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Babu HWS, Kumar SM, Kaur H, Iyer M, Vellingiri B. Midbrain organoids for Parkinson's disease (PD) - A powerful tool to understand the disease pathogenesis. Life Sci 2024; 345:122610. [PMID: 38580194 DOI: 10.1016/j.lfs.2024.122610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/26/2024] [Accepted: 04/01/2024] [Indexed: 04/07/2024]
Abstract
Brain Organiods (BOs) are a promising technique for researching disease progression in the human brain. These organoids, which are produced from human induced pluripotent stem cells (HiPSCs), can construct themselves into structured frameworks. In the context of Parkinson's disease (PD), recent advancements have been made in the development of Midbrain organoids (MBOs) models that consider key pathophysiological mechanisms such as alpha-synuclein (α-Syn), Lewy bodies, dopamine loss, and microglia activation. However, there are limitations to the current use of BOs in disease modelling and drug discovery, such as the lack of vascularization, long-term differentiation, and absence of glial cells. To address these limitations, researchers have proposed the use of spinning bioreactors to improve oxygen and nutrient perfusion. Modelling PD utilising modern experimental in vitro models is a valuable tool for studying disease mechanisms and elucidating previously unknown features of PD. In this paper, we exclusively review the unique methods available for cultivating MBOs using a pumping system that mimics the circulatory system. This mechanism may aid in delivering the required amount of oxygen and nutrients to all areas of the organoids, preventing cell death, and allowing for long-term culture and using co-culturing techniques for developing glial cell in BOs. Furthermore, we emphasise some of the significant discoveries about the BOs and the potential challenges of using BOs will be discussed.
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Affiliation(s)
- Harysh Winster Suresh Babu
- Human Cytogenetics and Stem Cell Laboratory, Department of Zoology, School of Basic Sciences, Central University of Punjab, Bathinda 151401, Punjab, India
| | - Sindduja Muthu Kumar
- Human Cytogenetics and Stem Cell Laboratory, Department of Zoology, School of Basic Sciences, Central University of Punjab, Bathinda 151401, Punjab, India
| | - Harsimrat Kaur
- Human Cytogenetics and Stem Cell Laboratory, Department of Zoology, School of Basic Sciences, Central University of Punjab, Bathinda 151401, Punjab, India
| | - Mahalaxmi Iyer
- Centre for Neuroscience, Department of Biotechnology, Karpagam Academy of Higher Education, Coimbatore-641021, Tamil Nadu, India; Department of Microbiology, School of Basic Sciences, Central University of Punjab, Bathinda 151401, Punjab, India
| | - Balachandar Vellingiri
- Human Cytogenetics and Stem Cell Laboratory, Department of Zoology, School of Basic Sciences, Central University of Punjab, Bathinda 151401, Punjab, India.
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2
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Makasewicz K, Linse S, Sparr E. Interplay of α-synuclein with Lipid Membranes: Cooperative Adsorption, Membrane Remodeling and Coaggregation. JACS AU 2024; 4:1250-1262. [PMID: 38665673 PMCID: PMC11040681 DOI: 10.1021/jacsau.3c00579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/18/2024] [Accepted: 01/18/2024] [Indexed: 04/28/2024]
Abstract
α-Synuclein is a small neuronal protein enriched at presynaptic termini. It is hypothesized to play a role in neurotransmitter release and synaptic vesicle cycling, while the formation of α-synuclein amyloid fibrils is associated with several neurodegenerative diseases, most notably Parkinson's Disease. The molecular mechanisms of both the physiological and pathological functions of α-synuclein remain to be fully understood, but in both cases, interactions with membranes play an important role. In this Perspective, we discuss several aspects of α-synuclein interactions with lipid membranes including cooperative adsorption, membrane remodeling and α-synuclein amyloid fibril formation in the presence of lipid membranes. We highlight the coupling between the different phenomena and their interplay in the context of physiological and pathological functions of α-synuclein.
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Affiliation(s)
- Katarzyna Makasewicz
- Division
of Physical Chemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Sara Linse
- Biochemistry
and Structural Biology, Lund University, SE-22100 Lund, Sweden
| | - Emma Sparr
- Department
of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
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3
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Smith AN, Joshi S, Chanzu H, Alfar HR, Prakhya KS, Whiteheart SW. α-Synuclein is the major platelet isoform but is dispensable for activation, secretion, and thrombosis. Platelets 2023; 34:2267147. [PMID: 37927048 PMCID: PMC10629845 DOI: 10.1080/09537104.2023.2267147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/01/2023] [Indexed: 11/07/2023]
Abstract
Platelets play many roles in the vasculature ensuring proper hemostasis and maintaining integrity. These roles are facilitated, in part, by cargo molecules released from platelet granules via Soluble NSF Attachment Protein Receptor (SNARE) mediated membrane fusion, which is controlled by several protein-protein interactions. Chaperones have been characterized for t-SNAREs (i.e. Munc18b for Syntaxin-11), but none have been clearly identified for v-SNAREs. α-Synuclein has been proposed as a v-SNARE chaperone which may affect SNARE-complex assembly, fusion pore opening, and thus secretion. Despite its abundance and that it is the only isoform present, α-synuclein's role in platelet secretion is uncharacterized. In this study, immunofluorescence showed that α-synuclein was present on punctate structures that co-stained with markers for α-granules and lysosomes and in a cytoplasmic pool. We analyzed the phenotype of α-synuclein-/- mice and their platelets. Platelets from knockout mice had a mild, agonist-dependent secretion defect but aggregation and spreading in vitro were unaffected. Consistently, thrombosis/hemostasis were unaffected in the tail-bleeding, FeCl3 carotid injury and jugular vein puncture models. None of the platelet secretory machinery examined, e.g. the v-SNAREs, were affected by α-synuclein's loss. The results indicate that, despite its abundance, α-synuclein has only a limited role in platelet function and thrombosis.
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Affiliation(s)
- Alexis N. Smith
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Smita Joshi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Harry Chanzu
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
- Present address: GenScript USA Inc., 860 Centennial Ave. Piscataway, NJ 08854, USA
| | - Hammodah R. Alfar
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | | | - Sidney W. Whiteheart
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
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4
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Brolin E, Ingelsson M, Bergström J, Erlandsson A. Altered Distribution of SNARE Proteins in Primary Neurons Exposed to Different Alpha-Synuclein Proteoforms. Cell Mol Neurobiol 2023:10.1007/s10571-023-01355-3. [PMID: 37130995 DOI: 10.1007/s10571-023-01355-3] [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] [Received: 03/15/2023] [Accepted: 04/19/2023] [Indexed: 05/04/2023]
Abstract
Growing evidence indicates that the pathological alpha-synuclein (α-syn) aggregation in Parkinson's disease (PD) and dementia with Lewy bodies (DLB) starts at the synapses. Physiologic α-syn is involved in regulating neurotransmitter release by binding to the SNARE complex protein VAMP-2 on synaptic vesicles. However, in which way the SNARE complex formation is affected by α-syn pathology remains unclear. In this study, primary cortical neurons were exposed to either α-syn monomers or preformed fibrils (PFFs) for different time points and the effect on SNARE protein distribution was analyzed with a novel proximity ligation assay (PLA). Short-term exposure to monomers or PFFs for 24 h increased the co-localization of VAMP-2 and syntaxin-1, but reduced the co-localization of SNAP-25 and syntaxin-1, indicating a direct effect of the added α-syn on SNARE protein distribution. Long-term exposure to α-syn PFFs for 7 d reduced VAMP-2 and SNAP-25 co-localization, although there was only a modest induction of ser129 phosphorylated (pS129) α-syn. Similarly, exposure to extracellular vesicles collected from astrocytes treated with α-syn PFFs for 7 d influenced VAMP-2 and SNAP-25 co-localization despite only low levels of pS129 α-syn being formed. Taken together, our results demonstrate that different α-syn proteoforms have the potential to alter the distribution of SNARE proteins at the synapse.
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Affiliation(s)
- Emma Brolin
- Department of Public Health and Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37, Uppsala, Sweden
| | - Martin Ingelsson
- Department of Public Health and Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37, Uppsala, Sweden
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Department of Medicine and Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
| | - Joakim Bergström
- Department of Public Health and Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37, Uppsala, Sweden
| | - Anna Erlandsson
- Department of Public Health and Caring Sciences/Molecular Geriatrics, Rudbeck Laboratory, Uppsala University, SE-752 37, Uppsala, Sweden.
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5
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Sohrabi T, Mirzaei-Behbahani B, Zadali R, Pirhaghi M, Morozova-Roche LA, Meratan AA. Common Mechanisms Underlying α-Synuclein-Induced Mitochondrial Dysfunction in Parkinson's Disease. J Mol Biol 2023:167992. [PMID: 36736886 DOI: 10.1016/j.jmb.2023.167992] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/19/2023] [Accepted: 01/24/2023] [Indexed: 02/05/2023]
Abstract
Parkinson's disease (PD) is the most common neurological movement disorder characterized by the selective and irreversible loss of dopaminergic neurons in substantia nigra pars compacta resulting in dopamine deficiency in the striatum. While most cases are sporadic or environmental, about 10% of patients have a positive family history with a genetic cause. The misfolding and aggregation of α-synuclein (α-syn) as a casual factor in the pathogenesis of PD has been supported by a great deal of literature. Extensive studies of mechanisms underpinning degeneration of the dopaminergic neurons induced by α-syn dysfunction suggest a complex process that involves multiple pathways, including mitochondrial dysfunction and increased oxidative stress, impaired calcium homeostasis through membrane permeabilization, synaptic dysfunction, impairment of quality control systems, disruption of microtubule dynamics and axonal transport, endoplasmic reticulum/Golgi dysfunction, nucleus malfunction, and microglia activation leading to neuroinflammation. Among them mitochondrial dysfunction has been considered as the most primary target of α-syn-induced toxicity, leading to neuronal cell death in both sporadic and familial forms of PD. Despite reviewing many aspects of PD pathogenesis related to mitochondrial dysfunction, a systemic study on how α-syn malfunction/aggregation damages mitochondrial functionality and leads to neurodegeneration is missing in the literature. In this review, we give a detailed molecular overview of the proposed mechanisms by which α-syn, directly or indirectly, contributes to mitochondrial dysfunction. This may provide valuable insights for development of new therapeutic approaches in relation to PD. Antioxidant-based therapy as a potential strategy to protect mitochondria against oxidative damage, its challenges, and recent developments in the field are discussed.
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Affiliation(s)
- Tahereh Sohrabi
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Behnaz Mirzaei-Behbahani
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Ramin Zadali
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Mitra Pirhaghi
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | | | - Ali Akbar Meratan
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran.
