1
|
Nutini A. Amyloid oligomers and their membrane toxicity - A perspective study. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2024; 187:9-20. [PMID: 38211711 DOI: 10.1016/j.pbiomolbio.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/21/2023] [Accepted: 01/07/2024] [Indexed: 01/13/2024]
Abstract
Amyloidosis is a condition involving a disparate group of pathologies characterized by the extracellular deposition of insoluble fibrils composed of broken-down proteins. These proteins can accumulate locally, causing peculiar symptoms, or in a widespread way, involving many organs and. causing severe systemic failure. The damage that is created is related not only to the accumulation of. amyloid fibrils but above all to the precursor oligomers of the fibrils that manage to enter the cell in a very particular way. This article analyzes the current state of research related to the entry of these oligomers into the cell membrane and the theories related to their toxicity. The paper proposed here not only aims to review the contents in the literature but also proposes a new vision of amyloid toxicity. that could occur in a multiphase process catalyzed by the cell membrane itself. In this process, the denaturation of the lipid bilayer is followed by the stabilization of a pore through energetically favorable self-assembly processes which are achieved through particular oligomeric structures.
Collapse
Affiliation(s)
- Alessandro Nutini
- Biology and Biomechanics Dept - Centro Studi Attività Motorie, Italy.
| |
Collapse
|
2
|
Subbamanda YD, Bhargava A. Intercommunication between Voltage-Gated Calcium Channels and Estrogen Receptor/Estrogen Signaling: Insights into Physiological and Pathological Conditions. Cells 2022; 11:cells11233850. [PMID: 36497108 PMCID: PMC9739980 DOI: 10.3390/cells11233850] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Voltage-gated calcium channels (VGCCs) and estrogen receptors are important cellular proteins that have been shown to interact with each other across varied cells and tissues. Estrogen hormone, the ligand for estrogen receptors, can also exert its effects independent of estrogen receptors that collectively constitute non-genomic mechanisms. Here, we provide insights into the VGCC regulation by estrogen and the possible mechanisms involved therein across several cell types. Notably, most of the interaction is described in neuronal and cardiovascular tissues given the importance of VGCCs in these electrically excitable tissues. We describe the modulation of various VGCCs by estrogen known so far in physiological conditions and pathological conditions. We observed that in most in vitro studies higher concentrations of estrogen were used while a handful of in vivo studies used meager concentrations resulting in inhibition or upregulation of VGCCs, respectively. There is a need for more relevant physiological assays to study the regulation of VGCCs by estrogen. Additionally, other interacting receptors and partners need to be identified that may be involved in exerting estrogen receptor-independent effects of estrogen.
Collapse
|
3
|
Kaisis E, Thei LJ, Stephens GJ, Dallas ML. Protofibrillar Amyloid Beta Modulation of Recombinant hCaV2.2 (N-Type) Voltage-Gated Channels. Pharmaceuticals (Basel) 2022; 15:ph15121459. [PMID: 36558910 PMCID: PMC9783047 DOI: 10.3390/ph15121459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Cav2.2 channels are key regulators of presynaptic Ca2+ influx and their dysfunction and/or aberrant regulation has been implicated in many disease states; however, the nature of their involvement in Alzheimer's disease (AD) is less clear. In this short communication, we show that recombinant hCav2.2/b1b/a2d1 channels are modulated by human synthetic AD-related protofibrillar amyloid beta Ab1-42 peptides. Structural studies revealed a time-dependent increase in protofibril length, with the majority of protofibrils less than 100 nm at 24 h, while at 48 h, the majority were longer than 100 nm. Cav2.2 modulation by Ab1-42 was different between a 'low' (100 nM) and 'high' (1 µM) concentration in terms of distinct effects on individual biophysical parameters. A concentration of 100 nM Ab1-42 caused no significant changes in the measured biophysical properties of Cav2.2 currents. In contrast, 1 µM Ab1-42 caused an inhibitory decrease in the current density (pA/pF) and maximum conductance (Gmax), and a depolarizing shift in the slope factor (k). These data highlight a differential modulation of Cav2.2 channels by the Ab1-42 peptide. Discrete changes in the presynaptic Ca2+ flux have been reported to occur at an early stage of AD; therefore, this study reveals a potential mechanistic link between amyloid accumulation and Cav2.2 channel modulation.
Collapse
|
4
|
Cheng K, Huang C, Hsieh T, Chiang H. Disrupted cellular calcium homeostasis is responsible for Aβ‐induced learning and memory damage and lifespan shortening in a model of Aβ transgenic fly. IUBMB Life 2022; 74:754-762. [DOI: 10.1002/iub.2621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 04/11/2022] [Indexed: 12/27/2022]
Affiliation(s)
- Kuan‐Chung Cheng
- Department of Pharmacology, College of Medicine National Cheng‐Kung University Tainan Taiwan
- Institute of Basic Medical Sciences, College of Medicine National Cheng‐Kung University Tainan Taiwan
| | - Chih‐Yuan Huang
- Division of Nephrology, Department of Internal Medicine Ditmanson Medical Foundation Chia‐Yi Christian Hospital Chiayi Taiwan
- Department of Sport Management, College of Recreation and Health Management Chia Nan University of Pharmacy and Science Tainan Taiwan
| | - Tsung‐Chi Hsieh
- Department of Pharmacology, College of Medicine National Cheng‐Kung University Tainan Taiwan
- Institute of Basic Medical Sciences, College of Medicine National Cheng‐Kung University Tainan Taiwan
- Brain Research Center National Tsing Hua University Hsinchu City Taiwan
| | - Hsueh‐Cheng Chiang
- Department of Pharmacology, College of Medicine National Cheng‐Kung University Tainan Taiwan
- Institute of Basic Medical Sciences, College of Medicine National Cheng‐Kung University Tainan Taiwan
| |
Collapse
|
5
|
Olajide OJ, Gbadamosi IT, Yawson EO, Arogundade T, Lewu FS, Ogunrinola KY, Adigun OO, Bamisi O, Lambe E, Arietarhire LO, Oluyomi OO, Idowu OK, Kareem R, Asogwa NT, Adeniyi PA. Hippocampal Degeneration and Behavioral Impairment During Alzheimer-Like Pathogenesis Involves Glutamate Excitotoxicity. J Mol Neurosci 2021; 71:1205-1220. [PMID: 33420680 DOI: 10.1007/s12031-020-01747-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/26/2020] [Indexed: 12/20/2022]
Abstract
The hallmarks of Alzheimer's disease (AD) pathology include senile plaques accumulation and neurofibrillary tangles, which is thought to underlie synaptic failure. Recent evidence however supports that synaptic failure in AD may instead be instigated by enhanced N-methyl-D-aspartate (NMDA) activity, via a reciprocal relationship between soluble amyloid-β (Aβ) accumulation and increased glutamate agonist. While previous studies have shown Aβ-mediated alterations to the glutamatergic system during AD, the underlying etiology of excitotoxic glutamate-induced changes has not been explored. Here, we investigated the acute effects of stereotaxic dentate gyrus (DG) glutamate injection on behavior and molecular expression of specific proteins and neurochemicals modulating hippocampal functions. Dependence of glutamate-mediated effects on NMDA receptor (NMDAR) hyperactivation was tested using NMDARs antagonist memantine. DG of Wistar rats (12-weeks-old) were bilaterally microinjected with glutamate (500 mM) with or without daily intraperitoneal (i.p.) memantine injection (20 mg/kg) for 14 days, while controls received either intrahippocampal/i.p. PBS or i.p. memantine. Behavioral characterization in open field and Y-maze revealed that glutamate evoked anxiogenic responses and perturbed spatial memory were inhibited by memantine. In glutamate-treated rats, increased NO expression was accompanied by marked reduction in profiles of glutathione-s-transferase and glutathione peroxidase. Similarly, glutamate-mediated increase in acetylcholinesterase expression corroborated downregulation of synaptophysin and PSD-95, coupled with initiation of reactive astrogliosis (GFAP). While neurofilament immunolocalization/immunoexpression was unperturbed, we found glutamate-mediated reduction in neurogenic markers Ki67 and PCNA immunoexpression, with a decrease in NR2B protein expression, whereas mGluR1 remains unchanged. In addition, increased expression of apoptotic regulatory proteins p53 and Bax was seen in glutamate infused rats, corroborating chromatolytic degeneration of granule neurons in the DG. Interestingly, memantine abrogated most of the degenerative changes associated with glutamate excitotoxicity in this study. Taken together, our findings causally link acute glutamate dyshomeostasis in the DG with development of AD-related behavioral impairment and molecular neurodegeneration.
