-19 cell culture, Ca2+ imaging, gene expression by qPCR, secretion by multiplex bead analysis of cell culture supernatants. Main outcome measures TCC concentration in plasma, intracellular free Ca2+, relative mRNA levels, cytokine secretion. Results TCC levels in the plasma of AMD patients were five times higher than in non-AMD controls but did not differ in plasma from carriers of the two risk alleles. Complement-evoked Ca2+ elevations in RPE cells differed between patients and controls with a significant correlation between TCC levels and peak amplitudes. Comparing the Ca2+ signals, only between the plasma of smokers and non-smokers, as well as heterozygous (CFH 402YH) and CFH 402HH patients, revealed differences in the late phase. Pre-stimulation with complement patients' plasma led to sensitization for complement reactions by RPE cells. Gene expression for surface molecules protective against TCC and pro-inflammatory cytokines increased after exposure to patients' plasma. Patients' plasma stimulated the secretion of pro-inflammatory cytokines in the RPE. Conclusion TCC levels were higher in AMD patients but did not depend on genetic risk factors. The Ca2+ responses to patients' plasma as second-messenger represent a shift of RPE cells to a pro-inflammatory phenotype and protection against TCC. We conclude a substantial role of high TCC plasma levels in AMD pathology.
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Affiliation(s)
- Catharina Busch
- Department of Ophthalmology, University Hospital Leipzig, Leipzig, Germany
| | - Saskia Rau
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Andjela Sekulic
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Luce Perie
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Christian Huber
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Miranda Gehrke
- Section of Immunobiology, Department of Ophthalmology, University Hospital, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Antonia M. Joussen
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
- Institute of Microbiology, Friedrich-Schiller-University, Jena, Germany
| | - Gerhild Wildner
- Section of Immunobiology, Department of Ophthalmology, University Hospital, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
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Seddon JM, Rosner B, De D, Huan T, Java A, Atkinson J. Rare Dysfunctional Complement Factor I Genetic Variants and Progression to Advanced Age-Related Macular Degeneration. OPHTHALMOLOGY SCIENCE 2023; 3:100265. [PMID: 36909148 PMCID: PMC9993025 DOI: 10.1016/j.xops.2022.100265] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/02/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022]
Abstract
Purpose To evaluate associations between rare dysfunctional complement factor I (CFI) genetic variant status and progression to advanced age-related macular degeneration (AAMD), geographic atrophy (GA), and neovascular disease (NV). Design Prospective, longitudinal study. Participants Patients aged 55 to 80 years at baseline identifying as White with non-AAMD in 1 or both eyes at baseline were included. Follow-up grades were assigned as early, intermediate, or AAMD (GA or NV). CFI variants were categorized using genotyping and sequencing platforms. Methods Analyses were performed using the Seddon Longitudinal Cohort Study (N = 2116 subjects, 3901 eyes, and mean follow-up of 8.3 years) and the Age-Related Eye Disease Study (N = 2837 subjects, 5200 eyes, and mean follow-up of 9.2 years). CFI rare variants associated with low serum factor I (FI) protein levels and decreased FI function (type 1), other AMD genetic variants, and demographic, behavioral, and ocular factors were evaluated. Generalized estimating equations methods were used to assess the association between CFI rare variants and progression, independent of other genetic variants and covariates. Main Outcome Measures Progression to AAMD, GA, or NV. Results In the prospective cohort of 4953 subjects (9101 eyes with non-AAMD at baseline), 1% were type 1 rare CFI carriers. Over 12 years, progression to AAMD was 44% for carriers and 20% for noncarriers (P < 0.001), 30% of carriers versus 10% of noncarriers progressed to GA (P < 0.001), and 18% of carriers compared with 11% of noncarriers progressed to NV (P = 0.049). CFI carriers were more likely to have a family history of AMD (P for trend = 0.035) and a higher baseline AMD grade (P < 0.001). After adjusting for all covariates, CFI carrier status was associated with progression to GA (odds ratio [OR] = 1.91; 95% confidence interval [CI] = 1.03, 3.52) but not NV (OR = 0.96). Higher body mass index was associated with progression among CFI carriers (body mass index ≥ 25 vs. < 25; OR = 5.8; 95% CI 1.5, 22.3) but not for noncarriers (OR = 1.1; 95% CI = 0.9, 1.3), with P_interaction = 0.011. Conclusions Results suggest that carriers of rare dysfunctional type 1 CFI variants are at higher risk for progression to AAMD with GA. Financial Disclosures Proprietary or commercial disclosure may be found after the references.
