1
|
Auf der Heiden F, Axer M, Amunts K, Menzel M. Scattering polarimetry enables correlative nerve fiber imaging and multimodal analysis. Sci Rep 2025; 15:18493. [PMID: 40425688 DOI: 10.1038/s41598-025-02762-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2025] [Accepted: 05/15/2025] [Indexed: 05/29/2025] Open
Abstract
Mapping the intricate network of nerve fibers is crucial for understanding brain function. Three-Dimensional Polarized Light Imaging (3D-PLI) and Computational Scattered Light Imaging (ComSLI) map dense nerve fibers in brain sections with micrometer resolution using visible light. 3D-PLI reconstructs 3D-fiber orientations, while ComSLI disentangles multiple directions per pixel. So far, these imaging techniques have been realized in separate setups. A combination within a single device would facilitate faster measurements, pixelwise mapping, cross-validation of fiber orientations, and leverage the advantages of each technique while mitigating their limitations. Here, we introduce the Scattering Polarimeter, a microscope that facilitates correlative large-area scans by integrating 3D-PLI and ComSLI measurements into a single system. Based on a Mueller polarimeter, it incorporates variable retarders and a large-area light source for direct and oblique illumination, enabling combined 3D-PLI and ComSLI measurements. Applied to human and vervet monkey brain sections, the Scattering Polarimeter generates results comparable to state-of-the-art 3D-PLI and ComSLI setups and creates a multimodal fiber direction map, integrating the robust fiber orientations obtained from 3D-PLI with fiber crossings from ComSLI. Furthermore, we discuss applications of the Scattering Polarimeter for unprecedented correlative and multimodal brain imaging.
Collapse
Affiliation(s)
- Franca Auf der Heiden
- Institute of Neuroscience and Medicine (INM-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany
| | - Markus Axer
- Institute of Neuroscience and Medicine (INM-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany.
- Department of Physics, School of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, 42119, Germany.
| | - Katrin Amunts
- Institute of Neuroscience and Medicine (INM-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany
- C. and O. Vogt Institute for Brain Research, University Hospital Düsseldorf, Düsseldorf, 40225, Germany
| | - Miriam Menzel
- Institute of Neuroscience and Medicine (INM-1), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany.
- Department of Imaging Physics, Delft University of Technology, Delft, 2628 CJ, The Netherlands.
| |
Collapse
|
2
|
Maass F, Canaslan S, van Riesen C, Hermann P, Schmitz M, Schulte C, Brockmann K, Synofzik M, Bähr M, Zerr I. Myelin basic protein and TREM2 quantification in the CSF of patients with Multiple System Atrophy and other Parkinsonian conditions. J Neurol 2024; 272:52. [PMID: 39666067 PMCID: PMC11638341 DOI: 10.1007/s00415-024-12747-w] [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: 10/07/2024] [Revised: 11/05/2024] [Accepted: 11/06/2024] [Indexed: 12/13/2024]
Abstract
BACKGROUND It is well known that myelin disruption and neuroinflammation are early and distinct pathological hallmarks in multiple system atrophy (MSA) as well as in idiopathic Parkinson's disease and in other atypical Parkinsonian syndromes. The objective of this study was to assess the value of non-neuronal biomarker candidates that reflect myelin disruption and neuroinflammation. METHODS Myelin basic protein (MBP) and the soluble form of TREM2 were quantified in a comprehensive movement disorder cohort from two different neurological centers, comprising a total of 171 CSF samples. Commercially available ELISA systems were employed for quantification. RESULTS The results of the MBP analysis revealed a significant increase in cerebrospinal fluid (CSF) MBP levels in all atypical Parkinsonian conditions compared to PD. This differentiation was more pronounced in the MSA-c subtype compared to MSA-p. Receiver operating characteristic (ROC) analysis revealed a significant discrimination between PD and MSA (p = 0.032, AUC = 0.70), PD and DLB (p = 0.006, AUC = 0.79) and PD and tauopathies (p = 0.006, AUC = 0.74). The results of the TREM2 analysis demonstrated no significant differences between the PD and atypical Parkinsonian groups if not adjusted for confounders. After adjusting for age, sex, and disease duration, the PD group exhibited significantly higher TREM2 levels compared to the DLB group (p = 0.002). CONCLUSIONS In conclusion, MBP, but not TREM2, is elevated in the CSF of not only MSA but in all atypical Parkinsonian conditions compared to idiopathic Parkinson's disease. This highlights the value of the evaluation of myelin/oligodendrocyte-associated markers in neurodegenerative movement disorders.
Collapse
Affiliation(s)
- Fabian Maass
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
| | - Sezgi Canaslan
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Christoph van Riesen
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| | - Peter Hermann
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Matthias Schmitz
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Claudia Schulte
- Hertie Institute for Clinical Brain Research and Center of Neurology, Department of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Kathrin Brockmann
- Hertie Institute for Clinical Brain Research and Center of Neurology, Department of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Matthis Synofzik
- Hertie Institute for Clinical Brain Research and Center of Neurology, Department of Neurodegenerative Diseases, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Inga Zerr
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
| |
Collapse
|
3
|
Venati SR, Uversky VN. Exploring Intrinsic Disorder in Human Synucleins and Associated Proteins. Int J Mol Sci 2024; 25:8399. [PMID: 39125972 PMCID: PMC11313516 DOI: 10.3390/ijms25158399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
In this work, we explored the intrinsic disorder status of the three members of the synuclein family of proteins-α-, β-, and γ-synucleins-and showed that although all three human synucleins are highly disordered, the highest levels of disorder are observed in γ-synuclein. Our analysis of the peculiarities of the amino acid sequences and modeled 3D structures of the human synuclein family members revealed that the pathological mutations A30P, E46K, H50Q, A53T, and A53E associated with the early onset of Parkinson's disease caused some increase in the local disorder propensity of human α-synuclein. A comparative sequence-based analysis of the synuclein proteins from various evolutionary distant species and evaluation of their levels of intrinsic disorder using a set of commonly used bioinformatics tools revealed that, irrespective of their origin, all members of the synuclein family analyzed in this study were predicted to be highly disordered proteins, indicating that their intrinsically disordered nature represents an evolutionary conserved and therefore functionally important feature. A detailed functional disorder analysis of the proteins in the interactomes of the human synuclein family members utilizing a set of commonly used disorder analysis tools showed that the human α-synuclein interactome has relatively higher levels of intrinsic disorder as compared with the interactomes of human β- and γ- synucleins and revealed that, relative to the β- and γ-synuclein interactomes, α-synuclein interactors are involved in a much broader spectrum of highly diversified functional pathways. Although proteins interacting with three human synucleins were characterized by highly diversified functionalities, this analysis also revealed that the interactors of three human synucleins were involved in three common functional pathways, such as the synaptic vesicle cycle, serotonergic synapse, and retrograde endocannabinoid signaling. Taken together, these observations highlight the critical importance of the intrinsic disorder of human synucleins and their interactors in various neuronal processes.
Collapse
Affiliation(s)
- Sriya Reddy Venati
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA;
| | - Vladimir N. Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA;
- USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| |
Collapse
|
4
|
Staerz SD, Anamoah C, Tepe JJ. 20S proteasome enhancers prevent cytotoxic tubulin polymerization-promoting protein induced α-synuclein aggregation. iScience 2024; 27:110166. [PMID: 38974969 PMCID: PMC11225362 DOI: 10.1016/j.isci.2024.110166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/05/2024] [Accepted: 05/30/2024] [Indexed: 07/09/2024] Open
Abstract
Synucleinopathies are a class of neurodegenerative diseases defined by the presence of α-synuclein inclusions. The location and composition of these α-synuclein inclusions directly correlate to the disease pattern. The inclusions in Multiple System Atrophy are located predominantly in oligodendrocytes and are rich in a second protein, p25α. P25α plays a key role in neuronal myelination by oligodendrocytes. In healthy oligodendrocytes, there is little to no α-synuclein present. If aberrant α-synuclein is present, p25α leaves the myelin sheaths and quickly co-aggregates with α-synuclein, resulting in the disruption of the cellular process and ultimately cell death. Herein, we report that p25α is susceptible for 20S proteasome-mediated degradation and that p25α induces α-synuclein aggregation, resulting in proteasome impairment and cell death. In addition, we identified small molecules 20S proteasome enhancers that prevent p25α induced α-synuclein fibrilization, restore proteasome impairment, and enhance cell viability.
