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Andica C, Kamagata K. Neural plasticity in Parkinson's disease: a neuroimaging perspective. Neural Regen Res 2024; 19:1203-1205. [PMID: 37905865 DOI: 10.4103/1673-5374.386404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 09/13/2023] [Indexed: 11/02/2023] Open
Affiliation(s)
- Christina Andica
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan (Andica C, Kamagata K)
- Faculty of Health Data Science, Juntendo University, Chiba, Japan (Andica C)
| | - Koji Kamagata
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan (Andica C, Kamagata K)
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Andica C, Kamagata K, Uchida W, Saito Y, Takabayashi K, Hagiwara A, Takeshige-Amano H, Hatano T, Hattori N, Aoki S. Fiber-Specific White Matter Alterations in Parkinson's Disease Patients with GBA Gene Mutations. Mov Disord 2023; 38:2019-2030. [PMID: 37608502 DOI: 10.1002/mds.29578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/21/2023] [Accepted: 07/31/2023] [Indexed: 08/24/2023] Open
Abstract
BACKGROUND Patients with Parkinson's disease (PD) carrying GBA gene mutations (GBA-PD) have a more aggressive disease course than those with idiopathic PD (iPD). OBJECTIVE The objective of this study was to investigate fiber-specific white matter (WM) differences in nonmedicated patients with early-stage GBA-PD and iPD using fixel-based analysis, a novel technique to assess tract-specific WM microstructural and macrostructural features comprehensively. METHODS Fixel-based metrics, including microstructural fiber density (FD), macrostructural fiber-bundle cross section (FC), and a combination of FD and FC (FDC), were compared among 30 healthy control subjects, 16 patients with GBA-PD, and 35 patients with iPD. Associations between FDC and clinical evaluations were also explored using multiple linear regression analyses. RESULTS Patients with GBA-PD showed significantly lower FD in the fornix and superior longitudinal fasciculus than healthy control subjects, and lower FC in the corticospinal tract (CST) and lower FDC in the CST, middle cerebellar peduncle, and striatal-thalamo-cortical pathways than patients with iPD. Contrarily, patients with iPD showed significantly higher FC and FDC in the CST and striatal-thalamo-cortical pathways than healthy control subjects. In addition, lower FDC in patients with GBA-PD was associated with reduced glucocerebrosidase enzyme activity, lower cerebrospinal fluid total α-synuclein levels, lower Montreal Cognitive Assessment scores, lower striatal binding ratio, and higher Unified Parkinson's Disease Rating Scale Part III scores. CONCLUSIONS We report reduced fiber-specific WM density and bundle cross-sectional size in patients with GBA-PD, suggesting neurodegeneration linked to glucocerebrosidase deficiency, α-synuclein accumulation, and poorer cognition and motor functions. Conversely, patients with iPD showed increased fiber bundle size, likely because of WM reorganization. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Grants
- Grant-in-Aid for Special Research in Subsidies for ordinary expenses of private schools from The Promotion and Mutual Aid Corporation for Private Schools of Japan
- JP21wm0425006 Japan Agency for Medical Research and Development
- 23H02865 Japan Society for the Promotion of Science
- 23K14927 Japan Society for the Promotion of Science
- PPMI - a public-private partnership - is funded by the Michael J. Fox Foundation for Parkinson's Research funding partners 4D Pharma, Abbvie, Acurex Therapeutics, Allergan, Amathus Therapeutics, ASAP, Avid Radiopharmaceuticals, Bial Biotech, Biogen, BioLegend, Bristol-Myers Squibb, Calico, Celgene, Dacapo Brain Science, Denali, The Edmond J. Safra Foundation, GE Healthcare, Genentech, GlaxoSmithKline, Golub Capital, Handl Therapeutics, Insitro, Janssen Neuroscience, Lilly, Lundbeck, Merck, M
- JP18dm0307004 The Brain/MINDS Beyond program of the Japan Agency for Medical Research and Development
- JP19dm0307101 The Brain/MINDS Beyond program of the Japan Agency for Medical Research and Development
- The Juntendo Research Branding Project
- The Project for Training Experts in Statistical Sciences
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Affiliation(s)
- Christina Andica
