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Fischer QS, Kalikulov D, Viana DI Prisco G, Williams CA, Baldwin PR, Friedlander MJ. SYNAPTIC PLASTICITY IN THE INJURED BRAIN DEPENDS ON THE TEMPORAL PATTERN OF STIMULATION. J Neurotrauma 2024. [PMID: 38818799 DOI: 10.1089/neu.2024.0129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024] Open
Abstract
Neurostimulation protocols are increasingly used as therapeutic interventions, including for brain injury. In addition to the direct activation of neurons, these stimulation protocols are also likely to have downstream effects on those neurons' synaptic outputs. It is well known that alterations in the strength of synaptic connections (long-term potentiation, LTP; long-term depression, LTD) are sensitive to the frequency of stimulation used for induction, however little is known about the contribution of the temporal pattern of stimulation to the downstream synaptic plasticity that may be induced by neurostimulation in the injured brain. We explored interactions of the temporal pattern and frequency of neurostimulation in the normal cerebral cortex and after mild traumatic brain injury (mTBI), to inform therapies to strengthen or weaken neural circuits in injured brains, as well as to better understand the role of these factors in normal brain plasticity. Whole-cell (WC) patch-clamp recordings of evoked postsynaptic potentials (PSPs) in individual neurons, as well as field potential (FP) recordings, were made from layer 2/3 of visual cortex in response to stimulation of layer 4, in acute slices from control (naïve), sham operated, and mTBI rats. We compared synaptic plasticity induced by different stimulation protocols, each consisting of a specific frequency (1 Hz, 10 Hz, or 100 Hz), continuity (continuous or discontinuous), and temporal pattern (perfectly regular, slightly irregular, or highly irregular). At the individual neuron level, dramatic differences in plasticity outcome occurred when the highly irregular stimulation protocol was used at 1 Hz or 10 Hz, producing an overall LTD in controls and shams, but a robust overall LTP after mTBI. Consistent with the individual neuron results, the plasticity outcomes for simultaneous FP recordings were similar, indicative of our results generalizing to a larger scale synaptic network than can be sampled by individual WC recordings alone. In addition to the differences in plasticity outcome between control (naïve or sham) and injured brains, the dynamics of the changes in synaptic responses that developed during stimulation were predictive of the final plasticity outcome. Our results demonstrate that the temporal pattern of stimulation plays a role in the polarity and magnitude of synaptic plasticity induced in the cerebral cortex while highlighting differences between normal and injured brain responses. Moreover, these results may be useful for optimization of neurostimulation therapies to treat mTBI and other brain disorders, in addition to providing new insights into downstream plasticity signaling mechanisms in the normal brain.
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Affiliation(s)
- Quentin S Fischer
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, United States
- Baylor College of Medicine Department of Neuroscience, Houston, Texas, United States;
| | - Djanenkhodja Kalikulov
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, United States
- Baylor College of Medicine Department of Neuroscience, Houston, Texas, United States;
| | | | - Carrie A Williams
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, United States;
| | - Philip R Baldwin
- Baylor College of Medicine Department of Neuroscience, Houston, Texas, United States;
| | - Michael J Friedlander
- Fralin Biomedical Research Institute at VTC, Roanoke, Virginia, United States
- Baylor College of Medicine Department of Neuroscience, Houston, Texas, United States;
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2
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Meloni M, Agliardi C, Guerini FR, Saibene FL, Milner AV, Zanzottera M, Bolognesi E, Puligheddu M, Figorilli M, Navarro J, Clerici M. Oligomeric Alpha-Synuclein and STX-1A from Neural-Derived Extracellular Vesicles (NDEVs) as Possible Biomarkers of REM Sleep Behavior Disorder in Parkinson's Disease: A Preliminary Cohort Study. Int J Mol Sci 2023; 24:ijms24108839. [PMID: 37240185 DOI: 10.3390/ijms24108839] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/12/2023] [Accepted: 05/13/2023] [Indexed: 05/28/2023] Open
Abstract
REM sleep behavior disorder (RBD) has a tighter link with synucleinopathies than other neurodegenerative disorders. Parkinson's Disease (PD) patients with RBD have a more severe motor and cognitive impairment; biomarkers for RBD are currently unavailable. Synaptic accumulation of α-Syn oligomers and their interaction with SNARE proteins is responsible for synaptic dysfunction in PD. We verified whether oligomeric α-Syn and SNARE components in neural-derived extracellular vesicles (NDEVs) in serum could be biomarkers for RBD. Forty-seven PD patients were enrolled, and the RBD Screening Questionnaire (RBDSQ) was compiled. A cut-off score > 6 to define probable RBD (p-RBD) and probable non-RBD (p non-RBD) was used. NDEVs were isolated from serum by immunocapture, and oligomeric α-Syn and SNARE complex components VAMP-2 and STX-1 were measured by ELISA. NDEVs' STX-1A resulted in being decreased in p-RBD compared to p non-RBD PD patients. A positive correlation between NDEVs' oligomeric α-Syn and RBDSQ total score was found (p = 0.032). Regression analysis confirmed a significant association between NDEVs' oligomeric α-Syn concentration and RBD symptoms (p = 0.033) independent from age, disease duration, and motor impairment severity. Our findings suggest that synuclein-mediated neurodegeneration in PD-RBD is more diffuse. NDEVs' oligomeric α-Syn and SNARE complex components' serum concentrations could be regarded as reliable biomarkers for the RBD-specific PD endophenotype.
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Affiliation(s)
- Mario Meloni
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy
| | | | | | | | | | | | | | - Monica Puligheddu
- Sleep Disorders Center, Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Michela Figorilli
- Sleep Disorders Center, Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Jorge Navarro
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy
| | - Mario Clerici
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
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3
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Grønnemose AL, Østerlund EC, Otzen DE, Jørgensen TJD. EGCG has Dual and Opposing Effects on the N-terminal Region of Self-associating α-synuclein Oligomers. J Mol Biol 2022; 434:167855. [PMID: 36240861 DOI: 10.1016/j.jmb.2022.167855] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/11/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
Oligomers of the protein α-synuclein (α-syn) are thought to be a major toxic species in Parkinson's disease, particularly through their ability to permeabilize cell membranes. The green tea polyphenol epigallocatechin gallate (EGCG) has been found to reduce this ability. We have analyzed α-syn oligomer dynamics and interconversion by H/D exchange monitored by mass spectrometry (HDX-MS). Our results show that the two oligomers OI and OII co-exist in equilibrium; OI is a multimer of OII and its dissociation can be followed by HDX-MS by virtue of the correlated exchange of the N-terminal region. Urea destabilizes the α-syn oligomers, dissociating OI to OII and monomers. Oligomers exposed to EGCG undergo Met oxidation. Intriguingly, EGCG induces an oxidation-dependent effect on the structure of the N-terminal region. For the non-oxidized N-terminal region, EGCG increases the stability of the folded structure as measured by a higher level of protection against H/D exchange. In contrast, protection is clearly abrogated in the Met oxidized N-terminal region. Having a non-oxidized and disordered N-terminal region is known to be essential for efficient membrane binding. Therefore, our results suggest that the combined effect of a structural stabilization of the non-oxidized N-terminal region and the presence of a disordered oxidized N-terminal region renders the oligomers less cytotoxic by decreasing the ability of the N-terminal region to bind to cell membranes and facilitate their permeabilization.
