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Aschner M, Skalny AV, Paoliello MMB, Tinkova MN, Martins AC, Santamaria A, Lee E, Rocha JBT, Farsky SHP, Tinkov AA. Retinal toxicity of heavy metals and its involvement in retinal pathology. Food Chem Toxicol 2024; 188:114685. [PMID: 38663763 DOI: 10.1016/j.fct.2024.114685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/16/2024] [Accepted: 04/22/2024] [Indexed: 05/04/2024]
Abstract
The objective of the present review is to discuss epidemiological evidence demonstrating the association between toxic metal (Cd, Pb, Hg, As, Sn, Ti, Tl) exposure and retinal pathology, along with the potential underlying molecular mechanisms. Epidemiological studies demonstrate that Cd, and to a lesser extent Pb exposure, are associated with age-related macular degeneration (AMD), while the existing evidence on the levels of these metals in patients with diabetic retinopathy is scarce. Epidemiological data on the association between other toxic metals and metalloids including mercury (Hg) and arsenic (As), are limited. Clinical reports and laboratory in vivo studies have shown structural alterations in different layers of retina following metal exposure. Examination of retina samples demonstrate that toxic metals can accumulate in the retina, and the rate of accumulation appears to increase with age. Experimental studies in vivo and in vitro studies in APRE-19 and D407 cells demonstrate that toxic metal exposure may cause retinal damage through oxidative stress, apoptosis, DNA damage, mitochondrial dysfunction, endoplasmic reticulum stress, impaired retinogenesis, and retinal inflammation. However, further epidemiological as well as laboratory studies are required for understanding the underlying molecular mechanisms and identifying of the potential therapeutic targets and estimation of the dose-response effects.
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Affiliation(s)
- Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Anatoly V Skalny
- Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, Yaroslavl, 150003, Russia; Center of Bioelementology and Human Ecology, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow, 119435, Russia
| | - Monica M B Paoliello
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY 10461, USA
| | | | - Airton C Martins
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Abel Santamaria
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico; Laboratorio de Nanotecnología y Nanomedicina, Departamento de Cuidado de La Salud, Universidad Autónoma Metropolitana-Xochimilco, Mexico City 04960, Mexico
| | - Eunsook Lee
- Department of Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
| | - Joao B T Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil
| | - Sandra H P Farsky
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of Sao Paulo, São Paulo 05508-000, SP, Brazil
| | - Alexey A Tinkov
- Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, Yaroslavl, 150003, Russia; Center of Bioelementology and Human Ecology, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow, 119435, Russia.
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2
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Bjørklund G, Đorđević AB, Hamdan H, Wallace DR, Peana M. Metal-induced autoimmunity in neurological disorders: A review of current understanding and future directions. Autoimmun Rev 2024; 23:103509. [PMID: 38159894 DOI: 10.1016/j.autrev.2023.103509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Autoimmunity is a multifaceted disorder influenced by both genetic and environmental factors, and metal exposure has been implicated as a potential catalyst, especially in autoimmune diseases affecting the central nervous system. Notably, metals like mercury, lead, and aluminum exhibit well-established neurotoxic effects, yet the precise mechanisms by which they elicit autoimmune responses in susceptible individuals remain unclear. Recent studies propose that metal-induced autoimmunity may arise from direct toxic effects on immune cells and tissues, coupled with indirect impacts on the gut microbiome and the blood-brain barrier. These effects can activate self-reactive T cells, prompting the production of autoantibodies, inflammatory responses, and tissue damage. Diagnosing metal-induced autoimmunity proves challenging due to nonspecific symptoms and a lack of reliable biomarkers. Treatment typically involves chelation therapy to eliminate excess metals and immunomodulatory agents to suppress autoimmune responses. Prevention strategies include lifestyle adjustments to reduce metal exposure and avoiding occupational and environmental risks. Prognosis is generally favorable with proper treatment; however, untreated cases may lead to autoimmune disorder progression and irreversible organ damage, particularly in the brain. Future research aims to identify genetic and environmental risk factors, enhance diagnostic precision, and explore novel treatment approaches for improved prevention and management of this intricate and debilitating disease.
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Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Mo i Rana, Norway.
| | | | - Halla Hamdan
- Department of Pharmacology, Oklahoma State University Center for Health Sciences, Tulsa, OK, United States
| | - David R Wallace
- Department of Pharmacology, Oklahoma State University Center for Health Sciences, Tulsa, OK, United States
| | - Massimiliano Peana
- Department of Chemical, Physical, Mathematical and Natural Sciences, University of Sassari, Italy.
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3
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Kim HS, Sarrafpour S, Teng CC, Liu J. External Disruption of Ocular Development in Utero. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2024; 97:41-48. [PMID: 38559457 PMCID: PMC10964818 DOI: 10.59249/rrmm8911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The intricate steps of human ocular embryology are impacted by cellular and genetic signaling pathways and a myriad of external elements that can affect pregnancy, such as environmental, metabolic, hormonal factors, medications, and intrauterine infections. This review focuses on presenting some of these factors to recognize the multifactorial nature of ocular development and highlight their clinical significance. This review is based on English-language articles sourced from PubMed, Web of Science, and Google Scholar; keywords searched included "ocular development in pregnancy," "ocular embryology," "maternal nutrition," "ophthalmic change," and "visual system development." While some animal models show the disruption of ocular embryology from these external factors, there are limited post-birth assessments in human studies. Much remains unknown about the precise mechanisms of how these external factors can disrupt normal ocular development in utero, and more significant research is needed to understand the pathophysiology of these disruptive effects further. Findings in this review emphasize the importance of additional research in understanding the dynamic association between factors impacting gestation and neonatal ocular development, particularly in the setting of limited resources.
