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Koçyiğit E, Gövez NE, Arslan S, Ağagündüz D. A narrative review on dietary components and patterns and age-related macular degeneration. Nutr Res Rev 2024:1-28. [PMID: 38221852 DOI: 10.1017/s0954422424000015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Age-related macular degeneration (AMD) is one of the most prevalent eye diseases among the ageing population worldwide. It is a leading cause of blindness in individuals over 55, particularly in industrialised Western countries. The prevalence of AMD increases with age, and genetic factors and environmental influences are believed to contribute to its development. Among the environmental factors, diet plays a significant role in AMD. This review explores the association between dietary components, dietary patterns and AMD. Various nutrients, non-nutrient substances and dietary models that have the potential to counteract oxidative stress and inflammation, which are underlying mechanisms of AMD, are discussed. Consuming fruits, vegetables, fish and seafood, whole grains, olive oil, nuts and low-glycaemic-index foods has been highlighted as beneficial for reducing the risk of AMD. Adhering to the Mediterranean diet, which encompasses these elements, can be recommended as a dietary pattern for AMD. Furthermore, the modulation of the gut microbiota through dietary interventions and probiotics has shown promise in managing AMD.
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Affiliation(s)
- Emine Koçyiğit
- Department of Nutrition and Dietetics, Ordu University, Ordu, Türkiye
| | - Nazlıcan Erdoğan Gövez
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara, Türkiye
| | - Sabriye Arslan
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara, Türkiye
| | - Duygu Ağagündüz
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara, Türkiye
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2
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Emri E, Cappa O, Kelly C, Kortvely E, SanGiovanni JP, McKay BS, Bergen AA, Simpson DA, Lengyel I. Zinc Supplementation Induced Transcriptional Changes in Primary Human Retinal Pigment Epithelium: A Single-Cell RNA Sequencing Study to Understand Age-Related Macular Degeneration. Cells 2023; 12:773. [PMID: 36899910 PMCID: PMC10000409 DOI: 10.3390/cells12050773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/05/2023] Open
Abstract
Zinc supplementation has been shown to be beneficial to slow the progression of age-related macular degeneration (AMD). However, the molecular mechanism underpinning this benefit is not well understood. This study used single-cell RNA sequencing to identify transcriptomic changes induced by zinc supplementation. Human primary retinal pigment epithelial (RPE) cells could mature for up to 19 weeks. After 1 or 18 weeks in culture, we supplemented the culture medium with 125 µM added zinc for one week. RPE cells developed high transepithelial electrical resistance, extensive, but variable pigmentation, and deposited sub-RPE material similar to the hallmark lesions of AMD. Unsupervised cluster analysis of the combined transcriptome of the cells isolated after 2, 9, and 19 weeks in culture showed considerable heterogeneity. Clustering based on 234 pre-selected RPE-specific genes divided the cells into two distinct clusters, we defined as more and less differentiated cells. The proportion of more differentiated cells increased with time in culture, but appreciable numbers of cells remained less differentiated even at 19 weeks. Pseudotemporal ordering identified 537 genes that could be implicated in the dynamics of RPE cell differentiation (FDR < 0.05). Zinc treatment resulted in the differential expression of 281 of these genes (FDR < 0.05). These genes were associated with several biological pathways with modulation of ID1/ID3 transcriptional regulation. Overall, zinc had a multitude of effects on the RPE transcriptome, including several genes involved in pigmentation, complement regulation, mineralization, and cholesterol metabolism processes associated with AMD.
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Affiliation(s)
- Eszter Emri
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
- Section Ophthalmogenetics, Department of Human Genetics, Queen Emma Centre for Precision Medicine, Amsterdam UMC, Location AMC, 1105AZ Amsterdam, The Netherlands
| | - Oisin Cappa
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
| | - Caoimhe Kelly
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
| | - Elod Kortvely
- Immunology, Infectious Diseases and Ophthalmology (I2O) Discovery and Translational Area, Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland
| | - John Paul SanGiovanni
- Biosciences Research Laboratories, BIO5 Institute, University of Arizona, 1230 North Cherry Avenue, Tucson, AZ 85724, USA
| | - Brian S. McKay
- Department of Ophthalmology and Vision Science, University of Arizona, 1656 E. Mabel Street, Tucson, AZ 85724, USA
| | - Arthur A. Bergen
- Section Ophthalmogenetics, Department of Human Genetics, Queen Emma Centre for Precision Medicine, Amsterdam UMC, Location AMC, 1105AZ Amsterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN-KNAW), 1105AZ Amsterdam, The Netherlands
| | - David A. Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
| | - Imre Lengyel
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, UK
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3
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Kerboua KE, Lasla S, Kerboua MH, Djennouhat K. The blocking effect of zinc on complement factor H in vitro: further proof by the hemolytic assay of Pilar Sánchez-Corral. J Immunoassay Immunochem 2023; 44:309-312. [PMID: 36755442 DOI: 10.1080/15321819.2023.2173529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- Kheir Eddine Kerboua
- Laboratory of Desert Medicine, Faculty of Medicine, University of Kasdi Merbah, Ouargla, Algeria.,Laboratory of Immunology, Regional Military University Hospital of Oran, Oran, Algeria
| | - Saadia Lasla
- Laboratory of Immunology, Regional Military University Hospital of Oran, Oran, Algeria
| | - Maria-Hadjer Kerboua
- Laboratory of Desert Medicine, Faculty of Medicine, University of Kasdi Merbah, Ouargla, Algeria
| | - Kamel Djennouhat
- Laboratory of Immunology, University Hospital of Rouiba, Algiers
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4
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Jiang J, He S, Liu K, Yu K, Long P, Xiao Y, Liu Y, Yu Y, Wang H, Zhou L, Zhang X, He M, Guo H, Wu T, Yuan Y. Multiple plasma metals, genetic risk and serum complement C3, C4: A gene-metal interaction study. CHEMOSPHERE 2022; 291:132801. [PMID: 34752839 DOI: 10.1016/j.chemosphere.2021.132801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/23/2021] [Accepted: 11/04/2021] [Indexed: 06/13/2023]
Abstract
Exposure to metals and metalloids is widely related with human health, and could affect the function of immune system. The complement system links innate and adaptive immunity, and is critically involved in the pathogenesis of inflammatory and immune diseases. The third and fourth components of complement (C3, C4) play key roles in the complement system. However, few studies have examined the relations between multiple metals and complement levels. In this study, based on a total of 2977 participants from the Dongfeng-Tongji cohort, China, we investigated 17 plasma metals and serum C3, C4 levels, and calculated C3/C4-associated genetic risk scores (GRSs) using established single nucleotide polymorphisms. We further explored the potential gene-metal interactions on C3 and C4. After multivariable adjustment, an increment of 10-standard deviation increase in natural log-transformed exposure concentrations of plasma copper was associated with 0.549 (0.489, 0.608) (FDR <0.0001), and 1.146 (0.999, 1.294) (FDR <0.0001) higher natural log-transformed serum C3 and C4 levels, respectively. While each increment of 10-standard deviation of natural log-transformed zinc was associated with a difference of 0.083 (0.024, 0.143) (FDR = 0.049) and 0.007 (-0.138, 0.152) (FDR = 0.935) in log-transformed C3 and C4 levels, respectively. Participants with higher GRS had higher C3 and C4 levels. Furthermore, we found a significant interaction between arsenic exposure and C3-GRS in relation to C3 level (Pinteraction = 0.0096). Our results suggested that plasma arsenic would modify the association between C3 genetic predisposition and serum C3 level. We provide new insight into metals exposure on the human immune system. These findings require replication in future research.