Collapse
Affiliation(s)
- Olayemi Joseph Olajide
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria. .,Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, Canada.
| | - Ismail Tayo Gbadamosi
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,Central Research Laboratories Ltd, 132b University Road, Ilorin, Nigeria
| | - Emmanuel Olusola Yawson
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,Department of Anatomy, Faculty of Basic Medical Sciences, Redeemer's University, Ede, Nigeria
| | - Tolulope Arogundade
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,Department of Anatomy, Faculty of Basic Medical Sciences, Adeleke University, Ede, Nigeria
| | - Folashade Susan Lewu
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Kehinde Yomi Ogunrinola
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,Department of Anatomy, School of Post-Basic Nursing, University of Ilorin Teaching Hospital, Ilorin, Nigeria
| | - Oluwaseun Olaniyi Adigun
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Olawande Bamisi
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.,Department of Anatomy, Faculty of Basic Medical Sciences, Ekiti State University, Ado Ekiti, Nigeria
| | - Ezra Lambe
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Leviticus Ogbenevurinrin Arietarhire
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Olushola Oladapo Oluyomi
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Olumayowa Kolawole Idowu
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Rukayat Kareem
- Department of Anatomy, Division of Neurobiology, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria
| | - Nnaemeka Tobechukwu Asogwa
- Central Research Laboratories Ltd, 132b University Road, Ilorin, Nigeria.,Department of Biochemistry, Faculty of Life Sciences, University of Ilorin, Ilorin, Nigeria
| | - Philip Adeyemi Adeniyi
- Department of Comparative Biomedical Sciences, Louisiana State University, Baton Rouge, LA, USA
| |
Collapse
|
6
|
Gao Y, Guo C, Watzlawik JO, Randolph PS, Lee EJ, Huang D, Stagg SM, Zhou HX, Rosenberry TL, Paravastu AK. Out-of-Register Parallel β-Sheets and Antiparallel β-Sheets Coexist in 150-kDa Oligomers Formed by Amyloid-β(1-42). J Mol Biol 2020; 432:4388-4407. [PMID: 32470558 DOI: 10.1016/j.jmb.2020.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 12/15/2022]
Abstract
We present solid-state NMR measurements of β-strand secondary structure and inter-strand organization within a 150-kDa oligomeric aggregate of the 42-residue variant of the Alzheimer's amyloid-β peptide (Aβ(1-42)). We build upon our previous report of a β-strand spanned by residues 30-42, which arranges into an antiparallel β-sheet. New results presented here indicate that there is a second β-strand formed by residues 11-24. Contrary to expectations, NMR data indicate that this second β-strand is organized into a parallel β-sheet despite the co-existence of an antiparallel β-sheet in the same structure. In addition, the in-register parallel β-sheet commonly observed for amyloid fibril structure does not apply to residues 11-24 in the 150-kDa oligomer. Rather, we present evidence for an inter-strand registry shift of three residues that likely alternate in direction between adjacent molecules along the β-sheet. We corroborated this unexpected scheme for β-strand organization using multiple two-dimensional NMR and 13C-13C dipolar recoupling experiments. Our findings indicate a previously unknown assembly pathway and inspire a suggestion as to why this aggregate does not grow to larger sizes.
Collapse
Affiliation(s)
- Yuan Gao
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332, USA
| | - Cong Guo
- Department of Physics and International Centre for Quantum and Molecular Structures, Shanghai University, 99 Shangda Road, Shanghai, China
| | - Jens O Watzlawik
- Departments of Neuroscience and Pharmacology, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Peter S Randolph
- Institute of Molecular Biophysics, Florida State University, Tallahasse, FL 32306, USA
| | - Elizabeth J Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332, USA
| | - Danting Huang
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332, USA
| | - Scott M Stagg
- Institute of Molecular Biophysics, Florida State University, Tallahasse, FL 32306, USA; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Huan-Xiang Zhou
- Department of Chemistry and Physics, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Terrone L Rosenberry
- Departments of Neuroscience and Pharmacology, Mayo Clinic College of Medicine, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Anant K Paravastu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332, USA.
| |
Collapse
|
7
|
Yeung JHY, Palpagama TH, Tate WP, Peppercorn K, Waldvogel HJ, Faull RLM, Kwakowsky A. The Acute Effects of Amyloid-Beta 1-42 on Glutamatergic Receptor and Transporter Expression in the Mouse Hippocampus. Front Neurosci 2020; 13:1427. [PMID: 32009891 PMCID: PMC6978747 DOI: 10.3389/fnins.2019.01427] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/17/2019] [Indexed: 01/24/2023] Open
Abstract
Alzheimer’s disease (AD) is the leading type of dementia worldwide. Despite an increasing burden of disease due to a rapidly aging population, there is still a lack of complete understanding of the precise pathological mechanisms which drive its progression. Glutamate is the main excitatory neurotransmitter in the brain and plays an essential role in the normal function and excitability of neuronal networks. While previous studies have shown alterations in the function of the glutamatergic system in AD, the underlying etiology of beta amyloid (Aβ1–42) induced changes has not been explored. Here we have investigated the acute effects of stereotaxic hippocampal Aβ1–42 injection on specific glutamatergic receptors and transporters in the mouse hippocampus, using immunohistochemistry and confocal microscopy 3 days after Aβ1–42 injection in aged male C57BL/6 mice, before the onset of neuronal cell death. We show that acute injection of Aβ1–42 is sufficient to induce cognitive deficits 3 days post-injection. We also report no significant changes in glutamate receptor subunits GluA1, GluA2, VGluT1, and VGluT2 in response to acute injection of Aβ1–42 when compared with the ACSF-vehicle injected mice. However, we observed increased expression in the DG hilus and ventral stratum (str.) granulosum, CA3 str. radiatum and str. oriens, and CA1 str. radiatum of the GluN1 subunit, and increased expression within the CA3 str. radiatum and decreased expression within the DG str. granulosum of the GluN2A subunit in Aβ1–42 injected mice compared to NC, and a similar trend observed when compared to ACSF-injected mice. We also observed alterations in expression patterns of glutamatergic receptor subunits and transporters within specific layers of hippocampal subregions in response to a microinjection stimulus. These findings indicate that the pathological alterations in the glutamatergic system observed in AD are likely to be partially a result of both acute and chronic exposure to Aβ1–42 and implies a much more complex circuit mechanism associated with glutamatergic dysfunction than simply glutamate-mediated excitotoxic neuronal death.