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Affiliation(s)
- Hyun Sue Kim
- Virginia Tech Carilion School of Medicine, Roanoke, VA, USA
- Department of
Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT,
USA
| | - Soshian Sarrafpour
- Department of
Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT,
USA
| | - Christopher C. Teng
- Department of
Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT,
USA
| | - Ji Liu
- Department of
Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT,
USA
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Navarro-Sempere A, Martínez-Peinado P, Rodrigues AS, Garcia PV, Camarinho R, Grindlay G, Gras L, García M, Segovia Y. Metallothionein expression in the central nervous system in response to chronic heavy metal exposure: possible neuroprotective mechanism. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:8257-8269. [PMID: 37580456 PMCID: PMC10611846 DOI: 10.1007/s10653-023-01722-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/02/2023] [Indexed: 08/16/2023]
Abstract
It has been reported that volcanoes release several tonnes of mercury per year among other heavy metals through eruptions, fumaroles, or diffuse soil degassing. Since a high percentage of the world's population lives in the vicinity of an active volcano, the aim of this study is to evaluate the accumulation of these metals in the central nervous system and the presence of cellular mechanisms of heavy metal detoxification such as metallothioneins. To carry out this study, wild mice (Mus musculus) chronically exposed to an active volcanic environment were captured in Furnas village (Azores, Portugal) and compared with those trapped in a reference area (Rabo de Peixe, Azores, Portugal). On the one hand, the heavy metal load has been evaluated by analyzing brain and cerebellum using ICP-MS and a mercury analyzer and on the other hand, the presence of metallothionein 2A has been studied by immunofluorescence assays. Our results show a higher load of metals such as mercury, cadmium and lead in the central nervous system of exposed mice compared to non-exposed individuals and, in addition, a higher immunoreactivity for metallothionein 2A in different areas of the cerebrum and cerebellum indicating a possible neuroprotection process.
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Affiliation(s)
- A Navarro-Sempere
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain
| | - P Martínez-Peinado
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain
| | - A S Rodrigues
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- IVAR, Research Institute for Volcanology and Risk Assessment, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - P V Garcia
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- Centre for Ecology, Evolution and Environmental Changes and Azorean Biodiversity Group, CE3c, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - R Camarinho
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- IVAR, Research Institute for Volcanology and Risk Assessment, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - G Grindlay
- Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, PO Box 99, 03080, Alicante, Spain
| | - L Gras
- Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, PO Box 99, 03080, Alicante, Spain
| | - M García
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain
| | - Y Segovia
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain.
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Sather RN, Lee MS. Toxic Optic Neuropathy Due to Mercury in Skin Lightening Products. Neuroophthalmology 2023; 47:281-284. [PMID: 38145039 PMCID: PMC10745285 DOI: 10.1080/01658107.2023.2251580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/14/2023] [Indexed: 12/26/2023] Open
Abstract
Mercury has been described as been in daily household items such as soaps, skin-lightening creams (SLC), and topical disinfectants. Mercury exposure can reportedly cause damage to the optic nerve and retina. A 30-year-old Somali woman presented with decreased vision and was found to have bilateral optic atrophy. Neuroimaging and laboratory work-up for nutritional deficiencies, heavy metals, and syphilis were performed. Evaluation revealed normal neuroimaging and laboratory work-up except for elevated serum and urine mercury levels. Mercury levels at the initial blood test was 11.1 ug/L (normal limits < 10.0 ug/L) and was 15.7 ug/L on repeat testing. A 24-h urine test showed elevated mercury at 16 ug/24 h (normal limits < 2 ug/24 h). Evaluation of an unlabelled SLC that she was using showed the presence of mercury. It is worth testing for heavy metals in the work-up of bilateral optic atrophy. Clinicians should consider cosmetic products as a potential source of mercury exposure and recommend discontinuation if mercury is present.
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Affiliation(s)
- Richard N. Sather
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Michael S. Lee
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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Pamphlett R, Bishop DP. The toxic metal hypothesis for neurological disorders. Front Neurol 2023; 14:1173779. [PMID: 37426441 PMCID: PMC10328356 DOI: 10.3389/fneur.2023.1173779] [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: 02/25/2023] [Accepted: 05/30/2023] [Indexed: 07/11/2023] Open
Abstract
Multiple sclerosis and the major sporadic neurogenerative disorders, amyotrophic lateral sclerosis, Parkinson disease, and Alzheimer disease are considered to have both genetic and environmental components. Advances have been made in finding genetic predispositions to these disorders, but it has been difficult to pin down environmental agents that trigger them. Environmental toxic metals have been implicated in neurological disorders, since human exposure to toxic metals is common from anthropogenic and natural sources, and toxic metals have damaging properties that are suspected to underlie many of these disorders. Questions remain, however, as to how toxic metals enter the nervous system, if one or combinations of metals are sufficient to precipitate disease, and how toxic metal exposure results in different patterns of neuronal and white matter loss. The hypothesis presented here is that damage to selective locus ceruleus neurons from toxic metals causes dysfunction of the blood-brain barrier. This allows circulating toxicants to enter astrocytes, from where they are transferred to, and damage, oligodendrocytes, and neurons. The type of neurological disorder that arises depends on (i) which locus ceruleus neurons are damaged, (ii) genetic variants that give rise to susceptibility to toxic metal uptake, cytotoxicity, or clearance, (iii) the age, frequency, and duration of toxicant exposure, and (iv) the uptake of various mixtures of toxic metals. Evidence supporting this hypothesis is presented, concentrating on studies that have examined the distribution of toxic metals in the human nervous system. Clinicopathological features shared between neurological disorders are listed that can be linked to toxic metals. Details are provided on how the hypothesis applies to multiple sclerosis and the major neurodegenerative disorders. Further avenues to explore the toxic metal hypothesis for neurological disorders are suggested. In conclusion, environmental toxic metals may play a part in several common neurological disorders. While further evidence to support this hypothesis is needed, to protect the nervous system it would be prudent to take steps to reduce environmental toxic metal pollution from industrial, mining, and manufacturing sources, and from the burning of fossil fuels.