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Affiliation(s)
- Jing Jiang
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Shiqi He
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Kang Liu
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Kuai Yu
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Pinpin Long
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yang Xiao
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yiyi Liu
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yanqiu Yu
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hao Wang
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Lue Zhou
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiaomin Zhang
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Meian He
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Huan Guo
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Tangchun Wu
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yu Yuan
- Department of Occupational and Environmental Health, Key Laboratory of Environment and Health, Ministry of Education and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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5
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Baarz BR, Rink L. Rebalancing the unbalanced aged immune system - A special focus on zinc. Ageing Res Rev 2022; 74:101541. [PMID: 34915196 DOI: 10.1016/j.arr.2021.101541] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/18/2021] [Accepted: 12/09/2021] [Indexed: 02/08/2023]
Abstract
Nowadays, aging is understood as a dynamic and multifaceted dysregulation process that spares almost no human organ or cell. The immune system being among the most affected, it has been shown predominantly that its integrity determines the tightrope walk between the difference of escaping or suffering from age-related diseases. Next to drug-based anti-aging strategies, micronutrient intervention may represent an emerging but less radical way to slow immune aging. While a sufficient supply of a variety of micronutrients is undeniably important, adequate intake of the trace element zinc appears to tower over others in terms of reaching old age. Inconveniently, zinc deficiency prevalence among the elderly is high, which in turn contributes to increased susceptibility to infection, decreased anti-tumor immunity as well as attenuated response to vaccination. Driven by this research, this review aims to provide a comprehensive and up-to-date overview of the various rebalancing capabilities of zinc in the unbalanced immune system of the elderly. This includes an in-depth and cell type-centered discussion on the role of zinc in immunosenescence and inflammaging. We further address upcoming translational aspects e.g. how zinc deficiency promotes the flourishing of certain pathogenic taxa of the gut microbiome and how zinc supply counteracts such alterations in a manner that may contribute to longevity. In the light of the ongoing COVID-19 pandemic, we also briefly review current knowledge on the interdependency between age, zinc status, and respiratory infections. Based on two concrete examples and considering the latest findings in the field we conclude our remarks by outlining tremendous parallels between suboptimal zinc status and accelerated aging on the one hand and an optimized zinc status and successful aging on the other hand.
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Sakajiri T, Nakatsuji M, Teraoka Y, Furuta K, Ikuta K, Shibusa K, Sugano E, Tomita H, Inui T, Yamamura T. Zinc mediates the interaction between ceruloplasmin and apo-transferrin for the efficient transfer of Fe(III) ions. Metallomics 2021; 13:6427378. [PMID: 34791391 DOI: 10.1093/mtomcs/mfab065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 11/02/2021] [Indexed: 11/14/2022]
Abstract
Fe(II) exported from cells is oxidized to Fe(III), possibly by a multi-copper ferroxidase (MCF) such as ceruloplasmin (CP), to efficiently bind with the plasma iron transport protein transferrin (TF). As unbound Fe(III) is highly insoluble and reactive, its release into the blood during the transfer from MCF to TF must be prevented. A likely mechanism for preventing the release of unbound Fe(III) is via direct interaction between MCF and TF; however, the occurrence of this phenomenon remains controversial. This study aimed to reveal the interaction between these proteins, possibly mediated by zinc. Using spectrophotometric, isothermal titration calorimetric, and surface plasmon resonance methods, we found that Zn(II)-bound CP bound to iron-free TF (apo-TF) with a Kd of 4.2 μM and a stoichiometry CP:TF of ∼2:1. Computational modeling of the complex between CP and apo-TF predicted that each of the three Zn(II) ions that bind to CP further binds to acidic amino acid residues of apo-TF to play a role as a cross-linker connecting both proteins. Domain 4 of one CP molecule and domain 6 of the other CP molecule fit tightly into the clefts in the N- and C-lobes of apo-TF, respectively. Upon the binding of two Fe(III) ions to apo-TF, the resulting diferric TF [Fe(III)2TF] dissociated from CP by conformational changes in TF. In human blood plasma, zinc deficiency reduced the production of Fe(III)2TF and concomitantly increased the production of non-TF-bound iron. Our findings suggest that zinc may be involved in the transfer of iron between CP and TF.
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Affiliation(s)
- Tetsuya Sakajiri
- Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.,Faculty of Nutritional Sciences, the University of Morioka, 808 Sunakomi, Takizawa, Iwate 020-0694, Japan.,Qualtec Co. Ltd., 4-230 Sambo-cho, Sakai, Osaka 590-0906, Japan.,Department of Nutrition, Kyushu Nutrition Welfare University, 5-1-1 Shimoitozu, Kitakyushu Kokurakita-ku, Fukuoka 803-0846, Japan
| | - Masatoshi Nakatsuji
- Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yoshiaki Teraoka
- Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Kosuke Furuta
- Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Katsuya Ikuta
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510, Japan.,Japanese Red Cross Hokkaido Blood Center, 2-1 Nijuyonken, Nishi-ku, Sapporo, Hokkaido 063-0802, Japan
| | - Kotoe Shibusa
- Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510, Japan.,Hokkaido System Science Co., Ltd., 2-1 Shinkawa Nishi, Kita-ku, Sapporo, Hokkaido 001-0932, Japan
| | - Eriko Sugano
- Department of Chemistry and Biological Sciences, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Hiroshi Tomita
- Department of Chemistry and Biological Sciences, Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Takashi Inui
- Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Takaki Yamamura
- Laboratory of Biological Macromolecules, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.,Faculty of Nutritional Sciences, the University of Morioka, 808 Sunakomi, Takizawa, Iwate 020-0694, Japan
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7
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Mano F, Sakata S, Chang KC, Mano T. Effects of Zinc Acetate Hydrate Treatment on Serum Oxidative Stress Markers in Patients with Macular Drusen. J Ocul Pharmacol Ther 2021; 37:518-524. [PMID: 34558962 DOI: 10.1089/jop.2021.0031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose: To measure the serum levels of the oxidative stress markers superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPx) and compare them before and after zinc supplementation in patients with early age-related macular degeneration (AMD). Methods: We measured serum zinc levels in 65 patients with early AMD. Of these, 29 patients with macular drusen and a serum zinc level <80 μg/dL received oral zinc acetate dihydrate (50 mg/day). Serum trace metal levels (zinc and copper) and oxidative stress marker levels (SOD, MDA, and GPx) were measured at baseline and 12 weeks after the treatment. The macular drusen areas and best-corrected visual acuity were evaluated in 24 participants who attended the 3-month follow-up. Results: MDA level was significantly decreased from baseline to 12 weeks after zinc administration (170.5 ± 100.9 vs. 148.3 ± 57.9 pmol/mL, P = 0.03), while SOD was significantly increased from baseline to 12 weeks after zinc intake (4.2 ± 0.9 vs. 4.6 ± 0.9 U/mL, P = 0.03). The serum zinc level was significantly correlated with the MDA level (P = 0.03, ρ = -0.26). The area of soft drusen was significantly decreased after zinc treatment (1,936,654.9 ± 1,348,267.6 vs. 966,883.9 ± 719,938.1 μmm2, P = 0.04). Conclusions: The levels of oxidative stress markers MDA and SOD decreased and increased, respectively, after oral zinc administration to 24 patients with AMD. The therapeutic effect of zinc treatment on drusen area might differ depending on the drusen phenotype in early AMD.
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Affiliation(s)
- Fukutaro Mano
- Department of Ophthalmology and Kindai University Faculty of Medicine, Osakasayama, Japan.,Suita Tokushukai Hospital Eye Center, Suita, Japan
| | - Shoei Sakata
- Center for Instrumental Analysis, Kindai University Faculty of Medicine, Osakasayama, Japan
| | | | - Tomiya Mano
- Suita Tokushukai Hospital Eye Center, Suita, Japan
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Maya-Maldonado K, Cardoso-Jaime V, González-Olvera G, Osorio B, Recio-Tótoro B, Manrique-Saide P, Rodríguez-Sánchez IP, Lanz-Mendoza H, Missirlis F, Hernández-Hernández FDLC. Mosquito metallomics reveal copper and iron as critical factors for Plasmodium infection. PLoS Negl Trop Dis 2021; 15:e0009509. [PMID: 34161336 PMCID: PMC8221525 DOI: 10.1371/journal.pntd.0009509] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 05/26/2021] [Indexed: 11/18/2022] Open
Abstract
Iron and copper chelation restricts Plasmodium growth in vitro and in mammalian hosts. The parasite alters metal homeostasis in red blood cells to its favor, for example metabolizing hemoglobin to hemozoin. Metal interactions with the mosquito have not, however, been studied. Here, we describe the metallomes of Anopheles albimanus and Aedes aegypti throughout their life cycle and following a blood meal. Consistent with previous reports, we found evidence of maternal iron deposition in embryos of Ae. aegypti, but less so in An. albimanus. Sodium, potassium, iron, and copper are present at higher concentrations during larval developmental stages. Two An. albimanus phenotypes that differ in their susceptibility to Plasmodium berghei infection were studied. The susceptible white stripe (ws) phenotype was named after a dorsal white stripe apparent during larval stages 3, 4, and pupae. During larval stage 3, ws larvae accumulate more iron and copper than the resistant brown stripe (bs) phenotype counterparts. A similar increase in copper and iron accumulation was also observed in the susceptible ws, but not in the resistant bs phenotype following P. berghei infection. Feeding ws mosquitoes with extracellular iron and copper chelators before and after receiving Plasmodium-infected blood protected from infection and simultaneously affected follicular development in the case of iron chelation. Unexpectedly, the application of the iron chelator to the bs strain reverted resistance to infection. Besides a drop in iron, iron-chelated bs mosquitoes experienced a concomitant loss of copper. Thus, the effect of metal chelation on P. berghei infectivity was strain-specific.