Collapse
Affiliation(s)
- Sophia D. Staerz
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Charles Anamoah
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
| | - Jetze J. Tepe
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| |
Collapse
|
5
|
Yi S, Wang L, Wang H, Ho MS, Zhang S. Pathogenesis of α-Synuclein in Parkinson's Disease: From a Neuron-Glia Crosstalk Perspective. Int J Mol Sci 2022; 23:14753. [PMID: 36499080 PMCID: PMC9739123 DOI: 10.3390/ijms232314753] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder. The classical behavioral defects of PD patients involve motor symptoms such as bradykinesia, tremor, and rigidity, as well as non-motor symptoms such as anosmia, depression, and cognitive impairment. Pathologically, the progressive loss of dopaminergic (DA) neurons in the substantia nigra (SN) and the accumulation of α-synuclein (α-syn)-composed Lewy bodies (LBs) and Lewy neurites (LNs) are key hallmarks. Glia are more than mere bystanders that simply support neurons, they actively contribute to almost every aspect of neuronal development and function; glial dysregulation has been implicated in a series of neurodegenerative diseases including PD. Importantly, amounting evidence has added glial activation and neuroinflammation as new features of PD onset and progression. Thus, gaining a better understanding of glia, especially neuron-glia crosstalk, will not only provide insight into brain physiology events but also advance our knowledge of PD pathologies. This review addresses the current understanding of α-syn pathogenesis in PD, with a focus on neuron-glia crosstalk. Particularly, the transmission of α-syn between neurons and glia, α-syn-induced glial activation, and feedbacks of glial activation on DA neuron degeneration are thoroughly discussed. In addition, α-syn aggregation, iron deposition, and glial activation in regulating DA neuron ferroptosis in PD are covered. Lastly, we summarize the preclinical and clinical therapies, especially targeting glia, in PD treatments.
Collapse
Affiliation(s)
| | | | | | - Margaret S. Ho
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shiping Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| |
Collapse
|
6
|
Sadler GL, Lewis KN, Narayana VK, De Souza DP, Mason J, McLean C, Gonsalvez DG, Turner BJ, Barton SK. Lipid Metabolism Is Dysregulated in the Motor Cortex White Matter in Amyotrophic Lateral Sclerosis. Metabolites 2022; 12:metabo12060554. [PMID: 35736487 PMCID: PMC9230865 DOI: 10.3390/metabo12060554] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
Lipid metabolism is profoundly dysregulated in amyotrophic lateral sclerosis (ALS), yet the lipid composition of the white matter, where the myelinated axons of motor neurons are located, remains uncharacterised. We aimed to comprehensively characterise how myelin is altered in ALS by assessing its lipid and protein composition. We isolated white matter from the motor cortex from post-mortem tissue of ALS patients (n = 8 sporadic ALS cases and n = 6 familial ALS cases) and age- and sex-matched controls (n = 8) and conducted targeted lipidomic analyses, qPCR for gene expression of relevant lipid metabolising enzymes and Western blotting for myelin proteins. We also quantified myelin density by using spectral confocal reflectance microscopy (SCoRe). Whilst myelin protein composition was similar in ALS and control tissue, both the lipid levels and the expression of their corresponding enzymes were dysregulated, highlighting altered lipid metabolism in the white matter as well as a likely change in myelin composition. Altered myelin composition could contribute to motor neuron dysfunction, and this highlights how oligodendrocytes may play a critical role in ALS pathogenesis.
Collapse
Affiliation(s)
- Gemma L. Sadler
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; (G.L.S.); (K.N.L.); (J.M.); (B.J.T.)
| | - Katherine N. Lewis
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; (G.L.S.); (K.N.L.); (J.M.); (B.J.T.)
| | - Vinod K. Narayana
- Metabolomics Australia, Bio21 Institute, University of Melbourne, Melbourne 3052, Australia; (V.K.N.); (D.P.D.S.)
| | - David P. De Souza
- Metabolomics Australia, Bio21 Institute, University of Melbourne, Melbourne 3052, Australia; (V.K.N.); (D.P.D.S.)
| | - Joel Mason
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; (G.L.S.); (K.N.L.); (J.M.); (B.J.T.)
| | - Catriona McLean
- Victorian Brain Bank, Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia;
| | - David G. Gonsalvez
- Department of Anatomy and Developmental Biology, Monash University, Melbourne 3168, Australia;
| | - Bradley J. Turner
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; (G.L.S.); (K.N.L.); (J.M.); (B.J.T.)
| | - Samantha K. Barton
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; (G.L.S.); (K.N.L.); (J.M.); (B.J.T.)
- Correspondence:
| |
Collapse
|
7
|
Cheng A, Wang YF, Shinoda Y, Kawahata I, Yamamoto T, Jia WB, Yamamoto H, Mizobata T, Kawata Y, Fukunaga K. Fatty acid-binding protein 7 triggers α-synuclein oligomerization in glial cells and oligodendrocytes associated with oxidative stress. Acta Pharmacol Sin 2022; 43:552-562. [PMID: 33935286 PMCID: PMC8888578 DOI: 10.1038/s41401-021-00675-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/31/2021] [Indexed: 02/03/2023]
Abstract
We previously show that fatty acid-binding protein 3 (FABP3) triggers α-synuclein (Syn) accumulation and induces dopamine neuronal cell death in Parkinson disease mouse model. But the role of fatty acid-binding protein 7 (FABP7) in the brain remains unclear. In this study we investigated whether FABP7 was involved in synucleinopathies. We showed that FABP7 was co-localized and formed a complex with Syn in Syn-transfected U251 human glioblastoma cells, and treatment with arachidonic acid (100 M) significantly promoted FABP7-induced Syn aggregation, which was associated with cell death. We demonstrated that synthetic FABP7 ligand 6 displayed a high affinity against FABP7 with Kd value of 209 nM assessed in 8-anilinonaphthalene-1-sulfonic acid (ANS) assay; ligand 6 improved U251 cell survival via disrupting the FABP7-Syn interaction. We showed that activation of phospholipase A2 (PLA2) by psychosine (10 M) triggered oligomerization of endogenous Syn and FABP7, and induced cell death in both KG-1C human oligodendroglia cells and oligodendrocyte precursor cells (OPCs). FABP7 ligand 6 (1 M) significantly decreased Syn oligomerization and aggregation thereby prevented KG-1C and OPC cell death. This study demonstrates that FABP7 triggers α-synuclein oligomerization through oxidative stress, while FABP7 ligand 6 can inhibit FABP7-induced Syn oligomerization and aggregation, thereby rescuing glial cells and oligodendrocytes from cell death.
Collapse
Affiliation(s)
- An Cheng
- grid.69566.3a0000 0001 2248 6943Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yi-fei Wang
- grid.69566.3a0000 0001 2248 6943Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yasuharu Shinoda
- grid.69566.3a0000 0001 2248 6943Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Ichiro Kawahata
- grid.69566.3a0000 0001 2248 6943Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Tetsunori Yamamoto
- grid.69566.3a0000 0001 2248 6943Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Wen-bin Jia
- grid.69566.3a0000 0001 2248 6943Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Hanae Yamamoto
- grid.265107.70000 0001 0663 5064Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Tomohiro Mizobata
- grid.265107.70000 0001 0663 5064Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Yasushi Kawata
- grid.265107.70000 0001 0663 5064Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
| |
Collapse
|
8
|
Liu Y, Castano D, Girolamo F, Trigueros-Motos L, Bae HG, Neo SP, Oh J, Narayanaswamy P, Torta F, Rye KA, Jo DG, Gunaratne J, Jung S, Virgintino D, Singaraja RR. Loss of ABCA8B decreases myelination by reducing oligodendrocyte precursor cells in mice. J Lipid Res 2022; 63:100147. [PMID: 34752805 PMCID: PMC8953628 DOI: 10.1016/j.jlr.2021.100147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/31/2021] [Accepted: 11/01/2021] [Indexed: 01/29/2023] Open
Abstract
The myelin sheath, which is wrapped around axons, is a lipid-enriched structure produced by mature oligodendrocytes. Disruption of the myelin sheath is observed in several neurological diseases, such as multiple sclerosis. A crucial component of myelin is sphingomyelin, levels of which can be increased by ABCA8, a member of the ATP-binding cassette transporter family. ABCA8 is highly expressed in the cerebellum, specifically in oligodendroglia. However, whether ABCA8 plays a role in myelination and mechanisms that would underlie this role remain unknown. Here, we found that the absence of Abca8b, a mouse ortholog of ABCA8, led to decreased numbers of cerebellar oligodendrocyte precursor cells (OPCs) and mature oligodendrocytes in mice. We show that in oligodendrocytes, ABCA8 interacts with chondroitin sulfate proteoglycan 4 (CSPG4), a molecule essential for OPC proliferation, migration, and myelination. In the absence of Abca8b, localization of CSPG4 to the plasma membrane was decreased, contributing to reduced cerebellar CSPG4 expression. Cerebellar CSPG4+ OPCs were also diminished, leading to decreased mature myelinating oligodendrocyte numbers and cerebellar myelination levels in Abca8b-/- mice. In addition, electron microscopy analyses showed that the number of nonmyelinated cerebellar axons was increased, whereas cerebellar myelin thickness (g-ratio), myelin sheath periodicity, and axonal diameter were all decreased, indicative of disordered myelin ultrastructure. In line with disrupted cerebellar myelination, Abca8b-/- mice showed lower cerebellar conduction velocity and disturbed locomotion. In summary, ABCA8 modulates cerebellar myelination, in part through functional regulation of the ABCA8-interacting protein CSPG4. Our findings suggest that ABCA8 disruption may contribute to the pathophysiology of myelin disorders.
