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Ishimoto T, Oono M, Kaji S, Ayaki T, Nishida K, Funakawa I, Maki T, Matsuzawa SI, Takahashi R, Yamakado H. A novel mouse model for investigating α-synuclein aggregates in oligodendrocytes: implications for the glial cytoplasmic inclusions in multiple system atrophy. Mol Brain 2024; 17:28. [PMID: 38790036 PMCID: PMC11127389 DOI: 10.1186/s13041-024-01104-7] [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: 12/18/2023] [Accepted: 05/20/2024] [Indexed: 05/26/2024] Open
Abstract
The aggregated alpha-synuclein (αsyn) in oligodendrocytes (OLGs) is one of the pathological hallmarks in multiple system atrophy (MSA). We have previously reported that αsyn accumulates not only in neurons but also in OLGs long after the administration of αsyn preformed fibrils (PFFs) in mice. However, detailed spatial and temporal analysis of oligodendroglial αsyn aggregates was technically difficult due to the background neuronal αsyn aggregates. The aim of this study is to create a novel mouse that easily enables sensitive and specific detection of αsyn aggregates in OLGs and the comparable analysis of the cellular tropism of αsyn aggregates in MSA brains. To this end, we generated transgenic (Tg) mice expressing human αsyn-green fluorescent protein (GFP) fusion proteins in OLGs under the control of the 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP) promoter (CNP-SNCAGFP Tg mice). Injection of αsyn PFFs in these mice induced distinct GFP-positive aggregates in the processes of OLGs as early as one month post-inoculation (mpi), and their number and size increased in a centripetal manner. Moreover, MSA-brain homogenates (BH) induced significantly more oligodendroglial αsyn aggregates than neuronal αsyn aggregates compared to DLB-BH in CNP-SNCAGFP Tg mice, suggestive of their potential tropism of αsyn seeds for OLGs. In conclusion, CNP-SNCAGFP Tg mice are useful for studying the development and tropism of αsyn aggregates in OLGs and could contribute to the development of therapeutics targeting αsyn aggregates in OLGs.
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Affiliation(s)
- Tomoyuki Ishimoto
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Miki Oono
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Seiji Kaji
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Takashi Ayaki
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Katsuya Nishida
- Department of Neurology, National Hospital Organization Hyogo-Chuo National Hospital, 1314 Ohara, Sanda, 669-1592, Japan
| | - Itaru Funakawa
- Department of Neurology, National Hospital Organization Hyogo-Chuo National Hospital, 1314 Ohara, Sanda, 669-1592, Japan
| | - Takakuni Maki
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Shu-Ichi Matsuzawa
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan
| | - Ryosuke Takahashi
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan.
| | - Hodaka Yamakado
- Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-Cho, Sakyo-Ku, Kyoto, 606-8507, Japan.
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Ibrahim KA, Naidu AS, Miljkovic H, Radenovic A, Yang W. Label-Free Techniques for Probing Biomolecular Condensates. ACS NANO 2024; 18:10738-10757. [PMID: 38609349 DOI: 10.1021/acsnano.4c01534] [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: 04/14/2024]
Abstract
Biomolecular condensates play important roles in a wide array of fundamental biological processes, such as cellular compartmentalization, cellular regulation, and other biochemical reactions. Since their discovery and first observations, an extensive and expansive library of tools has been developed to investigate various aspects and properties, encompassing structural and compositional information, material properties, and their evolution throughout the life cycle from formation to eventual dissolution. This Review presents an overview of the expanded set of tools and methods that researchers use to probe the properties of biomolecular condensates across diverse scales of length, concentration, stiffness, and time. In particular, we review recent years' exciting development of label-free techniques and methodologies. We broadly organize the set of tools into 3 categories: (1) imaging-based techniques, such as transmitted-light microscopy (TLM) and Brillouin microscopy (BM), (2) force spectroscopy techniques, such as atomic force microscopy (AFM) and the optical tweezer (OT), and (3) microfluidic platforms and emerging technologies. We point out the tools' key opportunities, challenges, and future perspectives and analyze their correlative potential as well as compatibility with other techniques. Additionally, we review emerging techniques, namely, differential dynamic microscopy (DDM) and interferometric scattering microscopy (iSCAT), that have huge potential for future applications in studying biomolecular condensates. Finally, we highlight how some of these techniques can be translated for diagnostics and therapy purposes. We hope this Review serves as a useful guide for new researchers in this field and aids in advancing the development of new biophysical tools to study biomolecular condensates.
