alpha-synuclein and Movement-Disorders

The two commonest groups of neurodegenerative disorders causing movement disorders are synucleinopathies and tauopathies. These disorders are characterised by the accumulation of abnormally misfolded forms of α-synuclein and tau proteins. Our current understanding of their pathogenesis suggests that extracellular forms of these proteins are of major relevance to the mechanism of pathology propagation throughout the brain and disease progression. The most novel approaches to find disease-modifying therapies aim to reduce or block these forms of tau and α-synuclein. This article reviews therapeutic strategies targeting α-synuclein and tau protein which have entered clinical development.

Topics: alpha-Synuclein; Humans; Movement Disorders; Neurodegenerative Diseases; tau Proteins; Tauopathies

Parkinson's disease (PD) is an adult onset neurodegenerative disease that is characterized by selective degeneration of neurons primarily in the substantia nigra. At present, the pathogenesis of PD is incompletely understood and there are no neuroprotective treatments available. Accurate animal models of PD provide the opportunity to elucidate disease mechanisms and identify therapeutic targets. This review focuses on C. elegans models of PD, including both genetic and toxicant models. This microscopic worm offers several advantages for the study of PD including ease of genetic manipulation, ability to complete experiments rapidly, low cost, and ability to perform large scale screens for disease modifiers. A number of C. elegans models of PD have been generated including transgenic worms that express α-synuclein or LRRK2, and worms with deletions in PRKN/pdr-1, PINK1/pink-1, DJ-1/djr-1.1/djr-1.2 and ATP13A2/catp-6. These worms have been shown to exhibit multiple phenotypic deficits including the loss of dopamine neurons, disruption of dopamine-dependent behaviors, increased sensitivity to stress, age-dependent aggregation, and deficits in movement. As a result, these phenotypes can be used as outcome measures to gain insight into disease pathogenesis and to identify disease modifiers. In this way, C. elegans can be used as an experimental tool to elucidate mechanisms involved in PD and to find novel therapeutic targets that can subsequently be validated in other models.

Topics: alpha-Synuclein; Animals; Animals, Genetically Modified; Antiparkinson Agents; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Disease Models, Animal; Dopaminergic Neurons; Drug Evaluation, Preclinical; Feeding Behavior; Gene-Environment Interaction; Genes, Reporter; Humans; Mitochondria; Movement Disorders; Nerve Degeneration; Neurotoxins; Parkinsonian Disorders; Phenotype; Protein Aggregation, Pathological; Recombinant Fusion Proteins; RNA Interference; Species Specificity

Parkinson's disease (PD) is a neurodegenerative disorder whose aetiology remains unclear: degeneration involves several neurotransmission systems, resulting in a heterogeneous disease characterized by motor and non-motor symptoms. PD causes progressive disability that responds only to symptomatic therapies. Future advances include neuroprotective strategies for use in at-risk populations before the clinical onset of disease, hence the continuing need to identify reliable biomarkers that can facilitate the clinical diagnosis of PD. In this evaluative review, we summarize information on potential diagnostic biomarkers for use in the clinical and preclinical stages of PD.

Topics: alpha-Synuclein; Biomarkers; Brain; Cognition Disorders; Constipation; Depression; Early Diagnosis; Genetic Predisposition to Disease; Humans; Inflammation; Levodopa; Metabolomics; Microbiota; Movement Disorders; Neuroimaging; Olfaction Disorders; Parkinson Disease; REM Sleep Behavior Disorder; Symptom Assessment; Vision Disorders

In recent years progress has been made in the detection and evaluation of nonmotor symptoms in Parkinson's disease. The pathophysiology is better understood and new treatment is available, which will be discussed in this review.. The most intriguing recent finding is the fact that Parkinson's disease may be a spreading disease. From the environment a toxin, bacteria, or virus may start in genetically susceptible patients a cascade of α-synuclein aggregation which reaches via the olfactory and the enteric system of the gut the brain where further spreading causes symptoms, such as sleep disturbances, motor impairment, and neuropsychiatric symptoms. New treatment should address the abnormal α-synuclein folding. If this would be achieved premotor signs, such as hyposmia, rapid eye movement-sleep behavior disorder, constipation, or depression may be a kind of biomarkers which allow together with other diagnostic tools, such as parenchymal sonography, iodobenzamide-scintigraphy and dopamine transporter scans the prediction whether somebody might be under way to develop the full-blown Parkinson's disease syndrome.. Parkinson's disease seems to be a spreading disease which causes not only a dopaminergic deficit as major cause for the movement disorder but also impairs function of many other brain centers which leads to a multitransmitter malfunction.

Topics: alpha-Synuclein; Autonomic Nervous System Diseases; Cardiovascular Diseases; Dyskinesias; Early Diagnosis; Erectile Dysfunction; Fatigue; Gastrointestinal Diseases; Humans; Male; Mental Disorders; Movement Disorders; Olfaction Disorders; Pain; Parkinson Disease; Sleep Wake Disorders; Urologic Diseases

Research in movement disorders in 2012 has improved our understanding of the pathogenic mechanisms of disease and led to development of potential novel therapeutic approaches. Key advances were linked to mechanisms underlying spread of neurodegenerative pathology, immunotherapy, stem cells, genetics and deep brain stimulation in parkinsonism and related disorders.

Topics: alpha-Synuclein; Animals; Deep Brain Stimulation; Humans; Immunotherapy; Mice; Mice, Transgenic; Movement Disorders; Neurodegenerative Diseases; Neuroimaging; Parkinsonian Disorders; Pluripotent Stem Cells; Stem Cell Transplantation

Topics: alpha-Synuclein; Animals; Humans; Movement Disorders; Nerve Tissue Proteins; Neurodegenerative Diseases; Synucleins; tau Proteins

Linkage of the Huntington's disease gene to chromosome 4 in 1983 marked the birth of modern genetics in movement disorders. The discovery that an expanded trinucleotide DNA repeat was central to the mechanism of this disease has been repeated over and over in a growing list of inherited ataxias. In 1997, a different mutation and genetic mechanism was discovered in a severe type of generalized primary torsion dystonia - Oppenheim's dystonia. Before this, only the genetic cause for rare metabolic dystonias was known, notably dopa-responsive (Segawa's) dystonia. In the same year, from the identification of mutation in the alpha-synuclein gene in rare pedigrees with autosomal dominant parkinsonism, arose the concept that Parkinson's disease may be part of a broader group of 'synucleinopathies', in which there is a fundamental defect in protein processing. In the following year, mutations in autosomal recessive juvenile onset parkinsonism were found in a gene called 'parkin'. Parkin mutations are a more common cause of parkinsonism than the rare alpha-synuclein mutations, particularly in young-onset disease. However, a most important understanding, occurring in the last year, has been the relationship between the parkin gene product, alpha-synuclein and abnormal protein degradation in the cell. A unified theory of neuronal death in Parkinson's disease is emerging, pointing to potential new therapies in the future.

Topics: alpha-Synuclein; Carrier Proteins; Chromosome Mapping; Chromosomes, Human; Dystonic Disorders; Friedreich Ataxia; Genes, Dominant; Genes, Recessive; Humans; Huntingtin Protein; Huntington Disease; Ligases; Minisatellite Repeats; Molecular Chaperones; Movement Disorders; Nerve Tissue Proteins; Nuclear Proteins; Parkinson Disease; Spinocerebellar Ataxias; Synucleins; Ubiquitin-Protein Ligases

Multiple system atrophy (MSA) is a sporadic adult-onset rare neurodegenerative synucleinopathy for which counteracting central nervous system insulin resistance bears the potential of being neuroprotective. G-protein-(heterotrimeric guanine nucleotide-binding protein)-coupled receptor kinase 2 (GRK2) is emerging as a physiologically relevant inhibitor of insulin signaling.. We tested whether lowering brain GRK2 abundance may reverse insulin-resistance.. We lowered brain GRK2 abundance through viral-mediated delivery of a GRK2-specific miRNA and quantified the reversion of a developing or an established insulin-resistant phenotype using the transgenic PLP-SYN mouse model of MSA.. Viral vector delivery of a GRK2 miRNA demonstrated a neuroprotective capacity when administered (1) in utero intracerebroventricularly in developing PLP-SYN mice and (2) intrastriatally in adult PLP-SYN mice. Decreased striatal GRK2 levels correlated in both designs with neuroprotection of the substantia nigra dopamine neurons, reduction in high-molecular-weight species of α-synuclein, and reduced insulin resistance.. These data support GRK2 as a potential therapeutic target in MSA. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Topics: alpha-Synuclein; Animals; Disease Models, Animal; Insulin Resistance; Insulins; Mice; Mice, Transgenic; MicroRNAs; Movement Disorders; Multiple System Atrophy

Peripheral administration (oral, intranasal, intraperitoneal, intravenous) of assembled A53T α-synuclein induced synucleinopathy in heterozygous mice transgenic for human mutant A53T α-synuclein (line M83). The same was the case when cerebellar extracts from a case of multiple system atrophy with type II α-synuclein filaments were administered intraperitoneally, intravenously or intramuscularly. We observed abundant immunoreactivity for pS129 α-synuclein in nerve cells and severe motor impairment, resulting in hindlimb paralysis and shortened lifespan. Filaments immunoreactive for pS129 α-synuclein were in evidence. A 70% loss of motor neurons was present five months after an intraperitoneal injection of assembled A53T α-synuclein or cerebellar extract with type II α-synuclein filaments from an individual with a neuropathologically confirmed diagnosis of multiple system atrophy. Microglial cells changed from a predominantly ramified to a dystrophic appearance. Taken together, these findings establish a close relationship between the formation of α-synuclein inclusions in nerve cells and neurodegeneration, accompanied by a shift in microglial cell morphology. Propagation of α-synuclein inclusions depended on the characteristics of both seeds and transgenically expressed protein.

