Age-dependent elevations of oligomeric and phosphorylated alpha-synuclein synchronously occurs in the brain and gastrointestinal tract of cynomolgus monkeys

Abstract Synaptojanin1 (synj1) is a phosphoinositide phosphatase with dual SAC1 and 5′-phosphatase enzymatic activities in regulating phospholipid signaling. The brain-enriched isoform has been shown to participate in synaptic vesicle (SV) recycling. More recently, recessive human mutations were identified in the two phosphatase domains of SYNJ1, including R258Q, R459P and R839C, which are linked to rare forms of early-onset Parkinsonism. We now demonstrate that Synj1 heterozygous deletion (Synj1+/−), which is associated with an impaired 5′-phosphatase activity, also leads to Parkinson’s disease (PD)-like pathologies in mice. We report that male Synj1+/− mice display age-dependent motor function abnormalities as well as alpha-synuclein accumulation, impaired autophagy and dopaminergic terminal degeneration. Synj1+/− mice contain elevated 5′-phosphatase substrate, PI(4,5)P2, particularly in the midbrain neurons. Moreover, pharmacological elevation of membrane PI(4,5)P2 in cultured neurons impairs SV endocytosis, specifically in midbrain neurons, and further exacerbates SV trafficking defects in Synj1+/− midbrain neurons. We demonstrate down-regulation of SYNJ1 transcript in a subset of sporadic PD brains, implicating a potential role of Synj1 deficiency in the decline of dopaminergic function during aging.

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Preclinical Detection of Alpha-Synuclein Seeding Activity in the Colon of a Transgenic Mouse Model of Synucleinopathy by RT-QuIC

Viruses ◽

10.3390/v13050759 ◽

2021 ◽

Vol 13 (5) ◽

pp. 759

Author(s):

Jung-Youn Han ◽

Chaewon Shin ◽

Young Pyo Choi

Keyword(s):

Mouse Model ◽

Transgenic Mice ◽

Lewy Body ◽

Dementia With Lewy Body ◽

Transgenic Mouse Model ◽

Alpha Synuclein ◽

Gi Tract ◽

Colon Tissue ◽

Presymptomatic Stage ◽

The Brain

In synucleinopathies such as Parkinson’s disease (PD) and dementia with Lewy body (DLB), pathological alpha-synuclein (α-syn) aggregates are found in the gastrointestinal (GI) tract as well as in the brain. In this study, using real-time quaking-induced conversion (RT-QuIC), we investigated the presence of α-syn seeding activity in the brain and colon tissue of G2-3 transgenic mice expressing human A53T α-syn. Here we show that pathological α-syn aggregates with seeding activity were present in the colon of G2-3 mice as early as 3 months old, which is in the presymptomatic stage prior to the observation of any neurological abnormalities. In contrast, α-syn seeding activity was not detectable in 3 month-old mouse brains and only identified at 6 months of age in one of three mice. In the symptomatic stage of 12 months of age, RT-QuIC seeding activity was consistently detectable in both the brain and colon of G2-3 mice. Our results indicate that the RT-QuIC assay can presymptomatically detect pathological α-syn aggregates in the colon of G2-3 mice several months prior to their detection in brain tissue.

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The Peptide Vaccine Combined with Prior Immunization of a Conventional Diphtheria-Tetanus Toxoid Vaccine Induced AmyloidβBinding Antibodies on Cynomolgus Monkeys and Guinea Pigs

Journal of Immunology Research ◽

10.1155/2015/786501 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Akira Yano ◽

Kaori Ito ◽

Yoshikatsu Miwa ◽

Yoshito Kanazawa ◽

Akiko Chiba ◽

...

Keyword(s):

Immune Responses ◽

Tetanus Toxoid ◽

Guinea Pigs ◽

Peptide Vaccine ◽

Cell Epitope ◽

T Cell Epitope ◽

Peptide Vaccination ◽

Binding Profile ◽

Cynomolgus Monkeys ◽

The Brain

The reduction of brain amyloid beta (Aβ) peptides by anti-Aβantibodies is one of the possible therapies for Alzheimer’s disease. We previously reported that the Aβpeptide vaccine including the T-cell epitope of diphtheria-tetanus combined toxoid (DT) induced anti-Aβantibodies, and the prior immunization with conventional DT vaccine enhanced the immunogenicity of the peptide. Cynomolgus monkeys were given the peptide vaccine subcutaneously in combination with the prior DT vaccination. Vaccination with a similar regimen was also performed on guinea pigs. The peptide vaccine induced anti-Aβantibodies in cynomolgus monkeys and guinea pigs without chemical adjuvants, and excessive immune responses were not observed. Those antibodies could preferentially recognize Aβ40, and Aβ42compared to Aβfibrils. The levels of serum anti-Aβantibodies and plasma Aβpeptides increased in both animals and decreased the brain Aβ40level of guinea pigs. The peptide vaccine could induce a similar binding profile of anti-Aβantibodies in cynomolgus monkeys and guinea pigs. The peptide vaccination could be expected to reduce the brain Aβpeptides and their toxic effects via clearance of Aβpeptides by generated antibodies.

