scholarly journals DNAJB6 Suppresses Alpha-synuclein Induced Pathology in an Animal Model of Parkinson’s Disease

2020 ◽  
Author(s):  
Sertan Arkan ◽  
Mårten Ljungberg ◽  
Deniz Kirik ◽  
Christian Hansen
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Animal Model ◽  
Cell Death ◽  
Alpha Synuclein ◽  
Cellular Level ◽  
Substantia Nigra Pars Compacta ◽  
Motor Deficits ◽  
Dopaminergic Cell ◽  
Knock Out

Abstract Background: 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. Methods: we used to 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, phosphorylated α-syn in SNpc and axonal degeneration in striatum. Results : We show that DNAJB6 prevent α-syn aggregation induced by α-syn PFF’s, in a cell culture model. Also, we observed α-syn overexpression caused dopaminergic cell death and that this was strongly reduced by co-expression of DNAJB6b. In addition, 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. Moreover, we observed an increase in serine 129 (S129) phosphorylated α-syn in SNpc of rats overexpressing α-syn, that was lowered by DNAJB6 co-expression. Conclusion : 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. Keywords: Protein homeostasis, Parkinson`s Disease, Alpha-synuclein, Adeno Associated Virus, DNAJB6, Heat Shock Protein 70

scholarly journals Alpha-synuclein promotes dopaminergic neuron death in Parkinson’s disease through microglial and NLRP3 activation

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Sarah Klein
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nlrp3 Inflammasome ◽  
Neurodegenerative Disorder ◽  
Alpha Synuclein ◽  
Substantia Nigra Pars Compacta ◽  
Motor Deficits ◽  
Inflammasome Activation ◽  
Neuron Death ◽  
Nlrp3 Inflammasome Activation

Parkinson’s disease (PD) is a progressive neurodegenerative disorder that involves the death of dopaminergic neurons in the substantia nigra pars compacta (SNpc). After neuronal death, the subsequent reduction of dopamine levels in the brain induces motor deficits characteristic of this hypokinetic disorder. Although there is currently no known cause of PD, alpha-synuclein appears to have a prominent role in both microglial and NLRP3 inflammasome activation. The consequential release of the pro-inflammatory cytokine interleukin-1β (IL-1β) has been demonstrated to be responsible for neuroinflammation and neurodegeneration in PD. The present review highlights the role of alpha-synuclein aggregates in Parkinson’s disease pathogenesis. The PD alpha-synuclein preformed fibril (PFF) animal model permits the specific targeting of alpha-synuclein-mediated microglial and NLRP3 inflammasome activation in newly designed therapies. Studies using this model suggest MCC950 and its analogs as a potential new treatment to prevent neurodegeneration in Parkinson’s disease.

scholarly journals To be or not to be pink(1): contradictory findings in an animal model for Parkinson’s disease

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Ria de Haas ◽  
Lisa C M W Heltzel ◽  
Denise Tax ◽  
Petra van den Broek ◽  
Hilbert Steenbreker ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Animal Model ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
In Vivo Microdialysis ◽  
Substantia Nigra Pars Compacta ◽  
Laboratory Animals ◽  
Motor Deficits

Abstract The PTEN-induced putative kinase 1 knockout rat (Pink1−/−) is marketed as an established model for Parkinson’s disease, characterized by development of motor deficits and progressive degeneration of half the dopaminergic neurons in the substantia nigra pars compacta by 8 months of age. In this study, we address our concerns about the reproducibility of the Pink1−/− rat model. We evaluated behavioural function, number of substantia nigra dopaminergic neurons and extracellular striatal dopamine concentrations by in vivo microdialysis. Strikingly, we and others failed to observe any loss of dopaminergic neurons in 8-month-old male Pink1−/− rats. To understand this variability, we compared key experimental parameters from the different studies and provide explanations for contradictory findings. Although Pink1−/− rats developed behavioural deficits, these could not be attributed to nigrostriatal degeneration as there was no loss of dopaminergic neurons in the substantia nigra and no changes in neurotransmitter levels in the striatum. To maximize the benefit of Parkinson’s disease research and limit the unnecessary use of laboratory animals, it is essential that the research community is aware of the limits of this animal model. Additional research is needed to identify reasons for inconsistency between Pink1−/− rat colonies and why degeneration in the substantia nigra is not consistent.

scholarly journals Peripheral Inflammation Enhances Microglia Response and Nigral Dopaminergic Cell Death in an in vivo MPTP Model of Parkinson’s Disease