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Affiliation(s)
- Anne Louise Grønnemose
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark; Department of Biochemistry and Molecular Biology (BMB), University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Eva Christina Østerlund
- Department of Biochemistry and Molecular Biology (BMB), University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Daniel Erik Otzen
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
| | - Thomas J D Jørgensen
- Department of Biochemistry and Molecular Biology (BMB), University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
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Small soluble α-synuclein aggregates are the toxic species in Parkinson's disease. Nat Commun 2022; 13:5512. [PMID: 36127374 PMCID: PMC9489799 DOI: 10.1038/s41467-022-33252-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 09/08/2022] [Indexed: 11/08/2022] Open
Abstract
Soluble α-synuclein aggregates varying in size, structure, and morphology have been closely linked to neuronal death in Parkinson's disease. However, the heterogeneity of different co-existing aggregate species makes it hard to isolate and study their individual toxic properties. Here, we show a reliable non-perturbative method to separate a heterogeneous mixture of protein aggregates by size. We find that aggregates of wild-type α-synuclein smaller than 200 nm in length, formed during an in vitro aggregation reaction, cause inflammation and permeabilization of single-liposome membranes and that larger aggregates are less toxic. Studying soluble aggregates extracted from post-mortem human brains also reveals that these aggregates are similar in size and structure to the smaller aggregates formed in aggregation reactions in the test tube. Furthermore, we find that the soluble aggregates present in Parkinson's disease brains are smaller, largely less than 100 nm, and more inflammatory compared to the larger aggregates present in control brains. This study suggests that the small non-fibrillar α-synuclein aggregates are the critical species driving neuroinflammation and disease progression.
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5
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The Effect of Aggregated Alpha Synuclein on Synaptic and Axonal Proteins in Parkinson’s Disease—A Systematic Review. Biomolecules 2022; 12:biom12091199. [PMID: 36139038 PMCID: PMC9496556 DOI: 10.3390/biom12091199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/22/2022] [Accepted: 08/26/2022] [Indexed: 11/17/2022] Open
Abstract
α-synuclein is a core component of Lewy bodies, one of the pathological hallmarks of Parkinson’s disease. Aggregated α-synuclein can impair both synaptic functioning and axonal transport. However, understanding the pathological role that α-synuclein plays at a cellular level is complicated as existing findings are multifaceted and dependent on the mutation, the species, and the quantity of the protein that is involved. This systematic review aims to stratify the research findings to develop a more comprehensive understanding of the role of aggregated α-synuclein on synaptic and axonal proteins in Parkinson’s disease models. A literature search of the PubMed, Scopus, and Web of Science databases was conducted and a total of 39 studies were included for analysis. The review provides evidence for the dysregulation or redistribution of synaptic and axonal proteins due to α-synuclein toxicity. However, due to the high quantity of variables that were used in the research investigations, it was challenging to ascertain exactly what effect α-synuclein has on the expression of the proteins. A more standardized experimental approach regarding the variables that are employed in future studies is crucial so that existing literature can be consolidated. New research involving aggregated α-synuclein at the synapse and regarding axonal transport could be advantageous in guiding new treatment solutions.
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Dos Santos AB, Skaanning LK, Thaneshwaran S, Mikkelsen E, Romero-Leguizamón CR, Skamris T, Kristensen MP, Langkilde AE, Kohlmeier KA. Sleep-controlling neurons are sensitive and vulnerable to multiple forms of α-synuclein: implications for the early appearance of sleeping disorders in α-synucleinopathies. Cell Mol Life Sci 2022; 79:450. [PMID: 35882665 PMCID: PMC11072003 DOI: 10.1007/s00018-022-04467-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 11/03/2022]
Abstract
Parkinson's disease, Multiple System Atrophy, and Lewy Body Dementia are incurable diseases called α-synucleinopathies as they are mechanistically linked to the protein, α-synuclein (α-syn). α-syn exists in different structural forms which have been linked to clinical disease distinctions. However, sleeping disorders (SDs) are common in the prodromal phase of all three α-synucleinopathies, which suggests that sleep-controlling neurons are affected by multiple forms of α-syn. To determine whether a structure-independent neuronal impact of α-syn exists, we compared and contrasted the cellular effect of three different α-syn forms on neurotransmitter-defined cells of two sleep-controlling nuclei located in the brainstem: the laterodorsal tegmental nucleus and the pedunculopontine tegmental nucleus. We utilized size exclusion chromatography, fluorescence spectroscopy, circular dichroism spectroscopy and transmission electron microscopy to precisely characterize timepoints in the α-syn aggregation process with three different dominating forms of this protein (monomeric, oligomeric and fibril) and we conducted an in-depth investigation of the underlying neuronal mechanism behind cellular effects of the different forms of the protein using electrophysiology, multiple-cell calcium imaging, single-cell calcium imaging and live-location tracking with fluorescently-tagged α-syn. Interestingly, α-syn altered membrane currents, enhanced firing, increased intracellular calcium and facilitated cell death in a structure-independent manner in sleep-controlling nuclei, and postsynaptic actions involved a G-protein-mediated mechanism. These data are novel as the sleep-controlling nuclei are the first brain regions reported to be affected by α-syn in this structure-independent manner. These regions may represent highly important targets for future neuroprotective therapy to modify or delay disease progression in α-synucleinopathies.
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Affiliation(s)
- Altair B Dos Santos
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
- Department of Neuroscience, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Line K Skaanning
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Siganya Thaneshwaran
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Eyd Mikkelsen
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Cesar R Romero-Leguizamón
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Thomas Skamris
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | | | - Annette E Langkilde
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Kristi A Kohlmeier
- Department of Drug Design and PharmacologyFaculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark.
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7
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Wall MJ, Puddefoot K, Yin W, Bingham C, Seifi M, Swinny JD, Ngomba RT. Adenosine is released during thalamic oscillations to provide negative feedback control. Neuropharmacology 2022; 216:109172. [PMID: 35780977 DOI: 10.1016/j.neuropharm.2022.109172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 10/17/2022]
Abstract
Physiological oscillations in the cortico-thalamo-cortical loop occur during processes such as sleep, but these can become dysfunctional in pathological conditions such as absence epilepsy. The purine neuromodulator adenosine can act as an endogenous anticonvulsant: it is released into the extracellular space during convulsive seizures to activate A1 receptors suppressing on-going activity and delaying the occurrence of the next seizure. However, the role of adenosine in thalamic physiological and epileptiform oscillations is less clear. Here we have combined immunohistochemistry, electrophysiology, and fixed potential amperometry (FPA) biosensor measurements to characterise the release and actions of adenosine in thalamic oscillations measured in rodent slices. In the thalamus, A1 receptors are highly expressed particularly in the ventral basal (VB) thalamus and reticular thalamic nucleus (nRT) supporting a role for adenosine signalling in controlling oscillations. In agreement with previous studies, both adenosine and adenosine A1 receptor agonists inhibited thalamic oscillations in control (spindle-like) and in epileptic conditions. Here we have shown for the first time that both control and epileptiform oscillations are enhanced (i.e., increased number of oscillatory cycles) by blocking A1 receptors consistent with adenosine release occurring during oscillations. Although increases in extracellular adenosine could not be directly detected during control oscillations, clear increases in adenosine concentration could be detected with a biosensor during epileptiform oscillation activity. Thus, adenosine is released during thalamic oscillations and acts via A1 receptors to feedback and reduce thalamic oscillatory activity.
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Affiliation(s)
- Mark J Wall
- School of Life Sciences, University of Warwick, Coventry, UK.
| | - Katie Puddefoot
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | | | - Mohsen Seifi
- Leicester School of Pharmacy, De Montfort University, Leicester, LE1 9BH, UK
| | - Jerome D Swinny
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK
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8
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Effects of oligomer toxicity, fibril toxicity and fibril spreading in synucleinopathies. Cell Mol Life Sci 2022; 79:174. [PMID: 35244787 PMCID: PMC8897347 DOI: 10.1007/s00018-022-04166-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/17/2022] [Accepted: 01/22/2022] [Indexed: 12/18/2022]
Abstract
Protein misfolding is a general hallmark of protein deposition diseases, such as Alzheimer’s disease or Parkinson’s disease, in which different types of aggregated species (oligomers, protofibrils and fibrils) are generated by the cells. Despite widespread interest, the relationship between oligomers and fibrils in the aggregation process and spreading remains elusive. A large variety of experimental evidences supported the idea that soluble oligomeric species of different proteins might be more toxic than the larger fibrillar forms. Furthermore, the lack of correlation between the presence of the typical pathological inclusions and disease sustained this debate. However, recent data show that the β-sheet core of the α-Synuclein (αSyn) fibrils is unable to establish persistent interactions with the lipid bilayers, but they can release oligomeric species responsible for an immediate dysfunction of the recipient neurons. Reversibly, such oligomeric species could also contribute to pathogenesis via neuron-to-neuron spreading by their direct cell-to-cell transfer or by generating new fibrils, following their neuronal uptake. In this Review, we discuss the various mechanisms of cellular dysfunction caused by αSyn, including oligomer toxicity, fibril toxicity and fibril spreading.