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Affiliation(s)
- Roger Pamphlett
- Department of Pathology, Brain and Mind Centre, School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
- Department of Neuropathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
- Hyphenated Mass Spectrometry Laboratory, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - David P. Bishop
- Hyphenated Mass Spectrometry Laboratory, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, NSW, Australia
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Abu Bakar N, Wan Ibrahim WN, Zulkiflli AR, Saleh Hodin NA, Kim TY, Ling YS, Md Ajat MM, Shaari K, Shohaimi S, Nasruddin NS, Mohd Faudzi SM, Kim CH. Embryonic mercury exposure in zebrafish: Alteration of metabolites and gene expression, related to visual and behavioral impairments. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 256:114862. [PMID: 37004432 DOI: 10.1016/j.ecoenv.2023.114862] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 03/05/2023] [Accepted: 03/30/2023] [Indexed: 06/19/2023]
Abstract
The widespread presence of mercury, a heavy metal found in the environment and used in numerous industries and domestic, raises concerns about its potential impact on human health. Nevertheless, the adverse effects of this environmental toxicant at low concentrations are often underestimated. There are emerging studies showing that accumulation of mercury in the eye may contribute to visual impairment and a comorbidity between autism spectrum disorders (ASD) trait and visual impairment. However, the underlying mechanism of visual impairment in humans and rodents is challenging. In response to this issue, zebrafish larvae with a cone-dominated retinal visual system were exposed to 100 nM mercury chloride (HgCl2), according to our previous study, followed by light-dark stimulation, a social assay, and color preference to examine the functionality of the visual system in relation to ASD-like behavior. Exposure of embryos to HgCl2 from gastrulation to hatching increased locomotor activity in the dark, reduced shoaling and exploratory behavior, and impaired color preference. Defects in microridges as the first barrier may serve as primary tools for HgCl2 toxicity affecting vision. Depletion of polyunsaturated fatty acids (PUFAs), linoleic acid, arachidonic acid (ARA), alpha-linoleic acid, docosahexaenoic acid (DHA), stearic acid, L-phenylalanine, isoleucine, L-lysine, and N-acetylputrescine, along with the increase of gamma-aminobutyric acid (GABA), sphingosine-1-phosphate, and citrulline assayed by liquid chromatography-mass spectrometry (LC-MS) suggest that these metabolites serve as biomarkers of retinal impairments that affect vision and behavior. Although suppression of adsl, shank3a, tsc1b, and nrxn1a gene expression was observed, among these tsc1b showed more positive correlation with ASD. Collectively, these results contribute new insights into the possible mechanism of mercury toxicity give rise to visual, cognitive, and social deficits in zebrafish.
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Affiliation(s)
- Noraini Abu Bakar
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Wan Norhamidah Wan Ibrahim
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Abdul Rahman Zulkiflli
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Nur Atikah Saleh Hodin
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Tae-Yoon Kim
- Department of Biology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Yee Soon Ling
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Mohd Mokrish Md Ajat
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400, Malaysia
| | - Khozirah Shaari
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Shamarina Shohaimi
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Nurrul Shaqinah Nasruddin
- Centre for Craniofacial Diagnostics, Faculty of Dentistry, Universiti Kebangsaan Malaysia (UKM), 50300 Kuala Lumpur, Malaysia
| | - Siti Munirah Mohd Faudzi
- Natural Medicines and Product Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon 34134, Republic of Korea.
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de los Santos C, Pastor JC, Calonge M. Mercury intoxication and ophthalmic involvement: An update review. FRONTIERS IN TOXICOLOGY 2023; 5:1148357. [PMID: 37063600 PMCID: PMC10102333 DOI: 10.3389/ftox.2023.1148357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
Human intoxication after mercury exposure is a rare condition that can cause severe damage to the central nervous, respiratory, cardiovascular, renal, gastrointestinal, skin, and visual systems and represents a major public health concern. Ophthalmic involvement includes impaired function of the extraocular muscles and the eyelids, as well as structural changes in the ocular surface, lens, retina, and optic nerve causing a potential irreversible damage to the visual system. Although, there are many pathways for poisoning depending on the mercury form, it has been suggested that tissue distribution does not differ in experimental animals when administered as mercury vapor, organic mercury, or inorganic mercury. Additionally, visual function alterations regarding central visual acuity, color discrimination, contrast sensitivity, visual field and electroretinogram responses have also been described widely. Nevertheless, there is still controversy about whether visual manifestations occur secondary to brain damage or as a direct affectation, and which ocular structure is primarily affected. Despite the use of some imaging techniques such as in vivo confocal microscopy of the cornea, optical coherence tomography (OCT) of the retina and optic nerve, and functional tests such as electroretinography has helped to solve in part this debate, further studies incorporating other imaging modalities such as autofluorescence, OCT angiography or adaptive optics retinal imaging are needed. This review aims to summarize the published structural and functional alterations found in the visual system of patients suffering from mercury intoxication.
