scholarly journals Ablation of RIP3 protects from dopaminergic neurodegeneration in experimental Parkinson’s disease

2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Pedro A. Dionísio ◽  
Sara R. Oliveira ◽  
Maria M. Gaspar ◽  
Maria J. Gama ◽  
Margarida Castro-Caldas ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Cultured Cells ◽  
Substantia Nigra Pars Compacta ◽  
Neuronal Cultures ◽  
Interacting Protein ◽  
Dopaminergic Neurodegeneration

Abstract Parkinson’s disease (PD) is driven by dopaminergic neurodegeneration in the substantia nigra pars compacta (SN) and striatum. Although apoptosis is considered the main neurodegenerative mechanism, other cell death pathways may be involved. In this regard, necroptosis is a regulated form of cell death dependent on receptor interacting protein 3 (RIP3), a protein also implicated in apoptosis and inflammation independently of its pro-necroptotic activity. Here, we explored the role of RIP3 genetic deletion in in vivo and in vitro PD models. Firstly, wild-type (Wt) and RIP3 knockout (RIP3ko) mice were injected intraperitoneally with MPTP (40 mg/kg, i.p.), and sacrificed after either 6 or 30 days. RIP3ko protected from dopaminergic neurodegeneration in the SN of MPTP-injected mice, but this effect was independent of necroptosis. In keeping with this, necrostatin-1s (10 mg/kg/day, i.p.) did not afford full neuroprotection. Moreover, MPTP led to DNA fragmentation, caspase-3 activation, lipid peroxidation and BAX expression in Wt mice, in the absence of caspase-8 cleavage, suggesting intrinsic apoptosis. This was mimicked in primary cortical neuronal cultures exposed to the active MPTP metabolite. RIP3 deficiency in cultured cells and in mouse brain abrogated all phenotypes. Curiously, astrogliosis was increased in the striatum of MPTP-injected Wt mice and further exacerbated in RIP3ko mice. This was accompanied by absence of microgliosis and reposition of glial cell line-derived neurotrophic factor (GDNF) levels in the striata of MPTP-injected RIP3ko mice when compared to MPTP-injected Wt mice, which in turn showed a massive GDNF decrease. RIP3ko primary mixed glial cultures also presented decreased expression of inflammation-related genes upon inflammatory stimulation. These findings hint at possible undescribed non-necroptotic roles for RIP3 in inflammation and MPTP-driven cell death, which can contribute to PD progression.

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).

scholarly journals Bcl-2-associated athanogene 5 (BAG5) regulates Parkin-dependent mitophagy and cell death

2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Mitchell L. De Snoo ◽  
Erik L. Friesen ◽  
Yu Tong Zhang ◽  
Rebecca Earnshaw ◽  
Geneviève Dorval ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Family Member ◽  
Mitochondrial Damage ◽  
Interacting Protein ◽  
Dopaminergic Neurodegeneration ◽  
Defective Clearance ◽  
Promote Cell Death

AbstractAs pathogenic Parkin mutations result in the defective clearance of damaged mitochondria, Parkin-dependent mitophagy is thought to be protective against the dopaminergic neurodegeneration observed in Parkinson’s disease. Recent studies, however, have demonstrated that Parkin can promote cell death in the context of severe mitochondrial damage by degrading the pro-survival Bcl-2 family member, Mcl-1. Therefore, Parkin may act as a ‘switch’ that can shift the balance between protective or pro-death pathways depending on the degree of mitochondrial damage. Here, we report that the Parkin interacting protein, Bcl-2-associated athanogene 5 (BAG5), impairs mitophagy by suppressing Parkin recruitment to damaged mitochondria and reducing the movement of damaged mitochondria into the lysosomes. BAG5 also enhanced Parkin-mediated Mcl-1 degradation and cell death following severe mitochondrial insult. These results suggest that BAG5 may regulate the bi-modal activity of Parkin, promoting cell death by suppressing Parkin-dependent mitophagy and enhancing Parkin-mediated Mcl-1 degradation.

scholarly journals Maackiain Ameliorates 6-Hydroxydopamine and SNCA Pathologies by Modulating the PINK1/Parkin Pathway in Models of Parkinson’s Disease in Caenorhabditis elegans and the SH-SY5Y Cell Line