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Key Words
- AAMD, advanced age-related macular degeneration
- AMD, age-related macular degeneration
- AREDS, Age-Related Eye Disease Study
- Advanced age-related macular degeneration
- BMI, body mass index
- C3, complementcomponent 3
- C9, complementcomponent 9
- CD35, cluster of differentiation 35 (also called complement receptor 1)
- CD46, cluster of differentiation 46 (also called membrane cofactor protein)
- CFH, complementfactor H
- CFI, complement factor I
- CI, confidence interval
- COOH, carboxy terminal
- CR1, complement receptor 1
- Complement factor I
- FI, factor I protein
- GA, geographic atrophy
- GRS, genetic risk score
- Genetic variants
- Geographic atrophy
- HR, hazard ratio
- NH2, amino terminal
- NV, neovascular
- Neovascular disease
- OR, odds ratio
- SAS, Statistical Analysis System
- SLCS, Seddon Longitudinal Cohort Study
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Affiliation(s)
- Johanna M. Seddon
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Bernard Rosner
- Channing Division of Network Medicine, Harvard Medical School, Boston, Massachusetts
| | - Dikha De
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Tianxiao Huan
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Chan Medical School, Worcester, Massachusetts
| | - Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - John Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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Zelinger L, Martin TM, Advani J, Campello L, English MA, Kwong A, Weber C, Maykoski J, Sergeev YV, Fariss R, Chew EY, Klein ML, Swaroop A. Ultra-rare complement factor 8 coding variants in families with age-related macular degeneration. iScience 2023; 26:106417. [PMID: 37153444 PMCID: PMC10156737 DOI: 10.1016/j.isci.2023.106417] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 02/20/2023] [Accepted: 03/11/2023] [Indexed: 04/05/2023] Open
Abstract
Genome-wide association studies have uncovered 52 independent common and rare variants across 34 genetic loci, which influence susceptibility to age related macular degeneration (AMD). Of the 5 AMD-associated complement genes, complement factor H (CFH) and CFI exhibit a significant rare variant burden implicating a major contribution of the complement pathway to disease pathology. However, the efforts for developing AMD therapy have been challenging as of yet. Here, we report the identification of ultra-rare variants in complement factors 8A and 8B, two components of the terminal complement membrane attack complex (MAC), by whole exome sequencing of a cohort of AMD families. The identified C8 variants impact local interactions among proteins of C8 triplex in vitro, indicating their effect on MAC stability. Our results suggest that MAC, and not the early steps of the complement pathway, might be a more effective target for designing treatments for AMD.
