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Shen YX, Lee PS, Teng MC, Huang JH, Wang CC, Fan HF. Influence of Cigarette Aerosol in Alpha-Synuclein Oligomerization and Cell Viability in SH-SY5Y: Implications for Parkinson's Disease. ACS Chem Neurosci 2024; 15:1484-1500. [PMID: 38483468 PMCID: PMC10995954 DOI: 10.1021/acschemneuro.3c00771] [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: 11/29/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Abstract
Although cigarette aerosol exposure is associated with various adverse health issues, its impact on Parkinson's disease (PD) remains elusive. Here, we investigated the effect of cigarette aerosol extract (CAE) on SH-SY5Y cells for the first time, both with and without α-synuclein (α-Syn) overexpression. We found that α-Syn aggravates CAE-induced cell death, oxidative stress, and mitochondrial dysfunction. Fluorescence cross-correlation spectroscopy (FCCS) revealed a dual distribution of α-Syn within the cells, with homogeneous regions indicative of monomeric α-Syn and punctated regions, suggesting the formation of oligomers. Moreover, we observed colocalization of α-Syn oligomers with lysosomes along with a reduction in autophagy activity. These findings suggest that α-Syn overexpression exacerbates CAE-induced intracellular cytotoxicity, mitochondrial dysfunction, and autophagy dysregulation, leading to elevated cell mortality. Our findings provide new insights into the pathogenic mechanisms linking exposure to cigarette aerosols with neurodegenerative diseases.
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Affiliation(s)
- Yu-Xin Shen
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Pe-Shuen Lee
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Ming-Chu Teng
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Jhih-Hong Huang
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Chia C. Wang
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Hsiu-Fang Fan
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
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Zalon AJ, Quiriconi DJ, Pitcairn C, Mazzulli JR. α-Synuclein: Multiple pathogenic roles in trafficking and proteostasis pathways in Parkinson's disease. Neuroscientist 2024:10738584241232963. [PMID: 38420922 DOI: 10.1177/10738584241232963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Parkinson's disease (PD) is a common age-related neurodegenerative disorder characterized by the loss of dopaminergic neurons in the midbrain. A hallmark of both familial and sporadic PD is the presence of Lewy body inclusions composed mainly of aggregated α-synuclein (α-syn), a presynaptic protein encoded by the SNCA gene. The mechanisms driving the relationship between α-syn accumulation and neurodegeneration are not completely understood, although recent evidence indicates that multiple branches of the proteostasis pathway are simultaneously perturbed when α-syn aberrantly accumulates within neurons. Studies from patient-derived midbrain cultures that develop α-syn pathology through the endogenous expression of PD-causing mutations show that proteostasis disruption occurs at the level of synthesis/folding in the endoplasmic reticulum (ER), downstream ER-Golgi trafficking, and autophagic-lysosomal clearance. Here, we review the fundamentals of protein transport, highlighting the specific steps where α-syn accumulation may intervene and the downstream effects on proteostasis. Current therapeutic efforts are focused on targeting single pathways or proteins, but the multifaceted pathogenic role of α-syn throughout the proteostasis pathway suggests that manipulating several targets simultaneously will provide more effective disease-modifying therapies for PD and other synucleinopathies.
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Affiliation(s)
- Annie J Zalon
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Drew J Quiriconi
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Caleb Pitcairn
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Joseph R Mazzulli
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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3
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Nordengen K, Morland C. From Synaptic Physiology to Synaptic Pathology: The Enigma of α-Synuclein. Int J Mol Sci 2024; 25:986. [PMID: 38256059 PMCID: PMC10815905 DOI: 10.3390/ijms25020986] [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: 11/30/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
Alpha-synuclein (α-syn) has gained significant attention due to its involvement in neurodegenerative diseases, particularly Parkinson's disease. However, its normal function in the human brain is equally fascinating. The α-syn protein is highly dynamic and can adapt to various conformational stages, which differ in their interaction with synaptic elements, their propensity to drive pathological aggregation, and their toxicity. This review will delve into the multifaceted role of α-syn in different types of synapses, shedding light on contributions to neurotransmission and overall brain function. We describe the physiological role of α-syn at central synapses, including the bidirectional interaction between α-syn and neurotransmitter systems.
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Affiliation(s)
- Kaja Nordengen
- Department of Neurology, Oslo University Hospital, 0424 Oslo, Norway
| | - Cecilie Morland
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, The Faculty of Mathematics and Natural Sciences, University of Oslo, 1068 Oslo, Norway
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Limanaqi F, Zecchini S, Saulle I, Strizzi S, Vanetti C, Garziano M, Cappelletti G, Parolin D, Caccia S, Trabattoni D, Fenizia C, Clerici M, Biasin M. Alpha-synuclein dynamics bridge Type-I Interferon response and SARS-CoV-2 replication in peripheral cells. Biol Res 2024; 57:2. [PMID: 38191441 PMCID: PMC10775536 DOI: 10.1186/s40659-023-00482-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 12/15/2023] [Indexed: 01/10/2024] Open
Abstract
BACKGROUND Increasing evidence suggests a double-faceted role of alpha-synuclein (α-syn) following infection by a variety of viruses, including SARS-CoV-2. Although α-syn accumulation is known to contribute to cell toxicity and the development and/or exacerbation of neuropathological manifestations, it is also a key to sustaining anti-viral innate immunity. Consistently with α-syn aggregation as a hallmark of Parkinson's disease, most studies investigating the biological function of α-syn focused on neural cells, while reports on the role of α-syn in periphery are limited, especially in SARS-CoV-2 infection. RESULTS Results herein obtained by real time qPCR, immunofluorescence and western blot indicate that α-syn upregulation in peripheral cells occurs as a Type-I Interferon (IFN)-related response against SARS-CoV-2 infection. Noteworthy, this effect mostly involves α-syn multimers, and the dynamic α-syn multimer:monomer ratio. Administration of excess α-syn monomers promoted SARS-CoV-2 replication along with downregulation of IFN-Stimulated Genes (ISGs) in epithelial lung cells, which was associated with reduced α-syn multimers and α-syn multimer:monomer ratio. These effects were prevented by combined administration of IFN-β, which hindered virus replication and upregulated ISGs, meanwhile increasing both α-syn multimers and α-syn multimer:monomer ratio in the absence of cell toxicity. Finally, in endothelial cells displaying abortive SARS-CoV-2 replication, α-syn multimers, and multimer:monomer ratio were not reduced following exposure to the virus and exogenous α-syn, suggesting that only productive viral infection impairs α-syn multimerization and multimer:monomer equilibrium. CONCLUSIONS Our study provides novel insights into the biology of α-syn, showing that its dynamic conformations are implicated in the innate immune response against SARS-CoV-2 infection in peripheral cells. In particular, our results suggest that promotion of non-toxic α-syn multimers likely occurs as a Type-I IFN-related biological response which partakes in the suppression of viral replication. Further studies are needed to replicate our findings in neuronal cells as well as animal models, and to ascertain the nature of such α-syn conformations.
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Affiliation(s)
- Fiona Limanaqi
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy.
| | - Silvia Zecchini
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Irma Saulle
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza, Milan, Italy
| | - Sergio Strizzi
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Claudia Vanetti
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Micaela Garziano
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza, Milan, Italy
| | - Gioia Cappelletti
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Debora Parolin
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Sonia Caccia
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Daria Trabattoni
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
| | - Claudio Fenizia
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza, Milan, Italy
| | - Mario Clerici
- Department of Pathophysiology and Transplantation, University of Milan, Via Francesco Sforza, Milan, Italy
- IRCCS Fondazione Don Carlo Gnocchi, 20148, Milan, Italy
| | - Mara Biasin
- Department of Biomedical and Clinical Sciences, University of Milan, Via G.B. Grassi, Milan, Italy.
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5
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Moors TE, Milovanovic D. Defining a Lewy Body: Running Up the Hill of Shifting Definitions and Evolving Concepts. JOURNAL OF PARKINSON'S DISEASE 2024; 14:17-33. [PMID: 38189713 PMCID: PMC10836569 DOI: 10.3233/jpd-230183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Lewy bodies (LBs) are pathological hallmarks of Parkinson's disease and dementia with Lewy bodies, characterized by the accumulation of α-synuclein (αSyn) protein in the brain. While LBs were first described a century ago, their formation and morphogenesis mechanisms remain incompletely understood. Here, we present a historical overview of LB definitions and highlight the importance of semantic clarity and precise definitions when describing brain inclusions. Recent breakthroughs in imaging revealed shared features within LB subsets and the enrichment of membrane-bound organelles in these structures, challenging the conventional LB formation model. We discuss the involvement of emerging concepts of liquid-liquid phase separation, where biomolecules demix from a solution to form dense condensates, as a potential LB formation mechanism. Finally, we emphasize the need for the operational definitions of LBs based on morphological characteristics and detection protocols, particularly in studies investigating LB formation mechanisms. A better understanding of LB organization and ultrastructure can contribute to the development of targeted therapeutic strategies for synucleinopathies.
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Affiliation(s)
- Tim E Moors
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Dragomir Milovanovic
- Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
- Einstein Center for Neuroscience, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Berlin, Germany
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6
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Shimanaka K, Shi B, Brontesi L, Alnakhala H, Jayanthi V, Subramanian K, Ramalingam N, Tripathi A, Dettmer U. Adding hydrophobicity or positive charges to the cytosolic half of the α-synuclein 3-11 helix increases membrane association and S129 phosphorylation. FEBS Lett 2024; 598:210-219. [PMID: 37989349 PMCID: PMC10842440 DOI: 10.1002/1873-3468.14773] [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: 05/30/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 11/23/2023]
Abstract
The neuronal protein α-synuclein is centrally involved in the neurodegeneration occurring in Parkinson's disease and related synucleinopathies. α-Synuclein's membrane-induced 3-11 helix conformation has a hydrophobic membrane-embedded half and a hydrophilic cytosolic half. Here, we studied the significance of (a) the surprising hydrophobicity of amino-acids at cytosol-exposed helix position 8; (b) the absence of positively charged lysine/arginine from all cytosol-exposed positions (1-5-8-9). We found that (a) further increasing hydrophobicity or adding lysine, but not glutamate, at position 8 augments both membrane interaction and S129 phosphorylation; (b) adding lysines at cytosol-exposed positions 1, 5, 8, or 9 has similar effects. Variants abundantly present in membranes by biochemical fractionation markedly colocalized with transferrin-receptor (an endosomal marker) in immunofluorescence-microscopy, indicating accumulation at vesicle membranes. Thus, we observed a striking correlation between membrane attraction and S129 phosphorylation, relevant for understanding α-synuclein biology in health and disease.
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Affiliation(s)
- Kazuma Shimanaka
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Bryan Shi
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Lisa Brontesi
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Heba Alnakhala
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Vidyashree Jayanthi
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Kanagaraj Subramanian
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Arati Tripathi
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
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7
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Wallace JN, Crockford ZC, Román-Vendrell C, Brady EB, Hoffmann C, Vargas KJ, Potcoava M, Wegman ME, Alford ST, Milovanovic D, Morgan JR. Excess phosphoserine-129 α-synuclein induces synaptic vesicle trafficking and declustering defects at a vertebrate synapse. Mol Biol Cell 2024; 35:ar10. [PMID: 37991902 PMCID: PMC10881165 DOI: 10.1091/mbc.e23-07-0269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/06/2023] [Accepted: 11/06/2023] [Indexed: 11/24/2023] Open
Abstract
α-Synuclein is a presynaptic protein that regulates synaptic vesicle (SV) trafficking. In Parkinson's disease (PD) and dementia with Lewy bodies (DLB), α-synuclein aberrantly accumulates throughout neurons, including at synapses. During neuronal activity, α-synuclein is reversibly phosphorylated at serine 129 (pS129). While pS129 comprises ∼4% of total α-synuclein under physiological conditions, it dramatically increases in PD and DLB brains. The impacts of excess pS129 on synaptic function are currently unknown. We show here that compared with wild-type (WT) α-synuclein, pS129 exhibits increased binding and oligomerization on synaptic membranes and enhanced vesicle "microclustering" in vitro. Moreover, when acutely injected into lamprey reticulospinal axons, excess pS129 α-synuclein robustly localized to synapses and disrupted SV trafficking in an activity-dependent manner, as assessed by ultrastructural analysis. Specifically, pS129 caused a declustering and dispersion of SVs away from the synaptic vicinity, leading to a significant loss of total synaptic membrane. Live imaging further revealed altered SV cycling, as well as microclusters of recently endocytosed SVs moving away from synapses. Thus, excess pS129 caused an activity-dependent inhibition of SV trafficking via altered vesicle clustering/reclustering. This work suggests that accumulation of pS129 at synapses in diseases like PD and DLB could have profound effects on SV dynamics.