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6
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The Interplay between α-Synuclein and Microglia in α-Synucleinopathies. Int J Mol Sci 2023; 24:ijms24032477. [PMID: 36768798 PMCID: PMC9916729 DOI: 10.3390/ijms24032477] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/19/2023] [Accepted: 01/24/2023] [Indexed: 02/01/2023] Open
Abstract
Synucleinopathies are a set of devastating neurodegenerative diseases that share a pathologic accumulation of the protein α-synuclein (α-syn). This accumulation causes neuronal death resulting in irreversible dementia, deteriorating motor symptoms, and devastating cognitive decline. While the etiology of these conditions remains largely unknown, microglia, the resident immune cells of the central nervous system (CNS), have been consistently implicated in the pathogenesis of synucleinopathies. Microglia are generally believed to be neuroprotective in the early stages of α-syn accumulation and contribute to further neurodegeneration in chronic disease states. While the molecular mechanisms by which microglia achieve this role are still being investigated, here we highlight the major findings to date. In this review, we describe how structural varieties of inherently disordered α-syn result in varied microglial receptor-mediated interactions. We also summarize which microglial receptors enable cellular recognition and uptake of α-syn. Lastly, we review the downstream effects of α-syn processing within microglia, including spread to other brain regions resulting in neuroinflammation and neurodegeneration in chronic disease states. Understanding the mechanism of microglial interactions with α-syn is vital to conceptualizing molecular targets for novel therapeutic interventions. In addition, given the significant diversity in the pathophysiology of synucleinopathies, such molecular interactions are vital in gauging all potential pathways of neurodegeneration in the disease state.
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7
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The Role of α-Synuclein in SNARE-mediated Synaptic Vesicle Fusion. J Mol Biol 2023; 435:167775. [PMID: 35931109 DOI: 10.1016/j.jmb.2022.167775] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 02/04/2023]
Abstract
Neuronal communication depends on exquisitely regulated membrane fusion between synaptic vesicles and presynaptic neurons, which results in neurotransmitter release in precisely timed patterns. Presynaptic dysfunctions are known to occur prior to the onset of neurodegenerative diseases, including Parkinson's disease. Synaptic accumulation of α-synuclein (α-Syn) oligomers has been implicated in the pathway leading to such outcomes. α-Syn oligomers exert aberrant effects on presynaptic fusion machinery through their interactions with synaptic vesicles and proteins. Here, we summarize in vitro bulk and single-vesicle assays for investigating the functions of α-Syn monomers and oligomers in synaptic vesicle fusion and then discuss the current understanding of the roles of α-Syn monomers and oligomers in synaptic vesicle fusion. Finally, we suggest a new therapeutic avenue specifically targeting the mechanisms of α-Syn oligomer toxicity rather than the oligomer itself.
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8
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Gao V, Briano JA, Komer LE, Burré J. Functional and Pathological Effects of α-Synuclein on Synaptic SNARE Complexes. J Mol Biol 2023; 435:167714. [PMID: 35787839 PMCID: PMC10472340 DOI: 10.1016/j.jmb.2022.167714] [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: 05/08/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 02/07/2023]
Abstract
α-Synuclein is an abundant protein at the neuronal synapse that has been implicated in Parkinson's disease for over 25 years and characterizes the hallmark pathology of a group of neurodegenerative diseases now known as the synucleinopathies. Physiologically, α-synuclein exists in an equilibrium between a synaptic vesicle membrane-bound α-helical multimer and a cytosolic largely unstructured monomer. Through its membrane-bound state, α-synuclein functions in neurotransmitter release by modulating several steps in the synaptic vesicle cycle, including synaptic vesicle clustering and docking, SNARE complex assembly, and homeostasis of synaptic vesicle pools. These functions have been ascribed to α-synuclein's interactions with the synaptic vesicle SNARE protein VAMP2/synaptobrevin-2, the synaptic vesicle-attached synapsins, and the synaptic vesicle membrane itself. How α-synuclein affects these processes, and whether disease is due to loss-of-function or gain-of-toxic-function of α-synuclein remains unclear. In this review, we provide an in-depth summary of the existing literature, discuss possible reasons for the discrepancies in the field, and propose a working model that reconciles the findings in the literature.
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Affiliation(s)
- Virginia Gao
- Appel Alzheimer's Disease Research Institute & Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA; Department of Neurology, New York Presbyterian/Weill Cornell Medicine, New York, NY, USA.
| | - Juan A Briano
- Appel Alzheimer's Disease Research Institute & Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Lauren E Komer
- Appel Alzheimer's Disease Research Institute & Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA. https://www.twitter.com/lauren_komer
| | - Jacqueline Burré
- Appel Alzheimer's Disease Research Institute & Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
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9
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The Role of Membrane Affinity and Binding Modes in Alpha-Synuclein Regulation of Vesicle Release and Trafficking. Biomolecules 2022; 12:biom12121816. [PMID: 36551244 PMCID: PMC9775087 DOI: 10.3390/biom12121816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/02/2022] [Accepted: 11/27/2022] [Indexed: 12/12/2022] Open
Abstract
Alpha-synuclein is a presynaptic protein linked to Parkinson's disease with a poorly characterized physiological role in regulating the synaptic vesicle cycle. Using RBL-2H3 cells as a model system, we earlier reported that wild-type alpha-synuclein can act as both an inhibitor and a potentiator of stimulated exocytosis in a concentration-dependent manner. The inhibitory function is constitutive and depends on membrane binding by the helix-2 region of the lipid-binding domain, while potentiation becomes apparent only at high concentrations. Using structural and functional characterization of conformationally selective mutants via a combination of spectroscopic and cellular assays, we show here that binding affinity for isolated vesicles similar in size to synaptic vesicles is a primary determinant of alpha-synuclein-mediated potentiation of vesicle release. Inhibition of release is sensitive to changes in the region linking the helix-1 and helix-2 regions of the N-terminal lipid-binding domain and may require some degree of coupling between these regions. Potentiation of release likely occurs as a result of alpha-synuclein interactions with undocked vesicles isolated away from the active zone in internal pools. Consistent with this, we observe that alpha-synuclein can disperse vesicles from in vitro clusters organized by condensates of the presynaptic protein synapsin-1.
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10
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Cui L, Li H, Xi Y, Hu Q, Liu H, Fan J, Xiang Y, Zhang X, Shui W, Lai Y. Vesicle trafficking and vesicle fusion: mechanisms, biological functions, and their implications for potential disease therapy. MOLECULAR BIOMEDICINE 2022; 3:29. [PMID: 36129576 PMCID: PMC9492833 DOI: 10.1186/s43556-022-00090-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/12/2022] [Indexed: 11/10/2022] Open
Abstract
Intracellular vesicle trafficking is the fundamental process to maintain the homeostasis of membrane-enclosed organelles in eukaryotic cells. These organelles transport cargo from the donor membrane to the target membrane through the cargo containing vesicles. Vesicle trafficking pathway includes vesicle formation from the donor membrane, vesicle transport, and vesicle fusion with the target membrane. Coat protein mediated vesicle formation is a delicate membrane budding process for cargo molecules selection and package into vesicle carriers. Vesicle transport is a dynamic and specific process for the cargo containing vesicles translocation from the donor membrane to the target membrane. This process requires a group of conserved proteins such as Rab GTPases, motor adaptors, and motor proteins to ensure vesicle transport along cytoskeletal track. Soluble N-ethyl-maleimide-sensitive factor (NSF) attachment protein receptors (SNARE)-mediated vesicle fusion is the final process for vesicle unloading the cargo molecules at the target membrane. To ensure vesicle fusion occurring at a defined position and time pattern in eukaryotic cell, multiple fusogenic proteins, such as synaptotagmin (Syt), complexin (Cpx), Munc13, Munc18 and other tethering factors, cooperate together to precisely regulate the process of vesicle fusion. Dysfunctions of the fusogenic proteins in SNARE-mediated vesicle fusion are closely related to many diseases. Recent studies have suggested that stimulated membrane fusion can be manipulated pharmacologically via disruption the interface between the SNARE complex and Ca2+ sensor protein. Here, we summarize recent insights into the molecular mechanisms of vesicle trafficking, and implications for the development of new therapeutics based on the manipulation of vesicle fusion.
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11
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Huis In 't Veld RV, Lara P, Jager MJ, Koning RI, Ossendorp F, Cruz LJ. M1-derived extracellular vesicles enhance photodynamic therapy and promote immunological memory in preclinical models of colon cancer. J Nanobiotechnology 2022; 20:252. [PMID: 35658868 PMCID: PMC9164362 DOI: 10.1186/s12951-022-01448-z] [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: 01/28/2022] [Accepted: 05/01/2022] [Indexed: 12/15/2022] Open
Abstract
Extracellular vesicles (EVs) are promising drug carriers of photosensitizers for photodynamic therapy (PDT) in cancer treatment, due to their ability to circulate in blood and enter cells efficiently. The therapeutic potential of EVs has been suggested to depend on the type and physiological state of their cell of origin. However, the effects of deriving EVs from various cells in different physiological states on their antitumor capacity are rarely evaluated. In the present study, we compared the antitumor efficacy of EV-mediated PDT by incorporating the photosensitizer Zinc Phthalocyanine (ZnPc) into EVs from multiple cells sources. ZnPc was incorporated by a direct incubation strategy into EVs derived from immune cells (M1-like macrophages and M2-like macrophages), cancer cells (B16F10 melanoma cancer cells) and external sources (milk). Our data show that all EVs are suitable carriers for ZnPc and enable efficient PDT in vitro in co-culture models and in vivo. We observed that EV-mediated PDT initiates immunogenic cell death through the release and exposure of damage associated molecular patterns (DAMPs) on cancer cells, which subsequently induced dendritic cell (DC) maturation. Importantly, of all ZnPc-EVs tested, in absence of light only M1-ZnPc displayed toxicity to MC38, but not to DC, in monoculture and in co-culture, indicating specificity for cancer over immune cells. In MC38 tumor-bearing mice, only M1-ZnPc induced a tumor growth delay compared to control in absence of light. Interestingly, M1- but not M2-mediated PDT, induced complete responses against MC38 tumors in murine models (100% versus 38% of cases, respectively), with survival of all animals up to at least 60 days post inoculation. Finally, we show that all cured animals are protected from a rechallenge with MC38 cells, suggesting the induction of immunological memory after EV-mediated PDT. Together, our data show the importance of the cell type from which the EVs are obtained and highlight the impact of the immunological state of these cells on the antitumor efficacy of EV-mediated PDT.