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Santhosh Kumar S, Naseri NN, Pather SR, Hallacli E, Ndayisaba A, Buenaventura C, Acosta K, Roof J, Fazelinia H, Spruce LA, Luk K, Khurana V, Rhoades E, Shalem O. Sequential CRISPR screening reveals partial NatB inhibition as a strategy to mitigate alpha-synuclein levels in human neurons. SCIENCE ADVANCES 2024; 10:eadj4767. [PMID: 38335281 PMCID: PMC10857481 DOI: 10.1126/sciadv.adj4767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 01/11/2024] [Indexed: 02/12/2024]
Abstract
Alpha-synuclein (αSyn) protein levels correlate with the risk and severity of Parkinson's disease and related neurodegenerative diseases. Lowering αSyn is being actively investigated as a therapeutic modality. Here, we systematically map the regulatory network that controls endogenous αSyn using sequential CRISPR-knockout and -interference screens in an αSyn gene (SNCA)-tagged cell line and induced pluripotent stem cell-derived neurons (iNeurons). We uncover αSyn modifiers at multiple regulatory layers, with amino-terminal acetyltransferase B (NatB) enzymes being the most potent endogenous αSyn modifiers in both cell lines. Amino-terminal acetylation protects the cytosolic αSyn from rapid degradation by the proteasome in a Ube2w-dependent manner. Moreover, we show that pharmacological inhibition of methionyl-aminopeptidase 2, a regulator of NatB complex formation, attenuates endogenous αSyn in iNeurons carrying SNCA triplication. Together, our study reveals several gene networks that control endogenous αSyn, identifies mechanisms mediating the degradation of nonacetylated αSyn, and illustrates potential therapeutic pathways for decreasing αSyn levels in synucleinopathies.
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Affiliation(s)
- Saranya Santhosh Kumar
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nima N. Naseri
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Sarshan R. Pather
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Erinc Hallacli
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Alain Ndayisaba
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Chris Buenaventura
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Karen Acosta
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Jennifer Roof
- Proteomics Core Facility, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Hossein Fazelinia
- Proteomics Core Facility, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Biomedical and Health Informatics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Lynn A. Spruce
- Proteomics Core Facility, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kelvin Luk
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Vikram Khurana
- Division of Movement Disorders and Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Harvard Stem Cell Institute, Cambridge, MA, USA
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, USA
| | - Ophir Shalem
- Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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4
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Ibrahim KA, Grußmayer KS, Riguet N, Feletti L, Lashuel HA, Radenovic A. Label-free identification of protein aggregates using deep learning. Nat Commun 2023; 14:7816. [PMID: 38016971 PMCID: PMC10684545 DOI: 10.1038/s41467-023-43440-7] [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: 04/23/2023] [Accepted: 11/09/2023] [Indexed: 11/30/2023] Open
Abstract
Protein misfolding and aggregation play central roles in the pathogenesis of various neurodegenerative diseases (NDDs), including Huntington's disease, which is caused by a genetic mutation in exon 1 of the Huntingtin protein (Httex1). The fluorescent labels commonly used to visualize and monitor the dynamics of protein expression have been shown to alter the biophysical properties of proteins and the final ultrastructure, composition, and toxic properties of the formed aggregates. To overcome this limitation, we present a method for label-free identification of NDD-associated aggregates (LINA). Our approach utilizes deep learning to detect unlabeled and unaltered Httex1 aggregates in living cells from transmitted-light images, without the need for fluorescent labeling. Our models are robust across imaging conditions and on aggregates formed by different constructs of Httex1. LINA enables the dynamic identification of label-free aggregates and measurement of their dry mass and area changes during their growth process, offering high speed, specificity, and simplicity to analyze protein aggregation dynamics and obtain high-fidelity information.
