scholarly journals Mercury is present in neurons and oligodendrocytes in regions of the brain affected by Parkinson’s disease and co-localises with Lewy bodies

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262464
Author(s):  
Roger Pamphlett ◽  
David P. Bishop
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Cortex ◽  
Substantia Nigra ◽  
Lewy Bodies ◽  
Locus Ceruleus ◽  
Mercury Exposure ◽  
Paraffin Sections ◽  
Icp Ms ◽  
The Brain

Objective Environmental toxicants are suspected to play a part in the pathogenesis of idiopathic Parkinson’s disease (PD) and may underlie its increasing incidence. Mercury exposure in humans is common and is increasing due to accelerating levels of atmospheric mercury, and mercury damages cells via oxidative stress, cell membrane damage, and autoimmunity, mechanisms suspected in the pathogenesis of PD. We therefore compared the cellular distribution of mercury in the tissues of people with and without PD who had evidence of previous mercury exposure by mercury being present in their locus ceruleus neurons. Materials and methods Paraffin sections from the brain and general organs of two people with PD, two people without PD with a history of mercury exposure, and ten people without PD or known mercury exposure, were stained for inorganic mercury using autometallography, combined with immunostaining for a-synuclein and glial cells. All had mercury-containing neurons in locus ceruleus neurons. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to confirm the presence of mercury and to look for other potentially toxic elements. Autometallography-stained locus ceruleus paraffin sections were examined to compare the frequency of previous mercury exposure between 20 PD and 40 non-PD individuals. Results In PD brains, autometallography-detected mercury was seen in neurons affected by the disease, such as those in the substantia nigra, motor cortex, striatum, thalamus, and cerebellum. Mercury was seen in oligodendrocytes in white and grey matter. Mercury often co-localised with Lewy bodies and neurites. A more restricted distribution of brain mercury was seen in people without PD (both with or without known mercury exposure), with no mercury present in the substantia nigra, striatum, or thalamus. The presence of autometallography-detected mercury in PD was confirmed with LA-ICP-MS, which demonstrated other potentially toxic metals in the locus ceruleus and high iron levels in white matter. Autometallography-detected mercury was found in locus ceruleus neurons in a similar proportion of PD (65%) and non-PD (63%) individuals. Conclusions In people with PD, mercury was found in neurons and oligodendrocytes in regions of the brain that are affected by the disease, and often co-localised with aggregated a-synuclein. Mercury in the motor cortex, thalamus and striatum could result in bradykinesia and rigidity, and mercury in the cerebellum could cause tremor. People without PD had a restricted uptake of mercury into the brain. The similar frequency of mercury in the locus ceruleus of people with and without PD suggests these two groups have had comparable previous mercury exposures but that PD brains have a greater predisposition to take up circulating mercury. While this post mortem study does not provide a direct link between mercury and idiopathic PD, it adds to the body of evidence that metal toxicants such as mercury play a role in the disease. A precautionary approach would be to reduce rising mercury levels in the atmosphere by limiting the burning of fossil fuels, which may be contributing to the increasing incidence of PD.

scholarly journals Neuroinflammation and protein pathology in Parkinson’s disease dementia

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Antonina Kouli ◽  
Marta Camacho ◽  
Kieren Allinson ◽  
Caroline H. Williams-Gray
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
T Lymphocytes ◽  
Substantia Nigra ◽  
Amyloid Β ◽  
Brain Regions ◽  
Parkinson’S Disease Dementia ◽  
Activated Microglia ◽  
Cell Counts ◽  
The Brain