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Affiliation(s)
- Krystal Maya-Maldonado
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav, Ciudad de México, México
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Victor Cardoso-Jaime
- Departamento de Infectómica y Patogénesis Molecular, Cinvestav, Ciudad de México, México
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Gabriela González-Olvera
- Unidad Colaborativa para Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Beatriz Osorio
- Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav, Ciudad de México, México
| | - Benito Recio-Tótoro
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Pablo Manrique-Saide
- Unidad Colaborativa para Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Iram Pablo Rodríguez-Sánchez
- Laboratorio de Fisiología Molecular y Estructural, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Humberto Lanz-Mendoza
- Centro de Investigaciones sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Fanis Missirlis
- Departamento de Fisiología, Biofísica y Neurociencias, Cinvestav, Ciudad de México, México
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9
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Altay L, Lemke J, Schröder-Braunstein J, Gietzelt C, Sitnilska V, Schaub F, Cursiefen C, Enders P, Fauser S. Ocular and systemic complement activation during anti-VEGF treatment and AREDS2 dietary supplementation in neovascular age-related macular degeneration. Ophthalmologica 2021; 245:258-264. [PMID: 34034256 DOI: 10.1159/000516885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/17/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Lebriz Altay
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany,
| | - Julia Lemke
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | | | - Caroline Gietzelt
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Vasilena Sitnilska
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Friederike Schaub
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Claus Cursiefen
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Philip Enders
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Sascha Fauser
- Department of Ophthalmology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany
- F. Hoffmann-La Roche AG, Basel, Switzerland
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10
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Peoples N, Strang C. Complement Activation in the Central Nervous System: A Biophysical Model for Immune Dysregulation in the Disease State. Front Mol Neurosci 2021; 14:620090. [PMID: 33746710 PMCID: PMC7969890 DOI: 10.3389/fnmol.2021.620090] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/12/2021] [Indexed: 01/08/2023] Open
Abstract
Complement, a feature of the innate immune system that targets pathogens for phagocytic clearance and promotes inflammation, is tightly regulated to prevent damage to host tissue. This regulation is paramount in the central nervous system (CNS) since complement proteins degrade neuronal synapses during development, homeostasis, and neurodegeneration. We propose that dysregulated complement, particularly C1 or C3b, may errantly target synapses for immune-mediated clearance, therefore highlighting regulatory failure as a major potential mediator of neurological disease. First, we explore the mechanics of molecular neuroimmune relationships for the regulatory proteins: Complement Receptor 1, C1-Inhibitor, Factor H, and the CUB-sushi multiple domain family. We propose that biophysical and chemical principles offer clues for understanding mechanisms of dysregulation. Second, we describe anticipated effects to CNS disease processes (particularly Alzheimer's Disease) and nest our ideas within existing basic science, clinical, and epidemiological findings. Finally, we illustrate how the concepts presented within this manuscript provoke new ways of approaching age-old neurodegenerative processes. Every component of this model is testable by straightforward experimentation and highlights the untapped potential of complement dysregulation as a driver of CNS disease. This includes a putative role for complement-based neurotherapeutic agents and companion biomarkers.
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Kaufman SR, Yoganathan P, Small KW, Rusia D, Pachydaki SI, Conti SM, Wenz RE, Gersman MA, Shaya FS, Kustra R. Genetics and Age-Related Eye Disease Study Formulation Interaction in Neovascular Age-Related Macular Degeneration. JOURNAL OF VITREORETINAL DISEASES 2021; 5:46-52. [PMID: 37009583 PMCID: PMC9976046 DOI: 10.1177/2474126420941713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose: This work aims to determine whether previously defined genotype risk groups interact with Age-Related Eye Disease Study formulation (AREDS-F) use in progression to neovascular age-related macular degeneration (nvAMD). Methods: We conducted a case-only study of 265 nvAMD patients. Patients were anonymously genotyped at the complement factor H and age-related maculopathy susceptibility 2 loci and segregated into genotype groups (GTGs) defined by specific combinations of risk alleles. Physicians, who were blind to patients’ GTGs, obtained patients’ AREDS-F use history. The facility performing genetic analysis was blind to the AREDS-F use history. We used logistic analysis to estimate the interaction coefficient between AREDS-F use and GTG 2 vs GTG 3 in a general-population model. Results: The odds ratio of numbers of patients reporting prior AREDS-F use to nonuse for GTG 2 vs GTG 3 was 4.18 ( P = .001). Logistic regression, correcting for nongenetic risk factors, gave an estimate of the β for interaction of AREDS-F with genotype of 1.57 ( P = .001). This estimates a corrected odds ratio associated with the effect of interaction of 4.81 between those in GTG 2 compared with those in GTG 3. Conclusions: Our data indicate an interaction between GTGs and AREDS-F use that is consistent in size and direction with previously published reports, which had found that using AREDS-F supplements significantly increases the risk of nvAMD for some users and significantly protects other users.
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Affiliation(s)
| | - Pradeepa Yoganathan
- Kresge Eye Institute, Wayne State University, Detroit, MI, USA
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Laurel Eye Clinic, Brookville, PA, USA
| | | | | | | | | | | | | | | | - Rafal Kustra
- Dana Lana School of Public Health, University of Toronto, Toronto, ON, Canada
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12
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Wessels I, Fischer HJ, Rink L. Update on the multi-layered levels of zinc-mediated immune regulation. Semin Cell Dev Biol 2020; 115:62-69. [PMID: 33323322 DOI: 10.1016/j.semcdb.2020.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/10/2020] [Accepted: 11/10/2020] [Indexed: 11/15/2022]
Abstract
The significance of zinc for an efficient immune response is well accepted. During zinc deficiency, an increase in the myeloid to lymphoid immune cells ratio was observed. This results in a disturbed balance of pro- and anti-inflammatory processes as well as defects in tolerance during infections. Consequently, instead of efficiently defending the body against invading pathogens, damage of host cells is frequently observed. This explains the increased susceptibility to infections and their severe progression observed for zinc deficient individuals as well as the association of autoimmune diseases with low serum zinc levels. Together with the advances in techniques for investigating cellular development, communication and intracellular metabolism, our understanding of the mechanisms underlying the benefits of zinc for human health and the detriments of zinc deficiency has much improved. As analyses of the zinc status and effects of zinc supplementation were more frequently included into clinical studies, our knowledge of the association of zinc deficiency to a variety of diseases was strongly improved. Still there are several areas in zinc biology that require further in-depth investigation such as the interaction with other nutritional elements, the direct association between zinc transportation, membrane-structure, receptors, and signaling as well as its role in cell degeneration. This article will describe our current understanding of the role of zinc during the immune response focusing on the most recent findings and underlying mechanisms. Research questions that need to be addressed in the future will be discussed as well.
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Affiliation(s)
- Inga Wessels
- Institute of Immunology, Faculty of Medicine, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany.
| | - Henrike J Fischer
- Institute of Immunology, Faculty of Medicine, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany.
| | - Lothar Rink
- Institute of Immunology, Faculty of Medicine, RWTH Aachen University, Pauwelsstr. 30, 52074 Aachen, Germany.