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Affiliation(s)
- Khalid A Ibrahim
- Laboratory of Nanoscale Biology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Kristin S Grußmayer
- Department of Bionanoscience and Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands.
| | - Nathan Riguet
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Lely Feletti
- Laboratory of Nanoscale Biology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Aleksandra Radenovic
- Laboratory of Nanoscale Biology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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Protective mechanisms by glial cell line-derived neurotrophic factor and cerebral dopamine neurotrophic factor against the α-synuclein accumulation in Parkinson's disease. Biochem Soc Trans 2023; 51:245-257. [PMID: 36794783 DOI: 10.1042/bst20220770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 02/17/2023]
Abstract
Synucleinopathies constitute a disease family named after alpha-synuclein protein, which is a significant component of the intracellular inclusions called Lewy bodies. Accompanying the progressive neurodegeneration, Lewy bodies and neurites are the main histopathologies of synucleinopathies. The complicated role of alpha-synuclein in the disease pathology makes it an attractive therapeutic target for disease-modifying treatments. GDNF is one of the most potent neurotrophic factors for dopamine neurons, whereas CDNF is protective and neurorestorative with entirely different mechanisms of action. Both have been in the clinical trials for the most common synucleinopathy, Parkinson's disease. With the AAV-GDNF clinical trials ongoing and the CDNF trial being finalized, their effects on abnormal alpha-synuclein accumulation are of great interest. Previous animal studies with an alpha-synuclein overexpression model have shown that GDNF was ineffective against alpha-synuclein accumulation. However, a recent study with cell culture and animal models of alpha-synuclein fibril inoculation has demonstrated the opposite by revealing that the GDNF/RET signaling cascade is required for the protective effect of GDNF on alpha-synuclein aggregation. CDNF, an ER resident protein, was shown to bind alpha-synuclein directly. CDNF reduced the uptake of alpha-synuclein fibrils by the neurons and alleviated the behavioral deficits induced by fibrils injected into the mouse brain. Thus, GDNF and CDNF can modulate different symptoms and pathologies of Parkinson's disease, and perhaps, similarly for other synucleinopathies. Their unique mechanisms for preventing alpha-synuclein-related pathology should be studied more carefully to develop disease-modifying therapies.
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6
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Ni R. PET imaging in animal models of Parkinson's disease. Behav Brain Res 2023; 438:114174. [PMID: 36283568 DOI: 10.1016/j.bbr.2022.114174] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/20/2022] [Accepted: 09/27/2022] [Indexed: 12/05/2022]
Abstract
Alpha-synucleinopathies, such as Parkinson's disease, dementia with Lewy bodies and multiple system atrophy, are characterized by aberrant accumulation of alpha-synuclein and synaptic dysfunction leading to motor and cognitive deficits. Animal models of alpha-synucleinopathy have greatly facilitated the mechanistic understanding of the disease and the development of therapeutics. Various transgenic, alpha-synuclein fibril-injected, and toxin-injected animal models of Parkinson's disease and multiple system atrophy that recapitulate the disease pathology have been developed and widely used. Recent advances in positron emission tomography have allowed the noninvasive visualization of molecular alterations, underpinning behavioral dysfunctions in the brains of animal models and the longitudinal monitoring of treatment effects. Imaging studies in these disease animal models have employed multi-tracer PET designs to reveal dopaminergic deficits together with other molecular alterations. This review focuses on the development of new positron emission tomography tracers and studies of alpha-synuclein, synaptic vesicle glycoprotein 2A neurotransmitter receptor deficits such as dopaminergic receptor, dopaminergic transporter, serotonergic receptor, vesicular monoamine transporter 2, hypometabolism, neuroinflammation, mitochondrial dysfunction and leucine rich repeat kinase 2 in animal models of Parkinson's disease. The outstanding challenges and emerging applications are outlined, such as investigating the gut-brain-axis by using positron emission tomography in animal models, and provide a future outlook.
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Affiliation(s)
- Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
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7
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Dissecting aggregation and seeding dynamics of α-Syn polymorphs using the phasor approach to FLIM. Commun Biol 2022; 5:1345. [PMID: 36477485 PMCID: PMC9729209 DOI: 10.1038/s42003-022-04289-6] [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: 03/23/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Synucleinopathies are a heterogenous group of neurodegenerative diseases characterized by the progressive accumulation of pathological α-synuclein (α-Syn). The importance of structural polymorphism of α-Syn assemblies for distinct synucleinopathies and their progression is increasingly recognized. However, the underlying mechanisms are poorly understood. Here we use fluorescence lifetime imaging microscopy (FLIM) to investigate seeded aggregation of α-Syn in a biosensor cell line. We show that conformationally distinct α-Syn polymorphs exhibit characteristic fluorescence lifetimes. FLIM further revealed that α-Syn polymorphs were differentially processed by cellular clearance pathways, yielding fibrillar species with increased seeding capacity. Thus, FLIM is not only a powerful tool to distinguish different amyloid structures, but also to monitor the dynamic process of amyloid remodeling by the cellular environment. Our data suggest that the accumulation of highly seeding competent degradation products for particular polymorphs may account for accelerated disease progression in some patients.