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Affiliation(s)
| | | | | | - Emily B. Brady
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, and
| | - Christian Hoffmann
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543
- Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
| | - Karina J. Vargas
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, and
- Department of Cell Biology, University of Pittsburgh, PA 15261
| | - Mariana Potcoava
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | | | - Simon T. Alford
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612
| | - Dragomir Milovanovic
- Whitman Center, Marine Biological Laboratory, Woods Hole, MA 02543
- Laboratory of Molecular Neuroscience, German Center for Neurodegenerative Diseases (DZNE), 10117 Berlin, Germany
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8
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Ramalingam N, Brontesi L, Jin S, Selkoe DJ, Dettmer U. Dynamic reversibility of α-synuclein serine-129 phosphorylation is impaired in synucleinopathy models. EMBO Rep 2023; 24:e57145. [PMID: 37870370 PMCID: PMC10702791 DOI: 10.15252/embr.202357145] [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: 03/08/2023] [Revised: 09/28/2023] [Accepted: 10/06/2023] [Indexed: 10/24/2023] Open
Abstract
α-Synuclein phosphorylation at serine-129 (pS129) is a widely used surrogate marker of pathology in Parkinson's disease and other synucleinopathies. However, we recently demonstrated that phosphorylation of S129 is also a physiological activator of synaptic transmission. In a feed-forward fashion, neuronal activity triggers reversible pS129. Here, we show that Parkinson's disease-linked missense mutations in SNCA impact activity-dependent pS129. Under basal conditions, cytosol-enriched A30P, H50Q, and G51D mutant forms of α-synuclein exhibit reduced pS129 levels in rat primary cortical neurons. A53T pS129 levels are similar to wild-type, and E46K pS129 levels are higher. A30P and E46K mutants show impaired reversibility of pS129 after stimulation. For the engineered profoundly membrane-associated α-synuclein mutant "3K" (E35K + E46K + E61K), de-phosphorylation was virtually absent after blocking stimulation, implying that reversible pS129 is severely compromised. Importantly, pS129 excess resulting from proteasome inhibition is also associated with reduced reversibility by neuronal inhibition, kinase inhibition, or phosphatase activation. Our findings suggest that perturbed pS129 dynamics are probably a shared characteristic of pathology-associated α-synuclein, with possible implications for synucleinopathy treatment and diagnosis.
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Affiliation(s)
- Nagendran Ramalingam
- Ann Romney Center for Neurologic DiseasesBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Lisa Brontesi
- Ann Romney Center for Neurologic DiseasesBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Shan‐Xue Jin
- Ann Romney Center for Neurologic DiseasesBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic DiseasesBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
| | - Ulf Dettmer
- Ann Romney Center for Neurologic DiseasesBrigham and Women's Hospital and Harvard Medical SchoolBostonMAUSA
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9
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Flores-Leon M, Outeiro TF. More than meets the eye in Parkinson's disease and other synucleinopathies: from proteinopathy to lipidopathy. Acta Neuropathol 2023; 146:369-385. [PMID: 37421475 PMCID: PMC10412683 DOI: 10.1007/s00401-023-02601-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 07/10/2023]
Abstract
The accumulation of proteinaceous inclusions in the brain is a common feature among neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease (PD), and dementia with Lewy bodies (DLB). The main neuropathological hallmark of PD and DLB are inclusions, known as Lewy bodies (LBs), enriched not only in α-synuclein (aSyn), but also in lipid species, organelles, membranes, and even nucleic acids. Furthermore, several genetic risk factors for PD are mutations in genes involved in lipid metabolism, such as GBA1, VSP35, or PINK1. Thus, it is not surprising that mechanisms that have been implicated in PD, such as inflammation, altered intracellular and vesicular trafficking, mitochondrial dysfunction, and alterations in the protein degradation systems, may be also directly or indirectly connected through lipid homeostasis. In this review, we highlight and discuss the recent evidence that suggests lipid biology as important drivers of PD, and which require renovated attention by neuropathologists. Particularly, we address the implication of lipids in aSyn accumulation and in the spreading of aSyn pathology, in mitochondrial dysfunction, and in ER stress. Together, this suggests we should broaden the view of PD not only as a proteinopathy but also as a lipidopathy.
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Affiliation(s)
- Manuel Flores-Leon
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37073, Göttingen, Germany
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, Mexico
| | - Tiago Fleming Outeiro
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37073, Göttingen, Germany.
- Max Planck Institute for Multidisciplinary Science, Göttingen, Germany.
- Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK.
- Scientific Employee with an Honorary Contract at Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Göttingen, Germany.
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10
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Zenko D, Marsh J, Castle AR, Lewin R, Fischer R, Tofaris GK. Monitoring α-synuclein ubiquitination dynamics reveals key endosomal effectors mediating its trafficking and degradation. SCIENCE ADVANCES 2023; 9:eadd8910. [PMID: 37315142 PMCID: PMC10266730 DOI: 10.1126/sciadv.add8910] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 05/08/2023] [Indexed: 06/16/2023]
Abstract
While defective α-synuclein homeostasis is central to Parkinson's pathogenesis, fundamental questions about its degradation remain unresolved. We have developed a bimolecular fluorescence complementation assay in living cells to monitor de novo ubiquitination of α-synuclein and identified lysine residues 45, 58, and 60 as critical ubiquitination sites for its degradation. This is mediated by NBR1 binding and entry into endosomes in a process that involves ESCRT I-III for subsequent lysosomal degradation. Autophagy or the autophagic chaperone Hsc70 is dispensable for this pathway. Antibodies against diglycine-modified α-synuclein peptides confirmed that endogenous α-synuclein is similarly ubiquitinated in the brain and targeted to lysosomes in primary and iPSC-derived neurons. Ubiquitinated α-synuclein was detected in Lewy bodies and cellular models of aggregation, suggesting that it may be entrapped with endo/lysosomes in inclusions. Our data elucidate the intracellular trafficking of de novo ubiquitinated α-synuclein and provide tools for investigating the rapidly turned-over fraction of this disease-causing protein.
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Affiliation(s)
- Dmitry Zenko
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Jade Marsh
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Andrew R. Castle
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Rahel Lewin
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - George K. Tofaris
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
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11
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Ramirez E, Ganegamage SK, Elbatrawy AA, Alnakhala H, Shimanaka K, Tripathi A, Min S, Rochet JC, Dettmer U, Fortin JS. 5-Nitro-1,2-benzothiazol-3-amine and N-Ethyl-1-[(ethylcarbamoyl)(5-nitro-1,2-benzothiazol-3-yl)amino]formamide Modulate α-Synuclein and Tau Aggregation. ACS OMEGA 2023; 8:20102-20115. [PMID: 37305264 PMCID: PMC10249125 DOI: 10.1021/acsomega.3c02668] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023]
Abstract
Protein misfolding results in a plethora of known diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, transthyretin-related amyloidosis, type 2 diabetes, Lewy body dementia, and spongiform encephalopathy. To provide a diverse portfolio of therapeutic small molecules with the ability to reduce protein misfolding, we evaluated a set of 13 compounds: 4-(benzo[d]thiazol-2-yl)aniline (BTA) and its derivatives containing urea (1), thiourea (2), sulfonamide (3), triazole (4), and triazine (5) linker. In addition, we explored small modifications on a very potent antioligomer 5-nitro-1,2-benzothiazol-3-amine (5-NBA) (compounds 6-13). This study aims to define the activity of BTA and its derivatives on a variety of prone-to-aggregate proteins such as transthyretin (TTR81-127, TTR101-125), α-synuclein (α-syn), and tau isoform 2N4R (tau 2N4R) through various biophysical methods. Thioflavin T (ThT) fluorescence assay was used to monitor fibril formation of the previously mentioned proteins after treatment with BTA and its derivatives. Antifibrillary activity was confirmed using transmission electron microscopy (TEM). Photoreactive cross-linking assay (PICUP) was utilized to detect antioligomer activity and lead to the identification of 5-NBA (at low micromolar concentration) and compound 13 (at high concentration) as the most promising in reducing oligomerization. 5-NBA and not BTA inhibited the inclusion formation based on the cell-based assay using M17D neuroblastoma cells that express inclusion-prone αS-3K::YFP. 5-NBA abrogated the fibril, oligomer, and inclusion formation in a dose-dependent manner. 5-NBA derivatives could be the key to mitigate protein aggregation. In the future, the results made from this study will provide an initial platform to generate more potent inhibitors of α-syn and tau 2N4R oligomer and fibril formation.
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Affiliation(s)
- Eduardo Ramirez
- Department
of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West
Lafayette, Indiana 47907, United States
| | - Susantha K. Ganegamage
- Department
of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West
Lafayette, Indiana 47907, United States
| | - Ahmed A. Elbatrawy
- Department
of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West
Lafayette, Indiana 47907, United States
| | - Heba Alnakhala
- Department
of Neurology, Brigham and Women’s Hospital and Harvard Medical
School, Ann Romney Center for Neurologic
Diseases, Boston, Massachusetts 02115, United States
| | - Kazuma Shimanaka
- Department
of Neurology, Brigham and Women’s Hospital and Harvard Medical
School, Ann Romney Center for Neurologic
Diseases, Boston, Massachusetts 02115, United States
| | - Arati Tripathi
- Department
of Neurology, Brigham and Women’s Hospital and Harvard Medical
School, Ann Romney Center for Neurologic
Diseases, Boston, Massachusetts 02115, United States
| | - Sehong Min
- Department
of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana 47906, United States
| | - Jean-Christophe Rochet
- Department
of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, Indiana 47906, United States
| | - Ulf Dettmer
- Department
of Neurology, Brigham and Women’s Hospital and Harvard Medical
School, Ann Romney Center for Neurologic
Diseases, Boston, Massachusetts 02115, United States
| | - Jessica S. Fortin
- Department
of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West
Lafayette, Indiana 47907, United States
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12
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Nuber S, Selkoe DJ. The Parkinson-Associated Toxin Paraquat Shifts Physiological α-Synuclein Tetramers toward Monomers That Can Be Calpain-Truncated and Form Oligomers. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:520-531. [PMID: 36773784 PMCID: PMC10155269 DOI: 10.1016/j.ajpath.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/09/2023] [Accepted: 01/24/2023] [Indexed: 02/11/2023]
Abstract
Abnormal aggregation of α-synuclein (αS) is thought to initiate neuronal dysfunction and death in Parkinson disease (PD). In addition to higher-molecular-weight, oligomeric, and polymeric forms of αS associated with neurotoxicity and disease, recent findings indicate the occurrence of physiological tetrameric assemblies in healthy neurons in culture and in brain. Herein, the PD-associated neurotoxin paraquat reduced physiological tetramers and led to calpain-truncated monomers and an approximately 70-kDa apparent oligomer different in size from physiological αS multimers. These truncated and oligomeric forms could also be generated by calpain cleavage of pure, recombinant human αS in vitro. Moreover, they were detected in the brains of tetramer-abrogating, E46K-amplified (3K) mice that model PD. These results indicate that paraquat triggers membrane damage and aberrant calpain activity that can induce a pathologic shift of tetramers toward an excess of full-length and truncated monomers, the accumulation of αS oligomers, and insoluble cytoplasmic αS puncta. The findings suggest that an environmental precipitant of PD can alter αS tetramer/monomer equilibrium, as already shown for several genetically caused forms of PD.
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Affiliation(s)
- Silke Nuber
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Mass General Brigham, Harvard Medical School, Boston, Massachusetts.
| | - Dennis J Selkoe
- Department of Neurology, Ann Romney Center for Neurologic Diseases, Mass General Brigham, Harvard Medical School, Boston, Massachusetts
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13
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Brontesi L, Imberdis T, Ramalingam N, Dettmer U. The effects of KTKEGV repeat motif and intervening ATVA sequence on α-synuclein solubility and assembly. J Neurochem 2023; 165:246-258. [PMID: 36625497 PMCID: PMC10211470 DOI: 10.1111/jnc.15763] [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: 02/15/2022] [Revised: 12/15/2022] [Accepted: 12/19/2022] [Indexed: 01/11/2023]
Abstract
Alpha-synuclein (αS), the key protein in Parkinson's disease, is typically described as an intrinsically disordered protein. Consistent with this notion, several context-dependent folding states may coexist in neurons. Unfolded soluble monomers, helical monomers at membranes and helical multimers (soluble or at membranes) have all been reported and may be in an equilibrium with each other. We previously found that αS can be stabilized in its membrane-associated monomeric form by genetically increasing the hydrophobicity of the membrane-embedded half of the αS helix. αS amphipathic helix formation at membranes is governed by up to nine 11-amino acid repeats with the core motif KTKEGV. However, this repeat is only imperfectly conserved; for example, it consists of KAKEGV in repeat #1, KTKEQV in repeat #5, and AVVTGV in the poorly conserved repeat #6. Here we explored the effect of perfecting the αS core repeat to nine times KTKEGV ("9KV") and found by sequential protein extraction that this engineered mutant accumulates in the cytosolic phase of neural cells. Intact-cell cross-linking trapped a part of the cytosolic portion at multimeric positions (30, 60, 80, 100 kDa). Thus, compared to wild-type αS, αS 9KV seems less prone to populating the membrane-associated monomeric form. Removing the "ATVA" intervening amino-acid sequence between repeats 4 and 5 slightly increased cytosolic localization while adding "ATVA" in between all repeats 1-8 caused αS to be trapped as a monomer in membrane fractions. Our results contribute to an ongoing debate on the dynamic structure of αS, highlighting that wild-type αS is unlikely to be fully multimeric/monomeric or fully cytosolic/membrane-associated in cells, but protein engineering can create αS variants that preferentially adopt a certain state. Overall, the imperfect nature of the KTKEGV repeat motifs and the presence of ATVA in between repeats 4 and 5 seem to prevent a strong cytosolic localization of αS and thus play a major role in the protein's ability to dynamically populate cytosolic vs. membrane-associated and monomeric vs. multimeric states.