Collapse
Affiliation(s)
- Jason H Y Yeung
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Thulani H Palpagama
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Warren P Tate
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Katie Peppercorn
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Henry J Waldvogel
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Andrea Kwakowsky
- Centre for Brain Research, Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
8
|
Siddiqi MK, Malik S, Majid N, Alam P, Khan RH. Cytotoxic species in amyloid-associated diseases: Oligomers or mature fibrils. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 118:333-369. [PMID: 31928731 DOI: 10.1016/bs.apcsb.2019.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Amyloid diseases especially, Alzheimer's disease (AD), is characterized by an imbalance between the production and clearance of amyloid-β (Aβ) species. Amyloidogenic proteins or peptides can transform structurally from monomers into β-stranded fibrils via multiple oligomeric states. Among various amyloid species, structured oligomers are proposed to be more toxic than fibrils; however, the identification of amyloid oligomers has been challenging due to their heterogeneous and metastable nature. Multiple techniques have recently helped in better understanding of oligomer's assembly details and structural properties. Moreover, some progress on elucidating the mechanisms of oligomer-triggered toxicity has been made. Based on the collection of current findings, there is growing consensus that control of toxic amyloid oligomers could be a valid approach to regulate amyloid-associated toxicity, which could advance development of new diagnostics and therapeutics for amyloid-related diseases. In this review, we have described the recent scenario of amyloid diseases with a great deal of information about the recent understanding of oligomers' assembly, structural properties, and toxicity. Also comprehensive details have been provided to differentiate the degree of toxicity associated with prefibrillar aggregates.
Collapse
Affiliation(s)
| | - Sadia Malik
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Nabeela Majid
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Parvez Alam
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| |
Collapse
|
9
|
Amyloid β oligomers suppress excitatory transmitter release via presynaptic depletion of phosphatidylinositol-4,5-bisphosphate. Nat Commun 2019; 10:1193. [PMID: 30867420 PMCID: PMC6416269 DOI: 10.1038/s41467-019-09114-z] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 02/21/2019] [Indexed: 12/21/2022] Open
Abstract
Amyloid β (Aβ) oligomer-induced aberrant neurotransmitter release is proposed to be a crucial early event leading to synapse dysfunction in Alzheimer's disease (AD). In the present study, we report that the release probability (Pr) at the synapse between the Schaffer collateral (SC) and CA1 pyramidal neurons is significantly reduced at an early stage in mouse models of AD with elevated Aβ production. High nanomolar synthetic oligomeric Aβ42 also suppresses Pr at the SC-CA1 synapse in wild-type mice. This Aβ-induced suppression of Pr is mainly due to an mGluR5-mediated depletion of phosphatidylinositol-4,5-bisphosphate (PIP2) in axons. Selectively inhibiting Aβ-induced PIP2 hydrolysis in the CA3 region of the hippocampus strongly prevents oligomeric Aβ-induced suppression of Pr at the SC-CA1 synapse and rescues synaptic and spatial learning and memory deficits in APP/PS1 mice. These results first reveal the presynaptic mGluR5-PIP2 pathway whereby oligomeric Aβ induces early synaptic deficits in AD.
Collapse
|
10
|
Abstract
Amyloid diseases are of major concern all over the world due to a number of factors including: (i) aging population, (ii) increasing life span and (iii) lack of effective pharmacotherapy options. The past decade has seen intense research in discovering disease-modifying multi-targeting small molecules as therapeutic options. In recent years, targeting the amyloid cascade has emerged as an attractive strategy to discover novel neurotherapeutics. Formation of amyloid species, with different degrees of solubility and neurotoxicity is associated with the gradual decline in cognition leading to dementia/cell dysfunction. Here, in this chapter, we have described the recent scenario of amyloid diseases with a great deal of information about the structural features of oligomers, protofibrils and fibrils. Also, comprehensive details have been provided to differentiate the degree of toxicity associated with prefibrillar aggregates. Moreover, a review of the technologies that aid characterisation of oligomer, protofibrils and fibrils as well as various inhibition strategies to overcome protein fibrillation are also discussed.
Collapse
Affiliation(s)
| | - Nabeela Majid
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, U.P., India
| | - Sadia Malik
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, U.P., India
| | - Parvez Alam
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, U.P., India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, U.P., India.
| |
Collapse
|
11
|
Ovsepian SV, O'Leary VB, Zaborszky L, Ntziachristos V, Dolly JO. Synaptic vesicle cycle and amyloid β: Biting the hand that feeds. Alzheimers Dement 2018; 14:502-513. [PMID: 29494806 DOI: 10.1016/j.jalz.2018.01.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 01/11/2018] [Accepted: 01/15/2018] [Indexed: 12/29/2022]
Abstract
The synaptic vesicle cycle (SVC) holds center stage in the biology of presynaptic terminals. Through recurrent exocytosis and endocytosis, it facilitates a sequence of events enabling chemical neurotransmission between functionally related neurons. As a fundamental process that links the interior of nerve cells with their environment, the SVC is also critical for signaling and provides an entry route for a range of pathogens and toxins, enabling detrimental effects. In Alzheimer's disease, the SVC is both the prime site of amyloid β production and toxicity. In this study, we discuss the emerging evidence for physiological and pathological effects of Aβ on various stages of the SVC, from postfusion membrane recovery to trafficking, docking, and priming of vesicles for fusion and transmitter release. Understanding of the mechanisms of Aβ interaction with the SVC within the unifying calcium hypothesis of aging and Alzheimer's disease should further elucidate the fundamental biology of the presynaptic terminal and reveal novel therapeutic targets for Alzheimer's disease and other age-related dementias.
