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Xu W, Xie B, Wei D, Song X. Dissecting hair breakage in alopecia areata: the central role of dysregulated cysteine homeostasis. Amino Acids 2024; 56:36. [PMID: 38772922 PMCID: PMC11108903 DOI: 10.1007/s00726-024-03395-5] [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: 01/07/2024] [Accepted: 04/16/2024] [Indexed: 05/23/2024]
Abstract
In the initial stages of Alopecia Areata (AA), the predominance of hair breakage or exclamation mark hairs serves as vital indicators of disease activity. These signs are non-invasive and are commonly employed in dermatoscopic examinations. Despite their clinical salience, the underlying etiology precipitating this hair breakage remains largely uncharted territory. Our exhaustive review of the existing literature points to a pivotal role for cysteine-a key amino acid central to hair growth-in these mechanisms. This review will probe and deliberate upon the implications of aberrant cysteine metabolism in the pathogenesis of AA. It will examine the potential intersections of cysteine metabolism with autophagy, ferroptosis, immunity, and psychiatric manifestations associated with AA. Such exploration could illuminate new facets of the disease's pathophysiology, potentially paving the way for innovative therapeutic strategies.
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Affiliation(s)
- Wen Xu
- School of Medicine, Zhejiang University, Yuhangtang Rd 866, Hangzhou, 310009, People's Republic of China
- Department of Dermatology, Hangzhou Third People's Hospital, Affiliated Hangzhou Dermatology Hospital, Zhejiang University School of Medicine, Hangzhou Third Hospital, Affiliated to Zhejiang Chinese Medical University, West Lake Ave 38, Hangzhou, 310009, People's Republic of China
| | - Bo Xie
- Department of Dermatology, Hangzhou Third People's Hospital, Affiliated Hangzhou Dermatology Hospital, Zhejiang University School of Medicine, Hangzhou Third Hospital, Affiliated to Zhejiang Chinese Medical University, West Lake Ave 38, Hangzhou, 310009, People's Republic of China
| | - Dongfan Wei
- School of Medicine, Zhejiang University, Yuhangtang Rd 866, Hangzhou, 310009, People's Republic of China
- Department of Dermatology, Hangzhou Third People's Hospital, Affiliated Hangzhou Dermatology Hospital, Zhejiang University School of Medicine, Hangzhou Third Hospital, Affiliated to Zhejiang Chinese Medical University, West Lake Ave 38, Hangzhou, 310009, People's Republic of China
| | - Xiuzu Song
- Department of Dermatology, Hangzhou Third People's Hospital, Affiliated Hangzhou Dermatology Hospital, Zhejiang University School of Medicine, Hangzhou Third Hospital, Affiliated to Zhejiang Chinese Medical University, West Lake Ave 38, Hangzhou, 310009, People's Republic of China.
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Álvarez-Barrios A, Álvarez L, Pereiro R, González-Iglesias H. Elemental mass spectrometry to study metallo-transcriptomic changes during the in vitro degeneration of the retinal pigment epithelium. Anal Bioanal Chem 2024; 416:2699-2710. [PMID: 37507467 PMCID: PMC11009741 DOI: 10.1007/s00216-023-04880-8] [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: 06/05/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
Trace elements play crucial roles in cellular biology. Their improper homeostasis may contribute to the progress of eye diseases, exacerbated during ageing. The retinal pigment epithelium (RPE) is progressively deteriorated during age-related neurodegeneration and metal homeostasis may be compromised. In this study, elemental mass spectrometry (MS) was combined with cellular and molecular biology techniques to identify changes in trace elements during the in vitro degeneration of human RPE cells. Cells were collected at 21, 91, and 133 days and processed for RNA sequencing; Ca, Na, P, Mg, and Cu quantification by flow injection analysis and inductively coupled plasma-MS; and protein analysis by immunocytochemistry. Four-month-old RPE cultures showed depigmentation, impaired barrier function, and antioxidant protection, manifesting signs of epithelial-to-mesenchymal transition. Na and P significantly increased in the cytosol of degenerated RPE cells (from 15 ± 20 to 13495 ± 638 ng·µg-1 and from 30.6 ± 9.5 to 116.8 ± 16.8 ng·µg-1, respectively). Mg decreased in both the cytosol and insoluble fraction of cells (from 2.83 ± 0.40 to 1.58 ± 0.56 ng·µg-1 and from 247.57 ± 11.06 to 30 ± 8 ng·g-1, respectively), while P and Cu decreased in the insoluble fraction after 133 days in culture (from 9471 ± 1249 to 4555 ± 985 ng·µg-1 and from 2251 ± 79 to 1054 ± 235 ng·g-1, respectively), along with changes in metal-dependent antioxidant enzymes and Cu transporters. This RPE model reflected metal homeostatic changes, providing additional perspectives on effects of metal regulation during ageing.
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Affiliation(s)
- Ana Álvarez-Barrios
- Fundación de Investigación Oftalmológica, Avda. Dres. Fernández-Vega. 34, 33012, Oviedo, Spain
- Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
| | - Lydia Álvarez
- Fundación de Investigación Oftalmológica, Avda. Dres. Fernández-Vega. 34, 33012, Oviedo, Spain.
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012, Oviedo, Spain.
| | - Rosario Pereiro
- Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Villaviciosa, Spain.
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Liu C, Tang J, Chen Y, Zhang Q, Lin J, Wu S, Han J, Liu Z, Wu C, Zhuo Y, Li Y. Intracellular Zn 2+ promotes extracellular matrix remodeling in dexamethasone-treated trabecular meshwork. Am J Physiol Cell Physiol 2024; 326:C1293-C1307. [PMID: 38525543 DOI: 10.1152/ajpcell.00725.2023] [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: 12/31/2023] [Revised: 02/26/2024] [Accepted: 03/09/2024] [Indexed: 03/26/2024]
Abstract
Given the widespread application of glucocorticoids in ophthalmology, the associated elevation of intraocular pressure (IOP) has long been a vexing concern for clinicians, yet the underlying mechanisms remain inconclusive. Much of the discussion focuses on the extracellular matrix (ECM) of trabecular meshwork (TM). It is widely agreed that glucocorticoids impact the expression of matrix metalloproteinases (MMPs), leading to ECM deposition. Since Zn2+ is vital for MMPs, we explored its role in ECM alterations induced by dexamethasone (DEX). Our study revealed that in human TM cells treated with DEX, the level of intracellular Zn2+ significantly decreased, accompanied by impaired extracellular Zn2+ uptake. This correlated with changes in several Zrt-, Irt-related proteins (ZIPs) and metallothionein. ZIP8 knockdown impaired extracellular Zn2+ uptake, but Zn2+ chelation did not affect ZIP8 expression. Resembling DEX's effects, chelation of Zn2+ decreased MMP2 expression, increased the deposition of ECM proteins, and induced structural disarray of ECM. Conversely, supplementation of exogenous Zn2+ in DEX-treated cells ameliorated these outcomes. Notably, dietary zinc supplementation in mice significantly reduced DEX-induced IOP elevation and collagen content in TM, thereby rescuing the visual function of the mice. These findings underscore zinc's pivotal role in ECM regulation, providing a novel perspective on the pathogenesis of glaucoma.NEW & NOTEWORTHY Our study explores zinc's pivotal role in mitigating extracellular matrix dysregulation in the trabecular meshwork and glucocorticoid-induced ocular hypertension. We found that in human trabecular meshwork cells treated with dexamethasone, intracellular Zn2+ significantly decreased, accompanied by impaired extracellular Zn2+ uptake. Zinc supplementation rescues visual function by modulating extracellular matrix proteins and lowering intraocular pressure, offering a direction for further exploration in glaucoma management.