2018 ◽  
Vol 12 ◽  
Author(s):  
Irene García-Domínguez ◽  
Karolina Veselá ◽  
Juan García-Revilla ◽  
Alejandro Carrillo-Jiménez ◽  
María Angustias Roca-Ceballos ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Peripheral Inflammation ◽  
Dopaminergic Cell ◽  
Mptp Model

scholarly journals Elucidating the Neuroprotective Role of PPARs in Parkinson’s Disease: A Neoteric and Prospective Target

2021 ◽  
Vol 22 (18) ◽  
pp. 10161
Author(s):  
Tapan Behl ◽  
Piyush Madaan ◽  
Aayush Sehgal ◽  
Sukhbir Singh ◽  
Neelam Sharma ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Neurodegenerative Diseases ◽  
Hormone Receptors ◽  
Nerve Cells ◽  
Substantia Nigra Pars Compacta ◽  
Redox Equilibrium ◽  
Ppar Agonists

One of the utmost frequently emerging neurodegenerative diseases, Parkinson’s disease (PD) must be comprehended through the forfeit of dopamine (DA)-generating nerve cells in the substantia nigra pars compacta (SN-PC). The etiology and pathogenesis underlying the emergence of PD is still obscure. However, expanding corroboration encourages the involvement of genetic and environmental factors in the etiology of PD. The destruction of numerous cellular components, namely oxidative stress, ubiquitin-proteasome system (UPS) dysfunction, autophagy-lysosome system dysfunction, neuroinflammation and programmed cell death, and mitochondrial dysfunction partake in the pathogenesis of PD. Present-day pharmacotherapy can alleviate the manifestations, but no therapy has been demonstrated to cease disease progression. Peroxisome proliferator-activated receptors (PPARs) are ligand-directed transcription factors pertaining to the class of nuclear hormone receptors (NHR), and are implicated in the modulation of mitochondrial operation, inflammation, wound healing, redox equilibrium, and metabolism of blood sugar and lipids. Numerous PPAR agonists have been recognized to safeguard nerve cells from oxidative destruction, inflammation, and programmed cell death in PD and other neurodegenerative diseases. Additionally, various investigations suggest that regular administration of PPAR-activating non-steroidal anti-inflammatory drugs (NSAIDs) (ibuprofen, indomethacin), and leukotriene receptor antagonists (montelukast) were related to the de-escalated evolution of neurodegenerative diseases. The present review elucidates the emerging evidence enlightening the neuroprotective outcomes of PPAR agonists in in vivo and in vitro models experiencing PD. Existing articles up to the present were procured through PubMed, MEDLINE, etc., utilizing specific keywords spotlighted in this review. Furthermore, the authors aim to provide insight into the neuroprotective actions of PPAR agonists by outlining the pharmacological mechanism. As a conclusion, PPAR agonists exhibit neuroprotection through modulating the expression of a group of genes implicated in cellular survival pathways, and may be a propitious target in the therapy of incapacitating neurodegenerative diseases like PD.

scholarly journals Depopulation of α-synuclein aggregates is associated with rescue of dopamine neuron dysfunction and death in a new Parkinson’s disease model

2018 ◽  
Author(s):  
Michal Wegrzynowicz ◽  
Dana Bar-On ◽  
Laura Calo’ ◽  
Oleg Anichtchik ◽  
Mariangela Iovino ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Dopaminergic Neurons ◽  
Dopamine Release ◽  
Striatal Dopamine ◽  
Substantia Nigra Pars Compacta ◽  
Motor Deficit ◽  
Promising Therapeutic Approach ◽  
Striatal Dopamine Release

SUMMARYParkinson’s Disease (PD) is characterized by the presence of α-synuclein aggregates known as Lewy bodies and Lewy neurites, whose formation is linked to disease development. The causal relation between α-synuclein aggregates and PD is not well understood. We generated a new transgenic mouse line (MI2) expressing human, aggregation-prone truncated 1-120 α-synuclein under the control of the tyrosine hydroxylase promoter. MI2 mice exhibit progressive aggregation of α-synuclein in dopaminergic neurons of the substantia nigra pars compacta and their striatal terminals. This is associated with a progressive reduction of striatal dopamine release, reduced striatal innervation and significant nigral dopaminergic nerve cell death starting from 6 and 12 months of age, respectively. Overt impairment in motor behavior was found in MI2 mice at 20 months of age, when 50% of dopaminergic neurons are lost. These changes were associated with an increase in the number and density of 20-500nm α-synuclein species as shown by dSTORM. Treatment with the oligomer modulator anle138b, from 9-12 months of age, restored striatal dopamine release and prevented dopaminergic cell death. These effects were associated with a reduction of the inner density of α-synuclein aggregates and an increase in dispersed small α-synuclein species as revealed by dSTORM. The MI2 mouse model recapitulates the progressive dopaminergic deficit observed in PD, showing that early synaptic dysfunction precedes dopaminergic axonal loss and neuronal death that become associated with a motor deficit upon reaching a certain threshold. Our data also provide new mechanistic insight for the effect of anle138b’s function in vivo supporting that targeting α-synuclein aggregation is a promising therapeutic approach for PD.