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Affiliation(s)
- Cristian de los Santos
- Institute of Applied Ophthalmobiology (IOBA), Universidad de Valladolid, Valladolid, Spain
- *Correspondence: Cristian de los Santos,
| | - J. Carlos Pastor
- Institute of Applied Ophthalmobiology (IOBA), Universidad de Valladolid, Valladolid, Spain
- Centro en Red de Medicina Regenerativa y Terapia Celular. Junta de Castilla y León, Valladolid, Spain
| | - Margarita Calonge
- Institute of Applied Ophthalmobiology (IOBA), Universidad de Valladolid, Valladolid, Spain
- Centro en Red de Medicina Regenerativa y Terapia Celular. Junta de Castilla y León, Valladolid, Spain
- CIBER-BBN, Carlos III National Institute of Health, Madrid, Spain
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Tousignant B, Chatillon A, Philibert A, Da Silva J, Fillion M, Mergler D. Visual Characteristics of Adults with Long-Standing History of Dietary Exposure to Mercury in Grassy Narrows First Nation, Canada. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4827. [PMID: 36981736 PMCID: PMC10049103 DOI: 10.3390/ijerph20064827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/23/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Since the 1960s, Grassy Narrows First Nation (Ontario, Canada) has been exposed to methyl mercury (Hg) through fish consumption, resulting from industrial pollution of their territorial waters. This cross-sectional study describes the visual characteristics of adults with documented Hg exposure between 1970 and 1997. Oculo-visual examinations of 80 community members included visual acuity, automated visual fields, optical coherence tomography [OCT], color vision and contrast sensitivity. Median age was 57 years (IQR 51-63) and 55% of participants were women. Median visual acuity was 0.1 logMAR (Snellen 6/6.4; IQR 0-0.2). A total of 26% of participants presented a Visual Field Index inferior to 62%, and qualitative losses assessment showed concentric constriction (18%), end-stage concentric loss (18%), and complex defects (24%). On OCT, retinal nerve fiber layer scans showed 74% of participants within normal/green range. For color testing with the Hardy, Rand, and Rittler test, 40% presented at least one type of color defect, and with the Lanthony D-15 test, median color confusion index was 1.59 (IQR 1.33-1.96). Contrast sensitivity showed moderate loss for 83% of participants. These findings demonstrate important loss of visual field, color vision, and contrast sensitivity in older adults in a context of long-term exposure to Hg in Grassy Narrows First Nation.
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Affiliation(s)
- Benoit Tousignant
- School of Optometry, Université de Montréal, 3744 Jean-Brillant, Montreal, QC H3T 1P1, Canada
- Department of Social and Preventive Medicine, School of Public Health, Université de Montréal, 7101 Avenue du Parc, Montreal, QC H3N 1X9, Canada
| | - Annie Chatillon
- School of Optometry, Université de Montréal, 3744 Jean-Brillant, Montreal, QC H3T 1P1, Canada
| | - Aline Philibert
- Centre de Recherche Interdisciplinaire sur le Bien-être, la Santé, la Société et L’environnement (Cinbiose), Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada
| | - Judy Da Silva
- Grassy Narrows First Nation, General Delivery, Grassy Narrows, ON P0X 1B0, Canada
| | - Myriam Fillion
- Centre de Recherche Interdisciplinaire sur le Bien-être, la Santé, la Société et L’environnement (Cinbiose), Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada
- Département Science et Technologie, Université TÉLUQ, 5800, Rue Saint-Denis, Bureau 1105, Montréal, QC H2S 3L5, Canada
| | - Donna Mergler
- Centre de Recherche Interdisciplinaire sur le Bien-être, la Santé, la Société et L’environnement (Cinbiose), Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada
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10
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Potentially toxic elements in the brains of people with multiple sclerosis. Sci Rep 2023; 13:655. [PMID: 36635465 PMCID: PMC9837144 DOI: 10.1038/s41598-022-27169-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/26/2022] [Indexed: 01/14/2023] Open
Abstract
Potentially toxic elements such as lead and aluminium have been proposed to play a role in the pathogenesis of multiple sclerosis (MS), since their neurotoxic mechanisms mimic many of the pathogenetic processes in MS. We therefore examined the distribution of several potentially toxic elements in the autopsied brains of people with and without MS, using two methods of elemental bio-imaging. Toxicants detected in the locus ceruleus were used as indicators of past exposures. Autometallography of paraffin sections from multiple brain regions of 21 MS patients and 109 controls detected inorganic mercury, silver, or bismuth in many locus ceruleus neurons of both groups, and in widespread blood vessels, oligodendrocytes, astrocytes, and neurons of four MS patients and one control. Laser ablation-inductively coupled plasma-mass spectrometry imaging of pons paraffin sections from all MS patients and 12 controls showed that combinations of iron, silver, lead, aluminium, mercury, nickel, and bismuth were present more often in the locus ceruleus of MS patients and were located predominantly in white matter tracts. Based on these results, we propose that metal toxicants in locus ceruleus neurons weaken the blood-brain barrier, enabling multiple interacting toxicants to pass through blood vessels and enter astrocytes and oligodendroglia, leading to demyelination.