Collapse
Affiliation(s)
- Yiran Liu
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Cardiovascular Research Institute, National University Health System, Singapore, Singapore
| | - David Castano
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Cardiovascular Research Institute, National University Health System, Singapore, Singapore
| | - Francesco Girolamo
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy
| | - Laia Trigueros-Motos
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore
| | - Han-Gyu Bae
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
| | - Suat Peng Neo
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | - Jeongah Oh
- Singapore Lipidomics Incubator, Department of Biochemistry, Life Sciences Institute and Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Pradeep Narayanaswamy
- Singapore Lipidomics Incubator, Department of Biochemistry, Life Sciences Institute and Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Federico Torta
- Singapore Lipidomics Incubator, Department of Biochemistry, Life Sciences Institute and Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Kerry Anne Rye
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Jayantha Gunaratne
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | - Sangyong Jung
- Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore
| | - Daniela Virgintino
- Department of Basic Medical Sciences, Neurosciences, and Sensory Organs, Human Anatomy and Histology Unit, University of Bari School of Medicine, Bari, Italy
| | - Roshni R Singaraja
- Translational Laboratories in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Cardiovascular Research Institute, National University Health System, Singapore, Singapore.
| |
Collapse
|
9
|
Marques TM, van Rumund A, Kersten I, Bruinsma IB, Wessels HJ, Gloerich J, Kaffa C, Esselink RAJ, Bloem BR, Kuiperij HB, Verbeek MM. Identification of cerebrospinal fluid biomarkers for parkinsonism using a proteomics approach. NPJ Parkinsons Dis 2021; 7:107. [PMID: 34848724 PMCID: PMC8633286 DOI: 10.1038/s41531-021-00249-9] [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: 02/19/2021] [Accepted: 10/27/2021] [Indexed: 01/25/2023] Open
Abstract
The aim of our study was to investigate cerebrospinal fluid (CSF) tryptic peptide profiles as potential diagnostic biomarkers for the discrimination of parkinsonian disorders. CSF samples were collected from individuals with parkinsonism, who had an uncertain diagnosis at the time of inclusion and who were followed for up to 12 years in a longitudinal study. We performed shotgun proteomics to identify tryptic peptides in CSF of Parkinson's disease (PD, n = 10), multiple system atrophy patients (MSA, n = 5) and non-neurological controls (n = 10). We validated tryptic peptides with differential levels between PD and MSA using a newly developed selected reaction monitoring (SRM) assay in CSF of PD (n = 46), atypical parkinsonism patients (AP; MSA, n = 17; Progressive supranuclear palsy; n = 8) and non-neurological controls (n = 39). We identified 191 tryptic peptides that differed significantly between PD and MSA, of which 34 met our criteria for SRM development. For 14/34 peptides we confirmed differences between PD and AP. These tryptic peptides discriminated PD from AP with moderate-to-high accuracy. Random forest modelling including tryptic peptides plus either clinical assessments or other CSF parameters (neurofilament light chain, phosphorylated tau protein) and age improved the discrimination of PD vs. AP. Our results show that the discovery of tryptic peptides by untargeted and subsequent validation by targeted proteomics is a suitable strategy to identify potential CSF biomarkers for PD versus AP. Furthermore, the tryptic peptides, and corresponding proteins, that we identified as differential biomarkers may increase our current knowledge about the disease-specific pathophysiological mechanisms of parkinsonism.
Collapse
Affiliation(s)
- Tainá M. Marques
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,Radboudumc Center of Expertise for Parkinson & Movement Disorders, Nijmegen, The Netherlands ,grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anouke van Rumund
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,Radboudumc Center of Expertise for Parkinson & Movement Disorders, Nijmegen, The Netherlands
| | - Iris Kersten
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ilona B. Bruinsma
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hans J.C.T. Wessels
- grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jolein Gloerich
- grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Charlotte Kaffa
- grid.10417.330000 0004 0444 9382Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rianne A. J. Esselink
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,Radboudumc Center of Expertise for Parkinson & Movement Disorders, Nijmegen, The Netherlands
| | - Bastiaan R. Bloem
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,Radboudumc Center of Expertise for Parkinson & Movement Disorders, Nijmegen, The Netherlands
| | - H. Bea Kuiperij
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marcel M. Verbeek
- grid.10417.330000 0004 0444 9382Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands ,Radboudumc Center of Expertise for Parkinson & Movement Disorders, Nijmegen, The Netherlands ,grid.10417.330000 0004 0444 9382Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| |
Collapse
|
10
|
Bettencourt C, Miki Y, Piras IS, de Silva R, Foti SC, Talboom JS, Revesz T, Lashley T, Balazs R, Viré E, Warner TT, Huentelman MJ, Holton JL. MOBP and HIP1 in multiple system atrophy: New α-synuclein partners in glial cytoplasmic inclusions implicated in the disease pathogenesis. Neuropathol Appl Neurobiol 2021; 47:640-652. [PMID: 33368549 PMCID: PMC8219819 DOI: 10.1111/nan.12688] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/16/2020] [Accepted: 12/14/2020] [Indexed: 01/02/2023]
Abstract
AIMS Multiple system atrophy (MSA) is a fatal neurodegenerative disease. Similar to Parkinson's disease (PD), MSA is an α-synucleinopathy, and its pathological hallmark consists of glial cytoplasmic inclusions (GCIs) containing α-synuclein (SNCA) in oligodendrocytes. We previously identified consistent changes in myelin-associated oligodendrocyte basic protein (MOBP) and huntingtin interacting protein 1 (HIP1) DNA methylation status in MSA. We hypothesized that if differential DNA methylation at these loci is mechanistically relevant for MSA, it should have downstream consequences on gene regulation. METHODS We investigated the relationship between MOBP and HIP1 DNA methylation and mRNA levels in cerebellar white matter from MSA and healthy controls. Additionally, we analysed protein expression using western blotting, immunohistochemistry and proximity ligation assays. RESULTS We found decreased MOBP mRNA levels significantly correlated with increased DNA methylation in MSA. For HIP1, we found a distinct relationship between DNA methylation and gene expression levels in MSA compared to healthy controls, suggesting this locus may be subjected to epigenetic remodelling in MSA. Although soluble protein levels for MOBP and HIP1 in cerebellar white matter were not significantly different between MSA cases and controls, we found striking differences between MSA and other neurodegenerative diseases, including PD and Huntington's disease. We also found that MOBP and HIP1 are mislocalized into the GCIs in MSA, where they appear to interact with SNCA. CONCLUSIONS This study supports a role for DNA methylation in downregulation of MOBP mRNA in MSA. Most importantly, the identification of MOBP and HIP1 as new constituents of GCIs emphasizes the relevance of these two loci to the pathogenesis of MSA.
Collapse
Affiliation(s)
- Conceição Bettencourt
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of NeurologyLondonUK
| | - Yasuo Miki
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of NeuropathologyInstitute of Brain ScienceHirosaki University Graduate School of MedicineHirosakiJapan
| | - Ignazio S. Piras
- Neurogenomics DivisionTranslational Genomics Research InstitutePhoenixAZUSA
| | - Rohan de Silva
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of NeurologyLondonUK
- Reta Lila Weston InstituteUCL Queen Square Institute of NeurologyLondonUK
| | - Sandrine C. Foti
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of Neurodegenerative DiseaseUCL Queen Square Institute of NeurologyLondonUK
| | - Joshua S. Talboom
- Neurogenomics DivisionTranslational Genomics Research InstitutePhoenixAZUSA
| | - Tamas Revesz
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Reta Lila Weston InstituteUCL Queen Square Institute of NeurologyLondonUK
- Department of Neurodegenerative DiseaseUCL Queen Square Institute of NeurologyLondonUK
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of Neurodegenerative DiseaseUCL Queen Square Institute of NeurologyLondonUK
| | - Robert Balazs
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of Neurodegenerative DiseaseUCL Queen Square Institute of NeurologyLondonUK
| | | | - Thomas T. Warner
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of NeurologyLondonUK
- Reta Lila Weston InstituteUCL Queen Square Institute of NeurologyLondonUK
| | - Matt J. Huentelman
- Neurogenomics DivisionTranslational Genomics Research InstitutePhoenixAZUSA
| | - Janice L. Holton
- Queen Square Brain Bank for Neurological DisordersUCL Queen Square Institute of NeurologyLondonUK
- Department of Clinical and Movement NeurosciencesUCL Queen Square Institute of NeurologyLondonUK
| |
Collapse
|
11
|
Srivastava A, Kumar K, Banerjee J, Tripathi M, Dubey V, Sharma D, Yadav N, Sharma MC, Lalwani S, Doddamani R, Chandra PS, Dixit AB. Transcriptomic profiling of high- and low-spiking regions reveals novel epileptogenic mechanisms in focal cortical dysplasia type II patients. Mol Brain 2021; 14:120. [PMID: 34301297 PMCID: PMC8305866 DOI: 10.1186/s13041-021-00832-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 07/14/2021] [Indexed: 11/15/2022] Open
Abstract
Focal cortical dysplasia (FCD) is a malformation of the cerebral cortex with poorly-defined epileptogenic zones (EZs), and poor surgical outcome in FCD is associated with inaccurate localization of the EZ. Hence, identifying novel epileptogenic markers to aid in the localization of EZ in patients with FCD is very much needed. High-throughput gene expression studies of FCD samples have the potential to uncover molecular changes underlying the epileptogenic process and identify novel markers for delineating the EZ. For this purpose, we, for the first time performed RNA sequencing of surgically resected paired tissue samples obtained from electrocorticographically graded high (MAX) and low spiking (MIN) regions of FCD type II patients and autopsy controls. We identified significant changes in the MAX samples of the FCD type II patients when compared to non-epileptic controls, but not in the case of MIN samples. We found significant enrichment for myelination, oligodendrocyte development and differentiation, neuronal and axon ensheathment, phospholipid metabolism, cell adhesion and cytoskeleton, semaphorins, and ion channels in the MAX region. Through the integration of both MAX vs non-epileptic control and MAX vs MIN RNA sequencing (RNA Seq) data, PLP1, PLLP, UGT8, KLK6, SOX10, MOG, MAG, MOBP, ANLN, ERMN, SPP1, CLDN11, TNC, GPR37, SLC12A2, ABCA2, ABCA8, ASPA, P2RX7, CERS2, MAP4K4, TF, CTGF, Semaphorins, Opalin, FGFs, CALB2, and TNC were identified as potential key regulators of multiple pathways related to FCD type II pathology. We have identified novel epileptogenic marker elements that may contribute to epileptogenicity in patients with FCD and could be possible markers for the localization of EZ.
