The Compound ATH434 Prevents Alpha-Synuclein Toxicity in a Murine Model of Multiple System Atrophy

2021 ◽  
pp. 1-11
Author(s):  
David I. Finkelstein ◽  
Jay J. Shukla ◽  
Robert A. Cherny ◽  
Jessica L. Billings ◽  
Eiman Saleh ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Pharmacokinetic Profile ◽  
Alpha Synuclein ◽  
Redox Activity ◽  
Substantia Nigra Pars Compacta ◽  
Drug Candidate ◽  
Older Volunteers ◽  
Control Food ◽  
Alpha Synuclein Aggregation

Background: An elevation in iron levels, together with an accumulation of α-synuclein within the oligodendrocytes, are features of the rare atypical parkinsonian disorder, Multiple System Atrophy (MSA). We have previously tested the novel compound ATH434 (formally called PBT434) in preclinical models of Parkinson’s disease and shown that it is brain-penetrant, reduces iron accumulation and iron mediated redox activity, provides neuroprotection, inhibits alpha synuclein aggregation and lowers the tissue levels of alpha synuclein. The compound was also well-tolerated in a first-in-human oral dosing study in healthy and older volunteers with a favorable, dose-dependent pharmacokinetic profile. Objective: To evaluate the efficacy of ATH434 in a mouse MSA model. Methods: The PLP-α-syn transgenic mouse overexpresses α-synuclein, demonstrates oligodendroglial pathology, and manifests motor and non-motor aspects of MSA. Animals were provided ATH434 (3, 10, or 30 mg/kg/day spiked into their food) or control food for 4 months starting at 12 months of age and were culled at 16 months. Western blot was used to assess oligomeric and urea soluble α-synuclein levels in brain homogenates, whilst stereology was used to quantitate the number of nigral neurons and glial cell inclusions (GCIs) present in the substantia nigra pars compacta. Results: ATH434 reduced oligomeric and urea soluble α-synuclein aggregation, reduced the number of GCIs, and preserved SNpc neurons. In vitro experiments suggest that ATH434 prevents the formation of toxic oligomeric species of synuclein. Conclusion: ATH434 is a promising small molecule drug candidate that has potential to move forward to trial for treating MSA.

Analysis of alpha-synuclein aggregation and associated pathologies in a cellular model of multiple system atrophy

2005 ◽  
Vol 32 (06) ◽  
Author(s):  
G Fillon ◽  
M Neumann ◽  
R Zufferey ◽  
P Aebischer ◽  
HA Kretzschmar ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Alpha Synuclein ◽  
Cellular Model ◽  
Alpha Synuclein Aggregation

scholarly journals Cryo-EM structure of alpha-synuclein fibrils amplified by PMCA from PD and MSA patient brains

2021 ◽  
Author(s):  
Domenic Burger ◽  
Alexis Fenyi ◽  
Luc Bousset ◽  
Henning Stahlberg ◽  
Ronald Melki
Keyword(s):  
Multiple System Atrophy ◽  
Parkinson Disease ◽  
Neurodegenerative Diseases ◽  
Protein Misfolding ◽  
Brain Homogenate ◽  
Alpha Synuclein ◽  
Water Interface ◽  
Control Brain ◽  
Air Water Interface

Synucleinopathies are neurodegenerative diseases related to the aggregation of the protein alpha-synuclein (aSyn). Among these diseases, Parkinson disease (PD) and multiple system atrophy (MSA) are most prevalent. aSyn can readily form different fibrillar polymorphs, if exposed to an air-water interface or by templating with pre-existing fibrils. We here report the structures of three fibrillar polymorphs that were obtained after seeding monomeric aSyn with PD and MSA patients brain homogenates using protein misfolding cyclic amplification (PMCA). Seeding with a control brain homogenate did not produce fibrils, and seeding with other in vitro generated fibrillar polymorphs as a control faithfully produced polymorphs of a different type. The here determined fibril structures from PD and MSA brain tissue represent new folds, which partly resemble that of previously reported in vitro generated fibrils from Y39 phosphorylated aSyn protein. The relevance of these fibrils for synucleinopathies in humans remains to be further investigated.

scholarly journals CLR01 protects dopaminergic neurons in vitro and in mouse models of Parkinson’s disease