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Kasen A, Houck C, Burmeister AR, Sha Q, Brundin L, Brundin P. Upregulation of α-synuclein following immune activation: Possible trigger of Parkinson's disease. Neurobiol Dis 2022; 166:105654. [DOI: 10.1016/j.nbd.2022.105654] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 12/20/2022] Open
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Shillcock JC, Hastings J, Riguet N, Lashuel HA. Non-monotonic fibril surface occlusion by GFP tags from coarse-grained molecular simulations. Comput Struct Biotechnol J 2021; 20:309-321. [PMID: 35070162 PMCID: PMC8753129 DOI: 10.1016/j.csbj.2021.12.017] [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: 11/04/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 11/23/2022] Open
Abstract
The pathological growth of amyloid fibrils in neurons underlies the progression of neurodegenerative diseases including Alzheimer's and Parkinson's disease. Fibrils form when soluble monomers oligomerise in the cytoplasm. Their subsequent growth occurs via nucleated polymerization mechanisms involving the free ends of the fibrils augmented by secondary nucleation of new oligomers at their surface. Amyloid fibrils possess a complex interactome with diffusing cytoplasmic proteins that regulates many aspects of their growth, seeding capacity, biochemical activity and transition to pathological inclusions in diseased brains. Changes to their surface are also expected to modify their interactome, pathogenicity and spreading in the brain. Many assays visualise fibril formation, growth and inclusion formation by decorating monomeric proteins with fluorescent tags such as GFP. Recent studies from our group suggest that tags with sizes comparable to the fibril radius may modify the fibril surface accessibility and thus their PTM pattern, interactome and ability to form inclusions. Using coarse-grained molecular simulations of a single alpha synuclein fibril tagged with GFP we find that thermal fluctuations of the tags create a non-monotonic, size-dependent sieve around the fibril that perturbs its interactome with diffusing species. Our results indicate that experiments using tagged and untagged monomers to study the growth and interactome of fibrils should be compared with caution, and the confounding effects of the tags are more complex than a reduction in surface accessibility. The prevalence of fluorescent tags in amyloid fibril growth experiments suggests this has implications beyond the specific alpha synuclein fibrils we model here.
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Affiliation(s)
- Julian C. Shillcock
- Blue Brain Project, Ecole polytechnique fédérale de Lausanne, CH-1202 Geneva, Switzerland
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Janna Hastings
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- Bioinformatics Competence Center, Ecole polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Nathan Riguet
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - Hilal A. Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Ecole polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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Specht CG. A Quantitative Perspective of Alpha-Synuclein Dynamics - Why Numbers Matter. Front Synaptic Neurosci 2021; 13:753462. [PMID: 34744680 PMCID: PMC8569944 DOI: 10.3389/fnsyn.2021.753462] [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: 08/04/2021] [Accepted: 09/30/2021] [Indexed: 12/02/2022] Open
Abstract
The function of synapses depends on spatially and temporally controlled molecular interactions between synaptic components that can be described in terms of copy numbers, binding affinities, and diffusion properties. To understand the functional role of a given synaptic protein, it is therefore crucial to quantitatively characterise its biophysical behaviour in its native cellular environment. Single molecule localisation microscopy (SMLM) is ideally suited to obtain quantitative information about synaptic proteins on the nanometre scale. Molecule counting of recombinant proteins tagged with genetically encoded fluorophores offers a means to determine their absolute copy numbers at synapses due to the known stoichiometry of the labelling. As a consequence of its high spatial precision, SMLM also yields accurate quantitative measurements of molecule concentrations. In addition, live imaging of fluorescently tagged proteins at synapses can reveal diffusion dynamics and local binding properties of behaving proteins under normal conditions or during pathological processes. In this perspective, it is argued that the detailed structural information provided by super-resolution imaging can be harnessed to gain new quantitative information about the organisation and dynamics of synaptic components in cellula. To illustrate this point, I discuss the concentration-dependent aggregation of α-synuclein in the axon and the concomitant changes in the dynamic equilibrium of α-synuclein at synapses in quantitative terms.