AbstractParkinson’s disease dementia is neuropathologically characterized by aggregates of α-synuclein (Lewy bodies) in limbic and neocortical areas of the brain with additional involvement of Alzheimer’s disease-type pathology. Whilst immune activation is well-described in Parkinson’s disease (PD), how it links to protein aggregation and its role in PD dementia has not been explored. We hypothesized that neuroinflammatory processes are a critical contributor to the pathology of PDD. To address this hypothesis, we examined 7 brain regions at postmortem from 17 PD patients with no dementia (PDND), 11 patients with PD dementia (PDD), and 14 age and sex-matched neurologically healthy controls. Digital quantification after immunohistochemical staining showed a significant increase in the severity of α-synuclein pathology in the hippocampus, entorhinal and occipitotemporal cortex of PDD compared to PDND cases. In contrast, there was no difference in either tau or amyloid-β pathology between the groups in any of the examined regions. Importantly, we found an increase in activated microglia in the amygdala of demented PD brains compared to controls which correlated significantly with the extent of α-synuclein pathology in this region. Significant infiltration of CD4+ T lymphocytes into the brain parenchyma was commonly observed in PDND and PDD cases compared to controls, in both the substantia nigra and the amygdala. Amongst PDND/PDD cases, CD4+ T cell counts in the amygdala correlated with activated microglia, α-synuclein and tau pathology. Upregulation of the pro-inflammatory cytokine interleukin 1β was also evident in the substantia nigra as well as the frontal cortex in PDND/PDD versus controls with a concomitant upregulation in Toll-like receptor 4 (TLR4) in these regions, as well as the amygdala. The evidence presented in this study show an increased immune response in limbic and cortical brain regions, including increased microglial activation, infiltration of T lymphocytes, upregulation of pro-inflammatory cytokines and TLR gene expression, which has not been previously reported in the postmortem PDD brain.

Parkinson's Disease

2019 ◽  
pp. 252-273 ◽  
Author(s):  
Vaibhav Walia ◽  
Ashish Gakkhar ◽  
Munish Garg
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Older Patients ◽  
Neurodegenerative Disorder ◽  
Progressive Loss ◽  
The Brain

Parkinson's disease (PD) is a neurodegenerative disorder in which a progressive loss of the dopaminergic neurons occurs. The loss of the neurons is most prominent in the substantia nigra region of the brain. The prevalence of PD is much greater among the older patients suggesting the risk of PD increases with the increase of age. The exact cause of the neurodegeneration in PD is not known. In this chapter, the authors introduce PD, demonstrate its history, pathogenesis, neurobiology, sign and symptoms, diagnosis, and pharmacotherapy.

scholarly journals Targeting α-Synuclein for PD Therapeutics: A Pursuit on All Fronts

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 391 ◽  
Author(s):  
Margaux Teil ◽  
Marie-Laure Arotcarena ◽  
Emilie Faggiani ◽  
Florent Laferriere ◽  
Erwan Bezard ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Clinical Trials ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Lewy Bodies ◽  
Curative Treatment ◽  
Preclinical Studies ◽  
Cytoplasmic Inclusions ◽  
The Many ◽  
The Brain

Parkinson’s Disease (PD) is characterized both by the loss of dopaminergic neurons in the substantia nigra and the presence of cytoplasmic inclusions called Lewy Bodies. These Lewy Bodies contain the aggregated α-synuclein (α-syn) protein, which has been shown to be able to propagate from cell to cell and throughout different regions in the brain. Due to its central role in the pathology and the lack of a curative treatment for PD, an increasing number of studies have aimed at targeting this protein for therapeutics. Here, we reviewed and discussed the many different approaches that have been studied to inhibit α-syn accumulation via direct and indirect targeting. These analyses have led to the generation of multiple clinical trials that are either completed or currently active. These clinical trials and the current preclinical studies must still face obstacles ahead, but give hope of finding a therapy for PD with time.

scholarly journals Parkinson’s disease is a type of amyloidosis featuring accumulation of amyloid fibrils of α-synuclein

2019 ◽  
Vol 116 (36) ◽  
pp. 17963-17969 ◽  
Author(s):  
Katsuya Araki ◽  
Naoto Yagi ◽  
Koki Aoyama ◽  
Chi-Jing Choong ◽  
Hideki Hayakawa ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Amyloid Fibrils ◽  
Lewy Bodies ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Β Sheet ◽  
The Brain