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nora Bengoa-Vergniory ◽  
Emilie Faggiani ◽  
Paula Ramos-Gonzalez ◽  
Ecem Kirkiz ◽  
Natalie Connor-Robson ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clinical Investigation ◽  
Induced Pluripotent Stem Cell ◽  
Alpha Synuclein ◽  
Dopamine Neurons ◽  
Molecular Tweezers ◽  
Alpha Synuclein Aggregation

Abstract Parkinson’s disease (PD) affects millions of patients worldwide and is characterized by alpha-synuclein aggregation in dopamine neurons. Molecular tweezers have shown high potential as anti-aggregation agents targeting positively charged residues of proteins undergoing amyloidogenic processes. Here we report that the molecular tweezer CLR01 decreased aggregation and toxicity in induced pluripotent stem cell-derived dopaminergic cultures treated with PD brain protein extracts. In microfluidic devices CLR01 reduced alpha-synuclein aggregation in cell somas when axonal terminals were exposed to alpha-synuclein oligomers. We then tested CLR01 in vivo in a humanized alpha-synuclein overexpressing mouse model; mice treated at 12 months of age when motor defects are mild exhibited an improvement in motor defects and a decreased oligomeric alpha-synuclein burden. Finally, CLR01 reduced alpha-synuclein-associated pathology in mice injected with alpha-synuclein aggregates into the striatum or substantia nigra. Taken together, these results highlight CLR01 as a disease-modifying therapy for PD and support further clinical investigation.

scholarly journals Reducing C-terminal truncation mitigates synucleinopathy and neurodegeneration in a transgenic model of multiple system atrophy

2016 ◽  
Vol 113 (34) ◽  
pp. 9593-9598 ◽  
Author(s):  
Fares Bassil ◽  
Pierre-Olivier Fernagut ◽  
Erwan Bezard ◽  
Alain Pruvost ◽  
Thierry Leste-Lasserre ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Neurodegenerative Disorder ◽  
Disease Onset ◽  
Neuronal Cell ◽  
Alpha Synuclein ◽  
Motor Deficits ◽  
Neuroprotective Effects ◽  
Caspase 1

Multiple system atrophy (MSA) is a sporadic orphan neurodegenerative disorder. No treatment is currently available to slow down the aggressive neurodegenerative process, and patients die within a few years after disease onset. The cytopathological hallmark of MSA is the accumulation of alpha-synuclein (α-syn) aggregates in affected oligodendrocytes. Several studies point to α-syn oligomerization and aggregation as a mediator of neurotoxicity in synucleinopathies including MSA. C-terminal truncation by the inflammatory protease caspase-1 has recently been implicated in the mechanisms that promote aggregation of α-syn in vitro and in neuronal cell models of α-syn toxicity. We present here an in vivo proof of concept of the ability of the caspase-1 inhibitor prodrug VX-765 to mitigate α-syn pathology and to mediate neuroprotection in proteolipid protein α-syn (PLP-SYN) mice, a transgenic mouse model of MSA. PLP-SYN and age-matched wild-type mice were treated for a period of 11 wk with VX-765 or placebo. VX-765 prevented motor deficits in PLP-SYN mice compared with placebo controls. More importantly, VX-765 was able to limit the progressive toxicity of α-syn aggregation by reducing its load in the striatum of PLP-SYN mice. Not only did VX-765 reduce truncated α-syn, but it also decreased its monomeric and oligomeric forms. Finally, VX-765 showed neuroprotective effects by preserving tyrosine hydroxylase-positive neurons in the substantia nigra of PLP-SYN mice. In conclusion, our results suggest that VX-765, a drug that was well tolerated in a 6 wk-long phase II trial in patients with epilepsy, is a promising candidate to achieve disease modification in synucleinopathies by limiting α-syn accumulation.

scholarly journals Queuine, a bacterial derived hypermodified nucleobase, shows protection in in vitro models of neurodegeneration

2021 ◽  
Author(s):  
Patricia Richard ◽  
Xavier Manière ◽  
Lucie Kozlowski ◽  
Hélène Guillorit ◽  
Patrice Garnier ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Therapeutic Potential ◽  
Mrna Translation ◽  
Alpha Synuclein ◽  
In Vitro Models ◽  
Wobble Position ◽  
Mitochondrial Defects ◽  
Alpha Synuclein Aggregation ◽  
The Brain