Collapse
Affiliation(s)
- Saak V Ovsepian
- Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Neuherberg, Germany; Munich School of Bioengineering, Technical University Munich, Munich, Germany; International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland.
| | - Valerie B O'Leary
- Institute of Radiation Biology, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Laszlo Zaborszky
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, German Research Center for Environmental Health, Neuherberg, Germany; Munich School of Bioengineering, Technical University Munich, Munich, Germany
| | - J Oliver Dolly
- International Centre for Neurotherapeutics, Dublin City University, Dublin, Ireland
| |
Collapse
|
12
|
SUMOylation and calcium signalling: potential roles in the brain and beyond. Neuronal Signal 2017; 1:NS20160010. [PMID: 32714579 PMCID: PMC7373246 DOI: 10.1042/ns20160010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 12/23/2022] Open
Abstract
Small ubiquitin-like modifier (SUMO) conjugation (or SUMOylation) is a post-translational protein modification implicated in alterations to protein expression, localization and function. Despite a number of nuclear roles for SUMO being well characterized, this process has only started to be explored in relation to membrane proteins, such as ion channels. Calcium ion (Ca2+) signalling is crucial for the normal functioning of cells and is also involved in the pathophysiological mechanisms underlying relevant neurological and cardiovascular diseases. Intracellular Ca2+ levels are tightly regulated; at rest, most Ca2+ is retained in organelles, such as the sarcoplasmic reticulum, or in the extracellular space, whereas depolarization triggers a series of events leading to Ca2+ entry, followed by extrusion and reuptake. The mechanisms that maintain Ca2+ homoeostasis are candidates for modulation at the post-translational level. Here, we review the effects of protein SUMOylation, including Ca2+ channels, their proteome and other proteins associated with Ca2+ signalling, on vital cellular functions, such as neurotransmission within the central nervous system (CNS) and in additional systems, most prominently here, in the cardiac system.
Collapse
|
13
|
Tomasini MC, Borelli AC, Beggiato S, Ferraro L, Cassano T, Tanganelli S, Antonelli T. Differential Effects of Palmitoylethanolamide against Amyloid-β Induced Toxicity in Cortical Neuronal and Astrocytic Primary Cultures from Wild-Type and 3xTg-AD Mice. J Alzheimers Dis 2016; 46:407-21. [PMID: 25765918 DOI: 10.3233/jad-143039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Considering the heterogeneity of pathological changes occurring in Alzheimer's disease (AD), a therapeutic approach aimed both to neuroprotection and to neuroinflammation reduction may prove effective. Palmitoylethanolamide (PEA) has attracted attention for its anti-inflammatory/neuroprotective properties observed in AD animal models. OBJECTIVE AND METHODS We evaluated the protective role of PEA against amyloid-β₄₂ (Aβ₄₂) toxicity on cell viability and glutamatergic transmission in primary cultures of cerebral cortex neurons and astrocytes from the triple-transgenic murine model of AD (3xTg-AD) and their wild-type littermates (non-Tg) mice. RESULTS Aβ₄₂ (0.5 μM; 24 h) affects the cell viability in cultured cortical neurons and astrocytes from non-Tg mice, but not in those from 3xTg-AD mice. These effects were counteracted by the pretreatment with PEA (0.1 μM). Basal glutamate levels in cultured neurons and astrocytes from 3xTg-AD mice were lower than those observed in cultured cells from non-Tg mice. Aβ₄₂-exposure reduced and increased glutamate levels in non-Tg mouse cortical neurons and astrocytes, respectively. These effects were counteracted by the pretreatment with PEA. By itself, PEA did not affect cell viability and glutamate levels in cultured cortical neurons and astrocytes from non-Tg or 3xTg-AD mice. CONCLUSION The exposure to Aβ₄₂ induced toxic effects on cultured cortical neurons and astrocytes from non-Tg mice, but not in those from 3xTg-AD mice. Furthermore, PEA exerts differential effects against Aβ₄₂-induced toxicity in primary cultures of cortical neurons and astrocytes from non-Tg and 3xTg-AD mice. In particular, PEA displays protective properties in non-Tg but not in 3xTg-AD mouse neuronal cultured cells overexpressing Aβ.
Collapse
Affiliation(s)
- Maria Cristina Tomasini
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy.,IRET Foundation, Ozzano Emilia, Bologna, Italy
| | | | - Sarah Beggiato
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy.,IRET Foundation, Ozzano Emilia, Bologna, Italy
| | - Luca Ferraro
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy.,IRET Foundation, Ozzano Emilia, Bologna, Italy.,LTTA Centre, University of Ferrara, Italy
| | - Tommaso Cassano
- Department of Clinical and Experimental Medicine, University of Foggia, Italy
| | - Sergio Tanganelli
- IRET Foundation, Ozzano Emilia, Bologna, Italy.,Department of Medical Sciences, University of Ferrara, Italy.,LTTA Centre, University of Ferrara, Italy
| | - Tiziana Antonelli
- IRET Foundation, Ozzano Emilia, Bologna, Italy.,Department of Medical Sciences, University of Ferrara, Italy.,LTTA Centre, University of Ferrara, Italy
| |
Collapse
|
14
|
Yan R, Fan Q, Zhou J, Vassar R. Inhibiting BACE1 to reverse synaptic dysfunctions in Alzheimer's disease. Neurosci Biobehav Rev 2016; 65:326-40. [PMID: 27044452 PMCID: PMC4856578 DOI: 10.1016/j.neubiorev.2016.03.025] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 03/25/2016] [Accepted: 03/29/2016] [Indexed: 12/21/2022]
Abstract
Over the past two decades, many studies have identified significant contributions of toxic β-amyloid peptides (Aβ) to the etiology of Alzheimer's disease (AD), which is the most common age-dependent neurodegenerative disease. AD is also recognized as a disease of synaptic failure. Aβ, generated by sequential proteolytic cleavages of amyloid precursor protein (APP) by BACE1 and γ-secretase, is one of major culprits that cause this failure. In this review, we summarize current findings on how BACE1-cleaved APP products impact learning and memory through proteins localized on glutamatergic, GABAergic, and dopaminergic synapses. Considering the broad effects of Aβ on all three types of synapses, BACE1 inhibition emerges as a practical approach for ameliorating Aβ-mediated synaptic dysfunctions. Since BACE1 inhibitory drugs are currently in clinical trials, this review also discusses potential complications arising from BACE1 inhibition. We emphasize that the benefits of BACE1 inhibitory drugs will outweigh the concerns.