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Affiliation(s)
- Ruben V Huis In 't Veld
- Department of Radiology, Leiden University Medical Centre (LUMC), Room C2-187h, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.,Department of Ophthalmology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Pablo Lara
- Department of Radiology, Leiden University Medical Centre (LUMC), Room C2-187h, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Martine J Jager
- Department of Ophthalmology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Roman I Koning
- Department of Cell and Chemical Biology, Section Electron Microscopy, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Ferry Ossendorp
- Department of Immunology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands
| | - Luis J Cruz
- Department of Radiology, Leiden University Medical Centre (LUMC), Room C2-187h, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
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12
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Schechter M, Sharon R. An Emerging Role for Phosphoinositides in the Pathophysiology of Parkinson’s Disease. JOURNAL OF PARKINSON'S DISEASE 2021; 11:1725-1750. [PMID: 34151859 PMCID: PMC8609718 DOI: 10.3233/jpd-212684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Recent data support an involvement of defects in homeostasis of phosphoinositides (PIPs) in the pathophysiology of Parkinson’s disease (PD). Genetic mutations have been identified in genes encoding for PIP-regulating and PIP-interacting proteins, that are associated with familial and sporadic PD. Many of these proteins are implicated in vesicular membrane trafficking, mechanisms that were recently highlighted for their close associations with PD. PIPs are phosphorylated forms of the membrane phospholipid, phosphatidylinositol. Their composition in the vesicle’s membrane of origin, as well as membrane of destination, controls vesicular membrane trafficking. We review the converging evidence that points to the involvement of PIPs in PD. The review describes PD- and PIP-associated proteins implicated in clathrin-mediated endocytosis and autophagy, and highlights the involvement of α-synuclein in these mechanisms.
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Affiliation(s)
- Meir Schechter
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, Jerusalem, Israel
| | - Ronit Sharon
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, Jerusalem, Israel
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13
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Amadeo A, Pizzi S, Comincini A, Modena D, Calogero AM, Madaschi L, Faustini G, Rolando C, Bellucci A, Pezzoli G, Mazzetti S, Cappelletti G. The Association between α-Synuclein and α-Tubulin in Brain Synapses. Int J Mol Sci 2021; 22:ijms22179153. [PMID: 34502063 PMCID: PMC8430732 DOI: 10.3390/ijms22179153] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/14/2022] Open
Abstract
α-synuclein is a small protein that is mainly expressed in the synaptic terminals of nervous tissue. Although its implication in neurodegeneration is well established, the physiological role of α-synuclein remains elusive. Given its involvement in the modulation of synaptic transmission and the emerging role of microtubules at the synapse, the current study aimed at investigating whether α-synuclein becomes involved with this cytoskeletal component at the presynapse. We first analyzed the expression of α-synuclein and its colocalization with α-tubulin in murine brain. Differences were found between cortical and striatal/midbrain areas, with substantia nigra pars compacta and corpus striatum showing the lowest levels of colocalization. Using a proximity ligation assay, we revealed the direct interaction of α-synuclein with α-tubulin in murine and in human brain. Finally, the previously unexplored interaction of the two proteins in vivo at the synapse was disclosed in murine striatal presynaptic boutons through multiple approaches, from confocal spinning disk to electron microscopy. Collectively, our data strongly suggest that the association with tubulin/microtubules might actually be an important physiological function for α-synuclein in the synapse, thus suggesting its potential role in a neuropathological context.
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Affiliation(s)
- Alida Amadeo
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
- Center of Excellence on Neurodegenerative Diseases, University of Milan, Via Celoria 26, 20126 Milano, Italy
- Correspondence: (A.A.); (G.C.); Tel.: +39-025-031-4885 (A.A.); +39-025-031-4752 (G.C.)
| | - Sara Pizzi
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
| | - Alessandro Comincini
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
| | - Debora Modena
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
| | - Alessandra Maria Calogero
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
| | - Laura Madaschi
- UNITECH NOLIMITS, University of Milan, Via Celoria 26, 20133 Milan, Italy;
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy; (G.F.); (A.B.)
| | - Chiara Rolando
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123 Brescia, Italy; (G.F.); (A.B.)
| | - Gianni Pezzoli
- Fondazione Grigioni per il Morbo di Parkinson, Via Zuretti 35, 20125 Milano, Italy;
| | - Samanta Mazzetti
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
- Fondazione Grigioni per il Morbo di Parkinson, Via Zuretti 35, 20125 Milano, Italy;
| | - Graziella Cappelletti
- Department of Biosciences, University of Milan, Via Celoria 26, 20126 Milano, Italy; (S.P.); (A.C.); (D.M.); (A.M.C.); (C.R.); (S.M.)
- Center of Excellence on Neurodegenerative Diseases, University of Milan, Via Celoria 26, 20126 Milano, Italy
- Correspondence: (A.A.); (G.C.); Tel.: +39-025-031-4885 (A.A.); +39-025-031-4752 (G.C.)
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14
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Abstract
α-Synuclein (α-synFL) is central to the pathogenesis of Parkinson's disease (PD), in which its nonfunctional oligomers accumulate and result in abnormal neurotransmission. The normal physiological function of this intrinsically disordered protein is still unclear. Although several previous studies demonstrated α-synFL's role in various membrane fusion steps, they produced conflicting outcomes regarding vesicular secretion. Here, we assess α-synFL's role in directly regulating individual exocytotic release events. We studied the micromillisecond dynamics of single recombinant fusion pores, the crucial kinetic intermediate of membrane fusion that tightly regulates the vesicular secretion in different cell types. α-SynFL accessed v-SNARE within the trans-SNARE complex to form an inhibitory complex. This activity was dependent on negatively charged phospholipids and resulted in decreased open probability of individual pores. The number of trans-SNARE complexes influenced α-synFL's inhibitory action. Regulatory factors that arrest SNARE complexes in different assembly states differentially modulate α-synFL's ability to alter fusion pore dynamics. α-SynFL regulates pore properties in the presence of Munc13-1 and Munc18, which stimulate α-SNAP/NSF-resistant SNARE complex formation. In the presence of synaptotagmin1(syt1), α-synFL contributes with apo-syt1 to act as a membrane fusion clamp, whereas Ca2+•syt1 triggered α-synFL-resistant SNARE complex formation that rendered α-synFL inactive in modulating pore properties. This study reveals a key role of α-synFL in controlling vesicular secretion.
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15
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Khounlo R, Hawk BJD, Khu TM, Yoo G, Lee NK, Pierson J, Shin YK. Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore. Front Cell Dev Biol 2021; 9:663431. [PMID: 34350173 PMCID: PMC8326570 DOI: 10.3389/fcell.2021.663431] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/28/2021] [Indexed: 11/25/2022] Open
Abstract
SNARE-dependent membrane fusion is essential for neurotransmitter release at the synapse. Recently, α-synuclein has emerged as an important regulator for membrane fusion. Misfolded α-synuclein oligomers are potent fusion inhibitors. However, the function of normal α-synuclein has been elusive. Here, we use the single vesicle-to-supported bilayer fusion assay to dissect the role of α-synuclein in membrane fusion. The assay employs 10 kD Rhodamine B-dextran as the content probe that can detect fusion pores larger than ∼6 nm. We find that the SNARE complex alone is inefficient at dilating fusion pores. However, α-synuclein dramatically increases the probability as well as the duration of large pores. When the SNARE-interacting C-terminal region of α-synuclein was truncated, the mutant behaves the same as the wild-type. However, the double proline mutants compromising membrane-binding show significantly reduced effects on fusion pore expansion. Thus, our results suggest that α-synuclein stimulates fusion pore expansion specifically through its membrane binding.
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Affiliation(s)
- Ryan Khounlo
- Yeon-Kyun Shin Lab, Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA, United States
| | - Brenden J D Hawk
- Yeon-Kyun Shin Lab, Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA, United States
| | - Tung-Mei Khu
- Yeon-Kyun Shin Lab, Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA, United States
| | - Gyeongji Yoo
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, South Korea
| | - Nam Ki Lee
- Department of Chemistry, Seoul National University, Seoul, South Korea
| | - Josh Pierson
- Yeon-Kyun Shin Lab, Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA, United States
| | - Yeon-Kyun Shin
- Yeon-Kyun Shin Lab, Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA, United States
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16
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Role of SNAREs in Neurodegenerative Diseases. Cells 2021; 10:cells10050991. [PMID: 33922505 PMCID: PMC8146804 DOI: 10.3390/cells10050991] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/18/2021] [Accepted: 04/20/2021] [Indexed: 02/06/2023] Open
Abstract
Neurodegenerative diseases are pathologies of the central and peripheral nervous systems characterized by loss of brain functions and problems in movement which occur due to the slow and progressive degeneration of cellular elements. Several neurodegenerative diseases are known such as Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis and many studies on the molecular mechanisms underlying these pathologies have been conducted. Altered functions of some key proteins and the presence of intraneuronal aggregates have been identified as responsible for the development of the diseases. Interestingly, the formation of the SNARE complex has been discovered to be fundamental for vesicle fusion, vesicle recycling and neurotransmitter release. Indeed, inhibition of the formation of the SNARE complex, defects in the SNARE-dependent exocytosis and altered regulation of SNARE-mediated vesicle fusion have been associated with neurodegeneration. In this review, the biological aspects of neurodegenerative diseases and the role of SNARE proteins in relation to the onset of these pathologies are described.
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17
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Runwal G, Edwards RH. The Membrane Interactions of Synuclein: Physiology and Pathology. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2021; 16:465-485. [PMID: 33497259 DOI: 10.1146/annurev-pathol-031920-092547] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Specific proteins accumulate in neurodegenerative disease, and human genetics has indicated a causative role for many. In most cases, however, the mechanisms remain poorly understood. Degeneration is thought to involve a gain of abnormal function, although we do not know the normal function of many proteins implicated. The protein α-synuclein accumulates in the Lewy pathology of Parkinson's disease and related disorders, and mutations in α-synuclein cause degeneration, but we have not known its normal function or how it triggers disease. α-Synuclein localizes to presynaptic boutons and interacts with membranes in vitro. Overexpression slows synaptic vesicle exocytosis, and recent data suggest a normal role for the endogenous synucleins in dilation of the exocytic fusion pore. Disrupted membranes also appear surprisingly prominent in Lewy pathology. Synuclein thus interacts with membranes under both physiological and pathological conditions, suggesting that the normal function of synuclein may illuminate its role in degeneration.
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Affiliation(s)
- Gautam Runwal
- Departments of Neurology and Physiology, Graduate Programs in Cell Biology, Biomedical Sciences and Neuroscience, School of Medicine, University of California, San Francisco, California 94143, USA;
| | - Robert H Edwards
- Departments of Neurology and Physiology, Graduate Programs in Cell Biology, Biomedical Sciences and Neuroscience, School of Medicine, University of California, San Francisco, California 94143, USA;
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18
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Liu C, Zhao Y, Xi H, Jiang J, Yu Y, Dong W. The Membrane Interaction of Alpha-Synuclein. Front Cell Neurosci 2021; 15:633727. [PMID: 33746714 PMCID: PMC7969880 DOI: 10.3389/fncel.2021.633727] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/28/2021] [Indexed: 12/12/2022] Open
Abstract
A presynaptic protein closely related to Parkinson's disease (PD), α-synuclein (α-Syn), has been studied extensively regarding its pathogenic mechanisms. As a physiological protein in presynapses, however, α-Syn's physiological function remains unclear. Its location in nerve terminals and effects on membrane fusion also imply its functional role in synaptic transmission, including its possible interaction with high-curvature membranes via its N-terminus and amorphous C-terminus. PD-related mutants that disrupt the membrane interaction (e.g., A30P and G51D) additionally suggest a relationship between α-Syn's pathogenic mechanisms and physiological roles through the membrane binding. Here, we summarize recent research on how α-Syn and its variants interact with membranes and influence synaptic transmission. We list several membrane-related connections between the protein's physiological function and the pathological mechanisms that stand to expand current understandings of α-Syn.