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Affiliation(s)
- Christian G. Specht
- Diseases and Hormones of the Nervous System (DHNS), Inserm, Université Paris-Saclay, Paris, France
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11
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Polinski NK. A Summary of Phenotypes Observed in the In Vivo Rodent Alpha-Synuclein Preformed Fibril Model. JOURNAL OF PARKINSONS DISEASE 2021; 11:1555-1567. [PMID: 34486988 PMCID: PMC8609716 DOI: 10.3233/jpd-212847] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The use of wildtype recombinant alpha-synuclein preformed fibrils (aSyn PFFs) to induce endogenous alpha-synuclein to form pathological phosphorylation and trigger neurodegeneration is a popular model for studying Parkinson's disease (PD) biology and testing therapeutic strategies. The strengths of this model lie in its ability to recapitulate the phosphorylation/aggregation of aSyn and nigrostriatal degeneration seen in PD, as well as its suitability for studying the progressive nature of PD and the spread of aSyn pathology. Although the model is commonly used and has been adopted by many labs, variability in observed phenotypes exists. Here we provide summaries of the study design and reported phenotypes from published reports characterizing the aSyn PFF in vivo model in rodents following injection into the brain, gut, muscle, vein, peritoneum, and eye. These summaries are designed to facilitate an introduction to the use of aSyn PFFs to generate a rodent model of PD-highlighting phenotypes observed in papers that set out to thoroughly characterize the model. This information will hopefully improve the understanding of this model and clarify when the aSyn PFF model may be an appropriate choice for one's research.
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Affiliation(s)
- Nicole K Polinski
- The Michael J. Fox Foundation for Parkinson'sResearch, New York, NY, USA
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12
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Boutros SW, Raber J, Unni VK. Effects of Alpha-Synuclein Targeted Antisense Oligonucleotides on Lewy Body-Like Pathology and Behavioral Disturbances Induced by Injections of Pre-Formed Fibrils in the Mouse Motor Cortex. JOURNAL OF PARKINSONS DISEASE 2021; 11:1091-1115. [PMID: 34057097 PMCID: PMC8461707 DOI: 10.3233/jpd-212566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background: Alpha-synuclein (αsyn) characterizes neurodegenerative diseases known as synucleinopathies. The phosphorylated form (psyn) is the primary component of protein aggregates known as Lewy bodies (LBs), which are the hallmark of diseases such as Parkinson’s disease (PD). Synucleinopathies might spread in a prion-like fashion, leading to a progressive emergence of symptoms over time. αsyn pre-formed fibrils (PFFs) induce LB-like pathology in wild-type (WT) mice, but questions remain about their progressive spread and their associated effects on behavioral performance. Objective: To characterize the behavioral, cognitive, and pathological long-term effects of LB-like pathology induced after bilateral motor cortex PFF injection in WT mice and to assess the ability of mouse αsyn-targeted antisense oligonucleotides (ASOs) to ameliorate those effects. Methods: We induced LB-like pathology in the motor cortex and connected brain regions of male WT mice using PFFs. Three months post-PFF injection (mpi), we assessed behavioral and cognitive performance. We then delivered a targeted ASO via the ventricle and assessed behavioral and cognitive performance 5 weeks later, followed by pathological analysis. Results: At 3 and 6 mpi, PFF-injected mice showed mild, progressive behavioral deficits. The ASO reduced total αsyn and psyn protein levels, and LB-like pathology, but was also associated with some deleterious off-target effects not involving lowering of αsyn, such as a decline in body weight and impairments in motor function. Conclusions: These results increase understanding of the progressive nature of the PFF model and support the therapeutic potential of ASOs, though more investigation into effects of ASO-mediated reduction in αsyn on brain function is needed.
