scholarly journals Differential regulation of wild-type and mutant alpha-synuclein binding to synaptic membranes by cytosolic factors

2008 ◽  
Vol 9 (1) ◽  
Author(s):  
Sabine Wislet-Gendebien ◽  
Naomi P Visanji ◽  
Shawn N Whitehead ◽  
Diana Marsilio ◽  
Weimin Hou ◽  
...  
Keyword(s):  
Cellular Localization ◽  
Membrane Binding ◽  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Major Constituent ◽  
Synaptic Membranes ◽  
Synaptic Membrane ◽  
Missense Mutations ◽  
Cytosolic Factors ◽  
Brain Cytosol

Abstract Background Alpha-Synuclein (α-syn), a 140 amino acid protein associated with presynaptic membranes in brain, is a major constituent of Lewy bodies in Parkinson's disease (PD). Three missense mutations (A30P, A53T and E46K) in the α-syn gene are associated with rare autosomal dominant forms of familial PD. However, the regulation of α-syn's cellular localization in neurons and the effects of the PD-linked mutations are poorly understood. Results In the present study, we analysed the ability of cytosolic factors to regulate α-syn binding to synaptic membranes. We show that co-incubation with brain cytosol significantly increases the membrane binding of normal and PD-linked mutant α-syn. To characterize cytosolic factor(s) that modulate α-syn binding properties, we investigated the ability of proteins, lipids, ATP and calcium to modulate α-syn membrane interactions. We report that lipids and ATP are two of the principal cytosolic components that modulate Wt and A53T α-syn binding to the synaptic membrane. We further show that 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (C16:0 PAF) is one of the principal lipids found in complex with cytosolic proteins and is required to enhance α-syn interaction with synaptic membrane. In addition, the impaired membrane binding observed for A30P α-syn was significantly mitigated by the presence of protease-sensitive factors in brain cytosol. Conclusion These findings suggest that endogenous brain cytosolic factors regulate Wt and mutant α-syn membrane binding, and could represent potential targets to influence α-syn solubility in brain.

scholarly journals Possible Role of Amyloidogenic Evolvability in Dementia with Lewy Bodies: Insights from Transgenic Mice Expressing P123H β-Synuclein

2020 ◽  
Vol 21 (8) ◽  
pp. 2849
Author(s):  
Masayo Fujita ◽  
Gilbert Ho ◽  
Yoshiki Takamatsu ◽  
Ryoko Wada ◽  
Kazutaka Ikeda ◽  
...  
Keyword(s):  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Gene Mutations ◽  
Major Constituent ◽  
Motor Deficits ◽  
Missense Mutations ◽  
Axonal Swelling ◽  
Disease Modifying Therapy ◽  
Progressive Neurodegeneration ◽  
Disease Modifying

Dementia with Lewy bodies (DLB) is the second most prevalent neurodegenerative dementia after Alzheimer’s disease, and is pathologically characterized by formation of intracellular inclusions called Lewy bodies, the major constituent of which is aggregated α-synuclein (αS). Currently, neither a mechanistic etiology nor an effective disease-modifying therapy for DLB has been established. Although two missense mutations of β-synuclein (βS), V70M and P123H, were identified in sporadic and familial DLB, respectively, the precise mechanisms through which βS mutations promote DLB pathogenesis remain elusive. To further clarify such mechanisms, we investigated transgenic (Tg) mice expressing P123H βS, which develop progressive neurodegeneration in the form of axonal swelling and non-motor behaviors, such as memory dysfunction and depression, which are more prominent than motor deficits. Furthermore, cross-breeding of P123H βS Tg mice with αS Tg mice worsened the neurodegenerative phenotype presumably through the pathological cross-seeding of P123H βS with αS. Collectively, we predict that βS misfolding due to gene mutations might be pathogenic. In this paper, we will discuss the possible involvement of amyloidogenic evolvability in the pathogenesis of DLB based on our previous papers regarding the P123H βS Tg mice. Given that stimulation of αS evolvability by P123H βS may underlie neuropathology in our mouse model, more radical disease-modifying therapy might be derived from the evolvability mechanism. Additionally, provided that altered βS were involved in the pathogenesis of sporadic DLB, the P123H βS Tg mice could be used for investigating the mechanism and therapy of DLB.

scholarly journals Retraction Note to: Differential regulation of wild-type and mutant alpha-synuclein binding to synaptic membranes by cytosolic factors

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sabine Wislet-Gendebien ◽  
Naomi P. Visanji ◽  
Shawn N. Whitehead ◽  
Diana Marsilio ◽  
Weimin Hou ◽  
...  
Keyword(s):  
Alpha Synuclein ◽  
Differential Regulation ◽  
Synaptic Membranes ◽  
Wild Type ◽  
Retraction Notice ◽  
Cytosolic Factors