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Faculty of Health Data Science, Juntendo University, Chiba, Japan
| | - Koji Kamagata
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Wataru Uchida
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yuya Saito
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kaito Takabayashi
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Akifumi Hagiwara
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | | | - Taku Hatano
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
- Faculty of Health Data Science, Juntendo University, Chiba, Japan
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Horvath JD, Casas M, Kutchukian C, Sánchez SC, Pergande MR, Cologna SM, Simó S, Dixon RE, Dickson EJ. α-Synuclein-dependent increases in PIP5K1γ drive inositol signaling to promote neurotoxicity. Cell Rep 2023; 42:113244. [PMID: 37838947 PMCID: PMC11010634 DOI: 10.1016/j.celrep.2023.113244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 08/09/2023] [Accepted: 09/25/2023] [Indexed: 10/17/2023] Open
Abstract
Anomalous aggregation of α-synuclein (α-Syn) is a pathological hallmark of many degenerative synucleinopathies including Lewy body dementia (LBD) and Parkinson's disease (PD). Despite its strong link to disease, the precise molecular mechanisms that link α-Syn aggregation to neurodegeneration have yet to be elucidated. Here, we find that elevated α-Syn leads to an increase in the plasma membrane (PM) phosphoinositide PI(4,5)P2, which precipitates α-Syn aggregation and drives toxic increases in mitochondrial Ca2+ and reactive oxygen species leading to neuronal death. Upstream of this toxic signaling pathway is PIP5K1γ, whose abundance and localization is enhanced at the PM by α-Syn-dependent increases in ARF6. Selective inhibition of PIP5K1γ or knockout of ARF6 in neurons rescues α-Syn aggregation and cellular phenotypes of toxicity. Collectively, our data suggest that modulation of phosphoinositide metabolism may be a therapeutic target to slow neurodegeneration for PD and other related neurodegenerative disorders.
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Affiliation(s)
- Jonathan D Horvath
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | - Maria Casas
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | - Candice Kutchukian
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | - Sara Creus Sánchez
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | | | | | - Sergi Simó
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA 95616, USA
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA 95616, USA.
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Aggregation of alpha-synuclein in enteric neurons does not impact function in vitro. Sci Rep 2022; 12:22211. [PMID: 36564445 PMCID: PMC9789045 DOI: 10.1038/s41598-022-26543-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Recent evidence implicates a gut-first pathogenesis in the enteric nervous system (ENS) within a portion of PD patients, yet in vitro investigations have primarily focused on the central nervous system. Here, the preformed fibril (PFF) PD model is applied with co-administered groups of butyrate and lipopolysaccharide to model the effects of the local gut microbiome. Significant PFF uptake and retention occur in isolated rat enteric neurons compared to untreated controls resulting in increasing immunostained aggregate conformation-specific, alpha-synuclein (a-Syn) average intensity between 6 µg PFF and untreated controls. Cortical neurons significantly retain PFFs with an increase in aggregated a-Syn average intensity within all dosages. Differences in growth cone morphology but not dynamics in PFF-treated ENS cultures occur. Electrophysiological recordings via a microelectrode array (MEA) indicate no overall difference in spontaneous spike rate. However, only untreated controls respond to PD-relevant dopamine stimulus, while 1 µg PFF and control populations respond to stimulus with ENS-abundant acetylcholine. Finally, no differences in substance P levels-correlated with PD and neurodegeneration-are observed. Overall, these findings suggest the ENS retains PFF dosage absent acute loss in function, however, does experience changes in growth cone morphology and dopamine-stimulated activity.