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Affiliation(s)
| | | | - Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115 USA
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14
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Shendge AA, D’Souza JS. Strategic optimization of conditions for the solubilization of GST-tagged amphipathic helix-containing ciliary proteins overexpressed as inclusion bodies in E. coli. Microb Cell Fact 2022; 21:258. [PMID: 36510188 PMCID: PMC9746132 DOI: 10.1186/s12934-022-01979-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
Expression of affinity-tagged recombinant proteins for crystallography, protein-protein interaction, antibody generation, therapeutic applications, etc. mandates the generation of high-yield soluble proteins. Although recent developments suggest the use of yeast, insect, and mammalian cell lines as protein expression platforms, Escherichia coli is still the most popular, due mainly to its ease of growth, feasibility in genetic manipulation and economy. However, some proteins have a spontaneous tendency to form inclusion bodies (IBs) when over-expressed in bacterial expression systems such as E. coli, thus posing a challenge in purification and yield. At times, small peptides undergo degradation during protein production and hence using suitable tags could circumvent the problem. Although several independent techniques have been used to solubilize IBs, these cannot always be applied in a generic sense. Although tagging a GST moiety is known to enhance the solubility of fusion proteins in E. coli, resulting in yields of 10-50 mg/L of the culture, the inherent nature of the protein sequence at times could lead to the formation of IBs. We have been working on a Myc Binding Protein-1 orthologue, viz. Flagellar Associated Protein 174 (FAP174) from the axoneme of Chlamydomonas reinhardtii that binds to an A-Kinase Anchoring Protein 240 (AKAP240) which has been annotated as Flagellar Associated Protein 65 (FAP65). Using an in-silico approach, we have identified two amphipathic helices on FAP65 (CrFAP65AH1 and CrFAP65AH2) that are predicted to bind to FAP174. To test this prediction, we have cloned the GST-tagged peptides, and overexpressed them in E. coli that have resulted in insoluble IBs. The yields of these over-expressed recombinant proteins dropped considerably due to IB formation, indicating aggregation. An integrated approach has been used to solubilize four highly hydrophobic polypeptides, viz. two amphipathic helices and the respective proline variants of FAP65. For solubilizing these polypeptides, variables such as non-denaturing detergents (IGEPAL CA-630), changing the ionic strength of the cell lysis and solubilization buffer, addition of BugBuster®, diluting the cell lysate and sonication were introduced. Our statistically viable results yielded highly soluble and functional polypeptides, indiscreet secondary structures, and a yield of ~ 20 mg/L of the E. coli culture. Our combinatorial strategy using chemical and physical methods to solubilize IBs could prove useful for hydrophobic peptides and proteins with amphipathic helices.
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Affiliation(s)
- Amruta A. Shendge
- grid.452882.10000 0004 1761 3305School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, Kalina campus, Santacruz (E), Mumbai, 400098 India
| | - Jacinta S. D’Souza
- grid.452882.10000 0004 1761 3305School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, Kalina campus, Santacruz (E), Mumbai, 400098 India
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15
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Yoo G, An HJ, Yeou S, Lee NK. α-Synuclein Disrupts Vesicle Fusion by Two Mutant-Specific Mechanisms. Mol Cells 2022; 45:806-819. [PMID: 36380732 PMCID: PMC9676983 DOI: 10.14348/molcells.2022.0102] [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: 06/23/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 11/17/2022] Open
Abstract
Synaptic accumulation of α-synuclein (α-Syn) oligomers and their interactions with VAMP2 have been reported to be the basis of synaptic dysfunction in Parkinson's disease (PD). α-Syn mutants associated with familial PD have also been known to be capable of interacting with VAMP2, but the exact mechanisms resulting from those interactions to eventual synaptic dysfunction are still unclear. Here, we investigate the effect of α-Syn mutant oligomers comprising A30P, E46K, and A53T on VAMP2-embedded vesicles. Specifically, A30P and A53T oligomers cluster vesicles in the presence of VAMP2, which is a shared mechanism with wild type α-Syn oligomers induced by dopamine. On the other hand, E46K oligomers reduce the membrane mobility of the planar bilayers, as revealed by single-particle tracking, and permeabilize the membranes in the presence of VAMP2. In the absence of VAMP2 interactions, E46K oligomers enlarge vesicles by fusing with one another. Our results clearly demonstrate that α-Syn mutant oligomers have aberrant effects on VAMP2-embedded vesicles and the disruption types are distinct depending on the mutant types. This work may provide one of the possible clues to explain the α-Syn mutant-type dependent pathological heterogeneity of familial PD.
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Affiliation(s)
- Gyeongji Yoo
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Hyeong Jeon An
- Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Sanghun Yeou
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University, Seoul 08826, Korea
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16
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Vallés AS, Barrantes FJ. Interactions between the Nicotinic and Endocannabinoid Receptors at the Plasma Membrane. MEMBRANES 2022; 12:812. [PMID: 36005727 PMCID: PMC9414690 DOI: 10.3390/membranes12080812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Compartmentalization, together with transbilayer and lateral asymmetries, provide the structural foundation for functional specializations at the cell surface, including the active role of the lipid microenvironment in the modulation of membrane-bound proteins. The chemical synapse, the site where neurotransmitter-coded signals are decoded by neurotransmitter receptors, adds another layer of complexity to the plasma membrane architectural intricacy, mainly due to the need to accommodate a sizeable number of molecules in a minute subcellular compartment with dimensions barely reaching the micrometer. In this review, we discuss how nature has developed suitable adjustments to accommodate different types of membrane-bound receptors and scaffolding proteins via membrane microdomains, and how this "effort-sharing" mechanism has evolved to optimize crosstalk, separation, or coupling, where/when appropriate. We focus on a fast ligand-gated neurotransmitter receptor, the nicotinic acetylcholine receptor, and a second-messenger G-protein coupled receptor, the cannabinoid receptor, as a paradigmatic example.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca 8000, Argentina
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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17
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Fanning S, Cirka H, Thies JL, Jeong J, Niemi SM, Yoon J, Ho GPH, Pacheco JA, Dettmer U, Liu L, Clish CB, Hodgetts KJ, Hutchinson JN, Muratore CR, Caldwell GA, Caldwell KA, Selkoe D. Lipase regulation of cellular fatty acid homeostasis as a Parkinson's disease therapeutic strategy. NPJ Parkinsons Dis 2022; 8:74. [PMID: 35680956 PMCID: PMC9184586 DOI: 10.1038/s41531-022-00335-6] [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: 03/22/2022] [Accepted: 05/11/2022] [Indexed: 02/01/2023] Open
Abstract
Synucleinopathy (Parkinson's disease (PD); Lewy body dementia) disease-modifying treatments represent a huge unmet medical need. Although the PD-causing protein α-synuclein (αS) interacts with lipids and fatty acids (FA) physiologically and pathologically, targeting FA homeostasis for therapeutics is in its infancy. We identified the PD-relevant target stearoyl-coA desaturase: inhibiting monounsaturated FA synthesis reversed PD phenotypes. However, lipid degradation also generates FA pools. Here, we identify the rate-limiting lipase enzyme, LIPE, as a candidate target. Decreasing LIPE in human neural cells reduced αS inclusions. Patient αS triplication vs. corrected neurons had increased pSer129 and insoluble αS and decreased αS tetramer:monomer ratios. LIPE inhibition rescued all these and the abnormal unfolded protein response. LIPE inhibitors decreased pSer129 and restored tetramer:monomer equilibrium in αS E46K-expressing human neurons. LIPE reduction in vivo alleviated αS-induced dopaminergic neurodegeneration in Caenorhabditis elegans. Co-regulating FA synthesis and degradation proved additive in rescuing PD phenotypes, signifying co-targeting as a therapeutic strategy.
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Affiliation(s)
- Saranna Fanning
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
| | - Haley Cirka
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Jennifer L Thies
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Jooyoung Jeong
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Sarah M Niemi
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Joon Yoon
- Department of Biostatistics, The Harvard Chan School of Public Health, Boston, MA, 02115, USA
| | - Gary P H Ho
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | | | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Lei Liu
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Clary B Clish
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
| | - Kevin J Hodgetts
- Laboratory for Drug Discovery in Neuroscience, Department of Neurology, Brigham and Women's Hospital, Boston, MA, 02115, USA
| | - John N Hutchinson
- Department of Biostatistics, The Harvard Chan School of Public Health, Boston, MA, 02115, USA
| | - Christina R Muratore
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Guy A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Kim A Caldwell
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Dennis Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
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18
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Carnazza KE, Komer LE, Xie YX, Pineda A, Briano JA, Gao V, Na Y, Ramlall T, Buchman VL, Eliezer D, Sharma M, Burré J. Synaptic vesicle binding of α-synuclein is modulated by β- and γ-synucleins. Cell Rep 2022; 39:110675. [PMID: 35417693 PMCID: PMC9116446 DOI: 10.1016/j.celrep.2022.110675] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 01/23/2022] [Accepted: 03/22/2022] [Indexed: 12/16/2022] Open
Abstract
α-synuclein, β-synuclein, and γ-synuclein are abundantly expressed proteins in the vertebrate nervous system. α-synuclein functions in neurotransmitter release by binding to and clustering synaptic vesicles and chaperoning SNARE-complex assembly. Pathologically, aggregates originating from soluble pools of α-synuclein are deposited into Lewy bodies in Parkinson's disease and related synucleinopathies. The functions of β-synuclein and γ-synuclein in presynaptic terminals remain poorly studied. Using in vitro liposome binding studies, circular dichroism spectroscopy, immunoprecipitation, and fluorescence resonance energy transfer (FRET) experiments on isolated synaptic vesicles in combination with subcellular fractionation of brains from synuclein mouse models, we show that β-synuclein and γ-synuclein have a reduced affinity toward synaptic vesicles compared with α-synuclein, and that heteromerization of β-synuclein or γ-synuclein with α-synuclein results in reduced synaptic vesicle binding of α-synuclein in a concentration-dependent manner. Our data suggest that β-synuclein and γ-synuclein are modulators of synaptic vesicle binding of α-synuclein and thereby reduce α-synuclein's physiological activity at the neuronal synapse.
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Affiliation(s)
- Kathryn E Carnazza
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lauren E Komer
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Ying Xue Xie
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - André Pineda
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Juan Antonio Briano
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Virginia Gao
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Yoonmi Na
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Trudy Ramlall
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10021, USA
| | - Vladimir L Buchman
- School of Biosciences, Cardiff University, Cardiff CF103AX, UK; Belgorod State National Research University, 85 Pobedy Street, Belgorod, Belgorod 308015, Russian Federation
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10021, USA
| | - Manu Sharma
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jacqueline Burré
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY 10021, USA.
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19
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Brain region-specific susceptibility of Lewy body pathology in synucleinopathies is governed by α-synuclein conformations. Acta Neuropathol 2022; 143:453-469. [PMID: 35141810 PMCID: PMC8960659 DOI: 10.1007/s00401-022-02406-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/12/2022] [Accepted: 02/01/2022] [Indexed: 12/29/2022]
Abstract
The protein α-synuclein, a key player in Parkinson’s disease (PD) and other synucleinopathies, exists in different physiological conformations: cytosolic unfolded aggregation-prone monomers and helical aggregation-resistant multimers. It has been shown that familial PD-associated missense mutations within the α-synuclein gene destabilize the conformer equilibrium of physiologic α-synuclein in favor of unfolded monomers. Here, we characterized the relative levels of unfolded and helical forms of cytosolic α-synuclein in post-mortem human brain tissue and showed that the equilibrium of α-synuclein conformations is destabilized in sporadic PD and DLB patients. This disturbed equilibrium is decreased in a brain region-specific manner in patient samples pointing toward a possible “prion-like” propagation of the underlying pathology and forms distinct disease-specific patterns in the two different synucleinopathies. We are also able to show that a destabilization of multimers mechanistically leads to increased levels of insoluble, pathological α-synuclein, while pharmacological stabilization of multimers leads to a “prion-like” aggregation resistance. Together, our findings suggest that these disease-specific patterns of α-synuclein multimer destabilization in sporadic PD and DLB are caused by both regional neuronal vulnerability and “prion-like” aggregation transmission enabled by the destabilization of local endogenous α-synuclein protein.