Collapse
Affiliation(s)
| | - Krishan Kumar
- Dr B R Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
| | | | | | - Vivek Dubey
- Department of Biophysics, AIIMS, New Delhi, India
| | - Devina Sharma
- Department of Neurosurgery, AIIMS, New Delhi, 110029, India
| | - Nitin Yadav
- Dr B R Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
| | - M C Sharma
- Department of Pathology, AIIMS, New Delhi, India
| | - Sanjeev Lalwani
- Department of Forensic Medicine and Toxicology, AIIMS, New Delhi, India
| | | | - P Sarat Chandra
- Department of Neurosurgery, AIIMS, New Delhi, 110029, India.
| | - Aparna Banerjee Dixit
- Dr B R Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India.
| |
Collapse
|
12
|
Mavroeidi P, Xilouri M. Neurons and Glia Interplay in α-Synucleinopathies. Int J Mol Sci 2021; 22:4994. [PMID: 34066733 PMCID: PMC8125822 DOI: 10.3390/ijms22094994] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 04/29/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022] Open
Abstract
Accumulation of the neuronal presynaptic protein alpha-synuclein within proteinaceous inclusions represents the key histophathological hallmark of a spectrum of neurodegenerative disorders, referred to by the umbrella term a-synucleinopathies. Even though alpha-synuclein is expressed predominantly in neurons, pathological aggregates of the protein are also found in the glial cells of the brain. In Parkinson's disease and dementia with Lewy bodies, alpha-synuclein accumulates mainly in neurons forming the Lewy bodies and Lewy neurites, whereas in multiple system atrophy, the protein aggregates mostly in the glial cytoplasmic inclusions within oligodendrocytes. In addition, astrogliosis and microgliosis are found in the synucleinopathy brains, whereas both astrocytes and microglia internalize alpha-synuclein and contribute to the spread of pathology. The mechanisms underlying the pathological accumulation of alpha-synuclein in glial cells that under physiological conditions express low to non-detectable levels of the protein are an area of intense research. Undoubtedly, the presence of aggregated alpha-synuclein can disrupt glial function in general and can contribute to neurodegeneration through numerous pathways. Herein, we summarize the current knowledge on the role of alpha-synuclein in both neurons and glia, highlighting the contribution of the neuron-glia connectome in the disease initiation and progression, which may represent potential therapeutic target for a-synucleinopathies.
Collapse
Affiliation(s)
| | - Maria Xilouri
- Center of Clinical Research, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, 11527 Athens, Greece;
| |
Collapse
|
13
|
Yoo HS, Chung SJ, Lee YH, Ye BS, Sohn YH, Kwon H, Lee PH. Urate is closely linked to white matter integrity in multiple system atrophy. Ann Clin Transl Neurol 2021; 7:1029-1039. [PMID: 32588990 PMCID: PMC7318089 DOI: 10.1002/acn3.51073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 05/07/2020] [Accepted: 05/11/2020] [Indexed: 12/13/2022] Open
Abstract
Objective We aimed to investigate the association of the serum urate level with cortical thickness and white matter integrity in multiple system atrophy (MSA). Methods We recruited 75 MSA patients and 42 controls who underwent brain MRI and measured serum urate level at baseline. Using cortical thickness and tract‐based spatial statistics analyses, we investigated the correlation between serum urate levels and cortical thickness or diffusion tensor imaging (DTI) measures in controls and MSA patients. Interaction effects were analyzed to find different patterns of correlation according to sex and clinical subtype. We evaluated the relationship between serum urate levels, DTI measures, and total UMSARS score, using path analysis. Results Serum urate levels showed a positive correlation with FA values in the corpus callosum and a negative correlation with MD values in widespread regions including cerebellar, brainstem, and cerebral white matter in patients with MSA. Both sexes showed a negative correlation between serum urate levels and MD values without significant interaction effect. In subgroup analysis according to subtype, patients with cerebellar subtype showed a negative correlation. Serum urate levels did not correlated with cortical thickness. Path analysis showed that MD values in middle and inferior cerebellar peduncle mediated the association between serum urate level and total UMSAR score. Interpretation The present study demonstrated that serum urate levels played a pivotal role in white matter disintegrity and clinical disability in MSA. It would provide an evidence of the role of urate as a potential neuroprotective factor against white matter neurodegeneration in MSA.
Collapse
Affiliation(s)
- Han Soo Yoo
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Seok Jong Chung
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Yang Hyun Lee
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Byoung Seok Ye
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Young H Sohn
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Hunki Kwon
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Phil Hyu Lee
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea.,Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, South Korea
| |
Collapse
|
14
|
Fanning S, Selkoe D, Dettmer U. Vesicle trafficking and lipid metabolism in synucleinopathy. Acta Neuropathol 2021; 141:491-510. [PMID: 32607605 DOI: 10.1007/s00401-020-02177-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 12/12/2022]
Abstract
The neuronal protein α-synuclein (αS) is central to the pathogenesis of Parkinson's disease and other progressive brain diseases such as Lewy body dementia and multiple system atrophy. These diseases, collectively referred to as 'synucleinopathies', have long been considered purely proteinopathies: diseases characterized by the misfolding of a protein into small and large aggregates mainly consisting of that protein (in this case: α-synuclein). However, recent morphological insights into Lewy bodies, the hallmark neuropathology of human synucleinopathies, suggests these lesions are also rich in vesicles and other membranous organelles. Moreover, αS physiology and pathology are both strongly associated with various aspects of intracellular vesicle trafficking and lipid biology. αS physiologically binds to synaptic and other small vesicles, and several functions of αS in regulating vesicle biology have been proposed. Familial PD-linked αS excess and missense mutations have been shown to impair vesicle trafficking and alter lipid homeostasis. On the other hand, vesicle trafficking and lipid-related genes have emerged as Parkinson's risk factors, suggesting a bidirectional relationship. The answer to the question "Does abnormal αS accumulation cause impaired vesicle trafficking and lipid dyshomeostasis or is αS aggregation the consequence of such impairments?" may be "Both". Here, we review current knowledge of the αS-lipid and αS-vesicle trafficking interplay, with a special focus on Parkinson's disease and Lewy body dementia.
Collapse
|
15
|
Vigen TR, Brudek T, Pakkenberg B, Olesen MV. Quantitative Cellular Changes in the Thalamus of Patients with Multiple System Atrophy. Neuroscience 2021; 459:142-152. [PMID: 33577952 DOI: 10.1016/j.neuroscience.2021.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 01/10/2023]
Abstract
The thalamus is a brain region consisting of anatomical and functional connections between various spinal, subcortical, and cortical regions, which has a putative role in the clinical manifestation of Multiple System Atrophy (MSA). Previous stereological studies have reported significant anatomical alterations in diverse brain regions of MSA patients, including the cerebral cortex, basal ganglia and white matter, but no quantitative studies have examined the thalamus. To establish the extent of thalamic involvement, we applied stereological methods to estimate the total number of neurons and glial cells (oligodendrocytes, astrocytes and microglia) as well as the volume in two thalamic sub-regions, the mediodorsal nucleus (MDT) and the anterior principal nucleus (APn), in brains from ten MSA patients and 11 healthy control subjects. Compared to healthy controls, MSA patients had significantly fewer neurons (26%) in the MDT, but not the APn. We also found significantly more astrocytes (32%) and microglia (54%) in the MDT, with no such changes in the APn. Finally, we saw no group differences in the total number of oligodendrocytes. Our findings show a region-specific loss of thalamic neurons that occurs without loss of oligodendrocytes, whereas thalamic microgliosis seems to occur alongside astrogliosis. These pathological changes in the thalamus may contribute to the cognitive impairment seen in most patients with MSA.