Topics: Aged; alpha-Synuclein; Animals; Animals, Genetically Modified; Hindlimb; Humans; Immunohistochemistry; Male; Mice, Neurologic Mutants; Microglia; Motor Neurons; Movement Disorders; Multiple System Atrophy; Mutation; Neurodegenerative Diseases; Neurons; Paralysis

α-synuclein (α-syn) aggregation can lead to degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) as invariably observed in patients with Parkinson's Disease (PD). The co-chaperone DNAJB6 has previously been found to be expressed at higher levels in PD patients than in control subjects and was also found in Lewy bodies. Our previous experiments showed that knock out of DNAJB6 induced α-syn aggregation in cellular level. However, effects of overexpression of DNAJB6 against α-syn aggregation remains to be investigated.. We used a α-syn CFP/YFP HEK293 FRET cell line to investigate the effects of overexpression of DNAJB6 in cellular level. α-syn aggregation was induced by transfection α-syn preformed fibrils (PPF), then was measured FRET analysis. We proceeded to investigate if DNAJB6b can impair α-syn aggregation and toxicity in an animal model and used adeno associated vira (AAV6) designed to overexpress of human wt α-syn, GFP-DNAJB6 or GFP in rats. These vectors were injected into the SNpc of the rats, unilaterally. Rats injected with vira to express α-syn along with GFP in the SNpc where compared to rats expressing α-syn and GFP-DNAJB6. We evaluated motor functions, dopaminergic cell death, and axonal degeneration in striatum.. We show that DNAJB6 prevent α-syn aggregation induced by α-syn PFF's, in a cell culture model. In addition, we observed α-syn overexpression caused dopaminergic cell death and that this was strongly reduced by co-expression of DNAJB6b. The lesion caused by α-syn overexpression resulted in behavior deficits, which increased over time as seen in stepping test, which was rescued by co-expression of DNAJB6b.. We here demonstrate for the first time that DNAJB6 is a strong suppressor of α-syn aggregation in cells and in animals and that this results in a suppression of dopaminergic cell death and PD related motor deficits in an animal model of PD.

Topics: alpha-Synuclein; Animals; Axons; Cell Death; Disease Models, Animal; Dopaminergic Neurons; Female; Gene Expression Regulation; HEK293 Cells; HSP40 Heat-Shock Proteins; Humans; Molecular Chaperones; Movement Disorders; Neostriatum; Nerve Tissue Proteins; Parkinson Disease; Psychomotor Performance; Rats; Rats, Sprague-Dawley

In Parkinson`s disease (PD), the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta is associated with Lewy bodies arising from the accumulation of alpha-synuclein protein which leads ultimately to movement impairment. While PD has been considered a disease of the DA neurons, a glial contribution, in particular that of astrocytes, in PD pathogenesis is starting to be uncovered. Here, we report findings from astrocytes derived from induced pluripotent stem cells of LRRK2 G2019S mutant patients, with one patient also carrying a GBA N370S mutation, as well as healthy individuals. The PD patient astrocytes manifest the hallmarks of the disease pathology including increased expression of alpha-synuclein. This has detrimental consequences, resulting in altered metabolism, disturbed Ca

Topics: alpha-Synuclein; Astrocytes; Brain; Calcium; Dopaminergic Neurons; Glucosylceramidase; Humans; Induced Pluripotent Stem Cells; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Lewy Bodies; Metabolic Networks and Pathways; Movement Disorders; Mutation; Neuroglia; Parkinson Disease

Microglia-mediated neuroinflammation is critical for the pathogenesis of neurodegenerative diseases, including Parkinson's disease (PD). microRNA-let-7a (miR-let-7a) targets the signal transducer and activator of transcription-3 (STAT3) and regulates microglia function. However, less is known about whether it plays a functional role in PD. In this report, by utilizing a mouse PD model induced by the overexpression of α-Synuclein (α-Syn), a pathological hallmark of PD, we found that miR-let-7a expression was downregulated, while STAT3 was synchronously activated in the substantia nigra pars compacta (SNpc). Similar results were obtained in α-Syn-treated BV-2 microglia cells cultured in vitro. Additionally, STAT3 was proven to be a direct target of miR-let-7a in BV-2 microglia cells, suggesting that miR-let-7a downregulation may contribute to STAT3 activation in α-Syn-induced mouse PD. Moreover, miR-let-7a overexpression suppressed α-Syn-induced BV-2 microglia cell activation and pro-inflammatory cytokine production, and these effects were abrogated by restoring STAT3 protein, hence establishing that miR-let-7a suppresses microglia-mediated inflammation through targeting STAT3. Lastly, miR-let-7a overexpression via injection of miR-7 mimics into mouse striatum suppressed microglia activation and reduced pro-inflammatory cytokine production, which were accompanied by relieved movement disorder and improved spatial memory deficits in α-Syn-induced PD mice. Altogether, these results may identify miR-let-7a as a negative regulator of microglia-elicited neuroinflammation, at least partially explaining its alleviating effects on PD symptoms.

Topics: 3' Untranslated Regions; alpha-Synuclein; Animals; Disease Models, Animal; Gene Expression Regulation; Humans; Inflammation; Male; Memory Disorders; Mice, Inbred C57BL; Microglia; MicroRNAs; Movement Disorders; Parkinson Disease; STAT3 Transcription Factor

MSA is a fatal neurodegenerative disease characterized by autonomic failure and severe motor impairment. Its main pathological hallmark is the accumulation of α-synuclein in oligodendrocytes, leading to glial and neuronal dysfunction and neurodegeneration. These features are recapitulated in the PLP-hαSyn mouse model expressing human α-synuclein in oligodendrocytes. At present, there is no effective disease-modifying therapy. Previous experiments have shown that the aggregation inhibitor, anle138b, reduces neurodegeneration and behavioral deficits in mouse models of other proteinopathies.. To test the therapeutic potential of anle138b in a mouse model of MSA.. Two-month-old PLP-hαSyn mice were fed over a period of 4 months with pellets containing anle138b at two different doses (0.6 and 2 g/kg) and compared to healthy controls and PLP-hαSyn mice fed with placebo pellets. At the end of the treatment, behavioral and histological analyses were performed.. We observed a reversal of motor function to healthy control levels when PLP-hαSyn mice were treated with both doses of anle138b. Histological and molecular analyses showed a significant reduction in α-synuclein oligomers and glial cytoplasmic inclusions in animals fed with anle138b compared to nontreated mice. These animals also present preservation of dopaminergic neurons and reduction in microglial activation in SN correlating with the α-synuclein reduction observed.. Anle138b reduces α-synuclein accumulation in PLP-hαSyn mice, leading to neuroprotection, reduction of microglial activation, and preservation of motor function supporting the use of anle138b in a future clinical trial for MSA. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Topics: alpha-Synuclein; Animals; Benzodioxoles; Disease Models, Animal; Mice, Transgenic; Movement Disorders; Multiple System Atrophy; Nerve Degeneration; Neuroglia; Neurons; Oligodendroglia; Pyrazoles

α-Synucleinopathies are neurodegenerative diseases that are characterized pathologically by α-synuclein inclusions in neurons and glia. The pathologic contribution of glial α-synuclein in these diseases is not well understood. Glial α-synuclein may be of particular importance in multiple system atrophy (MSA), which is defined pathologically by glial cytoplasmic α-synuclein inclusions. We have previously described Drosophila models of neuronal α-synucleinopathy, which recapitulate key features of the human disorders. We have now expanded our model to express human α-synuclein in glia. We demonstrate that expression of α-synuclein in glia alone results in α-synuclein aggregation, death of dopaminergic neurons, impaired locomotor function, and autonomic dysfunction. Furthermore, co-expression of α-synuclein in both neurons and glia worsens these phenotypes as compared to expression of α-synuclein in neurons alone. We identify unique transcriptomic signatures induced by glial as opposed to neuronal α-synuclein. These results suggest that glial α-synuclein may contribute to the burden of pathology in the α-synucleinopathies through a cell type-specific transcriptional program. This new Drosophila model system enables further mechanistic studies dissecting the contribution of glial and neuronal α-synuclein in vivo, potentially shedding light on mechanisms of disease that are especially relevant in MSA but also the α-synucleinopathies more broadly.