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9
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Ramirez AE, Fernández-Pérez EJ, Olivos N, Burgos CF, Boopathi S, Armijo-Weingart L, Pacheco CR, González W, Aguayo LG. The Stimulatory Effects of Intracellular α-Synuclein on Synaptic Transmission Are Attenuated by 2-Octahydroisoquinolin-2(1H)-ylethanamine. Int J Mol Sci 2021; 22:ijms222413253. [PMID: 34948050 PMCID: PMC8705949 DOI: 10.3390/ijms222413253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
α-Synuclein (αSyn) species can be detected in synaptic boutons, where they play a crucial role in the pathogenesis of Parkinson's Disease (PD). However, the effects of intracellular αSyn species on synaptic transmission have not been thoroughly studied. Here, using patch-clamp recordings in hippocampal neurons, we report that αSyn oligomers (αSynO), intracellularly delivered through the patch electrode, produced a fast and potent effect on synaptic transmission, causing a substantial increase in the frequency, amplitude and transferred charge of spontaneous synaptic currents. We also found an increase in the frequency of miniature synaptic currents, suggesting an effect located at the presynaptic site of the synapsis. Furthermore, our in silico approximation using docking analysis and molecular dynamics simulations showed an interaction between a previously described small anti-amyloid beta (Aβ) molecule, termed M30 (2-octahydroisoquinolin-2(1H)-ylethanamine), with a central hydrophobic region of αSyn. In line with this finding, our empirical data aimed to obtain oligomerization states with thioflavin T (ThT) and Western blot (WB) indicated that M30 interfered with αSyn aggregation and decreased the formation of higher-molecular-weight species. Furthermore, the effect of αSynO on synaptic physiology was also antagonized by M30, resulting in a decrease in the frequency, amplitude, and charge transferred of synaptic currents. Overall, the present results show an excitatory effect of intracellular αSyn low molecular-weight species, not previously described, that are able to affect synaptic transmission, and the potential of a small neuroactive molecule to interfere with the aggregation process and the synaptic effect of αSyn, suggesting that M30 could be a potential therapeutic strategy for synucleinopathies.
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Affiliation(s)
- Alejandra E. Ramirez
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Eduardo J. Fernández-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
- Correspondence: (E.J.F.-P.); (L.G.A.)
| | - Nicol Olivos
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Carlos F. Burgos
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Subramanian Boopathi
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico;
- Center for Bioinformatics, Simulations and Modeling, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile;
| | - Lorena Armijo-Weingart
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Carla R. Pacheco
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Wendy González
- Center for Bioinformatics, Simulations and Modeling, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile;
- Millennium Nucleus of Ion Channels-Associated Diseases, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile
| | - Luis G. Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
- Programa de Neurociencia, Psiquiatría y Salud Mental, Anatomy Building,
Faculty of Medicine, Universidad de Concepción, Concepción 4030000, Chile
- Correspondence: (E.J.F.-P.); (L.G.A.)
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Truncating tau reveals different pathophysiological actions of oligomers in single neurons. Commun Biol 2021; 4:1265. [PMID: 34737403 PMCID: PMC8569149 DOI: 10.1038/s42003-021-02791-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/14/2021] [Indexed: 11/18/2022] Open
Abstract
Tau protein is involved in maintaining neuronal structure. In Alzheimer’s disease, small numbers of tau molecules can aggregate to form oligomers. However, how these oligomers produce changes in neuronal function remains unclear. Previously, oligomers made from full-length human tau were found to have multiple effects on neuronal properties. Here we have cut the tau molecule into two parts: the first 123 amino acids and the remaining 124-441 amino acids. These truncated tau molecules had specific effects on neuronal properties, allowing us to assign the actions of full-length tau to different regions of the molecule. We identified one key target for the effects of tau, the voltage gated sodium channel, which could account for the effects of tau on the action potential. By truncating the tau molecule, we have probed the mechanisms that underlie tau dysfunction, and this increased understanding of tau’s pathological actions will build towards developing future tau-targeting therapies. Hill et al. examine the effects of full-length or truncated human recombinant tau on the excitability of hippocampal pyramidal neurons in mice. Their results suggest that effects seen with full-length tau oligomers can be dissected apart using tau truncations and highlights a tau-mediated alteration in voltage-gated sodium channel currents.
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11
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Complicity of α-synuclein oligomer and calcium dyshomeostasis in selective neuronal vulnerability in Lewy body disease. Arch Pharm Res 2021; 44:564-573. [PMID: 34114191 PMCID: PMC8254713 DOI: 10.1007/s12272-021-01334-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/27/2021] [Indexed: 11/18/2022]
Abstract
α-Synuclein oligomers and Ca2+ dyshomeostasis have been thoroughly investigated with respect to the pathogenesis of Lewy body disease (LBD). In LBD, α-synuclein oligomers exhibit a neuron-specific cytoplasmic distribution. Highly active neurons and neurons with a high Ca2+ burden are prone to damage in LBD. The neuronal vulnerability may be determined by transneuronal axonal transmission of the pathological processes; however, this hypothesis seems inconsistent with pathological findings that neurons anatomically connected to LBD-vulnerable neurons, such as neurons in the ventral tegmentum, are spared in LBD. This review focuses on and discusses the crucial roles played by α-synuclein oligomers and Ca2+ dyshomeostasis in early intraneural pathophysiology in LBD-vulnerable neurons. A challenging view is proposed on the synergy between retrograde transport of α-synuclein and vesicular Ca release, whereby neuronal vulnerability is propagated backward along repeatedly activated signaling pathway.
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12
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α-Synuclein Aggregates Increase the Conductance of Substantia Nigra Dopamine Neurons, an Effect Partly Reversed by the KATP Channel Inhibitor Glibenclamide. eNeuro 2021; 8:ENEURO.0330-20.2020. [PMID: 33229413 PMCID: PMC7810260 DOI: 10.1523/eneuro.0330-20.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 10/13/2020] [Accepted: 10/18/2020] [Indexed: 01/06/2023] Open
Abstract
Dopaminergic neurons (DNs) in the substantia nigra pars compacta (SNpc) form an important part of the basal ganglia circuitry, playing key roles in movement initiation and coordination. A hallmark of Parkinson’s disease (PD) is the degeneration of these SNpc DNs leading to akinesia, bradykinesia and tremor. There is gathering evidence that oligomeric α-synuclein (α-syn) is one of the major pathologic species in PD, with its deposition in Lewy bodies (LBs) closely correlated with disease progression. However, the precise mechanisms underlying the effects of oligomeric α-syn on DN function have yet to be fully defined. Here, we have combined electrophysiological recording and detailed analysis to characterize the time-dependent effects of α-syn aggregates (consisting of oligomers and possibly small fibrils) on the properties of SNpc DNs. The introduction of α-syn aggregates into single DNs via the patch electrode significantly reduced both the input resistance and the firing rate without changing the membrane potential. These effects occurred after 8–16 min of dialysis but did not occur with the monomeric form of α-syn. The effects of α-syn aggregates could be significantly reduced by preincubation with the ATP-sensitive K+ channel (KATP) inhibitor glibenclamide. These data suggest that accumulation of α-syn aggregates in DNs may chronically activate KATP channels leading to a significant loss of excitability and dopamine release.