Collapse
Affiliation(s)
- Tanya R Vigen
- Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital, Bispebjerg and Frederiksberg Hospital, Denmark
| | - Tomasz Brudek
- Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital, Bispebjerg and Frederiksberg Hospital, Denmark
| | - Bente Pakkenberg
- Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital, Bispebjerg and Frederiksberg Hospital, Denmark; Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| | - Mikkel V Olesen
- Research Laboratory for Stereology and Neuroscience, Copenhagen University Hospital, Bispebjerg and Frederiksberg Hospital, Denmark
| |
Collapse
|
16
|
Del Campo N, Phillips O, Ory‐Magne F, Brefel‐Courbon C, Galitzky M, Thalamas C, Narr KL, Joshi S, Singh MK, Péran P, Pavy‐LeTraon A, Rascol O. Broad white matter impairment in multiple system atrophy. Hum Brain Mapp 2021; 42:357-366. [PMID: 33064319 PMCID: PMC7776008 DOI: 10.1002/hbm.25227] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 07/09/2020] [Accepted: 08/10/2020] [Indexed: 11/11/2022] Open
Abstract
Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by the widespread aberrant accumulation of α-synuclein (α-syn). MSA differs from other synucleinopathies such as Parkinson's disease (PD) in that α-syn accumulates primarily in oligodendrocytes, the only source of white matter myelination in the brain. Previous MSA imaging studies have uncovered focal differences in white matter. Here, we sought to build on this work by taking a global perspective on whole brain white matter. In order to do this, in vivo structural imaging and diffusion magnetic resonance imaging were acquired on 26 MSA patients, 26 healthy controls, and 23 PD patients. A refined whole brain approach encompassing the major fiber tracts and the superficial white matter located at the boundary of the cortical mantle was applied. The primary observation was that MSA but not PD patients had whole brain deep and superficial white matter diffusivity abnormalities (p < .001). In addition, in MSA patients, these abnormalities were associated with motor (Unified MSA Rating Scale, Part II) and cognitive functions (Mini-Mental State Examination). The pervasive whole brain abnormalities we observe suggest that there is widespread white matter damage in MSA patients which mirrors the widespread aggregation of α-syn in oligodendrocytes. Importantly, whole brain white matter abnormalities were associated with clinical symptoms, suggesting that white matter impairment may be more central to MSA than previously thought.
Collapse
Affiliation(s)
- Natalia Del Campo
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Owen Phillips
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
- Division of Child and Adolescent Psychiatry, Department of PsychiatryStanford University School of MedicineStanfordCaliforniaUSA
- BrainKeySan FranciscoCaliforniaUSA
| | - Françoise Ory‐Magne
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Christine Brefel‐Courbon
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Monique Galitzky
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Claire Thalamas
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Katherine L. Narr
- Department of NeurologyAhmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Shantanu Joshi
- Department of NeurologyAhmanson Lovelace Brain Mapping Center, David Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Manpreet K. Singh
- Division of Child and Adolescent Psychiatry, Department of PsychiatryStanford University School of MedicineStanfordCaliforniaUSA
| | - Patrice Péran
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Anne Pavy‐LeTraon
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| | - Olivier Rascol
- CHU de Toulouse, Université de Toulouse‐Toulouse 3, INSERM, UMR1214 Toulouse NeuroImaging Centre “TONIC,” Center of Excellence in Neurodegeneration (CoEN), NeuroToul, Centre National de Reference AMS, Centre Expert Parkinson de Toulouse, Centre d'Investigation Clinique CIC1436, Services de Neurologie et de Pharmacologie Clinique, UMR 1048 Institute for Cardiovascular DiseasesToulouseFrance
| |
Collapse
|
17
|
The Interplay of ABC Transporters in Aβ Translocation and Cholesterol Metabolism: Implicating Their Roles in Alzheimer's Disease. Mol Neurobiol 2020; 58:1564-1582. [PMID: 33215389 DOI: 10.1007/s12035-020-02211-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023]
Abstract
The occurrence of Alzheimer's disease (AD) worldwide has been progressively accelerating at an alarming rate, without any successful therapeutic strategy for the disease mitigation. The complexity of AD pathogenesis needs to be targeted with an alternative approach, as provided by the superfamily of ATP-binding cassette (ABC) transporters, which constitutes an extensive range of proteins, capable of transporting molecular entities across biological membranes. These protein moieties have been implicated in AD, based upon their potential in lipid transportation, resulting in maintenance of cholesterol homeostasis. These transporters have been reported to target the primary hallmark of AD pathogenesis, namely, beta-amyloid hypothesis, which is associated with accumulation of beta-amyloid (Aβ) plaques in AD patients. The ABC transporters have been observed to be localized to the capillary endothelial cells of the blood-brain barrier and neural parenchymal cells, where they exhibit different roles, consequently influencing the neuronal expression of Aβ peptides. The review highlights different families of ABC transporters, ABCB1 (P-glycoprotein), ABCA (ABCA1, ABCA2, and ABCA7), ABCG2 (BCRP; breast cancer resistance protein), ABCG1 and ABCG4, as well as ABCC1 (MRP; multidrug resistance protein) in the CNS, and their interplay in regulating cholesterol metabolism and Aβ peptide load in the brain, simultaneously exerting protective effects against neurotoxic substrates and xenobiotics. The authors aim to establish the significance of this alternative approach as a novel therapeutic target in AD, to provide the researchers an opportunity to evaluate the potential aspects of ABC transporters in AD treatment.
Collapse
|
18
|
Shenzhiling Oral Liquid Protects STZ-Injured Oligodendrocyte through PI3K/Akt-mTOR Pathway. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:4527283. [PMID: 32774416 PMCID: PMC7396001 DOI: 10.1155/2020/4527283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 06/26/2020] [Accepted: 07/03/2020] [Indexed: 02/01/2023]
Abstract
White matter degeneration and demyelination are nonnegligible pathological manifestations of Alzheimer's disease (AD). The damage of myelin sheath consisting of oligodendrocytes is the basis of AD's unique early lesions. Shenzhiling oral liquid (SZL) was the effective Chinese herbal compound approved by the Food and Drug Administration (FDA) for the treatment of AD in China, which plays the exact therapeutic role in clinical AD patients. However, its molecular mechanism remains unclear to date. For this purpose, an in vitro mode of streptozotocin- (STZ-) induced rat oligodendrocyte OLN-93 cell injury was established to mimic the pathological changes of myelin sheath of AD and investigate the mechanism of SZL protecting injured OLN-93 cell. The results showed that STZ can decrease cell viability and downregulate the activity of PI3K/Akt-mTOR signalling pathway and the expression of myelin sheath-related proteins (MBP, MOG, and PLP) in OLN-93 cells. Both SZL-medicated serum and donepezil (positive control) can protect cells from STZ-caused damage. SZL-medicated serum increased OLN-93 cell viability in a dose- and time-dependent manner and enhanced the activity of PI3K/Akt-mTOR signalling pathway. The inhibitor of PI3K (LY294002) inhibited the protective effect of SZL-medicated serum on the STZ-injured OLN-93 cells. Furthermore, rapamycin, the inhibitor of mTOR, inhibited the promotion of cell viability and upregulation of p-mTOR and MBP caused by SZL-medicated serum. In conclusion, our data indicate that SZL plays its therapeutic role on AD by promoting PI3K/Akt-mTOR signalling pathway of oligodendrocytes. Thus, the present study may facilitate the therapeutic research of AD.