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Affiliation(s)
- Lina Zelinger
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tammy M. Martin
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Jayshree Advani
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Laura Campello
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Milton A. English
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Alan Kwong
- Department of Biostatistics and Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA
- 23andMe, Inc, Sunnyvale, CA, USA
| | - Claire Weber
- Division of Epidemiology and Clinical Applications, Clinical Trials Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer Maykoski
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| | - Yuri V. Sergeev
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Robert Fariss
- Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Emily Y. Chew
- Division of Epidemiology and Clinical Applications, Clinical Trials Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Michael L. Klein
- Casey Eye Institute, Department of Ophthalmology, Oregon Health & Science University, Portland, OR, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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Huan T, Cheng SY, Tian B, Punzo C, Lin H, Daly M, Seddon JM. Identifying Novel Genes and Variants in Immune and Coagulation Pathways Associated with Macular Degeneration. OPHTHALMOLOGY SCIENCE 2023; 3:100206. [PMID: 36275200 PMCID: PMC9574715 DOI: 10.1016/j.xops.2022.100206] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/06/2022] [Accepted: 07/25/2022] [Indexed: 11/29/2022]
Abstract
Purpose To select individuals and families with a low genetic burden for age-related macular degeneration (AMD), to inform the clinical diagnosis of macular disorders, and to find novel genetic variants associated with maculopathies. Design Genetic association study based on targeted and whole-exome sequencing. Participants A total of 758 subjects (481 individuals with maculopathy and 277 controls), including 316 individuals in 72 families. Methods We focused on 150 genes involved in the complement, coagulation, and inflammatory pathways. Single-variant tests were performed on 7755 variants shared among ≥ 5 subjects using logistic regression. Gene-based tests were used to evaluate aggregate effects from rare and low-frequency variants (at minor allele frequency [MAF] ≤ 5% or ≤ 1%) in a gene using burden tests. For families whose affected members had a low burden of genetic risk based on known common and rare variants related to AMD, we searched for rare variants (MAF < 0.001) whose risk alleles occurred in ≥ 80% of affected individuals but not in controls. Immunohistochemistry was performed to determine the protein expression of a novel gene (coagulation factor II thrombin receptor-like 2 [F2RL2]) in retinal tissues. Main Outcome Measures Genotypes and phenotypes of macular degeneration. Results We confirmed the association of a synonymous variant in complement factor H (Ala473, rs2274700, proxy to intronic rs1410996, r 2 = 1) with maculopathy (odds ratio, 0.64; P = 4.5 × 10-4). Higher AMD polygenic risk scores (PRSs) were associated with intermediate and advanced AMD. Among families with low PRSs and no known rare variants for maculopathy, we identified 2 novel, highly penetrant missense rare variants in ADAM15, A disintegrin and metalloprotease, metallopeptidase domain 15 (p.Arg288Cys) and F2RL2 (p.Leu289Arg). Immunohistochemistry analyses revealed F2RL2 protein expression in cone photoreceptor outer segments and Müller glia cells of human and pig retinas. Coagulation factor II thrombin receptor-like 2 expression appeared increased in fibrotic areas in advanced AMD samples with neovascularization, suggesting that F2RL2 may play a role in the progression to advanced macular disease. Conclusions New missense rare variants in the genes ADAM15 and F2RL2 were associated with maculopathies. Results suggest that novel genes related to the coagulation and immune pathways may be involved in the pathogenesis of macular diseases.
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Key Words
- AMD, age-related macular degeneration
- ATP, adenosine triphosphate
- C3, complement component 3
- C9, complement component 9
- CADD, Combined Annotation Dependent Depletion
- CFH, complement factor H
- CFI, complement factor I
- Coagulation pathway, Immune pathways
- ENG, endoglin
- F2RL2, coagulation factor II thrombin receptor-like 2
- FANTOM5, functional annotation of the mammalian genome
- GS, glutamine synthetase
- GWAS, genome-wide association studies
- MAF, minor allele frequency
- Macular degeneration
- Maculopathy
- PECAM1, Platelet Endothelial Cell Adhesion Molecule 1
- PRS, polygenic risk score
- SKAT, sequence kernel association testing
- SNP, single nucleotide polymorphism
- TPM, tags per million
- Targeted sequencing
- WES, whole-exome sequencing
- Whole-exome sequencing
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Affiliation(s)
- Tianxiao Huan
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Shun-Yun Cheng
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Bo Tian
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Claudio Punzo
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Haijiang Lin
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Mark Daly
- Massachusetts General Hospital and Broad Institute, Cambridge, Massachusetts
| | - Johanna M. Seddon
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
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10
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de Jong S, Tang J, Clark SJ. Age-related macular degeneration: A disease of extracellular complement amplification. Immunol Rev 2023; 313:279-297. [PMID: 36223117 DOI: 10.1111/imr.13145] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Age-related macular degeneration (AMD) is a major cause of vision impairment in the Western World, and with the aging world population, its incidence is increasing. As of today, for the majority of patients, no treatment exists. Multiple genetic and biochemical studies have shown a strong association with components in the complement system and AMD, and evidence suggests a major role of remodeling of the extracellular matrix underlying the outer blood/retinal barrier. As part of the innate immune system, the complement cascade acts as a first-line defense against pathogens, and upon activation, its amplification loop ensures a strong, rapid, and sustained response. Excessive activation, however, can lead to host tissue damage and cause complement-associated diseases like AMD. AMD patients present with aberrant activation of the alternative pathway, especially in ocular tissues but also on a systemic level. Here, we review the latest findings of complement activation in AMD, and we will discuss in vivo observations made in human tissue, cellular models, the potential synergy of different AMD-associated pathways, and conclude on current clinical trials and the future outlook.