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Agliardi C, Meloni M, Guerini FR, Zanzottera M, Bolognesi E, Baglio F, Clerici M. Oligomeric α-Syn and SNARE complex proteins in peripheral extracellular vesicles of neural origin are biomarkers for Parkinson's disease. Neurobiol Dis 2020; 148:105185. [PMID: 33217562 DOI: 10.1016/j.nbd.2020.105185] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/22/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023] Open
Abstract
Blood-based biomarkers are needed to be used as easy, reproducible, and non-invasive tools for the diagnosis and prognosis of chronic neurodegenerative disorders including Parkinson's Disease (PD). In PD, aggregated toxic forms of α-Synuclein (α-Syn) accumulate within neurons in the brain and cause neurodegeneration; α-Syn interaction with SNARE proteins also results in synaptic disfunction. We isolated neural derived extravesicles (NDEs) from peripheral blood of 32 PD patients and 40 healthy controls (HC) and measured the concentrations of oligomeric α-Syn and of the presinaptic SNARE complex proteins: STX-1A, VAMP-2 and SNAP-25. Oligomeric α-Syn was significantly augmented whereas STX-1A and VAMP-2 were significantly reduced in NDEs of PD patients compared to HC (p < 0.001 in all cases). ROC curve analyses confirmed the discriminatory ability of NDEs oligomeric α-Syn, STX-1A and VAMP-2 levels to distinguish between PD patients and HC. Oligomeric α-Syn NDEs concentration also positively correlated with disease duration and severity of PD. These results are promising and confirm that NDEs cargoes likely reflect core pathogenic intracellular processes in their originating brain cells and could serve as novel easily accessible bio-markers. Further studies are needed to confirm results and eventually for testing rehabilitation programs and drug treatments effects.
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Affiliation(s)
| | - Mario Meloni
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy
| | | | | | | | | | - Mario Clerici
- IRCCS Fondazione Don Carlo Gnocchi ONLUS, 20148 Milan, Italy; Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
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14
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Kumar ST, Jagannath S, Francois C, Vanderstichele H, Stoops E, Lashuel HA. How specific are the conformation-specific α-synuclein antibodies? Characterization and validation of 16 α-synuclein conformation-specific antibodies using well-characterized preparations of α-synuclein monomers, fibrils and oligomers with distinct structures and morphology. Neurobiol Dis 2020; 146:105086. [PMID: 32971232 DOI: 10.1016/j.nbd.2020.105086] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/30/2020] [Accepted: 09/17/2020] [Indexed: 12/14/2022] Open
Abstract
Increasing evidence suggests that alpha-synuclein (α-syn) oligomers are obligate intermediates in the pathway involved in α-syn fibrillization and Lewy body (LB) formation, and may also accumulate within LBs in Parkinson's disease (PD) and other synucleinopathies. Therefore, the development of tools and methods to detect and quantify α-syn oligomers has become increasingly crucial for mechanistic studies to understand their role in PD, and to develop new diagnostic methods and therapies for PD and other synucleinopathies. The majority of these tools and methods rely primarily on the use of aggregation state-specific or conformation-specific antibodies. Given the impact of the data and knowledge generated using these antibodies on shaping the foundation and directions of α-syn and PD research, it is crucial that these antibodies are thoroughly characterized, and their specificity or ability to capture diverse α-syn species is tested and validated. Herein, we describe an antibody characterization and validation pipeline that allows a systematic investigation of the specificity of α-syn antibodies using well-defined and well-characterized preparations of various α-syn species, including monomers, fibrils, and different oligomer preparations that are characterized by distinct morphological, chemical and secondary structure properties. This pipeline was used to characterize 18 α-syn antibodies, 16 of which have been reported as conformation- or oligomer-specific antibodies, using an array of techniques, including immunoblot analysis (slot blot and Western blot), a digital ELISA assay using single molecule array technology and surface plasmon resonance. Our results show that i) none of the antibodies tested are specific for one particular type of α-syn species, including monomers, oligomers or fibrils; ii) all antibodies that were reported to be oligomer-specific also recognized fibrillar α-syn; and iii) a few antibodies showed high specificity for oligomers and fibrils but did not bind to monomers. These findings suggest that the great majority of α-syn aggregate-specific antibodies do not differentiate between oligomers and fibrils, thus highlighting the importance of exercising caution when interpreting results obtained using these antibodies. Our results also underscore the critical importance of the characterization and validation of antibodies before their use in mechanistic studies and as diagnostic tools or therapeutic agents. This will not only improve the quality and reproducibility of research and reduce costs but will also reduce the number of therapeutic antibody failures in the clinic.
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Affiliation(s)
- Senthil T Kumar
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, EPFL, Switzerland
| | - Somanath Jagannath
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, EPFL, Switzerland
| | | | - Hugo Vanderstichele
- ADx NeuroSciences, Technologiepark 94, Ghent, Belgium; Biomarkable, Gent, Belgium
| | - Erik Stoops
- ADx NeuroSciences, Technologiepark 94, Ghent, Belgium
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, EPFL, Switzerland.
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15
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Hill E, Wall MJ, Moffat KG, Karikari TK. Understanding the Pathophysiological Actions of Tau Oligomers: A Critical Review of Current Electrophysiological Approaches. Front Mol Neurosci 2020; 13:155. [PMID: 32973448 PMCID: PMC7468384 DOI: 10.3389/fnmol.2020.00155] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/28/2020] [Indexed: 12/22/2022] Open
Abstract
Tau is a predominantly neuronal protein that is normally bound to microtubules, where it acts to modulate neuronal and axonal stability. In humans, pathological forms of tau are implicated in a range of diseases that are collectively known as tauopathies. Kinases and phosphatases are responsible for maintaining the correct balance of tau phosphorylation to enable axons to be both stable and labile enough to function properly. In the early stages of tauopathies, this balance is interrupted leading to dissociation of tau from microtubules. This leaves microtubules prone to damage and phosphorylated tau prone to aggregation. Initially, phosphorylated tau forms oligomers, then fibrils, and ultimately neurofibrillary tangles (NFTs). It is widely accepted that the initial soluble oligomeric forms of tau are probably the most pathologically relevant species but there is relatively little quantitative information to explain exactly what their toxic effects are at the individual neuron level. Electrophysiology provides a valuable tool to help uncover the mechanisms of action of tau oligomers on synaptic transmission within single neurons. Understanding the concentration-, time-, and neuronal compartment-dependent actions of soluble tau oligomers on neuronal and synaptic properties are essential to understanding how best to counteract its effects and to develop effective treatment strategies. Here, we briefly discuss the standard approaches used to elucidate these actions, focusing on the advantages and shortcomings of the experimental procedures. Subsequently, we will describe a new approach that addresses specific challenges with the current methods, thus allowing real-time toxicity evaluation at the single-neuron level.
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Affiliation(s)
- Emily Hill
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Mark J Wall
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Kevin G Moffat
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Thomas K Karikari
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
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16
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Yang N, Li Z, Han D, Mi X, Tian M, Liu T, Li Y, He J, Kuang C, Cao Y, Li L, Ni C, Wang JQ, Guo X. Autophagy prevents hippocampal α-synuclein oligomerization and early cognitive dysfunction after anesthesia/surgery in aged rats. Aging (Albany NY) 2020; 12:7262-7281. [PMID: 32335546 PMCID: PMC7202547 DOI: 10.18632/aging.103074] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 03/29/2020] [Indexed: 12/13/2022]
Abstract
Stress-induced α-synuclein aggregation, especially the most toxic species (oligomers), may precede synaptic and cognitive dysfunction. Under pathological conditions, α-synuclein is degraded primarily through the autophagic/lysosomal pathway. We assessed the involvement of autophagy in α-synuclein aggregation and cognitive impairment following general anesthesia and surgical stress. Autophagy was found to be suppressed in the aged rat hippocampus after either 4-h propofol anesthesia alone or 2-h propofol anesthesia during a laparotomy surgery. This inhibition of autophagy was accompanied by profound α-synuclein oligomer aggregation and neurotransmitter imbalances in the hippocampus, along with hippocampus-dependent cognitive deficits. These events were not observed 18 weeks after propofol exposure with or without surgical stress. The pharmacological induction of autophagy using rapamycin markedly suppressed α-synuclein oligomerization, restored neurotransmitter equilibrium, and improved cognitive behavior after prolonged anesthesia or anesthesia combined with surgery. Thus, both prolonged propofol anesthesia alone and propofol anesthesia during surgery impaired autophagy, which may have induced abnormal hippocampal α-synuclein aggregation and neurobehavioral deficits in aged rats. These findings suggest that the activation of autophagy and the clearance of pathological α-synuclein oligomers may be novel strategies to ameliorate the common occurrence of postoperative cognitive dysfunction.