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11
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Navarro-Sempere A, García M, Rodrigues AS, Garcia PV, Camarinho R, Segovia Y. Occurrence of Volcanogenic Inorganic Mercury in Wild Mice Spinal Cord: Potential Health Implications. Biol Trace Elem Res 2022; 200:2838-2847. [PMID: 34415497 PMCID: PMC9132843 DOI: 10.1007/s12011-021-02890-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/13/2021] [Indexed: 11/25/2022]
Abstract
Mercury accumulation has been proposed as a toxic factor that causes neurodegenerative diseases. However, the hazardous health effects of gaseous elemental mercury exposure on the spinal cord in volcanic areas have not been reported previously in the literature. To evaluate the presence of volcanogenic inorganic mercury in the spinal cord, a study was carried out in São Miguel island (Azores, Portugal) by comparing the spinal cord of mice exposed chronically to an active volcanic environment (Furnas village) with individuals not exposed (Rabo de Peixe village), through the autometallographic silver enhancement histochemical method. Moreover, a morphometric and quantification analysis of the axons was carried out. Results exhibited mercury deposits at the lumbar level of the spinal cord in the specimens captured at the site with volcanic activity (Furnas village). A decrease in axon calibre and axonal atrophy was also observed in these specimens. Given that these are relevant hallmarks in the neurodegenerative pathologies, our results highlight the importance of the surveillance of the health of populations chronically exposed to active volcanic environments.
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Affiliation(s)
- A Navarro-Sempere
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain
| | - M García
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain
| | - A S Rodrigues
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- IVAR, Research Institute for Volcanology and Risk Assessment, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - P V Garcia
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- cE3c, Centre for Ecology, Evolution and Environmental Changes, and Azorean Biodiversity Group, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - R Camarinho
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- IVAR, Research Institute for Volcanology and Risk Assessment, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - Y Segovia
- Department of Biotechnology, Faculty of Science, University of Alicante, Apartado 99, 03080, Alicante, Spain.
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12
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Pamphlett R, Bishop DP. Mercury is present in neurons and oligodendrocytes in regions of the brain affected by Parkinson's disease and co-localises with Lewy bodies. PLoS One 2022; 17:e0262464. [PMID: 35015796 PMCID: PMC8752015 DOI: 10.1371/journal.pone.0262464] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/24/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Environmental toxicants are suspected to play a part in the pathogenesis of idiopathic Parkinson's disease (PD) and may underlie its increasing incidence. Mercury exposure in humans is common and is increasing due to accelerating levels of atmospheric mercury, and mercury damages cells via oxidative stress, cell membrane damage, and autoimmunity, mechanisms suspected in the pathogenesis of PD. We therefore compared the cellular distribution of mercury in the tissues of people with and without PD who had evidence of previous mercury exposure by mercury being present in their locus ceruleus neurons. MATERIALS AND METHODS Paraffin sections from the brain and general organs of two people with PD, two people without PD with a history of mercury exposure, and ten people without PD or known mercury exposure, were stained for inorganic mercury using autometallography, combined with immunostaining for a-synuclein and glial cells. All had mercury-containing neurons in locus ceruleus neurons. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to confirm the presence of mercury and to look for other potentially toxic elements. Autometallography-stained locus ceruleus paraffin sections were examined to compare the frequency of previous mercury exposure between 20 PD and 40 non-PD individuals. RESULTS In PD brains, autometallography-detected mercury was seen in neurons affected by the disease, such as those in the substantia nigra, motor cortex, striatum, thalamus, and cerebellum. Mercury was seen in oligodendrocytes in white and grey matter. Mercury often co-localised with Lewy bodies and neurites. A more restricted distribution of brain mercury was seen in people without PD (both with or without known mercury exposure), with no mercury present in the substantia nigra, striatum, or thalamus. The presence of autometallography-detected mercury in PD was confirmed with LA-ICP-MS, which demonstrated other potentially toxic metals in the locus ceruleus and high iron levels in white matter. Autometallography-detected mercury was found in locus ceruleus neurons in a similar proportion of PD (65%) and non-PD (63%) individuals. CONCLUSIONS In people with PD, mercury was found in neurons and oligodendrocytes in regions of the brain that are affected by the disease, and often co-localised with aggregated a-synuclein. Mercury in the motor cortex, thalamus and striatum could result in bradykinesia and rigidity, and mercury in the cerebellum could cause tremor. People without PD had a restricted uptake of mercury into the brain. The similar frequency of mercury in the locus ceruleus of people with and without PD suggests these two groups have had comparable previous mercury exposures but that PD brains have a greater predisposition to take up circulating mercury. While this post mortem study does not provide a direct link between mercury and idiopathic PD, it adds to the body of evidence that metal toxicants such as mercury play a role in the disease. A precautionary approach would be to reduce rising mercury levels in the atmosphere by limiting the burning of fossil fuels, which may be contributing to the increasing incidence of PD.
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Affiliation(s)
- Roger Pamphlett
- Sydney Medical School, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales, Australia
- Department of Neuropathology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
- * E-mail:
| | - David P. Bishop
- Elemental Bio-Imaging Facility, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
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13
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Ke T, Tinkov AA, Skalny AV, Bowman AB, Rocha JBT, Santamaria A, Aschner M. Developmental exposure to methylmercury and ADHD, a literature review of epigenetic studies. ENVIRONMENTAL EPIGENETICS 2021; 7:dvab014. [PMID: 34881051 PMCID: PMC8648069 DOI: 10.1093/eep/dvab014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/20/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that affects the competence of academic performance and social wellness in children and adults. The causes of ADHD are unclear. Both genetic and environmental factors contribute to the development of ADHD. The behavioral impairments in ADHD are associated with epigenetic changes in genes that are important for neurodevelopment. Among environmental causes of ADHD, the neurotoxin methylmercury (MeHg) is associated with an increased risk for ADHD. Developing children are susceptible to neurotoxic effects of prenatal MeHg exposure. Human epidemiology studies have shown that prenatal MeHg exposure could invoke epigenetic changes in genes that are involved in ADHD. In addition, the pathogenesis of ADHD involves dopaminergic system, which is a target of developmental MeHg exposure. MeHg-induced alterations in the dopaminergic system have a profound impact on behavioral functions in adults. As a trace level of MeHg (around nM) can induce long-lasting behavioral alterations, potential mechanisms of MeHg-induced functional changes in the dopaminergic system may involve epigenetic mechanisms. Here, we review the relevant evidence on developmental MeHg exposures and the risk for ADHD. We also point out research gaps in understanding environmental causes of ADHD.