2020 ◽  
Vol 21 (12) ◽  
pp. 4455
Author(s):  
Rong-Tzong Tsai ◽  
Chia-Wen Tsai ◽  
Shih-Ping Liu ◽  
Jia-Xin Gao ◽  
Yun-Hua Kuo ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Caenorhabditis Elegans ◽  
Cell Line ◽  
Ubiquitin Proteasome System ◽  
Substantia Nigra Pars Compacta ◽  
Neuron Damage ◽  
6 Hydroxydopamine

The movement disorder Parkinson’s disease (PD) is the second most frequently diagnosed neurodegenerative disease, and is associated with aging, the environment, and genetic factors. The intracellular aggregation of α-synuclein and the loss of dopaminergic neurons in the substantia nigra pars compacta are the pathological hallmark of PD. At present, there is no successful treatment for PD. Maackiain (MK) is a flavonoid extracted from dried roots of Sophora flavescens Aiton. MK has emerged as a novel agent for PD treatment that acts by inhibiting monoamine oxidase B. In this study, we assessed the neuroprotective potential of MK in Caenorhabditis elegans and investigated possible mechanism of this neuroprotection in the human SH-SY5Y cell line. We found that MK significantly reduced dopaminergic neuron damage in 6-hydroxydopamine (6-OHDA)-exposed worms of the BZ555 strain, with corresponding improvements in food-sensing behavior and life-span. In transgenic worms of strain NL5901 treated with 0.25 mM MK, the accumulation of α-synuclein was diminished by 27% (p < 0.01) compared with that in untreated worms. Moreover, in worms and the SH-SY5Y cell line, we confirmed that the mechanism of MK-mediated protection against PD pathology may include blocking apoptosis, enhancing the ubiquitin-proteasome system, and augmenting autophagy by increasing PINK1/parkin expression. The use of small interfering RNA to downregulate parkin expression in vivo and in vitro could reverse the benefits of MK in PD models. MK may have considerable therapeutic applications in PD.

Calcium Channels as a Potential Target for Neuroprotection in Parkinson’s Disease

US Neurology ◽  
2011 ◽  
Vol 07 (02) ◽  
pp. 109 ◽  
Author(s):  
Tanya Simuni ◽  
D James Surmeier ◽  
◽  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neuroprotective Effect ◽  
Selective Vulnerability ◽  
Phase Iii ◽  
Substantia Nigra Pars Compacta ◽  
Double Blind ◽  
Finding Study

Parkinson's disease (PD) is the second most common neurodegenerative disease affecting 1 % of the population above the age 65. The principal motor symptoms of PD are attributable to the preferential loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). Recent studies demonstrate that dopaminergic (DA) neurons in the SNc, as well as many neurons in other regions affected by PD, have a distinctive physiologic phenotype. They are autonomous L-type Cav1.3 Ca2+channels pacemakers. Continuous Ca2+influx results in increased oxidative stress that may explain the selective vulnerability of these neurons. More importantly for PD, blocking these channels with isradipine, the most potent of the dihydropyridine (DHP) channel antagonists at L-type Ca2+channels with the Cav1.3 subunit, protects these neurons inin vitroandin vivomodels of parkinsonism. Neuroprotective effect is achieved at the serum concentrations that can be achieved with the doses approved for human use. Recent epidemiologic data also points to a reduced risk of PD with chronic use of specifically centrally acting DHP Ca2+channel antagonists. Isradipine is an approved agent for the treatment of hypertension. Our pilot data demonstrate acceptable dose-dependent tolerability of isradipine in early PD. A pilot Phase II multicenter, double-blind, placebo-controlled, safety, tolerability, and dosage finding study of isradipine in early PD has completed recruitment, with the results of the study to be available in the near future. Results of that study will inform the design of the planned Phase III pivotal efficacy trial of isradipine, as a disease modifying agent in early PD.