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Affiliation(s)
- Sarah de Jong
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.,Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Jiaqi Tang
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.,Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Simon J Clark
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.,Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.,Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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11
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Yednock T, Fong DS, Lad EM. C1q and the classical complement cascade in geographic atrophy secondary to age-related macular degeneration. Int J Retina Vitreous 2022; 8:79. [PMID: 36348407 PMCID: PMC9641935 DOI: 10.1186/s40942-022-00431-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/21/2022] [Indexed: 11/10/2022] Open
Abstract
Geographic atrophy (GA) secondary to age-related macular degeneration (AMD) is a retinal neurodegenerative disorder. Human genetic data support the complement system as a key component of pathogenesis in AMD, which has been further supported by pre-clinical and recent clinical studies. However, the involvement of the different complement pathways (classical, lectin, alternative), and thus the optimal complement inhibition target, has yet to be fully defined. There is evidence that C1q, the initiating molecule of the classical pathway, is a key driver of complement activity in AMD. C1q is expressed locally by infiltrating phagocytic cells and C1q-activating ligands are present at disease onset and continue to accumulate with disease progression. The accumulation of C1q on photoreceptor synapses with age and disease is consistent with its role in synapse elimination and neurodegeneration that has been observed in other neurodegenerative disorders. Furthermore, genetic deletion of C1q, local pharmacologic inhibition within the eye, or genetic deletion of downstream C4 prevents photoreceptor cell damage in mouse models. Hence, targeting the classical pathway in GA could provide a more specific therapeutic approach with potential for favorable efficacy and safety.
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Affiliation(s)
- Ted Yednock
- Annexon Biosciences, 1400 Sierra Point Parkway Building C, 2nd Floor, Brisbane, CA, 94005, USA
| | - Donald S Fong
- Annexon Biosciences, 1400 Sierra Point Parkway Building C, 2nd Floor, Brisbane, CA, 94005, USA.
| | - Eleonora M Lad
- Department of Ophthalmology, Duke University Medical Center, 2351 Erwin Rd, Durham, NC, 27705, USA
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12
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Shughoury A, Sevgi DD, Ciulla TA. Molecular Genetic Mechanisms in Age-Related Macular Degeneration. Genes (Basel) 2022; 13:1233. [PMID: 35886016 PMCID: PMC9316037 DOI: 10.3390/genes13071233] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/30/2022] [Accepted: 07/05/2022] [Indexed: 11/29/2022] Open
Abstract
Age-related macular degeneration (AMD) is among the leading causes of irreversible blindness worldwide. In addition to environmental risk factors, such as tobacco use and diet, genetic background has long been established as a major risk factor for the development of AMD. However, our ability to predict disease risk and personalize treatment remains limited by our nascent understanding of the molecular mechanisms underlying AMD pathogenesis. Research into the molecular genetics of AMD over the past two decades has uncovered 52 independent gene variants and 34 independent loci that are implicated in the development of AMD, accounting for over half of the genetic risk. This research has helped delineate at least five major pathways that may be disrupted in the pathogenesis of AMD: the complement system, extracellular matrix remodeling, lipid metabolism, angiogenesis, and oxidative stress response. This review surveys our current understanding of each of these disease mechanisms, in turn, along with their associated pathogenic gene variants. Continued research into the molecular genetics of AMD holds great promise for the development of precision-targeted, personalized therapies that bring us closer to a cure for this debilitating disease.
