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Bhopatkar AA, Kayed R. Flanking regions, amyloid cores, and polymorphism: the potential interplay underlying structural diversity. J Biol Chem 2023; 299:105122. [PMID: 37536631 PMCID: PMC10482755 DOI: 10.1016/j.jbc.2023.105122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/10/2023] [Accepted: 07/28/2023] [Indexed: 08/05/2023] Open
Abstract
The β-sheet-rich amyloid core is the defining feature of protein aggregates associated with neurodegenerative disorders. Recent investigations have revealed that there exist multiple examples of the same protein, with the same sequence, forming a variety of amyloid cores with distinct structural characteristics. These structural variants, termed as polymorphs, are hypothesized to influence the pathological profile and the progression of different neurodegenerative diseases, giving rise to unique phenotypic differences. Thus, identifying the origin and properties of these structural variants remain a focus of studies, as a preliminary step in the development of therapeutic strategies. Here, we review the potential role of the flanking regions of amyloid cores in inducing polymorphism. These regions, adjacent to the amyloid cores, show a preponderance for being structurally disordered, imbuing them with functional promiscuity. The dynamic nature of the flanking regions can then manifest in the form of conformational polymorphism of the aggregates. We take a closer look at the sequences flanking the amyloid cores, followed by a review of the polymorphic aggregates of the well-characterized proteins amyloid-β, α-synuclein, Tau, and TDP-43. We also consider different factors that can potentially influence aggregate structure and how these regions can be viewed as novel targets for therapeutic strategies by utilizing their unique structural properties.
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Affiliation(s)
- Anukool A Bhopatkar
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas, USA; Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, Galveston, Texas, USA; Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas, USA.
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2
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Trasviña-Arenas CH, Ayala Medina LA, Vique-Sánchez JL. γ-Secretase Inhibitors Selected by Molecular Docking, to Develop a New Drug Against Alzheimer's Disease. Rep Biochem Mol Biol 2023; 12:340-349. [PMID: 38317814 PMCID: PMC10838598 DOI: 10.61186/rbmb.12.2.340] [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: 08/09/2023] [Accepted: 09/15/2023] [Indexed: 02/07/2024]
Abstract
Background Alzheimer´s disease (AD) is one of the most common forms of dementia, is characterized by memory loss and cognitive impairment that affects more than 30 million people worldwide. The pathogenesis of Alzheimer's disease is primary driven by brain accumulation of the amyloid β peptide generated from the amyloid-β precursor protein (APP) via cleavages by β- and γ-secretase. In this study, we propose an approach by molecular docking to select compounds as γ-secretase inhibitors for decreasing the APP generation. Methods We selected potential γ-secretase inhibitors by molecular docking in the potential site between Asp257, Lue268, Asp385, Ile387, Phe388, and Leu432 amino acids in presenilin-1 (PS-1), using a chemical library of over 500,000 compounds. Results Eight compounds (AZ1 - AZ8) were selected by molecular docking to develop γ-secretase inhibitors for decreasing the APP generation. Conclusions AZ1 - AZ8 compounds could be interacting in the potential site between Asp257, Lue268, Asp385, Ile387, Phe388, and Leu432 amino acids in PS-1. These compounds could specifically interact in the binding pocket in PS-1 to prevent/decrease the APP generation, to develop a new drug against Alzheimer's disease.
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Affiliation(s)
- Carlos Humberto Trasviña-Arenas
- Research Center on Aging, Center for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV), Calzada de los Tenorios No. 235, 14330, Mexico City, Mexico.
| | | | - José Luis Vique-Sánchez
- School of Medicine Campus Mexicali, Autonomous University of Baja California, Mexicali, 21000, BC, México.