Topics: alpha-Synuclein; Animals; Animals, Genetically Modified; Cell Death; Constipation; Disease Models, Animal; Dopaminergic Neurons; Drosophila; Humans; Movement Disorders; Nerve Degeneration; Neurodegenerative Diseases; Neuroglia; Protein Aggregation, Pathological; Transcription, Genetic; Transcriptome

Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disorder characterized by widespread oligodendroglial cytoplasmic inclusions of filamentous α-synuclein, and neuronal loss in autonomic centres, basal ganglia and cerebellar circuits. It has been suggested that primary oligodendroglial α-synucleinopathy may represent a trigger in the pathogenesis of MSA, but the mechanisms underlying selective vulnerability and disease progression are unclear. The post-mortem analysis of MSA brains provides a static final picture of the disease neuropathology, but gives no clear indication on the sequence of pathogenic events in MSA. Therefore, alternative methods are needed to address these issues. We investigated selective vulnerability and disease progression in the transgenic PLP-α-syn mouse model of MSA characterized by targeted oligodendroglial α-synuclein overexpression aiming to provide a neuropathological correlate of motor deterioration. We show progressive motor deficits that emerge at 6 months of age and deteriorate up to 18 months of follow-up. The motor phenotype was associated with dopaminergic cell loss in the substantia nigra pars compacta at 6 months, followed by loss of striatal dopaminergic terminals and DARPP32-positive medium sized projection neurons at 12 months. Olivopontocerebellar motor loops remained spared in the PLP-α-syn model of MSA. These findings replicate progressive striatonigral degeneration underlying Parkinson-variant MSA. The initiation of the degenerative process was linked to an increase of soluble oligomeric α-synuclein species between 2 and 6 months. Early region-specific α-synuclein-associated activation profile of microglia was found in MSA substantia nigra. The role of abnormal neuroinflammatory signalling in disease progression was further supported by increased levels of CD68, CCL3, CCL5 and M-CSF with a peak in aged PLP-α-syn mice. In summary, transgenic PLP-α-syn mice show a distinctive oligodendroglial α-synucleinopathy that is associated with progressive striatonigral degeneration linked to abnormal neuroinflammatory response. The model provides a relevant tool for preclinical therapeutic target discovery for human Parkinson-variant MSA.

Topics: Age Factors; alpha-Synuclein; Analysis of Variance; Animals; Antigens, CD; Calcium-Binding Proteins; Disease Models, Animal; Gene Expression Regulation; Humans; Mice; Mice, Transgenic; Microfilament Proteins; Microglia; Microscopy, Confocal; Movement Disorders; Multiple System Atrophy; Muscle Strength; Myelin Proteolipid Protein; Nerve Tissue Proteins; Postural Balance; Sensation Disorders; Striatonigral Degeneration

Alpha-synuclein is a component of Lewy bodies, the pathological hallmark of Parkinson's disease (PD), and is also mutated in familial PD. Here, by extensively analyzing PD patient brains and neurons, and fly models, we show that alpha-synuclein accumulation results in upregulation of Miro protein levels. Miro is a motor/adaptor on the outer mitochondrial membrane that mediates mitochondrial motility, and is removed from damaged mitochondria to facilitate mitochondrial clearance via mitophagy. PD patient neurons abnormally accumulate Miro on the mitochondrial surface leading to delayed mitophagy. Partial reduction of Miro rescues mitophagy phenotypes and neurodegeneration in human neurons and flies. Upregulation of Miro by alpha-synuclein requires an interaction via the N-terminus of alpha-synuclein. Our results highlight the importance of mitochondria-associated alpha-synuclein in human disease, and present Miro as a novel therapeutic target.

Topics: alpha-Synuclein; Animals; Behavior, Animal; Brain; Cell Differentiation; Drosophila melanogaster; Drosophila Proteins; Humans; Induced Pluripotent Stem Cells; Mitochondria; Mitophagy; Movement Disorders; Mutation; Nerve Degeneration; Neurons; Parkinson Disease; rho GTP-Binding Proteins; Signal Transduction; Up-Regulation

Phosphorylated α-synuclein (p-syn) in skin nerves mainly in the proximal sites is a promising neurodegenerative biomarker for idiopathic Parkinson disease (IPD). However, the p-syn spine distribution particularly in patients with unilateral motor dysfunctions remains undefined. This study aimed to investigate in IPD p-syn differences between left and right cervical spine sites in patients with prevalent unilateral motor symptoms, and cervical and thoracic spine sites in patients with bilateral motor symptoms. We enrolled 28 IPD patients fulfilling clinical diagnostic criteria associated with abnormal nigro-striatal DatScan and cardiac MIBG: 15 with prevalently unilateral motor symptoms demonstrated by DatScan; 13 with bilateral motor symptoms and DatScan abnormalities. Patients underwent skin biopsy searching for intraneural p-syn deposits: skin samples were taken from C7 paravertebral left and right sites in unilateral patients and from cervical (C7) and thoracic (Th12) paravertebral spine regions in bilateral patients. Unilateral patients displayed 20% of abnormal p-syn deposits in the affected motor site, 60% in both sites and 20% only in the non-affected site. P-syn was found in all patients in C7 but in only 62% of patients in Th12. Our data showed that cervical p-syn deposits displayed a uniform distribution between both sides not following the motor dysfunction in unilateral patients, and skin nerve p-syn deposits demonstrated a spine gradient with the cervical site expressing the highest positivity.

Topics: Aged; Aged, 80 and over; alpha-Synuclein; Biomarkers; Biopsy; Dopamine Plasma Membrane Transport Proteins; Female; Functional Laterality; Humans; Male; Middle Aged; Movement Disorders; Neostriatum; Parkinson Disease; Phosphorylation; Positron-Emission Tomography; Skin; Substantia Nigra

The abnormal accumulation of alpha-synuclein (α-syn) has been linked to a number of neurodegenerative disorders, the most noteworthy of which is Parkinson's disease. Alpha-synuclein itself is not toxic and fulfills various physiological roles in the central nervous system. However, specific types of aggregates have been shown to be toxic, and metals have been linked to the assembly of these toxic aggregates. In this paper, we have characterized a transgenic mouse that overexpresses the A53T mutation of human α-syn, specifically assessing cognition, motor performance, and subtle anatomical markers that have all been observed in synucleinopathies in humans. We hypothesized that treatment with the moderate-affinity metal chelator, clioquinol (CQ), would reduce the interaction between metals and α-syn to subsequently improve the phenotype of the A53T animal model. We showed that CQ prevents an iron-synuclein interaction, the formation of urea-soluble α-syn aggregates, α-syn-related substantia nigra pars compacta cell loss, reduction in dendritic spine density of hippocampal and caudate putamen medium spiny neurons, and the decline in motor and cognitive function. In conclusion, our data suggests that CQ is capable of mitigating the pathological metal/α-syn interactions, suggesting that the modulation of metal ions warrants further study as a therapeutic approach for the synucleinopathies.

Topics: alpha-Synuclein; Animals; Brain; Clioquinol; Cognition Disorders; Disease Models, Animal; Exploratory Behavior; Humans; Maze Learning; Mice; Mice, Transgenic; Movement Disorders; Mutation; Protein Aggregation, Pathological; Recognition, Psychology; Silver Staining; Spatial Learning

To investigate whether certain CSF biomarkers at baseline can predict future progression of motor symptoms and cognitive decline in patients with Parkinson disease (PD).. Patients and controls were recruited from hospitals in southern Sweden as part of the prospective and longitudinal Swedish BioFinder Study. In the present study, we included 42 patients with PD and 69 controls who had clinical assessment and lumbar puncture at baseline. Baseline CSF samples were analyzed for α-synuclein (αSyn), β-amyloid 1-42 (Aβ42), tau, phosphorylated tau, and neurofilament light. Associations between CSF markers at baseline and change in clinical characteristics after 2 years of follow-up were investigated using multivariate models adjusting for age, sex, disease duration, and levodopa-equivalent daily dose.. Higher levels of αSyn within the PD group were associated with progression of motor symptoms and cognitive decline over 2 years, indicated by significant relationships between αSyn and change in Hoehn and Yahr (β = 0.394, p = 0.043), Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III) (β = 0.449, p = 0.013), Timed Up and Go (β = 0.406, p = 0.023), and A Quick Test of Cognitive Speed (β = 0.423, p = 0.018). Lower levels of Aβ42 were associated with worsening of performance on delayed memory recall (F = 5.834, p = 0.022). Finally, high levels of phosphorylated tau were associated with worsening in motor symptoms (UPDRS-III, β = 0.350, p = 0.045; Hoehn and Yahr, β = 0.366, p = 0.038).. We found evidence of a link between higher levels of αSyn at baseline and worsening of motor symptoms and cognitive speed over 2 years in PD. Increased αSyn might be a marker of more intense synaptic degeneration in PD. The results indicate that cortical amyloid pathology (low CSF Aβ42) is associated with memory decline.

Topics: Aged; alpha-Synuclein; Amyloid beta-Peptides; Biomarkers; Case-Control Studies; Cognition Disorders; Disease Progression; Female; Humans; Male; Middle Aged; Movement Disorders; Neurofilament Proteins; Neuropsychological Tests; Parkinson Disease; Peptide Fragments; Phosphorylation; Prognosis; Prospective Studies; Sweden; tau Proteins

To investigate the effects of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG) on the memory and movement functions and its mechanisms related to synapses and α-synuclein in aged mice.. The memory ability of mice was detected by step-through passive avoidance task. The movement function was measured by the pole test and rotarod test. Transmission electron microscopy was used to observe the synaptic ultrastructure. Western blotting was applied to measure the expression of synapse-related proteins and α-synuclein.. Intragastrical administration of TSG for 3 months significantly improved the memory and movement functions in aged mice. TSG treatment obviously protected the synaptic ultrastructure and increased the number of synaptic connections in the hippocampal CA1 region and striatum; enhanced the expression of synaptophysin, phosphorylated synapsin I and postsynaptic density protein 95 (PSD95), elevated phosphorylated calcium/calmodulin-dependent protein kinase II (p-CaMKII) expression, and inhibited the overexpression and aggregation of α-synuclein in the hippocampus, striatum and cerebral cortex of aged mice.. TSG improved the memory and movement functions in aged mice through protecting synapses and inhibiting α-synuclein overexpression and aggregation in multiple brain regions. The results suggest that TSG may be beneficial to the treatment of ageing-related neurodegenerative diseases.