Collapse
Affiliation(s)
- Riqiang Yan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| | - Qingyuan Fan
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - John Zhou
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Robert Vassar
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| |
Collapse
|
15
|
Neuronal Network Oscillations in Neurodegenerative Diseases. Neuromolecular Med 2015; 17:270-84. [PMID: 25920466 DOI: 10.1007/s12017-015-8355-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 04/16/2015] [Indexed: 10/23/2022]
Abstract
Cognitive and behavioral acts go along with highly coordinated spatiotemporal activity patterns in neuronal networks. Most of these patterns are synchronized by coherent membrane potential oscillations within and between local networks. By entraining multiple neurons into a common time regime, such network oscillations form a critical interface between cellular activity and large-scale systemic functions. Synaptic integrity is altered in neurodegenerative diseases, and it is likely that this goes along with characteristic changes of coordinated network activity. This notion is supported by EEG recordings from human patients and from different animal models of such disorders. However, our knowledge about the pathophysiology of network oscillations in neurodegenerative diseases is surprisingly incomplete, and increased research efforts are urgently needed. One complicating factor is the pronounced diversity of network oscillations between different brain regions and functional states. Pathological changes must, therefore, be analyzed separately in each condition and affected area. However, cumulative evidence from different diseases may result, in the future, in more unifying "oscillopathy" concepts of neurodegenerative diseases. In this review, we report present evidence for pathological changes of network oscillations in Alzheimer's disease (AD), one of the most prominent and challenging neurodegenerative disorders. The heterogeneous findings from AD are contrasted to Parkinson's disease, where motor-related changes in specific frequency bands do already fulfill criteria of a valid biomarker.
Collapse
|
16
|
Posttraumatic stress disorder-like induction elevates β-amyloid levels, which directly activates corticotropin-releasing factor neurons to exacerbate stress responses. J Neurosci 2015; 35:2612-23. [PMID: 25673853 DOI: 10.1523/jneurosci.3333-14.2015] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent studies have found that those who suffer from posttraumatic stress disorder (PTSD) are more likely to experience dementia as they age, most often Alzheimer's disease (AD). These findings suggest that the symptoms of PTSD might have an exacerbating effect on AD progression. AD and PTSD might also share common susceptibility factors such that those who experience trauma-induced disease were already more likely to succumb to dementia with age. Here, we explored these two hypotheses using a mouse model of PTSD in wild-type and AD model animals. We found that expression of human familial AD mutations in amyloid precursor protein and presenilin 1 leads to sensitivity to trauma-induced PTSD-like changes in behavioral and endocrine stress responses. PTSD-like induction, in turn, chronically elevates levels of CSF β-amyloid (Aβ), exacerbating ongoing AD pathogenesis. We show that PTSD-like induction and Aβ elevation are dependent on corticotropin-releasing factor (CRF) receptor 1 signaling and an intact hypothalamic-pituitary-adrenal axis. Furthermore, we show that Aβ species can hyperexcite CRF neurons, providing a mechanism by which Aβ influences stress-related symptoms and PTSD-like phenotypes. Consistent with Aβ causing excitability of the stress circuitry, we attenuate PTSD-like phenotypes in vivo by lowering Aβ levels during PTSD-like trauma exposure. Together, these data demonstrate that exposure to PTSD-like trauma can drive AD pathogenesis, which directly perturbs CRF signaling, thereby enhancing chronic PTSD symptoms while increasing risk for AD-related dementia.
Collapse
|
17
|
Nimmrich V, Eckert A. Calcium channel blockers and dementia. Br J Pharmacol 2014; 169:1203-10. [PMID: 23638877 DOI: 10.1111/bph.12240] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 04/15/2013] [Accepted: 04/22/2013] [Indexed: 12/25/2022] Open
Abstract
Degenerative dementia is mainly caused by Alzheimer's disease and/or cerebrovascular abnormalities. Disturbance of the intracellular calcium homeostasis is central to the pathophysiology of neurodegeneration. In Alzheimer's disease, enhanced calcium load may be brought about by extracellular accumulation of amyloid-β. Recent studies suggest that soluble forms facilitate influx through calcium-conducting ion channels in the plasma membrane, leading to excitotoxic neurodegeneration. Calcium channel blockade attenuates amyloid-β-induced neuronal decline in vitro and is neuroprotective in animal models. Vascular dementia, on the other hand, is caused by cerebral hypoperfusion and may benefit from calcium channel blockade due to relaxation of the cerebral vasculature. Several calcium channel blockers have been tested in clinical trials of dementia and the outcome is heterogeneous. Nimodipine as well as nilvadipine prevent cognitive decline in some trials, whereas other calcium channel blockers failed. In trials with a positive outcome, BP reduction did not seem to play a role in preventing dementia, indicating a direct protecting effect on neurons. An optimization of calcium channel blockers for the treatment of dementia may involve an increase of selectivity for presynaptic calcium channels and an improvement of the affinity to the inactivated state. Novel low molecular weight compounds suitable for proof-of-concept studies are now available.
Collapse
Affiliation(s)
- V Nimmrich
- Neuroscience Research, GPRD, AbbVie GmbH, Ludwigshafen, Germany.
| | | |
Collapse
|
18
|
Beggiato S, Giuliani A, Sivilia S, Lorenzini L, Antonelli T, Imbimbo B, Giardino L, Calzà L, Ferraro L. CHF5074 and LY450139 sub-acute treatments differently affect cortical extracellular glutamate levels in pre-plaque Tg2576 mice. Neuroscience 2014; 266:13-22. [DOI: 10.1016/j.neuroscience.2014.01.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/30/2014] [Accepted: 01/31/2014] [Indexed: 02/01/2023]
|
19
|
Amyloid β peptide (25–35) in picomolar concentrations modulates the function of glycine receptors in rat hippocampal pyramidal neurons through interaction with extracellular site(s). Brain Res 2014; 1558:1-10. [DOI: 10.1016/j.brainres.2014.02.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/14/2014] [Accepted: 02/17/2014] [Indexed: 01/08/2023]
|
20
|
Dao AT, Zagaar MA, Levine AT, Salim S, Eriksen JL, Alkadhi KA. Treadmill exercise prevents learning and memory impairment in Alzheimer's disease-like pathology. Curr Alzheimer Res 2014; 10:507-15. [PMID: 23627709 DOI: 10.2174/1567205011310050006] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 01/29/2013] [Accepted: 01/30/2013] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by progressive memory loss. In contrast, accumulating evidence suggests a neuroprotective role of regular exercise in aging associated memory impairment. In this study, we investigated the ability of regular exercise to prevent impairments of short-term memory (STM) and early long-term potentiation (E-LTP) in area CA1 of the hippocampus in a rat model of AD (i.c.v. infusion of 250 pmol/day Aβ1-42 peptides). We utilized behavioral assessment, in vivo electrophysiological recording, and immunoblotting in 4 groups of adult Wistar rats: control, treadmill exercise (Ex), β-amyloid-infused (Aβ), and amyloid-infused/treadmill exercised (Ex/Aβ). Our findings indicated that Aβ rats made significantly more errors in the radial arm water maze (RAWM) compared to all other groups and exhibited suppressed E-LTP in area CA1, which correlated with deleterious alterations in the levels of memory and E-LTP-related signaling molecules including calcineurin (PP2B), brain derivedneurotrophic factor (BDNF) and phosphorylated CaMKII (p-CaMKII). Compared to controls, Ex and Ex/Aβ rats showed a similar behavioral performance and a normal E-LTP with no detrimental changes in the levels of PP2B, BDNF, and p- CaMKII. We conclude that treadmill exercise maybe able to prevent cognitive impairment associated with AD pathology.