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20
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Nuber S, Chung CY, Tardiff DF, Bechade PA, McCaffery TD, Shimanaka K, Choi J, Chang B, Raja W, Neves E, Burke C, Jiang X, Xu P, Khurana V, Dettmer U, Fanning S, Rhodes KJ, Selkoe DJ, Scannevin RH. A Brain-Penetrant Stearoyl-CoA Desaturase Inhibitor Reverses α-Synuclein Toxicity. Neurotherapeutics 2022; 19:1018-1036. [PMID: 35445353 PMCID: PMC9294123 DOI: 10.1007/s13311-022-01199-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2022] [Indexed: 12/01/2022] Open
Abstract
Increasing evidence has shown that Parkinson's disease (PD) impairs midbrain dopaminergic, cortical and other neuronal subtypes in large part due to the build-up of lipid- and vesicle-rich α-synuclein (αSyn) cytotoxic inclusions. We previously identified stearoyl-CoA desaturase (SCD) as a potential therapeutic target for synucleinopathies. A brain-penetrant SCD inhibitor, YTX-7739, was developed and has entered Phase 1 clinical trials. Here, we report the efficacy of YTX-7739 in reversing pathological αSyn phenotypes in various in vitro and in vivo PD models. In cell-based assays, YTX-7739 decreased αSyn-mediated neuronal death, reversed the abnormal membrane interaction of amplified E46K ("3K") αSyn, and prevented pathological phenotypes in A53T and αSyn triplication patient-derived neurospheres, including dysregulated fatty acid profiles and pS129 αSyn accumulation. In 3K PD-like mice, YTX-7739 crossed the blood-brain barrier, decreased unsaturated fatty acids, and prevented progressive motor deficits. Both YTX-7739 treatment and decreasing SCD activity through deletion of one copy of the SCD1 gene (SKO) restored the physiological αSyn tetramer-to-monomer ratio, dopaminergic integrity, and neuronal survival in 3K αSyn mice. YTX-7739 efficiently reduced pS129 + and PK-resistant αSyn in both human wild-type αSyn and 3K mutant mice similar to the level of 3K-SKO. Together, these data provide further validation of SCD as a PD therapeutic target and YTX-7739 as a clinical candidate for treating human α-synucleinopathies.
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Affiliation(s)
- Silke Nuber
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US.
| | - Chee Yeun Chung
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US.
| | | | - Pascal A Bechade
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
| | - Thomas D McCaffery
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
| | - Kazuma Shimanaka
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
| | - Jeonghoon Choi
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
| | - Belle Chang
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
- iNeuro Therapeutics, Cambridge, MA, 02116, US
| | - Waseem Raja
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
| | - Esther Neves
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
| | | | - Xin Jiang
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
| | - Ping Xu
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
| | - Vikram Khurana
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
| | - Saranna Fanning
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
| | - Kenneth J Rhodes
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
- Wave Life Sciences, 733 Concord Ave, Cambridge, MA, 02138, US
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women Hospital and Harvard Medical School, 60 Fenwood Rd, MA, 02115, Boston, US
| | - Robert H Scannevin
- Yumanity Therapeutics, 40 Guest Street, Boston, MA, 02135, US
- Verge Genomics, 2 Tower Pl, South San Francisco, CA, 94080, US
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21
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In vitro characterization of urea derivatives to inhibit alpha-synuclein early-stage aggregation. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Tardiff DF, Lucas M, Wrona I, Chang B, Chung CY, Le Bourdonnec B, Rhodes KJ, Scannevin RH. Non-clinical Pharmacology of YTX-7739: a Clinical Stage Stearoyl-CoA Desaturase Inhibitor Being Developed for Parkinson's Disease. Mol Neurobiol 2022; 59:2171-2189. [PMID: 35060064 PMCID: PMC9015998 DOI: 10.1007/s12035-021-02695-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/09/2021] [Indexed: 11/30/2022]
Abstract
Stearoyl-CoA desaturase (SCD) is a potential therapeutic target for Parkinson’s and related neurodegenerative diseases. SCD inhibition ameliorates neuronal toxicity caused by aberrant α-synuclein, a lipid-binding protein implicated in Parkinson’s disease. Its inhibition depletes monounsaturated fatty acids, which may modulate α-synuclein conformations and membrane interactions. Herein, we characterize the pharmacokinetic and pharmacodynamic properties of YTX-7739, a clinical-stage SCD inhibitor. Administration of YTX-7739 to rats and monkeys for 15 days caused a dose-dependent increase in YTX-7739 concentrations that were well-tolerated and associated with concentration-dependent reductions in the fatty acid desaturation index (FADI), the ratio of monounsaturated to saturated fatty acids. An approximate 50% maximal reduction in the carbon-16 desaturation index was observed in the brain, with comparable responses in the plasma and skin. A study with a diet supplemented in SCD products indicates that changes in brain C16 desaturation were due to local SCD inhibition, rather than to changes in systemic fatty acids that reach the brain. Assessment of pharmacodynamic response onset and reversibility kinetics indicated that approximately 7 days of dosing were required to achieve maximal responses, which persisted for at least 2 days after cessation of dosing. YTX-7739 thus achieved sufficient concentrations in the brain to inhibit SCD and produce pharmacodynamic responses that were well-tolerated in rats and monkeys. These results provide a framework for evaluating YTX-7739 pharmacology clinically as a disease-modifying therapy to treat synucleinopathies.
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Affiliation(s)
- Daniel F Tardiff
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.
| | - Matthew Lucas
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.,Black Diamond Therapeutics, 1 Main Street, Cambridge, MA, 02142, USA
| | - Iwona Wrona
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.,Black Diamond Therapeutics, 1 Main Street, Cambridge, MA, 02142, USA
| | - Belle Chang
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.,iNeuro Therapeutics, 325 Vassar Street, Cambridge, MA, 02139, USA
| | - Chee Yeun Chung
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA
| | - Bertrand Le Bourdonnec
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.,Deciphera Pharmaceuticals, 200 Smith St, Waltham, MA, 02451, USA
| | - Kenneth J Rhodes
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.,Pfizer Rare Disease Research Unit, 1 Portland Street, Cambridge, MA, 02139, USA
| | - Robert H Scannevin
- Yumanity Therapeutics, 40 Guest Street, Suite 4410, Boston, MA, 02135, USA.,Verge Genomics, 2 Tower Pl, San Francisco, CA, 94080, USA
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23
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Lysophosphatidylcholine acyltransferase 1 promotes pathology and toxicity in two distinct cell-based alpha-synuclein models. Neurosci Lett 2022; 772:136491. [DOI: 10.1016/j.neulet.2022.136491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/22/2022]
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24
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Xu L, Bhattacharya S, Thompson D. Predictive Modeling of Neurotoxic α-Synuclein Polymorphs. Methods Mol Biol 2022; 2340:379-399. [PMID: 35167083 DOI: 10.1007/978-1-0716-1546-1_17] [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] [Indexed: 06/14/2023]
Abstract
Assembly of monomeric α-synuclein (αS) into aggregation-resistant helically folded tetramers and related multimers is a key target for Parkinson's disease (PD). Protein dynamics hampers experimental characterization of the polymorphism of these structures and so computational modeling and simulation is providing a complementary approach to obtain high-resolution structural information on the assembly of αS and interactions with biological surfaces. These computational techniques are particularly valuable for intrinsically disordered proteins (IDPs) and short-lived peptide and protein assemblies with as yet undetermined 3D structures. Experimental observables such as NMR J-coupling constants and chemical shifts can be predicted directly from simulation data, and compared with available experimental data to generate the most physically realistic atomic-resolution structure. For appropriately validated and benchmarked computational models, macroscopic aggregation properties can be related to the calculated thermodynamic properties at an atomic level. In this chapter, we describe a useful protocol for designing helical αS multimers, especially tetramers, and scanning the peptide-membrane interface for cell-bound αS tetramers. These computationally modeled structures are validated by comparison with the range of available known experimental parameters at time of writing in early 2020, and used to generate predictive design rules to motivate and guide experiments.
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Affiliation(s)
- Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland.
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25
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Tripathi A, Fanning S, Dettmer U. Lipotoxicity Downstream of α-Synuclein Imbalance: A Relevant Pathomechanism in Synucleinopathies? Biomolecules 2021; 12:40. [PMID: 35053188 PMCID: PMC8774010 DOI: 10.3390/biom12010040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/16/2021] [Accepted: 12/21/2021] [Indexed: 12/15/2022] Open
Abstract
Neuronal loss in Parkinson's disease and related brain diseases has been firmly linked to the abundant neuronal protein α-synuclein (αS). However, we have gained surprisingly little insight into how exactly αS exerts toxicity in these diseases. Hypotheses of proteotoxicity, disturbed vesicle trafficking, mitochondrial dysfunction and other toxicity mechanisms have been proposed, and it seems possible that a combination of different mechanisms may drive pathology. A toxicity mechanism that has caught increased attention in the recent years is αS-related lipotoxicity. Lipotoxicity typically occurs in a cell when fatty acids exceed the metabolic needs, triggering a flux into harmful pathways of non-oxidative metabolism. Genetic and experimental approaches have revealed a significant overlap between lipid storage disorders, most notably Gaucher's disease, and synucleinopathies. There is accumulating evidence for lipid aberrations causing synuclein misfolding as well as for αS excess and misfolding causing lipid aberration. Does that mean the key problem in synucleinopathies is lipotoxicity, the accumulation of harmful lipid species or alteration in lipid equilibrium? Here, we review the existing literature in an attempt to get closer to an answer.
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Affiliation(s)
- Arati Tripathi
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | | | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
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26
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Girard V, Jollivet F, Knittelfelder O, Celle M, Arsac JN, Chatelain G, Van den Brink DM, Baron T, Shevchenko A, Kühnlein RP, Davoust N, Mollereau B. Abnormal accumulation of lipid droplets in neurons induces the conversion of alpha-Synuclein to proteolytic resistant forms in a Drosophila model of Parkinson's disease. PLoS Genet 2021; 17:e1009921. [PMID: 34788284 PMCID: PMC8635402 DOI: 10.1371/journal.pgen.1009921] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 12/01/2021] [Accepted: 11/02/2021] [Indexed: 11/18/2022] Open
Abstract
Parkinson’s disease (PD) is a neurodegenerative disorder characterized by alpha-synuclein (αSyn) aggregation and associated with abnormalities in lipid metabolism. The accumulation of lipids in cytoplasmic organelles called lipid droplets (LDs) was observed in cellular models of PD. To investigate the pathophysiological consequences of interactions between αSyn and proteins that regulate the homeostasis of LDs, we used a transgenic Drosophila model of PD, in which human αSyn is specifically expressed in photoreceptor neurons. We first found that overexpression of the LD-coating proteins Perilipin 1 or 2 (dPlin1/2), which limit the access of lipases to LDs, markedly increased triacylglyclerol (TG) loaded LDs in neurons. However, dPlin-induced-LDs in neurons are independent of lipid anabolic (diacylglycerol acyltransferase 1/midway, fatty acid transport protein/dFatp) and catabolic (brummer TG lipase) enzymes, indicating that alternative mechanisms regulate neuronal LD homeostasis. Interestingly, the accumulation of LDs induced by various LD proteins (dPlin1, dPlin2, CG7900 or KlarsichtLD-BD) was synergistically amplified by the co-expression of αSyn, which localized to LDs in both Drosophila photoreceptor neurons and in human neuroblastoma cells. Finally, the accumulation of LDs increased the resistance of αSyn to proteolytic digestion, a characteristic of αSyn aggregation in human neurons. We propose that αSyn cooperates with LD proteins to inhibit lipolysis and that binding of αSyn to LDs contributes to the pathogenic misfolding and aggregation of αSyn in neurons. Parkinson’s disease (PD) is a neurodegenerative disease characterized by the neurotoxic aggregation of the alpha-synuclein (αSyn) protein. Cellular models of the disease are also associated with an abnormal fat storage in the form of lipid droplets (LDs). However, in which cells, neuron or glial cells, LDs accumulate in the organism remains unknown. To understand the relationship between αSyn and the accumulation of LDs, we used a Drosophila (fruit fly) model of PD. We found that, in the presence of a protein that coats LDs, perilipin, LDs accumulate in photoreceptor neurons of the fly. Interestingly, the accumulation of LDs induced by perilipin or other LD-coating proteins was enhanced in the presence of αSyn. Using human neuronal cell lines and the fly, we could show that LD-coating and αSyn proteins localize at the surface of LDs. Finally, we observed that the process of αSyn aggregation was enhanced in the presence of LDs by using a biochemical approach. We thus propose that the association of αSyn with LDs could contribute to αSyn aggregation and progression of the pathology.
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Affiliation(s)
- Victor Girard
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Florence Jollivet
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Oskar Knittelfelder
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Marion Celle
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Jean-Noel Arsac
- Neurodegenerative Disease Unit; French Agency for Food, Environmental and Occupational Health & Safety Laboratory (Anses) of Lyon, University of Lyon, Lyon, France
| | - Gilles Chatelain
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Daan M. Van den Brink
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
- Plant Systems Physiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Thierry Baron
- Neurodegenerative Disease Unit; French Agency for Food, Environmental and Occupational Health & Safety Laboratory (Anses) of Lyon, University of Lyon, Lyon, France
| | - Andrej Shevchenko
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ronald P. Kühnlein
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
- Field of Excellence BioHealth—University of Graz, Graz, Austria
| | - Nathalie Davoust
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
- * E-mail: (ND); (BM)
| | - Bertrand Mollereau
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
- * E-mail: (ND); (BM)
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27
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Dias C, Nita E, Faktor J, Tynan AC, Hernychova L, Vojtesek B, Nylandsted J, Hupp TR, Kunath T, Ball KL. CHIP-dependent regulation of the actin cytoskeleton is linked to neuronal cell membrane integrity. iScience 2021; 24:102878. [PMID: 34401662 PMCID: PMC8350547 DOI: 10.1016/j.isci.2021.102878] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/13/2021] [Accepted: 07/15/2021] [Indexed: 12/12/2022] Open
Abstract
CHIP is an E3-ubiquitin ligase that contributes to healthy aging and has been characterized as neuroprotective. To elucidate dominant CHIP-dependent changes in protein steady-state levels in a patient-derived human neuronal model, CHIP function was ablated using gene-editing and an unbiased proteomic analysis conducted to compare knock-out and wild-type isogenic induced pluripotent stem cell (iPSC)-derived cortical neurons. Rather than a broad effect on protein homeostasis, loss of CHIP function impacted on a focused cohort of proteins from actin cytoskeleton signaling and membrane integrity networks. In support of the proteomics, CHIP knockout cells had enhanced sensitivity to induced membrane damage. We conclude that the major readout of CHIP function in cortical neurons derived from iPSC of a patient with elevate α-synuclein, Parkinson's disease and dementia, is the modulation of substrates involved in maintaining cellular "health". Thus, regulation of the actin cytoskeletal and membrane integrity likely contributes to the neuroprotective function(s) of CHIP.