Topics: Aging; alpha-Synuclein; Animals; Avoidance Learning; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Cerebral Cortex; Corpus Striatum; Female; Glucosides; Hippocampus; Memory; Memory Disorders; Mice, Inbred C57BL; Motor Activity; Movement Disorders; Neuroprotective Agents; Nootropic Agents; Protein Aggregates; Stilbenes; Synapses; Treatment Outcome

Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by a progressive degeneration of the striatonigral, olivo-ponto-cerebellar, and autonomic systems. Glial cytoplasmic inclusions (GCIs) containing alpha-synuclein represent the hallmark of MSA and are recapitulated in mice expressing alpha-synuclein in oligodendrocytes. To assess if oligodendroglial expression of human wild-type alpha-synuclein in mice (proteolipid promoter, PLP-SYN) could be associated with age-related deficits, PLP-SYN and wild-type mice were assessed for motor function, brain morphometry, striatal levels of dopamine and metabolites, dopaminergic loss, and distribution of GCIs. PLP-SYN displayed age-related impairments on a beam-traversing task. MRI revealed a significantly smaller brain volume in PLP-SYN mice at 12 months, which further decreased at 18 months together with increased volume of ventricles and cortical atrophy. The distribution of GCIs was reminiscent of MSA with a high burden in the basal ganglia. Mild dopaminergic cell loss was associated with decreased dopamine turnover at 18 months. These data indicate that PLP-SYN mice may recapitulate some of the progressive features of MSA and deliver endpoints for the evaluation of therapeutic strategies.

Topics: Age Factors; alpha-Synuclein; Animals; Atrophy; Brain; Cell Death; Cerebral Ventricles; Corpus Striatum; Dopamine; Humans; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Motor Activity; Movement Disorders; Multiple System Atrophy; Neuroglia; Organ Size

Alpha-synuclein (SNCA) downregulation shows therapeutic potential for synucleinopathies, including Parkinson's disease (PD). Previously we showed that human (h)SNCA gene silencing using a short hairpin (sh)RNA in rat substantia nigra (SN) protects against a hSNCA-induced forelimb deficit, but not dopamine (DA) neuron loss. Furthermore, the shRNA increases cell death in vitro, but the same target sequence embedded in a microRNA30 transcript (mir30-hSNCA) does not.. Examine hSNCA gene silencing using mir30-hSNCA in vivo.. Rats were stereotaxically injected into one SN with adeno-associated virus serotype 2/8 (AAV)-hSNCA, AAV-hSNCA plus AAV-mir30-SNCA or AAV-hSNCA plus a control non-silencing mir30-embedded siRNA and DA neuron markers and associated behavior were examined.. AAV2/8-mediated SN hSNCA expression induces a forelimb deficit and tyrosine hydroxylase-immunoreactive (TH-IR) neuron loss. hSNCA gene silencing using mir30-hSNCA protects against this forelimb deficit at 2 m and ameliorates TH-IR neuron loss. Striatal (ST) TH-IR fiber density and DA markers, assessed by western blot, are unaffected by AAV-hSNCA alone. Co-expression of either silencing vector reduces ST TH-IR fibers, panTH in SN and Ser40 phosphorylated TH in SN and ST, but does not affect vesicular monoamine transporter-2. However, hSNCA gene silencing promotes partial TH-IR fiber recovery by 2 m. Co-expression of either silencing vector also induces SN inflammation, although some recovery was observed by 2 m in hSNCA-silenced SN.. hSNCA gene silencing with AAV-mir30-hSNCA has positive effects on forelimb behavior and SN DA neurons, which are compromised by inflammation and reduced TH expression, suggesting that AAV2/8-mir30-hSNCA-mediated gene silencing, although promising in vitro, is not a candidate for therapeutic translation for PD.

Topics: alpha-Synuclein; Animals; Corpus Striatum; Dependovirus; Dopamine; Forelimb; Gene Transfer Techniques; Genetic Vectors; Humans; Male; MicroRNAs; Motor Activity; Movement Disorders; Neurons; Rats; Rats, Sprague-Dawley; RNA Interference; RNA, Small Interfering; Substantia Nigra; Tyrosine 3-Monooxygenase; Vesicular Monoamine Transport Proteins

Cholesterol-oximes TRO19622 and TRO40303 target outer mitochondrial membrane proteins and have beneficial effects in preclinical models of neurodegenerative diseases leading to their advancement to clinical trials. Dopaminergic neurons degenerate in Parkinson's disease (PD) and are prone to oxidative stress and mitochondrial dysfunction. In order to provide insights into the neuroprotective potential of TRO19622 and TRO40303 for dopaminergic neurons in vivo, we assessed their effects on gene expression in laser captured nigrostriatal dopaminergic neurons of wildtype mice and of mice that over-express alpha-synuclein, a protein involved in both familial and sporadic forms of PD (Thy1-aSyn mice). Young mice were fed the drugs in food pellets or a control diet from 1 to 4months of age, approximately 10months before the appearance of striatal dopamine loss in this model. Unbiased weighted gene co-expression network analysis (WGCNA) of transcriptional changes revealed effects of cholesterol oximes on transcripts related to mitochondria, cytoprotection and anti-oxidant response in wild-type and transgenic mice, including increased transcription of stress defense (e.g. Prdx1, Prdx2, Glrx2, Hspa9, Pink1, Drp1, Trak1) and dopamine-related (Th, Ddc, Gch1, Dat, Vmat2, Drd2, Chnr6a) genes. Even at this young age transgenic mice showed alterations in transcripts implicated in mitochondrial function and oxidative stress (e.g. Bcl-2, Bax, Casp3, Nos2), and both drugs normalized about 20% of these alterations. Young Thy1-aSyn mice exhibit motor deficits that differ from parkinsonism and are established before the onset of treatment; these deficits were not improved by cholesterol oximes. However, high doses of TRO40303 improved olfaction and produced the same effects as dopamine agonists on a challenging beam test, specifically an increase in footslips, an observation congruent with its effects on transcripts involved in dopamine synthesis. High doses of TRO19622 increased alpha-synuclein aggregates in the substantia nigra; this effect, not seen with TRO40303 was inconsistent and may represent a protective mechanism as in other neurodegenerative diseases. Overall, the results suggest that cholesterol oximes, while not improving early effects of alpha-synuclein overexpression on motor behavior or pathology, may ameliorate the function and resilience of dopaminergic neurons in vivo and support further studies of neuroprotection in models with dopaminergic cell loss.

Topics: alpha-Synuclein; Animals; Brain; Cholestenones; Corpus Striatum; Dopamine Agonists; Dopaminergic Neurons; Gene Expression; Humans; Male; Mice, Transgenic; Movement Disorders; Neuroprotective Agents; Oximes; Parkinsonian Disorders; RNA, Messenger; Secosteroids; Substantia Nigra; Transcriptome

Alpha-synuclein (αS) misfolding is associated with Parkinson's disease (PD) but little is known about the mechanisms underlying αS toxicity. Increasing evidence suggests that defects in membrane transport play an important role in neuronal dysfunction. Here we demonstrate that the GTPase Rab8a interacts with αS in rodent brain. NMR spectroscopy reveals that the C-terminus of αS binds to the functionally important switch region as well as the C-terminal tail of Rab8a. In line with a direct Rab8a/αS interaction, Rab8a enhanced αS aggregation and reduced αS-induced cellular toxicity. In addition, Rab8 - the Drosophila ortholog of Rab8a - ameliorated αS-oligomer specific locomotor impairment and neuron loss in fruit flies. In support of the pathogenic relevance of the αS-Rab8a interaction, phosphorylation of αS at S129 enhanced binding to Rab8a, increased formation of insoluble αS aggregates and reduced cellular toxicity. Our study provides novel mechanistic insights into the interplay of the GTPase Rab8a and αS cytotoxicity, and underscores the therapeutic potential of targeting this interaction.