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13
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Heesterbeek TJ, Rouhi-Parkouhi M, Church SJ, Lechanteur YT, Lorés-Motta L, Kouvatsos N, Clark SJ, Bishop PN, Hoyng CB, den Hollander AI, Unwin RD, Day AJ. Association of plasma trace element levels with neovascular age-related macular degeneration. Exp Eye Res 2020; 201:108324. [PMID: 33098886 PMCID: PMC7773981 DOI: 10.1016/j.exer.2020.108324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/05/2020] [Accepted: 10/19/2020] [Indexed: 02/07/2023]
Abstract
Although the triggers causing angiogenesis in the context of neovascular age-related macular degeneration (nAMD) are not fully understood, oxidative stress is likely involved. Oxidative stress in the eye can occur through exposure of macular tissues to sunlight and local or systemic exposure to oxidative stressors associated with environmental or lifestyle factors. Because trace elements have been implicated as regulators of oxidative stress and cellular antioxidant defense mechanisms, we hypothesized that they may play a role as a risk factor, modifying the progression toward nAMD. Herein, we determined whether levels of human plasma trace elements are different in 236 individuals with nAMD compared to 236 age-matched controls without AMD. Plasma levels of 16 trace elements including arsenic, barium, calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, lead, antimony, selenium, vanadium and zinc were measured using inductively coupled plasma mass spectrometry. Associations of trace elements with demographic, environmental and lifestyle factors and AMD-associated genetic variants were assessed. Elevated levels of barium and cadmium and reduced levels of chromium were observed in nAMD patients compared to controls. Mean plasma concentrations of barium were 1.35 μg/L (standard deviation [SD] 0.71) in nAMD and 1.15 μg/L (SD 0.63) in controls (P = 0.001). Mean levels of chromium were 0.37 μg/L (SD 0.22) in nAMD and 0.46 μg/L (SD 0.34) in controls (P = 0.001). Median levels for cadmium, which were not normally distributed, were 0.016 μg/L (interquartile range [IQR] 0.001-0.026) in nAMD and 0.012 μg/L (IQR 0.001-0.022) in controls (P = 0.002). Comparison of the Spearman's correlation coefficients between nAMD patients and controls identified a difference in correlations for 8 trace elements. Cadmium levels were associated with the smoking status (P < 0.001), while barium levels showed a trend of association with the usage of antihypertensive drugs. None of the AMD-associated genetic variants were associated with any trace element levels. In conclusion, in this case-control study we detected elevated plasma levels of barium and cadmium and reduced plasma levels of chromium in nAMD patients. An imbalance in plasma trace elements, which is most likely driven by environmental and lifestyle factors, might have a role in the pathogenesis of AMD. These trace elements may be incorporated as biomarkers into models for prediction of disease risk and progression. Additionally, population-based preventive strategies to decrease Cd exposure, especially by the cessation of smoking, could potentially reduce the burden of nAMD. Future studies are warranted to investigate whether supplementation of Cr would have a beneficial effect on nAMD.
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Affiliation(s)
- Thomas J Heesterbeek
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mansour Rouhi-Parkouhi
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester, M13 9PT, UK
| | - Stephanie J Church
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Core Technology Facility, Grafton Street, Manchester, M13 9NT, UK
| | - Yara T Lechanteur
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Laura Lorés-Motta
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nikolaos Kouvatsos
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester, M13 9PT, UK
| | - Simon J Clark
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK; Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Elfriede-Aulhorn-Straße 7, 72076, Tübingen, Germany
| | - Paul N Bishop
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK; Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester M13 9WL, UK
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Richard D Unwin
- Stoller Biomarker Discovery Centre and Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology Medicine and Health, The University of Manchester, CityLabs 1.0 (3rd Floor), Nelson Street, Manchester, M13 9NQ, UK
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology & Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester, M13 9PT, UK; Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester, M13 9PT, UK.
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Ren C, Liu W, Yin X, Zhang B, Lu P. Renin-Angiotensin System Inhibitor Usage and Age-Related Macular Degeneration among Hypertensive Patients: Results from the National Health and Nutrition Examination Survey, 2005-2008. J Ophthalmol 2020; 2020:4252031. [PMID: 32676201 PMCID: PMC7333042 DOI: 10.1155/2020/4252031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/08/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To assess whether renin-angiotensin system inhibitor (RASI) utilization is associated with age-related macular degeneration (AMD) prevalence among hypertensive patients. METHODS A US population-based, cross-sectional study was conducted. 3,023 hypertensive participants aged 40 years and older with gradable retinal images and ascertained RASI usage in the National Health and Nutrition Examination Survey (NHANES), 2005-2008, were finally enrolled into the study. RASI usage was obtained by interview, and AMD was determined through retinal image assessment. We performed multivariable analyses to assess the relationship between utilization of RASIs and AMD prevalence. We also took drug treatment duration into account, in order to better understand the effects of RASIs. RESULTS Multivariable logistic regression analyses revealed that AMD prevalence had no significant association with RASI usage but was inversely correlated with RASI treatment duration (odds ratio (OR) = 0.87, 95% confidence interval (CI) = 0.78-0.98, p=0.02). Long-term usage (>5 years) of RASIs was significantly associated with not only reduced overall risk of AMD (OR = 0.23, 95% CI = 0.14-0.38, p < 0.001) but also lower propensity to have early (OR = 0.23, 95% CI = 0.14-0.37, p < 0.001) and late (OR = 0.25, 95% CI = 0.07-0.87, p=0.03) AMD. Furthermore, long-term RASI users were less prone to develop soft drusen (OR = 0.67, 95% CI = 0.45-0.99, p=0.04) and geographic atrophy (GA) (OR = 0.39, 95% CI = 0.22-0.71, p=0.003). CONCLUSIONS Evidence supporting that RASI utilization could directly protect against AMD in hypertensive patients was still insufficient, but long-term RASI treatment seemed to be beneficial for both early and late AMD, implicating a promising therapeutic approach that RASIs might offer for AMD prevention and management.
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Affiliation(s)
- Chi Ren
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou 215006, China
| | - Weiming Liu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou 215006, China
| | - Xue Yin
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou 215006, China
| | - Bingyu Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou 215006, China
| | - Peirong Lu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou 215006, China
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15
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Gombart AF, Pierre A, Maggini S. A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection. Nutrients 2020; 12:E236. [PMID: 31963293 PMCID: PMC7019735 DOI: 10.3390/nu12010236] [Citation(s) in RCA: 564] [Impact Index Per Article: 141.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 02/07/2023] Open
Abstract
Immune support by micronutrients is historically based on vitamin C deficiency and supplementation in scurvy in early times. It has since been established that the complex, integrated immune system needs multiple specific micronutrients, including vitamins A, D, C, E, B6, and B12, folate, zinc, iron, copper, and selenium, which play vital, often synergistic roles at every stage of the immune response. Adequate amounts are essential to ensure the proper function of physical barriers and immune cells; however, daily micronutrient intakes necessary to support immune function may be higher than current recommended dietary allowances. Certain populations have inadequate dietary micronutrient intakes, and situations with increased requirements (e.g., infection, stress, and pollution) further decrease stores within the body. Several micronutrients may be deficient, and even marginal deficiency may impair immunity. Although contradictory data exist, available evidence indicates that supplementation with multiple micronutrients with immune-supporting roles may modulate immune function and reduce the risk of infection. Micronutrients with the strongest evidence for immune support are vitamins C and D and zinc. Better design of human clinical studies addressing dosage and combinations of micronutrients in different populations are required to substantiate the benefits of micronutrient supplementation against infection.
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Affiliation(s)
- Adrian F. Gombart
- Linus Pauling Institute, Department of Biochemistry and Biophysics, Oregon State University, 307 Linus Pauling Science Center, Corvallis, OR 97331, USA;
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16
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Regulation of regulators: Role of the complement factor H-related proteins. Semin Immunol 2019; 45:101341. [PMID: 31757608 DOI: 10.1016/j.smim.2019.101341] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/07/2019] [Accepted: 10/24/2019] [Indexed: 01/15/2023]
Abstract
The complement system, while being an essential and very efficient effector component of innate immunity, may cause damage to the host and result in various inflammatory, autoimmune and infectious diseases or cancer, when it is improperly activated or regulated. Factor H is a serum glycoprotein and the main regulator of the activity of the alternative complement pathway. Factor H, together with its splice variant factor H-like protein 1 (FHL-1), inhibits complement activation at the level of the central complement component C3 and beyond. In humans, there are also five factor H-related (FHR) proteins, whose function is poorly characterized. While data indicate complement inhibiting activity for some of the FHRs, there is increasing evidence that FHRs have an opposite role compared with factor H and FHL-1, namely, they enhance complement activation directly and also by competing with the regulators FH and FHL-1. This review summarizes the current stand and recent data on the roles of factor H family proteins in health and disease, with focus on the function of FHR proteins.