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3
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Kunze LH, Ruch F, Biechele G, Eckenweber F, Wind-Mark K, Dinkel L, Feyen P, Bartenstein P, Ziegler S, Paeger L, Tahirovic S, Herms J, Brendel M. Long-Term Pioglitazone Treatment Has No Significant Impact on Microglial Activation and Tau Pathology in P301S Mice. Int J Mol Sci 2023; 24:10106. [PMID: 37373253 DOI: 10.3390/ijms241210106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Neuroinflammation is one disease hallmark on the road to neurodegeneration in primary tauopathies. Thus, immunomodulation might be a suitable treatment strategy to delay or even prevent the occurrence of symptoms and thus relieve the burden for patients and caregivers. In recent years, the peroxisome proliferator-activated receptor γ (PPARγ) has received increasing attention as it is immediately involved in the regulation of the immune system and can be targeted by the anti-diabetic drug pioglitazone. Previous studies have shown significant immunomodulation in amyloid-β (Aβ) mouse models by pioglitazone. In this study, we performed long-term treatment over six months in P301S mice as a tauopathy model with either pioglitazone or placebo. We performed serial 18 kDa translocator protein positron-emission-tomography (TSPO-PET) imaging and terminal immunohistochemistry to assess microglial activation during treatment. Tau pathology was quantified via immunohistochemistry at the end of the study. Long-term pioglitazone treatment had no significant effect on TSPO-PET, immunohistochemistry read-outs of microglial activation, or tau pathology levels in P301S mice. Thus, we conclude that pioglitazone modifies the time course of Aβ-dependent microglial activation, but does not significantly modulate microglial activation in response to tau pathology.
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Affiliation(s)
- Lea Helena Kunze
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - François Ruch
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
| | - Gloria Biechele
- Department of Radiology, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
| | - Florian Eckenweber
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
| | - Karin Wind-Mark
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Lina Dinkel
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Paul Feyen
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Ludwig Maximilian University of Munich, 81377 Munich, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
| | - Lars Paeger
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Ludwig Maximilian University of Munich, 81377 Munich, Germany
- Center for Neuropathology and Prion Research, LMU Munich, Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of LMU Munich, Marchioninistraße 15, 81377 Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Feodor-Lynen-Str. 17, 81377 Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Ludwig Maximilian University of Munich, 81377 Munich, Germany
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4
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Orzeł U, Pasznik P, Miszta P, Lorkowski M, Niewieczerzał S, Jakowiecki J, Filipek S. GS-SMD server for steered molecular dynamics of peptide substrates in the active site of the γ-secretase complex. Nucleic Acids Res 2023:7173862. [PMID: 37207343 DOI: 10.1093/nar/gkad409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/15/2023] [Accepted: 05/04/2023] [Indexed: 05/21/2023] Open
Abstract
Despite recent advances in research, the mechanism of Alzheimer's disease is not fully understood yet. Understanding the process of cleavage and then trimming of peptide substrates, can help selectively block γ-secretase (GS) to stop overproduction of the amyloidogenic products. Our GS-SMD server (https://gs-smd.biomodellab.eu/) allows cleaving and unfolding of all currently known GS substrates (more than 170 peptide substrates). The substrate structure is obtained by threading of the substrate sequence into the known structure of GS complex. The simulations are performed in an implicit water-membrane environment so they are performed rather quickly, 2-6 h per job, depending on the mode of calculations (part of GS complex or the whole structure). It is also possible to introduce mutations to the substrate and GS and pull any part of the substrate in any direction using the steered molecular dynamics (SMD) simulations with constant velocity. The obtained trajectories are visualized and analyzed in the interactive way. One can also compare multiple simulations using the interaction frequency analysis. GS-SMD server can be useful for revealing mechanisms of substrate unfolding and role of mutations in this process.