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Affiliation(s)
- Ning Yang
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Zhengqian Li
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Dengyang Han
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Xinning Mi
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Miao Tian
- Chinese Traditional and Herbal Drugs Editorial Office, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China
| | - Taotao Liu
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Yue Li
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Jindan He
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Chongshen Kuang
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - Yiyun Cao
- Department of Anesthesiology, Shanghai Sixth People's Hospital East Affiliated with Shanghai University of Medicine and Health Sciences, Shanghai 200233, China
| | - Lunxu Li
- Department of Anesthesiology, Peking University International Hospital, Beijing 102200, China
| | - Cheng Ni
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
| | - John Q Wang
- Department of Anesthesiology, University of Missouri Kansas City, School of Medicine, Kansas, MO 64110, USA
| | - Xiangyang Guo
- Department of Anesthesiology, Peking University Third Hospital, Beijing 100191, China
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Alpha-synuclein differentially reduces surface expression of N-methyl-d-aspartate receptors in the aging human brain. Neurobiol Aging 2020; 90:24-32. [PMID: 32171588 DOI: 10.1016/j.neurobiolaging.2020.02.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/21/2020] [Accepted: 02/13/2020] [Indexed: 01/22/2023]
Abstract
The aging brain is associated with reduced cell surface expression of N-methyl-d-aspartate receptors (NMDARs), but the mechanism remains poorly understood. In the present study, we showed that in the striatum and hippocampus but not the cerebellum and parietal cortex, levels of α-synuclein monomers and oligomers increased with age, which correlated negatively with the expression of GluN1, and positively with the expression of total Rab5B. The oligomer-α-synuclein exhibited a stronger correlation with the expression of surface GluN1 and total Rab5B. In MES23.5 cells, the monomer- or oligomer-α-synuclein were shown to increase in a manner dependent on the concentrations of the added monomers and oligomers. Again, the oligomer-α-synuclein showed more potent effects than the monomer-α-synuclein on surface GluN1 and total Rab5B expression. Accordingly, the oligomer-treated cells showed a greater reduction in NMDA-evoked Ca2+ influx than the monomer-treated cells, which was largely inhibited by pistop2, a clathrin inhibitor. These results suggest that the age-dependent accumulation of α-synuclein monomers and oligomers differentially contributes to the reduction in surface NMDAR expression in selective brain regions.
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18
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Yamamoto K, Izumi Y, Arifuku M, Kume T, Sawada H. α-Synuclein oligomers mediate the aberrant form of spike-induced calcium release from IP 3 receptor. Sci Rep 2019; 9:15977. [PMID: 31685859 PMCID: PMC6828767 DOI: 10.1038/s41598-019-52135-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/12/2019] [Indexed: 01/10/2023] Open
Abstract
Emerging evidence implicates α-synuclein oligomers as potential culprits in the pathogenesis of Lewy body disease (LBD). Soluble oligomeric α-synuclein accumulation in cytoplasm is believed to modify neuronal activities and intraneural Ca2+ dynamics, which augment the metabolic burden in central neurons vulnerable to LBD, although this hypothesis remains to be fully tested. We evaluated how intracellular α-synuclein oligomers affect the neuronal excitabilities and Ca2+ dynamics of pyramidal neurons in neocortical slices from mice. Intracellular application of α-synuclein containing stable higher-order oligomers (αSNo) significantly reduced spike frequency during current injection, elongated the duration of spike afterhyperpolarization (AHP), and enlarged AHP current charge in comparison with that of α-synuclein without higher-order oligomers. This αSNo-mediated alteration was triggered by spike-induced Ca2+ release from inositol trisphosphate receptors (IP3R) functionally coupled with L-type Ca2+ channels and SK-type K+ channels. Further electrophysiological and immunochemical observations revealed that α-synuclein oligomers greater than 100 kDa were directly associated with calcium-binding protein 1, which is responsible for regulating IP3R gating. They also block Ca2+-dependent inactivation of IP3R, and trigger Ca2+-induced Ca2+ release from IP3R during multiple spikes. This aberrant machinery may result in intraneural Ca2+ dyshomeostasis and may be the molecular basis for the vulnerability of neurons in LBD brains.
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Affiliation(s)
- Kenji Yamamoto
- Department of Neurology and Clinical Research Center, National Hospital Organization Utano National Hospital, Kyoto, Japan.
| | - Yasuhiko Izumi
- Laboratory of Pharmacology, Kobe Pharmaceutical University, Kobe, Japan.,Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Monami Arifuku
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Toshiaki Kume
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.,Department of Applied Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Hideyuki Sawada
- Department of Neurology and Clinical Research Center, National Hospital Organization Utano National Hospital, Kyoto, Japan
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19
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Introduction of Tau Oligomers into Cortical Neurons Alters Action Potential Dynamics and Disrupts Synaptic Transmission and Plasticity. eNeuro 2019; 6:ENEURO.0166-19.2019. [PMID: 31554666 PMCID: PMC6794083 DOI: 10.1523/eneuro.0166-19.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/29/2019] [Accepted: 09/12/2019] [Indexed: 01/08/2023] Open
Abstract
Tau is a highly soluble microtubule-associated protein that acts within neurons to modify microtubule stability. However, abnormally phosphorylated tau dissociates from microtubules to form oligomers and fibrils which associate in the somatodendritic compartment. Although tau can form neurofibrillary tangles (NFTs), it is the soluble oligomers that appear to be the toxic species. There is, however, relatively little quantitative information on the concentration-dependent and time-dependent actions of soluble tau oligomers (oTau) on the electrophysiological and synaptic properties of neurons. Here, whole-cell patch clamp recording was used to introduce known concentrations of oligomeric full-length tau-441 into mouse hippocampal CA1 pyramidal and neocortical Layer V thick-tufted pyramidal cells. oTau increased input resistance, reduced action potential amplitude and slowed action potential rise and decay kinetics. oTau injected into presynaptic neurons induced the run-down of unitary EPSPs which was associated with increased short-term depression. In contrast, introduction of oTau into postsynaptic neurons had no effect on basal synaptic transmission, but markedly impaired the induction of long-term potentiation (LTP). Consistent with its effects on synaptic transmission and plasticity, oTau puncta could be observed in the soma, axon and in the distal dendrites of injected neurons.