scholarly journals Metabolomics Fingerprint Induced by the Intranigral Inoculation of Exogenous Human Alpha-Synuclein Oligomers in a Rat Model of Parkinson’s Disease

2020 ◽  
Vol 21 (18) ◽  
pp. 6745
Author(s):  
Federica Murgia ◽  
Luigi Atzori ◽  
Ezio Carboni ◽  
Maria Laura Santoru ◽  
Aran Hendren ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dehydroascorbic Acid ◽  
Alpha Synuclein ◽  
Mass Spectrometry Analysis ◽  
Substantia Nigra Pars Compacta ◽  
Gas Chromatography Mass Spectrometry ◽  
Serum Samples ◽  
Spectrometry Analysis ◽  
Metabolite Content

Parkinson’s disease (PD) is considered a synucleinopathy because of the intraneuronal accumulation of aggregated α-synuclein (αSyn). Recent evidence points to soluble αSyn-oligomers (αSynO) as the main cytotoxic species responsible for cell death. Given the pivotal role of αSyn in PD, αSyn-based models are crucial for the investigation of toxic mechanisms and the identification of new therapeutic targets in PD. By using a metabolomics approach, we evaluated the metabolic profile of brain and serum samples of rats infused unilaterally with preformed human αSynOs (HαSynOs), or vehicle, into the substantia nigra pars compacta (SNpc). Three months postinfusion, the striatum was dissected for striatal dopamine (DA) measurements via High Pressure Liquid Chromatography (HPLC) analysis and mesencephalon and serum samples were collected for the evaluation of metabolite content via gas chromatography mass spectrometry analysis. Multivariate, univariate and correlation statistics were applied. A 40% decrease of DA content was measured in the HαSynO-infused striatum as compared to the contralateral and the vehicle-infused striata. Decreased levels of dehydroascorbic acid, myo-inositol, and glycine, and increased levels of threonine, were found in the mesencephalon, while increased contents of fructose and mannose, and a decrease in glycine and urea, were found in the serum of HαSynO-infused rats. The significant correlation between DA and metabolite content indicated that metabolic variations reflected the nigrostriatal degeneration. Collectively, the metabolomic fingerprint of HαSynO-infused rats points to an increase of oxidative stress markers, in line with PD neuropathology, and provides hints for potential biomarkers of PD.

scholarly journals Neuroprotection in Parkinson’s disease: facts and hopes

2019 ◽  
Vol 127 (5) ◽  
pp. 821-829 ◽  
Author(s):  
András Salamon ◽  
Dénes Zádori ◽  
László Szpisjak ◽  
Péter Klivényi ◽  
László Vécsei
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Loss ◽  
Substantia Nigra Pars Compacta ◽  
Neuroprotective Agents ◽  
Dopaminergic Cell ◽  
Pathological Mechanism ◽  
Positive Results

AbstractParkinson’s disease (PD) is the second most common neurodegenerative disease worldwide. Behind the symptoms there is a complex pathological mechanism which leads to a dopaminergic cell loss in the substantia nigra pars compacta. Despite the strong efforts, curative treatment has not been found yet. To prevent a further cell death, numerous molecules were tested in terms of neuroprotection in preclinical (in vitro, in vivo) and in clinical studies as well. The aim of this review article is to summarize our knowledge about the extensively tested neuroprotective agents (Search period: 1991–2019). We detail the underlying pathological mechanism and summarize the most important results of the completed animal and clinical trials. Although many positive results have been reported in the literature, there is still no evidence that any of them should be used in clinical practice (Cochrane analysis was performed). Therefore, further studies are needed to better understand the pathomechanism of PD and to find the optimal neuroprotective agent(s).

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