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The topography, structure and incidence of mineralized bodies in the basal ganglia of the brain of cynomolgus monkeys (Macaca fascicularis)

Laboratory Animals ◽

10.1258/002367795781088360 ◽

1995 ◽

Vol 29 (3) ◽

pp. 276-281 ◽

Cited By ~ 8

Author(s):

P. F. Wadsworth ◽

H. B. Jones ◽

J. B. Cavanagh

Keyword(s):

Basal Ganglia ◽

Natural Occurrence ◽

Optic Chiasma ◽

Cynomolgus Monkeys ◽

Small Vessels ◽

Mammillary Bodies ◽

Naturally Occurring ◽

Toxicological Studies ◽

One Year ◽

The Brain

Whole coronal slices from 6 levels of the brain of 16 cynomolgus monkeys (8 control and 8 treated by daily gavage with a novel pharmaceutical agent for one year) were examined histologically. Mineralized bodies were identified only in coronal sections passing through the optic chiasma and mammillary bodies. Identical mineralized structures were present in the basal ganglia of both control and treated animals. The majority were seen in the globus pallidus, occasionally in the putamen and once in the nearby caudate nucleus. These structures were partially ferruginated and also partially calcified. They appeared to arise in relation to small vessels. They are part of the naturally occurring background pathology of several species of non-human primates and the incidence in this study (3/8 control and 5/8 treated) was approximately what might be expected from reports in the literature. Mineralized bodies of the basal ganglia of primates represent a spontaneous lesion with a characteristic distribution. They may cause confusion in interpretation of toxicological studies if their natural occurrence is not appreciated.

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Deletion of murine tau gene increases tau aggregation in a human mutant tau transgenic mouse model

Biochemical Society Transactions ◽

10.1042/bst0381001 ◽

2010 ◽

Vol 38 (4) ◽

pp. 1001-1005 ◽

Cited By ~ 14

Author(s):

Kunie Ando ◽

Karelle Leroy ◽

Céline Heraud ◽

Anna Kabova ◽

Zehra Yilmaz ◽

...

Keyword(s):

Mouse Model ◽

Transgenic Mouse ◽

Double Mutant ◽

Transgenic Mouse Model ◽

Tau Proteins ◽

Dependent Manner ◽

Age Dependent ◽

Ad Alzheimer’S Disease ◽

Tau Aggregation ◽

The Brain

We have reported previously a tau transgenic mouse model (Tg30tau) overexpressing human 4R1N double-mutant tau (P301S and G272V) and that develops AD (Alzheimer's disease)-like NFTs (neurofibrillary tangles) in an age-dependent manner. Since murine tau might interfere with the toxic effects of human mutant tau, we set out to analyse the phenotype of our Tg30tau model in the absence of endogenous murine tau with the aim to reproduce more faithfully a model of human tauopathy. By crossing the Tg30tau line with TauKO (tau-knockout) mice, we have obtained a new mouse line called Tg30×TauKO that expresses only exogenous human double-mutant 4R1N tau. Whereas Tg30×TauKO mice express fewer tau proteins compared with Tg30tau, they exhibit augmented sarkosyl-insoluble tau in the brain and an increased number of Gallyas-positive NFTs in the hippocampus. Taken together, exclusion of murine tau causes accelerated tau aggregation during aging of this mutant tau transgenic model.

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Comparison of age‐dependent alterations in thioredoxin 2 and thioredoxin reductase 2 expressions in hippocampi between mice and rats

Laboratory Animal Research ◽

10.1186/s42826-021-00088-y ◽

2021 ◽

Vol 37 (1) ◽

Author(s):

Yeon Ho Yoo ◽

Dae Won Kim ◽

Bai Hui Chen ◽

Hyejin Sim ◽

Bora Kim ◽

...