Collapse
Affiliation(s)
- An T Dao
- Department of PPS, College of Pharmacy, University of Houston, Houston, TX 77204-5037, USA
| | - Munder A Zagaar
- Texas Southern University Department of Pharmacy Practice and Clinical Health Sciences Houston, TX 77004
| | | | | | | | | |
Collapse
|
21
|
Cataldi M. The changing landscape of voltage-gated calcium channels in neurovascular disorders and in neurodegenerative diseases. Curr Neuropharmacol 2013; 11:276-97. [PMID: 24179464 PMCID: PMC3648780 DOI: 10.2174/1570159x11311030004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/02/2013] [Accepted: 02/14/2013] [Indexed: 12/12/2022] Open
Abstract
It is a common belief that voltage-gated calcium channels (VGCC) cannot carry toxic amounts of Ca2+ in neurons. Also, some of them as L-type channels are essential for Ca2+-dependent regulation of prosurvival gene-programs. However, a wealth of data show a beneficial effect of drugs acting on VGCCs in several neurodegenerative and neurovascular diseases. In the present review, we explore several mechanisms by which the “harmless” VGCCs may become “toxic” for neurons. These mechanisms could explain how, though usually required for neuronal survival, VGCCs may take part in neurodegeneration. We will present evidence showing that VGCCs can carry toxic Ca2+ when: a) their density or activity increases because of aging, chronic hypoxia or exposure to β-amyloid peptides or b) Ca2+-dependent action potentials carry high Ca2+ loads in pacemaker neurons. Besides, we will examine conditions in which VGCCs promote neuronal cell death without carrying excess Ca2+. This can happen, for instance, when they carry metal ions into the neuronal cytoplasm or when a pathological decrease in their activity weakens Ca2+-dependent prosurvival gene programs. Finally, we will explore the role of VGCCs in the control of nonneuronal cells that take part to neurodegeneration like those of the neurovascular unit or of microglia.
Collapse
Affiliation(s)
- Mauro Cataldi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, Federico II University of Naples, Italy
| |
Collapse
|
22
|
Mallmann RT, Elgueta C, Sleman F, Castonguay J, Wilmes T, van den Maagdenberg A, Klugbauer N. Ablation of Ca(V)2.1 voltage-gated Ca²⁺ channels in mouse forebrain generates multiple cognitive impairments. PLoS One 2013; 8:e78598. [PMID: 24205277 PMCID: PMC3814415 DOI: 10.1371/journal.pone.0078598] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 09/20/2013] [Indexed: 11/18/2022] Open
Abstract
Voltage-gated CaV2.1 (P/Q-type) Ca2+ channels located at the presynaptic membrane are known to control a multitude of Ca2+-dependent cellular processes such as neurotransmitter release and synaptic plasticity. Our knowledge about their contributions to complex cognitive functions, however, is restricted by the limited adequacy of existing transgenic CaV2.1 mouse models. Global CaV2.1 knock-out mice lacking the α1 subunit Cacna1a gene product exhibit early postnatal lethality which makes them unsuitable to analyse the relevance of CaV2.1 Ca2+ channels for complex behaviour in adult mice. Consequently we established a forebrain specific CaV2.1 knock-out model by crossing mice with a floxed Cacna1a gene with mice expressing Cre-recombinase under the control of the NEX promoter. This novel mouse model enabled us to investigate the contribution of CaV2.1 to complex cognitive functions, particularly learning and memory. Electrophysiological analysis allowed us to test the specificity of our conditional knock-out model and revealed an impaired synaptic transmission at hippocampal glutamatergic synapses. At the behavioural level, the forebrain-specific CaV2.1 knock-out resulted in deficits in spatial learning and reference memory, reduced recognition memory, increased exploratory behaviour and a strong attenuation of circadian rhythmicity. In summary, we present a novel conditional CaV2.1 knock-out model that is most suitable for analysing the in vivo functions of CaV2.1 in the adult murine forebrain.
Collapse
Affiliation(s)
- Robert Theodor Mallmann
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg, Germany ; Fakultät für Biologie, Albert-Ludwigs-Universität, Freiburg, Germany
| | | | | | | | | | | | | |
Collapse
|
23
|
Sepúlveda FJ, Fierro H, Fernandez E, Castillo C, Peoples RW, Opazo C, Aguayo LG. Nature of the neurotoxic membrane actions of amyloid-β on hippocampal neurons in Alzheimer's disease. Neurobiol Aging 2013; 35:472-81. [PMID: 24112789 DOI: 10.1016/j.neurobiolaging.2013.08.035] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/26/2013] [Accepted: 08/30/2013] [Indexed: 10/26/2022]
Abstract
The mechanism by which amyloid-β (Aβ) produces brain dysfunction in patients with Alzheimer's disease is largely unknown. According to previous studies, Aβ might share perforating properties with gramicidin, a well-accepted membrane-disrupting peptide. Therefore, we hypothesize that the key steps leading to synaptotoxicity by Aβ and gramicidin involve peptide aggregation, pore formation, and calcium dysregulation. Here, we show that Aβ and gramicidin form aggregates enriched in β-sheet structures using electron microscopy, and Thioflavin and Congo Red staining techniques. Also, we found that Aβ and gramicidin display fairly similar actions in hippocampal cell membranes, i.e. inducing Ca(2+) entry and synaptoxicity characterized by the loss of synaptic proteins and a decrease in neuronal viability. These effects were not observed in a Ca(2+) free solution, indicating that both Aβ and gramicidin induce neurotoxicity by a Ca(2+)-dependent mechanism. Using combined perforated patch clamp and imaging recordings, we found that only Aβ produced a perforation that progressed from a small (Cl(-)-selective pore) to a larger perforation that allowed the entry of fluorescent molecules. Therefore, based on these results, we propose that the perforation at the plasma membrane by Aβ is a dynamic process that is critical in producing neurotoxicity similar to that found in the brains of AD patients.
Collapse
Affiliation(s)
- Fernando J Sepúlveda
- Laboratory of Neurophysiology, Department of Physiology, University of Concepción, Concepción, Chile
| | | | | | | | | | | | | |
Collapse
|
24
|
Mota SI, Ferreira IL, Rego AC. Dysfunctional synapse in Alzheimer's disease - A focus on NMDA receptors. Neuropharmacology 2013; 76 Pt A:16-26. [PMID: 23973316 DOI: 10.1016/j.neuropharm.2013.08.013] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/03/2013] [Accepted: 08/08/2013] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly. Alterations capable of causing brain circuitry dysfunctions in AD may take several years to develop. Oligomeric amyloid-beta peptide (Aβ) plays a complex role in the molecular events that lead to progressive loss of function and eventually to neurodegeneration in this devastating disease. Moreover, N-methyl-D-aspartate (NMDA) receptors (NMDARs) activation has been recently implicated in AD-related synaptic dysfunction. Thus, in this review we focus on glutamatergic neurotransmission impairment and the changes in NMDAR regulation in AD, following the description on the role and location of NMDARs at pre- and post-synaptic sites under physiological conditions. In addition, considering that there is currently no effective ways to cure AD or stop its progression, we further discuss the relevance of NMDARs antagonists to prevent AD symptomatology. This review posits additional information on the role played by Aβ in AD and the importance of targeting the tripartite glutamatergic synapse in early asymptomatic and possible reversible stages of the disease through preventive and/or disease-modifying therapeutic strategies. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
Collapse
Affiliation(s)
- Sandra I Mota
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, 3004-504 Coimbra, Portugal.