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s12868-021-00644-1

scholarly journals Effect of Ser-129 Phosphorylation on Interaction of α-Synuclein with Synaptic and Cellular Membranes

2011 ◽  
Vol 286 (41) ◽  
pp. 35863-35873 ◽  
Author(s):  
Naomi P. Visanji ◽  
Sabine Wislet-Gendebien ◽  
Loren W. Oschipok ◽  
Gang Zhang ◽  
Isabelle Aubert ◽  
...  
Keyword(s):  
Proteasome Inhibitor ◽  
Membrane Binding ◽  
Lewy Bodies ◽  
Neural Precursor Cells ◽  
Synaptic Membranes ◽  
Membrane Association ◽  
Synaptosomal Membranes ◽  
Multiple Strategies ◽  
Membrane Bound ◽  
Deficient Mice

In the healthy brain, less than 5% of α-synuclein (α-syn) is phosphorylated at serine 129 (Ser(P)-129). However, within Parkinson disease (PD) Lewy bodies, 89% of α-syn is Ser(P)-129. The effects of Ser(P)-129 modification on α-syn distribution and solubility are poorly understood. As α-syn normally exists in both membrane-bound and cytosolic compartments, we examined the binding and dissociation of Ser(P)-129 α-syn and analyzed the effects of manipulating Ser(P)-129 levels on α-syn membrane interactions using synaptosomal membranes and neural precursor cells from α-syn-deficient mice or transgenic mice expressing human α-syn. We first evaluated the recovery of the Ser(P)-129 epitope following either α-syn membrane binding or dissociation. We demonstrate a rapid turnover of Ser(P)-129 during both binding to and dissociation from synaptic membranes. Although the membrane binding of WT α-syn was insensitive to modulation of Ser(P)-129 levels by multiple strategies (the use of phosphomimic S129D and nonphosphorylated S129A α-syn mutants; by enzymatic dephosphorylation of Ser(P)-129 or proteasome inhibitor-induced elevation in Ser(P)-129; or by inhibition or stable overexpression of PLK2), PD mutant Ser(P)-129 α-syn showed a preferential membrane association compared with WT Ser(P)-129 α-syn. Collectively, these data suggest that phosphorylation at Ser-129 is dynamic and that the subcellular distribution of α-syn bearing PD-linked mutations, A30P or A53T, is influenced by the phosphorylation state of Ser-129.

scholarly journals Brazilin Removes Toxic alpha-Synuclein and Seeding Competent Assemblies from Parkinson Brain by Altering Conformational Equilibrium

2020 ◽  
Author(s):  
George R. Nahass ◽  
Yuanzi Sun ◽  
Yong Xu ◽  
Mark Batchelor ◽  
Madeleine Reilly ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Amyloid Fibrils ◽  
Disease Patient ◽  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Major Constituent ◽  
List Type ◽  
Natural Polyphenol ◽  
Β Sheet

ABSTRACTAlpha-synuclein (α-syn) fibrils, a major constituent of the neurotoxic Lewy Bodies in Parkinson’s disease, form via nucleation dependent polymerization and can replicate by a seeding mechanism. Brazilin, a small molecule derived from red cedarwood trees in Brazil, has been shown to inhibit the fibrillogenesis of amyloid-beta (Aβ) and α-syn, prompting our inquiry in its mechanism of action. Here we test the effects of Brazilin on both seeded and unseeded α-syn fibril formation and show that the natural polyphenol inhibits fibrillogenesis of α-syn by a unique mechanism that is distinct from other polyphenols and is also distinct from its effect on Aβ. Brazilin preserves the natively unfolded state of α-syn by stabilizing the compact conformation of the α-syn monomer over the aggregation-competent extended conformation. Molecular docking of Brazilin shows the molecule to interact both with unfolded α-syn monomers and with the cross-β sheet structure of α-syn fibrils. Brazilin eliminates seeding competence of α-syn assemblies from Parkinson’s disease patient brain tissue, and treatment of pre-formed fibril assemblies with Brazilin significantly reduces their toxicity in primary neurons. Our findings suggest that Brazilin has substantial potential as a neuroprotective and therapeutic agent for Parkinson’s Disease.Highlights- The natural polyphenol Brazilin binds to monomeric, oligomeric and fibrillar α-syn- Brazilin shifts the equilibrium away from aggregation-competent monomer conformations- Brazilin inactivates seeding-competent α-syn isolated from Parkinson patients’ brains- Brazilin detoxifies α-syn aggregation intermediates and stabilizes mature amyloid fibrilsGraphical Abstract

scholarly journals The Catecholaldehyde Hypothesis for the Pathogenesis of Catecholaminergic Neurodegeneration: What We Know and What We Do Not Know