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Affiliation(s)
- Aumer Shughoury
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.S.); (D.D.S.)
| | - Duriye Damla Sevgi
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.S.); (D.D.S.)
| | - Thomas A. Ciulla
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (A.S.); (D.D.S.)
- Clearside Biomedical, Inc., Alpharetta, GA 30005, USA
- Midwest Eye Institute, Indianapolis, IN 46290, USA
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13
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Java A, Pozzi N, Schroeder MC, Hu Z, Huan T, Seddon JM, Atkinson J. Functional analysis of rare genetic variants in complement factor I in advanced age-related macular degeneration. Hum Mol Genet 2022; 31:3683-3693. [PMID: 35531992 PMCID: PMC9616575 DOI: 10.1093/hmg/ddac103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/07/2022] [Accepted: 04/28/2022] [Indexed: 11/14/2022] Open
Abstract
Factor I (FI) is a serine protease inhibitor of the complement system. Heterozygous rare genetic variants in complement factor I (CFI) are associated with advanced age-related macular degeneration (AMD). The clinical impact of these variants is unknown since a majority have not been functionally characterized and are classified as 'variants of uncertain significance' (VUS). This study assessed the functional significance of VUS in CFI. Our previous cross-sectional study using a serum-based assay demonstrated that CFI variants in advanced AMD can be categorized into three types. Type 1 variants cause a quantitative deficiency of FI. Type 2 variants demonstrate a qualitative deficiency. However, Type 3 variants consist of VUS that are less dysfunctional than Types 1 and 2 but are not as biologically active as wild type (WT). In this study, we employed site-directed mutagenesis followed by expression of the recombinant variant and a comprehensive set of functional assays to characterize nine Type 3 variants that were identified in 37 individuals. Our studies establish that the expression of the recombinant protein compared with WT is reduced for R202I, Q217H, S221Y and G263V. Further, G362A and N536K, albeit expressed normally, have significantly less cofactor activity. These results led to re-categorization of CFI variants R202I, Q217H, S221Y and G263V as Type 1 variants and to reclassification of N536K and G362A as Type 2. The variants K441R, Q462H and I492L showed no functional defect and remained as Type 3. This study highlights the utility of an in-depth biochemical analysis in defining the pathologic and clinical implications of complement variants underlying AMD.
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Affiliation(s)
- Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nicola Pozzi
- Department of Biochemistry and Molecular Biology, Edward A. Doisy Research Center, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Molly C Schroeder
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Zheng Hu
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Tianxiao Huan
- Department of Ophthalmology and Visual Sciences, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | | | - John Atkinson
- To whom correspondence should be addressed at: Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA. Tel: +1 3143628391; Fax: +1 3143621366;
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14
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Acar IE, Willems E, Kersten E, Keizer-Garritsen J, Kragt E, Bakker B, Galesloot TE, Hoyng CB, Fauser S, van Gool AJ, Lechanteur YTE, Koertvely E, Nogoceke E, Gloerich J, de Jonge MI, Lorés-Motta L, den Hollander AI. Semi-Quantitative Multiplex Profiling of the Complement System Identifies Associations of Complement Proteins with Genetic Variants and Metabolites in Age-Related Macular Degeneration. J Pers Med 2021; 11:jpm11121256. [PMID: 34945728 PMCID: PMC8705464 DOI: 10.3390/jpm11121256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/12/2021] [Accepted: 11/19/2021] [Indexed: 12/20/2022] Open
Abstract
Age-related macular degeneration (AMD) is a major cause of vision loss among the elderly in the Western world. The complement system has been identified as one of the main AMD disease pathways. We performed a comprehensive expression analysis of 32 complement proteins in plasma samples of 255 AMD patients and 221 control individuals using mass spectrometry-based semi-quantitative multiplex profiling. We detected significant associations of complement protein levels with age, sex and body-mass index (BMI), and potential associations of C-reactive protein, factor H related-2 (FHR-2) and collectin-11 with AMD. In addition, we confirmed previously described associations and identified new associations of AMD variants with complement levels. New associations include increased C4 levels for rs181705462 at the C2/CFB locus, decreased vitronectin (VTN) levels for rs11080055 at the TMEM97/VTN locus and decreased factor I levels for rs10033900 at the CFI locus. Finally, we detected significant associations between AMD-associated metabolites and complement proteins in plasma. The most significant complement-metabolite associations included increased high density lipoprotein (HDL) subparticle levels with decreased C3, factor H (FH) and VTN levels. The results of our study indicate that demographic factors, genetic variants and circulating metabolites are associated with complement protein components. We suggest that these factors should be considered to design personalized treatment approaches and to increase the success of clinical trials targeting the complement system.