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Affiliation(s)
- Cencen Liu
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Yunfei Zhao
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Huan Xi
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Jie Jiang
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| | - Yang Yu
- Department of Histology and Embryology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Wei Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China.,Department of Neurosurgery, Affiliated Hospital of Southwest Medical University, Luzhou, China.,Neurosurgical Clinical Research Center of Sichuan Province, Luzhou, China
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19
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The docking of synaptic vesicles on the presynaptic membrane induced by α-synuclein is modulated by lipid composition. Nat Commun 2021; 12:927. [PMID: 33568632 PMCID: PMC7876145 DOI: 10.1038/s41467-021-21027-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/07/2021] [Indexed: 12/15/2022] Open
Abstract
α-Synuclein (αS) is a presynaptic disordered protein whose aberrant aggregation is associated with Parkinson’s disease. The functional role of αS is still debated, although it has been involved in the regulation of neurotransmitter release via the interaction with synaptic vesicles (SVs). We report here a detailed characterisation of the conformational properties of αS bound to the inner and outer leaflets of the presynaptic plasma membrane (PM), using small unilamellar vesicles. Our results suggest that αS preferentially binds the inner PM leaflet. On the basis of these studies we characterise in vitro a mechanism by which αS stabilises, in a concentration-dependent manner, the docking of SVs on the PM by establishing a dynamic link between the two membranes. The study then provides evidence that changes in the lipid composition of the PM, typically associated with neurodegenerative diseases, alter the modes of binding of αS, specifically in a segment of the sequence overlapping with the non-amyloid component region. Taken together, these results reveal how lipid composition modulates the interaction of αS with the PM and underlie its functional and pathological behaviours in vitro. α-Synuclein is a presynaptic protein whose aberrant aggregation is associated with Parkinson’s disease. Here, the authors show how αSynuclein-induced docking of synaptic vesicles is modulated by the lipid composition changes typically observed in neurodegeneration using an in vitro system.
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20
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Schechter M, Atias M, Abd Elhadi S, Davidi D, Gitler D, Sharon R. α-Synuclein facilitates endocytosis by elevating the steady-state levels of phosphatidylinositol 4,5-bisphosphate. J Biol Chem 2020; 295:18076-18090. [PMID: 33087443 PMCID: PMC7939461 DOI: 10.1074/jbc.ra120.015319] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/08/2020] [Indexed: 12/12/2022] Open
Abstract
α-Synuclein (α-Syn) is a protein implicated in the pathogenesis of Parkinson's disease (PD). It is an intrinsically disordered protein that binds acidic phospholipids. Growing evidence supports a role for α-Syn in membrane trafficking, including, mechanisms of endocytosis and exocytosis, although the exact role of α-Syn in these mechanisms is currently unclear. Here we investigate the associations of α-Syn with the acidic phosphoinositides (PIPs), phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2). Our results show that α-Syn colocalizes with PIP2 and the phosphorylated active form of the clathrin adaptor protein 2 (AP2) at clathrin-coated pits. Using endocytosis of transferrin as an indicator for clathrin-mediated endocytosis (CME), we find that α-Syn involvement in endocytosis is specifically mediated through PI(4,5)P2 levels on the plasma membrane. In accord with their effects on PI(4,5)P2 levels, the PD associated A30P, E46K, and A53T mutations in α-Syn further enhance CME in neuronal and nonneuronal cells. However, lysine to glutamic acid substitutions at the KTKEGV repeat domain of α-Syn, which interfere with phospholipid binding, are ineffective in enhancing CME. We further show that the rate of synaptic vesicle (SV) endocytosis is differentially affected by the α-Syn mutations and associates with their effects on PI(4,5)P2 levels, however, with the exception of the A30P mutation. This study provides evidence for a critical involvement of PIPs in α-Syn-mediated membrane trafficking.
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Affiliation(s)
- Meir Schechter
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Merav Atias
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Suaad Abd Elhadi
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Dana Davidi
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Daniel Gitler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ronit Sharon
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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21
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Wu K, Li D, Xiu P, Ji B, Diao J. O-GlcNAcylation inhibits the oligomerization of alpha-synuclein by declining intermolecular hydrogen bonds through a steric effect. Phys Biol 2020; 18:016002. [DOI: 10.1088/1478-3975/abb6dc] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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22
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Melland H, Carr EM, Gordon SL. Disorders of synaptic vesicle fusion machinery. J Neurochem 2020; 157:130-164. [PMID: 32916768 DOI: 10.1111/jnc.15181] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/20/2020] [Accepted: 08/26/2020] [Indexed: 12/11/2022]
Abstract
The revolution in genetic technology has ushered in a new age for our understanding of the underlying causes of neurodevelopmental, neuromuscular and neurodegenerative disorders, revealing that the presynaptic machinery governing synaptic vesicle fusion is compromised in many of these neurological disorders. This builds upon decades of research showing that disturbance to neurotransmitter release via toxins can cause acute neurological dysfunction. In this review, we focus on disorders of synaptic vesicle fusion caused either by toxic insult to the presynapse or alterations to genes encoding the key proteins that control and regulate fusion: the SNARE proteins (synaptobrevin, syntaxin-1 and SNAP-25), Munc18, Munc13, synaptotagmin, complexin, CSPα, α-synuclein, PRRT2 and tomosyn. We discuss the roles of these proteins and the cellular and molecular mechanisms underpinning neurological deficits in these disorders.
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Affiliation(s)
- Holly Melland
- The Florey Institute of Neuroscience and Mental Health, Melbourne Dementia Research Centre, The University of Melbourne, Melbourne, Vic., Australia
| | - Elysa M Carr
- The Florey Institute of Neuroscience and Mental Health, Melbourne Dementia Research Centre, The University of Melbourne, Melbourne, Vic., Australia
| | - Sarah L Gordon
- The Florey Institute of Neuroscience and Mental Health, Melbourne Dementia Research Centre, The University of Melbourne, Melbourne, Vic., Australia
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23
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Dash BP, Naumann M, Sterneckert J, Hermann A. Genome Wide Analysis Points towards Subtype-Specific Diseases in Different Genetic Forms of Amyotrophic Lateral Sclerosis. Int J Mol Sci 2020; 21:E6938. [PMID: 32967368 PMCID: PMC7555318 DOI: 10.3390/ijms21186938] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/15/2022] Open
Abstract
Amyotropic lateral sclerosis (ALS) is a lethally progressive and irreversible neurodegenerative disease marked by apparent death of motor neurons present in the spinal cord, brain stem and motor cortex. While more and more gene mutants being established for genetic ALS, the vast majority suffer from sporadic ALS (>90%). It has been challenging, thus, to model sporadic ALS which is one reason why the underlying pathophysiology remains elusive and has stalled the development of therapeutic strategies of this progressive motor neuron disease. To further unravel these pathological signaling pathways, human induced pluripotent stem cell (hiPSCs)-derived motor neurons (MNs) from FUS- and SOD1 ALS patients and healthy controls were systematically compared to independent published datasets. Here through this study we created a gene profile of ALS by analyzing the DEGs, the Kyoto encyclopedia of Genes and Genomes (KEGG) pathways, the interactome and the transcription factor profiles (TF) that would identify altered molecular/functional signatures and their interactions at both transcriptional (mRNAs) and translational levels (hub proteins and TFs). Our findings suggest that FUS and SOD1 may develop from dysregulation in several unique pathways and herpes simplex virus (HSV) infection was among the topmost predominant cellular pathways connected to FUS and not to SOD1. In contrast, SOD1 is mainly characterized by alterations in the metabolic pathways and alterations in the neuroactive-ligand-receptor interactions. This suggests that different genetic ALS forms are singular diseases rather than part of a common spectrum. This is important for patient stratification clearly pointing towards the need for individualized medicine approaches in ALS.
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Affiliation(s)
- Banaja P. Dash
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany; (B.P.D.); (M.N.)
| | - Marcel Naumann
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany; (B.P.D.); (M.N.)
| | - Jared Sterneckert
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01069 Dresden, Germany;
| | - Andreas Hermann
- Translational Neurodegeneration Section “Albrecht-Kossel”, Department of Neurology, University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany; (B.P.D.); (M.N.)
- German Center for Neurodegenerative Diseases (DZNE) Rostock/Greifswald, 18147 Rostock, Germany
- Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, 18147 Rostock, Germany
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24
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Şengül B, Dursun E, Verkhratsky A, Gezen-Ak D. Overexpression of α-Synuclein Reorganises Growth Factor Profile of Human Astrocytes. Mol Neurobiol 2020; 58:184-203. [PMID: 32914394 DOI: 10.1007/s12035-020-02114-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 09/01/2020] [Indexed: 12/26/2022]
Abstract
Misfolding and accumulation of aberrant α-synuclein in the brain is associated with the distinct class of neurodegenerative diseases known as α-synucleinopathies, which include Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. Pathological changes in astrocytes contribute to all neurological disorders, and astrocytes are reported to possess α-synuclein inclusions in the context of α-synucleinopathies. Astrocytes are known to express and secrete numerous growth factors, which are fundamental for neuroprotection, synaptic connectivity and brain metabolism; changes in growth factor secretion may contribute to pathobiology of neurological disorders. Here we analysed the effect of α-synuclein overexpression in cultured human astrocytes on growth factor expression and release. For this purpose, the intracellular and secreted levels of 33 growth factors (GFs) and 8 growth factor receptors (GFRs) were analysed in cultured human astrocytes by chemiluminescence-based western/dot blot. Overexpression of human α-synuclein in cultured foetal human astrocytes significantly changes the profile of GF production and secretion. We found that human astrocytes express and secrete FGF2, FGF6, EGF, IGF1, AREG, IGFBP2, IGFBP4, VEGFD, PDGFs, KITLG, PGF, TGFB3 and NTF4. Overexpression of human α-synuclein significantly modified the profile of GF production and secretion, with particularly strong changes in EGF, PDGF, VEGF and their receptors as well as in IGF-related proteins. Bioinformatics analysis revealed possible interactions between α-synuclein and EGFR and GDNF, as well as with three GF receptors, EGFR, CSF1R and PDGFRB.
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Affiliation(s)
- Büşra Şengül
- Brain and Neurodegenerative Disorders Research Laboratories, Department of Medical Biology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Erdinç Dursun
- Brain and Neurodegenerative Disorders Research Laboratories, Department of Medical Biology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey.,Department of Neuroscience, Institute of Neurological Sciences, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK. .,Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Duygu Gezen-Ak
- Brain and Neurodegenerative Disorders Research Laboratories, Department of Medical Biology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey.