Topics: alpha-Synuclein; Animals; Animals, Genetically Modified; Brain; Cell Line, Tumor; Cell Survival; Drosophila melanogaster; Drosophila Proteins; Escherichia coli; GTP Phosphohydrolases; Humans; Mice; Models, Molecular; Movement Disorders; Mutation; Neurons; Phosphorylation; Protein Binding; rab GTP-Binding Proteins; Rats; Synaptosomes

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are common neurodegenerative disorders of the aging population, characterized by progressive and abnormal accumulation of α-synuclein (α-syn). Recent studies have shown that C-terminus (CT) truncation and propagation of α-syn play a role in the pathogenesis of PD/DLB. Therefore, we explored the effect of passive immunization against the CT of α-syn in the mThy1-α-syn transgenic (tg) mouse model, which resembles the striato-nigral and motor deficits of PD. Mice were immunized with the new monoclonal antibodies 1H7, 5C1, or 5D12, all directed against the CT of α-syn. CT α-syn antibodies attenuated synaptic and axonal pathology, reduced the accumulation of CT-truncated α-syn (CT-α-syn) in axons, rescued the loss of tyrosine hydroxylase fibers in striatum, and improved motor and memory deficits. Among them, 1H7 and 5C1 were most effective at decreasing levels of CT-α-syn and higher-molecular-weight aggregates. Furthermore, in vitro studies showed that preincubation of recombinant α-syn with 1H7 and 5C1 prevented CT cleavage of α-syn. In a cell-based system, CT antibodies reduced cell-to-cell propagation of full-length α-syn, but not of the CT-α-syn that lacked the 118-126 aa recognition site needed for antibody binding. Furthermore, the results obtained after lentiviral expression of α-syn suggest that antibodies might be blocking the extracellular truncation of α-syn by calpain-1. Together, these results demonstrate that antibodies against the CT of α-syn reduce levels of CT-truncated fragments of the protein and its propagation, thus ameliorating PD-like pathology and improving behavioral and motor functions in a mouse model of this disease.

Topics: alpha-Synuclein; Animals; Antibodies, Monoclonal; Brain; Disease Models, Animal; Humans; Immunotherapy; Mice; Mice, Transgenic; Movement Disorders; Parkinsonian Disorders; Tissue Distribution; Treatment Outcome

No disease-modifying therapies are available for synucleinopathies, including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple systems atrophy (MSA). The lack of therapies has been impeded by a paucity of validated drug targets and problematic cell-based model systems. New approaches are therefore needed to identify genes and compounds that directly target the underlying cellular pathologies elicited by the pathological protein, α-synuclein (α-syn). This small, lipid-binding protein impinges on evolutionarily conserved processes such as vesicle trafficking and mitochondrial function. For decades, the genetically tractable, single-cell eukaryote, budding yeast, has been used to study nearly all aspects of cell biology. More recently, yeast has revealed key insights into the underlying cellular pathologies caused by α-syn. The robust cellular toxicity caused by α-syn expression facilitates unbiased high-throughput small-molecule screening. Critically, one must validate the discoveries made in yeast in disease-relevant neuronal models. Here, we describe two recent reports that together establish yeast-to-human discovery platforms for synucleinopathies. In this exemplar, genes and small molecules identified in yeast were validated in patient-derived neurons that present the same cellular phenotypes initially discovered in yeast. On validation, we returned to yeast, where unparalleled genetic approaches facilitated the elucidation of a small molecule's mode of action. This approach enabled the identification and neuronal validation of a previously unknown "druggable" node that interfaces with the underlying, precipitating pathologies caused by α-syn. Such platforms can provide sorely needed leads and fresh ideas for disease-modifying therapy for these devastating diseases.

Topics: alpha-Synuclein; Animals; Humans; Movement Disorders; Neurons; Translational Research, Biomedical; Yeasts

Alpha-synuclein phosphorylated at serine 129 (S129) is highly elevated in Parkinson's disease patients where it mainly accumulates in the Lewy bodies. Several groups have studied the role of phosphorylation at the S129 in α-synuclein in a rat model for Parkinson's disease using recombinant adeno-associated viral (rAAV) vectors. The results obtained are inconsistent and accordingly the role of S129 phosphorylation in α-synuclein toxicity remains unclear. This prompted us to re-examine the neuropathological and behavioral effects of the S129 modified α-synuclein species in vivo. For this purpose, we used two mutated forms of human α-synuclein in which the S129 was replaced either with an alanine (S129A), to block phosphorylation, or with an aspartate (S129D), to mimic phosphorylation, and compared them with the wild type α-synuclein. This approach was similar in design to previous studies, however our investigation of dopaminergic degeneration also included performing a detailed study of the α-synuclein induced pathology in the striatum and the analysis of motor deficits. Our results showed that overexpressing S129D or wild type α-synuclein resulted in an accelerated dopaminergic fiber loss as compared with S129A α-synuclein. Furthermore, the motor deficit seen in the group treated with the mutant S129D α-synuclein appeared earlier than the other two forms of α-synuclein. Conversely, S129A α-synuclein showed significantly larger pathological α-synuclein-positive inclusions, and slower dopaminergic fiber loss, when compared to the other two forms of α-synuclein, suggesting a neuroprotective effect of the mutation. When examined at long-term, all three α-synuclein forms resulted in pathological accumulations of α-synuclein in striatal fibers and dopaminergic cell death in the substantia nigra. Our data show that changes in the S129 residue of α-synuclein influence the rate of pathology and neurodegeneration, with an overall deleterious effect of exchanging S129 to a residue mimicking its phosphorylated state.

Topics: alpha-Synuclein; Animals; Behavior, Animal; Blotting, Western; Corpus Striatum; Densitometry; Dependovirus; Dopamine; Female; Genetic Vectors; Immunohistochemistry; Movement Disorders; Mutation; Parkinson Disease; Phosphorylation; Rats; Rats, Sprague-Dawley; Serine; Transgenes

Compelling evidence suggests that accumulation and aggregation of alpha-synuclein (α-syn) contribute to the pathogenesis of Parkinson's disease (PD). Here, we describe a novel Bacterial Artificial Chromosome (BAC) transgenic model, in which we have expressed wild-type human α-syn fused to green fluorescent protein (GFP), under control of the mouse α-syn promoter. We observed a widespread and high expression of α-syn-GFP in multiple brain regions, including the dopaminergic neurons of the substantia nigra pars compacta (SNpc) and the ventral tegmental area, the olfactory bulb as well as in neocortical neurons. With increasing age, transgenic mice exhibited reductions in amphetamine-induced locomotor activity in the open field, impaired rotarod performance and a reduced striatal dopamine release, as measured by amperometry. In addition, they progressively developed deficits in an odor discrimination test. Western blot analysis revealed that α-syn-GFP and phospho-α-syn levels increased in multiple brain regions, as the mice grew older. Further, we observed, by immunohistochemical staining for phospho-α-syn and in vivo by two-photon microscopy, the formation of α-syn aggregates as the mice aged. The latter illustrates that the model can be used to track α-syn aggregation in vivo. In summary, this novel BAC α-syn-GFP model mimics a unique set of aspects of PD progression combined with the possibility of tracking α-syn aggregation in neocortex of living mice. Therefore, this α-syn-GFP-mouse model can provide a powerful tool that will facilitate the study of α-syn biology and its involvement in PD pathogenesis.

Topics: Aging; alpha-Synuclein; Amphetamine; Animals; Discrimination, Psychological; Dopamine; Dopamine Agents; Dopaminergic Neurons; Green Fluorescent Proteins; Humans; Locomotion; Mice; Mice, Transgenic; Movement Disorders; Neocortex; Nervous System Diseases; Olfaction Disorders; Smell; Substantia Nigra; Ventral Tegmental Area

Rapid eye movement sleep behavior disorder (RBD) is an early feature in α synucleinopathies and may precede other clinical manifestations of disease for several years. Olfactory dysfunction and mild motor abnormalities (MMAs) are highly prevalent in prodromal α synucleinopathies such as RBD and are suspected to be predictive neurodegenerative markers. Because both markers also are highly prevalent in the healthy elderly population, the discriminative value to detect an early neurodegenerative process is unclear.. We examined 28 patients with idiopathic RBD (iRBD) without manifest neurodegenerative disease to determine diagnostic accuracy of MMAs and olfactory dysfunction in identifying patients with early nigrostriatal degeneration in transcranial sonography (TCS) and (123)I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane single-photon emission computed tomography ((123)I-FP-CIT-SPECT).. Sixty-three percent of our participants showed MMAs which were strongly associated with abnormal TCS and (123)I-FP-CIT-SPECT findings. The discriminative value in detecting participants with early nigrostriatal degeneration was excellent (area under the receiver operating characteristic [ROC] curve, 0.84 [P≤.003] for TCS and 0.79 [P≤.066] for (123)I-FP-CIT-SPECT). Olfactory dysfunction was present in 78% of iRBD participants, but it was not linked with neuroimaging abnormalities or MMAs. Olfactory dysfunction did not discriminate participants with early nigrostriatal degeneration (area under the ROC curve, 0.54 [P≤.747] for TCS and 0.31 [P≤.225] for (123)I-FP-CIT-SPECT). Early RBD manifestation but no demographic (e.g., age, gender) or clinical characteristics of RBD (e.g., duration, severity of RBD) were associated with neuroimaging abnormalities in TCS and (123)I-FP-CIT-SPECT.. Unlike olfactory dysfunction, MMAs discriminate patients with early nigrostriatal degeneration in iRBD. Early RBD manifestation seems to be an additional risk factor which aggravates neurodegenerative risk.