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Affiliation(s)
- I. Erkin Acar
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
| | - Esther Willems
- Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (E.W.); (M.I.d.J.)
- Radboud Center for Infectious Diseases, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.K.-G.); (E.K.); (A.J.v.G.); (J.G.)
| | - Eveline Kersten
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
| | - Jenneke Keizer-Garritsen
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.K.-G.); (E.K.); (A.J.v.G.); (J.G.)
| | - Else Kragt
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.K.-G.); (E.K.); (A.J.v.G.); (J.G.)
| | - Bjorn Bakker
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
| | - Tessel E. Galesloot
- Department for Health Evidence, Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Carel B. Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
| | - Sascha Fauser
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, 124 Grenzacherstrasse, 4070 Basel, Switzerland; (S.F.); (E.K.); (E.N.)
| | - Alain J. van Gool
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.K.-G.); (E.K.); (A.J.v.G.); (J.G.)
| | - Yara T. E. Lechanteur
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
| | - Elod Koertvely
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, 124 Grenzacherstrasse, 4070 Basel, Switzerland; (S.F.); (E.K.); (E.N.)
| | - Everson Nogoceke
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, 124 Grenzacherstrasse, 4070 Basel, Switzerland; (S.F.); (E.K.); (E.N.)
| | - Jolein Gloerich
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.K.-G.); (E.K.); (A.J.v.G.); (J.G.)
| | - Marien I. de Jonge
- Laboratory of Medical Immunology, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (E.W.); (M.I.d.J.)
- Radboud Center for Infectious Diseases, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Laura Lorés-Motta
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, 124 Grenzacherstrasse, 4070 Basel, Switzerland; (S.F.); (E.K.); (E.N.)
| | - Anneke I. den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (I.E.A.); (E.K.); (B.B.); (C.B.H.); (Y.T.E.L.); (L.L.-M.)
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Correspondence:
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15
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Structural basis of soluble membrane attack complex packaging for clearance. Nat Commun 2021; 12:6086. [PMID: 34667172 PMCID: PMC8526713 DOI: 10.1038/s41467-021-26366-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 10/01/2021] [Indexed: 12/15/2022] Open
Abstract
Unregulated complement activation causes inflammatory and immunological pathologies with consequences for human disease. To prevent bystander damage during an immune response, extracellular chaperones (clusterin and vitronectin) capture and clear soluble precursors to the membrane attack complex (sMAC). However, how these chaperones block further polymerization of MAC and prevent the complex from binding target membranes remains unclear. Here, we address that question by combining cryo electron microscopy (cryoEM) and cross-linking mass spectrometry (XL-MS) to solve the structure of sMAC. Together our data reveal how clusterin recognizes and inhibits polymerizing complement proteins by binding a negatively charged surface of sMAC. Furthermore, we show that the pore-forming C9 protein is trapped in an intermediate conformation whereby only one of its two transmembrane β-hairpins has unfurled. This structure provides molecular details for immune pore formation and helps explain a complement control mechanism that has potential implications for how cell clearance pathways mediate immune homeostasis. To prevent unregulated complement activation, extracellular chaperones capture soluble precursors to the membrane attack complex (sMAC). Here, structural analysis of sMAC reveals how clusterin recognizes heterogeneous sMAC complexes and inhibits polymerization of complement protein C9.
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