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17
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Coverdale JPC, Barnett JP, Adamu AH, Griffiths EJ, Stewart AJ, Blindauer CA. A metalloproteomic analysis of interactions between plasma proteins and zinc: elevated fatty acid levels affect zinc distribution. Metallomics 2019; 11:1805-1819. [PMID: 31612889 DOI: 10.1039/c9mt00177h] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Serum albumin is a highly abundant plasma protein associated with the transport of metal ions, pharmaceuticals, fatty acids and a variety of small molecules in the blood. Once thought of as a molecular 'sponge', mounting evidence suggests that the albumin-facilitated transport of chemically diverse entities is not independent. One such example is the transport of Zn2+ ions and non-esterified 'free' fatty acids (FFAs) by albumin, both of which bind at high affinity sites located in close proximity. Our previous research suggests that their transport in blood plasma is linked via an allosteric mechanism on serum albumin. In direct competition, albumin-bound FFAs significantly decrease the binding capacity of albumin for Zn2+, with one of the predicted consequences being a change in plasma/serum zinc speciation. Using liquid chromatography (LC), ICP-MS and fluorescence assays, our work provides a quantitative assessment of this phenomenon, and finds that in the presence of high FFA concentrations encountered in various physiological conditions, a significant proportion of albumin-bound Zn2+ is re-distributed amongst plasma/serum proteins. Using peptide mass fingerprinting and immunodetection, we identify candidate acceptor proteins for Zn2+ liberated from albumin. These include histidine-rich glycoprotein (HRG), a multifunctional protein associated with the regulation of blood coagulation, and members of the complement system involved in the innate immune response. Our findings highlight how FFA-mediated changes in extracellular metal speciation might contribute to the progression of certain pathological conditions.
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Affiliation(s)
| | - James P Barnett
- Department of Life Sciences, Birmingham City University, Edgbaston, B15 3TN, UK
| | - Adamu H Adamu
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
| | - Ellie J Griffiths
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
| | - Alan J Stewart
- School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
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Gilbert R, Peto T, Lengyel I, Emri E. Zinc Nutrition and Inflammation in the Aging Retina. Mol Nutr Food Res 2019; 63:e1801049. [PMID: 31148351 DOI: 10.1002/mnfr.201801049] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 04/18/2019] [Indexed: 12/16/2022]
Abstract
Zinc is an essential nutrient for human health. It plays key roles in maintaining protein structure and stability, serves as catalytic factor for many enzymes, and regulates diverse fundamental cellular processes. Zinc is important in affecting signal transduction and, in particular, in the development and integrity of the immune system, where it affects both innate and adaptive immune responses. The eye, especially the retina-choroid complex, has an unusually high concentration of zinc compared to other tissues. The highest amount of zinc is concentrated in the retinal pigment epithelium (RPE) (RPE-choroid, 292 ± 98.5 µg g-1 dry tissue), followed by the retina (123 ± 62.2 µg g-1 dry tissue). The interplay between zinc and inflammation has been explored in other parts of the body but, so far, has not been extensively researched in the eye. Several lines of evidence suggest that ocular zinc concentration decreases with age, especially in the context of age-related disease. Thus, a hypothesis that retinal function could be modulated by zinc nutrition is proposed, and subsequently trialled clinically. In this review, the distribution and the potential role of zinc in the retina-choroid complex is outlined, especially in relation to inflammation and immunity, and the clinical studies to date are summarized.
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Affiliation(s)
- Rosie Gilbert
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, EC1V 2PD, UK.,UCL Institute of Ophthalmology, Bath Street, London, EC1V 2EL, UK
| | - Tunde Peto
- School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, Ireland
| | - Imre Lengyel
- UCL Institute of Ophthalmology, Bath Street, London, EC1V 2EL, UK.,School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, Ireland
| | - Eszter Emri
- School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, Ireland
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An Expanded Conformation of an Antibody Fab Region by X-Ray Scattering, Molecular Dynamics, and smFRET Identifies an Aggregation Mechanism. J Mol Biol 2019; 431:1409-1425. [PMID: 30776431 DOI: 10.1016/j.jmb.2019.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/06/2019] [Accepted: 02/06/2019] [Indexed: 11/20/2022]
Abstract
Protein aggregation is the underlying cause of many diseases, and also limits the usefulness of many natural and engineered proteins in biotechnology. Better mechanistic understanding and characterization of aggregation-prone states is needed to guide protein engineering, formulation, and drug-targeting strategies that prevent aggregation. While several final aggregated states-notably amyloids-have been characterized structurally, very little is known about the native structural conformers that initiate aggregation. We used a novel combination of small-angle x-ray scattering (SAXS), atomistic molecular dynamic simulations, single-molecule Förster resonance energy transfer, and aggregation-prone region predictions, to characterize structural changes in a native humanized Fab A33 antibody fragment, that correlated with the experimental aggregation kinetics. SAXS revealed increases in the native state radius of gyration, Rg, of 2.2% to 4.1%, at pH 5.5 and below, concomitant with accelerated aggregation. In a cutting-edge approach, we fitted the SAXS data to full MD simulations from the same conditions and located the conformational changes in the native state to the constant domain of the light chain (CL). This CL displacement was independently confirmed using single-molecule Förster resonance energy transfer measurements with two dual-labeled Fabs. These conformational changes were also found to increase the solvent exposure of a predicted APR, suggesting a likely mechanism through which they promote aggregation. Our findings provide a means by which aggregation-prone conformational states can be readily determined experimentally, and thus potentially used to guide protein engineering, or ligand binding strategies, with the aim of stabilizing the protein against aggregation.
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On the origin of proteins in human drusen: The meet, greet and stick hypothesis. Prog Retin Eye Res 2018; 70:55-84. [PMID: 30572124 DOI: 10.1016/j.preteyeres.2018.12.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/12/2022]
Abstract
Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplemented the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These "drusenomics" studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may "meet, greet and stick" to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.
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21
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Kustra R, Awh CC, Rojas-Fernandez C, Zanke B. CFH and ARMS2 Polymorphisms Interact with Zinc Supplements in Cognitive Impairment in the Women's Health Initiative Hormone Trial. J Alzheimers Dis 2018; 66:707-715. [PMID: 30320589 DOI: 10.3233/jad-180673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND An interaction between genetic variants in complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) and high-dose zinc supplementation on progression to advanced age-related macular degeneration (AMD) exists. Because cognitive impairment (CI) is associated with AMD, we used data from the Women's Health Initiative (WHI) to search for a zinc/genetics interaction. OBJECTIVE To study the interaction of chronic zinc supplementation with genetic variants in CFH and ARMS2 on the development of CI. BACKGROUND Zinc dietary supplements, CFH and ARMS2 genotypes, and serial mental status was analyzed in participants with available genetic data (n = 7,483). Cognition was assessed using the Modified Mini-Mental State Examination. The development of CI over 5 years was analyzed by genotype and zinc intake using a repeated measures logistic regression model. RESULTS Zinc supplementation of approximately 15 mg/day was associated with decreased development of CI in women with 1 or 2 CFH and no ARMS2 risk alleles (OR = 0.46: 1 CFH risk allele; 0.20: 2 CFH risk alleles; p = 0.002). CONCLUSION Low-dose zinc (approximately 15 mg) is associated with reduced CI in women with 2 CFH and 0 ARMS2 AMD risk alleles. This interaction is opposite in direction to that observed in AMD, where patients with 2 CFH and 0 ARMS2 risk alleles had increased progression to neovascular AMD if treated with 80 mg/day of zinc. This may be due to a zinc dose-response or to a fundamental difference in the role of zinc in the progression of early CI versus advanced AMD.