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Affiliation(s)
- Catarina Dias
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, The University of Edinburgh, Edinburgh EH16 4UU, UK
| | - Erisa Nita
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Jakub Faktor
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
- University of Gdansk, International Centre for Cancer Vaccine Science, 80-822 Gdansk, Poland
| | - Ailish C. Tynan
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Lenka Hernychova
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Borivoj Vojtesek
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Jesper Nylandsted
- Membrane Integrity Group, Danish Cancer Society Research Center, Strandboulevarden 49, 2100, Copenhagen, Denmark
| | - Ted R. Hupp
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- University of Gdansk, International Centre for Cancer Vaccine Science, 80-822 Gdansk, Poland
| | - Tilo Kunath
- Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, The University of Edinburgh, Edinburgh EH16 4UU, UK
| | - Kathryn L. Ball
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
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28
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Kayed R, Dettmer U, Lesné SE. Soluble endogenous oligomeric α-synuclein species in neurodegenerative diseases: Expression, spreading, and cross-talk. JOURNAL OF PARKINSON'S DISEASE 2021; 10:791-818. [PMID: 32508330 PMCID: PMC7458533 DOI: 10.3233/jpd-201965] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
There is growing recognition in the field of neurodegenerative diseases that mixed proteinopathies are occurring at greater frequency than originally thought. This is particularly true for three amyloid proteins defining most of these neurological disorders, amyloid-beta (Aβ), tau, and alpha-synuclein (αSyn). The co-existence and often co-localization of aggregated forms of these proteins has led to the emergence of concepts positing molecular interactions and cross-seeding between Aβ, tau, and αSyn aggregates. Amongst this trio, αSyn has received particular attention in this context during recent years due to its ability to modulate Aβ and tau aggregation in vivo, to interact at a molecular level with Aβ and tau in vivo and to cross-seed tau in mice. Here we provide a comprehensive, critical, and accessible review about the expression, role and nature of endogenous soluble αSyn oligomers because of recent developments in the understanding of αSyn multimerization, misfolding, aggregation, cross-talk, spreading and cross-seeding in neurodegenerative disorders, including Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, Alzheimer's disease, and Huntington's disease. We will also discuss our current understanding about the relative toxicity of endogenous αSyn oligomers in vivo and in vitro, and introduce potential opportunities to counter their deleterious effects.
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Affiliation(s)
- Rakez Kayed
- Departments of Neurology & Neuroscience & Cell Biology & Anatomy, University of Texas Medical Branch Galveston, Galveston, TX, USA,George and Cynthia Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch Galveston, Galveston, TX, USA
| | - Ulf Dettmer
- Department of Neurology, Harvard Medical School, Boston, MA, USA,Ann Romney Center for Neurologic Diseases, Harvard Medical School, Boston, MA, USA
| | - Sylvain E. Lesné
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA,Institute of Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA,Correspondence to: Sylvain E. Lesné, PhD, University of Minnesota, Wallin Medical Biosciences Building (Room 4-114), 2101 Sixth Street SE, CDC 2641, Minneapolis, MN 55414, USA. Tel.: +1 612 626 8341; E-mail: ; Website: https://lesnelab.org
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29
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SCD Inhibition Protects from α-Synuclein-Induced Neurotoxicity But Is Toxic to Early Neuron Cultures. eNeuro 2021; 8:ENEURO.0166-21.2021. [PMID: 34301719 PMCID: PMC8387157 DOI: 10.1523/eneuro.0166-21.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/08/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022] Open
Abstract
Here, we report the independent discovery and validation of stearoyl-CoA desaturase (SCD) as a modulator of α-synuclein (αSyn)-induced pathology and toxicity in cell-based Parkinson’s disease (PD) models. We identified SCD as top altered gene from transcriptional profiling in primary neurons exogenously expressing αSyn with the amplified familial PD mutation 3K. Thus, we sought to further explore SCD as a therapeutic target in neurodegeneration. We report that SCD inhibitors are toxic to early human and rat neuron cultures while displaying minimal toxicity to late cultures. The fatty acid product of SCD, oleic acid (OLA), fully rescues this toxicity in early cultures, suggesting on-target toxicity. Furthermore, SCD inhibition rescues αSyn 3K-induced toxicity in late primary neurons. We also confirm that SCD inhibitors reduce formation of αSyn accumulations, while OLA increases these accumulations in an αSyn 3K neuroblastoma model. However, we identify a caveat with this model where αSyn 3K levels can be suppressed by high SCD inhibitor concentrations, obscuring true effect size. Further, we show that both SCD1 or SCD5 knock-down reduce αSyn 3K accumulations and toxicity, making both a putative drug target. Overall, we confirm key findings of published data on SCD inhibition and its benefits in αSyn accumulation and stress models. The differential neurotoxicity induced by SCD inhibition based on neuron culture age must be accounted for when researching SCD in neuron models and has potential clinical implications. Lastly, our gene profiling studies also revealed novel putative genes connected to αSyn neurotoxicity that are worth further study.
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30
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Oliveira LMA, Gasser T, Edwards R, Zweckstetter M, Melki R, Stefanis L, Lashuel HA, Sulzer D, Vekrellis K, Halliday GM, Tomlinson JJ, Schlossmacher M, Jensen PH, Schulze-Hentrich J, Riess O, Hirst WD, El-Agnaf O, Mollenhauer B, Lansbury P, Outeiro TF. Alpha-synuclein research: defining strategic moves in the battle against Parkinson's disease. NPJ Parkinsons Dis 2021; 7:65. [PMID: 34312398 PMCID: PMC8313662 DOI: 10.1038/s41531-021-00203-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 05/14/2021] [Indexed: 12/13/2022] Open
Abstract
With the advent of the genetic era in Parkinson's disease (PD) research in 1997, α-synuclein was identified as an important player in a complex neurodegenerative disease that affects >10 million people worldwide. PD has been estimated to have an economic impact of $51.9 billion in the US alone. Since the initial association with PD, hundreds of researchers have contributed to elucidating the functions of α-synuclein in normal and pathological states, and these remain critical areas for continued research. With this position paper the authors strive to achieve two goals: first, to succinctly summarize the critical features that define α-synuclein's varied roles, as they are known today; and second, to identify the most pressing knowledge gaps and delineate a multipronged strategy for future research with the goal of enabling therapies to stop or slow disease progression in PD.
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Affiliation(s)
- Luis M A Oliveira
- The Michael J. Fox Foundation for Parkinson's Research, New York, NY, USA.
| | - Thomas Gasser
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Robert Edwards
- Departments of Neurology and Physiology, UCSF School of Medicine, San Francisco, CA, USA
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ronald Melki
- Institut François Jacob, MIRCen, CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-aux-Roses, France
| | - Leonidas Stefanis
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- First Department of Neurology, Medical School of the National and Kapodistrian University of Athens, Athens, Greece
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Faculty of Life Sciences, EPFL, Lausanne, Switzerland
| | - David Sulzer
- Department of Psychiatry, Neurology, Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA
| | - Kostas Vekrellis
- Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Glenda M Halliday
- University of Sydney, Brain and Mind Centre and Faculty of Medicine and Health, School of Medical Sciences, Sydney, NSW, Australia
| | - Julianna J Tomlinson
- Neuroscience Program, The Ottawa Hospital, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
| | - Michael Schlossmacher
- Neuroscience Program, The Ottawa Hospital, Ottawa, ON, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada
- Division of Neurology, The Ottawa Hospital, Ottawa, ON, Canada
| | - Poul Henning Jensen
- Aarhus University, Department of Biomedicine & DANDRITE, Danish Research Institute of Translational Neuroscience, Aarhus, Denmark
| | - Julia Schulze-Hentrich
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Warren D Hirst
- Neurodegenerative Diseases Research Unit, Biogen, Cambridge, MA, USA
| | - Omar El-Agnaf
- Neurological Disorder Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Brit Mollenhauer
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Paracelsus-Elena-Klinik, Kassel, Germany
| | | | - Tiago F Outeiro
- German Center for Neurodegenerative Diseases (DZNE), Göttingen, Germany.
- Department of Experimental Neurodegeneration, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.
- Max Planck Institute for Experimental Medicine, Göttingen, Germany.
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle, UK.
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31
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Kim TE, Newman AJ, Imberdis T, Brontesi L, Tripathi A, Ramalingam N, Fanning S, Selkoe D, Dettmer U. Excess membrane binding of monomeric alpha-, beta-, and gamma-synuclein is invariably associated with inclusion formation and toxicity. Hum Mol Genet 2021; 30:2332-2346. [PMID: 34254125 PMCID: PMC8600006 DOI: 10.1093/hmg/ddab188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/15/2021] [Accepted: 07/05/2021] [Indexed: 11/27/2022] Open
Abstract
α-Synuclein (αS) has been well-documented to play a role in human synucleinopathies such as Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). First, the lesions found in PD/DLB brains—Lewy bodies and Lewy neurites—are rich in aggregated αS. Second, genetic evidence links missense mutations and increased αS expression to familial forms of PD/DLB. Third, toxicity and cellular stress can be caused by αS under certain experimental conditions. In contrast, the homologs β-synuclein (βS) and γ-synuclein (γS) are not typically found in Lewy bodies/neurites, have not been clearly linked to brain diseases and have been largely non-toxic in experimental settings. In αS, the so-called non-amyloid-β component of plaques (NAC) domain, constituting amino acids 61–95, has been identified to be critical for aggregation in vitro. This domain is partially absent in βS and only incompletely conserved in γS, which could explain why both homologs do not cause disease. However, αS in vitro aggregation and cellular toxicity have not been firmly linked experimentally, and it has been proposed that excess αS membrane binding is sufficient to induce neurotoxicity. Indeed, recent characterizations of Lewy bodies have highlighted the accumulation of lipids and membranous organelles, raising the possibility that βS and γS could also become neurotoxic if they were more prone to membrane/lipid binding. Here, we increased βS and γS membrane affinity by strategic point mutations and demonstrate that these proteins behave like membrane-associated monomers, are cytotoxic and form round cytoplasmic inclusions that can be prevented by inhibiting stearoyl-CoA desaturase.
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Affiliation(s)
- Tae-Eun Kim
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Andrew J Newman
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Thibaut Imberdis
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Lisa Brontesi
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Arati Tripathi
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Saranna Fanning
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Dennis Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115 USA
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Altered conformation of α-synuclein drives dysfunction of synaptic vesicles in a synaptosomal model of Parkinson's disease. Cell Rep 2021; 36:109333. [PMID: 34233191 PMCID: PMC8552450 DOI: 10.1016/j.celrep.2021.109333] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/30/2020] [Accepted: 06/10/2021] [Indexed: 11/23/2022] Open
Abstract
While misfolding of alpha-synuclein (αSyn) is central to the pathogenesis of Parkinson's disease (PD), fundamental questions about its structure and function at the synapse remain unanswered. We examine synaptosomes from non-transgenic and transgenic mice expressing wild-type human αSyn, the E46K fPD-causing mutation, or an amplified form of E46K ("3K"). Synaptosomes from mice expressing the 3K mutant show reduced Ca2+-dependent vesicle exocytosis, altered synaptic vesicle ultrastructure, decreased SNARE complexes, and abnormal levels of certain synaptic proteins. With our intra-synaptosomal nuclear magnetic resonance (NMR) method, we reveal that WT αSyn participates in heterogeneous interactions with synaptic components dependent on endogenous αSyn and synaptosomal integrity. The 3K mutation markedly alters these interactions. The synaptic microenvironment is necessary for αSyn to reach its native conformations and establish a physiological interaction network. Its inability to populate diverse conformational ensembles likely represents an early step in αSyn dysfunction that contributes to the synaptotoxicity observed in synucleinopathies.
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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: 8.3] [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.