| | | | | |
Collapse
|
25
|
Abstract
P/Q-type calcium channels are high-voltage-gated calcium channels contributing to vesicle release at synaptic terminals. A number of neurological diseases have been attributed to malfunctioning of P/Q channels, including ataxia, migraine and Alzheimer's disease. To date, only two specific P/Q-type blockers are known: both are peptides deriving from the spider venom of Agelenopsis aperta, ω-agatoxins. Other peptidic calcium channel blockers with activity at P/Q channels are available, albeit with less selectivity. A number of low molecular weight compounds modulate P/Q-type currents with different characteristics, and some exhibit a peculiar bidirectional pattern of modulation. Interestingly, there are a number of therapeutics in clinical use, which also show P/Q channel activity. Because selectivity as well as the exact mode of action is different between all P/Q-type channel modulators, the interpretation of clinical and experimental data is complicated and needs a comprehensive understanding of their target profile. The situation is further complicated by the fact that information on potency varies vastly in the literature, which may be the result of different experimental systems, conditions or the splice variants of the P/Q channel. This review attempts to provide a comprehensive overview of the compounds available that affect the P/Q-type channel and should help with the interpretation of results of in vitro experiments and animal models. It also aims to explain some clinical observations by implementing current knowledge about P/Q channel modulation of therapeutically used non-selective drugs. Chances and challenges of the development of P/Q channel-selective molecules are discussed.
Collapse
Affiliation(s)
- V Nimmrich
- Neuroscience Research, GPRD, Abbott, Ludwigshafen, Germany
| | | |
Collapse
|
26
|
Hermann D, Mezler M, Müller MK, Wicke K, Gross G, Draguhn A, Bruehl C, Nimmrich V. Synthetic Aβ oligomers (Aβ(1-42) globulomer) modulate presynaptic calcium currents: prevention of Aβ-induced synaptic deficits by calcium channel blockers. Eur J Pharmacol 2013; 702:44-55. [PMID: 23376566 DOI: 10.1016/j.ejphar.2013.01.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 01/14/2013] [Accepted: 01/16/2013] [Indexed: 10/27/2022]
Abstract
Alzheimer's disease is accompanied by increased brain levels of soluble amyloid-β (Aβ) oligomers. It has been suggested that oligomers directly impair synaptic function, thereby causing cognitive deficits in Alzheimer's disease patients. Recently, it has been shown that synthetic Aβ oligomers directly modulate P/Q-type calcium channels, possibly leading to excitotoxic cascades and subsequent synaptic decline. Using whole-cell recordings we studied the modulation of recombinant presynaptic calcium channels in HEK293 cells after application of a stable Aβ oligomer preparation (Aβ1-42 globulomer). Aβ globulomer shifted the half-activation voltage of P/Q-type and N-type calcium channels to more hyperpolarized values (by 11.5 and 7.5 mV). Application of non-aggregated Aβ peptides had no effect. We then analyzed the potential of calcium channel blockers to prevent Aβ globulomer-induced synaptic decline in hippocampal slice cultures. Specific block of P/Q-type or N-type calcium channels with peptide toxins completely reversed Aβ globulomer-induced deficits in glutamatergic neurotransmission. Two state-dependent low molecular weight P/Q-type and N-type calcium channel blockers also protected neurons from Aβ-induced alterations. On the contrary, inhibition of L-type calcium channels failed to reverse the deficit. Our data show that Aβ globulomer directly modulates recombinant P/Q-type and N-type calcium channels in HEK293 cells. Block of presynaptic calcium channels with both state-dependent and state-independent modulators can reverse Aβ-induced functional deficits in synaptic transmission. These findings indicate that presynaptic calcium channel blockers may be a therapeutic strategy for the treatment of Alzheimer's disease.
Collapse
Affiliation(s)
- David Hermann
- Neuroscience Research, GPRD, Abbott, 67061 Ludwigshafen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Danysz W, Parsons CG. Alzheimer's disease, β-amyloid, glutamate, NMDA receptors and memantine--searching for the connections. Br J Pharmacol 2013; 167:324-52. [PMID: 22646481 DOI: 10.1111/j.1476-5381.2012.02057.x] [Citation(s) in RCA: 335] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
β-amyloid (Aβ) is widely accepted to be one of the major pathomechanisms underlying Alzheimer's disease (AD), although there is presently lively debate regarding the relative roles of particular species/forms of this peptide. Most recent evidence indicates that soluble oligomers rather than plaques are the major cause of synaptic dysfunction and ultimately neurodegeneration. Soluble oligomeric Aβ has been shown to interact with several proteins, for example glutamatergic receptors of the NMDA type and proteins responsible for maintaining glutamate homeostasis such as uptake and release. As NMDA receptors are critically involved in neuronal plasticity including learning and memory, we felt that it would be valuable to provide an up to date review of the evidence connecting Aβ to these receptors and related neuronal plasticity. Strong support for the clinical relevance of such interactions is provided by the NMDA receptor antagonist memantine. This substance is the only NMDA receptor antagonist used clinically in the treatment of AD and therefore offers an excellent tool to facilitate translational extrapolations from in vitro studies through in vivo animal experiments to its ultimate clinical utility.
Collapse
Affiliation(s)
- Wojciech Danysz
- Merz Pharmaceuticals GmbH, Eckenheimer Landstraße, Frankfurt am Main, Germany
| | | |
Collapse
|
28
|
Parodi J, la Paz LOD, Miledi R, Martínez-Torres A. Functional and structural effects of amyloid-β aggregate on Xenopus laevis oocytes. Mol Cells 2012; 34:349-55. [PMID: 23104436 PMCID: PMC3887764 DOI: 10.1007/s10059-012-2247-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 08/22/2012] [Accepted: 09/05/2012] [Indexed: 01/04/2023] Open
Abstract
Xenopus laevis oocytes exposed to amyloid-β aggregate generated oscillatory electric activity (blips) that was recorded by two-microelectrode voltage-clamp. The cells exhibited a series of "spontaneous" blips ranging in amplitude from 3.8 ± 0.9 nA at the beginning of the recordings to 6.8 ± 1.7 nA after 15 min of exposure to 1 μM aggregate. These blips were similar in amplitude to those induced by the channel-forming antimicrobial agents amphotericin B (7.8 ± 1.2 nA) and gramicidin (6.3 ± 1.1 nA). The amyloid aggregate-induced currents were abolished when extracellular Ca(2+) was removed from the bathing solution, suggesting a central role for this cation in generating the spontaneous electric activity. The amyloid aggregate also affected the Ca(2+)-dependent Cl(-) currents of oocytes, as shown by increased amplitude of the transient-outward chloride current (T(out)) and the serum-activated, oscillatory Cl(-) currents. Electron microcopy revealed that amyloid aggregate induced the dissociation of the follicular cells that surround the oocyte, thus leading to a failure in the electro-chemical communication between these cells. This was also evidenced by the suppression of the oscillatory Ca(2+)-dependent ATP-currents, which require proper coupling between oocytes and the follicular cell layer. These observations, made using the X. laevis oocytes as a versatile experimental model, may help to understand the effects of amyloid aggregate on cellular communication.