2021 ◽  
Vol 22 (11) ◽  
pp. 5999
Author(s):  
David S. Goldstein
Keyword(s):  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Future Research ◽  
Catecholamine Metabolism ◽  
Secondary Effects ◽  
Drug Induced ◽  
Neuronal Homeostasis ◽  
Mitochondrial Functions ◽  
Environmental Agents ◽  
Spontaneous Oxidation

3,4-Dihydroxyphenylacetaldehyde (DOPAL) is the focus of the catecholaldehyde hypothesis for the pathogenesis of Parkinson’s disease and other Lewy body diseases. The catecholaldehyde is produced via oxidative deamination catalyzed by monoamine oxidase (MAO) acting on cytoplasmic dopamine. DOPAL is autotoxic, in that it can harm the same cells in which it is produced. Normally, DOPAL is detoxified by aldehyde dehydrogenase (ALDH)-mediated conversion to 3,4-dihydroxyphenylacetic acid (DOPAC), which rapidly exits the neurons. Genetic, environmental, or drug-induced manipulations of ALDH that build up DOPAL promote catecholaminergic neurodegeneration. A concept derived from the catecholaldehyde hypothesis imputes deleterious interactions between DOPAL and the protein alpha-synuclein (αS), a major component of Lewy bodies. DOPAL potently oligomerizes αS, and αS oligomers impede vesicular and mitochondrial functions, shifting the fate of cytoplasmic dopamine toward the MAO-catalyzed formation of DOPAL—destabilizing vicious cycles. Direct and indirect effects of DOPAL and of DOPAL-induced misfolded proteins could “freeze” intraneuronal reactions, plasticity of which is required for neuronal homeostasis. The extent to which DOPAL toxicity is mediated by interactions with αS, and vice versa, is poorly understood. Because of numerous secondary effects such as augmented spontaneous oxidation of dopamine by MAO inhibition, there has been insufficient testing of the catecholaldehyde hypothesis in animal models. The clinical pathophysiological significance of genetics, emotional stress, environmental agents, and interactions with numerous proteins relevant to the catecholaldehyde hypothesis are matters for future research. The imposing complexity of intraneuronal catecholamine metabolism seems to require a computational modeling approach to elucidate clinical pathogenetic mechanisms and devise pathophysiology-based, individualized treatments.

scholarly journals Neurons and Glia Interplay in α-Synucleinopathies

2021 ◽  
Vol 22 (9) ◽  
pp. 4994
Author(s):  
Panagiota Mavroeidi ◽  
Maria Xilouri
Keyword(s):  
Glial Cells ◽  
Current Knowledge ◽  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Lewy Neurites ◽  
Cytoplasmic Inclusions ◽  
Glial Cytoplasmic Inclusions ◽  
Glial Function ◽  
Presynaptic Protein

Accumulation of the neuronal presynaptic protein alpha-synuclein within proteinaceous inclusions represents the key histophathological hallmark of a spectrum of neurodegenerative disorders, referred to by the umbrella term a-synucleinopathies. Even though alpha-synuclein is expressed predominantly in neurons, pathological aggregates of the protein are also found in the glial cells of the brain. In Parkinson’s disease and dementia with Lewy bodies, alpha-synuclein accumulates mainly in neurons forming the Lewy bodies and Lewy neurites, whereas in multiple system atrophy, the protein aggregates mostly in the glial cytoplasmic inclusions within oligodendrocytes. In addition, astrogliosis and microgliosis are found in the synucleinopathy brains, whereas both astrocytes and microglia internalize alpha-synuclein and contribute to the spread of pathology. The mechanisms underlying the pathological accumulation of alpha-synuclein in glial cells that under physiological conditions express low to non-detectable levels of the protein are an area of intense research. Undoubtedly, the presence of aggregated alpha-synuclein can disrupt glial function in general and can contribute to neurodegeneration through numerous pathways. Herein, we summarize the current knowledge on the role of alpha-synuclein in both neurons and glia, highlighting the contribution of the neuron-glia connectome in the disease initiation and progression, which may represent potential therapeutic target for a-synucleinopathies.

scholarly journals Multiple system atrophy-associated oligodendroglial protein p25α stimulates formation of novel α-synuclein strain with enhanced neurodegenerative potential

2021 ◽  
Author(s):  
Nelson Ferreira ◽  
Hjalte Gram ◽  
Zachary A. Sorrentino ◽  
Emil Gregersen ◽  
Sissel Ida Schmidt ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Protein Misfolding ◽  
Resonance Energy Transfer ◽  
Lewy Bodies ◽  
Resonance Energy ◽  
Alpha Synuclein ◽  
Striatal Neurons ◽  
End Stage ◽  
Intracellular Aggregates