Topics: Adult; Aged; Aged, 80 and over; alpha-Synuclein; Corpus Striatum; Early Diagnosis; Female; Humans; Male; Middle Aged; Movement Disorders; Neurodegenerative Diseases; Olfaction Disorders; Prevalence; REM Sleep Behavior Disorder; Risk Factors; Substantia Nigra; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Doppler, Transcranial

PARK4 is a candidate locus for familial Parkinson's disease (PD), combined with multiplication of the α-synuclein gene (SNCA). The eventual phenotype is dependent on the copy number of SNCA. Mutations in leucine-rich repeat kinase 2 (LRRK2) are also causative of parkinsonism. This report describes a man who presented at our hospital complaining of a stagger after running and difficulty in handling the mouse of a personal computer, having suffered tremors since his twenties. Nine months after treatment and discharge, he developed titubation and began to drag his right foot.. We examined the patient's family pedigree for SNCA dosage, using quantitative polymerase chain reaction. We also screened this pedigree for mutations in parkin and LRRK2, using gene-sequencing techniques.. We identified the proband, his sister, and his paternal uncle as carrying a duplication of SNCA. In addition, we found that the proband and his mother carried the G2385R variant of the LRRK2, a strong risk factor for PD in Asians and the rare V1450I variant, although only the proband showed symptoms of parkinsonism. No mutations were found in parkin.. The combination of SNCA gene duplication and LRRK2 G2385R variant may explain the early onset of disease in this patient.

Topics: Adult; alpha-Synuclein; Cerebellum; Cerebral Cortex; Family Health; Female; Gene Duplication; Genetic Testing; Head Movements; Humans; Magnetic Resonance Imaging; Male; Movement Disorders

The pathogenesis of Parkinson's disease is characterized by progressive degeneration of dopaminergic neurons in substantia nigra (SNpc). FLZ, a novel synthetic squamosamide derivative from a Chinese herb, has been shown to have neuroprotective effects in experimental Parkinson's disease (PD) models. However, it is still unclear whether FLZ protects against PD through regulating the function of dopaminergic system. In this study, we carried out a set of in vitro and in vivo experiments to address these questions. Oral administration of FLZ significantly improved motor dysfunction of mice challenged by MPTP. The beneficial effects of FLZ on motor behavior attributed to the elevation of dopamine level in striatum, tyrosine hydroxylase (TH)-positive cells, and TH activity in the middle brain of mouse. Mechanism study showed that treatment of FLZ increased the phosphorylation of activating protein kinase B (Akt) and mammalian target of rapamycin (mTOR). Using LY294002 to block phosphoinositide 3-kinases (PI3K)/Akt signaling pathway prevented the phosphorylation of mTOR and attenuated the neuroprotection of FLZ in MN9D cells challenged by MPP(+). In addition, FLZ reduced the expression of RTP801, an important protein in PD, in mice and cells intoxicated by MPTP/MPP(+). Taken together, these results revealed a novel role that FLZ elevated TH expression and activity in dopaminergic neuron through activation of Akt/mTOR survival pathway and inhibition of RTP801 in MPTP/MPP(+)-induced PD models. The data also provided evidence that FLZ had potent neuroprotecive effects and might become a new promising anti-PD drug.

Topics: Adaptor Proteins, Signal Transducing; alpha-Synuclein; Animals; Benzeneacetamides; Blotting, Western; Cell Line; Chromones; Corpus Striatum; DNA-Binding Proteins; Dopamine; Dopaminergic Neurons; Flow Cytometry; Immunohistochemistry; Immunoprecipitation; Male; Mice; Mice, Inbred C57BL; Morpholines; Movement Disorders; MPTP Poisoning; Neuroprotective Agents; Oncogene Protein v-akt; Phenols; Postural Balance; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases; Transcription Factors; Tyrosine 3-Monooxygenase

In neurodegenerative diseases, it remains unclear why certain brain regions are selectively vulnerable to protein aggregation. In transgenic mice expressing human A53T α-synuclein, the brainstem and spinal cord develop the most prominent α-synuclein inclusions which correlate with age-dependent motor dysfunction. Herein we present the novel finding that this selective aggregation is in part dependent on the inability of chaperone-mediated autophagy (CMA) to effectively degrade α-synuclein in these brain regions. Lysosomal assays revealed that CMA activity was significantly decreased in aggregation-prone regions compared to the remainder of the brain. Previously, CMA activity has been shown to be proportional to levels of the CMA receptor Lamp-2a. Using antibodies, brain tissue from Lamp-2a null mice, enzymatic deglycosylation, and mass spectrometry, we identified Lamp2a as a novel 72kDa glycoprotein in the mouse brain. Examination of Lamp-2a levels revealed differences in expression across brain regions. The brainstem and the spinal cord had a more than three-fold greater levels of Lamp-2a as compared to regions less vulnerable to aggregation and exhibited a selective upregulation of Lamp-2a during development of α-synuclein inclusions. Despite this dynamic response of Lamp-2a, the levels of substrates bound to the brain lysosomes as well as the rates of substrate uptake and degradation were not proportional to the levels of Lamp-2a. These regional differences in CMA activity and Lamp-2a expression were found in both non-transgenic mice as well as A53T α-syn mice. Therefore, these are inherent variations and not a transgene-specific effect. However, differences in CMA activity may render select brain regions vulnerable to homeostatic dysfunction in the presence of stressors such as overexpression of human A53T α-syn. Collectively, the data provide a potential mechanism to explain the dichotomy of vulnerability or resistance that underlies brain regions during aggregate formation in neurodegenerative disease.

Topics: alpha-Synuclein; Animals; Autophagy; Blotting, Western; Brain; Brain Chemistry; Brain Stem; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Inclusion Bodies; Lysosomal-Associated Membrane Protein 2; Lysosomes; Mice; Mice, Transgenic; Molecular Chaperones; Movement Disorders; Neurodegenerative Diseases; Polymerase Chain Reaction; RNA; Spinal Cord

Parkinson's disease (PD) is characterized pathologically by the formation of ubiquitin and α-synuclein (α-syn)-containing inclusions (Lewy bodies), dystrophic dopamine (DA) terminals, and degeneration of midbrain DA neurons. The precise molecular mechanisms underlying these pathological features remain elusive. Accumulating evidence has implicated dysfunctional autophagy, the cell self-digestion and neuroprotective pathway, as one of the pathogenic systems contributing to the development of idiopathic PD. Here we characterize autophagy-deficient mouse models and provide in vivo evidence for the potential role that impaired autophagy plays in pathogenesis associated with PD. Cell-specific deletion of essential autophagy gene Atg7 in midbrain DA neurons causes delayed neurodegeneration, accompanied by late-onset locomotor deficits. In contrast, Atg7-deficient DA neurons in the midbrain exhibit early dendritic and axonal dystrophy, reduced striatal dopamine content, and the formation of somatic and dendritic ubiquitinated inclusions in DA neurons. Furthermore, whole-brain-specific loss of Atg7 leads to presynaptic accumulation of α-syn and LRRK2 proteins, which are encoded by two autosomal dominantly inherited PD-related genes. Our results suggest that disrupted autophagy may be associated with enhanced levels of endogenous α-syn and LRRK2 proteins in vivo. Our findings implicate dysfunctional autophagy as one of the failing cellular mechanisms involved in the pathogenesis of idiopathic PD.

Topics: alpha-Synuclein; Animals; Autophagy; Autophagy-Related Protein 5; Autophagy-Related Protein 7; Brain; Cells, Cultured; Chromatography, High Pressure Liquid; Dendrites; Disease Models, Animal; Dopamine; Dopaminergic Neurons; Embryo, Mammalian; Ephrin-B1; Fibroblasts; Gene Expression Regulation; Inclusion Bodies; Intermediate Filament Proteins; Mice; Mice, Transgenic; Microtubule-Associated Proteins; Motor Activity; Movement Disorders; Nerve Degeneration; Nerve Tissue Proteins; Nestin; Presynaptic Terminals; Tyrosine 3-Monooxygenase; Ubiquitin

Recessive mutations in parkin are the most common cause of familial early-onset Parkinson's disease (PD). Recent studies suggest that certain parkin mutants may exert dominant toxic effects to cultured cells and such dominant toxicity can lead to progressive dopaminergic (DA) neuron degeneration in Drosophila. To explore whether mutant parkin could exert similar pathogenic effects to mammalian DA neurons in vivo, we developed a BAC (bacterial artificial chromosome) transgenic mouse model expressing a C-terminal truncated human mutant parkin (Parkin-Q311X) in DA neurons driven by a dopamine transporter promoter. Parkin-Q311X mice exhibit multiple late-onset and progressive hypokinetic motor deficits. Stereological analyses reveal that the mutant mice develop age-dependent DA neuron degeneration in substantia nigra accompanied by a significant loss of DA neuron terminals in the striatum. Neurochemical analyses reveal a significant reduction of the striatal dopamine level in mutant mice, which is significantly correlated with their hypokinetic motor deficits. Finally, mutant Parkin-Q311X mice, but not wild-type controls, exhibit age-dependent accumulation of proteinase K-resistant endogenous alpha-synuclein in substantia nigra and colocalized with 3-nitrotyrosine, a marker for oxidative protein damage. Hence, our study provides the first mammalian genetic evidence that dominant toxicity of a parkin mutant is sufficient to elicit age-dependent hypokinetic motor deficits and DA neuron loss in vivo, and uncovers a causal relationship between dominant parkin toxicity and progressive alpha-synuclein accumulation in DA neurons. Our study underscores the need to further explore the putative link between parkin dominant toxicity and PD.