Collapse
Affiliation(s)
- Jorge Parodi
- Laboratorio de Fisiología de la Reproducción, Núcleo de Producción Alimentaria, Escuela de Medicina, Veterinaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco,
Chile
- Laboratorio de Neurobiología Molecular y Celular, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla-Querétaro, UNAM,
México
| | - Lenin Ochoa-de la Paz
- Laboratorio de Neurobiología Molecular y Celular, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla-Querétaro, UNAM,
México
| | - Ricardo Miledi
- Laboratorio de Neurobiología Molecular y Celular, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla-Querétaro, UNAM,
México
| | - Ataúlfo Martínez-Torres
- Laboratorio de Neurobiología Molecular y Celular, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla-Querétaro, UNAM,
México
| |
Collapse
|
29
|
Russell CL, Semerdjieva S, Empson RM, Austen BM, Beesley PW, Alifragis P. Amyloid-β acts as a regulator of neurotransmitter release disrupting the interaction between synaptophysin and VAMP2. PLoS One 2012; 7:e43201. [PMID: 22905234 PMCID: PMC3419646 DOI: 10.1371/journal.pone.0043201] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 07/18/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND It is becoming increasingly evident that deficits in the cortex and hippocampus at early stages of dementia in Alzheimer's disease (AD) are associated with synaptic damage caused by oligomers of the toxic amyloid-β peptide (Aβ42). However, the underlying molecular and cellular mechanisms behind these deficits are not fully understood. Here we provide evidence of a mechanism by which Aβ42 affects synaptic transmission regulating neurotransmitter release. METHODOLOGY/FINDINGS We first showed that application of 50 nM Aβ42 in cultured neurones is followed by its internalisation and translocation to synaptic contacts. Interestingly, our results demonstrate that with time, Aβ42 can be detected at the presynaptic terminals where it interacts with Synaptophysin. Furthermore, data from dissociated hippocampal neurons as well as biochemical data provide evidence that Aβ42 disrupts the complex formed between Synaptophysin and VAMP2 increasing the amount of primed vesicles and exocytosis. Finally, electrophysiology recordings in brain slices confirmed that Aβ42 affects baseline transmission. CONCLUSIONS/SIGNIFICANCE Our observations provide a necessary and timely insight into cellular mechanisms that underlie the initial pathological events that lead to synaptic dysfunction in Alzheimer's disease. Our results demonstrate a new mechanism by which Aβ42 affects synaptic activity.
Collapse
Affiliation(s)
- Claire L. Russell
- School of Biological Sciences, Royal Holloway University London, Surrey, United Kingdom
| | - Sophia Semerdjieva
- School of Biological Sciences, Royal Holloway University London, Surrey, United Kingdom
| | - Ruth M. Empson
- School of Biological Sciences, Royal Holloway University London, Surrey, United Kingdom
- Department of Physiology, University of Otago School of Medical Sciences, Dunedin, New Zealand
| | - Brian M. Austen
- Neurodegeneration Unit, Basic Medical Sciences, St George’s, University of London, Cranmer Terrace, London, United Kingdom
| | - Philip W. Beesley
- School of Biological Sciences, Royal Holloway University London, Surrey, United Kingdom
| | - Pavlos Alifragis
- School of Biological Sciences, Royal Holloway University London, Surrey, United Kingdom
| |
Collapse
|
30
|
Yoo KY, Park SY. Terpenoids as potential anti-Alzheimer's disease therapeutics. Molecules 2012; 17:3524-38. [PMID: 22430119 PMCID: PMC6268347 DOI: 10.3390/molecules17033524] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/12/2012] [Accepted: 03/16/2012] [Indexed: 01/06/2023] Open
Abstract
Alzheimer's disease (AD) is one of the most well-known neurodegenerative diseases and explains 50-60% of dementia in patients. The prevalence rate of AD is positively correlated with age and AD affects ≥ 40% of those over 85 years old. The major AD therapeutics available on the market are acetylcholinesterase inhibitors, such as tacrine and donepezil. New therapeutic agents that can block the disease-inducing mechanisms are essential. Diverse efforts have been made to discover anti-AD agents from natural sources. In this review article, we describe some representative terpenoids such as ginsenosides, gingkolides, and canabinoids as potential anti-AD agents. These compounds exhibit promising in vitro and in vivo biological activities, but are still waiting clinical trials. Additionally, we also discuss some terpenoids including cornel iridoid glycoside, oleanolic acid, tenuifolin, cryptotanshinone, and ursolic acid, which are under investigation for their in vitro and in vivo animal studies.
Collapse
Affiliation(s)
- Ki-Yeol Yoo
- Department of Biological Sciences, College of Advanced Science, Dankook University, San#29, Anseo-dong, Dongnam-gu, Cheonan 330-714, Korea
| | - So-Young Park
- Laboratory of Pharmacognosy, College of Pharmacy, Dankook University, San#29, Anseo-dong, Dongnam-gu, Cheonan 330-714, Korea
| |
Collapse
|
31
|
Reddy PH, Shirendeb UP. Mutant huntingtin, abnormal mitochondrial dynamics, defective axonal transport of mitochondria, and selective synaptic degeneration in Huntington's disease. Biochim Biophys Acta Mol Basis Dis 2011; 1822:101-10. [PMID: 22080977 DOI: 10.1016/j.bbadis.2011.10.016] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 10/25/2011] [Accepted: 10/25/2011] [Indexed: 11/19/2022]
Abstract
Huntington's disease (HD) is a progressive, fatal neurodegenerative disease caused by expanded polyglutamine repeats in the HD gene. HD is characterized by chorea, seizures, involuntary movements, dystonia, cognitive decline, intellectual impairment and emotional disturbances. Research into mutant huntingtin (Htt) and mitochondria has found that mutant Htt interacts with the mitochondrial protein dynamin-related protein 1 (Drp1), enhances GTPase Drp1 enzymatic activity, and causes excessive mitochondrial fragmentation and abnormal distribution, leading to defective axonal transport of mitochondria and selective synaptic degeneration. This article summarizes latest developments in HD research and focuses on the role of abnormal mitochondrial dynamics and defective axonal transport in HD neurons. This article also discusses the therapeutic strategies that decrease mitochondrial fragmentation and neuronal damage in HD.
Collapse
Affiliation(s)
- P Hemachandra Reddy
- Neurogenetics Laboratory, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
| | | |
Collapse
|