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Affiliation(s)
- Sydney Weber Boutros
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA.,Department of Neurology, Oregon Health & Science University, Portland, OR, USA.,Departments of Psychiatry and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR, USA
| | - Vivek K Unni
- Department of Neurology, Oregon Health & Science University, Portland, OR, USA.,Jungers Center for Neurosciences Research and OHSU Parkinson Center, Oregon Health & Science University, Portland, OR, USA
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13
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Cole TA, Zhao H, Collier TJ, Sandoval I, Sortwell CE, Steece-Collier K, Daley BF, Booms A, Lipton J, Welch M, Berman M, Jandreski L, Graham D, Weihofen A, Celano S, Schulz E, Cole-Strauss A, Luna E, Quach D, Mohan A, Bennett CF, Swayze EE, Kordasiewicz HB, Luk KC, Paumier KL. α-Synuclein antisense oligonucleotides as a disease-modifying therapy for Parkinson's disease. JCI Insight 2021; 6:135633. [PMID: 33682798 PMCID: PMC8021121 DOI: 10.1172/jci.insight.135633] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 01/27/2021] [Indexed: 12/14/2022] Open
Abstract
Parkinson's disease (PD) is a prevalent neurodegenerative disease with no approved disease-modifying therapies. Multiplications, mutations, and single nucleotide polymorphisms in the SNCA gene, encoding α-synuclein (aSyn) protein, either cause or increase risk for PD. Intracellular accumulations of aSyn are pathological hallmarks of PD. Taken together, reduction of aSyn production may provide a disease-modifying therapy for PD. We show that antisense oligonucleotides (ASOs) reduce production of aSyn in rodent preformed fibril (PFF) models of PD. Reduced aSyn production leads to prevention and removal of established aSyn pathology and prevents dopaminergic cell dysfunction. In addition, we address the translational potential of the approach through characterization of human SNCA-targeting ASOs that efficiently suppress the human SNCA transcript in vivo. We demonstrate broad activity and distribution of the human SNCA ASOs throughout the nonhuman primate brain and a corresponding decrease in aSyn cerebral spinal fluid (CSF) levels. Taken together, these data suggest that, by inhibiting production of aSyn, it may be possible to reverse established pathology; thus, these data support the development of SNCA ASOs as a potential disease-modifying therapy for PD and related synucleinopathies.
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Affiliation(s)
- Tracy A. Cole
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | - Hien Zhao
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | | | | | | | | | | | - Alix Booms
- Michigan State University, Grand Rapids, Michigan, USA
| | - Jack Lipton
- Michigan State University, Grand Rapids, Michigan, USA
| | | | | | | | | | | | | | - Emily Schulz
- Michigan State University, Grand Rapids, Michigan, USA
| | | | - Esteban Luna
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Duc Quach
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | - Apoorva Mohan
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | | | | | | | - Kelvin C. Luk
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
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14
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Snca-GFP Knock-In Mice Allows Tracking the Endogenous α-Synuclein in Action. eNeuro 2021; 8:8/1/ENEURO.0544-20.2021. [PMID: 33479114 PMCID: PMC7877455 DOI: 10.1523/eneuro.0544-20.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Highlighted Research Paper:Snca-GFP Knock-In Mice Reflect Patterns of Endogenous Expression and Pathologic Seeding, by Anna Caputo, Yuling Liang, Tobias D. Raabe, Angela Lo, Mian Horvath, Bin Zhang, Hannah J. Brown, Anna Stieber, and Kelvin C. Luk
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15
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Wu Q, Shaikh MA, Meymand ES, Zhang B, Luk KC, Trojanowski JQ, Lee VMY. Neuronal activity modulates alpha-synuclein aggregation and spreading in organotypic brain slice cultures and in vivo. Acta Neuropathol 2020; 140:831-849. [PMID: 33021680 DOI: 10.1007/s00401-020-02227-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022]
Abstract
Alpha-synuclein (αSyn) preformed fibrils (PFF) induce endogenous αSyn aggregation leading to reduced synaptic transmission. Neuronal activity modulates release of αSyn; however, whether neuronal activity regulates the spreading of αSyn pathology remains elusive. Here, we established a hippocampal slice culture system from wild-type (WT) mice and found that both Ca2+ influx and the uptake of αSyn PFF were higher in the CA3 than in the CA1 sub-region. Pharmacologically enhancing neuronal activity substantially increased αSyn pathology in αSyn PFF-treated hippocampal or midbrain slice cultures and accelerated dopaminergic neuron degeneration. Consistently, neuronal hyperactivity promoted PFF trafficking along axons/dendrites within microfluidic chambers. Unexpectedly, enhancing neuronal activity in LRRK2 G2019S mutant slice cultures further increased αSyn pathology, especially with more Lewy body (LB) forming than in WT slice cultures. Finally, following injection of αSyn PFF and chemogenetic modulators into the dorsal striatum of WT mice, both motor behavior and αSyn pathology were exacerbated likely by enhancing neuronal activity, since they were ameliorated by reducing neuronal activity. Thus, a greater understanding of the impact of neuronal activity on αSyn aggregation and spreading, as well as dopaminergic neuronal vulnerability, may provide new therapeutic strategies for patients with LB disease (LBD).
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Affiliation(s)
- Qihui Wu
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA
| | - Muhammad A Shaikh
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA
| | - Emily S Meymand
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA
| | - Bin Zhang
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA
| | - Kelvin C Luk
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA
| | - Virginia M-Y Lee
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104-4283, USA.
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