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Affiliation(s)
- Canying Liu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Jiahui Tang
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Yuze Chen
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Qi Zhang
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Jicheng Lin
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Siting Wu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Jiaxu Han
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Zhe Liu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Caiqing Wu
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Yehong Zhuo
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
| | - Yiqing Li
- State Key Laboratory of OphthalmologyZhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouChina
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Zuo Z, Pang W, Sun W, Lu B, Zou L, Zhang D, Wang Y. Metallothionein-Kidney Bean Polyphenol Complexes Showed Antidiabetic Activity in Type 2 Diabetic Rats by Improving Insulin Resistance and Regulating Gut Microbiota. Foods 2023; 12:3139. [PMID: 37628138 PMCID: PMC10453533 DOI: 10.3390/foods12163139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Previous studies have shown that interaction between polyphenols and proteins can benefit health, but the mechanism of its antidiabetic effect has not been thoroughly elucidated. Therefore, this study aimed to investigate the impact of the metallothionein (MT)-kidney bean polyphenol complex on the blood glucose levels and gut microbiota of rats with type 2 diabetes mellitus (T2DM) induced by a high-fat diet combined with streptozotocin (STZ). After 7 weeks of intervention, the MT-kidney bean polyphenol complex can significantly improve the loss of body weight, the increase in blood glucose and blood lipids, and insulin resistance caused by T2DM in rats. In addition, it can effectively alleviate the damage to the pancreas and liver in rats. The MT-kidney bean polyphenol complex also significantly increased the concentrations of six short-chain fatty acids (SCFAs) in the intestinal contents of rats, especially acetic acid, propionic acid, and butyric acid (296.03%, 223.86%, and 148.97%, respectively). More importantly, the MT-kidney bean polyphenol complex can significantly reverse intestinal microflora dysbiosis in rats caused by T2DM, increase intestinal microorganism diversity, improve the abundance of various beneficial bacteria, and reshape the gut microbiota. In summary, the hypoglycemic effect of the MT-kidney bean polyphenol complex and its possible mechanism was expounded in terms of blood glucose level, blood lipid level, and gut microbiota, providing a new perspective on the development of the MT-kidney bean polyphenol complex as functional hypoglycemic food.
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Affiliation(s)
- Zhaohang Zuo
- College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (Z.Z.); (W.P.); (W.S.); (D.Z.)
| | - Weiqiao Pang
- College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (Z.Z.); (W.P.); (W.S.); (D.Z.)
| | - Wei Sun
- College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (Z.Z.); (W.P.); (W.S.); (D.Z.)
| | - Baoxin Lu
- College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (Z.Z.); (W.P.); (W.S.); (D.Z.)
| | - Liang Zou
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering & Technology Research Center of Coarse Cereal Industralization, School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China;
| | - Dongjie Zhang
- College of Food Science, Heilongjiang Bayi Agricultural University, Daqing 163319, China; (Z.Z.); (W.P.); (W.S.); (D.Z.)
- National Coarse Cereals Engineering Research Center, Daqing 163319, China
| | - Ying Wang
- National Coarse Cereals Engineering Research Center, Daqing 163319, China
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Jamrozik D, Dutczak R, Machowicz J, Wojtyniak A, Smędowski A, Pietrucha-Dutczak M. Metallothioneins, a Part of the Retinal Endogenous Protective System in Various Ocular Diseases. Antioxidants (Basel) 2023; 12:1251. [PMID: 37371981 DOI: 10.3390/antiox12061251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/01/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Metallothioneins are the metal-rich proteins that play important roles in metal homeostasis and detoxification. Moreover, these proteins protect cells against oxidative stress, inhibit proapoptotic mechanisms and enhance cell differentiation and survival. Furthermore, MTs, mainly MT-1/2 and MT-3, play a vital role in protecting the neuronal retinal cells in the eye. Expression disorders of these proteins may be responsible for the development of various age-related eye diseases, including glaucoma, age-related macular degeneration, diabetic retinopathy and retinitis pigmentosa. In this review, we focused on the literature reports suggesting that these proteins may be a key component of the endogenous protection system of the retinal neurons, and, when the expression of MTs is disrupted, this system becomes inefficient. Moreover, we described the location of different MT isoforms in ocular tissues. Then we discussed the changes in MT subtypes' expression in the context of the common eye diseases. Finally, we highlighted the possibility of the use of MTs as biomarkers for cancer diagnosis.
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Affiliation(s)
- Daniel Jamrozik
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
| | - Radosław Dutczak
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
| | - Joanna Machowicz
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
| | - Alicja Wojtyniak
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
| | - Adrian Smędowski
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
- GlaucoTech Co., Gen., Władysława Sikorskiego 45/177, 40-282 Katowice, Poland
| | - Marita Pietrucha-Dutczak
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18, 40-752 Katowice, Poland
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The Role of Selected Trace Elements in Oxidoreductive Homeostasis in Patients with Thyroid Diseases. Int J Mol Sci 2023; 24:ijms24054840. [PMID: 36902266 PMCID: PMC10003705 DOI: 10.3390/ijms24054840] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/26/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
Impaired levels of selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn) and iodine (I) in the organism may adversely affect the thyroid endocrine system. These trace elements play a role in the fight against oxidative stress as components of enzymes. Oxidative-antioxidant imbalance is considered a possible factor in many pathological conditions, including various thyroid diseases. In the available literature, there are few scientific studies showing a direct correlation of the effect of supplementation of trace elements on slowing down or preventing the occurrence of thyroid diseases in combination with the improvement of the antioxidant profile, or through the action of these elements as antioxidants. Among the available studies, it has been shown that an increase in lipid peroxidation levels and a decrease in the overall antioxidant defense status occur during such thyroid diseases as thyroid cancer, Hashimoto's thyroiditis and dysthyroidism. In studies in which trace elements were supplemented, the following were observed: a decrease in the level of malondialdehyde after supplementation with Zn during hypothyroidism and reduction in the malondialdehyde level after Se supplementation with a simultaneous increase in the total activity status and activity of antioxidant defense enzymes in the course of autoimmune thyroiditis. This systematic review aimed to present the current state of knowledge about the relationship between trace elements and thyroid diseases in terms of oxidoreductive homeostasis.
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Pacwa A, Machowicz J, Akhtar S, Rodak P, Liu X, Pietrucha-Dutczak M, Lewin-Kowalik J, Amadio M, Smedowski A. Deficiency of the RNA-binding protein ELAVL1/HuR leads to the failure of endogenous and exogenous neuroprotection of retinal ganglion cells. Front Cell Neurosci 2023; 17:1131356. [PMID: 36874215 PMCID: PMC9982123 DOI: 10.3389/fncel.2023.1131356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 02/06/2023] [Indexed: 02/19/2023] Open
Abstract
Introduction ELAVL1/HuR is a keystone regulator of gene expression at the posttranscriptional level, including stress response and homeostasis maintenance. The aim of this study was to evaluate the impact of hur silencing on the age-related degeneration of retinal ganglion cells (RGC), which potentially describes the efficiency of endogenous neuroprotection mechanisms, as well as to assess the exogenous neuroprotection capacity of hur-silenced RGC in the rat glaucoma model. Methods The study consisted of in vitro and in vivo approaches. In vitro, we used rat B-35 cells to investigate, whether AAV-shRNA-HuR delivery affects survival and oxidative stress markers under temperature and excitotoxic insults. In vivo approach consisted of two different settings. In first one, 35 eight-week-old rats received intravitreal injection of AAV-shRNA-HuR or AAV-shRNA scramble control. Animals underwent electroretinography tests and were sacrificed 2, 4 or 6 months after injection. Retinas and optic nerves were collected and processed for immunostainings, electron microscopy and stereology. For the second approach, animals received similar gene constructs. To induce chronic glaucoma, 8 weeks after AAV injection, unilateral episcleral vein cauterization was performed. Animals from each group received intravitreal injection of metallothionein II. Animals underwent electroretinography tests and were sacrificed 8 weeks later. Retinas and optic nerves were collected and processed for immunostainings, electron microscopy and stereology. Results Silencing of hur induced apoptosis and increased oxidative stress markers in B-35 cells. Additionally, shRNA treatment impaired the cellular stress response to temperature and excitotoxic insults. In vivo, RGC count was decreased by 39% in shRNA-HuR group 6 months after injection, when compared to shRNA scramble control group. In neuroprotection study, the average loss of RGCs was 35% in animals with glaucoma treated with metallothionein and shRNA-HuR and 11.4% in animals with glaucoma treated with metallothionein and the scramble control shRNA. An alteration in HuR cellular content resulted in diminished photopic negative responses in the electroretinogram. Conclusions Based on our findings, we conclude that HuR is essential for the survival and efficient neuroprotection of RGC and that the induced alteration in HuR content accelerates both the age-related and glaucoma-induced decline in RGC number and function, further confirming HuR's key role in maintaining cell homeostasis and its possible involvement in the pathogenesis of glaucoma.