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Affiliation(s)
- Urszula Orzeł
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Paweł Pasznik
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Przemysław Miszta
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Marcin Lorkowski
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Szymon Niewieczerzał
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Jakub Jakowiecki
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Sławomir Filipek
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
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The Binding of Different Substrate Molecules at the Docking Site and the Active Site of γ-Secretase Can Trigger Toxic Events in Sporadic and Familial Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24031835. [PMID: 36768156 PMCID: PMC9915333 DOI: 10.3390/ijms24031835] [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: 11/18/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/19/2023] Open
Abstract
Pathogenic changes in γ-secretase activity, along with its response to different drugs, can be affected by changes in the saturation of γ-secretase with its substrate. We analyze the saturation of γ-secretase with its substrate using multiscale molecular dynamics studies. We found that an increase in the saturation of γ-secretase with its substrate could result in the parallel binding of different substrate molecules at the docking site and the active site. The C-terminal domain of the substrate bound at the docking site can interact with the most dynamic presenilin sites at the cytosolic end of the active site tunnel. Such interactions can inhibit the ongoing catalytic activity and increase the production of the longer, more hydrophobic, and more toxic Aβ proteins. Similar disruptions in dynamic presenilin structures can be observed with different drugs and disease-causing mutations. Both, C99-βCTF-APP substrate and its different Aβ products, can support the toxic aggregation. The aggregation depends on the substrate N-terminal domain. Thus, the C99-βCTF-APP substrate and β-secretase path can be more toxic than the C83-αCTF-APP substrate and α-secretase path. Nicastrin can control the toxic aggregation in the closed conformation. The binding of the C99-βCTF-APP substrate to γ-secretase can be controlled by substrate channeling between the nicastrin and β-secretase. We conclude that the presented two-substrate mechanism could explain the pathogenic changes in γ-secretase activity and Aβ metabolism in different sporadic and familial cases of Alzheimer's disease. Future drug-development efforts should target different cellular mechanisms that regulate the optimal balance between γ-secretase activity and amyloid metabolism.
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6
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Chen SY, Zacharias M. An internal docking site stabilizes substrate binding to γ-secretase: Analysis by Molecular Dynamics Simulations. Biophys J 2022; 121:2330-2344. [PMID: 35598043 DOI: 10.1016/j.bpj.2022.05.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/26/2022] [Accepted: 05/17/2022] [Indexed: 11/02/2022] Open
Abstract
Amyloid precursor protein (APP) is cleaved and processed sequentially by γ-secretase yielding amyloid β-peptides (Aβ) of different lengths. Longer Aβ peptides are associated with the formation of neurotoxic plaques related to Alzheimer's disease. Based on the APP substrate-bound structure of γ-secretase we investigated the enzyme-substrate interaction using Molecular Dynamics simulations and generated model structures that represent the sequentially cleaved intermediates during the processing reaction. The simulations indicated an internal docking site providing strong enzyme-substrate packing interaction. In the enzyme-substrate complex it is located close to the region where the helical conformation of the substrate is interrupted and continues towards the active site in an extended conformation. The internal docking site consists of two non-polar pockets that are preferentially filled by large hydrophobic or aromatic substrate side chains to stabilize binding. Placement of smaller residues such as glycine can trigger a shift in the cleavage pattern during the simulations or results in destabilization of substrate binding. The reduced packing by smaller residues also influences the hydration of the active site and the formation of a catalytically active state. The simulations on processed substrate intermediates and a substrate G33I mutation offer an explanation of the experimentally observed relative increase of short Aβ fragments production for this mutation. In addition, studies on a substrate K28A mutation indicate that the internal docking site opposes the tendency of substrate dissociation due a hydrophobic mismatch at the membrane boundary caused by K28 during processing and substrate movement towards the enzyme active site. The proposed internal docking site could also be useful for the specific design of new γ-secretase modulators.
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Affiliation(s)
- Shu-Yu Chen
- Physics Department and Center of Functional Protein Assemblies, Technical University of Munich, 85748 Garching, Germany
| | - Martin Zacharias
- Physics Department and Center of Functional Protein Assemblies, Technical University of Munich, 85748 Garching, Germany.
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7
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Braun GA, Dear AJ, Sanagavarapu K, Zetterberg H, Linse S. Amyloid-β peptide 37, 38 and 40 individually and cooperatively inhibit amyloid-β 42 aggregation. Chem Sci 2022; 13:2423-2439. [PMID: 35310497 PMCID: PMC8864715 DOI: 10.1039/d1sc02990h] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 01/22/2022] [Indexed: 12/22/2022] Open
Abstract
The pathology of Alzheimer's disease is connected to the aggregation of β-amyloid (Aβ) peptide, which in vivo exists as a number of length-variants. Truncations and extensions are found at both the N- and C-termini, relative to the most commonly studied 40- and 42-residue alloforms. Here, we investigate the aggregation of two physiologically abundant alloforms, Aβ37 and Aβ38, as pure peptides and in mixtures with Aβ40 and Aβ42. A variety of molar ratios were applied in quaternary mixtures to investigate whether a certain ratio is maximally inhibiting of the more toxic alloform Aβ42. Through kinetic analysis, we show that both Aβ37 and Aβ38 self-assemble through an autocatalytic secondary nucleation reaction to form fibrillar β-sheet-rich aggregates, albeit on a longer timescale than Aβ40 or Aβ42. Additionally, we show that the shorter alloforms co-aggregate with Aβ40, affecting both the kinetics of aggregation and the resulting fibrillar ultrastructure. In contrast, neither Aβ37 nor Aβ38 forms co-aggregates with Aβ42; however, both short alloforms reduce the rate of Aβ42 aggregation in a concentration-dependent manner. Finally, we show that the aggregation of Aβ42 is more significantly impeded by a combination of Aβ37, Aβ38, and Aβ40 than by any of these alloforms independently. These results demonstrate that the aggregation of any given Aβ alloform is significantly perturbed by the presence of other alloforms, particularly in heterogeneous mixtures, such as is found in the extracellular fluid of the brain.