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20
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α-Synuclein 2.0 — Moving towards Cell Type Specific Pathophysiology. Neuroscience 2019; 412:248-256. [DOI: 10.1016/j.neuroscience.2019.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/17/2022]
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21
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van Diggelen F, Hrle D, Apetri M, Christiansen G, Rammes G, Tepper A, Otzen DE. Two conformationally distinct α-synuclein oligomers share common epitopes and the ability to impair long-term potentiation. PLoS One 2019; 14:e0213663. [PMID: 30901378 PMCID: PMC6430514 DOI: 10.1371/journal.pone.0213663] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/26/2019] [Indexed: 02/01/2023] Open
Abstract
Parkinson’s Disease (PD) is a neurodegenerative disease for which there currently is no cure. Aggregation of the pre-synaptic protein α-synuclein (aSN) into oligomers (αSOs) is believed to play a key role in PD pathology, but little is known about αSO formation in vivo and how they induce neurodegeneration. Both the naturally occurring polyunsaturated fatty acid docosahexaenoic acid (DHA) and the lipid peroxidation product 4-hydroxynonenal (HNE), strongly upregulated during ROS conditions, stimulate the formation of αSOs, highlighting a potential role in PD. Yet, insight into αSOs structure and biological effects is still limited as most oligomer preparations studied to date are heterogeneous in composition. Here we have aggregated aSN in the presence of HNE and DHA and purified the αSOs using size exclusion chromatography. Both compounds stimulate formation of spherical αSOs containing anti-parallel β-sheet structure which have the same shape as unmodified αSOs though ca. 2-fold larger. Furthermore, the yield and stabilities of these oligomers are significantly higher than for unmodified aSN. Both modified and unmodified αSOs permeabilize synthetic vesicles, show high co-localisation with glutamatergic synapses and decrease Long Term Potentiation (LTP), in line with the reported synaptotoxic effects of αSOs. We conclude that DHA- and HNE-αSOs are convenient models for pathogenic disease-associated αSOs in PD.
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Affiliation(s)
- Femke van Diggelen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
- Crossbeta Biosciences BV, Utrecht, The Netherlands
| | - Dean Hrle
- Klinik für Anaesthesiologie der Technischen Universität München, Klinikum Rechts der Isar, Munich, Germany
| | | | | | - Gerhard Rammes
- Klinik für Anaesthesiologie der Technischen Universität München, Klinikum Rechts der Isar, Munich, Germany
| | | | - Daniel Erik Otzen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark
- * E-mail:
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22
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Gribaudo S, Tixador P, Bousset L, Fenyi A, Lino P, Melki R, Peyrin JM, Perrier AL. Propagation of α-Synuclein Strains within Human Reconstructed Neuronal Network. Stem Cell Reports 2019; 12:230-244. [PMID: 30639210 PMCID: PMC6372945 DOI: 10.1016/j.stemcr.2018.12.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 12/11/2018] [Accepted: 12/11/2018] [Indexed: 01/01/2023] Open
Abstract
Reappraisal of neuropathological studies suggests that pathological hallmarks of Alzheimer’s disease and Parkinson’s disease (PD) spread progressively along predictable neuronal pathways in the human brain through unknown mechanisms. Although there is much evidence supporting the prion-like propagation and amplification of α-synuclein (α-Syn) in vitro and in rodent models, whether this scenario occurs in the human brain remains to be substantiated. Here we reconstructed in microfluidic devices corticocortical neuronal networks using human induced pluripotent stem cells derived from a healthy donor. We provide unique experimental evidence that different strains of human α-Syn disseminate in “wild-type” human neuronal networks in a prion-like manner. We show that two distinct α-Syn strains we named fibrils and ribbons are transported, traffic between neurons, and trigger to different extents, in a dose- and structure-dependent manner, the progressive accumulation of PD-like pathological hallmarks. We further demonstrate that seeded aggregation of endogenous soluble α-Syn affects synaptic integrity and mitochondria morphology. Different α-Syn strains propagate within WT human iPSC-derived cortical neuronal networks α-Syn strains differentially seed endogenous WT α-Syn forming LB/LN-like structures Phospho-α-Syn endogenous aggregates resist degradation and accumulate in cytoplasm Accumulation of phospho-α-Syn induces early neuronal dysfunctions
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Affiliation(s)
- Simona Gribaudo
- INSERM U861, I-STEM, AFM, Corbeil-Essonnes 91100, France; UEVE U861, I-STEM, AFM, Corbeil-Essonnes 91100, France
| | - Philippe Tixador
- Sorbonne Universités, Faculté des Sciences et Ingénierie, CNRS/UMR 8256, B2A, Biological Adaptation and Ageing, Institut de Biologie Paris Seine, Paris 75005, France
| | - Luc Bousset
- Laboratory of Neurodegenerative Disease, Institut François Jacob, MIRCen, CEA-CNRS, Fontenay aux Roses 92265, France
| | - Alexis Fenyi
- Laboratory of Neurodegenerative Disease, Institut François Jacob, MIRCen, CEA-CNRS, Fontenay aux Roses 92265, France
| | - Patricia Lino
- INSERM U861, I-STEM, AFM, Corbeil-Essonnes 91100, France; UEVE U861, I-STEM, AFM, Corbeil-Essonnes 91100, France
| | - Ronald Melki
- Laboratory of Neurodegenerative Disease, Institut François Jacob, MIRCen, CEA-CNRS, Fontenay aux Roses 92265, France.
| | - Jean-Michel Peyrin
- Sorbonne Universités, Faculté des Sciences et Ingénierie, CNRS/UMR 8256, B2A, Biological Adaptation and Ageing, Institut de Biologie Paris Seine, Paris 75005, France.
| | - Anselme L Perrier
- INSERM U861, I-STEM, AFM, Corbeil-Essonnes 91100, France; UEVE U861, I-STEM, AFM, Corbeil-Essonnes 91100, France.
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Yu W, Yang W, Li X, Li X, Yu S. Alpha-synuclein oligomerization increases its effect on promoting NMDA receptor internalization. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:87-100. [PMID: 31933723 PMCID: PMC6944010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/26/2018] [Indexed: 06/10/2023]
Abstract
The internalization of NMDA receptors (NMDARs) is promoted by monomeric α-synuclein (α-syn). Because of the pathogenic role of oligomeric α-syn, the effect of aggregated α-syn on this regulation deserves investigation. Several α-syn oligomers were prepared by incubating recombinant human α-syn in phosphate-buffered saline (PBS), plasma of normal controls (NC) and patients with Parkinson's disease (PD). The α-syn oligomers formed in PBS are not phosphorylated and are different from the α-syn oligomers formed in the plasma of NC and PD that are moderately and highly phosphorylated at serine 129, which is a key phosphorylation site of the α-syn molecule in PD patients. After being added into the culture medium, the α-syn monomers and its oligomers formed in different methods and rapidly entered into MES23.5 dopaminergic cells and induced an increase in the expression of Rab5B, an endocytic protein that has been shown to regulate clathrin-mediated endocytosis of NMDARs. The levels of surface GluN1, a subunit obligatory for the assembly of functional NMDAR, were reduced, but the total GluN1 changes didn't show a parallel reduction of the surface of GluN1, indicating the internalization of GluN1. Compared with the monomers, the oligomers, especially those formed in PD plasma, were more potent in promoting GluN1 internalization, and were abolished by clathrin inhibitor pitstop2. The above results suggest that α-syn oligomers, especially those formed in PD plasma, increase the effect of α-syn in promoting the internalization of NMDAR GluN1 subunits, possibly through a clathrin-mediated endocytic mechanism.