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LRP1 is a neuronal receptor for α-synuclein uptake and spread. Mol Neurodegener 2022; 17:57. [PMID: 36056345 PMCID: PMC9438229 DOI: 10.1186/s13024-022-00560-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aggregation and spread of α-synuclein (α-Syn) protein and related neuronal toxicity are the key pathological features of Parkinson's disease (PD) and Lewy body dementia (LBD). Studies have shown that pathological species of α-Syn and tau can spread in a prion-like manner between neurons, although these two proteins have distinct pathological roles and contribute to different neurodegenerative diseases. It is reported that the low-density lipoprotein receptor-related protein 1 (LRP1) regulates the spread of tau proteins; however, the molecular regulatory mechanisms of α-Syn uptake and spread, and whether it is also regulated by LRP1, remain poorly understood. METHODS We established LRP1 knockout (LRP1-KO) human induced pluripotent stem cells (iPSCs) isogenic lines using a CRISPR/Cas9 strategy and generated iPSC-derived neurons (iPSNs) to test the role of LRP1 in α-Syn uptake. We treated the iPSNs with fluorescently labeled α-Syn protein and measured the internalization of α-Syn using flow cytometry. Three forms of α-Syn species were tested: monomers, oligomers, and pre-formed fibrils (PFFs). To examine whether the lysine residues of α-Syn are involved in LRP1-mediated uptake, we capped the amines of lysines on α-Syn with sulfo-NHS acetate and then measured the internalization. We also tested whether the N-terminus of α-Syn is critical for LRP1-mediated internalization. Lastly, we investigated the role of Lrp1 in regulating α-Syn spread with a neuronal Lrp1 conditional knockout (Lrp1-nKO) mouse model. We generated adeno-associated viruses (AAVs) that allowed for distinguishing the α-Syn expression versus spread and injected them into the hippocampus of six-month-old Lrp1-nKO mice and the littermate wild type (WT) controls. The spread of α-Syn was evaluated three months after the injection. RESULTS We found that the uptake of both monomeric and oligomeric α-Syn was significantly reduced in iPSNs with LRP1-KO compared with the WT controls. The uptake of α-Syn PFFs was also inhibited in LRP1-KO iPSNs, albeit to a much lesser extent compared to α-Syn monomers and oligomers. The blocking of lysine residues on α-Syn effectively decreased the uptake of α-Syn in iPSNs and the N-terminus of α-Syn was critical for LRP1-mediated α-Syn uptake. Finally, in the Lrp1-nKO mice, the spread of α-Syn was significantly reduced compared with the WT littermates. CONCLUSIONS We identified LRP1 as a key regulator of α-Syn neuronal uptake, as well as an important mediator of α-Syn spread in the brain. This study provides new knowledge on the physiological and pathological role of LRP1 in α-Syn trafficking and pathology, offering insight for the treatment of synucleinopathies.
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Zarkali A, McColgan P, Leyland LA, Lees AJ, Weil RS. Longitudinal thalamic white and grey matter changes associated with visual hallucinations in Parkinson's disease. J Neurol Neurosurg Psychiatry 2022; 93:169-179. [PMID: 34583941 PMCID: PMC8785065 DOI: 10.1136/jnnp-2021-326630] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 08/25/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Visual hallucinations are common in Parkinson's disease (PD) and associated with worse outcomes. Large-scale network imbalance is seen in PD-associated hallucinations, but mechanisms remain unclear. As the thalamus is critical in controlling cortical networks, structural thalamic changes could underlie network dysfunction in PD hallucinations. METHODS We used whole-brain fixel-based analysis and cortical thickness measures to examine longitudinal white and grey matter changes in 76 patients with PD (15 hallucinators, 61 non-hallucinators) and 26 controls at baseline, and after 18 months. We compared white matter and cortical thickness, adjusting for age, gender, time-between-scans and intracranial volume. To assess thalamic changes, we extracted volumes for 50 thalamic subnuclei (25 each hemisphere) and mean fibre cross-section (FC) for white matter tracts originating in each subnucleus and examined longitudinal change in PD-hallucinators versus non-hallucinators. RESULTS PD hallucinators showed white matter changes within the corpus callosum at baseline and extensive posterior tract involvement over time. Less extensive cortical thickness changes were only seen after follow-up. White matter connections from the right medial mediodorsal magnocellular thalamic nucleus showed reduced FC in PD hallucinators at baseline followed by volume reductions longitudinally. After follow-up, almost all thalamic subnuclei showed tract losses in PD hallucinators compared with non-hallucinators. INTERPRETATION PD hallucinators show white matter loss particularly in posterior connections and in thalamic nuclei, over time with relatively preserved cortical thickness. The right medial mediodorsal thalamic nucleus shows both connectivity and volume loss in PD hallucinations. Our findings provide mechanistic insights into the drivers of network imbalance in PD hallucinations and potential therapeutic targets.