Collapse
|
19
|
Endogenous oligodendroglial alpha-synuclein and TPPP/p25α orchestrate alpha-synuclein pathology in experimental multiple system atrophy models. Acta Neuropathol 2019; 138:415-441. [PMID: 31011860 PMCID: PMC7289399 DOI: 10.1007/s00401-019-02014-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 04/03/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022]
Abstract
Multiple system atrophy (MSA) is characterized by the presence of distinctive glial cytoplasmic inclusions (GCIs) within oligodendrocytes that contain the neuronal protein alpha-synuclein (aSyn) and the oligodendroglia-specific phosphoprotein TPPP/p25α. However, the role of oligodendroglial aSyn and p25α in the formation of aSyn-rich GCIs remains unclear. To address this conundrum, we have applied human aSyn (haSyn) pre-formed fibrils (PFFs) to rat wild-type (WT)-, haSyn-, or p25α-overexpressing oligodendroglial cells and to primary differentiated oligodendrocytes derived from WT, knockout (KO)-aSyn, and PLP-haSyn-transgenic mice. HaSyn PFFs are readily taken up by oligodendroglial cells and can recruit minute amounts of endogenous aSyn into the formation of insoluble, highly aggregated, pathological assemblies. The overexpression of haSyn or p25α accelerates the recruitment of endogenous protein and the generation of such aberrant species. In haSyn PFF-treated primary oligodendrocytes, the microtubule and myelin networks are disrupted, thus recapitulating a pathological hallmark of MSA, in a manner totally dependent upon the seeding of endogenous aSyn. Furthermore, using oligodendroglial and primary cortical cultures, we demonstrated that pathology-related S129 aSyn phosphorylation depends on aSyn and p25α protein load and may involve different aSyn “strains” present in oligodendroglial and neuronal synucleinopathies. Importantly, this hypothesis was further supported by data obtained from human post-mortem brain material derived from patients with MSA and dementia with Lewy bodies. Finally, delivery of haSyn PFFs into the mouse brain led to the formation of aberrant aSyn forms, including the endogenous protein, within oligodendroglia and evoked myelin decompaction in WT mice, but not in KO-aSyn mice. This line of research highlights the role of endogenous aSyn and p25α in the formation of pathological aSyn assemblies in oligodendrocytes and provides in vivo evidence of the contribution of oligodendroglial aSyn in the establishment of aSyn pathology in MSA.
Collapse
|
20
|
Lee MJ, Kim TH, Kim SJ, Mun CW, Shin JH, Lee GH, Lee JH. Speculating the timing of iron deposition in the putamen in multiple system atrophy. Parkinsonism Relat Disord 2019; 63:106-110. [DOI: 10.1016/j.parkreldis.2019.02.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/17/2019] [Accepted: 02/19/2019] [Indexed: 01/26/2023]
|
21
|
Mao XW, Sandberg LB, Gridley DS, Herrmann EC, Zhang G, Raghavan R, Zubarev RA, Zhang B, Stodieck LS, Ferguson VL, Bateman TA, Pecaut MJ. Proteomic Analysis of Mouse Brain Subjected to Spaceflight. Int J Mol Sci 2018; 20:ijms20010007. [PMID: 30577490 PMCID: PMC6337482 DOI: 10.3390/ijms20010007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/11/2018] [Accepted: 12/17/2018] [Indexed: 01/01/2023] Open
Abstract
There is evidence that spaceflight poses acute and late risks to the central nervous system. To explore possible mechanisms, the proteomic changes following spaceflight in mouse brain were characterized. Space Shuttle Atlantis (STS-135) was launched from the Kennedy Space Center (KSC) on a 13-day mission. Within 3–5 h after landing, brain tissue was collected to evaluate protein expression profiles using quantitative proteomic analysis. Our results showed that there were 26 proteins that were significantly altered after spaceflight in the gray and/or white matter. While there was no overlap between the white and gray matter in terms of individual proteins, there was overlap in terms of function, synaptic plasticity, vesical activity, protein/organelle transport, and metabolism. Our data demonstrate that exposure to the spaceflight environment induces significant changes in protein expression related to neuronal structure and metabolic function. This might lead to a significant impact on brain structural and functional integrity that could affect the outcome of space missions.
Collapse
Affiliation(s)
- Xiao Wen Mao
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
| | - Lawrence B Sandberg
- Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Daila S Gridley
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
| | - E Clifford Herrmann
- Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Guangyu Zhang
- Department of Biochemistry, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Ravi Raghavan
- Department of Pathology and Human Anatomy, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Roman A Zubarev
- Department of Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, SE 17177 Stockholm, Sweden.
- Department of Pharmacological and Technological Chemistry, I.M. Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| | - Bo Zhang
- Department of Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, SE 17177 Stockholm, Sweden.
- Department of Pharmacological and Technological Chemistry, I.M. Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| | - Louis S Stodieck
- BioServe Space Technologies, University of Colorado at Boulder, Boulder, CO 80303, USA.
| | - Virginia L Ferguson
- BioServe Space Technologies, University of Colorado at Boulder, Boulder, CO 80303, USA.
| | - Ted A Bateman
- Department of Bioengineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Michael J Pecaut
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
| |
Collapse
|
22
|
Abstract
Multiple system atrophy (MSA) is an orphan, fatal, adult-onset neurodegenerative disorder of uncertain etiology that is clinically characterized by various combinations of parkinsonism, cerebellar, autonomic, and motor dysfunction. MSA is an α-synucleinopathy with specific glioneuronal degeneration involving striatonigral, olivopontocerebellar, and autonomic nervous systems but also other parts of the central and peripheral nervous systems. The major clinical variants correlate with the morphologic phenotypes of striatonigral degeneration (MSA-P) and olivopontocerebellar atrophy (MSA-C). While our knowledge of the molecular pathogenesis of this devastating disease is still incomplete, updated consensus criteria and combined fluid and imaging biomarkers have increased its diagnostic accuracy. The neuropathologic hallmark of this unique proteinopathy is the deposition of aberrant α-synuclein in both glia (mainly oligodendroglia) and neurons forming glial and neuronal cytoplasmic inclusions that cause cell dysfunction and demise. In addition, there is widespread demyelination, the pathogenesis of which is not fully understood. The pathogenesis of MSA is characterized by propagation of misfolded α-synuclein from neurons to oligodendroglia and cell-to-cell spreading in a "prion-like" manner, oxidative stress, proteasomal and mitochondrial dysfunction, dysregulation of myelin lipids, decreased neurotrophic factors, neuroinflammation, and energy failure. The combination of these mechanisms finally results in a system-specific pattern of neurodegeneration and a multisystem involvement that are specific for MSA. Despite several pharmacological approaches in MSA models, addressing these pathogenic mechanisms, no effective neuroprotective nor disease-modifying therapeutic strategies are currently available. Multidisciplinary research to elucidate the genetic and molecular background of the deleterious cycle of noxious processes, to develop reliable biomarkers and targets for effective treatment of this hitherto incurable disorder is urgently needed.
Collapse
|
23
|
Pereira CD, Martins F, Wiltfang J, da Cruz e Silva OA, Rebelo S. ABC Transporters Are Key Players in Alzheimer’s Disease. J Alzheimers Dis 2017; 61:463-485. [DOI: 10.3233/jad-170639] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Cátia D. Pereira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Filipa Martins
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Jens Wiltfang
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen (UMG), Göttingen, Germany
| | - Odete A.B. da Cruz e Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| | - Sandra Rebelo
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, Institute for Biomedicine – iBiMED, University of Aveiro, Aveiro, Portugal
| |
Collapse
|
24
|
Valera E, Masliah E. The neuropathology of multiple system atrophy and its therapeutic implications. Auton Neurosci 2017; 211:1-6. [PMID: 29169744 DOI: 10.1016/j.autneu.2017.11.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 11/06/2017] [Accepted: 11/08/2017] [Indexed: 02/03/2023]
Abstract
Multiple system atrophy (MSA) is a fatal neurodegenerative disorder characterized by the abnormal accumulation of toxic forms of the synaptic protein alpha-synuclein (α-syn) within oligodendrocytes and neurons. The presence of α-syn within oligodendrocytes in the form of glial cytoplasmic inclusions is the diagnostic hallmark of MSA. However, it has been postulated that α-syn is produced in neurons and propagates to oligodendrocytes, where unknown mechanisms lead to its accumulation. The presence of α-syn within neurons in MSA has not been so extensively studied, but it may shed light into neuropathological mechanisms leading to oligodendroglial accumulation. Here we summarize the principal neuropathological events of MSA, and discuss how a deeper knowledge of these mechanisms may help develop effective therapies targeting α-syn accumulation and spreading.
Collapse
Affiliation(s)
- Elvira Valera
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA.
| | - Eliezer Masliah
- Division of Neurosciences, National Institute on Aging/NIH, 7201 Wisconsin Ave, Bethesda, MD 20814, USA.
| |
Collapse
|
25
|
Jellinger KA. Potential clinical utility of multiple system atrophy biomarkers. Expert Rev Neurother 2017; 17:1189-1208. [DOI: 10.1080/14737175.2017.1392239] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
26
|
Abstract
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model remains the most commonly used animal model of Parkinson's disease (PD). There are three MPTP-treatment schemes: acute, subacute and chronic. Considering the advantages of the period and similarity to PD, the subacute model was often chosen to assess the validity of new candidates, but the changes caused by the subacute MPTP treatment and the appropriate positive control for this model remain to be further confirmed. The aim of this study was: to estimate the value of the subacute MPTP mouse model in aspects of behavioral performance, biochemical changes and pathological abnormalities, and to find effective positive drugs. Male C57BL/6 mice were injected with MPTP (30 mg·kg-1·d-1, ip) for 5 consecutive days. Three days before MPTP injection, the mice were orally administered selegiline (3 mg·kg-1·d-1), pramipexole (3 mg·kg-1·d-1), or medopar (100 mg·kg-1·d-1) for 18 days. Behavioral performance was assessed in the open field test, pole test and rotarod test. Neurotransmitters in the striatum were detected using HPLC. Protein levels were measured by Western blot. Pathological characteristics were examined by immunohistochemistry. Ultrastructure changes were observed by electron microscopy. The subacute MPTP treatment did not induce evident motor defects despite severe injuries in the dopaminergic system. Additionally, MPTP significantly increased the α-synuclein levels and the number of astrocytes in the striatum, and destroyed the blood-brain barrier (BBB) in the substantia nigra pars compacta. Both selegiline and pramipexole were able to protect the mice against MPTP injuries. We conclude that the subacute MPTP mouse model does not show visible motor defects; it is not enough to evaluate the validity of a candidate just based on behavioral examination, much attention should also be paid to the alterations in neurotransmitters, astrocytes, α-synuclein and the BBB. In addition, selegiline or pramipexole is a better choice than medopar as an effective positive control for the subacute MPTP model.