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Affiliation(s)
- Wenjiao Yu
- Department of Neurobiology, Xuanwu Hospital of Capital Medical UniversityBeijing, China
- Clinical Center for Parkinson’s Disease, Capital Medical UniversityBeijing, China
- National Clinical Research Center for Geriatric DisordersBeijing, China
- Parkinson Disease Center of Beijing Institute for Brain DisordersBeijing, China
| | - Weiwei Yang
- Department of Neurobiology, Xuanwu Hospital of Capital Medical UniversityBeijing, China
- Clinical Center for Parkinson’s Disease, Capital Medical UniversityBeijing, China
- National Clinical Research Center for Geriatric DisordersBeijing, China
- Parkinson Disease Center of Beijing Institute for Brain DisordersBeijing, China
| | - Xuran Li
- Department of Neurobiology, Xuanwu Hospital of Capital Medical UniversityBeijing, China
- Clinical Center for Parkinson’s Disease, Capital Medical UniversityBeijing, China
- National Clinical Research Center for Geriatric DisordersBeijing, China
- Parkinson Disease Center of Beijing Institute for Brain DisordersBeijing, China
| | - Xin Li
- Department of Neurobiology, Xuanwu Hospital of Capital Medical UniversityBeijing, China
- Clinical Center for Parkinson’s Disease, Capital Medical UniversityBeijing, China
- National Clinical Research Center for Geriatric DisordersBeijing, China
- Parkinson Disease Center of Beijing Institute for Brain DisordersBeijing, China
| | - Shun Yu
- Department of Neurobiology, Xuanwu Hospital of Capital Medical UniversityBeijing, China
- Clinical Center for Parkinson’s Disease, Capital Medical UniversityBeijing, China
- National Clinical Research Center for Geriatric DisordersBeijing, China
- Parkinson Disease Center of Beijing Institute for Brain DisordersBeijing, China
- Beijing Key Laboratory for Parkinson’s DiseaseBeijing, China
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Zhang G, Xia Y, Wan F, Ma K, Guo X, Kou L, Yin S, Han C, Liu L, Huang J, Xiong N, Wang T. New Perspectives on Roles of Alpha-Synuclein in Parkinson's Disease. Front Aging Neurosci 2018; 10:370. [PMID: 30524265 PMCID: PMC6261981 DOI: 10.3389/fnagi.2018.00370] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/25/2018] [Indexed: 01/07/2023] Open
Abstract
Parkinson’s disease (PD) is one of the synucleinopathies spectrum of disorders typified by the presence of intraneuronal protein inclusions. It is primarily composed of misfolded and aggregated forms of alpha-synuclein (α-syn), the toxicity of which has been attributed to the transition from an α-helical conformation to a β-sheetrich structure that polymerizes to form toxic oligomers. This could spread and initiate the formation of “LB-like aggregates,” by transcellular mechanisms with seeding and subsequent permissive templating. This hypothesis postulates that α-syn is a prion-like pathological agent and responsible for the progression of Parkinson’s pathology. Moreover, the involvement of the inflammatory response in PD pathogenesis has been reported on the excessive microglial activation and production of pro-inflammatory cytokines. At last, we describe several treatment approaches that target the pathogenic α-syn protein, especially the oligomers, which are currently being tested in advanced animal experiments or are already in clinical trials. However, there are current challenges with therapies that target α-syn, for example, difficulties in identifying varying α-syn conformations within different individuals as well as both the cost and need of long-duration large trials.
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Affiliation(s)
- Guoxin Zhang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yun Xia
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Wan
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kai Ma
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingfang Guo
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liang Kou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sijia Yin
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chao Han
- Department of Neurology, Anhui Provincial Hospital, The First Affiliated Hospital of Science and Technology of China, Hefei, China
| | - Ling Liu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jinsha Huang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Nian Xiong
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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25
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Kundel F, Tosatto L, Whiten DR, Wirthensohn DC, Horrocks MH, Klenerman D. Shedding light on aberrant interactions - a review of modern tools for studying protein aggregates. FEBS J 2018; 285:3604-3630. [PMID: 29453901 DOI: 10.1111/febs.14409] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/27/2018] [Accepted: 02/12/2018] [Indexed: 12/15/2022]
Abstract
The link between protein aggregation and neurodegenerative disease is well established. However, given the heterogeneity of species formed during the aggregation process, it is difficult to delineate details of the molecular events involved in generating pathological aggregates from those producing soluble monomers. As aberrant aggregates are possible pharmacological targets for the treatment of neurodegenerative diseases, the need to observe and characterise soluble oligomers has pushed traditional biophysical techniques to their limits, leading to the development of a plethora of new tools capable of detecting soluble oligomers with high precision and specificity. In this review, we discuss a range of modern biophysical techniques that have been developed to study protein aggregation, and give an overview of how they have been used to understand, in detail, the aberrant aggregation of amyloidogenic proteins associated with the two most common neurodegenerative disorders, Alzheimer's disease and Parkinson's disease.
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Affiliation(s)
| | - Laura Tosatto
- Centre for Integrative Biology, Università degli Studi di Trento, Italy
| | | | | | | | - David Klenerman
- Department of Chemistry, University of Cambridge, UK.,UK Dementia Research Institute, University of Cambridge, UK
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26
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Miraglia F, Ricci A, Rota L, Colla E. Subcellular localization of alpha-synuclein aggregates and their interaction with membranes. Neural Regen Res 2018; 13:1136-1144. [PMID: 30028312 PMCID: PMC6065224 DOI: 10.4103/1673-5374.235013] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
For more than a decade numerous evidence has been reported on the mechanisms of toxicity of α-synuclein (αS) oligomers and aggregates in α-synucleinopathies. These species were thought to form freely in the cytoplasm but recent reports of αS multimer conformations when bound to synaptic vesicles in physiological conditions, have raised the question about where αS aggregation initiates. In this review we focus on recent literature regarding the impact on membrane binding and subcellular localization of αS toxic species to understand how regular cellular function of αS contributes to pathology. Notably αS has been reported to mainly associate with specific membranes in neurons such as those of synaptic vesicles, ER/Golgi and the mitochondria, while toxic species of αS have been shown to inhibit, among others, neurotransmission, protein trafficking and mitochondrial function. Strategies interfering with αS membrane binding have shown to improve αS-driven toxicity in worms and in mice. Thus, a selective membrane binding that would result in a specific subcellular localization could be the key to understand how aggregation and pathology evolves, pointing out to αS functions that are primarily affected before onset of irreversible damage.
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Affiliation(s)
- Fabiana Miraglia
- Bio@SNS Laboratory, Scuola Normale Superiore, Pisa; Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Alessio Ricci
- Bio@SNS Laboratory, Scuola Normale Superiore, Pisa, Italy
| | - Lucia Rota
- Bio@SNS Laboratory, Scuola Normale Superiore, Pisa, Italy
| | - Emanuela Colla
- Bio@SNS Laboratory, Scuola Normale Superiore, Pisa, Italy
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27
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Bengoa-Vergniory N, Roberts RF, Wade-Martins R, Alegre-Abarrategui J. Alpha-synuclein oligomers: a new hope. Acta Neuropathol 2017; 134:819-838. [PMID: 28803412 PMCID: PMC5663814 DOI: 10.1007/s00401-017-1755-1] [Citation(s) in RCA: 220] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/21/2017] [Accepted: 07/22/2017] [Indexed: 01/22/2023]
Abstract
Alpha-synuclein is a protein implicated in Parkinson’s disease and thought to be one of the main pathological drivers in the disease, although it remains unclear how this protein elicits its neurotoxic effects. Recent findings indicate that the assembly of toxic oligomeric species of alpha-synuclein may be one of the key processes for the pathology and spread of the disease. The absence of a sensitive in situ detection method has hindered the study of these oligomeric species and the role they play in the human brain until recently. In this review, we assess the evidence for the toxicity and prion-like activity of oligomeric forms of alpha-synuclein and discuss the advances in our understanding of the role of alpha-synuclein in Parkinson’s disease that may be brought about by the specific and sensitive detection of distinct oligomeric species in post-mortem patient brain. Finally, we discuss current approaches being taken to therapeutically target alpha-synuclein oligomers and their implications.
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Affiliation(s)
- Nora Bengoa-Vergniory
- Department of Physiology, Anatomy and Genetics, Oxford Parkinson's Disease Centre, University of Oxford, South Parks Road, Oxford, OX1 3QT, UK
| | - Rosalind F Roberts
- Montreal Neurological Institute, McGill University, 3801 Rue University, Montreal, QC, H3A 2B4, Canada
| | - Richard Wade-Martins
- Department of Physiology, Anatomy and Genetics, Oxford Parkinson's Disease Centre, University of Oxford, South Parks Road, Oxford, OX1 3QT, UK.
| | - Javier Alegre-Abarrategui
- Department of Physiology, Anatomy and Genetics, Oxford Parkinson's Disease Centre, University of Oxford, South Parks Road, Oxford, OX1 3QT, UK.