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Affiliation(s)
- Rafal Kustra
- The Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | | | | | - Brent Zanke
- Faculty of Medicine, Division of Hematology, University of Toronto, Toronto, Canada
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Arya S, Emri E, Synowsky SA, Shirran SL, Barzegar-Befroei N, Peto T, Botting CH, Lengyel I, Stewart AJ. Quantitative analysis of hydroxyapatite-binding plasma proteins in genotyped individuals with late-stage age-related macular degeneration. Exp Eye Res 2018; 172:21-29. [DOI: 10.1016/j.exer.2018.03.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 03/16/2018] [Accepted: 03/22/2018] [Indexed: 12/17/2022]
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Khan S, Birch J, Van Calsteren MR, Ipsen R, Peters GHJ, Svensson B, Harris P, Almdal K. Interaction between structurally different heteroexopolysaccharides and β-lactoglobulin studied by solution scattering and analytical ultracentrifugation. Int J Biol Macromol 2018; 111:746-754. [PMID: 29329814 DOI: 10.1016/j.ijbiomac.2018.01.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 12/24/2017] [Accepted: 01/08/2018] [Indexed: 12/28/2022]
Abstract
Despite a very large number of bacterial exopolysaccharides have been reported, detailed knowledge on their molecular structures and associative interactions with proteins is lacking. Small-angle X-ray scattering, dynamic light scattering and analytical ultracentrifugation (AUC) were used to characterize the interactions of six lactic acid bacterial heteroexopolysaccharides (HePS-1-HePS-6) with β-lactoglobulin (BLG). Compared to free HePSs, a large increase in the X-ray radius of gyration RG, maximum length L and hydrodynamic diameter dH of HePS-1-HePS-4 mixed with BLG revealed strong aggregation, the extent of which depended on the compact conformation and degree of branching of these HePSs. No significant effects were observed with HePS-5 and HePS-6. Turbidity and AUC analyses showed that both soluble and insoluble BLG-HePS complexes were formed. The findings provide new insights into the role of molecular structures in associative interactions between HePSs and BLG which has relevance for various industrial applications.
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Affiliation(s)
- Sanaullah Khan
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark; Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, Building 423, DK-2800 Kgs. Lyngby, Denmark.
| | - Johnny Birch
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Marie-Rose Van Calsteren
- Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Boulevard West, Saint-Hyacinthe, Quebec J2S 8E3, Canada
| | - Richard Ipsen
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, DK-1958 Frederiksberg, Denmark
| | - Günther H J Peters
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Pernille Harris
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Kristoffer Almdal
- Department of Micro- and Nanotechnology, Technical University of Denmark, Ørsteds Plads, Building 423, DK-2800 Kgs. Lyngby, Denmark
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van Kuijk FJ, McPherson SW, Roehrich H. Enhanced Detection of Sub-Retinal Pigment Epithelial Cell Layer Deposits in Human and Murine Tissue: Imaging Zinc as a Biomarker for Age-Related Macular Degeneration (An American Ophthalmological Society Thesis). TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 2017; 115:T3. [PMID: 29021717 PMCID: PMC5598790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
PURPOSE Understanding the apparent paradoxical role of zinc in the pathogenesis and prevention of age-related macular degeneration (AMD) has been limited by the lack of animal models for its detection in sub-retinal epithelial deposits (drusen), a definitive early hallmark of AMD. In-vitro studies using Zinpyr-1 showed drusen contained high levels of zinc, but the probe was not suitable for in-vivo studies. This study compares Zinpyr-1 to ZPP1, a new fluorescein-based probe for zinc, to assess the potential of ZPP1 for in-vivo detection of zinc in drusen. METHODS Flat mounts of human sub-RPE tissue using the probes were analyzed by fluorescence and confocal microscopy. Flat mounts of sub-RPE tissue from mice deficient in superoxide dismutase isoform-1 (CuZn-SOD-KO) or isoform-2 (Mn-SOD-RPE-KO) were analyzed with sub-RPE deposits confirmed by histology. RESULTS Drusen are detected in greater numbers and intensity with ZPP1 compared to Zinpyr-1. Using ZPP1, drusen was detected in a sample from a 46-year old human donor without ocular history, suggesting that ZPP1 might be sensitive enough to detect drusen at an early stage. With CuZn-SOD KO mice, ZPP1 detected sub-RPE deposits at 10 months of age, whereas Zinpyr-1 required 14 months. CONCLUSION Detection of sub-RPE deposits by ZPP1 was greatly enhanced compared to Zinpyr-1. This enhanced sensitivity will allow for more insightful analysis of zinc in AMD using human specimens and mouse models. This could result in the development of a sensitive in-vivo probe to enhance research on the role zinc in drusen formation and the early clinical diagnosis of AMD.
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Pilgrim MG, Lengyel I, Lanzirotti A, Newville M, Fearn S, Emri E, Knowles JC, Messinger JD, Read RW, Guidry C, Curcio CA. Subretinal Pigment Epithelial Deposition of Drusen Components Including Hydroxyapatite in a Primary Cell Culture Model. Invest Ophthalmol Vis Sci 2017; 58:708-719. [PMID: 28146236 PMCID: PMC5295770 DOI: 10.1167/iovs.16-21060] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Purpose Extracellular deposits containing hydroxyapatite, lipids, proteins, and trace metals that form between the basal lamina of the RPE and the inner collagenous layer of Bruch's membrane are hallmarks of early AMD. We examined whether cultured RPE cells could produce extracellular deposits containing all of these molecular components. Methods Retinal pigment epithelium cells isolated from freshly enucleated porcine eyes were cultured on Transwell membranes for up to 6 months. Deposit composition and structure were characterized using light, fluorescence, and electron microscopy; synchrotron x-ray diffraction and x-ray fluorescence; secondary ion mass spectroscopy; and immunohistochemistry. Results Apparently functional primary RPE cells, when cultured on 10-μm-thick inserts with 0.4-μm-diameter pores, can produce sub-RPE deposits that contain hydroxyapatite, lipids, proteins, and trace elements, without outer segment supplementation, by 12 weeks. Conclusions The data suggest that sub-RPE deposit formation is initiated, and probably regulated, by the RPE, as well as the loss of permeability of the Bruch's membrane and choriocapillaris complex associated with age and early AMD. This cell culture model of early AMD lesions provides a novel system for testing new therapeutic interventions against sub-RPE deposit formation, an event occurring well in advance of the onset of vision loss.
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Affiliation(s)
- Matthew G Pilgrim
- UCL Institute of Ophthalmology, University College London, London, United Kingdom 2Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, United Kingdom
| | - Imre Lengyel
- UCL Institute of Ophthalmology, University College London, London, United Kingdom 3Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Antonio Lanzirotti
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois, United States
| | - Matt Newville
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois, United States
| | - Sarah Fearn
- Department of Materials, Imperial College London, London, United Kingdom
| | - Eszter Emri
- UCL Institute of Ophthalmology, University College London, London, United Kingdom 3Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Jonathan C Knowles
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, United Kingdom
| | - Jeffrey D Messinger
- Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, Alabama, United States
| | - Russell W Read
- Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, Alabama, United States
| | - Clyde Guidry
- Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, Alabama, United States
| | - Christine A Curcio
- Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, Alabama, United States
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Kersten E, Paun CC, Schellevis RL, Hoyng CB, Delcourt C, Lengyel I, Peto T, Ueffing M, Klaver CCW, Dammeier S, den Hollander AI, de Jong EK. Systemic and ocular fluid compounds as potential biomarkers in age-related macular degeneration. Surv Ophthalmol 2017; 63:9-39. [PMID: 28522341 DOI: 10.1016/j.survophthal.2017.05.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 05/09/2017] [Accepted: 05/09/2017] [Indexed: 12/15/2022]
Abstract
Biomarkers can help unravel mechanisms of disease and identify new targets for therapy. They can also be useful in clinical practice for monitoring disease progression, evaluation of treatment efficacy, and risk assessment in multifactorial diseases, such as age-related macular degeneration (AMD). AMD is a highly prevalent progressive retinal disorder for which multiple genetic and environmental risk factors have been described, but the exact etiology is not yet fully understood. Many compounds have been evaluated for their association with AMD. We performed an extensive literature review of all compounds measured in serum, plasma, vitreous, aqueous humor, and urine of AMD patients. Over 3600 articles were screened, resulting in more than 100 different compounds analyzed in AMD studies, involved in neovascularization, immunity, lipid metabolism, extracellular matrix, oxidative stress, diet, hormones, and comorbidities (such as kidney disease). For each compound, we provide a short description of its function and discuss the results of the studies in relation to its usefulness as AMD biomarker. In addition, biomarkers identified by hypothesis-free techniques, including metabolomics, proteomics, and epigenomics, are covered. In summary, compounds belonging to the oxidative stress pathway, the complement system, and lipid metabolism are the most promising biomarker candidates for AMD. We hope that this comprehensive survey of the literature on systemic and ocular fluid compounds as potential biomarkers in AMD will provide a stepping stone for future research and possible implementation in clinical practice.