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Affiliation(s)
- Anna Pacwa
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland.,GlaucoTech Co., Katowice, Poland
| | - Joanna Machowicz
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland
| | - Saeed Akhtar
- College of Applied Medical Sciences, Inaya Medical Colleges, Riyadh, Saudi Arabia.,Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Piotr Rodak
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland
| | - Xiaonan Liu
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland.,Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Marita Pietrucha-Dutczak
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland
| | - Joanna Lewin-Kowalik
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland.,GlaucoTech Co., Katowice, Poland
| | - Marialaura Amadio
- Department of Drug Sciences, Section of Pharmacology, The University of Pavia, Pavia, Italy
| | - Adrian Smedowski
- Department of Physiology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland.,GlaucoTech Co., Katowice, Poland
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Álvarez-Barrios A, Álvarez L, Artime E, García M, Lengyel I, Pereiro R, González-Iglesias H. Altered zinc homeostasis in a primary cell culture model of the retinal pigment epithelium. Front Nutr 2023; 10:1124987. [PMID: 37139441 PMCID: PMC10149808 DOI: 10.3389/fnut.2023.1124987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/22/2023] [Indexed: 05/05/2023] Open
Abstract
The retinal pigment epithelium (RPE) is progressively degenerated during age-related macular degeneration (AMD), one of the leading causes of irreversible blindness, which clinical hallmark is the buildup of sub-RPE extracellular material. Clinical observations indicate that Zn dyshomeostasis can initiate detrimental intracellular events in the RPE. In this study, we used a primary human fetal RPE cell culture model producing sub-RPE deposits accumulation that recapitulates features of early AMD to study Zn homeostasis and metalloproteins changes. RPE cell derived samples were collected at 10, 21 and 59 days in culture and processed for RNA sequencing, elemental mass spectrometry and the abundance and cellular localization of specific proteins. RPE cells developed processes normal to RPE, including intercellular unions formation and expression of RPE proteins. Punctate deposition of apolipoprotein E, marker of sub-RPE material accumulation, was observed from 3 weeks with profusion after 2 months in culture. Zn cytoplasmic concentrations significantly decreased 0.2 times at 59 days, from 0.264 ± 0.119 ng·μg-1 at 10 days to 0.062 ± 0.043 ng·μg-1 at 59 days (p < 0.05). Conversely, increased levels of Cu (1.5-fold in cytoplasm, 5.0-fold in cell nuclei and membranes), Na (3.5-fold in cytoplasm, 14.0-fold in cell nuclei and membranes) and K (6.8-fold in cytoplasm) were detected after 59-days long culture. The Zn-regulating proteins metallothioneins showed significant changes in gene expression over time, with a potent down-regulation at RNA and protein level of the most abundant isoform in primary RPE cells, from 0.141 ± 0.016 ng·mL-1 at 10 days to 0.056 ± 0.023 ng·mL-1 at 59 days (0.4-fold change, p < 0.05). Zn influx and efflux transporters were also deregulated, along with an increase in oxidative stress and alterations in the expression of antioxidant enzymes, including superoxide dismutase, catalase and glutathione peroxidase. The RPE cell model producing early accumulation of extracellular deposits provided evidences on an altered Zn homeostasis, exacerbated by changes in cytosolic Zn-binding proteins and Zn transporters, along with variations in other metals and metalloproteins, suggesting a potential role of altered Zn homeostasis during AMD development.
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Affiliation(s)
- Ana Álvarez-Barrios
- Fundación de Investigación Oftalmológica, Oviedo, Spain
- Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería, 8, Oviedo, Spain
| | - Lydia Álvarez
- Fundación de Investigación Oftalmológica, Oviedo, Spain
- Lydia Álvarez,
| | - Enol Artime
- Fundación de Investigación Oftalmológica, Oviedo, Spain
| | | | - Imre Lengyel
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen’s University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Rosario Pereiro
- Department of Physical and Analytical Chemistry, University of Oviedo, Julián Clavería, 8, Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto de Productos Lácteos de Asturias, Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Villaviciosa, Spain
- *Correspondence: Héctor González-Iglesias,
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Sim EZ, Enomoto T, Shiraki N, Furuta N, Kashio S, Kambe T, Tsuyama T, Arakawa A, Ozawa H, Yokoyama M, Miura M, Kume S. Methionine metabolism regulates pluripotent stem cell pluripotency and differentiation through zinc mobilization. Cell Rep 2022; 40:111120. [PMID: 35858556 DOI: 10.1016/j.celrep.2022.111120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 04/19/2022] [Accepted: 06/28/2022] [Indexed: 11/03/2022] Open
Abstract
Pluripotent stem cells (PSCs) exhibit a unique feature that requires S-adenosylmethionine (SAM) for the maintenance of their pluripotency. Methionine deprivation in the medium causes a reduction in intracellular SAM, thus rendering PSCs in a state potentiated for differentiation. In this study, we find that methionine deprivation triggers a reduction in intracellular protein-bound Zn content and upregulation of Zn exporter SLC30A1 in PSCs. Culturing PSCs in Zn-deprived medium results in decreased intracellular protein-bound Zn content, reduced cell growth, and potentiated differentiation, which partially mimics methionine deprivation. PSCs cultured under Zn deprivation exhibit an altered methionine metabolism-related metabolite profile. We conclude that methionine deprivation potentiates differentiation partly by lowering cellular Zn content. We establish a protocol to generate functional pancreatic β cells by applying methionine and Zn deprivation. Our results reveal a link between Zn signaling and methionine metabolism in the regulation of cell fate in PSCs.
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Affiliation(s)
- Erinn Zixuan Sim
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-25 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Takayuki Enomoto
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-25 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Nobuaki Shiraki
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-25 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
| | - Nao Furuta
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-25 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Soshiro Kashio
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Taiho Kambe
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Tomonori Tsuyama
- Division of Stem Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Akihiro Arakawa
- Research Institute for Bioscience Products and Fine Chemicals, Ajinomoto, Kawasaki-shi, Kanagawa, Japan
| | - Hiroki Ozawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-25 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan
| | - Mizuho Yokoyama
- Research Institute for Bioscience Products and Fine Chemicals, Ajinomoto, Kawasaki-shi, Kanagawa, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shoen Kume
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-25 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
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10
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Ruiss M, Findl O, Kronschläger M. The human lens: An antioxidant-dependent tissue revealed by the role of caffeine. Ageing Res Rev 2022; 79:101664. [PMID: 35690384 DOI: 10.1016/j.arr.2022.101664] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/24/2022] [Accepted: 06/04/2022] [Indexed: 11/01/2022]
Abstract
Cataract is the leading cause of blindness worldwide and surgery is the only option to treat the disease. Although the surgery is considered to be relatively safe, complications may occur in a subset of patients and access to ophthalmic care may be limited. Due to a growing and ageing population, an increase in cataract prevalence is expected and its management will become a socioeconomic challenge. Hence, there is a need for an alternative to cataract surgery. It is well known that oxidative stress is one of the main pathological processes leading to the generation of the disease. Antioxidant supplementation may, therefore, be a strategy to delay or to prevent the progression of cataract. Caffeine is a widely consumed high-potency antioxidant and may be of interest for the prevention of the disease. This review aims to give an overview of the anatomy and function of the lens, its antioxidant and reactive oxygen species (ROS) composition, and the role of oxidative stress in cataractogenesis. Also, the pharmacokinetics and -dynamics of caffeine will be described and the literature will be reviewed to give an overview of its anti-cataract potential and its possible role in the prevention of the disease.
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Affiliation(s)
- Manuel Ruiss
- Vienna Institute for Research in Ocular Surgery (VIROS), a Karl Landsteiner Institute, Department of Ophthalmology, Hanusch Hospital, Vienna 1140 Austria.
| | - Oliver Findl
- Vienna Institute for Research in Ocular Surgery (VIROS), a Karl Landsteiner Institute, Department of Ophthalmology, Hanusch Hospital, Vienna 1140 Austria.
| | - Martin Kronschläger
- Vienna Institute for Research in Ocular Surgery (VIROS), a Karl Landsteiner Institute, Department of Ophthalmology, Hanusch Hospital, Vienna 1140 Austria.
