scholarly journals Nano-imaging trace elements at organelle levels in substantia nigra overexpressing α-synuclein to model Parkinson’s disease

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Laurence Lemelle ◽  
Alexandre Simionovici ◽  
Philippe Colin ◽  
Graham Knott ◽  
Sylvain Bohic ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Trace Element ◽  
Brain Diseases ◽  
Transmission Electron ◽  
Rough Endoplasmic Reticula ◽  
Nano Imaging ◽  
Cellular Compartments ◽  
Endoplasmic Reticula

AbstractSub-cellular trace element quantifications of nano-heterogeneities in brain tissues offer unprecedented ways to explore at elemental level the interplay between cellular compartments in neurodegenerative pathologies. We designed a quasi-correlative method for analytical nanoimaging of the substantia nigra, based on transmission electron microscopy and synchrotron X-ray fluorescence. It combines ultrastructural identifications of cellular compartments and trace element nanoimaging near detection limits, for increased signal-to-noise ratios. Elemental composition of different organelles is compared to cytoplasmic and nuclear compartments in dopaminergic neurons of rat substantia nigra. They exhibit 150–460 ppm of Fe, with P/Zn/Fe-rich nucleoli in a P/S-depleted nuclear matrix and Ca-rich rough endoplasmic reticula. Cytoplasm analysis displays sub-micron Fe/S-rich granules, including lipofuscin. Following AAV-mediated overexpression of α-synuclein protein associated with Parkinson’s disease, these granules shift towards higher Fe concentrations. This effect advocates for metal (Fe) dyshomeostasis in discrete cytoplasmic regions, illustrating the use of this method to explore neuronal dysfunction in brain diseases.

scholarly journals Submicron Crystals of the Parkinson’s Disease Substantia nigra: Calcium Oxalate, Titanium Dioxide and Iron Oxide

2019 ◽  
Author(s):  
Adam Heller ◽  
Sheryl S. Coffman
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Calcium Oxalate ◽  
Nlrp3 Inflammasome ◽  
Dopaminergic Neurons ◽  
Number Density ◽  
Neuron Death ◽  
Transmission Electron ◽  
The Brain

AbstractParkinson’s disease (PD) results of the death of dopaminergic neurons of the substantia nigra. When activated, the NLRP3 inflammasome of phagocytes releases inflammatory agents, their release resulting in the death of proximal cells. The hallmark protein of PD, aggregated α-synuclein, is phagocytized and activates the NLRP3 inflammasome. Because crystalline particles are known to activate the NLRP3 inflammasome, to enhance α-synuclein expression and aggregation in dopaminergic neurons and because their facets may mis-template adsorbed α-synuclein, we probe here, by transmission electron microscopy (TEM), four human PD substantia nigra specimens for their crystalline particles. Samples weighing 5 mg of PD stages 1, 2, 4 and 5 were processed by proteolysis and centrifugation. TEM-grids were dipped in the centrifugate diluted to 1 mL and the dried films were searched for crystalline particles. Two types of crystalline particles, known to activate the NLRP3 inflammasome were found. Endogenous calcium oxalate, a downstream product of ascorbate and dopamine oxidation-produced hydrogen peroxide; and TiO2, the with pigment of foods and medications. The number-density of the NLRP-inflammasome activating crystalline particles found approached the reported about-equal number-densities of microglia and neuronal cells in the brain.The observations of COD and protein-coated TiO2 support two putative feedback loops, both leading to dopaminergic neuron death. In one, polymeric oxidized-dopamine catalyst accelerates H2O2-generation, the H2O2 indirectly oxidizing ascorbate in an ascorbate-fueled, oxalate-generating, loop the excess oxalate precipitating the subsequently inflammasome-activating COD crystals; In the second, protein-adsorbing facets of TiO2 mis-template the aggregation of α-synuclein to produce inflammasome-activating mis-folded α-synuclein.