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Affiliation(s)
- Eveline Kersten
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Constantin C Paun
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rosa L Schellevis
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Cécile Delcourt
- Université de Bordeaux, ISPED, Bordeaux, France; INSERM, U1219-Bordeaux Population Health Research Center, Bordeaux, France
| | - Imre Lengyel
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Tunde Peto
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Marius Ueffing
- Department for Ophthalmology and Medical Bioanalytics Centre Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Caroline C W Klaver
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Sascha Dammeier
- Department for Ophthalmology and Medical Bioanalytics Centre Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Anneke I den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Eiko K de Jong
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.
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García M, Álvarez L, Fernández Á, González-Iglesias H, Escribano J, Fernández-Vega B, Villota E, Fernández-Vega Cueto L, Fernández-Vega Á, Coca-Prados M. Metallothionein polymorphisms in a Northern Spanish population with neovascular and dry forms of age-related macular degeneration. Ophthalmic Genet 2017. [PMID: 28635422 DOI: 10.1080/13816810.2017.1288825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND To elucidate the potential role of single nucleotide polymorphisms (SNPs) in the metallothionein (MT) genes in Northern Spanish patients with age-related macular degeneration (AMD). METHODS A total of 130 unrelated Northern Spanish natives diagnosed with AMD (46 dry, 35 neovascular, and 49 mixed) and 96 healthy controls, matched by age and ethnicity, were enrolled in a case-control study. DNA was isolated from peripheral blood and genotyped for 14 SNPs located at 5 MT genes (MT1A: rs11076161, rs 11640851, rs8052394, and rs7196890; MT1B: rs8052334, rs964372, and rs7191779; MT1M: rs2270836 and rs9936741; MT2A: rs28366003, rs1610216, rs10636, and rs1580833; MT3: rs45570941) using TaqMan probes. The association study was performed using the HaploView 4.0 software. RESULTS The allelic and genotypic frequencies analysis revealed that rs28366003 at MT2A gene is significantly associated with dry AMD. The frequency of genotype AG was significantly higher in dry AMD than in control cases (p = 2.65 × 10-4; AG vs. AA) conferring more than ninefold increased risk to dry AMD (OR = 9.39, 95% CI: 2.11-41.72), whereas the genotype AA confers disease protection (OR = 0.82, 95% CI: 0.71-0.95). No statistically significant differences were observed between AMD subjects and controls in the rest of the 14 SNPs analyzed. CONCLUSIONS The present study is the first to investigate the potential association of SNPs at MT genes with susceptibility to AMD. We found a significant association of SNP rs28366003 at MT2A gene with susceptibility to the dry form of AMD in a Northern Spanish population.
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Affiliation(s)
- Montserrat García
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain
| | - Lydia Álvarez
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain
| | - Ángela Fernández
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain
| | - Héctor González-Iglesias
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain
| | - Julio Escribano
- c Laboratory of Human Molecular Genetics, Faculty of Medicine/Institute of Investigation in Neurological Disabilities (IDINE) , University of Castilla-La Mancha , Albacete , Spain
| | - Beatriz Fernández-Vega
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain
| | - Eva Villota
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain
| | - Luis Fernández-Vega Cueto
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain
| | - Álvaro Fernández-Vega
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain
| | - Miguel Coca-Prados
- a Fernández-Vega University Institute, Foundation of Ophthalmological Investigation, University of Oviedo , Oviedo , Spain.,b Department of Neurodegenerative Eye Disease , Fernández-Vega Ophthalmological Institute , Oviedo , Spain.,d Department of Ophthalmology and Visual Science , Yale University School of Medicine , New Haven , Connecticut , USA
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Nutritional and Lifestyle Interventions for Age-Related Macular Degeneration: A Review. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:6469138. [PMID: 28154734 PMCID: PMC5244028 DOI: 10.1155/2017/6469138] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/02/2016] [Accepted: 12/14/2016] [Indexed: 12/16/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. In this narrative review, we will summarize the nutritional interventions evaluated in numerous observational studies and a few randomized clinical trials. The AREDS and AREDS2 studies demonstrated that supplements including vitamins C and E, beta-carotene, and zinc may reduce the progression to advanced AMD, in some patients, by 25% in five years. This is one of the few nutritional supplements known to have beneficial effects in any eye disease. Lutein/zeaxanthin supplementation may have beneficial effects in some individuals whereas omega-3 fatty acids supplementation needs to be further investigated and supported by more evidence. Genetic factors may explain the different patterns of response and explain differences found among individuals. More importantly, a combination of lifestyle behaviors such as the avoidance of smoking, physical activity, and the adoption of a healthy dietary pattern like the Mediterranean diet was associated with a lower prevalence of AMD. The adoption of these lifestyles may reduce the prevalence of the early stages of AMD and decrease the number of individuals who develop advanced AMD and consequently the onerous and climbing costs associated with the treatment of this disease.
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Khan KN, Mahroo OA, Khan RS, Mohamed MD, McKibbin M, Bird A, Michaelides M, Tufail A, Moore AT. Differentiating drusen: Drusen and drusen-like appearances associated with ageing, age-related macular degeneration, inherited eye disease and other pathological processes. Prog Retin Eye Res 2016; 53:70-106. [DOI: 10.1016/j.preteyeres.2016.04.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 04/24/2016] [Accepted: 04/27/2016] [Indexed: 12/11/2022]
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Kochounian H, Zhang Z, Spee C, Hinton DR, Fong HKW. Targeting of exon VI-skipping human RGR-opsin to the plasma membrane of pigment epithelium and co-localization with terminal complement complex C5b-9. Mol Vis 2016; 22:213-23. [PMID: 27011730 PMCID: PMC4783578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 03/01/2016] [Indexed: 10/26/2022] Open
Abstract
PURPOSE Rare mutations in the human RGR gene lead to autosomal recessive retinitis pigmentosa or dominantly inherited peripapillary choroidal atrophy. Here, we analyze a common exon-skipping isoform of the human retinal G protein-coupled receptor opsin (RGR-d) to determine differences in subcellular targeting between RGR-d and normal RGR and possible association with abnormal traits in the human eye. METHODS The terminal complement complex (C5b-9), vitronectin, CD46, syntaxin-4, and RGR-d were analyzed in human eye tissue from young and old donors or in cultured fetal RPE cells by means of immunofluorescent labeling and high-resolution confocal microscopy or immunohistochemical staining. RESULTS We observed that RGR-d is targeted to the basolateral plasma membrane of the RPE. RGR-d, but not normal RGR, is expressed in cultured human fetal RPE cells in which the protein also trafficks to the plasma membrane. In young donors, the amount of RGR-d protein in the basolateral plasma membrane was much higher than that in the RPE cells of older subjects. In older donor eyes, the level of immunoreactive RGR-d within RPE cells was often low or undetectable, and immunostaining of RGR-d was consistently strongest in extracellular deposits in Bruch's membrane. Double immunofluorescent labeling in the basal deposits revealed significant aggregate and small punctate co-localization of RGR-d with C5b-9 and vitronectin. CONCLUSIONS RGR-d may escape endoplasmic reticulum-associated degradation and in contrast to full-length RGR, traffick to the basolateral plasma membrane, particularly in younger subjects. RGR-d in the plasma membrane indicates that the protein is properly folded, as misfolded membrane proteins cannot otherwise sort to the plasma membrane. The close association of extracellular RGR-d with both vitronectin and C5b-9 suggests a potential role of RGR-d-containing deposits in complement activation.