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Affiliation(s)
| | - Peter McColgan
- Huntington's Disease Centre, UCL Institute of Neurology, London, UK
| | | | | | - Rimona Sharon Weil
- Dementia Research Centre, University College London, London, UK
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
- Movement Disorders Consortium, National Hospital for Neurology and Neurosurgery, London, UK
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Linetsky E, Abd Elhadi S, Bauer M, Gallant A, Namnah M, Weiss S, Segal D, Sharon R, Arkadir D. Safety and Tolerability, Dose-Escalating, Double-Blind Trial of Oral Mannitol in Parkinson's Disease. Front Neurol 2022; 12:716126. [PMID: 35046880 PMCID: PMC8761891 DOI: 10.3389/fneur.2021.716126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 12/10/2021] [Indexed: 11/13/2022] Open
Abstract
Mannitol, a natural alcoholic-sugar, was recently suggested as a potential disease-modifying agent in Parkinson's disease. In animal models of the disease, mannitol interferes with the formation of α-synuclein fibrils, inhibits the formation of α-synuclein oligomers and leads to phenotypic recovery of impaired motor functions. Parkinson's patients who consume mannitol report improvements of both motor and non-motor symptoms. Safety of long-term use of oral mannitol, tolerable dose and possible benefit, however, were never clinically studied. We studied the safety of oral mannitol in Parkinson's disease and assessed the maximal tolerable oral dose by conducting a phase IIa, randomized, double-blind, placebo-controlled, single-center, dose-escalating study (ClinicalTrials.gov Identifier: NCT03823638). The study lasted 36 weeks and included four dose escalations of oral mannitol or dextrose to a maximal dose of 18 g per day. The primary outcome was the safety of oral mannitol, as assessed by the number of adverse events and abnormal laboratory results. Clinical and biochemical efficacy measures were collected but were not statistically-powered. Fourteen patients receiving mannitol completed the trial (in addition to eight patients on placebo). Mannitol-related severe adverse events were not observed. Gastrointestinal symptoms limited dose escalation in 6/14 participants on mannitol. None of the clinical or biochemical efficacy secondary outcome measures significantly differed between groups. We concluded that long-term use of 18 g per day of oral mannitol is safe in Parkinson's disease patients but only two third of patients tolerate this maximal dose. These findings should be considered in the design of future efficacy trials.
