1
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von Mikecz A. Elegant Nematodes Improve Our Understanding of Human Neuronal Diseases, the Role of Pollutants and Strategies of Resilience. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16755-16763. [PMID: 37874738 PMCID: PMC10634345 DOI: 10.1021/acs.est.3c04580] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
The prevalence of neurodegenerative disorders such as Alzheimer's and Parkinson's disease are rising globally. The role of environmental pollution in neurodegeneration is largely unknown. Thus, this perspective advocates exposome research in C. elegans models of human diseases. The models express amyloid proteins such as Aβ, recapitulate the degeneration of specifically vulnerable neurons and allow for correlated neurobehavioral phenotyping throughout the entire life span of the nematode. Neurobehavioral traits like locomotion gaits, rigidity, or cognitive decline are quantifiable and carefully mimic key aspects of the human diseases. Underlying molecular pathways of neurodegeneration are elucidated in pollutant-exposed C. elegans Alzheimer's or Parkinson's models by transcriptomics (RNA-seq), mass spectrometry-based proteomics and omics addressing other biochemical traits. Validation of the identified disease pathways can be achieved by genome-wide association studies in matching human cohorts. A consistent One Health approach includes isolation of nematodes from contaminated sites and their comparative investigation by imaging, neurobehavioral profiling and single worm proteomics. C. elegans models of neurodegenerative diseases are likewise well-suited for high throughput methods that provide a promising strategy to identify resilience pathways of neurosafety and keep up with the number of pollutants, nonchemical exposome factors, and their interactions.
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Affiliation(s)
- Anna von Mikecz
- IUF − Leibniz Research Institute
of Environmental Medicine GmbH, Auf’m Hennekamp 50, 40225 Duesseldorf, Germany
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2
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Berntsson E, Sardis M, Noormägi A, Jarvet J, Roos PM, Tõugu V, Gräslund A, Palumaa P, Wärmländer SKTS. Mercury Ion Binding to Apolipoprotein E Variants ApoE2, ApoE3, and ApoE4: Similar Binding Affinities but Different Structure Induction Effects. ACS OMEGA 2022; 7:28924-28931. [PMID: 36033665 PMCID: PMC9404194 DOI: 10.1021/acsomega.2c02254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Mercury intoxication typically produces more severe outcomes in people with the APOE-ε4 gene, which codes for the ApoE4 variant of apolipoprotein E, compared to individuals with the APOE-ε2 and APOE-ε3 genes. Why the APOE-ε4 allele is a risk factor in mercury exposure remains unknown. One proposed possibility is that the ApoE protein could be involved in clearing of heavy metals, where the ApoE4 protein might perform this task worse than the ApoE2 and ApoE3 variants. Here, we used fluorescence and circular dichroism spectroscopies to characterize the in vitro interactions of the three different ApoE variants with Hg(I) and Hg(II) ions. Hg(I) ions displayed weak binding to all ApoE variants and induced virtually no structural changes. Thus, Hg(I) ions appear to have no biologically relevant interactions with the ApoE protein. Hg(II) ions displayed stronger and very similar binding affinities for all three ApoE isoforms, with K D values of 4.6 μM for ApoE2, 4.9 μM for ApoE3, and 4.3 μM for ApoE4. Binding of Hg(II) ions also induced changes in ApoE superhelicity, that is, altered coil-coil interactions, which might modify the protein function. As these structural changes were most pronounced in the ApoE4 protein, they could be related to the APOE-ε4 gene being a risk factor in mercury toxicity.