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25
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Cai B, Liu J, Zhao Y, Xu X, Bu B, Li D, Zhang L, Dong W, Ji B, Diao J. Single-vesicle imaging quantifies calcium's regulation of nanoscale vesicle clustering mediated by α-synuclein. MICROSYSTEMS & NANOENGINEERING 2020; 6:38. [PMID: 34567651 PMCID: PMC8433175 DOI: 10.1038/s41378-020-0147-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/18/2020] [Accepted: 02/03/2020] [Indexed: 06/13/2023]
Abstract
Although numerous studies have shown that the protein α-synuclein (α-Syn) plays a central role in Parkinson's disease, dementia with Lewy bodies, and other neurodegenerative diseases, the protein's physiological function remains poorly understood. Furthermore, despite recent reports suggesting that, under the influence of Ca2+, α-Syn can interact with synaptic vesicles, the mechanisms underlying that interaction are far from clear. Thus, we used single-vesicle imaging to quantify the extent to which Ca2+ regulates nanoscale vesicle clustering mediated by α-Syn. Our results revealed not only that vesicle clustering required α-Syn to bind to anionic lipid vesicles, but also that different concentrations of Ca2+ exerted different effects on how α-Syn induced vesicle clustering. In particular, low concentrations of Ca2+ inhibited vesicle clustering by blocking the electrostatic interaction between the lipid membrane and the N terminus of α-Syn, whereas high concentrations promoted vesicle clustering, possibly due to the electrostatic interaction between Ca2+ and the negatively charged lipids that is independent of α-Syn. Taken together, our results provide critical insights into α-Syn's physiological function, and how Ca2+ regulates vesicle clustering mediated by α-Syn.
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Affiliation(s)
- Bin Cai
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267 USA
| | - Jie Liu
- Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing, 100081 China
| | - Yunfei Zhao
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000 China
| | - Xiangyu Xu
- Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing, 100081 China
| | - Bing Bu
- Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164 China
| | - Dechang Li
- Institute of Applied Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027 China
| | - Lei Zhang
- Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter (Ministry of Education), School of Science, Xi’an Jiaotong University, Xi’an, 710049 China
| | - Wei Dong
- Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan 646000 China
| | - Baohua Ji
- Institute of Applied Mechanics, Department of Engineering Mechanics, Zhejiang University, Hangzhou, 310027 China
- Beijing Advanced Innovation Center for Biomedical Engineering, Beijing, 100191 China
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267 USA
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26
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Meir S, Merav A, Suaad AE, Dana D, Daniel G, Ronit S. α-Synuclein facilitates endocytosis by elevating the steady-state levels of phosphatidylinositol 4,5-bisphosphate.. [DOI: 10.1101/2020.06.18.158709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Abstractα-Synuclein (α-Syn) is a protein implicated in the pathogenesis of Parkinson’s disease (PD). It is an intrinsically disordered protein that binds acidic phospholipids. Growing evidence supports a role for α-Syn in membrane trafficking, including, mechanisms of endocytosis and exocytosis, although the exact role of α-Syn in these mechanisms is currently unclear. Here we have investigated the role of α-Syn in membrane trafficking through its association with acidic phosphoinositides (PIPs), such as phosphatidylinositol 4,5-bisphosphate (PI4,5P2) and phosphatidylinositol 3,4-bisphosphate (PI3,4P2). Our results show that α-Syn colocalizes with PIP2 and the phosphorylated active form of the clathrin adaptor AP2 at clathrin-coated pits. Using endocytosis of transferrin, an indicator of clathrin mediated endocytosis (CME), we find that α-Syn involvement in endocytosis is specifically mediated through PI4,5P2 levels. We further show that the rate of synaptic vesicle (SV) endocytosis is differentially affected by α-Syn mutations. In accord with their effects on PI4,5P2 levels at the plasma membrane, the PD associated E46K and A53T mutations further enhance SV endocytosis. However, neither A30P mutation, nor Lysine to Glutamic acid substitutions at the KTKEGV repeat domain of α-Syn, that interfere with phospholipid binding, affect SV endocytosis. This study provides evidence for a critical involvement of PIPs in α-Syn-mediated membrane trafficking.Significance Statementα-Synuclein (α-Syn) protein is known for its causative role in Parkinson’s disease. α-Syn is normally involved in mechanisms of membrane trafficking, including endocytosis, exocytosis and synaptic vesicles cycling. However, a certain degree of controversy regarding the exact role of α-Syn in these mechanisms persists. Here we show that α-Syn acts to increase plasma membrane levels PI4,5P2 and PI3,4P2 to facilitate clathrin mediated and synaptic vesicles endocytosis. Based on the results, we suggest that α-Syn interactions with the acidic phosphoinositides facilitate a shift in their homeostasis to support endocytosis.
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Zhao X, Wu D, Ma X, Wang J, Hou W, Zhang W. Exosomes as drug carriers for cancer therapy and challenges regarding exosome uptake. Biomed Pharmacother 2020; 128:110237. [PMID: 32470747 DOI: 10.1016/j.biopha.2020.110237] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 12/20/2022] Open
Abstract
With the development of biomedicine, exosomes are rapidly developing as a new therapy for tumors. As biological carriers, exosomes possess biological activity and can transport their contents between cells. The contents are natural or artificially loaded with biomolecules or chemical drugs. Exosomes deliver biomolecules or chemical drugs into the pathological sites of recipient, which can effectively inhibit the progression of tumors. However, the treatments of tumors through the delivery of exosomes are not sufficiently accurate or efficient, and various challenges need to be overcome. Exosomes from different cell sources possess different characteristics, as well as different specificity for various cells. In the future, for the promotion and application of exosomes, it is of great significance to understand how to select appropriate exosomes loaded with biomolecules or chemical drugs for different tumors types, and how to deliver exosomes to recipient cells accurately and efficiently. This review introduces the application and challenges of exosomes as delivery carriers in tumors.
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Affiliation(s)
- Xiaoyin Zhao
- Lab of Chemical Biology and Molecular Drug Design, Institute of Drug Development & Chemical Biology, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China.
| | - Dongliang Wu
- Lab of Chemical Biology and Molecular Drug Design, Institute of Drug Development & Chemical Biology, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Xudong Ma
- Lab of Chemical Biology and Molecular Drug Design, Institute of Drug Development & Chemical Biology, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Jiale Wang
- Lab of Chemical Biology and Molecular Drug Design, Institute of Drug Development & Chemical Biology, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Wenjun Hou
- Lab of Chemical Biology and Molecular Drug Design, Institute of Drug Development & Chemical Biology, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Wen Zhang
- Lab of Chemical Biology and Molecular Drug Design, Institute of Drug Development & Chemical Biology, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China.
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Wilson H, Pagano G, de Natale ER, Mansur A, Caminiti SP, Polychronis S, Middleton LT, Price G, Schmidt KF, Gunn RN, Rabiner EA, Politis M. Mitochondrial Complex 1, Sigma 1, and Synaptic Vesicle 2A in Early Drug-Naive Parkinson's Disease. Mov Disord 2020; 35:1416-1427. [PMID: 32347983 DOI: 10.1002/mds.28064] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Dysfunction of mitochondrial energy generation may contribute to neurodegeneration, leading to synaptic loss in Parkinson's disease (PD). The objective of this study was to find cross-sectional and longitudinal changes in PET markers of synaptic vesicle protein 2A, sigma 1 receptor, and mitochondrial complex 1 in drug-naive PD patients. METHODS Twelve early drug-naive PD patients and 16 healthy controls underwent a 3-Tesla MRI and PET imaging to quantify volume of distribution of [11 C]UCB-J, [11 C]SA-4503, and [18 F]BCPP-EF for synaptic vesicle protein 2A, sigma 1 receptor, and mitochondrial complex 1, respectively. Nine PD patients completed approximately 1-year follow-up assessments. RESULTS Reduced [11 C]UCB-J volume of distribution in the caudate, putamen, thalamus, brain stem, and dorsal raphe and across cortical regions was observed in drug-naive PD patients compared with healthy controls. [11 C]UCB-J volume of distribution was reduced in the locus coeruleus and substantia nigra but did not reach statistical significance. No significant differences were found in [11 C]SA-4503 and [18 F]BCPP-EF volume of distribution in PD compared with healthy controls. Lower brain stem [11 C]UCB-J volume of distribution correlated with Movement Disorder Society Unified Parkinson's Disease Rating Scale part III and total scores. No significant longitudinal changes were identified in PD patients at follow-up compared with baseline. CONCLUSIONS Our findings represent the first in vivo evidence of mitochondrial, endoplasmic reticulum, and synaptic dysfunction in drug-naive PD patients. Synaptic dysfunction likely occurs early in disease pathophysiology and has relevance to symptomatology. Mitochondrial complex 1 and sigma 1 receptor pathology warrants further investigations in PD. Studies in larger cohorts with longer follow-up will determine the validity of these PET markers to track disease progression. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Heather Wilson
- Neurodegeneration Imaging Group, University of Exeter Medical School, London, UK.,Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Gennaro Pagano
- Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Edoardo Rosario de Natale
- Neurodegeneration Imaging Group, University of Exeter Medical School, London, UK.,Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Ayla Mansur
- Invicro, Centre for Imaging Sciences, Hammersmith Hospital, London, UK.,Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Silvia Paola Caminiti
- Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Sotirios Polychronis
- Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Lefkos T Middleton
- School of Public Health, Imperial College London, UK.,Public Health Directorate, Imperial College NHS Healthcare Trust, London, UK.,MINDMAPS Consortium, London, UK
| | - Geraint Price
- School of Public Health, Imperial College London, UK.,MINDMAPS Consortium, London, UK
| | | | - Roger N Gunn
- Invicro, Centre for Imaging Sciences, Hammersmith Hospital, London, UK.,Division of Brain Sciences, Department of Medicine, Imperial College London, UK.,MINDMAPS Consortium, London, UK
| | - Eugenii A Rabiner
- Invicro, Centre for Imaging Sciences, Hammersmith Hospital, London, UK.,MINDMAPS Consortium, London, UK.,Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Marios Politis
- Neurodegeneration Imaging Group, University of Exeter Medical School, London, UK.,Neurodegeneration Imaging Group, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.,MINDMAPS Consortium, London, UK
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Bhasne K, Jain N, Karnawat R, Arya S, Majumdar A, Singh A, Mukhopadhyay S. Discerning Dynamic Signatures of Membrane-Bound α-Synuclein Using Site-Specific Fluorescence Depolarization Kinetics. J Phys Chem B 2020; 124:708-717. [PMID: 31917569 DOI: 10.1021/acs.jpcb.9b09118] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
α-Synuclein is an intrinsically disordered protein that adopts an α-helical structure upon binding to the negatively charged lipid membrane. Binding-induced conformational change of α-synuclein plays a crucial role in the regulation of synaptic plasticity. In this work, we utilized the fluorescence depolarization kinetics methodology to gain the site-specific dynamical insights into the membrane-bound α-synuclein. We took advantage of the nonoccurrence of Cys in α-synuclein and created single-Cys variants at different sites for us to be able to label it with a thiol-active fluorophore. Our fluorescence depolarization results reveal the presence of three dynamically distinct types of motions of α-synuclein on POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol)) small unilamellar vesicles (SUVs): (i) the (local) wobbling-in-cone motion of the fluorophore on the subnanosecond timescale, (ii) the backbone segmental mobility on the nanosecond timescale, and (iii) a slow depolarization component with a characteristic long rotational correlation time (∼60 ns) that is independent of the residue position. This characteristic timescale could potentially arise due to global tumbling of the protein-membrane complex, the global reorientation of only the protein within the membrane, and/or the translation diffusion of the protein on the curved membrane surface that could result in fluorescence depolarization due to the angular displacement of the transition dipole. In order to discern the molecular origin of the characteristic long rotational correlation time, we then carried our depolarization experiments varying the curvature of the membrane and varying the binding affinity by changing the lipid headgroup. These experiments revealed that the long rotational correlation time primarily arises due to the translational diffusion of α-synuclein on the curved membrane surface with a diffusion coefficient of ∼8.7 × 10-10 m2/s. The site-specific fluorescence depolarization methodology will find broad application in quantifying diffusion of a wide range of membrane-associated proteins involved in functions and diseases.