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Crowded organelles, lipid accumulation, and abnormal membrane tubulation in cellular models of enhanced α-synuclein membrane interaction. Brain Res 2021; 1758:147349. [PMID: 33571519 DOI: 10.1016/j.brainres.2021.147349] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/13/2021] [Accepted: 02/02/2021] [Indexed: 11/24/2022]
Abstract
Previous work from our group showed that certain engineered missense mutations to the α-synuclein (αS) KTKEGV repeat motifs abrogate the protein's ability to form native multimers. The resultant excess monomers accumulate in lipid-membrane-rich inclusions associated with neurotoxicity exceeding that of natural familial Parkinson's disease mutants such as E46K. We presented an initial characterization of the lipid-rich inclusions and found similarities to the αS- and vesicle-rich inclusions that form in baker's yeast when αS is expressed. We also discussed, with some caution, a possible role of membrane-rich inclusions as precursors to filamentous Lewy bodies, the widely accepted hallmark pathology of Parkinson's disease and other synucleinopathies. In the meantime, advances in the microscopic characterization of Lewy bodies have highlighted the presence of crowded organelles and lipid membranes in addition to αS accumulation. This prompted us to revisit the αS inclusions caused by our repeat motif variants in neuroblastoma cells. In addition to our previous characterization, we found that these inclusions can often be seen by brightfield microscopy, overlap with endogenous vesicle markers in immunofluorescence experiments, stain positive for lipid dyes, and can be found to be closely associated with mitochondria. We also observed abnormal tubulation of membranes, which was subtle in inducible lines and pronounced in cells that transiently expressed high amounts of the highly disruptive KTKEGV motif mutant "KLKEGV". Membrane tubulation had been reported before as an αS activity in reductionist systems. Our in-cellulo demonstration now suggests that this mechanism could possibly be a relevant aspect of aberrant αS behavior in cells.
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Román-Vendrell C, Medeiros AT, Sanderson JB, Jiang H, Bartels T, Morgan JR. Effects of Excess Brain-Derived Human α-Synuclein on Synaptic Vesicle Trafficking. Front Neurosci 2021; 15:639414. [PMID: 33613189 PMCID: PMC7890186 DOI: 10.3389/fnins.2021.639414] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/18/2021] [Indexed: 11/13/2022] Open
Abstract
α-Synuclein is a presynaptic protein that regulates synaptic vesicle trafficking under physiological conditions. However, in several neurodegenerative diseases, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, α-synuclein accumulates throughout the neuron, including at synapses, leading to altered synaptic function, neurotoxicity, and motor, cognitive, and autonomic dysfunction. Neurons typically contain both monomeric and multimeric forms of α-synuclein, and it is generally accepted that disrupting the balance between them promotes aggregation and neurotoxicity. However, it remains unclear how distinct molecular species of α-synuclein affect synapses where α-synuclein is normally expressed. Using the lamprey reticulospinal synapse model, we previously showed that acute introduction of excess recombinant monomeric or dimeric α-synuclein impaired distinct stages of clathrin-mediated synaptic vesicle endocytosis, leading to a loss of synaptic vesicles. Here, we expand this knowledge by investigating the effects of native, physiological α-synuclein isolated from the brain of a neuropathologically normal human subject, which comprised predominantly helically folded multimeric α-synuclein with a minor component of monomeric α-synuclein. After acute introduction of excess brain-derived human α-synuclein, there was a moderate reduction in the synaptic vesicle cluster and an increase in the number of large, atypical vesicles called "cisternae." In addition, brain-derived α-synuclein increased synaptic vesicle and cisternae sizes and induced atypical fusion/fission events at the active zone. In contrast to monomeric or dimeric α-synuclein, the brain-derived multimeric α-synuclein did not appear to alter clathrin-mediated synaptic vesicle endocytosis. Taken together, these data suggest that excess brain-derived human α-synuclein impairs intracellular vesicle trafficking and further corroborate the idea that different molecular species of α-synuclein produce distinct trafficking defects at synapses. These findings provide insights into the mechanisms by which excess α-synuclein contributes to synaptic deficits and disease phenotypes.
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Affiliation(s)
- Cristina Román-Vendrell
- The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Audrey T Medeiros
- The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, United States
| | - John B Sanderson
- Harvard Medical School, Brigham and Women's Hospital, Boston, MA, United States
| | - Haiyang Jiang
- Harvard Medical School, Brigham and Women's Hospital, Boston, MA, United States
| | - Tim Bartels
- UK Dementia Research Institute, University College London, London, United Kingdom
| | - Jennifer R Morgan
- The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, United States
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Plasma membrane integrity in health and disease: significance and therapeutic potential. Cell Discov 2021; 7:4. [PMID: 33462191 PMCID: PMC7813858 DOI: 10.1038/s41421-020-00233-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/23/2020] [Indexed: 12/13/2022] Open
Abstract
Maintenance of plasma membrane integrity is essential for normal cell viability and function. Thus, robust membrane repair mechanisms have evolved to counteract the eminent threat of a torn plasma membrane. Different repair mechanisms and the bio-physical parameters required for efficient repair are now emerging from different research groups. However, less is known about when these mechanisms come into play. This review focuses on the existence of membrane disruptions and repair mechanisms in both physiological and pathological conditions, and across multiple cell types, albeit to different degrees. Fundamentally, irrespective of the source of membrane disruption, aberrant calcium influx is the common stimulus that activates the membrane repair response. Inadequate repair responses can tip the balance between physiology and pathology, highlighting the significance of plasma membrane integrity. For example, an over-activated repair response can promote cancer invasion, while the inability to efficiently repair membrane can drive neurodegeneration and muscular dystrophies. The interdisciplinary view explored here emphasises the widespread potential of targeting plasma membrane repair mechanisms for therapeutic purposes.
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Ramalingam N, Dettmer U. Temperature is a key determinant of alpha- and beta-synuclein membrane interactions in neurons. J Biol Chem 2021; 296:100271. [PMID: 33428933 PMCID: PMC7949061 DOI: 10.1016/j.jbc.2021.100271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/02/2023] Open
Abstract
Aggregation of α-synuclein (αS) leads to the hallmark neuropathology of Parkinson's disease (PD) and related synucleinopathies. αS has been described to exist in both cytosolic and membrane-associated forms, the relative abundance of which has remained unsettled. To study αS under the most relevant conditions by a quantitative method, we cultured and matured rodent primary cortical neurons for >17 days and determined αS cytosol:membrane distribution via centrifugation-free sequential extractions based on the weak ionic detergent digitonin. We noticed that at lower temperatures (4 °C or room temperature), αS was largely membrane-associated. At 37 °C, however, αS solubility was markedly increased. In contrast, the extraction of control proteins (GAPDH, cytosolic; calnexin, membrane) was not affected by temperature. When we compared the relative distribution of the synuclein homologs αS and β-synuclein (βS) under various conditions that differed in temperature and digitonin concentration (200-1200 μg/ml), we consistently found αS to be more membrane-associated than βS. Both proteins, however, exhibited temperature-dependent membrane binding. Under the most relevant conditions (37 °C and 800 μg/ml digitonin, i.e., the lowest digitonin concentration that extracted cytosolic GAPDH to near completion), cytosolic distribution was 49.8% ± 9.0% for αS and 63.6% ± 6.6% for βS. PD-linked αS A30P was found to be largely cytosolic, confirming previous studies that had used different methods. Our work highlights the dynamic nature of cellular synuclein behavior and has important implications for protein-biochemical and cell-biological studies of αS proteostasis, such as testing the effects of genetic and pharmacological manipulations.
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Affiliation(s)
- Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
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Ho GPH, Ramalingam N, Imberdis T, Wilkie EC, Dettmer U, Selkoe DJ. Upregulation of Cellular Palmitoylation Mitigates α-Synuclein Accumulation and Neurotoxicity. Mov Disord 2020; 36:348-359. [PMID: 33103814 DOI: 10.1002/mds.28346] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 09/29/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Synucleinopathies, including Parkinson's disease (PD), are characterized by α-synuclein (αS) cytoplasmic inclusions. αS-dependent vesicle-trafficking defects are important in PD pathogenesis, but their mechanisms are not well understood. Protein palmitoylation, post-translational addition of the fatty acid palmitate to cysteines, promotes trafficking by anchoring specific proteins to the vesicle membrane. αS itself cannot be palmitoylated as it lacks cysteines, but it binds to membranes, where palmitoylation occurs, via an amphipathic helix. We hypothesized that abnormal αS membrane-binding impairs trafficking by disrupting palmitoylation. Accordingly, we investigated the therapeutic potential of increasing cellular palmitoylation. OBJECTIVES We asked whether upregulating palmitoylation by inhibiting the depalmitoylase acyl-protein-thioesterase-1 (APT1) ameliorates pathologic αS-mediated cellular phenotypes and sought to identify the mechanism. METHODS Using human neuroblastoma cells, rat neurons, and iPSC-derived PD patient neurons, we examined the effects of pharmacologic and genetic downregulation of APT1 on αS-associated phenotypes. RESULTS APT1 inhibition or knockdown decreased αS cytoplasmic inclusions, reduced αS serine-129 phosphorylation (a PD neuropathological marker), and protected against αS-dependent neurotoxicity. We identified the APT1 substrate microtubule-associated-protein-6 (MAP6), which binds to vesicles in a palmitoylation-dependent manner, as a key mediator of these effects. Mechanistically, we found that pathologic αS accelerated palmitate turnover on MAP6, suggesting that APT1 inhibition corrects a pathological αS-dependent palmitoylation deficit. We confirmed the disease relevance of this mechanism by demonstrating decreased MAP6 palmitoylation in neurons from αS gene triplication patients. CONCLUSIONS Our findings demonstrate a novel link between the fundamental process of palmitoylation and αS pathophysiology. Upregulating palmitoylation represents an unexplored therapeutic strategy for synucleinopathies. © 2020 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Gary P H Ho
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Thibaut Imberdis
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Erin C Wilkie
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Nuber S, Nam AY, Rajsombath MM, Cirka H, Hronowski X, Wang J, Hodgetts K, Kalinichenko LS, Müller CP, Lambrecht V, Winkler J, Weihofen A, Imberdis T, Dettmer U, Fanning S, Selkoe DJ. A Stearoyl-Coenzyme A Desaturase Inhibitor Prevents Multiple Parkinson Disease Phenotypes in α-Synuclein Mice. Ann Neurol 2020; 89:74-90. [PMID: 32996158 PMCID: PMC7756464 DOI: 10.1002/ana.25920] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 12/20/2022]
Abstract
Objective Parkinson disease (PD) has useful symptomatic treatments that do not slow the neurodegenerative process, and no significant disease‐modifying treatments are approved. A key therapeutic target in PD is α‐synuclein (αS), which is both genetically implicated and accumulates in Lewy bodies rich in vesicles and other lipid membranes. Reestablishing αS homeostasis is a central goal in PD. Based on previous lipidomic analyses, we conducted a mouse trial of a stearoyl–coenzyme A desaturase (SCD) inhibitor (“5b”) that prevented αS‐positive vesicular inclusions and cytotoxicity in cultured human neurons. Methods Oral dosing and brain activity of 5b were established in nontransgenic mice. 5b in drinking water was given to mice expressing wild‐type human αS (WT) or an amplified familial PD αS mutation (E35K + E46K + E61K ["3K"]) beginning near the onset of nigral and cortical neurodegeneration and the robust PD‐like motor syndrome in 3K. Motor phenotypes, brain cytopathology, and SCD‐related lipid changes were quantified in 5b‐ versus placebo‐treated mice. Outcomes were compared to effects of crossing 3K to SCD1−/− mice. Results 5b treatment reduced αS hyperphosphorylation in E46K‐expressing human neurons, in 3K neural cultures, and in both WT and 3K αS mice. 5b prevented subtle gait deficits in WT αS mice and the PD‐like resting tremor and progressive motor decline of 3K αS mice. 5b also increased αS tetramers and reduced proteinase K‐resistant lipid‐rich aggregates. Similar benefits accrued from genetically deleting 1 SCD allele, providing target validation. Interpretation Prolonged reduction of brain SCD activity prevented PD‐like neuropathology in multiple PD models. Thus, an orally available SCD inhibitor potently ameliorates PD phenotypes, positioning this approach to treat human α‐synucleinopathies. ANN NEUROL 2021;89:74–90
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Affiliation(s)
- Silke Nuber
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Alice Y Nam
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Molly M Rajsombath
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Haley Cirka
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Junmin Wang
- Chemical Biology & Proteomics, Biogen, Cambridge, MA, USA
| | - Kevin Hodgetts
- Laboratory for Drug Discovery in Neurodegeneration, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Liubov S Kalinichenko
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Christian P Müller
- Department of Psychiatry and Psychotherapy, University Clinic, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Vera Lambrecht
- Division of Molecular Neurology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Jürgen Winkler
- Division of Molecular Neurology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany
| | - Andreas Weihofen
- Neurodegenerative Diseases Research Unit, Biogen, Cambridge, MA, USA
| | - Thibaut Imberdis
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Saranna Fanning
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
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Gilmozzi V, Gentile G, Castelo Rueda MP, Hicks AA, Pramstaller PP, Zanon A, Lévesque M, Pichler I. Interaction of Alpha-Synuclein With Lipids: Mitochondrial Cardiolipin as a Critical Player in the Pathogenesis of Parkinson's Disease. Front Neurosci 2020; 14:578993. [PMID: 33122994 PMCID: PMC7573567 DOI: 10.3389/fnins.2020.578993] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/10/2020] [Indexed: 12/31/2022] Open
Abstract
Alpha-Synuclein (α-Syn) is a central protein in the pathogenesis of synucleinopathies, a group of neurodegenerative disorders including Parkinson’s disease (PD). Although its role in neurotransmission is well established, the precise role of this protein in disease pathogenesis is still not fully understood. It is, however, widely regarded to be associated with the misfolding and accumulation of toxic intracellular aggregates. In fact, α-Syn is the most abundant protein component of Lewy bodies and Lewy neurites, which are also characterized by a high lipid content. Lipids, the main constituents of cellular membranes, have been implicated in many aspects of PD-related processes. α-Syn interacts with membrane phospholipids and free fatty acids via its N-terminal domain, and altered lipid-protein complexes might enhance both its binding to synaptic and mitochondrial membranes and its oligomerization. Several studies have highlighted a specific interaction of α-Syn with the phospholipid cardiolipin (CL), a major constituent of mitochondrial membranes. By interacting with CL, α-Syn is able to disrupt mitochondrial membrane integrity, leading to mitochondrial dysfunction. Additionally, externalized CL is able to facilitate the refolding of toxic α-Syn species at the outer mitochondrial membrane. In this review, we discuss how α-Syn/lipid interactions, in particular the α-Syn/CL interaction at the mitochondrial membrane, may affect α-Syn aggregation and mitochondrial dysfunction and may thus represent an important mechanism in the pathogenesis of PD.