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Affiliation(s)
- Elina Berntsson
- Department
of Chemistry and Biotechnology, Tallinn
University of Technology, 12618 Tallinn, Estonia
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
| | - Merlin Sardis
- Department
of Chemistry and Biotechnology, Tallinn
University of Technology, 12618 Tallinn, Estonia
| | - Andra Noormägi
- Department
of Chemistry and Biotechnology, Tallinn
University of Technology, 12618 Tallinn, Estonia
| | - Jüri Jarvet
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
- The
National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia
- CellPept
Sweden AB, Kvarngatan
10B, 118 47 Stockholm, Sweden
| | - Per M. Roos
- Institute
of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department
of Clinical Physiology, Capio Saint Göran
Hospital, 112 19 Stockholm, Sweden
| | - Vello Tõugu
- Department
of Chemistry and Biotechnology, Tallinn
University of Technology, 12618 Tallinn, Estonia
| | - Astrid Gräslund
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
- CellPept
Sweden AB, Kvarngatan
10B, 118 47 Stockholm, Sweden
| | - Peep Palumaa
- Department
of Chemistry and Biotechnology, Tallinn
University of Technology, 12618 Tallinn, Estonia
| | - Sebastian K. T. S. Wärmländer
- Department
of Biochemistry and Biophysics, Stockholm
University, 106 91 Stockholm, Sweden
- CellPept
Sweden AB, Kvarngatan
10B, 118 47 Stockholm, Sweden
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3
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Scharf A, Limke A, Guehrs KH, von Mikecz A. Pollutants corrupt resilience pathways of aging in the nematode C. elegans. iScience 2022; 25:105027. [PMID: 36117993 PMCID: PMC9475316 DOI: 10.1016/j.isci.2022.105027] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/06/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
Delaying aging while prolonging health and lifespan is a major goal in aging research. One promising strategy is to focus on reducing negative interventions such as pollution and their accelerating effect on age-related degeneration and disease. Here, we used the short-lived model organism C. elegans to analyze whether two candidate pollutants corrupt general aging pathways. We show that the emergent pollutant silica nanoparticles (NPs) and the classic xenobiotic inorganic mercury reduce lifespan and cause a premature protein aggregation phenotype. Comparative mass spectrometry revealed that increased insolubility of proteins with important functions in proteostasis is a shared phenotype of intrinsic- and pollution-induced aging supporting the hypothesis that proteostasis is a central resilience pathway controlling lifespan and aging. The presented data demonstrate that pollutants corrupt intrinsic aging pathways. Reducing pollution is, therefore, an important step to increasing healthy aging and prolonging life expectancies on a population level in humans and animals. Two candidate pollutants, iHg, and nanosilica, reduce lifespans in C. elegans iHg and silica NPs induce premature aggregation phenotypes in C. elegans Pollutants-induced premature and intrinsic aging share nine super aggregation proteins Reducing pollution is important for an effective strategy to support healthy aging
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4
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Flynn LL, Li R, Pitout IL, Aung-Htut MT, Larcher LM, Cooper JAL, Greer KL, Hubbard A, Griffiths L, Bond CS, Wilton SD, Fox AH, Fletcher S. Single Stranded Fully Modified-Phosphorothioate Oligonucleotides can Induce Structured Nuclear Inclusions, Alter Nuclear Protein Localization and Disturb the Transcriptome In Vitro. Front Genet 2022; 13:791416. [PMID: 35464859 PMCID: PMC9019733 DOI: 10.3389/fgene.2022.791416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 03/02/2022] [Indexed: 01/12/2023] Open
Abstract
Oligonucleotides and nucleic acid analogues that alter gene expression are now showing therapeutic promise in human disease. Whilst the modification of synthetic nucleic acids to protect against nuclease degradation and to influence drug function is common practice, such modifications may also confer unexpected physicochemical and biological properties. Gapmer mixed-modified and DNA oligonucleotides on a phosphorothioate backbone can bind non-specifically to intracellular proteins to form a variety of toxic inclusions, driven by the phosphorothioate linkages, but also influenced by the oligonucleotide sequence. Recently, the non-antisense or other off-target effects of 2′ O- fully modified phosphorothioate linkage oligonucleotides are becoming better understood. Here, we report chemistry-specific effects of oligonucleotides composed of modified or unmodified bases, with phosphorothioate linkages, on subnuclear organelles and show altered distribution of nuclear proteins, the appearance of highly stable and strikingly structured nuclear inclusions, and disturbed RNA processing in primary human fibroblasts and other cultured cells. Phosphodiester, phosphorodiamidate morpholino oligomers, and annealed complimentary phosphorothioate oligomer duplexes elicited no such consequences. Disruption of subnuclear structures and proteins elicit severe phenotypic disturbances, revealed by transcriptomic analysis of transfected fibroblasts exhibiting such disruption. Our data add to the growing body of evidence of off-target effects of some phosphorothioate nucleic acid drugs in primary cells and suggest alternative approaches to mitigate these effects.