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Affiliation(s)
- Karishma Bhasne
- Centre for Protein Science, Design and Engineering , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India.,Department of Biological Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
| | - Neha Jain
- Department of Biological Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
| | - Rishabh Karnawat
- Department of Biological Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
| | - Shruti Arya
- Centre for Protein Science, Design and Engineering , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India.,Department of Chemical Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
| | - Anupa Majumdar
- Centre for Protein Science, Design and Engineering , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India.,Department of Biological Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
| | - Anubhuti Singh
- Department of Chemical Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India.,Department of Biological Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India.,Department of Chemical Sciences , Indian Institute of Science Education and Research (IISER) , Mohali 140306 , India
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30
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Swaminathan M, Fung C, Finkelstein DI, Bornstein JC, Foong JPP. α-Synuclein Regulates Development and Function of Cholinergic Enteric Neurons in the Mouse Colon. Neuroscience 2019; 423:76-85. [PMID: 31705886 DOI: 10.1016/j.neuroscience.2019.10.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023]
Abstract
Alpha-Synuclein (α-Syn) is expressed in the central nervous system and the nervous system of the gut (enteric nervous system, ENS), and is well known to be the major constituent of Lewy bodies which are the hallmark of Parkinson's disease. Gastrointestinal disorders frequently manifest several years before motor deficits develop in Parkinson's patients. Despite extensive research on pathological rodent models, the physiological role of α-Syn in the normal ENS is unclear hampering analysis of its neuropathology. We compared the ENS in colons of α-Syn-knockout (α-Syn KO) and wild-type mice using immunohistochemistry and calcium-imaging of responses to synaptic input. We found that α-Syn is predominantly expressed in cholinergic varicosities, which contain vesicular acetylcholine transporter. α-Syn KO mice had higher enteric neuron density and a larger proportion of cholinergic neurons, notably those containing calretinin, demonstrating a role for α-Syn in regulating development of these neurons. Moreover, α-Syn deletion enhanced the amplitude of synaptically activated [Ca2+]i transients that are primarily mediated by acetylcholine activating nicotinic receptors suggesting that α-Syn modulates the availability of acetylcholine in enteric nerve terminals.
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Affiliation(s)
- M Swaminathan
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - C Fung
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - D I Finkelstein
- The Florey Institute of Neuroscience and Mental Health, Kenneth Myer Building, The University of Melbourne, Parkville, VIC, Australia
| | - J C Bornstein
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - J P P Foong
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia.
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31
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Pei Y, Maitta RW. Alpha synuclein in hematopoiesis and immunity. Heliyon 2019; 5:e02590. [PMID: 31692680 PMCID: PMC6806402 DOI: 10.1016/j.heliyon.2019.e02590] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/13/2019] [Accepted: 10/02/2019] [Indexed: 12/15/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative condition and intracellular deposition of Lewy bodies in the substantia nigra (SN), which can cause dopaminergic neuronal death, is the hallmark of this syndrome. α-synuclein (syn) is a small protein expressed mainly in neurons but can also be found in a number of tissues. It can be present as a soluble monomer under normal physiological conditions, but can be toxic in its oligomeric or fibrillary forms. Most of the available literature has focused on the effects of α-syn pathology in the mechanisms leading to PD. However, the normal functions of α-syn still remain to be fully elucidated. Notably, α-syn in the hematopoietic system seems to mediate important functions as indicated by anemia and incomplete cell maturation when this protein is absent. This review will summarize basic genetic and structural findings, and critical information that suggests an essential role of α-syn in the development and activation of the hematopoietic system and immunity.
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Affiliation(s)
- Yu Pei
- University Hospitals Cleveland Medical Center, Cleveland, OH, United States
| | - Robert W. Maitta
- University Hospitals Cleveland Medical Center, Cleveland, OH, United States
- Case Western Reserve University School of Medicine, Cleveland, OH, United States
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32
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Sulzer D, Edwards RH. The physiological role of α-synuclein and its relationship to Parkinson's Disease. J Neurochem 2019; 150:475-486. [PMID: 31269263 PMCID: PMC6707892 DOI: 10.1111/jnc.14810] [Citation(s) in RCA: 190] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/03/2019] [Accepted: 06/28/2019] [Indexed: 12/15/2022]
Abstract
The protein α-synuclein has a central role in the pathogenesis of Parkinson's disease (PD). In this review, we discuss recent results concerning its primary function, which appears to be on cell membranes. The pre-synaptic location of synuclein has suggested a role in neurotransmitter release and it apparently associates with synaptic vesicles because of their high curvature. Indeed, synuclein over-expression inhibits synaptic vesicle exocytosis. However, loss of synuclein has not yet been shown to have a major effect on synaptic transmission. Consistent with work showing that synuclein can promote as well as sense membrane curvature, recent analysis of synuclein triple knockout mice now shows that synuclein accelerates dilation of the exocytic fusion pore. This form of regulation affects primarily the release of slowly discharged lumenal cargo such as neural peptides, but presumably also contributes to maintenance of the release site. This article is part of the Special Issue "Synuclein".
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Affiliation(s)
- David Sulzer
- Departments of Psychiatry, Neurology and Pharmacology, Columbia University Medical Center, New York State Psychiatric Institute
| | - Robert H Edwards
- Departments of Neurology and Physiology, Graduate Programs in Cell Biology, Biomedical Sciences and Neuroscience, UCSF School of Medicine
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33
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Cai B, Yu L, Sharum SR, Zhang K, Diao J. Single-vesicle measurement of protein-induced membrane tethering. Colloids Surf B Biointerfaces 2019; 177:267-273. [PMID: 30769228 DOI: 10.1016/j.colsurfb.2019.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 01/28/2019] [Accepted: 02/04/2019] [Indexed: 12/30/2022]
Abstract
Functions of the proteins involved in membrane tethering, a crucial step in membrane trafficking, remain elusive due to the lack of effective tools to investigate protein-lipid interaction. To address this challenge, we introduce a method to study protein-induced membrane tethering via in vitro reconstitution of lipid vesicles, including detailed steps from the preparation of the PEGylated slides to the imaging of single vesicles. Furthermore, we demonstrate the measurement of protein-vesicle interaction in tethered vesicle pairs using two representative proteins, the cytoplasmic domain of synaptotagmin-1 (C2AB) and α-synuclein. Results from Förster (fluorescence) resonance energy transfer (FRET) reveal that membrane tethering is distinguished from membrane fusion. Single-vesicle measurement also allows for assessment of dose-dependent effects of proteins and ions on membrane tethering. We envision that the continuous development of advanced techniques in the single-vesicle measurement will enable the investigation of complex protein-membrane interactions in live cells or tissues.
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Affiliation(s)
- Bin Cai
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH 45267, USA; Research Center for Nano-Biomaterial, Analytical & Testing Center, Sichuan University, Chengdu 610064, China
| | - Luning Yu
- Department of Physics, University of Cincinnati, Cincinnati, OH 45221, USA
| | - Savanna R Sharum
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Kai Zhang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati, Cincinnati, OH 45267, USA.
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Hawk BJD, Khounlo R, Shin YK. Alpha-Synuclein Continues to Enhance SNARE-Dependent Vesicle Docking at Exorbitant Concentrations. Front Neurosci 2019; 13:216. [PMID: 30949020 PMCID: PMC6437117 DOI: 10.3389/fnins.2019.00216] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 02/25/2019] [Indexed: 11/18/2022] Open
Abstract
Recently, Parkinson’s disease-associated α-synuclein (αS) has emerged as an important regulator for SNARE-dependent vesicle fusion. However, it is controversial if excessive accumulation of αS, even in the absence of aggregation, impairs neurotransmission. Here we use a single vesicle fusion assay with ms time resolution capable of dissecting the impact of αS on each step of membrane fusion. Unlike the previous results from various in vitro, cellular, and in vivo studies, we find that non-aggregated αS promotes vesicle merger even at exorbitant concentrations. The enhancement has been seen as much as 13 fold. Delving into the kinetics of the intermediate states for vesicle fusion reveals that αS stimulates vesicle docking without altering the dynamics of bilayer merger (lipid mixing). However, minute amounts of soluble aggregated species abolish SNARE-dependent bilayer merger completely. Thus, the results show that excessive accumulation of non-aggregated αS may not be toxic for neurotransmitter release.
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Affiliation(s)
- Brenden J D Hawk
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Ryan Khounlo
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Yeon-Kyun Shin
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
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35
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Abstract
The past few years have resulted in an increased awareness and recognition of the prevalence and roles of intrinsically disordered proteins and protein regions (IDPs and IDRs, respectively) in synaptic vesicle trafficking and exocytosis and in overall synaptic organization. IDPs and IDRs constitute a class of proteins and protein regions that lack stable tertiary structure, but nevertheless retain biological function. Their significance in processes such as cell signaling is now well accepted, but their pervasiveness and importance in other areas of biology are not as widely appreciated. Here, we review the prevalence and functional roles of IDPs and IDRs associated with the release and recycling of synaptic vesicles at nerve terminals, as well as with the architecture of these terminals. We hope to promote awareness, especially among neuroscientists, of the importance of this class of proteins in these critical pathways and structures. The examples discussed illustrate some of the ways in which the structural flexibility conferred by intrinsic protein disorder can be functionally advantageous in the context of cellular trafficking and synaptic function.