AbstractPathology consisting of intracellular aggregates of alpha-Synuclein (α-Syn) spread through the nervous system in a variety of neurodegenerative disorders including Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy. The discovery of structurally distinct α-Syn polymorphs, so-called strains, supports a hypothesis where strain-specific structures are templated into aggregates formed by native α-Syn. These distinct strains are hypothesised to dictate the spreading of pathology in the tissue and the cellular impact of the aggregates, thereby contributing to the variety of clinical phenotypes. Here, we present evidence of a novel α-Syn strain induced by the multiple system atrophy-associated oligodendroglial protein p25α. Using an array of biophysical, biochemical, cellular, and in vivo analyses, we demonstrate that compared to α-Syn alone, a substoichiometric concentration of p25α redirects α-Syn aggregation into a unique α-Syn/p25α strain with a different structure and enhanced in vivo prodegenerative properties. The α-Syn/p25α strain induced larger inclusions in human dopaminergic neurons. In vivo, intramuscular injection of preformed fibrils (PFF) of the α-Syn/p25α strain compared to α-Syn PFF resulted in a shortened life span and a distinct anatomical distribution of inclusion pathology in the brain of a human A53T transgenic (line M83) mouse. Investigation of α-Syn aggregates in brain stem extracts of end-stage mice demonstrated that the more aggressive phenotype of the α-Syn/p25α strain was associated with an increased load of α-Syn aggregates based on a Förster resonance energy transfer immunoassay and a reduced α-Syn aggregate seeding activity based on a protein misfolding cyclic amplification assay. When injected unilaterally into the striata of wild-type mice, the α-Syn/p25α strain resulted in a more-pronounced motoric phenotype than α-Syn PFF and exhibited a “tropism” for nigro-striatal neurons compared to α-Syn PFF. Overall, our data support a hypothesis whereby oligodendroglial p25α is responsible for generating a highly prodegenerative α-Syn strain in multiple system atrophy.

ALPHA SYNUCLEIN IMMUNOREACTIVITY IN DEMENTIA WITH LEWY BODIES

1999 ◽  
Vol 58 (5) ◽  
pp. 553
Author(s):  
E Gómez-Tortosa ◽  
K L Newell ◽  
M C Irizarry ◽  
M Albert ◽  
J H Growdon ◽  
...  
Keyword(s):  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Alpha Synuclein

[P1-243]: ALPHA-SYNUCLEIN SPECIES AS POTENTIAL CSF BIOMARKERS FOR DEMENTIA WITH LEWY BODIES

2017 ◽  
Vol 13 (7S_Part_7) ◽  
pp. P338-P338 ◽  
Author(s):  
Inger van Steenoven ◽  
Nour K. Majbour ◽  
Nishant N. Vaikath ◽  
Henk W. Berendse ◽  
Wiesje M. van der Flier ◽  
...  
Keyword(s):  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Csf Biomarkers

Are lysosomes potential therapeutic targets for Parkinson’s disease?

2021 ◽  
Vol 20 ◽  
Author(s):  
A. Petese ◽  
V. Cesaroni ◽  
S. Cerri ◽  
F. Blandini
Keyword(s):  
Neurodegenerative Disorder ◽  
Association Studies ◽  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Genome Wide Association Studies ◽  
Lysosomal Dysfunction ◽  
Genome Wide ◽  
Nigrostriatal Neurons ◽  
Disease Modifying Treatment ◽  
Alpha Synuclein Aggregation

Background: Parkinson´s disease (PD) is the second most common neurodegenerative disorder, affecting 2-3% of the population over 65 years old. In addition to progressive degeneration of nigrostriatal neurons, the histopathological feature of PD is the accumulation of misfolded α-synuclein protein in abnormal cytoplasmatic inclusions, known as Lewy bodies (LBs). Recently, genome-wide association studies (GWAS) have indicated a clear association of variants within several lysosomal genes with risk for PD. Newly evolving data have been shedding light on the relationship between lysosomal dysfunction and alpha-synuclein aggregation. Defects in lysosomal enzymes could lead to the insufficient clearance of neurotoxic protein materials, possibly leading to selective degeneration of dopaminergic neurons. Specific modulation of lysosomal pathways and their components could be considered a novel opportunity for therapeutic intervention for PD. Aim: The purpose of this review is to illustrate lysosomal biology and describe the role of lysosomal dysfunction in PD pathogenesis. Finally, the most promising novel therapeutic approaches designed to modulate lysosomal activity, as a potential disease-modifying treatment for PD will be highlighted.

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