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Affiliation(s)
- Loren L Flynn
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,Perron Institute, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia.,Black Swan Pharmaceuticals, Wake Forest, NC, United States
| | - Ruohan Li
- Cell and Tissue Therapies WA, Royal Perth Hospital, Perth, WA, Australia.,School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Ianthe L Pitout
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,PYC Therapeutics, Nedlands, WA, Australia
| | - May T Aung-Htut
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,Perron Institute, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia
| | - Leon M Larcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Jack A L Cooper
- School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Kane L Greer
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,Perron Institute, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia
| | - Alysia Hubbard
- Centre for Microscopy, Characterization and Analysis, The University of Western Australia, Nedlands, WA, Australia
| | - Lisa Griffiths
- Anatomical Pathology, Department of Health, Nedlands, WA, Australia
| | - Charles S Bond
- School of Molecular Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,Perron Institute, Nedlands, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia
| | - Archa H Fox
- School of Human Sciences, The University of Western Australia, Nedlands, WA, Australia.,School of Molecular Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Sue Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,Centre for Neuromuscular and Neurological Disorders, The University of Western Australia, Nedlands, WA, Australia.,PYC Therapeutics, Nedlands, WA, Australia
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5
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Lettieri G, Notariale R, Carusone N, Giarra A, Trifuoggi M, Manna C, Piscopo M. New Insights into Alterations in PL Proteins Affecting Their Binding to DNA after Exposure of Mytilus galloprovincialis to Mercury-A Possible Risk to Sperm Chromatin Structure? Int J Mol Sci 2021; 22:5893. [PMID: 34072703 PMCID: PMC8198333 DOI: 10.3390/ijms22115893] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/14/2021] [Accepted: 05/28/2021] [Indexed: 12/13/2022] Open
Abstract
Mercury (Hg) is a highly toxic and widespread pollutant. We previously reported that the exposure of Mytilus galloprovincialis for 24 h to doses of HgCl2 similar to those found in seawater (range 1-100 pM) produced alterations in the properties of protamine-like (PL) proteins that rendered them unable to bind and protect DNA from oxidative damage. In the present work, to deepen our studies, we analyzed PL proteins by turbidimetry and fluorescence spectroscopy and performed salt-induced release analyses of these proteins from sperm nuclei after the exposure of mussels to HgCl2 at the same doses. Turbidity assays indicated that mercury, at these doses, induced PL protein aggregates, whereas fluorescence spectroscopy measurements showed mercury-induced conformational changes. Indeed, the mobility of the PLII band changed in sodium dodecyl sulphate-polyacrylamide gel electrophoresis, particularly after exposure to 10-pM HgCl2, confirming the mercury-induced structural rearrangement. Finally, exposure to HgCl2 at all doses produced alterations in PL-DNA binding, detectable by DNA absorption spectra after the PL protein addition and by a decreased release of PLII and PLIII from the sperm nuclei. In conclusion, in this paper, we reported Hg-induced PL protein alterations that could adversely affect mussel reproductive activity, providing an insight into the molecular mechanism of Hg-related infertility.
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Affiliation(s)
- Gennaro Lettieri
- Department of Biology, University of Naples Federico II, Via Cinthia, 21, 80126 Naples, Italy; (G.L.); (N.C.)
| | - Rosaria Notariale
- Department of Precision Medicine, School of Medicine, University of Campania “Luigi Vanvitelli”, via Luigi de Crecchio, 80138 Naples, Italy; (R.N.); (C.M.)
| | - Nadia Carusone
- Department of Biology, University of Naples Federico II, Via Cinthia, 21, 80126 Naples, Italy; (G.L.); (N.C.)
| | - Antonella Giarra
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia, 21, 80126 Naples, Italy; (A.G.); (M.T.)
| | - Marco Trifuoggi
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia, 21, 80126 Naples, Italy; (A.G.); (M.T.)
| | - Caterina Manna
- Department of Precision Medicine, School of Medicine, University of Campania “Luigi Vanvitelli”, via Luigi de Crecchio, 80138 Naples, Italy; (R.N.); (C.M.)
| | - Marina Piscopo
- Department of Biology, University of Naples Federico II, Via Cinthia, 21, 80126 Naples, Italy; (G.L.); (N.C.)