Topics: Aging; alpha-Synuclein; Animals; Chromosomes, Artificial, Bacterial; Corpus Striatum; Disease Models, Animal; Dopamine; Endopeptidase K; Genetic Vectors; Humans; Mice; Mice, Transgenic; Movement Disorders; Mutation; Nerve Degeneration; Parkinson Disease; Protein Structure, Tertiary; Substantia Nigra; Transfection; Ubiquitin-Protein Ligases

The two current major staging systems in use for Lewy body disorders fail to classify up to 50% of subjects. Both systems do not allow for large numbers of subjects who have Lewy-type alpha-synucleinopathy (LTS) confined to the olfactory bulb or who pass through a limbic-predominant pathway that at least initially bypasses the brainstem. The results of the current study, based on examination of a standard set of ten brain regions from 417 subjects stained immunohistochemically for alpha-synuclein, suggest a new staging system that, in this study, allows for the classification of all subjects with Lewy body disorders. The autopsied subjects included elderly subjects with Parkinson's disease, dementia with Lewy bodies, incidental Lewy body disease and Alzheimer's disease with Lewy bodies, as well as comparison groups without Lewy bodies. All subjects were classifiable into one of the following stages: I. Olfactory Bulb Only; IIa Brainstem Predominant; IIb Limbic Predominant; III Brainstem and Limbic; IV Neocortical. Progression of subjects through these stages was accompanied by a generally stepwise worsening in terms of striatal tyrosine hydroxylase concentration, substantia nigra pigmented neuron loss score, Mini Mental State Examination score and score on the Unified Parkinson's Disease Rating Scale Part 3. Additionally, there were significant correlations between these measures and LTS density scores. It is suggested that the proposed staging system would improve on its predecessors by allowing classification of a much greater proportion of cases.

Topics: Aged; Aged, 80 and over; Aging; alpha-Synuclein; Alzheimer Disease; Apolipoproteins E; Brain; Cognition Disorders; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Lewy Body Disease; Male; Movement Disorders; Nerve Degeneration; Neurodegenerative Diseases; Parkinson Disease; Severity of Illness Index

Chronic neuroinflammation is implicated in Parkinson's disease (PD). Inflammation involves the activation of microglia and astrocytes that release high levels of prostaglandins. There is a profound gap in our understanding of how cyclooxygenases and their prostaglandin products redirect cellular events to promote PD neurodegeneration. The major prostaglandin in the mammalian brain is prostaglandin D2, which readily undergoes spontaneous dehydration to generate the bioactive cyclopentenone prostaglandins of the J2 series. These J2 prostaglandins are highly reactive and neurotoxic products of inflammation shown in cellular models to impair the ubiquitin/proteasome pathway and cause the accumulation of ubiquitinated proteins. PD is a disorder that exhibits accumulation of ubiquitinated proteins in neuronal inclusions (Lewy bodies). The role of J2 prostaglandins in promoting PD neurodegeneration has not been investigated under in vivo conditions.. We addressed the neurodegenerative and behavioral effects of the administration of prostaglandin J2 (PGJ2) simultaneously into the substantia nigra/striatum of adult male FVB mice by subchronic microinjections. One group received unilateral injections of DMSO (vehicle, n = 6) and three groups received PGJ2 [3.4 microg or 6.7 microg (n = 6 per group) or 16.7 microg (n = 5)] per injection. Immunohistochemical and behavioral analyses were applied to assess the effects of the subchronic PGJ2 microinfusions.. Immunohistochemical analysis demonstrated a PGJ2 dose-dependent significant and selective loss of dopaminergic neurons in the substantia nigra while the GABAergic neurons were spared. PGJ2 also triggered formation of aggregates immunoreactive for ubiquitin and alpha-synuclein in the spared dopaminergic neurons. Moreover, PGJ2 infusion caused a massive microglia and astrocyte activation that could initiate a deleterious cascade leading to self-sustained progressive neurodegeneration. The PGJ2-treated mice also exhibited locomotor and posture impairment.. Our studies establish the first model of inflammation in which administration of an endogenous highly reactive product of inflammation, PGJ2, recapitulates key aspects of PD. Our novel PGJ2-induced PD model strongly supports the view that localized and chronic production of highly reactive and neurotoxic prostaglandins, such as PGJ2, in the CNS could be an integral component of inflammation triggered by insults evoked by physical, chemical or microbial stimuli and thus establishes a link between neuroinflammation and PD neurodegeneration.

Topics: alpha-Synuclein; Animals; Cell Death; Disease Models, Animal; Dopamine; Dose-Response Relationship, Drug; Drug Administration Schedule; Encephalitis; Gliosis; Immunohistochemistry; Inclusion Bodies; Inflammation Mediators; Male; Mice; Microinjections; Movement Disorders; Nerve Degeneration; Neurons; Parkinsonian Disorders; Prostaglandin D2; Substantia Nigra

Synphilin-1 represents a cytoplasmic protein that interacts with alpha-synuclein and localizes close to synaptic vesicles. The interaction of synphilin-1 with several proteins involved in Parkinson's disease suggests that it might be involved in the pathogenesis of the disease. Nonetheless, the function of synphilin-1 remains unclear. In the present study, we generated transgenic mice expressing human synphilin-1 under the prion protein promoter. Synphilin-1 was widely expressed in neurons in the brain including the substantia nigra, where massive loss of dopamine neurons was not observed. In the transgenic mouse brain, synphilin-1 protein was polyubiquitinated, and partially insoluble. Although modified-SHIRPA revealed no significant difference in behavior and morphology, the reduced rotarod performance and step length were observed in transgenic mice as compared with non-transgenic littermates. Synphilin-1 might be involved in motor function, and its accumulation in the central nervous system can cause motor impairments.

Topics: alpha-Synuclein; Animals; Behavior, Animal; Brain; Carrier Proteins; Gene Expression Regulation; Humans; Mice; Mice, Inbred C57BL; Mice, Transgenic; Motor Activity; Movement Disorders; Nerve Tissue Proteins; Neurons; Reaction Time; Tyrosine 3-Monooxygenase

The clinical syndrome of pure akinesia has most often been associated with progressive supranuclear palsy (PSP) and is characterized by difficulty initiating gait and "freezing" during walking, writing and speaking. Similar syndromes have been described under the rubrics of primary progressive freezing gait and primary gait ignition failure. We investigated the specificity of the clinical syndrome of pure akinesia with gait freezing (PAGF) for PSP-tau pathology. Among 749 patients archived at the QSBB, only 7 fulfilled proposed diagnostic criteria of: gradual onset of freezing of gait or speech; absent limb rigidity and tremor; no sustained response to levodopa; and no dementia or ophthalmoplegia in the first 5 years of disease. In these cases detailed pathological examination was performed. PSP was the pathological diagnosis in six patients, and Parkinson's disease (PD) in the seventh. As defined, this syndrome had a positive predictive value of 86% for PSP-tau pathology. In the cases with PSP there were no additional features of coexistent vascular or PD and the median PSP-tau score was 3, reflecting relative mild tau load. The clinical syndrome of PAGF appears to have a high specificity for PSP-tau pathology. This relatively uncommon presentation of PSP-tau pathology has less severe tau accumulation than in the more common, "classic" PSP clinical phenotype: Richardson's disease.

Topics: Adult; Aged; alpha-Synuclein; Brain; Fatal Outcome; Female; Gait Disorders, Neurologic; Humans; Immunohistochemistry; Lewy Bodies; Male; Middle Aged; Movement Disorders; Phenotype; Retrospective Studies; Supranuclear Palsy, Progressive

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by parkinsonism unresponsive to dopaminergic therapy, cerebellar ataxia, and dysautonomia. Neuropathology shows a characteristic neuronal multisystem degeneration that is associated with widespread oligodendroglial alpha-synuclein (alpha-SYN) inclusions. Presently no animal model completely replicates the specific neuropathology of MSA. Here we investigated the behavioral and pathological features resulting from oligodendroglial alpha-SYN overexpression in transgenic mice exposed to mitochondrial inhibition by 3-nitropropionic acid. In transgenic mice 3-nitropropionic acid induced or augmented motor deficits that were associated with MSA-like pathology including striatonigral degeneration and olivopontocerebellar atrophy. Widespread astrogliosis and microglial activation were also observed in the presence of alpha-SYN in oligodendrocytes. Our results indicate that combined mitochondrial inhibition and overexpression of oligodendroglial alpha-SYN generates a novel model of MSA that may be useful for evaluating both pathogenesis and treatment strategies.

Topics: alpha-Synuclein; Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Astrocytes; Disease Models, Animal; Image Processing, Computer-Assisted; Immunohistochemistry; Mice; Mice, Transgenic; Microglia; Movement; Movement Disorders; Multiple System Atrophy; Nerve Tissue Proteins; Neurons; Nitro Compounds; Oligodendroglia; Oxidative Stress; Propionates; Synucleins; Time Factors

Mice overexpressing mutant alpha-synuclein develop a progressive loss of motor function associated with the accumulation of aggregated alpha-synuclein in neurons of the brainstem. Recent reports suggest that tau pathology might also be associated with Parkinson disease (PD) and aggregation of alpha-synuclein. We now report that mice overexpressing A30P alpha-synuclein develop abnormally phosphorylated tau in parallel with the accumulation of aggregated alpha-synuclein. Enhanced phosphorylation of tau occurs only in symptomatic mice that also harbor abundant aggregated alpha-synuclein. The increased phosphorylation of tau occurs at S396/404 and S202 as shown by immunoblotting and immunocytochemical studies with the antibodies PHF-1 and AT8. Neurons that accumulated alpha-synuclein occurred in the dorsal brainstem and did not show strong colocalization with neurons that showed abnormal tau phosphorylation, which largely occurred in the ventral brainstem. Aggregation of alpha-synuclein and phosphorylation of tau are associated with increased levels of phosphorylated c-jun kinase (JNK), which is a stress kinase known to phosphorylate tau protein. These results suggest that alpha-synuclein pathology can stimulate early pathological changes in tau.