Keyword(s):

Thioredoxin Reductase ◽

Pyramidal Cells ◽

Brain Regions ◽

Young Age ◽

Cresyl Violet ◽

Western Blots ◽

Protein Levels ◽

Cresyl Violet Staining ◽

Age Dependent ◽

The Brain

Abstract Background Aging is one of major causes triggering neurophysiological changes in many brain substructures, including the hippocampus, which has a major role in learning and memory. Thioredoxin (Trx) is a class of small redox proteins. Among the Trx family, Trx2 plays an important role in the regulation of mitochondrial membrane potential and is controlled by TrxR2. Hitherto, age-dependent alterations in Trx2 and TrxR2 in aged hippocampi have been poorly investigated. Therefore, the aim of this study was to examine changes in Trx2 and TrxR2 in mouse and rat hippocampi by age and to compare their differences between mice and rats. Results Trx2 and TrxR2 levels using Western blots in mice were the highest at young age and gradually reduced with time, showing that no significant differences in the levels were found between the two subfields. In rats, however, their expression levels were the lowest at young age and gradually increased with time. Nevertheless, there were no differences in cellular distribution and morphology in their hippocampi when it was observed by cresyl violet staining. In addition, both Trx2 and TrxR2 immunoreactivities in the CA1-3 fields were mainly shown in pyramidal cells (principal cells), showing that their immunoreactivities were altered like changes in their protein levels. Conclusions Our current findings suggest that Trx2 and TrxR2 expressions in the brain may be different according to brain regions, age and species. Therefore, further studies are needed to examine the reasons of the differences of Trx2 and TrxR2 expressions in the hippocampus between mice and rats.

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Alpha-synuclein alters the faecal viromes of rats in a gut-initiated model of Parkinson’s disease

10.1101/2021.03.29.437468 ◽

2021 ◽

Author(s):

S. R. Stockdale ◽

L. A. Draper ◽

S. M. O’Donovan ◽

W. Barton ◽

O. O’Sullivan ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Nervous System ◽

Lewy Body ◽

Neurological Disorder ◽

Alpha Synuclein ◽

Observational Period ◽

Β Diversity ◽

Potential Trigger ◽

The Brain

AbstractParkinson’s disease (PD) is a chronic neurological disorder associated with the misfolding of alpha-synuclein (α-syn) into Lewy body aggregates within nerve cells that contribute to their neurodegeneration. Recent evidence suggests α-syn aggregation may begin in the gut and travel to the brain along the vagus nerve, with microbes a potential trigger initiating the misfolding of α-syn. However, changes in the gut virome in response to α-syn alterations have not been investigated. In this study, we show longitudinal changes in the faecal virome of rats administered either monomeric or preformed fibrils (PFF) of α-syn directly into their enteric nervous system. Differential changes in rat viromes were observed when comparing monomeric and PFF α-syn. The virome β-diversity changes after α-syn treatment were compounded by the addition of LPS as an adjunct. Changes in the diversity of rat faecal viromes were observed after one month and did not resolve within the study’s five month observational period. Overall, these results suggest that microbiome alterations associated with PD may, partially, be reactive to host α-syn associated changes.

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Insights into the multifaceted role of circular RNAs: implications for Parkinson’s disease pathogenesis and diagnosis

npj Parkinson s Disease ◽

10.1038/s41531-021-00265-9 ◽

2022 ◽

Vol 8 (1) ◽

Author(s):

Epaminondas Doxakis

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Rna Binding ◽

Rna Binding Proteins ◽

Clinical Manifestations ◽

Alpha Synuclein ◽

Circular Rnas ◽

Age Related ◽

And Function ◽

The Brain

AbstractParkinson’s disease (PD) is a complex, age-related, neurodegenerative disease whose etiology, pathology, and clinical manifestations remain incompletely understood. As a result, care focuses primarily on symptoms relief. Circular RNAs (circRNAs) are a large class of mostly noncoding RNAs that accumulate with aging in the brain and are increasingly shown to regulate all aspects of neuronal and glial development and function. They are generated by the spliceosome through the backsplicing of linear RNA. Although their biological role remains largely unknown, they have been shown to regulate transcription and splicing, act as decoys for microRNAs and RNA binding proteins, used as templates for translation, and serve as scaffolding platforms for signaling components. Considering that they are stable, diverse, and detectable in easily accessible biofluids, they are deemed promising biomarkers for diagnosing diseases. CircRNAs are differentially expressed in the brain of patients with PD, and growing evidence suggests that they regulate PD pathogenetic processes. Here, the biogenesis, expression, degradation, and detection of circRNAs, as well as their proposed functions, are reviewed. Thereafter, research linking circRNAs to PD-related processes, including aging, alpha-synuclein dysregulation, neuroinflammation, and oxidative stress is highlighted, followed by recent evidence for their use as prognostic and diagnostic biomarkers for PD.

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