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Affiliation(s)
- Valentina Gilmozzi
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy
| | - Giovanna Gentile
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy
| | | | - Andrew A Hicks
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy
| | - Peter P Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy.,Department of Neurology, University of Lübeck, Lübeck, Germany
| | - Alessandra Zanon
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy
| | - Martin Lévesque
- Department of Psychiatry and Neurosciences, Cervo Brain Research Centre, Université Laval, Quebec, QC, Canada
| | - Irene Pichler
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Bolzano, Italy
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Kumar R, Donakonda S, Müller SA, Bötzel K, Höglinger GU, Koeglsperger T. FGF2 Affects Parkinson's Disease-Associated Molecular Networks Through Exosomal Rab8b/Rab31. Front Genet 2020; 11:572058. [PMID: 33101391 PMCID: PMC7545478 DOI: 10.3389/fgene.2020.572058] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 09/02/2020] [Indexed: 01/24/2023] Open
Abstract
Ras-associated binding (Rab) proteins are small GTPases that regulate the trafficking of membrane components during endocytosis and exocytosis including the release of extracellular vesicles (EVs). Parkinson’s disease (PD) is one of the most prevalent neurodegenerative disorder in the elderly population, where pathological proteins such as alpha-synuclein (α-Syn) are transmitted in EVs from one neuron to another neuron and ultimately across brain regions, thereby facilitating the spreading of pathology. We recently demonstrated fibroblast growth factor-2 (FGF2) to enhance the release of EVs and delineated the proteomic signature of FGF2-triggered EVs in cultured primary hippocampal neurons. Out of 235 significantly upregulated proteins, we found that FGF2 specifically enriched EVs for the two Rab family members Rab8b and Rab31. Consequently, we investigated the interactions of Rab8b and Rab31 using a network analysis approach in order to estimate the global influence of their enrichment in EVs. To achieve this, we have demarcated a protein–protein interaction network (PPiN) for these Rabs and identified the proteins associated with PD in various cellular components of the central nervous system (CNS), in different brain regions, and in the enteric nervous system (ENS). A total of 126 direct or indirect interactions were reported for two Rab candidates, out of which 114 are Rab8b interactions and 54 are Rab31 interactions, ultimately resulting in an individual interaction score (IS) of 90.48 and 42.86%, respectively. Conclusively, these results for the first time demonstrate the relevance of FGF2-induced Rab-enrichment in EVs and its potential to regulate PD pathophysiology.
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Affiliation(s)
- Rohit Kumar
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Faculty of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Neurology, Ludwig Maximilian University, Munich, Germany
| | - Sainitin Donakonda
- Institute of Immunology and Experimental Oncology, Technical University of Munich, Munich, Germany
| | - Stephan A Müller
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Kai Bötzel
- Department of Neurology, Ludwig Maximilian University, Munich, Germany
| | - Günter U Höglinger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Faculty of Medicine, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Neurology, Hannover Medical School, Hanover, Germany
| | - Thomas Koeglsperger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, Ludwig Maximilian University, Munich, Germany
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Newberry RW, Arhar T, Costello J, Hartoularos GC, Maxwell AM, Naing ZZC, Pittman M, Reddy NR, Schwarz DMC, Wassarman DR, Wu TS, Barrero D, Caggiano C, Catching A, Cavazos TB, Estes LS, Faust B, Fink EA, Goldman MA, Gomez YK, Gordon MG, Gunsalus LM, Hoppe N, Jaime-Garza M, Johnson MC, Jones MG, Kung AF, Lopez KE, Lumpe J, Martyn C, McCarthy EE, Miller-Vedam LE, Navarro EJ, Palar A, Pellegrino J, Saylor W, Stephens CA, Strickland J, Torosyan H, Wankowicz SA, Wong DR, Wong G, Redding S, Chow ED, DeGrado WF, Kampmann M. Robust Sequence Determinants of α-Synuclein Toxicity in Yeast Implicate Membrane Binding. ACS Chem Biol 2020; 15:2137-2153. [PMID: 32786289 DOI: 10.1021/acschembio.0c00339] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Protein conformations are shaped by cellular environments, but how environmental changes alter the conformational landscapes of specific proteins in vivo remains largely uncharacterized, in part due to the challenge of probing protein structures in living cells. Here, we use deep mutational scanning to investigate how a toxic conformation of α-synuclein, a dynamic protein linked to Parkinson's disease, responds to perturbations of cellular proteostasis. In the context of a course for graduate students in the UCSF Integrative Program in Quantitative Biology, we screened a comprehensive library of α-synuclein missense mutants in yeast cells treated with a variety of small molecules that perturb cellular processes linked to α-synuclein biology and pathobiology. We found that the conformation of α-synuclein previously shown to drive yeast toxicity-an extended, membrane-bound helix-is largely unaffected by these chemical perturbations, underscoring the importance of this conformational state as a driver of cellular toxicity. On the other hand, the chemical perturbations have a significant effect on the ability of mutations to suppress α-synuclein toxicity. Moreover, we find that sequence determinants of α-synuclein toxicity are well described by a simple structural model of the membrane-bound helix. This model predicts that α-synuclein penetrates the membrane to constant depth across its length but that membrane affinity decreases toward the C terminus, which is consistent with orthogonal biophysical measurements. Finally, we discuss how parallelized chemical genetics experiments can provide a robust framework for inquiry-based graduate coursework.
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Affiliation(s)
- Robert W. Newberry
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Taylor Arhar
- Chemistry and Chemical Biology Graduate Program, University of California, San Francisco, California 94143, United States
| | - Jean Costello
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - George C. Hartoularos
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Alison M. Maxwell
- Chemistry and Chemical Biology Graduate Program, University of California, San Francisco, California 94143, United States
| | - Zun Zar Chi Naing
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Maureen Pittman
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Nishith R. Reddy
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Daniel M. C. Schwarz
- Chemistry and Chemical Biology Graduate Program, University of California, San Francisco, California 94143, United States
| | - Douglas R. Wassarman
- Chemistry and Chemical Biology Graduate Program, University of California, San Francisco, California 94143, United States
| | - Taia S. Wu
- Chemistry and Chemical Biology Graduate Program, University of California, San Francisco, California 94143, United States
| | - Daniel Barrero
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Christa Caggiano
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Adam Catching
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Taylor B. Cavazos
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Laurel S. Estes
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Bryan Faust
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Elissa A. Fink
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Miriam A. Goldman
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Yessica K. Gomez
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - M. Grace Gordon
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Laura M. Gunsalus
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Nick Hoppe
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Maru Jaime-Garza
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Matthew C. Johnson
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Matthew G. Jones
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Andrew F. Kung
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Kyle E. Lopez
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Jared Lumpe
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Calla Martyn
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Elizabeth E. McCarthy
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Lakshmi E. Miller-Vedam
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Erik J. Navarro
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Aji Palar
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Jenna Pellegrino
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Wren Saylor
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Christina A. Stephens
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Jack Strickland
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Hayarpi Torosyan
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Stephanie A. Wankowicz
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Daniel R. Wong
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Garrett Wong
- Integrative Program in Quantitative Biology, University of California, San Francisco, California 94143, United States
| | - Sy Redding
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, United States
| | - Eric D. Chow
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, United States
| | - William F. DeGrado
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Martin Kampmann
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143, United States
- Institute for Neurodegenerative Disease, University of California, San Francisco, California 94143, United States
- Chan Zuckerberg Biohub, San Francisco, California 94158, United States
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Terry-Kantor E, Tripathi A, Imberdis T, LaVoie ZM, Ho GPH, Selkoe D, Fanning S, Ramalingam N, Dettmer U. Rapid Alpha-Synuclein Toxicity in a Neural Cell Model and Its Rescue by a Stearoyl-CoA Desaturase Inhibitor. Int J Mol Sci 2020; 21:E5193. [PMID: 32707907 PMCID: PMC7432784 DOI: 10.3390/ijms21155193] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/16/2020] [Accepted: 07/16/2020] [Indexed: 01/28/2023] Open
Abstract
Genetic and biochemical evidence attributes neuronal loss in Parkinson's disease (PD) and related brain diseases to dyshomeostasis of the 14 kDa protein α-synuclein (αS). There is no consensus on how αS exerts toxicity. Explanations range from disturbed vesicle biology to proteotoxicity caused by fibrillar aggregates. To probe these mechanisms further, robust cellular toxicity models are needed, but their availability is limited. We previously reported that a shift from dynamic multimers to monomers is an early event in αS dyshomeostasis, as caused by familial PD (fPD)-linked mutants such as E46K. Excess monomers accumulate in round, lipid-rich inclusions. Engineered αS '3K' (E35K+E46K+E61K) amplifies E46K, causing a PD-like, L-DOPA-responsive motor phenotype in transgenic mice. Here, we present a cellular model of αS neurotoxicity after transducing human neuroblastoma cells to express yellow fluorescent protein (YFP)-tagged αS 3K in a doxycycline-dependent manner. αS-3K::YFP induction causes pronounced growth defects that accord with cell death. We tested candidate compounds for their ability to restore growth, and stearoyl-CoA desaturase (SCD) inhibitors emerged as a molecule class with growth-restoring capacity, but the therapeutic window varied among compounds. The SCD inhibitor MF-438 fully restored growth while exerting no apparent cytotoxicity. Our αS bioassay will be useful for elucidating compound mechanisms, for pharmacokinetic studies, and for compound/genetic screens.
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Affiliation(s)
| | | | | | | | | | | | | | - Nagendran Ramalingam
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (E.T.-K.); (A.T.); (T.I.); (Z.M.L.); (G.P.H.H.); (D.S.); (S.F.)
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (E.T.-K.); (A.T.); (T.I.); (Z.M.L.); (G.P.H.H.); (D.S.); (S.F.)
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Cerium Oxide Nanoparticles Rescue α-Synuclein-Induced Toxicity in a Yeast Model of Parkinson's Disease. NANOMATERIALS 2020; 10:nano10020235. [PMID: 32013138 PMCID: PMC7075201 DOI: 10.3390/nano10020235] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/25/2020] [Accepted: 01/26/2020] [Indexed: 12/21/2022]
Abstract
Over the last decades, cerium oxide nanoparticles (CeO2 NPs) have gained great interest due to their potential applications, mainly in the fields of agriculture and biomedicine. Promising effects of CeO2 NPs are recently shown in some neurodegenerative diseases, but the mechanism of action of these NPs in Parkinson's disease (PD) remains to be investigated. This issue is addressed in the present study by using a yeast model based on the heterologous expression of the human α-synuclein (α-syn), the major component of Lewy bodies, which represent a neuropathological hallmark of PD. We observed that CeO2 NPs strongly reduce α-syn-induced toxicity in a dose-dependent manner. This effect is associated with the inhibition of cytoplasmic α-syn foci accumulation, resulting in plasma membrane localization of α-syn after NP treatment. Moreover, CeO2 NPs counteract the α-syn-induced mitochondrial dysfunction and decrease reactive oxygen species (ROS) production in yeast cells. In vitro binding assay using cell lysates showed that α-syn is adsorbed on the surface of CeO2 NPs, suggesting that these NPs may act as a strong inhibitor of α-syn toxicity not only acting as a radical scavenger, but through a direct interaction with α-syn in vivo.