Hyperechogenicity of substantia nigra in Parkinson's disease – Searching for genetic predictors

2008 ◽  
Vol 35 (S 01) ◽  
Author(s):  
C Funke ◽  
A Soehn ◽  
C Schulte ◽  
M Bonin ◽  
C Klein ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Genetic Predictors

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.

scholarly journals Assessment of the Telomere Length and Its Effect on the Symptomatology of Parkinson’s Disease

Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 137
Author(s):  
Tina Levstek ◽  
Sara Redenšek ◽  
Maja Trošt ◽  
Vita Dolžan ◽  
Katarina Trebušak Podkrajšek
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Telomere Length ◽  
Repetitive Sequences ◽  
Housekeeping Gene ◽  
Cellular Aging ◽  
Brain Diseases ◽  
Motor Complications ◽  
Telomere Attrition ◽  
Significant Difference

Telomeres, which are repetitive sequences that cap the end of the chromosomes, shorten with each cell division. Besides cellular aging, there are several other factors that influence telomere length (TL), in particular, oxidative stress and inflammation, which play an important role in the pathogenesis of neurodegenerative brain diseases including Parkinson’s disease (PD). So far, the majority of studies have not demonstrated a significant difference in TL between PD patients and healthy individuals. However, studies investigating the effect of TL on the symptomatology and disease progression of PD are scarce, and thus, warranted. We analyzed TL of peripheral blood cells in a sample of 204 PD patients without concomitant autoimmune diseases and analyzed its association with several PD related phenotypes. Monochrome multiplex quantitative PCR (mmqPCR) was used to determine relative TL given as a ratio of the amount of DNA between the telomere and albumin as the housekeeping gene. We found a significant difference in the relative TL between PD patients with and without dementia, where shorter TL presented higher risk for dementia (p = 0.024). However, the correlation was not significant after adjustment for clinical factors (p = 0.509). We found no correlations between TLs and the dose of dopaminergic therapy when the analysis was adjusted for genetic variability in inflammatory or oxidative factors. In addition, TL influenced time to onset of motor complications after levodopa treatment initiation (p = 0.0134), but the association did not remain significant after adjustment for age at inclusion and disease duration (p = 0.0781). Based on the results of our study we conclude that TL contributes to certain PD-related phenotypes, although it may not have a major role in directing the course of the disease. Nevertheless, this expends currently limited knowledge regarding the association of the telomere attrition and the disease severity or motor complications in Parkinson’s disease.

scholarly journals Therapeutic Potential of Magnetic Nanoparticle-Based Human Adipose-Derived Stem Cells in a Mouse Model of Parkinson’s Disease

2021 ◽  
Vol 22 (2) ◽  
pp. 654
Author(s):  
Ka Young Kim ◽  
Keun-A Chang
Keyword(s):  
Parkinson’S Disease ◽  
Stem Cells ◽  
Parkinson's Disease ◽  
Magnetic Nanoparticles ◽  
Substantia Nigra ◽  
Mouse Model ◽  
Magnetic Nanoparticle ◽  
Imaging System ◽  
Therapeutic Potential ◽  
Adipose Derived Stem Cells

Parkinson’s disease (PD) is a progressive neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra. Several treatments for PD have focused on the management of physical symptoms using dopaminergic agents. However, these treatments induce various adverse effects, including hallucinations and cognitive impairment, owing to non-targeted brain delivery, while alleviating motor symptoms. Furthermore, these therapies are not considered ultimate cures owing to limited brain self-repair and regeneration abilities. In the present study, we aimed to investigate the therapeutic potential of human adipose-derived stem cells (hASCs) using magnetic nanoparticles in a 6-hydroxydopamine (6-OHDA)-induced PD mouse model. We used the Maestro imaging system and magnetic resonance imaging (MRI) for in vivo tracking after transplantation of magnetic nanoparticle-loaded hASCs to the PD mouse model. The Maestro imaging system revealed strong hASCs signals in the brains of PD model mice. In particular, MRI revealed hASCs distribution in the substantia nigra of hASCs-injected PD mice. Behavioral evaluations, including apomorphine-induced rotation and rotarod performance, were significantly recovered in hASCs-injected 6-OHDA induced PD mice when compared with saline-treated counterparts. Herein, we investigated whether hASCs transplantation using magnetic nanoparticles recovered motor functions through targeted brain distribution in a 6-OHDA induced PD mice. These results indicate that magnetic nanoparticle-based hASCs transplantation could be a potential therapeutic strategy in PD.

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