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Affiliation(s)
- Gabriel A Braun
- Biochemistry and Structural Biology, Lund University Lund Sweden
| | - Alexander J Dear
- Biochemistry and Structural Biology, Lund University Lund Sweden .,Department of Cell Biology, Harvard Medical School Boston MA USA.,Paulson School of Engineering and Applied Science, Harvard University Cambridge MA USA.,Department of Chemistry, University of Cambridge Cambridge UK
| | | | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg Mölndal Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital Mölndal Sweden.,Department of Neurodegenerative Disease, UCL Institute of Neurology Queen Square London UK.,UK Dementia Research Institute at UCL London UK
| | - Sara Linse
- Biochemistry and Structural Biology, Lund University Lund Sweden
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8
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Congdon EE, Jiang Y, Sigurdsson EM. Targeting tau only extracellularly is likely to be less efficacious than targeting it both intra- and extracellularly. Semin Cell Dev Biol 2021; 126:125-137. [PMID: 34896021 DOI: 10.1016/j.semcdb.2021.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 12/11/2022]
Abstract
Aggregation of the tau protein is thought to be responsible for the neurodegeneration and subsequent functional impairments in diseases that are collectively named tauopathies. Alzheimer's disease is the most common tauopathy, but the group consists of over 20 different diseases, many of which have tau pathology as their primary feature. The development of tau therapies has mainly focused on preventing the formation of and/or clearing these aggregates. Of these, immunotherapies that aim to either elicit endogenous tau antibodies or deliver exogenous ones are the most common approach in clinical trials. While their mechanism of action can involve several pathways, both extra- and intracellular, pharmaceutical companies have primarily focused on antibody-mediated clearance of extracellular tau. As we have pointed out over the years, this is rather surprising because it is well known that most of pathological tau protein is found intracellularly. It has been repeatedly shown by several groups over the past decades that antibodies can enter neurons and that their cellular uptake can be enhanced by various means, particularly by altering their charge. Here, we will briefly describe the potential extra- and intracellular mechanisms involved in antibody-mediated clearance of tau pathology, discuss these in the context of recent failures of some of the tau antibody trials, and finally provide a brief overview of how the intracellular efficacy of tau antibodies can potentially be further improved by certain modifications that aim to enhance tau clearance via specific intracellular degradation pathways.
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Affiliation(s)
- Erin E Congdon
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, United States.
| | - Yixiang Jiang
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, United States
| | - Einar M Sigurdsson
- Department of Neuroscience and Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY 10016, United States; Department of Psychiatry, New York University Grossman School of Medicine, New York, NY 10016, United States.
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9
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Ijomone OM, Iroegbu JD, Aschner M, Bornhorst J. Impact of environmental toxicants on p38- and ERK-MAPK signaling pathways in the central nervous system. Neurotoxicology 2021; 86:166-171. [PMID: 34389354 PMCID: PMC8440482 DOI: 10.1016/j.neuro.2021.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 12/16/2022]
Abstract
There are several candidate signalling pathways that mediate the response of the central nervous system (CNS) cells to environmental toxins. However, much is still to be learned on how these pathways modulate neurotoxicity. The mitogen-activated protein kinases (MAPKs) signalling pathways, which include the extracellular signal-regulated protein kinase (ERK) and the p38-MAPK, are potentially key pathways to regulate CNS responses to environmental toxins. The pathways play leading roles in the transmission of extracellular signals into the cell nucleus, leading to cell differentiation, cell growth, and apoptosis, to name a few. Moreover, exposure to environmental toxins induces p38- and ERK-MAPK activation, which leads to oxidative stress, inflammation, and apoptosis in the CNS. Here, we provide a concise review of the recent evidence demonstrating the role of p38- and ERK-MAPK signaling pathways and their downstream targets in the CNS following exposure to environmental toxicants such as metals, organophosphorus and persistent organic pollutants.