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Affiliation(s)
- Eduard Linetsky
- Department of Neurology, Faculty of Medicine, Hadassah Medical Organization, Hebrew University, Jerusalem, Israel
| | - Suaad Abd Elhadi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Max Bauer
- Department of Neurology, Faculty of Medicine, Hadassah Medical Organization, Hebrew University, Jerusalem, Israel
| | - Akiva Gallant
- Department of Neurology, Faculty of Medicine, Hadassah Medical Organization, Hebrew University, Jerusalem, Israel
| | - Montaser Namnah
- Department of Neurology, Faculty of Medicine, Hadassah Medical Organization, Hebrew University, Jerusalem, Israel
| | | | - Daniel Segal
- Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv, Israel
| | - Ronit Sharon
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - David Arkadir
- Department of Neurology, Faculty of Medicine, Hadassah Medical Organization, Hebrew University, Jerusalem, Israel
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Loss of Corticostriatal Mu-Opioid Receptors in α-Synuclein Transgenic Mouse Brains. LIFE (BASEL, SWITZERLAND) 2022; 12:life12010063. [PMID: 35054456 PMCID: PMC8781165 DOI: 10.3390/life12010063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/28/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022]
Abstract
Ultrastructural, neurochemical, and molecular alterations within the striatum are associated with the onset and progression of Parkinson’s disease (PD). In PD, the dopamine-containing neurons in the substantia nigra pars compacta (SNc) degenerate and reduce dopamine-containing innervations to the striatum. The loss of striatal dopamine is associated with enhanced corticostriatal glutamatergic plasticity at the early stages of PD. However, with disease progression, the glutamatergic corticostriatal white matter tracts (WMTs) also degenerate. We analyzed the levels of Mu opioid receptors (MORs) in the corticostriatal WMTs, as a function of α-Synuclein (α-Syn) toxicity in transgenic mouse brains. Our data show an age-dependent loss of MOR expression levels in the striatum and specifically, within the caudal striatal WMTs in α-Syn tg mouse brains. The loss of MOR expression is associated with degeneration of the myelinated axons that are localized within the corticostriatal WMTs. In brains affected with late stages of PD, we detect evidence confirming the degeneration of myelinated axons within the corticostriatal WMTs. We conclude that loss of corticostriatal MOR expression is associated with degeneration of corticostriatal WMT in α-Syn tg mice, modeling PD.
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Fu Y, Zhou L, Li H, Hsiao JHT, Li B, Tanglay O, Auwyang AD, Wang E, Feng J, Kim WS, Liu J, Halliday GM. Adaptive structural changes in the motor cortex and white matter in Parkinson's disease. Acta Neuropathol 2022; 144:861-879. [PMID: 36053316 PMCID: PMC9547807 DOI: 10.1007/s00401-022-02488-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/19/2022] [Accepted: 08/27/2022] [Indexed: 01/26/2023]
Abstract
Parkinson's disease (PD) is a movement disorder characterized by the early loss of nigrostriatal dopaminergic pathways producing significant network changes impacting motor coordination. Recently three motor stages of PD have been proposed (a silent period when nigrostriatal loss begins, a prodromal motor period with subtle focal manifestations, and clinical PD) with evidence that motor cortex abnormalities occur to produce clinical PD[8]. We directly assess structural changes in the primary motor cortex and corticospinal tract using parallel analyses of longitudinal clinical and cross-sectional pathological cohorts thought to represent different stages of PD. 18F-FP-CIT positron emission tomography and subtle motor features identified patients with idiopathic rapid-eye-movement sleep behaviour disorder (n = 8) that developed prodromal motor signs of PD. Longitudinal diffusion tensor imaging before and after the development of prodromal motor PD showed higher fractional anisotropy in motor cortex and corticospinal tract compared to controls, indicating adaptive structural changes in motor networks in concert with nigrostriatal dopamine loss. Histological analyses of the white matter underlying the motor cortex showed progressive disorientation of axons with segmental replacement of neurofilaments with α-synuclein, enlargement of myelinating oligodendrocytes and increased density of their precursors. There was no loss of neurons in the motor cortex in early or late pathologically confirmed motor PD compared to controls, although there were early cortical increases in neuronal neurofilament light chain and myelin proteins in association with α-synuclein accumulation. Our results collectively provide evidence of a direct impact of PD on primary motor cortex and its output pathways that begins in the prodromal motor stage of PD with structural changes confirmed in early PD. These adaptive structural changes become considerable as the disease advances potentially contributing to motor PD.