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11
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Valencia E, García M, Fernández-Vega B, Pereiro R, Lobo L, González-Iglesias H. Targeted Analysis of Tears Revealed Specific Altered Metal Homeostasis in Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2022; 63:10. [PMID: 35426907 PMCID: PMC9034717 DOI: 10.1167/iovs.63.4.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose Specific altered metal homeostasis has been investigated in the tear film of age-related macular degeneration (AMD) patients considering that metal dyshomeostasis contributes to the production of free radicals, inflammation, and apoptosis and results in conformational changes of proteins. Methods A multitargeted approach based on spectrophotometry and mass spectrometry techniques has been implemented to the multiplexed quantitation of lactoferrin (LF), S100 calcium binding protein A6 (S100A6), metallothionein 1A (MT1A), complement factor H (CFH), clusterin (CLU), amyloid precursor protein (APP), Mg, P, Na, Fe, Cu, Zn, and Ca, in the tear film from 60 subjects, 31 patients diagnosed with the dry form of AMD, and 29 healthy individuals Results Significant up-regulations of MT1A (1.9-fold) and S100A6 (1.4-fold) and down-regulations of LF (0.7-fold), Fe (0.6-fold), Mg (0.7-fold), and Cu (0.7-fold) were observed in AMD patients, when compared to control subjects. Of all the studied variables, only APP showed negative correlation with age in the AMD group. Also, positive correlations were observed for the variables Mg and Na, Cu and Mg, and P and Mg in both the AMD and control groups, whereas positive correlations were exclusively determined in the AMD group for Cu and LF, Na and Ca, and Mg and Ca. The panel constituted of MT1A, Na, and Mg predicts AMD disease in 73% of cases. Conclusions The different levels of target metals and (metallo-)proteins in the tear film suggest altered metal homeostasis in AMD patients. These observed pathophysiological changes may be related with the anomalous protein aggregation in the macula.
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Affiliation(s)
- Eva Valencia
- Ophtalmological Research Foundation, University Institute Fernández-Vega, University of Oviedo, Oviedo, Spain.,Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Oviedo, Spain
| | - Montserrat García
- Ophtalmological Research Foundation, University Institute Fernández-Vega, University of Oviedo, Oviedo, Spain.,Ophthalmological Institute Fernández-Vega, Oviedo, Spain
| | - Beatriz Fernández-Vega
- Ophtalmological Research Foundation, University Institute Fernández-Vega, University of Oviedo, Oviedo, Spain.,Ophthalmological Institute Fernández-Vega, Oviedo, Spain
| | - Rosario Pereiro
- Ophtalmological Research Foundation, University Institute Fernández-Vega, University of Oviedo, Oviedo, Spain.,Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Oviedo, Spain
| | - Lara Lobo
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Oviedo, Spain
| | - Héctor González-Iglesias
- Ophtalmological Research Foundation, University Institute Fernández-Vega, University of Oviedo, Oviedo, Spain.,Ophthalmological Institute Fernández-Vega, Oviedo, Spain
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12
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Fasae KD, Abolaji AO, Faloye TR, Odunsi AY, Oyetayo BO, Enya JI, Rotimi JA, Akinyemi RO, Whitworth AJ, Aschner M. Metallobiology and therapeutic chelation of biometals (copper, zinc and iron) in Alzheimer's disease: Limitations, and current and future perspectives. J Trace Elem Med Biol 2021; 67:126779. [PMID: 34034029 DOI: 10.1016/j.jtemb.2021.126779] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 04/03/2021] [Accepted: 05/10/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) is the most prevalent cause of cognitive impairment and dementia worldwide. The pathobiology of the disease has been studied in the form of several hypotheses, ranging from oxidative stress, amyloid-beta (Aβ) aggregation, accumulation of tau forming neurofibrillary tangles (NFT) through metal dysregulation and homeostasis, dysfunction of the cholinergic system, and to inflammatory and autophagic mechanism. However, none of these hypotheses has led to confirmed diagnostics or approved cure for the disease. OBJECTIVE This review is aimed as a basic and an encyclopedic short course into metals in AD and discusses the advances in chelation strategies and developments adopted in the treatment of the disease. Since there is accumulating evidence of the role of both biometal dyshomeostasis (iron (Fe), copper (Cu), and zinc (Zn)) and metal-amyloid interactions that lead to the pathogenesis of AD, this review focuses on unraveling therapeutic chelation strategies that have been considered in the treatment of the disease, aiming to sequester free and protein-bound metal ions and reducing cerebral metal burden. Promising compounds possessing chemically modified moieties evolving as multi-target ligands used as anti-AD drug candidates are also covered. RESULTS AND CONCLUSION Several multidirectional and multifaceted studies on metal chelation therapeutics show the need for improved synthesis, screening, and analysis of compounds to be able to effectively present chelating anti-AD drugs. Most drug candidates studied have limitations in their physicochemical properties; some enhance redistribution of metal ions, while others indirectly activate signaling pathways in AD. The metal chelation process in vivo still needs to be established and the design of potential anti-AD compounds that bi-functionally sequester metal ions as well as inhibit the Aβ aggregation by competing with the metal ions and reducing metal-induced oxidative damage and neurotoxicity may signal a bright end in chelation-based therapeutics of AD.
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Affiliation(s)
- Kehinde D Fasae
- Department of Biochemistry, Molecular Drug Metabolism and Toxicology Unit, College of Medicine, University of Ibadan, Nigeria
| | - Amos O Abolaji
- Department of Biochemistry, Molecular Drug Metabolism and Toxicology Unit, College of Medicine, University of Ibadan, Nigeria.
| | - Tolulope R Faloye
- Department of Biochemistry, Molecular Drug Metabolism and Toxicology Unit, College of Medicine, University of Ibadan, Nigeria
| | - Atinuke Y Odunsi
- Department of Biochemistry, Molecular Drug Metabolism and Toxicology Unit, College of Medicine, University of Ibadan, Nigeria
| | - Bolaji O Oyetayo
- Department of Pharmacology and Therapeutics, Neuropharmacology Unit, College of Medicine, University of Ibadan, Nigeria
| | - Joseph I Enya
- Department of Anatomy, University of Ilorin, Kwara State, Nigeria
| | - Joshua A Rotimi
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria
| | - Rufus O Akinyemi
- Neuroscience and Ageing Research Unit, Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | | | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.
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13
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Kador PF, Salvi R. Multifunctional Redox Modulators Protect Auditory, Visual, and Cognitive Function. Antioxid Redox Signal 2021; 36:1136-1157. [PMID: 34162214 PMCID: PMC9221172 DOI: 10.1089/ars.2021.0129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 12/26/2022]
Abstract
Significance: Oxidative stress contributes to vision, hearing and neurodegenerative disorders. Currently, no treatments prevent these disorders; therefore, there is an urgent need for redox modulators that can prevent these disorders. Recent Advances: Oxidative stress is associated with the generation of reactive oxygen species (ROS) and reactive nitrogen species, metal dyshomeostasis, and mitochondrial dysfunction. Here, we discuss the role that oxidative stress and metal dyshomeostasis play in hearing loss, visual impairments, and neurodegeneration and discuss the benefits of a new class of multifunctional redox modulators (MFRMs) that suppress sensory and neural degeneration. MFRMs not only reduce free radicals but also independently bind transition metals associated with the generation of hydroxyl radicals. The MFRMs redistribute zinc from neurotoxic amyloid beta zinc (Aβ:Zn) complexes to the cytoplasm, facilitating the degradation of Aβ plaques by matrix metalloprotease-2 (MMP-2). Although MFRMs bind copper (Cu1+, Cu2+), iron (Fe2+, Fe3+), zinc (Zn2+), and manganese (Mn2+), they do not deplete free cytoplasmic Zn+2 and they protect mitochondria from Mn+2-induced dysfunction. Oral administration of MFRMs reduce ROS-induced cataracts, protect the retina from light-induced degeneration, reduce neurotoxic Aβ:Zn plaque formation, and protect auditory hair cells from noise-induced hearing loss. Critical Issues: Regulation of redox balance is essential for clinical efficacy in maintaining sensory functions. Future Directions: Future use of these MFRMs requires additional pharmacokinetic, pharmacodynamics, and toxicological data to bring them into widespread clinical use. Additional animal studies are also needed to determine whether MFRMs can prevent neurodegeneration, dementia, and other forms of vision and hearing loss.