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Affiliation(s)
- Omamuyovwi M Ijomone
- Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany; The Neuro- Lab, Department of Human Anatomy, School of Health and Health Technology, Federal University of Technology Akure, Akure, Nigeria.
| | - Joy D Iroegbu
- The Neuro- Lab, Department of Human Anatomy, School of Health and Health Technology, Federal University of Technology Akure, Akure, Nigeria
| | - Michael Aschner
- Departments of Molecular Pharmacology and Neurosciences, Albert Einstein College of Medicine, NY, USA
| | - Julia Bornhorst
- Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany
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Loosening ER-Mitochondria Coupling by the Expression of the Presenilin 2 Loop Domain. Cells 2021; 10:cells10081968. [PMID: 34440738 PMCID: PMC8394530 DOI: 10.3390/cells10081968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 11/17/2022] Open
Abstract
Presenilin 2 (PS2), one of the three proteins in which mutations are linked to familial Alzheimer's disease (FAD), exerts different functions within the cell independently of being part of the γ-secretase complex, thus unrelated to toxic amyloid peptide formation. In particular, its enrichment in endoplasmic reticulum (ER) membrane domains close to mitochondria (i.e., mitochondria-associated membranes, MAM) enables PS2 to modulate multiple processes taking place on these signaling hubs, such as Ca2+ handling and lipid synthesis. Importantly, upregulated MAM function appears to be critical in AD pathogenesis. We previously showed that FAD-PS2 mutants reinforce ER-mitochondria tethering, by interfering with the activity of mitofusin 2, favoring their Ca2+ crosstalk. Here, we deepened the molecular mechanism underlying PS2 activity on ER-mitochondria tethering, identifying its protein loop as an essential domain to mediate the reinforced ER-mitochondria connection in FAD-PS2 models. Moreover, we introduced a novel tool, the PS2 loop domain targeted to the outer mitochondrial membrane, Mit-PS2-LOOP, that is able to counteract the activity of FAD-PS2 on organelle tethering, which possibly helps in recovering the FAD-PS2-associated cellular alterations linked to an increased organelle coupling.
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11
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Wiatrak B, Piasny J, Kuźniarski A, Gąsiorowski K. Interactions of Amyloid-β with Membrane Proteins. Int J Mol Sci 2021; 22:6075. [PMID: 34199915 PMCID: PMC8200087 DOI: 10.3390/ijms22116075] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/31/2021] [Accepted: 06/03/2021] [Indexed: 12/11/2022] Open
Abstract
In developing and developed countries, an increasing elderly population is observed. This affects the growing percentage of people struggling with neurodegenerative diseases, including Alzheimer's disease. Nevertheless, the pathomechanism of this disease is still unknown. This contributes to problems with early diagnosis of the disease as well as with treatment. One of the most popular hypotheses of Alzheimer's disease is related to the pathological deposition of amyloid-β (Aβ) in the brain of ill people. In this paper, we discuss issues related to Aβ and its relationship in the development of Alzheimer's disease. The structure of Aβ and its interaction with the cell membrane are discussed. Not only do the extracellular plaques affect nerve cells, but other forms of this peptide as well.
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Affiliation(s)
- Benita Wiatrak
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wroclaw, Poland
- Department of Basic Medical Sciences, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland;
| | - Janusz Piasny
- Department of Pharmacology, Wroclaw Medical University, Mikulicza-Radeckiego 2, 50-345 Wroclaw, Poland
| | - Amadeusz Kuźniarski
- Department of Prosthetic Dentistry, Wroclaw Medical University, Krakowska 26, 50-425 Wroclaw, Poland;
| | - Kazimierz Gąsiorowski
- Department of Basic Medical Sciences, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland;
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