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Affiliation(s)
- YuHong Fu
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Liche Zhou
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Hongyun Li
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Jen-Hsiang T. Hsiao
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Binyin Li
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Onur Tanglay
- Neuroscience Research Australia & Faculty of Medicine School of Medical Sciences, University of New South Wales, Sydney, NSW 2052 Australia
| | - Andrew D. Auwyang
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Elinor Wang
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Jieyao Feng
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia
| | - Woojin S. Kim
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia ,Neuroscience Research Australia & Faculty of Medicine School of Medical Sciences, University of New South Wales, Sydney, NSW 2052 Australia
| | - Jun Liu
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Glenda M. Halliday
- Brain and Mind Centre & Faculty of Medicine and Health School of Medical Sciences, The University of Sydney, Sydney, NSW 2050 Australia ,Neuroscience Research Australia & Faculty of Medicine School of Medical Sciences, University of New South Wales, Sydney, NSW 2052 Australia
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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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Van Den Berge N, Ferreira N, Mikkelsen TW, Alstrup AKO, Tamgüney G, Karlsson P, Terkelsen AJ, Nyengaard JR, Jensen PH, Borghammer P. Ageing promotes pathological alpha-synuclein propagation and autonomic dysfunction in wild-type rats. Brain 2021; 144:1853-1868. [PMID: 33880502 PMCID: PMC8320301 DOI: 10.1093/brain/awab061] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 11/13/2020] [Accepted: 12/10/2020] [Indexed: 12/16/2022] Open
Abstract
Neuronal aggregates of misfolded alpha-synuclein protein are found in the brain and periphery of patients with Parkinson's disease. Braak and colleagues have hypothesized that the initial formation of misfolded alpha-synuclein may start in the gut, and then spread to the brain via peripheral autonomic nerves hereby affecting several organs, including the heart and intestine. Age is considered the greatest risk factor for Parkinson's disease, but the effect of age on the formation of pathology and its propagation has not been studied in detail. We aimed to investigate whether propagation of alpha-synuclein pathology from the gut to the brain is more efficient in old versus young wild-type rats, upon gastrointestinal injection of aggregated alpha-synuclein. Our results demonstrate a robust age-dependent gut-to-brain and brain-to-gut spread of alpha-synuclein pathology along the sympathetic and parasympathetic nerves, resulting in age-dependent dysfunction of the heart and stomach, as observed in patients with Parkinson's disease. Moreover, alpha-synuclein pathology is more densely packed and resistant to enzymatic digestion in old rats, indicating an age-dependent maturation of alpha-synuclein aggregates. Our study is the first to provide a detailed investigation of alpha-synuclein pathology in several organs within one animal model, including the brain, skin, heart, intestine, spinal cord and autonomic ganglia. Taken together, our findings suggest that age is a crucial factor for alpha-synuclein aggregation and complete propagation to heart, stomach and skin, similar to patients. Given that age is the greatest risk factor for human Parkinson's disease, it seems likely that older experimental animals will yield the most relevant and reliable findings. These results have important implications for future research to optimize diagnostics and therapeutics in Parkinson's disease and other age-associated synucleinopathies. Increased emphasis should be placed on using aged animals in preclinical studies and to elucidate the nature of age-dependent interactions.
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Affiliation(s)
- Nathalie Van Den Berge
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Nelson Ferreira
- DANDRITE-Danish Research Institute of Translational Neuroscience and Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Aage Kristian Olsen Alstrup
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
| | - Gültekin Tamgüney
- Institute of Physical Biology, Heinrich-Heine-University, Düsseldorf, Germany
- Institute of Biological Information Processing, Structural Biochemistry (IBI-7), Forschungszentrum Jülich, Jülich, Germany
| | - Páll Karlsson
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Medicine, The Danish Pain Research Center, Aarhus University, Aarhus, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Astrid Juhl Terkelsen
- Department of Clinical Medicine, The Danish Pain Research Center, Aarhus University, Aarhus, Denmark
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Jens Randel Nyengaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Center for Stochastic Geometry and Advanced Bioimaging, Aarhus University, Aarhus, Denmark
| | - Poul Henning Jensen
- DANDRITE-Danish Research Institute of Translational Neuroscience and Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Per Borghammer
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Aarhus, Denmark
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12
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Andica C, Kamagata K, Saito Y, Uchida W, Fujita S, Hagiwara A, Akashi T, Wada A, Ogawa T, Hatano T, Hattori N, Aoki S. Fiber-specific white matter alterations in early-stage tremor-dominant Parkinson's disease. NPJ PARKINSONS DISEASE 2021; 7:51. [PMID: 34172728 PMCID: PMC8233424 DOI: 10.1038/s41531-021-00197-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 06/04/2021] [Indexed: 12/14/2022]
Abstract
Using a fixel-based analysis (FBA), we assessed the fiber-specific white matter (WM) alterations in nonmedicated patients with early-stage Parkinson's disease (PD) with tremor-dominant (TD; n = 53; mean age, 61.7 ± 8.7 years) and postural instability and gait disorder (PIGD; n = 27; mean age, 57.8 ± 8.1 years) motor subtypes and age- and sex-matched healthy controls (HC; n = 43; mean age, 61.6 ± 9.2 years) from Parkinson's Progression Markers Initiative dataset. FBA revealed significantly increased macrostructural fiber cross section and a combination of fiber density and cross section metrics within the corticospinal tract in patients with TD-PD compared with HC. Nonetheless, no significant changes in FBA-derived metrics were found in patients with PIGD-PD compared with HC or patients with TD-PD. Our results may provide evidence of WM neural compensation mechanisms in patients with TD-PD marked by increases in fiber bundle size and the ability to relay information between brain regions.