Collapse
|
27
|
D'Andrea MR, Howanski RJ, Saller CF. MAP2 IHC detection: a marker of antigenicity in CNS tissues. Biotech Histochem 2017; 92:363-373. [PMID: 28766965 DOI: 10.1080/10520295.2017.1295169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Immunohistochemistry (IHC) is used to detect antibody-specific antigens in tissues; the results depend on the ability of the primary antibodies to bind to their antigens. Therefore, results depend on the quality of preservation of the specimen. Many investigators have overcome the deleterious effects of over-fixation on the binding of primary antibodies to specimen antigens using IHC, but if the specimen is under-fixed or fixation is delayed, false negative results could be obtained despite certified laboratory practices. Microtubule-associated protein 2 (MAP2) is an abundant microtubule-associate protein that participates in the outgrowth of neuronal processes and synaptic plasticity; it is localized primarily in cell bodies and dendrites of neurons. MAP2 immunolabeling has been reported to be absent in areas of the entorhinal cortex and hippocampus of Alzheimer's disease brains that were co-localized with the dense-core type of amyloid plaques. It was hypothesized that the lack of MAP2 immunolabeling in these structures was due to the degradation of the MAP2 antigen by the neuronal proteases that were released as the neurons lysed leading to the formation of these plaques. Because MAP2 is sensitive to proteolysis, we hypothesized that changes in MAP2 immunolabeling may be correlated with the degree of fixation of central nervous system (CNS) tissues. We detected normal MAP2 immunolabeling in fixed rat brain tissues, but MAP2 immunolabeling was decreased or lost in unfixed and delayed-fixed rat brain tissues. By contrast, two ubiquitous CNS-specific markers, myelin basic protein and glial fibrillary acidic protein, were unaffected by the degree of fixation in the same tissues. Our observations suggest that preservation of various CNS-specific antigens differs with the degree of fixation and that the lack of MAP2 immunolabeling in the rat brain may indicate inadequate tissue fixation. We recommend applying MAP2 IHC for all CNS tissues as a pre-screen to assess the quality of the tissue preservation and to avoid potentially false negative IHC results.
Collapse
Affiliation(s)
| | - R J Howanski
- b Analytical Biological Services Inc. , Wilmington , Delaware
| | - C F Saller
- b Analytical Biological Services Inc. , Wilmington , Delaware
| |
Collapse
|
28
|
Grigoletto J, Pukaß K, Gamliel A, Davidi D, Katz-Brull R, Richter-Landsberg C, Sharon R. Higher levels of myelin phospholipids in brains of neuronal α-Synuclein transgenic mice precede myelin loss. Acta Neuropathol Commun 2017; 5:37. [PMID: 28482862 PMCID: PMC5421332 DOI: 10.1186/s40478-017-0439-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 04/26/2017] [Indexed: 01/22/2023] Open
Abstract
α-Synuclein is a protein involved in the pathogenesis of synucleinopathies, including Parkinson’s disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). We investigated the role of neuronal α-Syn in myelin composition and abnormalities. The phospholipid content of purified myelin was determined by 31P NMR in two mouse lines modeling PD, PrP-A53T α-Syn and Thy-1 wt-α-Syn. Significantly higher levels of phospholipids were detected in myelin purified from brains of these α-Syn transgenic mouse models than in control mice. Nevertheless, myelin ultrastructure appeared intact. To further investigate the effect of α-Syn on myelin abnormalities, we systematically analyzed the striatum, a brain region associated with neurodegeneration in PD. An age and disease-dependent loss of myelin basic protein (MBP) signal was detected by immunohistochemistry in striatal striosomes (patches). The age-dependent loss of MBP signal was associated with lower P25α levels in oligodendrocytes. In addition, we found that α-Syn inhibited oligodendrocyte maturation and the formation of membranous sheets in vitro. Based on these results we concluded that neuronal α-Syn is involved in the regulation and/or maintenance of myelin phospholipid. However, axonal hypomyelination in the PD models is evident only in progressive stages of the disease and associated with α-Syn toxicity.
Collapse
|
29
|
Nykjaer CH, Brudek T, Salvesen L, Pakkenberg B. Changes in the cell population in brain white matter in multiple system atrophy. Mov Disord 2017; 32:1074-1082. [PMID: 28394027 DOI: 10.1002/mds.26979] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 02/02/2017] [Accepted: 02/25/2017] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Multiple system atrophy (MSA) is a sporadic progressive neurodegenerative disorder with adult onset and unknown etiology. Clinically it is characterized by autonomic failure, cerebellar ataxia, parkinsonism, and corticospinal dysfunction in any combination and with varying severity. OBJECTIVES AND METHODS To establish the extent of involvement of the white matter in the disease, we have used stereology to quantify the total number of neurons and glial cells (oligodendrocytes, astrocytes, and microglia) in the brains from 10 MSA patients and 11 controls. RESULTS The mean total number of white matter interstitial neurons in the patient brains was 0.5 × 109 (coefficient of variation = standard deviation/mean = 0.37), which was significantly lower than the 1.1 × 109 (0.41) in the control brains (P = .001) and equal to a reduction by ∼50%. The patient brains had a significantly higher number of white matter microglia, 1.5 × 109 (0.47) versus 0.7 × 109 (0.39) microglia in the control subjects (P = .003) and equal to an increase by ∼ 100%. There was no significant difference in mean total numbers of white matter oligodendrocytes and astrocytes between the groups. CONCLUSIONS We found widespread microgliosis without concomitant astrogliosis in brain white matter in MSA patients and demonstrated an absence of significant oligodendrocyte degeneration. The exact role of oligodendrocytes in MSA pathogenesis, including neurodegeneration, remains to be elucidated. © 2017 International Parkinson and Movement Disorder Society.
Collapse
Affiliation(s)
- Charlotte Havelund Nykjaer
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Copenhagen, Denmark
| | - Tomasz Brudek
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Copenhagen, Denmark
| | - Lisette Salvesen
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Copenhagen, Denmark.,Department of Neurology, Bispebjerg-Frederiksberg Hospital, Copenhagen, Denmark
| | - Bente Pakkenberg
- Research Laboratory for Stereology and Neuroscience, Bispebjerg-Frederiksberg Hospital, Copenhagen, Denmark.,Institute of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
30
|
Stefanova N, Wenning GK. Review: Multiple system atrophy: emerging targets for interventional therapies. Neuropathol Appl Neurobiol 2016; 42:20-32. [PMID: 26785838 PMCID: PMC4788141 DOI: 10.1111/nan.12304] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/13/2016] [Accepted: 01/20/2016] [Indexed: 12/21/2022]
Abstract
Multiple system atrophy (MSA) is a fatal orphan neurodegenerative disorder that manifests with rapidly progressive autonomic and motor dysfunction. The disease is characterized by the accumulation of α-synuclein fibrils in oligodendrocytes that form glial cytoplasmic inclusions, a neuropathological hallmark and central player in the pathogenesis of MSA. Here, we summarize the current knowledge on the etiopathogenesis and neuropathology of MSA. We discuss the role of α-synuclein pathology, microglial activation, oligodendroglial dysfunction and putative cell death mechanisms as candidate therapeutic targets in MSA.