Topics: Age Factors; Alanine; alpha-Synuclein; Amino Acid Substitution; Animals; Antibodies, Monoclonal; Blotting, Western; Brain; Disease Models, Animal; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; JNK Mitogen-Activated Protein Kinases; Male; MAP Kinase Kinase 4; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mitogen-Activated Protein Kinase Kinases; Movement Disorders; Mutation; Nerve Tissue Proteins; Neurons; Parkinson Disease; Phosphorylation; Proline; Synucleins; tau Proteins

Using a viral vector for mutant (P301L) tau, we studied the effects of gene transfer to the rat substantia nigra in terms of structural and functional properties of dopaminergic neurons. The mutant tau vector caused progressive loss of pars compacta dopaminergic neurons over time, reduced striatal dopamine content, and amphetamine-stimulated rotational behavior consistent with a specific lesion effect. In addition, structural studies demonstrated neurofibrillary tangles and neuritic pathology. Wild-type tau had similar effects on neuronal loss and rotational behavior. In contrast, mutant alpha-synuclein vectors did not induce rotational behavior, although alpha-synuclein filaments formed in nigrostriatal axons. Dopamine neuron function is affected by tau gene transfer and appears to be more susceptible to tau- rather than alpha-synuclein-related damage in this model. Both tau and alpha-synuclein are important for substantia nigra neurodegeneration models in rats, further indicating their potential as therapeutic targets for human diseases involving loss of dopamine neurons.

Topics: alpha-Synuclein; Animals; Behavior, Animal; Disease Models, Animal; Dopamine; Gene Transfer Techniques; Genetic Vectors; Male; Motor Activity; Movement Disorders; Mutation; Nerve Degeneration; Neurofibrillary Tangles; Rats; Rats, Sprague-Dawley; Rotation; Substantia Nigra; tau Proteins; Tauopathies

To clarify the significance of Lewy body (LB)-related alpha-synucleinopathy in aging and various neurodegenerative disorders, its incidence and topographic pattern were examined in 260 brains of elderly patients, including 116 autopsy-proven cases of Alzheimer disease (AD), 71 cases of clinically and autopsy-proven Parkinson disease (PD), 38 of dementia with Lewy bodies (DLB), 8 patients with progressive supranuclear palsy (PSP), one with senile tremor, and 26 age-matched controls without neuropsychiatric disorders. Using immunohistochemistry, alpha-synuclein (AS) positive lesions were assessed semiquantitatively. For technical reasons, the olfactory system was not systematically studied. All PD-brains showed AS-positive lesions in medullary, pontine and mesencephalic nuclei, with involvement of the nucleus basalis (90.1%), limbic cortex (58.9%), cingulate cortex (46%), amygdala, CA 2/3 hippocampal region (36.2%), neocortex (28.8%), and striatum (11%). 88% of clinical PD cases corresponded to LB pathology stages 4-6, 12% to stage 3 according to Braak et al. (2003). 84% of DLB brains were PD stage 5 or 6 and 17% stage 4, without significant differences between DLB with and without neuritic AD pathology, suggesting morphologic similarities betwee these disorders. 6/8 PSP and senile tremor cases, 49.1% of AD and 69% of aged controls were negative. AS-positive lesions in AD showed decreasing incidence from midbrain (24-28%), limbic cortex and amygdala (17-18%), nucleus basalis and medullary nuclei (13-17%), cingulate cortex (12%), CA 2/3 region (8%) to neocortex (2%), without gender differences or relationship to the severity of AD pathology (mean Braak stage 5.1). AD cases with AS positive lesions, particularly those with AS pathology in the amygdala, were older at death than negative ones (86.6 vs 83.3 yrs), but this difference was not statistically significant. 15 AD cases (seven of them with mild PD symptoms) and 3 aged controls without parkinsonian signs but LB pathology stages 3 (n=5) and 4 (n=13) were considered "incidental LB disease". 16 AD brains without parkinsonian symptoms had AS positive lesions in various areas without medullary involvement, suggesting deviation from the proposed stereotypic expansion pattern. Located AS-pathology in the midbrain and limbic cortex was seen in 31% of asymptomatic aged controls. These data 1. largely confirm Braak's staging of LB-pathology in PD; 2. suggest morphologic and pathogenic relations between PD (brainst

Topics: Aged; Aged, 80 and over; Aging; alpha-Synuclein; Alzheimer Disease; Autopsy; Brain; Cohort Studies; Female; Humans; Lewy Bodies; Lewy Body Disease; Male; Middle Aged; Movement Disorders; Nerve Tissue Proteins; Parkinson Disease; Reference Values; Retrospective Studies; Supranuclear Palsy, Progressive; Synucleins

The identification of pathogenic mutations in the three genes alpha-synuclein, parkin, and ubiquitin carboxy-terminal hydrolase L1 (UCHL1) has elucidated the ubiquitin proteasome system (UPS) and its potential role as a causal pathway in Parkinson's disease (PD). In addition, polymorphisms of these three genes have been shown to be independently associated with PD. In a sample of 298 unrelated PD cases and 185 controls, we applied a two-phased approach of recursive partitioning and logistic regression analyses to explore complex interactions. For women only, we observed an epistatic interaction of UCHL1 and alpha-synuclein genotypes with significant effects on PD risk (odds ratio = 2.42; P = 0.003). Our findings are consistent with the hypothesis that PD is a multigenic disorder of the UPS.

Topics: alpha-Synuclein; Case-Control Studies; DNA Restriction Enzymes; Female; Genetic Predisposition to Disease; Genotype; Humans; Ligases; Logistic Models; Male; Movement Disorders; Mutation; Nerve Tissue Proteins; Parkinson Disease; Polymerase Chain Reaction; Synucleins; Thiolester Hydrolases; Ubiquitin Thiolesterase; Ubiquitin-Protein Ligases

alpha-Synucleinopathies are neurodegenerative disorders that range pathologically from the demise of select groups of nuclei to pervasive degeneration throughout the neuraxis. Although mounting evidence suggests that alpha-synuclein lesions lead to neurodegeneration, this remains controversial. To explore this issue, we generated transgenic mice expressing wild-type and A53T human alpha-synuclein in CNS neurons. Mice expressing mutant, but not wild-type, alpha-synuclein developed a severe and complex motor impairment leading to paralysis and death. These animals developed age-dependent intracytoplasmic neuronal alpha-synuclein inclusions paralleling disease onset, and the alpha-synuclein inclusions recapitulated features of human counterparts. Moreover, immunoelectron microscopy revealed that the alpha-synuclein inclusions contained 10-16 nm wide fibrils similar to human pathological inclusions. These mice demonstrate that A53T alpha-synuclein leads to the formation of toxic filamentous alpha-synuclein neuronal inclusions that cause neurodegeneration.

Topics: alpha-Synuclein; Animals; Axons; Behavior, Animal; Brain; Disease Models, Animal; Female; Gene Expression Regulation; Humans; Inclusion Bodies; Male; Mice; Mice, Transgenic; Microscopy, Electron; Movement Disorders; Nerve Tissue Proteins; Neurodegenerative Diseases; Neurons; Phenotype; Recombinant Fusion Proteins; Solubility; Spinal Cord; Synucleins; Wallerian Degeneration

The presynaptic protein alpha-synuclein is a prime suspect for contributing to Lewy pathology and clinical aspects of diseases, including Parkinson's disease, dementia with Lewy bodies, and a Lewy body variant of Alzheimer's disease. alpha-Synuclein accumulates in Lewy bodies and Lewy neurites, and two missense mutations (A53T and A30P) in the alpha-synuclein gene are genetically linked to rare familial forms of Parkinson's disease. Under control of mouse Thy1 regulatory sequences, expression of A53T mutant human alpha-synuclein in the nervous system of transgenic mice generated animals with neuronal alpha-synucleinopathy, features strikingly similar to those observed in human brains with Lewy pathology, neuronal degeneration, and motor defects, despite a lack of transgene expression in dopaminergic neurons of the substantia nigra pars compacta. Neurons in brainstem and motor neurons appeared particularly vulnerable. Motor neuron pathology included axonal damage and denervation of neuromuscular junctions in several muscles examined, suggesting that alpha-synuclein interfered with a universal mechanism of synapse maintenance. Thy1 transgene expression of wild-type human alpha-synuclein resulted in similar pathological changes, thus supporting a central role for mutant and wild-type alpha-synuclein in familial and idiotypic forms of diseases with neuronal alpha-synucleinopathy and Lewy pathology. These mouse models provide a means to address fundamental aspects of alpha-synucleinopathy and test therapeutic strategies.

Topics: alpha-Synuclein; Animals; Central Nervous System; Gene Expression Regulation; Humans; Lewy Bodies; Mice; Mice, Transgenic; Motor Activity; Motor Neurons; Movement Disorders; Mutation; Nerve Degeneration; Nerve Tissue Proteins; Neurodegenerative Diseases; Psychomotor Performance; Synucleins