Many neurodegenerative diseases are characterized by the accumulation of abnormal protein aggregates in the brain. In Parkinson’s disease (PD), α-synuclein (α-syn) forms such aggregates called Lewy bodies (LBs). Recently, it has been reported that aggregates of α-syn with a cross-β structure are capable of propagating within the brain in a prionlike manner. However, the presence of cross-β sheet-rich aggregates in LBs has not been experimentally demonstrated so far. Here, we examined LBs in thin sections of autopsy brains of patients with PD using microbeam X-ray diffraction (XRD) and found that some of them gave a diffraction pattern typical of a cross-β structure. This result confirms that LBs in the brain of PD patients contain amyloid fibrils with a cross-β structure and supports the validity of in vitro propagation experiments using artificially formed amyloid fibrils of α-syn. Notably, our finding supports the concept that PD is a type of amyloidosis, a disease featuring the accumulation of amyloid fibrils of α-syn.

scholarly journals Blood Plasma of Patients with Parkinson’s Disease Increases Alpha-Synuclein Aggregation and Neurotoxicity

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Peng Wang ◽  
Xin Li ◽  
Xuran Li ◽  
Weiwei Yang ◽  
Shun Yu
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Alternative Pathway ◽  
Lewy Bodies ◽  
Normal Subjects ◽  
Alpha Synuclein ◽  
Phosphatase 2A ◽  
Alpha Synuclein Aggregation ◽  
The Brain ◽  
Neighboring Neuron

A pathological hallmark of Parkinson’s disease (PD) is formation of Lewy bodies in neurons of the brain. This has been attributed to the spread of α-synuclein (α-syn) aggregates, which involves release of α-syn from a neuron and its reuptake by a neighboring neuron. We found that treatment with plasma from PD patients induced more α-syn phosphorylation and oligomerization than plasma from normal subjects (NS). Compared with NS plasma, PD plasma added to primary neuron cultures caused more cell death in the presence of extracellular α-syn. This was supported by the observations that phosphorylated α-syn oligomers entered neurons, rapidly increased accumulated thioflavin S-positive inclusions, and induced a series of metabolic changes that included activation of polo-like kinase 2, inhibition of glucocerebrosidase and protein phosphatase 2A, and reduction of ceramide levels, all of which have been shown to promote α-syn phosphorylation and aggregation. We also analyzed neurotoxicity of α-syn oligomers relative to plasma from different patients. Neurotoxicity was not related to age or gender of the patients. However, neurotoxicity was positively correlated with H&Y staging score. The modification in the plasma may promote spreading of α-syn aggregates via an alternative pathway and accelerate progression of PD.

scholarly journals It Is Time to Study Overlapping Molecular and Circuit Pathophysiologies in Alzheimer’s and Lewy Body Disease Spectra

2021 ◽  
Vol 15 ◽  
Author(s):  
Noritaka Wakasugi ◽  
Takashi Hanakawa
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Continuous Spectrum ◽  
Lewy Body ◽  
Lewy Bodies ◽  
Amyloid Β ◽  
Lewy Body Disease ◽  
Common Mechanism ◽  
Protein Accumulation ◽  
The Brain