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Affiliation(s)
- Peter F. Kador
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Richard Salvi
- Center for Hearing and Deafness, University at Buffalo, Buffalo, New York, USA
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14
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Aranaz M, Costas-Rodríguez M, Lobo L, García M, González-Iglesias H, Pereiro R, Vanhaecke F. Homeostatic alterations related to total antioxidant capacity, elemental concentrations and isotopic compositions in aqueous humor of glaucoma patients. Anal Bioanal Chem 2021; 414:515-524. [PMID: 34173037 PMCID: PMC8748375 DOI: 10.1007/s00216-021-03467-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/04/2021] [Accepted: 06/09/2021] [Indexed: 01/05/2023]
Abstract
Glaucoma is a multifactorial eye disease, characterized by progressive optic neurodegeneration. Elevation of the intraocular pressure is the main risk factor for glaucoma and is a consequence of an imbalance in the aqueous humor hydrodynamics, the physiology of which is influenced by the homeostatic equilibrium of essential elements, oxidative stress, and antioxidants. The aim of this work was to study local alterations in glaucomatous patients from two different, but connected, points of view: (i) the total antioxidant capacity (as an indicator of oxidative damage) and (ii) the concentration of mineral elements and their isotopic composition. Such objective was pursued using aqueous humor from patients diagnosed with pseudoexfoliation glaucoma (PEXG, n = 17) and primary open-angle glaucoma (POAG, n = 5) and age-matched control subjects (n = 16). The total antioxidant capacity (TAC) was examined in both aqueous humor and 60 serum samples (n = 20 controls, n = 20 for PEXG, and n = 20 for POAG), both showing higher TAC for the glaucoma population. The concentrations of the essential mineral elements (Cu, Fe, Mg, Na, P, and Zn) and the isotopic compositions of Cu and Zn were determined in aqueous humor using single-collector and multi-collector inductively coupled plasma–mass spectrometry, respectively. Significant differences were established for Mg and P levels when comparing the results for glaucomatous patients with those for the control population (p < 0.01 and p < 0.05 for Mg and P respectively, ANOVA and Kruskal-Wallis). The Zn isotopic composition was significantly shifted from that for the control population for PEXG patients. A significant difference in the isotopic composition of Zn was also established between the PEXG and POAG glaucoma cohorts.
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Affiliation(s)
- Marta Aranaz
- Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julián Clavería 8, 33006, Oviedo, Spain
| | - Marta Costas-Rodríguez
- Department of Chemistry, Atomic & Mass Spectrometry - A&MS Research Unit, Ghent University, Campus Sterre, Krijgslaan 281 - S12, 9000, Ghent, Belgium.
| | - Lara Lobo
- Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julián Clavería 8, 33006, Oviedo, Spain.
| | - Montserrat García
- Instituto Oftalmológico Fernández-Vega, Avda. Fernández-Vega 34, 33012, Oviedo, Spain.,Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, Avda. Fernández-Vega 34, 33012, Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto Oftalmológico Fernández-Vega, Avda. Fernández-Vega 34, 33012, Oviedo, Spain.,Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, Avda. Fernández-Vega 34, 33012, Oviedo, Spain
| | - Rosario Pereiro
- Department of Physical and Analytical Chemistry, University of Oviedo, Avda. Julián Clavería 8, 33006, Oviedo, Spain.,Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, Avda. Fernández-Vega 34, 33012, Oviedo, Spain
| | - Frank Vanhaecke
- Department of Chemistry, Atomic & Mass Spectrometry - A&MS Research Unit, Ghent University, Campus Sterre, Krijgslaan 281 - S12, 9000, Ghent, Belgium
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15
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Álvarez-Barrios A, Álvarez L, García M, Artime E, Pereiro R, González-Iglesias H. Antioxidant Defenses in the Human Eye: A Focus on Metallothioneins. Antioxidants (Basel) 2021; 10:89. [PMID: 33440661 PMCID: PMC7826537 DOI: 10.3390/antiox10010089] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
The human eye, the highly specialized organ of vision, is greatly influenced by oxidants of endogenous and exogenous origin. Oxidative stress affects all structures of the human eye with special emphasis on the ocular surface, the lens, the retina and its retinal pigment epithelium, which are considered natural barriers of antioxidant protection, contributing to the onset and/or progression of eye diseases. These ocular structures contain a complex antioxidant defense system slightly different along the eye depending on cell tissue. In addition to widely studied enzymatic antioxidants, including superoxide dismutase, glutathione peroxidase, catalase, peroxiredoxins and selenoproteins, inter alia, metallothioneins (MTs) are considered antioxidant proteins of growing interest with further cell-mediated functions. This family of cysteine rich and low molecular mass proteins captures and neutralizes free radicals in a redox-dependent mechanism involving zinc binding and release. The state of the art of MTs, including the isoforms classification, the main functions described to date, the Zn-MT redox cycle as antioxidant defense system, and the antioxidant activity of Zn-MTs in the ocular surface, lens, retina and its retinal pigment epithelium, dependent on the number of occupied zinc-binding sites, will be comprehensively reviewed.
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Affiliation(s)
- Ana Álvarez-Barrios
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Lydia Álvarez
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Montserrat García
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
| | - Enol Artime
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Rosario Pereiro
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
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16
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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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17
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Ortiz-Melo MT, Garcia-Murillo MJ, Salazar-Rojas VM, Campos JE, Castro-Muñozledo F. Transcriptional profiles along cell programming into corneal epithelial differentiation. Exp Eye Res 2020; 202:108302. [PMID: 33098888 DOI: 10.1016/j.exer.2020.108302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/23/2020] [Accepted: 10/12/2020] [Indexed: 12/15/2022]
Abstract
Using the rabbit corneal epithelial cell line RCE1(5T5) as a model, we analyzed three differentiation stages, distinguished on basis to the growth state of cultured cells and after studying the expression of transcription factors such as Oct4, Pax6 and ΔNp63α, selected differentiation markers, and signaling or epigenetic markers such as Notch receptors and Prdm3. Namely, proliferative non-differentiated cells, committed cells, and cells that constitute a stratified epithelium with a limbal epithelial-like structure. RNAseq based transcriptome analysis showed that 4891 genes were differentially expressed among these stages displaying distinctive gene signatures: proliferative cells had 1278 genes as gene signature, and seem to be early epithelial progenitors with an Oct4+, KLF4+, Myc+, ΔNp63α+, ABCG2+, Vimentin+, Zeb1+, VANGL1+, Krt3-, Krt12- phenotype. Committed cells had a gene signature with 417 genes and displayed markers indicative of the beginning of corneal differentiation, and genes characteristic of proliferative cells; we found the possible participation of Six3 and Six4 transcription factors along this stage. The third stage matches with a stratified corneal epithelium (gene signature comprising 979 genes) and is typified by an increase in the expression of WNT10A and NOTCH 2 and 3 signaling and Cux1 transcription factor, besides Pax6, KLF4 or Sox9. The differentiated cells express about 50% of the genes that belong to the Epidermal Differentiation Complex (EDC). Analysis of the differences between corneal epithelium and epidermis could be crucial to understand the regulatory mechanisms that lead to the expression of the differentiated phenotype.
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Affiliation(s)
- María Teresa Ortiz-Melo
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740. México City, 07000, Mexico; Unidad de Biotecnología y Prototipos, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Ap. Postal 314, 54000, Tlalnepantla, Edo. de México, Mexico; Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México. Unidad de Posgrado, Edificio A, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, C.P. 04510, Ciudad de México, Mexico
| | - Maria Jimena Garcia-Murillo
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740. México City, 07000, Mexico
| | - Víctor Manuel Salazar-Rojas
- Unidad de Biotecnología y Prototipos, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Ap. Postal 314, 54000, Tlalnepantla, Edo. de México, Mexico
| | - Jorge E Campos
- Unidad de Biotecnología y Prototipos, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Ap. Postal 314, 54000, Tlalnepantla, Edo. de México, Mexico
| | - Federico Castro-Muñozledo
- Department of Cell Biology, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. Postal 14-740. México City, 07000, Mexico.
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18
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Emri E, Kortvely E, Dammeier S, Klose F, Simpson D, den Hollander AI, Ueffing M, Lengyel I. A Multi-Omics Approach Identifies Key Regulatory Pathways Induced by Long-Term Zinc Supplementation in Human Primary Retinal Pigment Epithelium. Nutrients 2020; 12:E3051. [PMID: 33036197 PMCID: PMC7601425 DOI: 10.3390/nu12103051] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/01/2020] [Accepted: 10/01/2020] [Indexed: 12/14/2022] Open
Abstract
In age-related macular degeneration (AMD), both systemic and local zinc levels decline. Elevation of zinc in clinical studies delayed the progression to end-stage AMD. However, the molecular pathways underpinning this beneficial effect are not yet identified. In this study, we used differentiated primary human fetal retinal pigment epithelium (RPE) cultures and long-term zinc supplementation to carry out a combined transcriptome, proteome and secretome analysis from three genetically different human donors. After combining significant differences, we identified the complex molecular networks using Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA). The cell cultures from the three donors showed extensive pigmentation, development of microvilli and basal infoldings and responded to zinc supplementation with an increase in transepithelial electrical resistance (TEER) (apical supplementation: 443.2 ± 79.3%, basal supplementation: 424.9 ± 116.8%, compared to control: 317.5 ± 98.2%). Significant changes were observed in the expression of 1044 genes, 151 cellular proteins and 124 secreted proteins. Gene set enrichment analysis revealed changes in specific molecular pathways related to cell adhesion/polarity, extracellular matrix organization, protein processing/transport, and oxidative stress response by zinc and identified a key upstream regulator effect similar to that of TGFB1.