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6
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Effects of Airborne Nanoparticles on the Nervous System: Amyloid Protein Aggregation, Neurodegeneration and Neurodegenerative Diseases. NANOMATERIALS 2020; 10:nano10071349. [PMID: 32664217 PMCID: PMC7407104 DOI: 10.3390/nano10071349] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 01/18/2023]
Abstract
How the environment contributes to neurodegenerative diseases such as Alzheimer’s is not well understood. In recent years, science has found augmenting evidence that nano-sized particles generated by transport (e.g., fuel combustion, tire wear and brake wear) may promote Alzheimer’s disease (AD). Individuals residing close to busy roads are at higher risk of developing AD, and nanomaterials that are specifically generated by traffic-related processes have been detected in human brains. Since AD represents a neurodegenerative disease characterized by amyloid protein aggregation, this review summarizes our current knowledge on the amyloid-generating propensity of traffic-related nanomaterials. Certain nanoparticles induce the amyloid aggregation of otherwise soluble proteins in in vitro laboratory settings, cultured neuronal cells and vertebrate or invertebrate animal models. We discuss the challenges for future studies, namely, strategies to connect the wet laboratory with the epidemiological data in order to elucidate the molecular bio-interactions of airborne nanomaterials and their effects on human health.
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7
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Wallin C, Friedemann M, Sholts SB, Noormägi A, Svantesson T, Jarvet J, Roos PM, Palumaa P, Gräslund A, Wärmländer SKTS. Mercury and Alzheimer's Disease: Hg(II) Ions Display Specific Binding to the Amyloid-β Peptide and Hinder Its Fibrillization. Biomolecules 2019; 10:E44. [PMID: 31892131 PMCID: PMC7022868 DOI: 10.3390/biom10010044] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 02/07/2023] Open
Abstract
Brains and blood of Alzheimer's disease (AD) patients have shown elevated mercury concentrations, but potential involvement of mercury exposure in AD pathogenesis has not been studied at the molecular level. The pathological hallmark of AD brains is deposition of amyloid plaques, consisting mainly of amyloid-β (Aβ) peptides aggregated into amyloid fibrils. Aβ peptide fibrillization is known to be modulated by metal ions such as Cu(II) and Zn(II). Here, we study in vitro the interactions between Aβ peptides and Hg(II) ions by multiple biophysical techniques. Fluorescence spectroscopy and atomic force microscopy (AFM) show that Hg(II) ions have a concentration-dependent inhibiting effect on Aβ fibrillization: at a 1:1 Aβ·Hg(II) ratio only non-fibrillar Aβ aggregates are formed. NMR spectroscopy shows that Hg(II) ions interact with the N-terminal region of Aβ(1-40) with a micromolar affinity, likely via a binding mode similar to that for Cu(II) and Zn(II) ions, i.e., mainly via the histidine residues His6, His13, and His14. Thus, together with Cu(II), Fe(II), Mn(II), Pb(IV), and Zn(II) ions, Hg(II) belongs to a family of metal ions that display residue-specific binding interactions with Aβ peptides and modulate their aggregation processes.
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Affiliation(s)
- Cecilia Wallin
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; (C.W.); (T.S.); (J.J.); (A.G.)
| | - Merlin Friedemann
- Department of Chemistry and Biotechnology, Tallinn University of Technology, 19086 Tallinn, Estonia; (M.F.); (A.N.); (P.P.)
| | - Sabrina B. Sholts
- Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA;
| | - Andra Noormägi
- Department of Chemistry and Biotechnology, Tallinn University of Technology, 19086 Tallinn, Estonia; (M.F.); (A.N.); (P.P.)
| | - Teodor Svantesson
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; (C.W.); (T.S.); (J.J.); (A.G.)
| | - Jüri Jarvet
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; (C.W.); (T.S.); (J.J.); (A.G.)
- The National Institute of Chemical Physics and Biophysics, 12618 Tallinn, Estonia
| | - Per M. Roos
- Institute of Environmental Medicine, Karolinska Institutet, 16765 Stockholm, Sweden;
- Department of Clinical Physiology, Capio St. Göran Hospital, 11219 Stockholm, Sweden
| | - Peep Palumaa
- Department of Chemistry and Biotechnology, Tallinn University of Technology, 19086 Tallinn, Estonia; (M.F.); (A.N.); (P.P.)
| | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; (C.W.); (T.S.); (J.J.); (A.G.)
| | - Sebastian K. T. S. Wärmländer
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; (C.W.); (T.S.); (J.J.); (A.G.)