Alzheimer’s disease (AD) is the leading cause of dementia due to neurodegeneration and is characterized by extracellular senile plaques composed of amyloid β1–42 (Aβ) as well as intracellular neurofibrillary tangles consisting of phosphorylated tau (p-tau). Dementia with Lewy bodies constitutes a continuous spectrum with Parkinson’s disease, collectively termed Lewy body disease (LBD). LBD is characterized by intracellular Lewy bodies containing α-synuclein (α-syn). The core clinical features of AD and LBD spectra are distinct, but the two spectra share common cognitive and behavioral symptoms. The accumulation of pathological proteins, which acquire pathogenicity through conformational changes, has long been investigated on a protein-by-protein basis. However, recent evidence suggests that interactions among these molecules may be critical to pathogenesis. For example, Aβ/tau promotes α-syn pathology, and α-syn modulates p-tau pathology. Furthermore, clinical evidence suggests that these interactions may explain the overlapping pathology between AD and LBD in molecular imaging and post-mortem studies. Additionally, a recent hypothesis points to a common mechanism of prion-like progression of these pathological proteins, via neural circuits, in both AD and LBD. This suggests a need for understanding connectomics and their alterations in AD and LBD from both pathological and functional perspectives. In AD, reduced connectivity in the default mode network is considered a hallmark of the disease. In LBD, previous studies have emphasized abnormalities in the basal ganglia and sensorimotor networks; however, these account for movement disorders only. Knowledge about network abnormalities common to AD and LBD is scarce because few previous neuroimaging studies investigated AD and LBD as a comprehensive cohort. In this paper, we review research on the distribution and interactions of pathological proteins in the brain in AD and LBD, after briefly summarizing their clinical and neuropsychological manifestations. We also describe the brain functional and connectivity changes following abnormal protein accumulation in AD and LBD. Finally, we argue for the necessity of neuroimaging studies that examine AD and LBD cases as a continuous spectrum especially from the proteinopathy and neurocircuitopathy viewpoints. The findings from such a unified AD and Parkinson’s disease (PD) cohort study should provide a new comprehensive perspective and key data for guiding disease modification therapies targeting the pathological proteins in AD and LBD.

scholarly journals MicroRNA‐124 and its target gene are altered in the substantia nigra (SNc) of the brain of MPTP‐mouse model of Parkinson's disease

2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
Nandhini Kanagaraj ◽  
S Thameem Dheen ◽  
Zhao Feng Peng ◽  
Dinesh Kumar Srinivasan ◽  
Samuel S W Tay
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Mouse Model ◽  
Target Gene ◽  
Microrna 124 ◽  
The Brain

scholarly journals Heterogeneity of Incipient Atrophy Patterns in Parkinson’s Disease

2018 ◽  
Author(s):  
Pedro D. Maia ◽  
Sneha Pandya ◽  
Justin Torok ◽  
Ajay Gupta ◽  
Yashar Zeighami ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Neurodegenerative Disorder ◽  
Neuronal Loss ◽  
High Variability ◽  
Clinical Value ◽  
Optimization Routine ◽  
Penalized Optimization ◽  
The Brain

AbstractParkinson’s Disease (PD) is a the second most common neurodegenerative disorder after Alzheimer’s disease and is characterized by cell death in the amygdala and in substructures of the basal ganglia such as the substantia nigra. Since neuronal loss in PD leads to measurable atrophy patterns in the brain, there is clinical value in understanding where exactly the pathology emerges in each patient and how incipient atrophy relates to the future spread of disease. A recent seed-inference algorithm combining an established network-diffusion model with an L1-penalized optimization routine led to new insights regarding the non-stereotypical origins of Alzheimer’s pathologies across individual subjects. Here, we leverage the same technique to PD patients, demonstrating that the high variability in their atrophy patterns also translates into heterogeneous seed locations. Our individualized seeds are significantly more predictive of future atrophy than a single seed placed at the substantia nigra or the amygdala. We also found a clear distinction in seeding patterns between two PD subgroups – one characterized by predominant involvement of brainstem and ventral nuclei, and the other by more widespread frontal and striatal cortices. This might be indicative of two distinct etiological mechanisms operative in PD. Ultimately, our methods demonstrate that the early stages of the disease may exhibit incipient atrophy patterns that are more complex and variable than generally appreciated.

scholarly journals Review of prodromal symptoms in Parkinson's Disease detected by MRI, EEG And microbiome