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Affiliation(s)
| | - Zhaoxia Zhang
- Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
- USC Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - Christine Spee
- Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - David R. Hinton
- Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
- Department of Pathology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
- USC Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA
| | - Henry K. W. Fong
- Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
- Department of Molecular Microbiology and Immunology, Keck School of Medicine of the University of Southern California, Los Angeles, CA
- USC Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, CA
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Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan. Sci Rep 2016; 6:20723. [PMID: 26846575 PMCID: PMC4742947 DOI: 10.1038/srep20723] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 01/11/2016] [Indexed: 12/15/2022] Open
Abstract
This case-control study reports the association between nutrient intake and neovascular age-related macular degeneration (AMD) in Japan. The nutrient intake of 161 neovascular AMD cases from two university hospitals and 369 population-based control subjects from a cohort study was assessed using a brief-type self-administered questionnaire on diet history, which required respondent recall of the usual intake of 58 foods during the preceding month. Energy-adjusted nutrient intake values were compared between the groups. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs adjusted for smoking history, age, sex, chronic disease history, supplement use, and alcohol consumption. Logistic regression analysis demonstrated that low intakes of n-3 fatty acid, α-tocopherol, zinc, vitamin D, vitamin C, and β-carotene were associated with neovascular AMD (Trend P < 0.0001 for n-3 fatty acid, Trend P < 0.0001 for α-tocopherol, Trend P < 0.0001 for zinc, Trend P = 0.002 for vitamin D, Trend P = 0.04 for vitamin C, Trend P = 0.0004 for β-carotene). There was no association with retinol or cryptoxanthin intake and neovascular AMD (P = 0.67, 0.06).
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32
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Ma DJ, Yu HG. Nutritional supplement for age-related macular degeneration. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2016. [DOI: 10.5124/jkma.2016.59.12.955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Dae Joong Ma
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
| | - Hyeong Gon Yu
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea
- Retinal Degeneration Research Lab, Seoul National University Hospital Biomedical Research Institute, Seoul, Korea
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Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites. Biochem J 2015; 473:43-54. [PMID: 26487699 DOI: 10.1042/bj20150836] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/20/2015] [Indexed: 02/07/2023]
Abstract
Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.
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Schmidl D, Garhöfer G, Schmetterer L. Nutritional supplements in age-related macular degeneration. Acta Ophthalmol 2015; 93:105-21. [PMID: 25586104 DOI: 10.1111/aos.12650] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 11/28/2014] [Indexed: 12/22/2022]
Abstract
Age-related macular degeneration (AMD) is the most frequent cause of blindness in the Western World. While with new therapies that are directed towards vascular endothelial growth factor (VEGF), a potentially efficient treatment option for the wet form of the disease has been introduced, a therapeutic regimen for dry AMD is still lacking. There is evidence from several studies that oral intake of supplements is beneficial in preventing progression of the disease. Several formulations of micronutrients are currently available. The present review focuses on the role of supplements in the treatment and prevention of AMD and sums up the current knowledge about the most frequently used micronutrients. In addition, regulatory issues are discussed, and future directions for the role of supplementation in AMD are highlighted.
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Affiliation(s)
- Doreen Schmidl
- Department of Clinical Pharmacology; Medical University of Vienna; Vienna Austria
| | - Gerhard Garhöfer
- Department of Clinical Pharmacology; Medical University of Vienna; Vienna Austria
| | - Leopold Schmetterer
- Department of Clinical Pharmacology; Medical University of Vienna; Vienna Austria
- Center for Medical Physics and Biomedical Engineering; Medical University of Vienna; Vienna Austria
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35
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Flinn JM, Kakalec P, Tappero R, Jones B, Lengyel I. Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration. Metallomics 2015; 6:1223-8. [PMID: 24740686 DOI: 10.1039/c4mt00058g] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.
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Affiliation(s)
- Jane M Flinn
- Psychology, George Mason University, Fairfax, VA, USA
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36
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Zinc supplementation inhibits complement activation in age-related macular degeneration. PLoS One 2014; 9:e112682. [PMID: 25393287 PMCID: PMC4231060 DOI: 10.1371/journal.pone.0112682] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 10/06/2014] [Indexed: 11/19/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. AMD is a multifactorial disorder but complement-mediated inflammation at the level of the retina plays a pivotal role. Oral zinc supplementation can reduce the progression of AMD but the precise mechanism of this protective effect is as yet unclear. We investigated whether zinc supplementation directly affects the degree of complement activation in AMD and whether there is a relation between serum complement catabolism during zinc administration and the complement factor H (CFH) gene or the Age-Related Maculopathy susceptibility 2 (ARMS2) genotype. In this open-label clinical study, 72 randomly selected AMD patients in various stages of AMD received a daily supplement of 50 mg zinc sulphate and 1 mg cupric sulphate for three months. Serum complement catabolism–defined as the C3d/C3 ratio–was measured at baseline, throughout the three months of supplementation and after discontinuation of zinc administration. Additionally, downstream inhibition of complement catabolism was evaluated by measurement of anaphylatoxin C5a. Furthermore, we investigated the effect of zinc on complement activation in vitro. AMD patients with high levels of complement catabolism at baseline exhibited a steeper decline in serum complement activation (p<0.001) during the three month zinc supplementation period compared to patients with low complement levels. There was no significant association of change in complement catabolism and CFH and ARMS2 genotype. In vitro zinc sulphate directly inhibits complement catabolism in hemolytic assays and membrane attack complex (MAC) deposition on RPE cells. This study provides evidence that daily administration of 50 mg zinc sulphate can inhibit complement catabolism in AMD patients with increased complement activation. This could explain part of the mechanism by which zinc slows AMD progression. Trial Registration The Netherlands National Trial Register NTR2605
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Perkins SJ, Fung KW, Khan S. Molecular Interactions between Complement Factor H and Its Heparin and Heparan Sulfate Ligands. Front Immunol 2014; 5:126. [PMID: 24744754 PMCID: PMC3978290 DOI: 10.3389/fimmu.2014.00126] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 03/12/2013] [Indexed: 11/13/2022] Open
Abstract
Complement factor H (CFH) is the major regulator of the central complement protein C3b in the alternative pathway of complement activation. A molecular view of the CFH interaction with native heparan sulfate (HS) is central for understanding the mechanism of how surface-bound CFH interacts with C3b bound to host cell surfaces. HS is composed of sulfated heparin-like S-regions that alternate with desulfated NA-regions. Solution structural studies of heparin (equivalent to the S-regions) and desulfated HS (the NA-regions) by scattering and ultracentrifugation showed that each structure was mostly extended and partially bent, but with greater bending and flexibility in the NA-regions compared to the S-regions. Their solution structures have been deposited in the Protein Data Bank. The largest HS oligosaccharides showed more bent and flexible structures than those for heparin. A folded-back domain structure for the solution structure of the 20 domains in CFH was determined likewise. CFH binds to the S-regions but less so to the NA-regions of HS. The bivalent interaction of CFH–heparin was observed by ultracentrifugation, and binding studies of CFH fragments with heparin-coated sensor chips. In common with other CFH interactions with its physiological and pathophysiological ligands, the CFH–heparin and CFH–C3b interactions have moderate micromolar dissociation constants KD, meaning that these complexes do not fully form in vivo. The combination of the solution structures and binding studies indicated a two-site interaction model of CFH with heparin at cell surfaces. By this, the bivalent binding of CFH to a cell surface is co-operative. Defective interactions at either of the two independent CFH–heparin sites reduce the CFH interaction with surface-bound C3b and lead to immune disorders.
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Affiliation(s)
- Stephen J Perkins
- Department of Structural and Molecular Biology, University College London , London , UK
| | - Ka Wai Fung
- Department of Structural and Molecular Biology, University College London , London , UK
| | - Sanaullah Khan
- Department of Structural and Molecular Biology, University College London , London , UK
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Kumar AA, Hati D, Thaker TM, Miah L, Cunningham P, Domene C, Bui TTT, Drake AF, McDermott LC. Strong and weak zinc binding sites in human zinc-α2-glycoprotein. FEBS Lett 2013; 587:3949-54. [PMID: 24188824 DOI: 10.1016/j.febslet.2013.10.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 10/22/2013] [Indexed: 11/24/2022]
Abstract
Zinc-α2-glycoprotein (ZAG) is an adipokine with an MHC class I-like protein fold. Even though zinc causes ZAG to precipitate from plasma during protein purification, no zinc binding has been identified to date. Using mass spectrometry, we demonstrated that ZAG contains one strongly bound zinc ion, predicted to lie close to the α1 and α2 helical groove. UV, CD and fluorescence spectroscopies detected weak zinc binding to holo-ZAG, which can bind up to 15 zinc ions. Zinc binding to 11-(dansylamino) undecanoic acid was enhanced by holo-ZAG. Zinc binding may be important for ZAG binding to fatty acids and the β-adrenergic receptor.
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Affiliation(s)
- Aditya Arun Kumar
- Department of Biochemistry, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
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