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8
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Insights into the Potential Role of Mercury in Alzheimer's Disease. J Mol Neurosci 2019; 67:511-533. [PMID: 30877448 DOI: 10.1007/s12031-019-01274-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/30/2019] [Indexed: 12/18/2022]
Abstract
Mercury (Hg), which is a non-essential element, is considered a highly toxic pollutant for biological systems even when present at trace levels. Elevated Hg exposure with the growing release of atmospheric pollutant Hg and rising accumulations of mono-methylmercury (highly neurotoxic) in seafood products have increased its toxic potential for humans. This review aims to highlight the potential relationship between Hg exposure and Alzheimer's disease (AD), based on the existing literature in the field. Recent reports have hypothesized that Hg exposure could increase the potential risk of developing AD. Also, AD is known as a complex neurological disorder with increased amounts of both extracellular neuritic plaques and intracellular neurofibrillary tangles, which may also be related to lifestyle and genetic variables. Research reports on AD and relationships between Hg and AD indicate that neurotransmitters such as serotonin, acetylcholine, dopamine, norepinephrine, and glutamate are dysregulated in patients with AD. Many researchers have suggested that AD patients should be evaluated for Hg exposure and toxicity. Some authors suggest further exploration of the Hg concentrations in AD patients. Dysfunctional signaling pathways in AD and Hg exposure appear to be interlinked with some driving factors such as arachidonic acid, homocysteine, dehydroepiandrosterone (DHEA) sulfate, hydrogen peroxide, glucosamine glycans, glutathione, acetyl-L carnitine, melatonin, and HDL. This evidence suggests the need for a better understanding of the relationship between AD and Hg exposure, and potential mechanisms underlying the effects of Hg exposure on regional brain functions. Also, further studies evaluating brain functions are needed to explore the long-term effects of subclinical and untreated Hg toxicity on the brain function of AD patients.
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9
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Chan MC, Bautista E, Alvarado-Cruz I, Quintanilla-Vega B, Segovia J. Inorganic mercury prevents the differentiation of SH-SY5Y cells: Amyloid precursor protein, microtubule associated proteins and ROS as potential targets. J Trace Elem Med Biol 2017; 41:119-128. [PMID: 28209268 DOI: 10.1016/j.jtemb.2017.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/16/2017] [Accepted: 02/05/2017] [Indexed: 10/20/2022]
Abstract
Exposure to mercury (Hg) occurs through different pathways and forms including methylmecury (MeHg) from seafood and rice, ethylmercury (EtHg), and elemental Hg (Hg0) from dental amalgams and artisanal gold mining. Once in the brain all these forms are transformed to inorganic Hg (I-Hg), where it bioaccumulates and remains for long periods. Hg is a well-known neurotoxicant, with its most damaging effects reported during brain development, when cellular key events, such as cell differentiation take place. A considerable number of studies report an impairment of neuronal differentiation due to MeHg exposure, however the effects of I-Hg, an important form of Hg found in brain, have received less attention. In this study, we decided to examine the effects of I-Hg exposure (5, 10 and 20μM) on the differentiation of SH-SY5Y cells induced by retinoic acid (RA, 10μM). We observed extension of neuritic processes and increased expression of neuronal markers (MAP2, tubulin-βIII, and Tau) after RA stimulation, all these effects were decreased by the co-exposure to I-Hg. Interestingly, I-Hg increased the levels of reactive oxygen species (ROS) and nitric oxide (NO) accompanied with increased levels of inducible nitric oxide synthase (iNOS) and, dimethylarginine dimethylaminohydrolase 1 (DDHA1). Remarkably I-Hg decreased levels of nitric oxide synthase neuronal (nNOS). Moreover I-Hg reduced the levels of tyrosine hydroxylase (TH) and amyloid precursor protein (APP) a protein recently involved in neuronal differentiation. These data suggest that the exposure to I-Hg impairs cell differentiation, and point to new potential targets of Hg toxicity such as APP and NO signaling.
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Affiliation(s)
- Miguel Chin Chan
- Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico; Facultad de Ciencias Químico Biológicas, Universidad Autónoma de Campeche, Campeche 4039, Mexico
| | - Elizabeth Bautista
- Departmento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico; Facultad de Ciencias de la Salud, Universidad Anáhuac Norte, 52786, Huixquilucan, Mexico
| | - Isabel Alvarado-Cruz
- Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico
| | - Betzabet Quintanilla-Vega
- Departmento de Toxicología, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico
| | - José Segovia
- Departmento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Mexico City, 07360, Mexico.