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Parkinson's disease: proteinopathy or lipidopathy? NPJ PARKINSONS DISEASE 2020; 6:3. [PMID: 31909184 PMCID: PMC6941970 DOI: 10.1038/s41531-019-0103-7] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 12/02/2019] [Indexed: 12/16/2022]
Abstract
Lipids play a more significant role in Parkinson’s disease and its related brain disorders than is currently recognized, supporting a “lipid cascade”. The 14 kDa protein α-synuclein (αS) is strongly associated with Parkinson’s disease (PD), dementia with Lewy bodies (DLB), other synucleinopathies such as multiple system atrophy, and even certain forms of Alzheimer’s disease. Rigorously deciphering the biochemistry of αS in native systems is the key to developing treatments. αS is highly expressed in the brain, the second most lipid-rich organ, and has been proposed to be a lipid-binding protein that physiologically interacts with phospholipids and fatty acids (FAs). αS-rich cytoplasmic inclusions called Lewy bodies and Lewy neurites are the hallmark lesions of synucleinopathies. Excess αS–membrane interactions may trigger proteinaceous αS aggregation by stimulating its primary nucleation. However, αS may also exert its toxicity prior to or independent of its self-aggregation, e.g., via excessive membrane interactions, which may be promoted by certain lipids and FAs. A complex αS-lipid landscape exists, which comprises both physiological and pathological states of αS. As novel insights about the composition of Lewy lesions occur, new lipid-related PD drug candidates emerge, and genome-wide association studies (GWAS) increasingly validate new hits in lipid-associated pathways, it seems timely to review our current knowledge of lipids in PD and consider the roles for these pathways in synucleinopathies.αS ↔ lipid interplay: aspects of cellular αS homeostasis (blue oval), aspects of lipid homeostasis (green oval), and overlapping aspects. Pathological states are labeled in red. Simplified schematic of both select αS and select lipid species. Several existing publications suggest αS effects on lipids and vice versa, as indicated by arrows. DG diglyceride, ER endoplasmic reticulum, FA fatty acid, LD, lipid droplet, TG triglyceride. ![]()
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46
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Guerrero-Ferreira R, Taylor NM, Arteni AA, Kumari P, Mona D, Ringler P, Britschgi M, Lauer ME, Makky A, Verasdonck J, Riek R, Melki R, Meier BH, Böckmann A, Bousset L, Stahlberg H. Two new polymorphic structures of human full-length alpha-synuclein fibrils solved by cryo-electron microscopy. eLife 2019; 8:48907. [PMID: 31815671 PMCID: PMC6957273 DOI: 10.7554/elife.48907] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 11/30/2019] [Indexed: 12/19/2022] Open
Abstract
Intracellular inclusions rich in alpha-synuclein are a hallmark of several neuropathological diseases including Parkinson's disease (PD). Previously, we reported the structure of alpha-synuclein fibrils (residues 1-121), composed of two protofibrils that are connected via a densely-packed interface formed by residues 50-57 (Guerrero-Ferreira, eLife 218;7:e36402). We here report two new polymorphic atomic structures of alpha-synuclein fibrils termed polymorphs 2a and 2b, at 3.0 Å and 3.4 Å resolution, respectively. These polymorphs show a radically different structure compared to previously reported polymorphs. The new structures have a 10 nm fibril diameter and are composed of two protofilaments which interact via intermolecular salt-bridges between amino acids K45, E57 (polymorph 2a) or E46 (polymorph 2b). The non-amyloid component (NAC) region of alpha-synuclein is fully buried by previously non-described interactions with the N-terminus. A hydrophobic cleft, the location of familial PD mutation sites, and the nature of the protofilament interface now invite to formulate hypotheses about fibril formation, growth and stability.
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Affiliation(s)
- Ricardo Guerrero-Ferreira
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
| | - Nicholas Mi Taylor
- Structural Biology of Molecular Machines Group, Protein Structure & Function Programme, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ana-Andreea Arteni
- Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris Sud, Université Paris-Saclay, Gif-sur-Yvette, France.,Institut Fancois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Pratibha Kumari
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Daniel Mona
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Medicine Area, Neuroscience Discovery, Roche Innovation Center Basel, Basel, Switzerland
| | - Philippe Ringler
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
| | - Markus Britschgi
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Medicine Area, Neuroscience Discovery, Roche Innovation Center Basel, Basel, Switzerland
| | - Matthias E Lauer
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, Basel, Switzerland
| | - Ali Makky
- Institut Galien Paris-Sud, CNRS, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Joeri Verasdonck
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Roland Riek
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Ronald Melki
- Institut Fancois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Beat H Meier
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Anja Böckmann
- Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, Lyon, France
| | - Luc Bousset
- Institut Fancois Jacob (MIRCen), CEA and Laboratory of Neurodegenerative Diseases, CNRS, Fontenay-Aux-Roses, France
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel, Switzerland
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Vincent BM, Tardiff DF, Piotrowski JS, Aron R, Lucas MC, Chung CY, Bacherman H, Chen Y, Pires M, Subramaniam R, Doshi DB, Sadlish H, Raja WK, Solís EJ, Khurana V, Le Bourdonnec B, Scannevin RH, Rhodes KJ. Inhibiting Stearoyl-CoA Desaturase Ameliorates α-Synuclein Cytotoxicity. Cell Rep 2019; 25:2742-2754.e31. [PMID: 30517862 DOI: 10.1016/j.celrep.2018.11.028] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/19/2018] [Accepted: 11/05/2018] [Indexed: 12/18/2022] Open
Abstract
The lack of disease-modifying treatments for neurodegenerative disease stems in part from our rudimentary understanding of disease mechanisms and the paucity of targets for therapeutic intervention. Here we used an integrated discovery paradigm to identify a new therapeutic target for diseases caused by α-synuclein (α-syn), a small lipid-binding protein that misfolds and aggregates in Parkinson's disease and other disorders. Using unbiased phenotypic screening, we identified a series of compounds that were cytoprotective against α-syn-mediated toxicity by inhibiting the highly conserved enzyme stearoyl-CoA desaturase (SCD). Critically, reducing the levels of unsaturated membrane lipids by inhibiting SCD reduced α-syn toxicity in human induced pluripotent stem cell (iPSC) neuronal models. Taken together, these findings suggest that inhibition of fatty acid desaturation has potential as a therapeutic approach for the treatment of Parkinson's disease and other synucleinopathies.
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Affiliation(s)
- Benjamin M Vincent
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Daniel F Tardiff
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA.
| | - Jeff S Piotrowski
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Rebecca Aron
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Matthew C Lucas
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Chee Yeun Chung
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Helene Bacherman
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - YiQun Chen
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Michelle Pires
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Radha Subramaniam
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Dimple B Doshi
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Heather Sadlish
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Waseem K Raja
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Eric J Solís
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Vikram Khurana
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA; Ann Romney Center for Neurologic Disease, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Robert H Scannevin
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
| | - Kenneth J Rhodes
- Yumanity Therapeutics, 790 Memorial Drive, Suite 2C, Cambridge, MA 02139, USA
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48
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Killinger BA, Melki R, Brundin P, Kordower JH. Endogenous alpha-synuclein monomers, oligomers and resulting pathology: let's talk about the lipids in the room. NPJ PARKINSONS DISEASE 2019; 5:23. [PMID: 31728405 PMCID: PMC6851126 DOI: 10.1038/s41531-019-0095-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/09/2019] [Indexed: 12/11/2022]
Abstract
Alpha-synuclein is an intrinsically disordered, highly dynamic protein that pathogenically aggregates into inclusion structures called Lewy bodies, in several neurogenerative diseases termed synucleinopathies. Despite its importance for understanding disease, the oligomerization status of alpha-synuclein in healthy cells remains unclear. Alpha-synuclein may exist predominantly as either a monomer or a variety of oligomers of different molecular weights. There is solid evidence to support both theories. Detection of apparent endogenous oligomers are intimately dependent on vesicle and lipid interactions. Here we consider the possibility that apparent endogenous alpha-synuclein oligomers are in fact conformations of membrane-bound alpha-synuclein and not a bona fide stable soluble species. This perspective posits that the formation of any alpha-synuclein oligomers within the cell is likely toxic and interconversion between monomer and oligomer is tightly controlled. This differs from the hypothesis that there is a continuum of endogenous non-toxic oligomers and they convert, through unclear mechanisms, to toxic oligomers. The distinction is important, because it clarifies the biological origin of synucleinopathy. We suggest that a monomer-only, lipid-centric view of endogenous alpha-synuclein aggregation can explain how alpha-synuclein pathology is triggered, and that the interactions between alpha-synuclein and lipids can represent a target for therapeutic intervention. This discussion is well-timed due to recent studies that show lipids are a significant component of Lewy pathology.
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Affiliation(s)
- Bryan A Killinger
- 1Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612 USA
| | - Ronald Melki
- 2CEA and Laboratory of Neurodegenerative Diseases, Institut Francois Jacob (MIRCen), CNRS, 92265 Fontenay-Aux-Roses cedex, France
| | - Patrik Brundin
- 3Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503 USA
| | - Jeffrey H Kordower
- 1Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612 USA
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49
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Cell models of lipid-rich α-synuclein aggregation validate known modifiers of α-synuclein biology and identify stearoyl-CoA desaturase. Proc Natl Acad Sci U S A 2019; 116:20760-20769. [PMID: 31548371 PMCID: PMC6789936 DOI: 10.1073/pnas.1903216116] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Misfolding and accumulation of the protein α-synuclein (αS) inside nerve cells characterize Parkinson’s disease (PD) and related brain diseases, for which no disease-modifying therapies exist. Robust cell models are needed that recapitulate abnormal αS folding/accumulation in real time, especially for compound screening. We took advantage of the engineered αS “3K” (E35K+E46K+E61K) mutation, which amplifies the familial PD-causing E46K and readily forms round inclusions. We rescued the inclusions with known αS modulators and then screened a ∼2,000-compound library. We identified the potential therapeutic target stearoyl-CoA desaturase; its inhibition cleared αS inclusions, in accord with the effects of conditioning in saturated fatty acids. We propose a model for how fatty acids serve as key modulators of cellular αS homeostasis. Microscopy of Lewy bodies in Parkinson’s disease (PD) suggests they are not solely filamentous deposits of α-synuclein (αS) but also contain vesicles and other membranous material. We previously reported the existence of native αS tetramers/multimers and described engineered mutations of the αS KTKEGV repeat motifs that abrogate the multimers. The resultant excess monomers accumulate in lipid membrane-rich inclusions associated with neurotoxicity exceeding that of natural familial PD mutants, such as E46K. Here, we use the αS “3K” (E35K+E46K+E61K) engineered mutation to probe the mechanisms of reported small-molecule modifiers of αS biochemistry and then identify compounds via a medium-throughput automated screen. αS 3K, which forms round, vesicle-rich inclusions in cultured neurons and causes a PD-like, l-DOPA–responsive motor phenotype in transgenic mice, was fused to YFP, and fluorescent inclusions were quantified. Live-cell microscopy revealed the highly dynamic nature of the αS inclusions: for example, their rapid clearance by certain known modulators of αS toxicity, including tacrolimus (FK506), isradipine, nilotinib, nortriptyline, and trifluoperazine. Our automated 3K cellular screen identified inhibitors of stearoyl-CoA desaturase (SCD) that robustly prevent the αS inclusions, reduce αS 3K neurotoxicity, and prevent abnormal phosphorylation and insolubility of αS E46K. SCD inhibition restores the E46K αS multimer:monomer ratio in human neurons, and it actually increases this ratio for overexpressed wild-type αS. In accord, conditioning 3K cells in saturated fatty acids rescued, whereas unsaturated fatty acids worsened, the αS phenotypes. Our cellular screen allows probing the mechanisms of synucleinopathy and refining drug candidates, including SCD inhibitors and other lipid modulators.
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50
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Yeboah F, Kim TE, Bill A, Dettmer U. Dynamic behaviors of α-synuclein and tau in the cellular context: New mechanistic insights and therapeutic opportunities in neurodegeneration. Neurobiol Dis 2019; 132:104543. [PMID: 31351173 DOI: 10.1016/j.nbd.2019.104543] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/18/2019] [Accepted: 07/22/2019] [Indexed: 10/26/2022] Open
Abstract
α-Synuclein (αS) and tau have a lot in common. Dyshomeostasis and aggregation of both proteins are central in the pathogenesis of neurodegenerative diseases: Parkinson's disease, dementia with Lewy bodies, multi-system atrophy and other 'synucleinopathies' in the case of αS; Alzheimer's disease, frontotemporal dementia, progressive supranuclear palsy and other 'tauopathies' in the case of tau. The aggregated states of αS and tau are found to be (hyper)phosphorylated, but the relevance of the phosphorylation in health or disease is not well understood. Both tau and αS are typically characterized as 'intrinsically disordered' proteins, while both engage in transient interactions with cellular components, thereby undergoing structural changes and context-specific folding. αS transiently binds to (synaptic) vesicles forming a membrane-induced amphipathic helix; tau transiently interacts with microtubules forming an 'extended structure'. The regulation and exact nature of the interactions are not fully understood. Here we review recent and previous insights into the dynamic, transient nature of αS and tau with regard to the mode of interaction with their targets, the dwell-time while bound, and the cis and trans factors underlying the frequent switching between bound and unbound states. These aspects are intimately linked to hypotheses on how subtle changes in the transient behaviors may trigger the earliest steps in the pathogenesis of the respective brain diseases. Based on a deeper understanding of transient αS and tau conformations in the cellular context, new therapeutic strategies may emerge, and it may become clearer why existing approaches have failed or how they could be optimized.
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Affiliation(s)
- Fred Yeboah
- Novartis Institute for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, MA 02139, USA
| | - Tae-Eun Kim
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Anke Bill
- Novartis Institute for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, MA 02139, USA.
| | - Ulf Dettmer
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
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