AbstractGrowing evidence suggests that human gut bacteria, comprising the microbiome that communicates with the brain through the so-called ‘gut-brain-axis’, are linked to neurodegenerative disorders. Imbalances in the microbiome of Parkinson’s disease (PD) and Alzheimer’s disease (AD) patients have been detected in several studies. Queuine is a hypermodified nucleobase enriched in the brain and exclusively produced by bacteria and salvaged by humans through their gut epithelium. Queuine replaces guanine at the wobble position of tRNAs with GUN anticodons and promotes efficient cytoplasmic and mitochondrial mRNA translation.To elucidate whether queuine could facilitate protein folding and prevent aggregation and mitochondrial defects, hallmarks of neurodegenerative disorders, we tested the effect of chemically synthesized queuine, STL-101, in several in vitro models of neurodegeneration. Treatment with STL-101 led to increased neuronal survival as well as a significant decrease in hyper-phosphorylated alpha-synuclein, a marker of alpha-synuclein aggregation in a PD model and a decrease in tau hyperphosphorylation in an AD model. Our work has identified a new role for queuine in neuroprotection uncovering a therapeutic potential for STL-101 in neurological disorders.

scholarly journals Looking for a generic inhibitor of amyloid-like fibril formation among flavone derivatives

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1271 ◽  
Author(s):  
Tomas Šneideris ◽  
Lina Baranauskienė ◽  
Jonathan G. Cannon ◽  
Rasa Rutkienė ◽  
Rolandas Meškys ◽  
...  
Keyword(s):  
Beta Amyloid ◽  
Structural Features ◽  
Alpha Synuclein ◽  
Fibril Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Amyloid Fibril Formation ◽  
Flavone Derivatives ◽  
Alpha Synuclein Aggregation

A range of diseases is associated with amyloid fibril formation. Despite different proteins being responsible for each disease, all of them share similar features including beta-sheet-rich secondary structure and fibril-like protein aggregates. A number of proteins can form amyloid-like fibrilsin vitro, resembling structural features of disease-related amyloids. Given these generic structural properties of amyloid and amyloid-like fibrils, generic inhibitors of fibril formation would be of interest for treatment of amyloid diseases. Recently, we identified five outstanding inhibitors of insulin amyloid-like fibril formation among the pool of 265 commercially available flavone derivatives. Here we report testing of these five compounds and of epi-gallocatechine-3-gallate (EGCG) on aggregation of alpha-synuclein and beta-amyloid. We used a Thioflavin T (ThT) fluorescence assay, relying on halftimes of aggregation as the measure of inhibition. This method avoids large numbers of false positive results. Our data indicate that four of the five flavones and EGCG inhibit alpha-synuclein aggregation in a concentration-dependent manner. However none of these derivatives were able to increase halftimes of aggregation of beta-amyloid.

scholarly journals Influence of Energy Deficiency on the Molecular Processes of Substantia Nigra Pars Compacta Cell for Understanding Parkinsonian Neurodegeneration: A Comprehensive Biophysical Computational Model

2020 ◽  
Author(s):  
Vignayanandam R. Muddapu ◽  
V. Srinivasa Chakravarthy
Keyword(s):  
Substantia Nigra ◽  
Computational Model ◽  
Cell Loss ◽  
Alpha Synuclein ◽  
Cellular Systems ◽  
Integrated Modelling ◽  
Substantia Nigra Pars Compacta ◽  
Energy Deficiency ◽  
Proposed Model ◽  
Alpha Synuclein Aggregation