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Affiliation(s)
- Eszter Emri
- Wellcome Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, Northern Ireland, UK; (E.E.); (D.S.)
- Roche Pharma Research and Early Development, Immunology, Infectious Diseases and Ophthalmology (I2O) Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland;
| | - Elod Kortvely
- Roche Pharma Research and Early Development, Immunology, Infectious Diseases and Ophthalmology (I2O) Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., 4070 Basel, Switzerland;
- Institute for Ophthalmic Research, University of Tubingen, D-72076 Tubingen, Germany; (S.D.); (F.K.); (M.U.)
| | - Sascha Dammeier
- Institute for Ophthalmic Research, University of Tubingen, D-72076 Tubingen, Germany; (S.D.); (F.K.); (M.U.)
| | - Franziska Klose
- Institute for Ophthalmic Research, University of Tubingen, D-72076 Tubingen, Germany; (S.D.); (F.K.); (M.U.)
| | - David Simpson
- Wellcome Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, Northern Ireland, UK; (E.E.); (D.S.)
| | | | - Anneke I. den Hollander
- Departments of Ophthalmology and Genetics, Radboud University Medical Center, 6525EX Nijmegen, The Netherlands;
| | - Marius Ueffing
- Institute for Ophthalmic Research, University of Tubingen, D-72076 Tubingen, Germany; (S.D.); (F.K.); (M.U.)
| | - Imre Lengyel
- Wellcome Wolfson Institute for Experimental Medicine, Queen’s University of Belfast, Belfast BT97BL, Northern Ireland, UK; (E.E.); (D.S.)
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19
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Koh JY, Lee SJ. Metallothionein-3 as a multifunctional player in the control of cellular processes and diseases. Mol Brain 2020; 13:116. [PMID: 32843100 PMCID: PMC7448430 DOI: 10.1186/s13041-020-00654-w] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/12/2020] [Indexed: 01/06/2023] Open
Abstract
Transition metals, such as iron, copper, and zinc, play a very important role in life as the regulators of various physiochemical reactions in cells. Abnormal distribution and concentration of these metals in the body are closely associated with various diseases including ischemic seizure, Alzheimer's disease, diabetes, and cancer. Iron and copper are known to be mainly involved in in vivo redox reaction. Zinc controls a variety of intracellular metabolism via binding to lots of proteins in cells and altering their structure and function. Metallothionein-3 (MT3) is a representative zinc binding protein predominant in the brain. Although the role of MT3 in other organs still needs to be elucidated, many reports have suggested critical roles for the protein in the control of a variety of cellular homeostasis. Here, we review various biological functions of MT3, focusing on different cellular molecules and diseases involving MT3 in the body.
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Affiliation(s)
- Jae-Young Koh
- Neural Injury Research Center, Asan Institute for Life Sciences, University of Ulsan, College of Medicine, Seoul, 05505, Republic of Korea
- Department of Neurology, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, 05505, Republic of Korea
| | - Sook-Jeong Lee
- Department of Bioactive Material Science, Jeonbuk National University, Jeonju, Jeollabuk-do, 54896, Republic of Korea.
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20
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Wang F, Zheng F, Liu F. Effects of triclosan on antioxidant- and apoptosis-related genes expression in the gill and ovary of zebrafish. Exp Anim 2020; 69:199-206. [PMID: 31839624 PMCID: PMC7220719 DOI: 10.1538/expanim.19-0115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/11/2019] [Indexed: 12/13/2022] Open
Abstract
Triclosan (TCS) is a broad-spectrum antibacterial and anti-fungal agent used in a broad variety of personal care products (PCPs) throughout the world. However, the molecular mechanism of TCS's effects on the gill and ovary of fish is not clear. In this study, the effects of TCS exposure on expression of antioxidant- and apoptosis-related genes were investigated in the gill and ovary of zebrafish (Danio rerio). Zebrafish were exposed to 0, 17, 34, or 68 µg/l TCS for 42 days. Antioxidant-related genes (SOD, GPx1a, CAT, sMT-B, and MT-2) in the gill were significantly downregulated in the 34 (except GPx1a) and 68 µg/l TCS groups, and these genes (except MT-2) in the ovary were significantly downregulated in the 68 µg/l TCS group. Apoptosis-related gene (Bax and p53) expression level in the gill were significantly downregulated in the 68 µg/l TCS group, while the ratios of BCL-2 to Bax and MDM2 gene were significantly upregulated. The Bax gene in the ovary was significantly upregulated in the 34 and 68 µg/l TCS groups, while the ratio of BCL-2 to Bax was significantly downregulated. Moreover, the p53 gene in the ovary in the 34 µg/l TCS group was significantly upregulated. In addition, the MDA contents in the gill in the 34 and 68 μg/l TCS treated groups and in the ovary in 68 μg/l group were significantly increased. The results showed that the higher dose of TCS might cause oxidative damage in the gills and ovaries and accelerate ROS-dependent ovary apoptosis in zebrafish.
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Affiliation(s)
- Fan Wang
- School of Life Sciences, Luoyang Normal University, No. 6 Jinqing Road, Yinbin District, Luoyang 471934, P.R. China
| | - Fangfang Zheng
- School of Life Sciences, Luoyang Normal University, No. 6 Jinqing Road, Yinbin District, Luoyang 471934, P.R. China
| | - Fei Liu
- School of Life Sciences, Luoyang Normal University, No. 6 Jinqing Road, Yinbin District, Luoyang 471934, P.R. China
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21
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Making a case for metallothioneins conferring cardioprotection in pulmonary hypertension. Med Hypotheses 2020; 137:109572. [DOI: 10.1016/j.mehy.2020.109572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/30/2019] [Accepted: 01/15/2020] [Indexed: 11/23/2022]
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22
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Heesterbeek TJ, Lorés-Motta L, Hoyng CB, Lechanteur YTE, den Hollander AI. Risk factors for progression of age-related macular degeneration. Ophthalmic Physiol Opt 2020; 40:140-170. [PMID: 32100327 PMCID: PMC7155063 DOI: 10.1111/opo.12675] [Citation(s) in RCA: 176] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/18/2020] [Indexed: 12/18/2022]
Abstract
Purpose Age‐related macular degeneration (AMD) is a degenerative disease of the macula, often leading to progressive vision loss. The rate of disease progression can vary among individuals and has been associated with multiple risk factors. In this review, we provide an overview of the current literature investigating phenotypic, demographic, environmental, genetic, and molecular risk factors, and propose the most consistently identified risk factors for disease progression in AMD based on these studies. Finally, we describe the potential use of these risk factors for personalised healthcare. Recent findings While phenotypic risk factors such as drusen and pigment abnormalities become more important to predict disease progression during the course of the disease, demographic, environmental, genetic and molecular risk factors are more valuable at earlier disease stages. Demographic and environmental risk factors such as age and smoking are consistently reported to be related to disease progression, while other factors such as sex, body mass index (BMI) and education are less often associated. Of all known AMD variants, variants that are most consistently reported with disease progression are rs10922109 and rs570618 in CFH, rs116503776 in C2/CFB/SKIV2L, rs3750846 in ARMS2/HTRA1 and rs2230199 in C3. However, it seems likely that other AMD variants also contribute to disease progression but to a lesser extent. Rare variants have probably a large effect on disease progression in highly affected families. Furthermore, current prediction models do not include molecular risk factors, while these factors can be measured accurately in the blood. Possible promising molecular risk factors are High‐Density Lipoprotein Cholesterol (HDL‐C), Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), zeaxanthin and lutein. Summary Phenotypic, demographic, environmental, genetic and molecular risk factors can be combined in prediction models to predict disease progression, but the selection of the proper risk factors for personalised risk prediction will differ among individuals and is dependent on their current disease stage. Future prediction models should include a wider set of genetic variants to determine the genetic risk more accurately, and rare variants should be taken into account in highly affected families. In addition, adding molecular factors in prediction models may lead to preventive strategies and personalised advice.
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Affiliation(s)
- Thomas J Heesterbeek
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Laura Lorés-Motta
- Departments of, 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
| | - Carel B Hoyng
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Yara T E Lechanteur
- Departments of, Department of, Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Departments of, 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
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23
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Melenbacher A, Korkola NC, Stillman MJ. The pathways and domain specificity of Cu(i) binding to human metallothionein 1A. Metallomics 2020; 12:1951-1964. [DOI: 10.1039/d0mt00215a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We describe the sequential formation of 3 key Cu(i)–thiolate clusters in human metallothionein 1A using a combination of ESI-MS and phosphorescence lifetime methods.