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Affiliation(s)
- Tao Ke
- **Correspondence address. Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Forchheimer Building, Room 209, Bronx, NY 10461, USA. Tel: +1 718 430 4047; Fax: +1 718 430 8922; E-mail:
| | - Alexey A Tinkov
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow 119435, Russia
- Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, Yaroslavl 150003, Russia
| | - Antoly V Skalny
- World-Class Research Center “Digital Biodesign and Personalized Healthcare”, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow 119435, Russia
- Laboratory of Medical Elementology, K.G. Razumovsky Moscow State University of Technologies and Management, Moscow 109004, Russia
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, USA
| | - Joao B T Rocha
- Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS 97105-900, Brazil
| | - Abel Santamaria
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía, Mexico City 14269, Mexico
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Forchheimer Building, Room 209, Bronx, NY 10461, USA
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14
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Camarinho R, Navarro-Sempere A, Garcia PV, García M, Segovia Y, Rodrigues AS. Chronic exposure to volcanic gaseous elemental mercury: using wild Mus musculus to unveil its uptake and fate. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:4863-4867. [PMID: 33860889 DOI: 10.1007/s10653-021-00924-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
Volcanoes are a natural source of gaseous elemental mercury (GEM) (Hg0). Monitoring GEM releases of volcanic origin has been widely studied; however, few studies have been performed about the biomonitoring of species exposed to GEM, rendering an unknown risk to the worldwide populations living in the vicinity of an active volcano. In this pilot study, we used Mus musculus as a bioindicator species to understand to what extent lungs are the main route of mercury uptake in populations chronically exposed to active volcanic environments. Autometallographic silver protocol was used to detect mercury deposits in the histological lung slides. Abundant mercury deposits were found in the lungs of specimens captured at the site with volcanic activity (Furnas Village, S. Miguel Island-Azores). The presence of mercury in the lungs could represent not only hazardous effects to the lung itself but also to other tissues and organs, such as brain and kidneys. This study confirms that the main uptake route for GEM is the lungs and that, even at very low concentrations in the environment, a chronic exposure to Hg0 results in its bioaccumulation in the lung tissue. These results reinforce that biomonitoring studies should be combined with monitoring classical approaches in order to better characterize the risks of exposure to Hg0 in volcanic environments.
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Affiliation(s)
- R Camarinho
- Faculdade de Ciências E Tecnologia, Universidade Dos Açores, Rua da Mãe de Deus, Apartado 1422, 9501-801, Ponta Delgada, Açores, Portugal
- University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - A Navarro-Sempere
- Department of Biotechnology, University of Alicante, Apart 99, 03080, Alicante, Spain
| | - P V Garcia
- Faculdade de Ciências E Tecnologia, Universidade Dos Açores, Rua da Mãe de Deus, Apartado 1422, 9501-801, Ponta Delgada, Açores, Portugal
- Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, University of the Azores, 9501-801, Ponta Delgada, Azores, Portugal
| | - M García
- Department of Biotechnology, University of Alicante, Apart 99, 03080, Alicante, Spain
| | - Y Segovia
- Department of Biotechnology, University of Alicante, Apart 99, 03080, Alicante, Spain
| | - A S Rodrigues
- Faculdade de Ciências E Tecnologia, Universidade Dos Açores, Rua da Mãe de Deus, Apartado 1422, 9501-801, Ponta Delgada, Açores, Portugal.
- University of the Azores, 9501-801, Ponta Delgada, Portugal.
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15
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Tu R, Zhang C, Feng L, Wang H, Wang W, Li P. Impact of selenium on cerebellar injury and mRNA expression in offspring of rat exposed to methylmercury. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 223:112584. [PMID: 34365210 DOI: 10.1016/j.ecoenv.2021.112584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/20/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
During the fetal development stage, the Central Nervous System (CNS) is particularly sensitive to methylmercury (MeHg). However, the mechanism underlying the antagonistic effect of selenium (Se) on MeHg toxicity is still not fully understood. In this study, female rat models with MeHg and Se co-exposure were developed. Pathological changes in the cerebellum and differential mRNA expression profiles in offspring rats were studied. In the MeHg-exposed group, a large number of Purkinje cells showed pathological changes and mitochondria were significantly swollen; co-exposure with Se significantly improved the structure and organization of the cerebellum. In total, 378 differentially expressed genes (DEGs) (including 284 up-regulated genes and 94 down-regulated genes) in the cerebellum of the MeHg-exposed group and 210 DEGs (including 84 up-regulated genes and 126 down-regulated genes) in the cerebellum of the MeHg+Se co-exposed group were identified. The genes involved in neurotransmitter synthesis and release and calcium ion balance in the cerebellum were significantly up-regulated in the MeHg-exposed group. These genes in the MeHg+Se co-exposed group were not changed or down-regulated. These findings demonstrate that the neurotoxicity caused by MeHg exposure is related to the up-regulation of multiple genes in the nerve signal transduction and calcium ion signal pathways, which are closely related to impairments in cell apoptosis and learning and memory. Supplementation with Se can mitigate the changes to related genes and protect neurons in the mammalian brain (especially the developing cerebellum) from MeHg toxicity. Se provides a potential intervention strategy for MeHg toxicity.