Collapse
Affiliation(s)
- N Stefanova
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - G K Wenning
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
31
|
Jellinger KA, Wenning GK. Multiple system atrophy: pathogenic mechanisms and biomarkers. J Neural Transm (Vienna) 2016; 123:555-72. [PMID: 27098666 DOI: 10.1007/s00702-016-1545-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/31/2016] [Indexed: 12/13/2022]
Abstract
Multiple system atrophy (MSA) is a unique proteinopathy that differs from other α-synucleinopathies since the pathological process resulting from accumulation of aberrant α-synuclein (αSyn) involves the oligodendroglia rather than neurons, although both pathologies affect multiple parts of the brain, spinal cord, autonomic and peripheral nervous system. Both the etiology and pathogenesis of MSA are unknown, although animal models have provided insight into the basic molecular changes of this disorder. Accumulation of aberrant αSyn in oligodendroglial cells and preceded by relocation of p25α protein from myelin to oligodendroglia results in the formation of insoluble glial cytoplasmic inclusions that cause cell dysfunction and demise. These changes are associated with proteasomal, mitochondrial and lipid transport dysfunction, oxidative stress, reduced trophic transport, neuroinflammation and other noxious factors. Their complex interaction induces dysfunction of the oligodendroglial-myelin-axon-neuron complex, resulting in the system-specific pattern of neurodegeneration characterizing MSA as a synucleinopathy with oligodendroglio-neuronopathy. Propagation of modified toxic αSyn species from neurons to oligodendroglia by "prion-like" transfer and its spreading associated with neuronal pathways result in a multi-system involvement. No reliable biomarkers are currently available for the clinical diagnosis and prognosis of MSA. Multidisciplinary research to elucidate the genetic and molecular background of the deleterious cycle of noxious processes, to develop reliable diagnostic biomarkers and to deliver targets for effective treatment of this hitherto incurable disorder is urgently needed.
Collapse
Affiliation(s)
- Kurt A Jellinger
- Institute of Clinical Neurobiology, Alberichgasse 5/13, 1150, Vienna, Austria.
| | - Gregor K Wenning
- Division of Clinical Neurobiology, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
32
|
Schafferer S, Khurana R, Refolo V, Venezia S, Sturm E, Piatti P, Hechenberger C, Hackl H, Kessler R, Willi M, Gstir R, Krogsdam A, Lusser A, Poewe W, Wenning GK, Hüttenhofer A, Stefanova N. Changes in the miRNA-mRNA Regulatory Network Precede Motor Symptoms in a Mouse Model of Multiple System Atrophy: Clinical Implications. PLoS One 2016; 11:e0150705. [PMID: 26962858 PMCID: PMC4786272 DOI: 10.1371/journal.pone.0150705] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/18/2016] [Indexed: 12/31/2022] Open
Abstract
Multiple system atrophy (MSA) is a fatal rapidly progressive α-synucleinopathy, characterized by α-synuclein accumulation in oligodendrocytes. It is accepted that the pathological α-synuclein accumulation in the brain of MSA patients plays a leading role in the disease process, but little is known about the events in the early stages of the disease. In this study we aimed to define potential roles of the miRNA-mRNA regulatory network in the early pre-motor stages of the disease, i.e., downstream of α-synuclein accumulation in oligodendroglia, as assessed in a transgenic mouse model of MSA. We investigated the expression patterns of miRNAs and their mRNA targets in substantia nigra (SN) and striatum, two brain regions that undergo neurodegeneration at a later stage in the MSA model, by microarray and RNA-seq analysis, respectively. Analysis was performed at a time point when α-synuclein accumulation was already present in oligodendrocytes at neuropathological examination, but no neuronal loss nor deficits of motor function had yet occurred. Our data provide a first evidence for the leading role of gene dysregulation associated with deficits in immune and inflammatory responses in the very early, non-symptomatic disease stages of MSA. While dysfunctional homeostasis and oxidative stress were prominent in SN in the early stages of MSA, in striatum differential gene expression in the non-symptomatic phase was linked to oligodendroglial dysfunction, disturbed protein handling, lipid metabolism, transmembrane transport and altered cell death control, respectively. A large number of putative miRNA-mRNAs interaction partners were identified in relation to the control of these processes in the MSA model. Our results support the role of early changes in the miRNA-mRNA regulatory network in the pathogenesis of MSA preceding the clinical onset of the disease. The findings thus contribute to understanding the disease process and are likely to pave the way towards identifying disease biomarkers for early diagnosis of MSA.
Collapse
Affiliation(s)
- Simon Schafferer
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Rimpi Khurana
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Violetta Refolo
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innrain 66/G2, 6020 Innsbruck, Austria
| | - Serena Venezia
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innrain 66/G2, 6020 Innsbruck, Austria
| | - Edith Sturm
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innrain 66/G2, 6020 Innsbruck, Austria
| | - Paolo Piatti
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Clara Hechenberger
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Hubert Hackl
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Roman Kessler
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Michaela Willi
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Ronald Gstir
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Anne Krogsdam
- Division of Bioinformatics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Alexandra Lusser
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
| | - Werner Poewe
- Department of Neurology, Medical University of Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria
| | - Gregor K. Wenning
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innrain 66/G2, 6020 Innsbruck, Austria
| | - Alexander Hüttenhofer
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innrain 80–82, 6020 Innsbruck, Austria
- * E-mail: (NS); (AH)
| | - Nadia Stefanova
- Division of Neurobiology, Department of Neurology, Medical University of Innsbruck, Innrain 66/G2, 6020 Innsbruck, Austria
- * E-mail: (NS); (AH)
| |
Collapse
|
33
|
Heng Y, Zhang QS, Mu Z, Hu JF, Yuan YH, Chen NH. Ginsenoside Rg1 attenuates motor impairment and neuroinflammation in the MPTP-probenecid-induced parkinsonism mouse model by targeting α-synuclein abnormalities in the substantia nigra. Toxicol Lett 2015; 243:7-21. [PMID: 26723869 DOI: 10.1016/j.toxlet.2015.12.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/14/2015] [Accepted: 12/21/2015] [Indexed: 11/27/2022]
Abstract
Parkinson's disease (PD) is pathologically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the accumulation of aggregated α-synuclein in specific central nervous system (CNS) regions. Disease development is attributed to α-synuclein abnormalities, particularly aggregation and phosphorylation. The ginsenoside Rg1, an active component of ginseng, possesses neuroprotective and anti-inflammatory effects. The purpose of the present study was to evaluate these activities of Rg1 in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)/probenecid (MPTP/p)-induced PD mouse model for the first time and to elucidate the underlying mechanisms. Oral treatment with Rg1 significantly attenuated the high MPTP-induced mortality, behavior defects, loss of dopamine neurons and abnormal ultrastructure changes in the SNpc. Other assays indicated that the protective effect of Rg1 may be mediated by its anti-neuroinflammatory properties. Rg1 regulated MPTP-induced reactive astrocytes and microglia and decreased the release of cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the SNpc. Rg1 also alleviated the unusual MPTP-induced increase in oligomeric, phosphorylated and disease-related α-synuclein in the SNpc. In conclusion, Rg1 protects dopaminergic neurons, most likely by reducing aberrant α-synuclein-mediated neuroinflammation, and holds promise for PD therapeutics.
Collapse
Affiliation(s)
- Yang Heng
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Qiu-Shuang Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Zheng Mu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Jin-Feng Hu
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yu-He Yuan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; College of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China.
| |
Collapse
|
34
|
MyelStones: the executive roles of myelin basic protein in myelin assembly and destabilization in multiple sclerosis. Biochem J 2015; 472:17-32. [DOI: 10.1042/bj20150710] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The classic isoforms of myelin basic protein (MBP, 14–21.5 kDa) are essential to formation of the multilamellar myelin sheath of the mammalian central nervous system (CNS). The predominant 18.5-kDa isoform links together the cytosolic surfaces of oligodendrocytes, but additionally participates in cytoskeletal turnover and membrane extension, Fyn-mediated signalling pathways, sequestration of phosphoinositides and maintenance of calcium homoeostasis. All MBP isoforms are intrinsically disordered proteins (IDPs) that interact via molecular recognition fragments (MoRFs), which thereby undergo local disorder-to-order transitions. Their conformations and associations are modulated by environment and by a dynamic barcode of post-translational modifications, particularly phosphorylation by mitogen-activated and other protein kinases and deimination [a hallmark of demyelination in multiple sclerosis (MS)]. The MBPs are thus to myelin what basic histones are to chromatin. Originally thought to be merely structural proteins forming an inert spool, histones are now known to be dynamic entities involved in epigenetic regulation and diseases such as cancer. Analogously, the MBPs are not mere adhesives of compact myelin, but active participants in oligodendrocyte proliferation and in membrane process extension and stabilization during myelinogenesis. A central segment of these proteins is pivotal in membrane-anchoring and SH3 domain (Src homology 3) interaction. We discuss in the present review advances in our understanding of conformational conversions of this classic basic protein upon membrane association, including new thermodynamic analyses of transitions into different structural ensembles and how a shift in the pattern of its post-translational modifications is associated with the pathogenesis and potentially onset of demyelination in MS.
Collapse
|
35
|
Abstract
Vertebrate myelination is an evolutionary advancement essential for motor, sensory, and higher-order cognitive function. CNS myelin, a multilamellar differentiation of the oligodendrocyte plasma membrane, ensheaths axons to facilitate electrical conduction. Myelination is one of the most pivotal cell-cell interactions for normal brain development, involving extensive information exchange between differentiating oligodendrocytes and axons. The molecular mechanisms of myelination are discussed, along with new perspectives on oligodendrocyte plasticity and myelin remodeling of the developing and adult CNS.
Collapse
|