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Affiliation(s)
- Adyn Melenbacher
- Department of Chemistry
- The University of Western Ontario
- London
- Canada
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24
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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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25
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The Zinc-Metallothionein Redox System Reduces Oxidative Stress in Retinal Pigment Epithelial Cells. Nutrients 2018; 10:nu10121874. [PMID: 30513827 PMCID: PMC6315569 DOI: 10.3390/nu10121874] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 11/22/2018] [Accepted: 11/27/2018] [Indexed: 12/22/2022] Open
Abstract
Oxidative stress affects all the structures of the human eye, particularly the retina and its retinal pigment epithelium (RPE). The RPE limits oxidative damage by several protective mechanisms, including the non-enzymatic antioxidant system zinc-metallothionein (Zn-MT). This work aimed to investigate the role of Zn-MT in the protection of RPE from the oxidative damage of reactive oxygen intermediates by analytical and biochemical-based techniques. The Zn-MT system was induced in an in vitro model of RPE cells and determined by elemental mass spectrometry with enriched isotopes and mathematical calculations. Induced-oxidative stress was quantified using fluorescent probes. We observed that 25, 50 or 100 μM of zinc induced Zn-MT synthesis (1.6-, 3.6- and 11.9-fold, respectively), while pre-treated cells with zinc (25, 50, and 100 μM) and subsequent 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH) treatment increased Zn-MT levels in a lesser extent (0.8-, 2.1-, 6.1-fold, respectively), exerting a stoichiometric transition in the Zn-MT complex. Moreover, AAPH treatment decreased MT levels (0.4-fold), while the stoichiometry remained constant or slightly higher when compared to non-treated cells. Convincingly, induction of Zn-MT significantly attenuated oxidative stress produced by free radicals’ generators. We conclude that the stoichiometry of Zn-MT plays an important role in oxidative stress response, related with cellular metal homeostasis.
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26
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Pulmonary arterial hypertension and the potential roles of metallothioneins: A focused review. Life Sci 2018; 214:77-83. [PMID: 30355531 DOI: 10.1016/j.lfs.2018.10.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/10/2018] [Accepted: 10/19/2018] [Indexed: 12/17/2022]
Abstract
The pathophysiology of pulmonary arterial hypertension (PAH) is underlined by cell proliferation and vasoconstriction of pulmonary arterioles this involves multiple molecular factors or proteins, but it is not clear what the exact roles of these factors/proteins are. In addition, there may be other factors/proteins that have not been identified that contribute to PAH pathophysiology. Therefore, research has focused on investigating novel role players, in order to facilitate a better understanding of how PAH develop. Evidence suggest that mitochondrial regulators are key role players in PAH pathophysiology, but regulators that have not received sufficient attention in PAH are metallothioneins (MTs). In PAH patients, MT expression is elevated compared to healthy individuals, suggesting that MTs may be possible biomarkers. In other disease-models, MTs have been shown to regulate cell proliferation and vasoconstriction, processes that are instrumental in PAH pathophysiology. Due to the involvement of these processes in PAH pathophysiology and the ability of MTs to modulate them, this paper propose that cellular MTs may also play a role in PAH development. This paper suggests that PAH-research should perhaps begin to investigate the involvement of cellular MTs in the development of PAH.
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27
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Cruz-Alonso M, Fernandez B, García M, González-Iglesias H, Pereiro R. Quantitative Imaging of Specific Proteins in the Human Retina by Laser Ablation ICPMS using Bioconjugated Metal Nanoclusters as Labels. Anal Chem 2018; 90:12145-12151. [DOI: 10.1021/acs.analchem.8b03124] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- María Cruz-Alonso
- Department of Physical and Analytical Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo, Spain
| | - Beatriz Fernandez
- Department of Physical and Analytical Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo, Spain
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain
| | - Montserrat García
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega 34, 33012 Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega 34, 33012 Oviedo, Spain
| | - Rosario Pereiro
- Department of Physical and Analytical Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo, Spain
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain
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28
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Isolated domains of recombinant human apo-metallothionein 1A are folded at neutral pH: a denaturant and heat-induced unfolding study using ESI-MS. Biosci Rep 2018; 38:BSR20180592. [PMID: 29858425 PMCID: PMC6050192 DOI: 10.1042/bsr20180592] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 12/25/2022] Open
Abstract
Metallothioneins (MTs) are characterized by their high metal loading capacity, small molecular weight, and abundant cysteine residues. It has long been thought that metal-free, or apo-MT peptides were unstructured and only adopted as a distinct conformation upon forming the metal clusters, described as metal-induced folding. More recent studies have suggested that the presence of a globular, yet loosely defined structure actually exists that can be disrupted or unfolded. Residue modification and ion-mobility ESI (IM-ESI)-MS have been used to examine this unusual unfolding process. The structure of apo-MT plays a critical role as the starting point in the flexible metalation pathways that can accommodate numerous soft metals. ESI-MS measurements of the product species formed following the cysteine alkylation of the isolated domain fragments of recombinant human apo-MT 1A with n-ethylmaleimide (NEM) were used in the present study to monitor the denaturant- and heat-induced unfolding at physiological pH. The results indicate that these apo-MT fragments adopt distinct structures at neutral pH that react co-operatively with NEM when folded and non-cooperatively when heated or exposed to high concentrations of the denaturant guanidinium chloride (GdmCl). From these studies, we can conclude that at neutral pH, the domain fragments are folded into globular structures where some of the free cysteine residues are buried within the core and are stabilized by hydrogen bonds. Metalation therefore, must take place from the folded conformation.
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29
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Chromatographic separation of similar post-translationally modified metallothioneins reveals the changing conformations of apo-MT upon cysteine alkylation by high resolution LC-ESI-MS. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018. [PMID: 29518586 DOI: 10.1016/j.bbapap.2018.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Metallothioneins (MTs) are a class of small cysteine-rich proteins essential for Zn and Cu homeostasis, heavy metal detoxification, and cellular redox chemistry. Herein, we describe the separation and characterization of MTs differentially modified with N-ethylmaleimide (NEM) by liquid chromatography-mass spectrometry (LC-MS). The full-length recombinant MT isoform 1a as well as is isolated domain fragments were first alkylated, then separated on column with subsequent detection by ultra-high resolution ESI-MS. Different behavior was observed for the three peptides with the full-length protein and the isolated α-domain exhibiting similar separation characteristics. For the isolated β-domain, the smallest peptide with 9 cysteines in the sequence, each alkylated species was well separated, indicating large changes in protein conformation. For the full-length (20 cysteines in the sequence) and α-domain (11 cysteiens in the sequence) peptides, the apo- and lightly alkylated species co-eluted, indicating similar structural properties. However, the more extensively alkylated species were well separated from each other, indicating the sequential unfolding of the apo-MT peptides and providing evidence for the mechanistic explanation for the cooperative alkylation reaction observed for NEM and other bulky and hydrophobic alkylation reagents. We show for the first time clear separation of highly similar MTs, differing by only +125 Da, and can infer structural properties from the LC-MS data, analogous to more complicated and less ubiquitous ion-mobility experiments. The data suggest a compact globular structure for each of the apo-MTs, but where the β-domain is more easily unfolded. This differential folding stability may have biological implications in terms of domain-specific participation of MT in cellular redox chemistry and resulting metal release.