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Affiliation(s)
- David Snead
- From the Department of Biochemistry, Weill Cornell Medicine, New York, New York 10021
| | - David Eliezer
- From the Department of Biochemistry, Weill Cornell Medicine, New York, New York 10021
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36
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Huang M, Wang B, Li X, Fu C, Wang C, Kang X. α-Synuclein: A Multifunctional Player in Exocytosis, Endocytosis, and Vesicle Recycling. Front Neurosci 2019; 13:28. [PMID: 30745863 PMCID: PMC6360911 DOI: 10.3389/fnins.2019.00028] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 01/14/2019] [Indexed: 11/22/2022] Open
Abstract
α-synuclein (α-Syn) is a presynaptic enriched protein involved in the pathogenesis of Parkinson’s disease. However, the physiological roles of α-Syn remain poorly understood. Recent studies have indicated a critical role of α-Syn in the sensing and generation of membrane curvature during vesicular exocytosis and endocytosis. It has been known to modulate the assembly of SNARE complex during exocytosis including vesicle docking, priming and fusion steps. Growing evidence suggests that α-Syn also plays critical roles in the endocytosis of synaptic vesicles. It also modulates the availability of releasable vesicles by promoting synaptic vesicles clustering. Here, we provide an overview of recent progresses in understanding the function of α-Syn in the regulation of exocytosis, endocytosis, and vesicle recycling under physiological and pathological conditions.
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Affiliation(s)
- Mingzhu Huang
- School of Life Sciences, Liaocheng University, Liaocheng, China.,Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Bianbian Wang
- School of Life Sciences, Liaocheng University, Liaocheng, China.,Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xiaopeng Li
- School of Life Sciences, Liaocheng University, Liaocheng, China.,Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Chongluo Fu
- School of Life Sciences, Liaocheng University, Liaocheng, China
| | - Changhe Wang
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xinjiang Kang
- School of Life Sciences, Liaocheng University, Liaocheng, China.,Key Laboratory of Medical Electrophysiology of Ministry of Education and Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
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37
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Biochemical studies of membrane fusion at the single-particle level. Prog Lipid Res 2019; 73:92-100. [PMID: 30611882 DOI: 10.1016/j.plipres.2019.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 01/01/2019] [Accepted: 01/02/2019] [Indexed: 01/21/2023]
Abstract
To study membrane fusion mediated by synaptic proteins, proteoliposomes have been widely used for in vitro ensemble measurements with limited insights into the fusion mechanism. Single-particle techniques have proven to be powerful in overcoming the limitations of traditional ensemble methods. Here, we summarize current single-particle methods in biophysical and biochemical studies of fusion mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and other synaptic proteins, together with their advantages and limitations.
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38
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Living in Promiscuity: The Multiple Partners of Alpha-Synuclein at the Synapse in Physiology and Pathology. Int J Mol Sci 2019; 20:ijms20010141. [PMID: 30609739 PMCID: PMC6337145 DOI: 10.3390/ijms20010141] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 12/24/2018] [Accepted: 12/26/2018] [Indexed: 12/18/2022] Open
Abstract
Alpha-synuclein (α-syn) is a small protein that, in neurons, localizes predominantly to presynaptic terminals. Due to elevated conformational plasticity, which can be affected by environmental factors, in addition to undergoing disorder-to-order transition upon interaction with different interactants, α-syn is counted among the intrinsically disordered proteins (IDPs) family. As with many other IDPs, α-syn is considered a hub protein. This function is particularly relevant at synaptic sites, where α-syn is abundant and interacts with many partners, such as monoamine transporters, cytoskeletal components, lipid membranes, chaperones and synaptic vesicles (SV)-associated proteins. These protein–protein and protein–lipid membrane interactions are crucial for synaptic functional homeostasis, and alterations in α-syn can cause disruption of this complex network, and thus a failure of the synaptic machinery. Alterations of the synaptic environment or post-translational modification of α-syn can induce its misfolding, resulting in the formation of oligomers or fibrillary aggregates. These α-syn species are thought to play a pathological role in neurodegenerative disorders with α-syn deposits such as Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA), which are referred to as synucleinopathies. Here, we aim at revising the complex and promiscuous role of α-syn at synaptic terminals in order to decipher whether α-syn molecular interactants may influence its conformational state, contributing to its aggregation, or whether they are just affected by it.
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Abstract
This chapter expounds the single vesicle-vesicle fluorescence resonance energy transfer (FRET) measurement to study the membrane fusion mediated by SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. The formation of a four-α-helix bundle of SNARE proteins can drive two membranes to a close proximity for fusion. Through single-molecule FRET-based microscopy, the lipid-mixing process at the single-vesicle level can be tracked in real time. This reconstitution system is applicable to study the molecular mechanism of SNAREs during different membrane fusion stages, such as docking, hemifusion, and full fusion. Four main parts are described in this chapter, including SNARE reconstitution, imaging preparation, data collection, and analysis.
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Affiliation(s)
- Yachong Hu
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Zhiqi Tian
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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40
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Presynaptic Dysfunction by Familial Factors in Parkinson Disease. Int Neurourol J 2018; 22:S115-121. [PMID: 30396260 PMCID: PMC6234725 DOI: 10.5213/inj.1836216.108] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 10/10/2018] [Indexed: 12/28/2022] Open
Abstract
Parkinson disease (PD) is the second most prevalent neurodegenerative disorder after Alzheimer disease. The loss of specific brain area, the substantia nigra pars compacta is known as a major etiology, however it is not fully understood how this neurodegeneration is initiated and what precisely causes this disease. As one aspect of pathophysiology for PD, synaptic dysfunction (synaptopathy) is thought to be an earlier appearance for neurodegeneration. In addition, some of the familial factors cumulatively exhibit that these factors such as α-synuclein, leucine-rich repeat kinase 2, parkin, PTEN-induced kinase 1, and DJ-1 are involved in the regulation of synaptic function and missense mutants of familial factors found in PD-patient show dysregulation of synaptic functions. In this review, we have discussed the physiological function of these genetic factors in presynaptic terminal and how dysregulation of presynaptic function by genetic factors might be related to the pathogenesis of Parkinson disease.
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41
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Agliardi C, Guerini FR, Zanzottera M, Riboldazzi G, Zangaglia R, Sturchio A, Casali C, Di Lorenzo C, Minafra B, Nemni R, Clerici M. SNAP25 Gene Polymorphisms Protect Against Parkinson's Disease and Modulate Disease Severity in Patients. Mol Neurobiol 2018; 56:4455-4463. [PMID: 30334187 DOI: 10.1007/s12035-018-1386-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/09/2018] [Indexed: 02/02/2023]
Abstract
Parkinson's disease (PD) is a α-synucleinopathy in which intracellular aggregates of α-synuclein (α-syn) result in neurodegeneration and in the impairment of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex-mediated release of neurotransmitters. SNAP25 is a SNARE complex component: its concentration is increased in the cerebrospinal fluid of PD patients and this is related to the severity of cognitive and motor symptoms. Five SNAP25 single-nucleotide polymorphisms (SNPs) that modulate gene expression and were described to play a role in neurologic conditions (rs363050, rs363039, rs363043, rs3746544, and rs1051312) were analyzed in a cohort of 412 sporadic Italian PD patients and 1103 healthy controls (HC) in order to identify possible correlation with the disease. The SNAP25 rs1051312 C allele and CC genotype confer protection against PD onset, in particular in males (p = 0.003, OR(95%CI) = 0.67(0.51-0.88)) (pc = 0.008, OR(95%CI) = 0.28(0.10-0.70)). Co-segregation analyses revealed that the rs1051312 effect was reinforced when present within the rs363043 C-rs3746544 T-rs1051312 C haplotype (p = 3.3 × 10-4, OR = 0.47, 95%CI = 0.31-0.72), once again in males. Finally, rs363039 influenced age at onset (p = 0.02) and MMSE (Mini-Mental State Examination) scores (p = 0.01). The SNAP25 SNPs analyzed herein modulate gene expression at different levels as they are involved in binding miRNA and transcription factors; this suggests a possible synergistic effect of SNAP25 SNPs in the pathogenesis of PD. A replication in a larger and independent sample will help to further explore this hypothesis.
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Affiliation(s)
| | | | | | - Giulio Riboldazzi
- Center for Parkinson's Disease and Movement Disorders, Ospedale di Circolo e Fondazione Macchi, Varese, Italy
| | - Roberta Zangaglia
- Parkinson's disease and Movement Disorders Unit, IRCCS National Neurological Institute C. Mondino, Pavia, Italy
| | - Andrea Sturchio
- Neurology Unit-Varese, Insubria University Varese, Varese, Italy
| | - Carlo Casali
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome, Rome, Italy
| | | | - Brigida Minafra
- Parkinson's disease and Movement Disorders Unit, IRCCS National Neurological Institute C. Mondino, Pavia, Italy
| | - Raffaello Nemni
- IRCCS Fondazione Don Carlo Gnocchi, Milano, Italy.,Department of Pathophisiology and Transplantation, University of Milan, Milan, Italy
| | - Mario Clerici
- IRCCS Fondazione Don Carlo Gnocchi, Milano, Italy.,Department of Pathophisiology and Transplantation, University of Milan, Milan, Italy
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42
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Bhasne K, Mukhopadhyay S. Formation of Heterotypic Amyloids: α-Synuclein in Co-Aggregation. Proteomics 2018; 18:e1800059. [PMID: 30216674 DOI: 10.1002/pmic.201800059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/28/2018] [Indexed: 12/13/2022]
Abstract
Protein misfolding resulting in the formation of ordered amyloid aggregates is associated with a number of devastating human diseases. Intrinsically disordered proteins (IDPs) do not autonomously fold up into a unique stable conformation and remain as an ensemble of rapidly fluctuating conformers. Many IDPs are prone to convert into the β-rich amyloid state. One such amyloidogenic IDP is α-synuclein that is involved in Parkinson's disease. Recent studies have indicated that other neuronal proteins, especially IDPs, can co-aggregate with α-synuclein in many pathological ailments. This article describes several such observations highlighting the role of heterotypic protein-protein interactions in the formation of hetero-amyloids. It is believed that the characterizations of molecular cross talks between amyloidogenic proteins as well as the mechanistic studies of heterotypic protein aggregation will allow us to decipher the role of the interacting proteins in amyloid proteomics.
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Affiliation(s)
- Karishma Bhasne
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab 140306, India.,Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab 140306, India
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab 140306, India.,Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab 140306, India
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43
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Zhang Z, Jiang X, Xu D, Zheng W, Liu M, Li C. Calcium accelerates SNARE-mediated lipid mixing through modulating α-synuclein membrane interaction. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1848-1853. [DOI: 10.1016/j.bbamem.2018.03.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/24/2018] [Accepted: 03/26/2018] [Indexed: 01/08/2023]
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44
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Abstract
α-Synuclein is an abundant neuronal protein that is highly enriched in presynaptic nerve terminals. Genetics and neuropathology studies link α-synuclein to Parkinson's disease (PD) and other neurodegenerative disorders. Accumulation of misfolded oligomers and larger aggregates of α-synuclein defines multiple neurodegenerative diseases called synucleinopathies, but the mechanisms by which α-synuclein acts in neurodegeneration are unknown. Moreover, the normal cellular function of α-synuclein remains debated. In this perspective, we review the structural characteristics of α-synuclein, its developmental expression pattern, its cellular and subcellular localization, and its function in neurons. We also discuss recent progress on secretion of α-synuclein, which may contribute to its interneuronal spread in a prion-like fashion, and describe the neurotoxic effects of α-synuclein that are thought to be responsible for its role in neurodegeneration.