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Affiliation(s)
- Christina Andica
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
| | - Koji Kamagata
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
| | - Yuya Saito
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Wataru Uchida
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Shohei Fujita
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Akifumi Hagiwara
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Toshiaki Akashi
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Akihiko Wada
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Takashi Ogawa
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Taku Hatano
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shigeki Aoki
- Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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13
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Motyl JA, Strosznajder JB, Wencel A, Strosznajder RP. Recent Insights into the Interplay of Alpha-Synuclein and Sphingolipid Signaling in Parkinson's Disease. Int J Mol Sci 2021; 22:ijms22126277. [PMID: 34207975 PMCID: PMC8230587 DOI: 10.3390/ijms22126277] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 01/22/2023] Open
Abstract
Molecular studies have provided increasing evidence that Parkinson’s disease (PD) is a protein conformational disease, where the spread of alpha-synuclein (ASN) pathology along the neuraxis correlates with clinical disease outcome. Pathogenic forms of ASN evoke oxidative stress (OS), neuroinflammation, and protein alterations in neighboring cells, thereby intensifying ASN toxicity, neurodegeneration, and neuronal death. A number of evidence suggest that homeostasis between bioactive sphingolipids with opposing function—e.g., sphingosine-1-phosphate (S1P) and ceramide—is essential in pro-survival signaling and cell defense against OS. In contrast, imbalance of the “sphingolipid biostat” favoring pro-oxidative/pro-apoptotic ceramide-mediated changes have been indicated in PD and other neurodegenerative disorders. Therefore, we focused on the role of sphingolipid alterations in ASN burden, as well as in a vast range of its neurotoxic effects. Sphingolipid homeostasis is principally directed by sphingosine kinases (SphKs), which synthesize S1P—a potent lipid mediator regulating cell fate and inflammatory response—making SphK/S1P signaling an essential pharmacological target. A growing number of studies have shown that S1P receptor modulators, and agonists are promising protectants in several neurological diseases. This review demonstrates the relationship between ASN toxicity and alteration of SphK-dependent S1P signaling in OS, neuroinflammation, and neuronal death. Moreover, we discuss the S1P receptor-mediated pathways as a novel promising therapeutic approach in PD.
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Affiliation(s)
- Joanna A. Motyl
- Department of Hybrid Microbiosystems Engineering, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4 St., 02-109 Warsaw, Poland; (J.A.M.); (A.W.)
| | - Joanna B. Strosznajder
- Department of Cellular Signalling, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland;
| | - Agnieszka Wencel
- Department of Hybrid Microbiosystems Engineering, Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Ks. Trojdena 4 St., 02-109 Warsaw, Poland; (J.A.M.); (A.W.)