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30
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Rodríguez-Menéndez S, Fernández B, García M, Álvarez L, Luisa Fernández M, Sanz-Medel A, Coca-Prados M, Pereiro R, González-Iglesias H. Quantitative study of zinc and metallothioneins in the human retina and RPE cells by mass spectrometry-based methodologies. Talanta 2018; 178:222-230. [DOI: 10.1016/j.talanta.2017.09.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/06/2017] [Accepted: 09/10/2017] [Indexed: 12/17/2022]
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31
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Bioimaging of metallothioneins in ocular tissue sections by laser ablation-ICP-MS using bioconjugated gold nanoclusters as specific tags. Mikrochim Acta 2017; 185:64. [DOI: 10.1007/s00604-017-2597-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/30/2017] [Indexed: 12/12/2022]
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32
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Irvine GW, Stillman MJ. Residue Modification and Mass Spectrometry for the Investigation of Structural and Metalation Properties of Metallothionein and Cysteine-Rich Proteins. Int J Mol Sci 2017; 18:ijms18050913. [PMID: 28445428 PMCID: PMC5454826 DOI: 10.3390/ijms18050913] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/18/2017] [Accepted: 04/20/2017] [Indexed: 12/23/2022] Open
Abstract
Structural information regarding metallothioneins (MTs) has been hard to come by due to its highly dynamic nature in the absence of metal-thiolate cluster formation and crystallization difficulties. Thus, typical spectroscopic methods for structural determination are limited in their usefulness when applied to MTs. Mass spectrometric methods have revolutionized our understanding of protein dynamics, structure, and folding. Recently, advances have been made in residue modification mass spectrometry in order to probe the hard-to-characterize structure of apo- and partially metalated MTs. By using different cysteine specific alkylation reagents, time dependent electrospray ionization mass spectrometry (ESI-MS), and step-wise “snapshot” ESI-MS, we are beginning to understand the dynamics of the conformers of apo-MT and related species. In this review we highlight recent papers that use these and similar techniques for structure elucidation and attempt to explain in a concise manner the data interpretations of these complex methods. We expect increasing resolution in our picture of the structural conformations of metal-free MTs as these techniques are more widely adopted and combined with other promising tools for structural elucidation.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, ON N6A 3K7, Canada.
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, ON N6A 3K7, Canada.
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33
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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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Irvine GW, Santolini M, Stillman MJ. Selective cysteine modification of metal-free human metallothionein 1a and its isolated domain fragments: Solution structural properties revealed via ESI-MS. Protein Sci 2017; 26:960-971. [PMID: 28187517 DOI: 10.1002/pro.3139] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/06/2017] [Accepted: 02/07/2017] [Indexed: 01/11/2023]
Abstract
Human metallothionein 1a, a protein with two cysteine-rich metal-binding domains (α with 11 Cys and β with 9), was analyzed in its metal-free form by selective, covalent Cys modification coupled with ESI-MS. The modification profiles of the isolated β- and α-fragments reacted with p-benzoquinone (Bq), N-ethylmalemide (NEM) and iodoacetamide (IAM) were compared with the full length protein using ESI-mass spectral data to follow the reaction pathway. Under denaturing conditions at low pH, the reaction profile with each modifier followed pathways that resulted in stochastic, Normal distributions of species whose maxima was equal to the mol. eq. of modifier added. Our interpretation of modification at this pH is that reaction with the cysteines is unimpeded when the full protein or those of its isolated domains are denatured. At neutral pH, where the protein is expected to be folded in a more compact structure, there is a difference in the larger Bq and NEM modification, whose reaction profiles indicate a cooperative pattern. The reaction profile with IAM under native conditions follows a similar stochastic distribution as at low pH, suggesting that this modifier is small enough to access the cysteines unimpeded by the compact structure. The data emphasize the utility of residue modification coupled with electrospray ionization mass spectrometry for the study of protein structure.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
| | - Melissa Santolini
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
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Scheller JS, Irvine GW, Wong DL, Hartwig A, Stillman MJ. Stepwise copper(i) binding to metallothionein: a mixed cooperative and non-cooperative mechanism for all 20 copper ions. Metallomics 2017; 9:447-462. [DOI: 10.1039/c7mt00041c] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Irvine GW, Pinter TBJ, Stillman MJ. Defining the metal binding pathways of human metallothionein 1a: balancing zinc availability and cadmium seclusion. Metallomics 2016; 8:71-81. [PMID: 26583802 DOI: 10.1039/c5mt00225g] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Metallothioneins (MTs) are cysteine-rich, metal-binding proteins that are found throughout Nature. This ubiquity highlights their importance in essential metal regulation, heavy metal detoxification and cellular redox chemistry. Missing from the current description of MT function is the underlying mechanism by which MTs achieve their proposed biological functions. To date, there have been conflicting reports on the mechanism of metal binding and the structures of the metal binding intermediates formed during metalation of apoMTs. The form of the metal-bound intermediates dictates the metal sequestering and metal-donating properties of the protein. Through a detailed analysis of spectral data from electrospray ionization mass spectromeric and circular dichroism methods we report that Zn(ii) and Cd(ii) metalation of the human MT1a takes place through two distinct pathways. The first pathway involves formation of beaded structures with up to five metals bound terminally to the 20 cysteines of the protein via a noncooperative mechanism. The second pathway is dominated by the formation of the four-metal domain cluster structure M4SCYS11via a cooperative mechanism. We report that there are different pathway preferences for Zn(ii) and Cd(ii) metalation of apo-hMT1a. Cd(ii) binding follows the beaded pathway above pH 7.1 but beginning below pH 7.1 the clustered (Cd4Scys11) pathway begins to dominate. In contrast, Zn(ii) binding follows the terminal, "beaded", pathway at all physiologically relevant pH (pH ≥ 5.2) only following the clustered pathway below pH 5.1. The results presented here allow us to reconcile the conflicting reports concerning the presence of different metalation intermediates of MTs. The conflict regarding cooperative versus noncooperative binding mechanisms is also reconciled with the experimental results described here. These two metal-specific pathways and the presence of radically different intermediate structures provide insight into the multi-functional nature of MT: binding Zn(ii) terminally for donation to metalloenzymes and sequestering toxic Cd(ii) in a cluster structure.
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Affiliation(s)
- Gordon W Irvine
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
| | - Tyler B J Pinter
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
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Wezynfeld NE, Stefaniak E, Stachucy K, Drozd A, Płonka D, Drew SC, Krężel A, Bal W. Resistance of Cu(Aβ4-16) to Copper Capture by Metallothionein-3 Supports a Function for the Aβ4-42 Peptide as a Synaptic Cu(II) Scavenger. Angew Chem Int Ed Engl 2016; 55:8235-8. [PMID: 27238224 DOI: 10.1002/anie.201511968] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/23/2015] [Indexed: 01/16/2023]
Abstract
Aβ4-42 is a major species of Aβ peptide in the brains of both healthy individuals and those affected by Alzheimer's disease. It has recently been demonstrated to bind Cu(II) with an affinity approximately 3000 times higher than the commonly studied Aβ1-42 and Aβ1-40 peptides, which are implicated in the pathogenesis of Alzheimer's disease. Metallothionein-3, a protein considered to orchestrate copper and zinc metabolism in the brain and provide antioxidant protection, was shown to extract Cu(II) from Aβ1-40 when acting in its native Zn7 MT-3 form. This reaction is assumed to underlie the neuroprotective effect of Zn7 MT-3 against Aβ toxicity. In this work, we used the truncated model peptides Aβ1-16 and Aβ4-16 to demonstrate that the high-affinity Cu(II) complex of Aβ4-16 is resistant to Zn7 MT-3 reactivity. This indicates that the analogous complex of the full-length peptide Cu(Aβ4-42) will not yield copper to MT-3 in the brain, thus supporting the concept of a physiological role for Aβ4-42 as a Cu(II) scavenger in the synaptic cleft.
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Affiliation(s)
- Nina E Wezynfeld
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Ewelina Stefaniak
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Kinga Stachucy
- Laboratory of Chemical Biology, University of Wrocław, Poland
| | - Agnieszka Drozd
- Laboratory of Chemical Biology, University of Wrocław, Poland
| | - Dawid Płonka
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Simon C Drew
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Australia
| | - Artur Krężel
- Laboratory of Chemical Biology, University of Wrocław, Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland.
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Wezynfeld NE, Stefaniak E, Stachucy K, Drozd A, Płonka D, Drew SC, Krężel A, Bal W. Resistance of Cu(Aβ4
–
16) to Copper Capture by Metallothionein‐3 Supports a Function for the Aβ4
–
42 Peptide as a Synaptic Cu
II
Scavenger. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201511968] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nina E. Wezynfeld
- Institute of Biochemistry and Biophysics Polish Academy of Sciences Pawińskiego 5a 02-106 Warsaw Poland
| | - Ewelina Stefaniak
- Institute of Biochemistry and Biophysics Polish Academy of Sciences Pawińskiego 5a 02-106 Warsaw Poland
| | - Kinga Stachucy
- Laboratory of Chemical Biology University of Wrocław Poland
| | | | - Dawid Płonka
- Institute of Biochemistry and Biophysics Polish Academy of Sciences Pawińskiego 5a 02-106 Warsaw Poland
| | - Simon C. Drew
- Florey Department of Neuroscience and Mental Health The University of Melbourne Australia
| | - Artur Krężel
- Laboratory of Chemical Biology University of Wrocław Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics Polish Academy of Sciences Pawińskiego 5a 02-106 Warsaw Poland
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