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Affiliation(s)
- Jacqueline Burré
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10021
| | - Manu Sharma
- Appel Institute for Alzheimer's Disease Research, Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10021
| | - Thomas C Südhof
- Departments of Molecular and Cellular Physiology, Stanford University Medical School, Stanford, California 94305
- Howard Hughes Medical Institute, Stanford University Medical School, Stanford, California 94305
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45
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Abstract
Parkinson's disease (PD) is characterized by intracellular inclusions of aggregated and misfolded α-Synuclein (α-Syn), and the loss of dopaminergic (DA) neurons in the brain. The resulting motor abnormalities mark the progression of PD, while non-motor symptoms can already be identified during early, prodromal stages of disease. Recent studies provide evidence that during this early prodromal phase, synaptic and axonal abnormalities occur before the degenerative loss of neuronal cell bodies. These early phenotypes can be attributed to synaptic accumulation of toxic α-Syn. Under physiological conditions, α-Syn functions in its native conformation as a soluble monomer. However, PD patient brains are characterized by intracellular inclusions of insoluble fibrils. Yet, oligomers and protofibrils of α-Syn have been identified to be the most toxic species, with their accumulation at presynaptic terminals affecting several steps of neurotransmitter release. First, high levels of α-Syn alter the size of synaptic vesicle pools and impair their trafficking. Second, α-Syn overexpression can either misregulate or redistribute proteins of the presynaptic SNARE complex. This leads to deficient tethering, docking, priming and fusion of synaptic vesicles at the active zone (AZ). Third, α-Syn inclusions are found within the presynaptic AZ, accompanied by a decrease in AZ protein levels. Furthermore, α-Syn overexpression reduces the endocytic retrieval of synaptic vesicle membranes during vesicle recycling. These presynaptic alterations mediated by accumulation of α-Syn, together impair neurotransmitter exocytosis and neuronal communication. Although α-Syn is expressed throughout the brain and enriched at presynaptic terminals, DA neurons are the most vulnerable in PD, likely because α-Syn directly regulates dopamine levels. Indeed, evidence suggests that α-Syn is a negative modulator of dopamine by inhibiting enzymes responsible for its synthesis. In addition, α-Syn is able to interact with and reduce the activity of VMAT2 and DAT. The resulting dysregulation of dopamine levels directly contributes to the formation of toxic α-Syn oligomers. Together these data suggest a vicious cycle of accumulating α-Syn and deregulated dopamine that triggers synaptic dysfunction and impaired neuronal communication, ultimately causing synaptopathy and progressive neurodegeneration in Parkinson's disease.
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Affiliation(s)
- Jessika C Bridi
- King's College London, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
| | - Frank Hirth
- King's College London, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom
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46
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Bu B, Tong X, Li D, Hu Y, He W, Zhao C, Hu R, Li X, Shao Y, Liu C, Zhao Q, Ji B, Diao J. N-Terminal Acetylation Preserves α-Synuclein from Oligomerization by Blocking Intermolecular Hydrogen Bonds. ACS Chem Neurosci 2017; 8:2145-2151. [PMID: 28741930 DOI: 10.1021/acschemneuro.7b00250] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The abnormal aggregation of α-synuclein (α-Syn) is closely associated with Parkinson's disease. Different post-translational modifications of α-Syn have been identified and contribute distinctly in α-Syn aggregation and cytotoxicity. Recently, α-Syn was reported to be N-terminally acetylated in cells, yet the functional implication of this modification, especially in α-Syn oligomerization, remains unclear. By using a solid-state nanopore system, we found that N-terminal acetylation can significantly decrease α-Syn oligomerization. Replica-exchange molecular dynamics simulations further revealed that addition of an acetyl group at the N-terminus disrupts intermolecular hydrogen bonds, which slows down the initial α-Syn oligomerization. Our finding highlights the essential role of N-terminal acetylation of α-Syn in preserving its native conformation against pathological aggregation.
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Affiliation(s)
- Bing Bu
- Biomechanics
and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081, China
| | - Xin Tong
- State
Key Laboratory for Mesoscopic Physics and Electron Microscopy Laboratory,
School of Physics, Peking University, Beijing 100871, China
| | - Dechang Li
- Biomechanics
and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081, China
| | - Yachong Hu
- Department
of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States
- Key
Laboratory of Biomedical Information Engineering of the Ministry of
Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China
| | - Wangxiao He
- Key
Laboratory of Biomedical Information Engineering of the Ministry of
Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China
| | - Chunyu Zhao
- Interdisciplinary
Research Center on Biology and Chemistry, Shanghai Institute of Organic
Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Rui Hu
- State
Key Laboratory for Mesoscopic Physics and Electron Microscopy Laboratory,
School of Physics, Peking University, Beijing 100871, China
| | - Xiaoqing Li
- State
Key Laboratory for Mesoscopic Physics and Electron Microscopy Laboratory,
School of Physics, Peking University, Beijing 100871, China
| | - Yongping Shao
- Key
Laboratory of Biomedical Information Engineering of the Ministry of
Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China
| | - Cong Liu
- Interdisciplinary
Research Center on Biology and Chemistry, Shanghai Institute of Organic
Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Qing Zhao
- State
Key Laboratory for Mesoscopic Physics and Electron Microscopy Laboratory,
School of Physics, Peking University, Beijing 100871, China
| | - Baohua Ji
- Biomechanics
and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing 100081, China
| | - Jiajie Diao
- Department
of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States
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47
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Lautenschläger J, Kaminski CF, Kaminski Schierle GS. α-Synuclein – Regulator of Exocytosis, Endocytosis, or Both? Trends Cell Biol 2017; 27:468-479. [DOI: 10.1016/j.tcb.2017.02.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 02/01/2017] [Accepted: 02/02/2017] [Indexed: 10/20/2022]
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48
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α-Synuclein may cross-bridge v-SNARE and acidic phospholipids to facilitate SNARE-dependent vesicle docking. Biochem J 2017; 474:2039-2049. [PMID: 28495859 DOI: 10.1042/bcj20170200] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 12/11/2022]
Abstract
Misfolded α-synuclein (A-syn) is widely recognized as the primal cause of neurodegenerative diseases including Parkinson's disease and dementia with Lewy bodies. The normal cellular function of A-syn has, however, been elusive. There is evidence that A-syn plays multiple roles in the exocytotic pathway in the neuron, but the underlying molecular mechanisms are unclear. A-syn has been known to interact with negatively charged phospholipids and with vesicle SNARE protein VAMP2. Using single-vesicle docking/fusion assays, we find that A-syn promotes SNARE-dependent vesicles docking significantly at 2.5 µM. When phosphatidylserine (PS) is removed from t-SNARE-bearing vesicles, the docking enhancement by A-syn disappears and A-syn instead acts as an inhibitor for docking. In contrast, subtraction of PS from the v-SNARE-carrying vesicles enhances vesicle docking even further. Moreover, when we truncate the C-terminal 45 residues of A-syn that participates in interacting with VAMP2, the promotion of vesicle docking is abrogated. Thus, the results suggest that the A-syn's interaction with v-SNARE through its C-terminal tail and its concurrent interaction with PS in trans through its amphipathic N-terminal domain facilitate SNARE complex formation, whereby A-syn aids SNARE-dependent vesicle docking.
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49
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Eichmann C, Kumari P, Riek R. High-density lipoprotein-like particle formation of Synuclein variants. FEBS Lett 2017; 591:304-311. [PMID: 28027392 DOI: 10.1002/1873-3468.12543] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 11/11/2022]
Abstract
α-Synuclein (α-Syn) is an intrinsically disordered protein in solution whose fibrillar aggregates are the hallmark of Parkinson's disease (PD). Although the specific function of α-Syn is still unclear, its high structural plasticity is key for the interactions of α-Syn with biological membranes. Recently, it has been observed that α-Syn is able to form high-density lipoprotein-like (HDL-like) particles that are reminiscent of self-assembling phospholipid bilayer nanodiscs. Here, we extended our preparation method for the production of α-Syn lipoprotein particles to the β- and γ-Syn variants, and the PD-related familial α-Syn mutants. We show that all human Syns can form stable and homogeneous populations of HDL-like particles with distinct morphologies. Our results characterize the impact of the individual Syns on the formation capacity of these particles and indicate that Syn HDL-like particles are neither causing toxicity nor a toxicity-related loss of α-Syn in PD.
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Affiliation(s)
- Cédric Eichmann
- In-Cell NMR Laboratory, Department of NMR-supported Structural Biology, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Berlin, Germany
| | - Pratibha Kumari
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, Zürich, Switzerland
| | - Roland Riek
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, Zürich, Switzerland
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50
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Bellucci A, Mercuri NB, Venneri A, Faustini G, Longhena F, Pizzi M, Missale C, Spano P. Review: Parkinson's disease: from synaptic loss to connectome dysfunction. Neuropathol Appl Neurobiol 2016; 42:77-94. [PMID: 26613567 DOI: 10.1111/nan.12297] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 11/06/2015] [Accepted: 11/14/2015] [Indexed: 12/12/2022]
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder with prominent loss of nigro-striatal dopaminergic neurons. The resultant dopamine (DA) deficiency underlies the onset of typical motor symptoms (MS). Nonetheless, individuals affected by PD usually show a plethora of nonmotor symptoms (NMS), part of which may precede the onset of motor signs. Besides DA neuron degeneration, a key neuropathological alteration in the PD brain is Lewy pathology. This is characterized by abnormal intraneuronal (Lewy bodies) and intraneuritic (Lewy neurites) deposits of fibrillary aggregates mainly composed of α-synuclein. Lewy pathology has been hypothesized to progress in a stereotypical pattern over the course of PD and α-synuclein mutations and multiplications have been found to cause monogenic forms of the disease, thus raising the question as to whether this protein is pathogenic in this disorder. Findings showing that the majority of α-synuclein aggregates in PD are located at presynapses and this underlies the onset of synaptic and axonal degeneration, coupled to the fact that functional connectivity changes correlate with disease progression, strengthen this idea. Indeed, by altering the proper action of key molecules involved in the control of neurotransmitter release and re-cycling as well as synaptic and structural plasticity, α-synuclein deposition may crucially impair axonal trafficking, resulting in a series of noxious events, whose pressure may inevitably degenerate into neuronal damage and death. Here, we provide a timely overview of the molecular features of synaptic loss in PD and disclose their possible translation into clinical symptoms through functional disconnection.
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Affiliation(s)
- Arianna Bellucci
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | | | - Annalena Venneri
- IRCCS Fondazione Ospedale San Camillo (NHS-Italy), Venice Lido, Italy.,Department of Neuroscience, University of Sheffield, Sheffield, UK
| | - Gaia Faustini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Francesca Longhena
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Marina Pizzi
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.,IRCCS Fondazione Ospedale San Camillo (NHS-Italy), Venice Lido, Italy
| | - Cristina Missale
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - PierFranco Spano
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.,IRCCS Fondazione Ospedale San Camillo (NHS-Italy), Venice Lido, Italy
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