Clioquinol Protects Against Cell Death in Parkinson’s Disease Models In Vivo and In Vitro

2009 ◽  
pp. 431-442 ◽  
Author(s):  
Simon Wilkins ◽  
Colin L. Masters ◽  
Ashley I. Bush ◽  
Robert A. Cherny ◽  
David I. Finkelstein
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Disease Models

PTX3 secreted by human adipose-derived stem cells promotes dopaminergic neuron repair in Parkinson's disease via inhibiting apoptosis

2021 ◽  
Author(s):  
Changlin Lian ◽  
Qiongzhen Huang ◽  
Xiangyang Zhong ◽  
Zhenyan He ◽  
Boyang Liu ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Stem Cells ◽  
Parkinson's Disease ◽  
Brain Slices ◽  
Human Mesenchymal Stem Cells ◽  
Substantia Nigra Pars Compacta ◽  
Therapeutic Effects ◽  
Label Free

Abstract Background Adipose-derived human mesenchymal stem cells (hADSCs) transplantation has recently emerged as a promising method in the treatment of Parkinson's disease (PD), however, the mechanism underlying has not been fully illustrated. Methods In this study, the therapeutic effects of the striatum stereotaxic injected hADSCs in 6-OHDA-induced mouse model were evaluated. Furthermore, an in vitro model of PD was constructed using tissue-organized brain slices. And the therapeutic effect was evaluated by co-culture of hADSCs and 6-OHDA-constructed brain slice. Within the analysis of hADSCs' exocrine proteins through RNA-seq, Human protein cytokine arrays and label-free quantitative proteomics, key extracellular factors were identified in hADSCs secretion environment.The degeneration of DA neurons and apoptosis were measured in PD samples in vivo and vitro models, and the beneficial effects were evaluated through quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot,Fluoro-Jade C, Tunel assay and immunofluorescence analysis. Results In this study, we discovered that hADSCs protected the dopaminergic (DA) neurons in vivo and vitro models.we identified Pentraxin3 (PTX3) as a key extracellular factor in hADSCs secretion environment. Moreover, we found that human recombinant Pentraxin3 (rhPTX3) treatment could rescue the physiological behaviour of the PD mice in-vivo, as well as prevent DA neurons from death and increase the neuronal terminals in the Ventral tegmental area (VTA) + substantia nigra pars compacta (SNc) and striatum (STR) on the PD brain slices in-vitro. Furthermore, within testing on the pro-apoptotic markers of PD mice brain following the treatment of rhPTX3, we found that rhPTX3 can prevent the apoptosis and the degeneration of DA neurons. Conclusions Overall, the current study investigated that PTX3, a hADSCs secreted protein, played a potential role in protecting the DA neurons from apoptosis and degeneration in PD progression as well as improving the motor performances in PD mice to give a possible mechanism of how hADSCs works in the cell replacement therapy in PD. Importantly, our study also provided potential translational implications for the development of PTX3-based therapeutics in PD.

scholarly journals Tetramethylpyrazine Analogue T-006 Exerts Neuroprotective Effects against 6-Hydroxydopamine-Induced Parkinson’s Disease In Vitro and In Vivo

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Hefeng Zhou ◽  
Min Shao ◽  
Xuanjun Yang ◽  
Chuwen Li ◽  
Guozhen Cui ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Coordination ◽  
Neurodegenerative Disorder ◽  
Nerve Fibers ◽  
Substantia Nigra Pars Compacta ◽  
Neuroprotective Effects ◽  
6 Hydroxydopamine

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc), and there is no cure for it at present. We have previously reported that the tetramethylpyrazine (TMP) derivative T-006 exhibited beneficial effects in Alzheimer’s disease (AD) models. However, its effect on PD remains unclear. In the present study, we investigated the neuroprotective effects and underlying mechanisms of T-006 against 6-hydroxydopamine- (6-OHDA-) induced lesions in in vivo and in vitro PD models. Our results demonstrated that T-006 alleviated mitochondrial membrane potential loss and restored the energy metabolism and mitochondrial biogenesis that were induced by 6-OHDA in PC12 cells. In addition, animal experiments showed that administration of T-006 significantly attenuated the 6-OHDA-induced loss of tyrosine hydroxylase- (TH-) positive neurons in the SNpc, as well as dopaminergic nerve fibers in the striatum, and also increased the concentration of dopamine and its metabolites (DOPAC, HVA) in the striatum. Functional deficits were restored following T-006 treatment in 6-OHDA-lesioned mice, as demonstrated by improved motor coordination and rotational behavior. In addition, we found that the neuroprotective effects of T-006 were mediated, at least in part, by the activation of both the PKA/Akt/GSK-3β and CREB/PGC-1α/NRF-1/TFAM pathways. In summary, our findings demonstrate that T-006 could be developed as a novel neuroprotective agent for PD, and the two pathways might be promising therapeutic targets for PD.