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10
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Boatti L, Rapallo F, Viarengo A, Marsano F. Toxic effects of mercury on the cell nucleus of Dictyostelium discoideum. ENVIRONMENTAL TOXICOLOGY 2017; 32:417-425. [PMID: 26888062 DOI: 10.1002/tox.22245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 01/15/2016] [Accepted: 01/24/2016] [Indexed: 06/05/2023]
Abstract
Governmental agencies (www.epa.gov/mercury) and the scientific community have reported on the high toxicity due to mercury. Indeed, exposure to mercury can cause severe injury to the central nervous system and kidney in humans. Beyond its recognized toxicity, little is known regarding the molecular mechanisms involved in the actions of this heavy metal. Mercury has been also observed to form insoluble fibrous protein aggregates in the cell nucleus. We used D. discoideum to evaluate micronuclei formation and, since mercury is able to induce oxidative stress that could bring to protein aggregation, we assessed nuclear protein carbonylation by Western Blot. We observed a significant increase in micronuclei formation and 14 carbonylated proteins were identified. Moreover, we used isotope-coded protein label (ICPL) and mass spectrometry analysis of proteins obtained by lysis of purified nuclei, before of tryptic digestion to quantify nuclear proteins affected by mercury. In particular, we examined the effects of mercury that associate a classical genotoxic assay to proteomic effects into the nucleus. The data present direct evidences for mercury genotoxicity, nuclear protein carbonylation, quantitative change in core histones, and the involvement of pseudouridine synthase in mercury toxicity. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 417-425, 2017.
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Affiliation(s)
- Lara Boatti
- Department of Science and Technological Innovation (DiSIT), Università Del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, Alessandria, 11-15121, Italy
| | - Fabio Rapallo
- Department of Science and Technological Innovation (DiSIT), Università Del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, Alessandria, 11-15121, Italy
| | - Aldo Viarengo
- Department of Science and Technological Innovation (DiSIT), Università Del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, Alessandria, 11-15121, Italy
| | - Francesco Marsano
- Department of Science and Technological Innovation (DiSIT), Università Del Piemonte Orientale "Amedeo Avogadro", Viale Teresa Michel, Alessandria, 11-15121, Italy
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11
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Scharf A, Gührs KH, von Mikecz A. Anti-amyloid compounds protect from silica nanoparticle-induced neurotoxicity in the nematode C. elegans. Nanotoxicology 2015; 10:426-35. [PMID: 26444998 PMCID: PMC4819850 DOI: 10.3109/17435390.2015.1073399] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Identifying nanomaterial-bio-interactions are imperative due to the broad introduction of nanoparticle (NP) applications and their distribution. Here, we demonstrate that silica NPs effect widespread protein aggregation in the soil nematode Caenorhabditis elegans ranging from induction of amyloid in nucleoli of intestinal cells to facilitation of protein aggregation in body wall muscles and axons of neural cells. Proteomic screening revealed that exposure of adult C. elegans with silica NPs promotes segregation of proteins belonging to the gene ontology (GO) group of “protein folding, proteolysis and stress response” to an SDS-resistant aggregome network. Candidate proteins in this group include chaperones, heat shock proteins and subunits of the 26S proteasome which are all decisively involved in protein homeostasis. The pathway of protein homeostasis was validated as a major target of silica NPs by behavioral phenotyping, as inhibitors of amyloid formation rescued NP-induced defects of locomotory patterns and egg laying. The analysis of a reporter worm for serotonergic neural cells revealed that silica NP-induced protein aggregation likewise occurs in axons of HSN neurons, where presynaptic accumulation of serotonin, e.g. disturbed axonal transport reduces the capacity for neurotransmission and egg laying. The results suggest that in C. elegans silica NPs promote a cascade of events including disturbance of protein homeostasis, widespread protein aggregation and inhibition of serotonergic neurotransmission which can be interrupted by compounds preventing amyloid fibrillation.
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Affiliation(s)
- Andrea Scharf
- a IUF - Leibniz Research Institute for Environmental Medicine at the Heinrich-Heine-University Duesseldorf , Düsseldorf , Germany and
| | - Karl-Heinz Gührs
- b CF Proteomics, FLI-Leibniz-Institute for Age Research, Fritz-Lipman-Institute e.V. , Jena , Germany
| | - Anna von Mikecz
- a IUF - Leibniz Research Institute for Environmental Medicine at the Heinrich-Heine-University Duesseldorf , Düsseldorf , Germany and
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