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Affiliation(s)
- Rui Tu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; Key Laboratory of Environmental Pollution Monitoring and Disease Control/School of Public Health, Guizhou Medical University, Guiyang 550025, China; Division of Infection Management, Guiyang First People's Hospital, Guiyang 550000, China
| | - Chanchan Zhang
- Key Laboratory of Environmental Pollution Monitoring and Disease Control/School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Ling Feng
- Key Laboratory of Environmental Pollution Monitoring and Disease Control/School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Huiqun Wang
- Key Laboratory of Environmental Pollution Monitoring and Disease Control/School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Wenjuan Wang
- Key Laboratory of Environmental Pollution Monitoring and Disease Control/School of Public Health, Guizhou Medical University, Guiyang 550025, China.
| | - Ping Li
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
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16
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The prevalence of inorganic mercury in human cells increases during aging but decreases in the very old. Sci Rep 2021; 11:16714. [PMID: 34408264 PMCID: PMC8373952 DOI: 10.1038/s41598-021-96359-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 07/30/2021] [Indexed: 11/09/2022] Open
Abstract
Successful aging is likely to involve both genetic and environmental factors, but environmental toxicants that accelerate aging are not known. Human exposure to mercury is common, and mercury has genotoxic, autoimmune, and free radical effects which could contribute to age-related disorders. The presence of inorganic mercury was therefore assessed in the organs of 170 people aged 1-104 years to determine the prevalence of mercury in human tissues at different ages. Mercury was found commonly in cells of the brain, kidney, thyroid, anterior pituitary, adrenal medulla and pancreas. The prevalence of mercury in these organs increased during aging but decreased in people aged over 80 years. People with mercury in one organ usually also had mercury in several others. In conclusion, the prevalence of inorganic mercury in human organs increases with age. The relative lack of tissue mercury in the very old could account for the flattened mortality rate and reduced incidence of cancer in this advanced age group. Since mercury may accelerate aging, efforts to reduce atmospheric mercury pollution could improve the chances of future successful aging.
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17
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Pigatto P, Guzzi G. Bilateral Optic Disc Edema in a Patient with Lead Poisoning. J Ophthalmic Vis Res 2021; 16:524-525. [PMID: 34394882 PMCID: PMC8358748 DOI: 10.18502/jovr.v16i3.9450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 04/13/2021] [Indexed: 11/25/2022] Open
Affiliation(s)
- Paolo Pigatto
- Clinical Dermatology, IRCCS Istituto Ortopedico Galeazzi, Milano MI, Italy.,Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Gianpaolo Guzzi
- Italian Association for Metals and Biocompatibility Research - AIRMEB, Milan, Italy
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18
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Pamphlett R, Doble PA, Bishop DP. The Prevalence of Inorganic Mercury in Human Kidneys Suggests a Role for Toxic Metals in Essential Hypertension. TOXICS 2021; 9:67. [PMID: 33801008 PMCID: PMC8004013 DOI: 10.3390/toxics9030067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 02/06/2023]
Abstract
The kidney plays a dominant role in the pathogenesis of essential hypertension, but the initial pathogenic events in the kidney leading to hypertension are not known. Exposure to mercury has been linked to many diseases including hypertension in epidemiological and experimental studies, so we studied the distribution and prevalence of mercury in the human kidney. Paraffin sections of kidneys were available from 129 people ranging in age from 1 to 104 years who had forensic/coronial autopsies. One individual had injected himself with metallic mercury, the other 128 were from varied clinicopathological backgrounds without known exposure to mercury. Sections were stained for inorganic mercury using autometallography. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used on six samples to confirm the presence of autometallography-detected mercury and to look for other toxic metals. In the 128 people without known mercury exposure, mercury was found in: (1) proximal tubules of the cortex and Henle thin loops of the medulla, in 25% of kidneys (and also in the man who injected himself with mercury), (2) proximal tubules only in 16% of kidneys, and (3) Henle thin loops only in 23% of kidneys. The age-related proportion of people who had any mercury in their kidney was 0% at 1-20 years, 66% at 21-40 years, 77% at 41-60 years, 84% at 61-80 years, and 64% at 81-104 years. LA-ICP-MS confirmed the presence of mercury in samples staining with autometallography and showed cadmium, lead, iron, nickel, and silver in some kidneys. In conclusion, mercury is found commonly in the adult human kidney, where it appears to accumulate in proximal tubules and Henle thin loops until an advanced age. Dysfunctions of both these cortical and medullary regions have been implicated in the pathogenesis of essential hypertension, so these findings suggest that further studies of the effects of mercury on blood pressure are warranted.
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Affiliation(s)
- Roger Pamphlett
- Discipline of Pathology, Brain and Mind Centre, Sydney Medical School, The University of Sydney, Sydney 2050, Australia
- Department of Neuropathology, Royal Prince Alfred Hospital, Sydney 2050, Australia
| | - Philip A. Doble
- Elemental Bio-Imaging Facility, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney 2007, Australia; (P.A.D.); (D.P.B.)
| | - David P. Bishop
- Elemental Bio-Imaging Facility, School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney 2007, Australia; (P.A.D.); (D.P.B.)