2019 ◽  
Author(s):  
Isabel Cristina Echeverri ◽  
Maria de la Iglesia Vayá ◽  
Jose Molina Mateo ◽  
Francia Restrepo de Mejia ◽  
Belarmino Segura Giraldo
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Magnetic Resonance ◽  
Substantia Nigra ◽  
Evidence Synthesis ◽  
Magnetic Resonance Images ◽  
Event Related Potential ◽  
Motor Symptoms ◽  
The Brain ◽  
Early Parkinson’S Disease

Context: Parkinson’s disease (PD) is catalogued as a disorder that causes motor symptoms; the evidence of literature shows the PD starts with non-motor signs, which can be detected in prodromal phases. These previous phases can be analyzed and studied through magnetic resonance images (MRI), electroencephalography (EEG) and microbiome.Objective: To systematically review the areas of the brain and brain-gut axis which affect in early Parkinson’s disease that can possibly be visualized and analyzed by MRI, EEG and the microbiome.Evidence acquisition: Pubmed and Embase databases were used until July 30, 2018 as to search for early Parkinson’s disease at its earliest non-motor symptoms stage by using MRI, EEG, and microbiome. The search was performed according to the requirements of a systematic review. In order to identify reports, we evaluated them following the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. Evidence synthesis: MRI and EEG have provided the advances to find features for PD over the last decade. Those techniques identify motor symptoms on substantia nigra where the patient shows a dopamine deficiency. However, over recent years, researchers have found that PD has prodromal phases, that is, PD is not simply a neurodegenerative disorder characterized by the dysfunction of dopaminergic. Thus, high field MRI, event-related potential (ERP) and microbiota data shows a significant change on the brain cortex, white and grey matter, the extrapyramidal system, brain signals and the gut.Conclusion: The structural MRI is a useful technique in detecting the stages of motor symptoms on the substantia nigra in patients with PD. The use of magnetic resonance as an early detector requires a high magnetic field, as to identify the areas which diagnose that the patient could be in the premotor stages. On the other hand, EEG performed well in detecting PD features. Furthermore, microbiome sequencing might include the classification of bacterial families that could help to detect PD in its prodromal phase. Thus, the combination of all these techniques can support the possibility of diagnosing PD in its very early stages.

scholarly journals Association Between Decreased Srpk3 Expression And An Increase In Substantia Nigra Alpha-Synuclein Levels In An MPTP-Induced Parkinson’s Disease Mouse Model

2022 ◽  
Author(s):  
Min Hyung Seo ◽  
Sujung Yeo
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Cell Loss ◽  
Alpha Synuclein ◽  
Mice Model ◽  
Dopaminergic Cell ◽  
The Brain

Abstract Parkinson’s disease (PD) is known as the second most common neurodegenerative disease, which is caused by destruction of dopaminergic neurons in the substantia nigra (SN) of the brain; however, the reason for the death of dopaminergic neurons remains unclear. An increase in α-synuclein (α-syn) is considered an important factor in the pathogenesis of PD. In the current study, we investigated the association between PD and serine/arginine-rich protein specific kinase 3 (Srpk3) in MPTP-induced parkinsonism mice model and in SH-SY5Y cells treated with MPP+. Srpk3 expression was significantly downregulated, while tyrosine hydroxylase (TH) decreased and α-synuclein (α-syn) increased after 4 weeks of MPTP intoxication treatment. Dopaminergic cell reduction and α-syn increase were demonstrated by inhibiting Srpk3 expression by siRNA in SH-SY5Y cells. Moreover, a decrease in Srpk3 expression upon siRNA treatment promoted dopaminergic cell reduction and α-syn increase in SH-SY5Y cells treated with MPP+. These results suggest that the decrease in Srpk3 expression due to Srpk3 siRNA caused both a decrease in TH and an increase in α-syn. This raises new possibilities for studying how Srpk3 controls dopaminergic cells and α-syn expression, which may be related to the pathogenesis of PD. Our results provide an avenue for understanding the role of Srpk3 during dopaminergic cell loss and α-syn increase in the SN. Furthermore, this study could support a therapeutic possibility for PD in that the maintenance of Srpk3 expression inhibited dopaminergic cell reduction.

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