ABSTRACTParkinson’s disease (PD) is the second most prominent neurodegenerative disease around the world. Although it is known that PD is caused by the loss of dopaminergic cells in substantia nigra pars compacta (SNc), the decisive cause of this inexorable cell loss is not clearly elucidated. We hypothesize that “Energy deficiency at a sub-cellular/cellular/systems level can be a common underlying cause for SNc cell loss in PD.” Here, we propose a comprehensive computational model of SNc cell which helps us to understand the pathophysiology of neurodegeneration at subcellular level in PD. The proposed model incorporates a rich vein of molecular dynamics related to SNc neurons such as ion channels, active pumps, ion exchangers, dopamine turnover processes, energy metabolism pathways, calcium buffering mechanisms, alpha-synuclein aggregation, Lewy body formation, reactive oxygen species (ROS) production, levodopa uptake, and apoptotic pathways. The proposed model was developed and calibrated based on experimental data. The influx of glucose and oxygen into the model was controlled, and the consequential ATP variations were observed. Apart from this, the dynamics of other molecular players (alpha-synuclein, ROS, calcium, and dopamine) known to play an important role in PD pathogenesis are also studied. The aim of the study was to see how deficits in supply of energy substrates (glucose and oxygen) lead to a deficit in ATP, and furthermore, deficits in ATP are the common factor underlying the pathological molecular-level changes including alpha-synuclein aggregation, ROS formation, calcium elevation, and dopamine dysfunction. The model suggests that hypoglycemia plays a more crucial role in leading to ATP deficits than hypoxia. We believe that the proposed model provides an integrated modelling framework to understand the neurodegenerative processes underlying PD.

scholarly journals Seeded propagation of alpha-synuclein aggregation in mouse brain using protein misfolding cyclic amplification

2019 ◽  
Author(s):  
Simon Nicot ◽  
Jérémy Verchère ◽  
Maxime Belondrade ◽  
Charly Mayran ◽  
Dominique Bétemps ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Protein Misfolding ◽  
Wild Type Mouse ◽  
Molecular Study ◽  
Alpha Synuclein ◽  
Proteinase K ◽  
Wild Type ◽  
Protein Misfolding Cyclic Amplification ◽  
Alpha Synuclein Aggregation

Alpha-synuclein (α-syn) protein aggregation is associated with several neurodegenerative disorders collectively referred to as synucleinopathies, including Parkinson disease. We used protein misfolding cyclic amplification (PMCA) to study α-syn aggregation in brain homogenates of wild-type or transgenic mice expressing normal (D line) or A53T mutant (M83 line) human α-syn. We found that sonication-incubation cycles of M83 mouse brain gradually produce large quantities of SDS-resistant α-syn aggregates, involving both human and mouse proteins. These PMCA products, containing partially proteinase K resistant α-syn species, are competent to accelerate the onset of neurological symptoms after intracerebral inoculation to young M83 mice and to seed aggregate formation of α-syn following PMCA, including in D and wild-type mouse brain substrates. Our data indicate that similar to prions, PMCA can reproduce some characteristics of α-syn aggregation and seeded-propagation in vitro in a complex milieu. This opens new opportunities for the molecular study of synucleinopathies.

scholarly journals Small Molecules Attenuate the Interplay between Conformational Fluctuations, Early Oligomerization and Amyloidosis of Alpha Synuclein

2017 ◽  
Author(s):  
Amrita Kundu ◽  
Sumanta Ghosh ◽  
Krishnananda Chattopadhyay
Keyword(s):  
Single Molecule ◽  
Early Stage ◽  
Neuroblastoma Cells ◽  
Alpha Synuclein ◽  
Inhibitor Molecule ◽  
Transient Nature ◽  
Fluorescence Measurements ◽  
Late Event ◽  
Alpha Synuclein Aggregation

AbstractAggregation of alpha synuclein has strong implications in Parkinson’s disease. The heterogeneity of folding/aggregation landscape and transient nature of the early intermediates result in difficulty in developing a successful therapeutic intervention. Here we used fluorescence measurements at ensemble and single molecule resolution to study how the late and early events of alpha synuclein aggregation modulate each other. The in-vitro aggregation data was complemented using measurements inside live neuroblastoma cells by employing a small molecule labeling technique. An inhibitor molecule (arginine), which delayed the late event of amyloidosis, was found to bind to the protein, shifting the early conformational fluctuations towards a compact state. In contrast, a facilitator of late aggregation (glutamate), was found to be excluded from the protein surface. The presence of glutamate was found to speed up the oligomer formation at the early stage. We found that the effects of the inhibitor and facilitator were additive and as a result they maintained a ratio at which they cancelled each other’s influence on different stages of alpha synuclein aggregation.

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