scholarly journals Enhanced Hexokinase 2 Expression and Lactate Production Promote The Apoptosis of Dopaminergic Neurons in Parkinson’s Disease

2021 ◽  
Author(s):  
Jingyi Li ◽  
Longmin Chen ◽  
Qixiong Qin ◽  
Danlei Wang ◽  
Jingwei Zhao ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Model ◽  
Dopaminergic Neurons ◽  
Lactate Production ◽  
Substantia Nigra Pars Compacta ◽  
Hexokinase 2 ◽  
Lactate Levels

Abstract Background: Parkinson’s disease (PD) is characterized by impaired mitochondrial function and decreased ATP levels. Glycolysis is upregulated and lactate production is enhanced in PD. Since lactate promotes apoptosis and α-synuclein accumulation in neurons, we hypothesized that the increased lactate resulted from upregulated glycolysis is involved in the apoptosis of dopaminergic neurons in PD.Methods: We examined the expression of hexokinase 2 (HK2) and lactate dehydrogenase (LDH), the key enzymes in glycolysis, and lactate levels in the substantia nigra pars compacta (SNpc) of MPTP-induced mouse model of PD and in MPP+-treated SH-SY5Y cells. We investigated the role of HK2, lactate and AMPK pathway in the apoptosis of dopaminergic neurons by intervened with 3-Brpa, the HK2 inhibitor, in in vivo and in vitro systems.Results: We found that the expression of HK2 and LDHA, and lactate levels were markedly increased in brain SNpc of MPTP-treated mouse and in MPP+-treated SH-SY5Y cells. Meanwhile, the apoptosis of dopaminergic neurons in the mouse model and the apoptosis of the SH-SY5Y in vitro system were increased. Intriguingly, using HK2 inhibitor or siRNA can decrease the lactate levels and suppressed the apoptosis of dopaminergic neurons both in vivo and in vitro. Mechanistically, lactate increased the activity of adenosine monophosphate activated protein kinase (AMPK), and suppressed the phosphorylation of serine/threonine kinase 1 (Akt) and mammalian target of rapamycin (mTOR). Conclusion：Inhibition of HK2 ameliorate the apoptosis of dopaminergic neurons through downregulating the lactate production and AMPK/ Akt/ mTOR pathway activation in PD.

scholarly journals Modeling Parkinson’s Disease Neuropathology and Symptoms by Intranigral Inoculation of Preformed Human α-Synuclein Oligomers

2020 ◽  
Vol 21 (22) ◽  
pp. 8535
Author(s):  
Laura Boi ◽  
Augusta Pisanu ◽  
Maria Francesca Palmas ◽  
Giuliana Fusco ◽  
Ezio Carboni ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Structural Properties ◽  
Substantia Nigra Pars Compacta ◽  
Current Evidence ◽  
Reactive Microglia ◽  
Neuronal Membranes ◽  
Cytokine Levels

The accumulation of aggregated α-synuclein (αSyn) is a hallmark of Parkinson’s disease (PD). Current evidence indicates that small soluble αSyn oligomers (αSynOs) are the most toxic species among the forms of αSyn aggregates, and that size and topological structural properties are crucial factors for αSynOs-mediated toxicity, involving the interaction with either neurons or glial cells. We previously characterized a human αSynO (H-αSynO) with specific structural properties promoting toxicity against neuronal membranes. Here, we tested the neurotoxic potential of these H-αSynOs in vivo, in relation to the neuropathological and symptomatic features of PD. The H-αSynOs were unilaterally infused into the rat substantia nigra pars compacta (SNpc). Phosphorylated αSyn (p129-αSyn), reactive microglia, and cytokine levels were measured at progressive time points. Additionally, a phagocytosis assay in vitro was performed after microglia pre-exposure to αsynOs. Dopaminergic loss, motor, and cognitive performances were assessed. H-αSynOs triggered p129-αSyn deposition in SNpc neurons and microglia and spread to the striatum. Early and persistent neuroinflammatory responses were induced in the SNpc. In vitro, H-αSynOs inhibited the phagocytic function of microglia. H-αsynOs-infused rats displayed early mitochondrial loss and abnormalities in SNpc neurons, followed by a gradual nigrostriatal dopaminergic loss, associated with motor and cognitive impairment. The intracerebral inoculation of structurally characterized H-αSynOs provides a model of progressive PD neuropathology in rats, which will be helpful for testing neuroprotective therapies.

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