| | - Robert P. Strosznajder
- Laboratory of Preclinical Research and Environmental Agents, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawinskiego St., 02-106 Warsaw, Poland
- Correspondence:
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14
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Yang Y, Ye C, Sun J, Liang L, Lv H, Gao L, Fang J, Ma T, Wu T. Alteration of brain structural connectivity in progression of Parkinson's disease: A connectome-wide network analysis. Neuroimage Clin 2021; 31:102715. [PMID: 34130192 PMCID: PMC8209844 DOI: 10.1016/j.nicl.2021.102715] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/08/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
Pinpointing the brain dysconnectivity in idiopathic rapid eye movement sleep behaviour disorder (iRBD) can facilitate preventing the conversion of Parkinson's disease (PD) from prodromal phase. Recent neuroimage investigations reported disruptive brain white matter connectivity in both iRBD and PD, respectively. However, the intrinsic process of the human brain structural network evolving from iRBD to PD still remains largely unknown. To address this issue, 151 participants including iRBD, PD and age-matched normal controls were recruited to receive diffusion MRI scans and neuropsychological examinations. The connectome-wide association analysis was performed to detect reorganization of brain structural network along with PD progression. Eight brain seed regions in both cortical and subcortical areas demonstrated significant structural pattern changes along with the progression of PD. Applying machine learning on the key connectivity related to these seed regions demonstrated better classification accuracy compared to conventional network-based statistic. Our study shows that connectome-wide association analysis reveals the underlying structural connectivity patterns related to the progression of PD, and provide a promising distinct capability to predict prodromal PD patients.
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Affiliation(s)
- Yanwu Yang
- Department of Electronic and Information Engineering, Harbin Institute of Technology at Shenzhen, Shenzhen, China
| | | | - Junyan Sun
- Department of Neurobiology, Neurology and Geriatrics, Xuanwu Hospital, Capital Medical University, National Clinical Research Center for Geriatric Disease, Beijing, China
| | - Li Liang
- Department of Electronic and Information Engineering, Harbin Institute of Technology at Shenzhen, Shenzhen, China
| | - Haiyan Lv
- MindsGo Shenzhen Life Science Co. Ltd, Shenzhen, China
| | - Linlin Gao
- Department of Neurobiology, Neurology and Geriatrics, Xuanwu Hospital, Capital Medical University, National Clinical Research Center for Geriatric Disease, Beijing, China
| | - Jiliang Fang
- Department of Radiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Ting Ma
- Department of Electronic and Information Engineering, Harbin Institute of Technology at Shenzhen, Shenzhen, China; Peng Cheng Laboratory, Shenzhen, China; Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China; National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing, China.
| | - Tao Wu
- Department of Neurobiology, Neurology and Geriatrics, Xuanwu Hospital, Capital Medical University, National Clinical Research Center for Geriatric Disease, Beijing, China.
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15
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Jacob RS, Eichmann C, Dema A, Mercadante D, Selenko P. α-Synuclein plasma membrane localization correlates with cellular phosphatidylinositol polyphosphate levels. eLife 2021; 10:61951. [PMID: 33587036 PMCID: PMC7929559 DOI: 10.7554/elife.61951] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 02/12/2021] [Indexed: 12/11/2022] Open
Abstract
The Parkinson's disease protein α-synuclein (αSyn) promotes membrane fusion and fission by interacting with various negatively charged phospholipids. Despite postulated roles in endocytosis and exocytosis, plasma membrane (PM) interactions of αSyn are poorly understood. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), two highly acidic components of inner PM leaflets, mediate PM localization of endogenous pools of αSyn in A2780, HeLa, SK-MEL-2, and differentiated and undifferentiated neuronal SH-SY5Y cells. We demonstrate that αSyn binds to reconstituted PIP2 membranes in a helical conformation in vitro and that PIP2 synthesizing kinases and hydrolyzing phosphatases reversibly redistribute αSyn in cells. We further delineate that αSyn-PM targeting follows phosphoinositide-3 kinase (PI3K)-dependent changes of cellular PIP2 and PIP3 levels, which collectively suggests that phosphatidylinositol polyphosphates contribute to αSyn's function(s) at the plasma membrane.
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Affiliation(s)
- Reeba Susan Jacob
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Cédric Eichmann
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Alessandro Dema
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Davide Mercadante
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Philipp Selenko
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
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16
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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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17
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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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