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19
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Li M, Yang T, Gao L, Xu H. An inadvertent issue of human retina exposure to endocrine disrupting chemicals: A safety assessment. CHEMOSPHERE 2021; 264:128484. [PMID: 33022499 DOI: 10.1016/j.chemosphere.2020.128484] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/07/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Endocrine disrupting chemicals (EDCs) are a group of chemical compounds that present a considerable public health problem due to their pervasiveness and associations with chronic diseases. EDCs can interrupt the endocrine system and interfere with hormone homeostasis, leading to abnormalities in human physiology. Much attention has been focused on the adverse effects EDCs have on the reproductive system, neurogenesis, neuroendocrine system, and thyroid dysfunction. The eye is usually directly exposed to the surrounding environment; however, the influences of EDCs on the eye have received comparatively little attention. Ocular diseases, such as ocular surface diseases and retinal diseases, have been implicated in hormone deficiency or excess. Epidemiologic studies have shown that EDC exposure not only causes ocular surface disorders, such as dry eye, but also associates with visual deficits and retinopathy. EDCs can pass through the human blood-retinal barrier and enter the neural retina, and can then accumulate in the retina. The retina is an embryologic extension of the central nervous system, and is extremely sensitive and vulnerable to EDCs that could be passed across the placenta during critical periods of retinal development. Subtle alterations in the retinal development process usually result in profound immediate, long-term, and delayed effects late in life. This review, based on extensive literature survey, briefly summarizes the current knowledge about the impact of representative manufactured EDCs on retinal toxicity, including retinal structure alterations and dysfunction. We also highlight the potential mechanism of action of EDCs on the retina, and the predictive retinal models of EDC exposure.
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Affiliation(s)
- Minghui Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Tian Yang
- Department of Cold Environmental Medicine, College of High Altitude Military Medicine, Third Military Medical University (Army Medical University), Chongqing, China
| | - Lixiong Gao
- Department of Ophthalmology, Third Medical Center of PLA General Hospital, Beijing, China
| | - Haiwei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China.
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20
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Navarro-Sempere A, Segovia Y, Rodrigues AS, Garcia PV, Camarinho R, García M. First record on mercury accumulation in mice brain living in active volcanic environments: a cytochemical approach. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2021; 43:171-183. [PMID: 32794111 DOI: 10.1007/s10653-020-00690-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
The health effects of mercury vapor exposure on the brain in volcanic areas have not been previously addressed in the literature. However, 10% of the worldwide population inhabits in the vicinity of an active volcano, which are natural sources of elemental mercury emission. To evaluate the presence of mercury compounds in the brain after chronic exposure to volcanogenic mercury vapor, a histochemical study, using autometallographic silver, was carried out to compare the brain of mice chronically exposed to an active volcanic environment (Furnas village, Azores, Portugal) with those not exposed (Rabo de Peixe village, Azores, Portugal). Results demonstrated several mercury deposits in blood vessels, white matter and some cells of the hippocampus in the brain of chronically exposed mice. Our results highlight that chronic exposure to an active volcanic environment results in brain mercury accumulation, raising an alert regarding potential human health risks. These findings support the hypothesis that mercury exposure can be a risk factor in causing neurodegenerative diseases in the inhabitants of volcanically active areas.
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Affiliation(s)
- A Navarro-Sempere
- Department of Biotechnology, University of Alicante, Apartado 99, 03080, Alicante, Spain
| | - Y Segovia
- Department of Biotechnology, University of Alicante, Apartado 99, 03080, Alicante, Spain.
| | - A S Rodrigues
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- IVAR, Research Institute for Volcanology and Risk Assessment, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - P V Garcia
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- cE3c, Centre for Ecology, Evolution and Environmental Changes, and Azorean Biodiversity Group, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - R Camarinho
- Faculty of Sciences and Technology, University of the Azores, 9501-801, Ponta Delgada, Portugal
- IVAR, Research Institute for Volcanology and Risk Assessment, University of the Azores, 9501-801, Ponta Delgada, Portugal
| | - M García
- Department of Biotechnology, University of Alicante, Apartado 99, 03080, Alicante, Spain
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The distribution of toxic metals in the human retina and optic nerve head: Implications for age-related macular degeneration. PLoS One 2020; 15:e0241054. [PMID: 33119674 PMCID: PMC7595417 DOI: 10.1371/journal.pone.0241054] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 10/07/2020] [Indexed: 01/14/2023] Open
Abstract
Objective Toxic metals are suspected to play a role in the pathogenesis of age-related macular degeneration. However, difficulties in detecting the presence of multiple toxic metals within the intact human retina, and in separating primary metal toxicity from the secondary uptake of metals in damaged tissue, have hindered progress in this field. We therefore looked for the presence of several toxic metals in the posterior segment of normal adult eyes using elemental bioimaging. Methods Paraffin sections of the posterior segment of the eye from seven tissue donors (age range 54–74 years) to an eye bank were examined for toxic metals in situ using laser ablation-inductively coupled plasma-mass spectrometry, a technique that detects multiple elements in tissues, as well as the histochemical technique of autometallography that demonstrates inorganic mercury, silver, and bismuth. No donor had a visual impairment, and no significant retinal abnormalities were seen on post mortem fundoscopy and histology. Results Metals found by laser ablation-inductively coupled plasma-mass spectrometry in the retinal pigment epithelium and choriocapillaris were lead (n = 7), nickel (n = 7), iron (n = 7), cadmium (n = 6), mercury (n = 6), bismuth (n = 5), aluminium (n = 3), and silver (n = 1). In the neural retina, mercury was present in six samples, and iron in one. Metals detected in the optic nerve head were iron (N = 7), mercury (N = 7), nickel (N = 4), and aluminium (N = 1). No gold or chromium was seen. Autometallography demonstrated probable inorganic mercury in the retinal pigment epithelium of one donor. Conclusion Several toxic metals are taken up by the human retina and optic nerve head. Injury to the retinal pigment epithelium from toxic metals could damage the neuroprotective functions of the retinal pigment epithelium and allow toxic metals to enter the outer neural retina. These findings support the hypothesis that accumulations of toxic metals in the retina could contribute to the pathogenesis of age-related macular degeneration.
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