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28
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Diez R, Richardson MJE, Wall MJ. Reducing Extracellular Ca 2+ Induces Adenosine Release via Equilibrative Nucleoside Transporters to Provide Negative Feedback Control of Activity in the Hippocampus. Front Neural Circuits 2017; 11:75. [PMID: 29066955 PMCID: PMC5641293 DOI: 10.3389/fncir.2017.00075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/27/2017] [Indexed: 12/04/2022] Open
Abstract
Neural circuit activity increases the release of the purine neuromodulator adenosine into the extracellular space leading to A1 receptor activation and negative feedback via membrane hyperpolarization and inhibition of transmitter release. Adenosine can be released by a number of different mechanisms that include Ca2+ dependent processes such as the exocytosis of ATP. During sustained pathological network activity, ischemia and hypoxia the extracellular concentration of calcium ions (Ca2+) markedly falls, inhibiting exocytosis and potentially reducing adenosine release. However it has been observed that reducing extracellular Ca2+ can induce paradoxical neural activity and can also increase adenosine release. Here we have investigated adenosine signaling and release mechanisms that occur when extracellular Ca2+ is removed. Using electrophysiology and microelectrode biosensor measurements we have found that adenosine is directly released into the extracellular space by the removal of extracellular Ca2+ and controls the induced neural activity via A1 receptor-mediated membrane potential hyperpolarization. Following Ca2+ removal, adenosine is released via equilibrative nucleoside transporters (ENTs), which when blocked leads to hyper-excitation. We propose that sustained action potential firing following Ca2+ removal leads to hydrolysis of ATP and a build-up of intracellular adenosine which then effluxes into the extracellular space via ENTs.
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Affiliation(s)
- Rebecca Diez
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | | | - Mark J Wall
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
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29
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Walker DG, Lue LF, Tang TM, Adler CH, Caviness JN, Sabbagh MN, Serrano GE, Sue LI, Beach TG. Changes in CD200 and intercellular adhesion molecule-1 (ICAM-1) levels in brains of Lewy body disorder cases are associated with amounts of Alzheimer's pathology not α-synuclein pathology. Neurobiol Aging 2017; 54:175-186. [PMID: 28390825 DOI: 10.1016/j.neurobiolaging.2017.03.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/30/2017] [Accepted: 03/07/2017] [Indexed: 12/21/2022]
Abstract
Enhanced inflammation has been associated with Alzheimer's disease (AD) and diseases with Lewy body (LB) pathology, such as Parkinson's disease (PD) and dementia with Lewy bodies (DLB). One issue is whether amyloid and tangle pathology, features of AD, or α-synuclein LB pathology have similar or different effects on brain inflammation. An aim of this study was to examine if certain features of inflammation changed in brains with increasing LB pathology. To assess this, we measured levels of the anti-inflammatory protein CD200 and the pro-inflammatory protein intercellular adhesion molecule-1 (ICAM-1) in cingulate and temporal cortex from a total of 143 cases classified according to the Unified Staging System for LB disorders. Changes in CD200 and ICAM-1 levels did not correlate with LB pathology, but with AD pathology. CD200 negatively correlated with density of neurofibrillary tangles, phosphorylated tau, and amyloid plaque density. ICAM-1 positively correlated with these AD pathology measures. Double immunohistochemistry for phosphorylated α-synuclein and markers for microglia showed limited association of microglia with LB pathology, but microglia strongly associated with amyloid plaques or phosphorylated tau. These results suggest that there are different features of inflammatory pathology in diseases associated with abnormal α-synuclein compared with AD.
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Affiliation(s)
- Douglas G Walker
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ, USA; Banner Sun Health Research Institute, Sun City, AZ, USA.
| | - Lih-Fen Lue
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ, USA; Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Tiffany M Tang
- Neurodegenerative Disease Research Center, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Charles H Adler
- Department of Neurology, Mayo Clinic College of Medicine, Scottsdale, AZ, USA
| | - John N Caviness
- Department of Neurology, Mayo Clinic College of Medicine, Scottsdale, AZ, USA
| | | | | | - Lucia I Sue
- Banner Sun Health Research Institute, Sun City, AZ, USA
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30
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The Contribution of α-Synuclein Spreading to Parkinson's Disease Synaptopathy. Neural Plast 2017; 2017:5012129. [PMID: 28133550 PMCID: PMC5241463 DOI: 10.1155/2017/5012129] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 11/11/2016] [Accepted: 11/22/2016] [Indexed: 12/11/2022] Open
Abstract
Synaptopathies are diseases with synapse defects as shared pathogenic features, encompassing neurodegenerative disorders such as Parkinson's disease (PD). In sporadic PD, the most common age-related neurodegenerative movement disorder, nigrostriatal dopaminergic deficits are responsible for the onset of motor symptoms that have been related to α-synuclein deposition at synaptic sites. Indeed, α-synuclein accumulation can impair synaptic dopamine release and induces the death of nigrostriatal neurons. While in physiological conditions the protein can interact with and modulate synaptic vesicle proteins and membranes, numerous experimental evidences have confirmed that its pathological aggregation can compromise correct neuronal functioning. In addition, recent findings indicate that α-synuclein pathology spreads into the brain and can affect the peripheral autonomic and somatic nervous system. Indeed, monomeric, oligomeric, and fibrillary α-synuclein can move from cell to cell and can trigger the aggregation of the endogenous protein in recipient neurons. This novel “prion-like” behavior could further contribute to synaptic failure in PD and other synucleinopathies. This review describes the major findings supporting the occurrence of α-synuclein pathology propagation in PD and discusses how this phenomenon could induce or contribute to synaptic injury and degeneration.
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31
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van Diggelen F, Tepper AWJW, Apetri MM, Otzen DE. α-Synuclein Oligomers: A Study in Diversity. Isr J Chem 2016. [DOI: 10.1002/ijch.201600116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Femke van Diggelen
- Crossbeta Biosciences; Padualaan 8 3584CH Utrecht The Netherlands
- Interdisciplinary Nanoscience Centre (iNANO); Aarhus University; Gustav Wieds Vej 14 8000C Aarhus Denmark
| | | | | | - Daniel E. Otzen
- Interdisciplinary Nanoscience Centre (iNANO); Aarhus University; Gustav Wieds Vej 14 8000C Aarhus Denmark
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32
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Ingelsson M. Alpha-Synuclein Oligomers-Neurotoxic Molecules in Parkinson's Disease and Other Lewy Body Disorders. Front Neurosci 2016; 10:408. [PMID: 27656123 PMCID: PMC5011129 DOI: 10.3389/fnins.2016.00408] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/23/2016] [Indexed: 12/15/2022] Open
Abstract
Adverse intra- and extracellular effects of toxic α-synuclein are believed to be central to the pathogenesis in Parkinson's disease and other disorders with Lewy body pathology in the nervous system. One of the physiological roles of α-synuclein relates to the regulation of neurotransmitter release at the presynapse, although it is still unclear whether this mechanism depends on the action of monomers or smaller oligomers. As for the pathogenicity, accumulating evidence suggest that prefibrillar species, rather than the deposits per se, are responsible for the toxicity in affected cells. In particular, larger oligomers or protofibrils of α-synuclein have been shown to impair protein degradation as well as the function of several organelles, such as the mitochondria and the endoplasmic reticulum. Accumulating evidence further suggest that oligomers/protofibrils may have a toxic effect on the synapse, which may lead to disrupted electrophysiological properties. In addition, recent data indicate that oligomeric α-synuclein species can spread between cells, either as free-floating proteins or via extracellular vesicles, and thereby act as seeds to propagate disease between interconnected brain regions. Taken together, several lines of evidence suggest that α-synuclein have neurotoxic properties and therefore should be an appropriate molecular target for therapeutic intervention in Parkinson's disease and other disorders with Lewy pathology. In this context, immunotherapy with monoclonal antibodies against α-synuclein oligomers/protofibrils should be a particularly attractive treatment option.
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Affiliation(s)
- Martin Ingelsson
- Rudbeck Laboratory, Department of Public Health/Geriatrics, Uppsala University Uppsala, Sweden
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