scholarly journals PD-1 Knockout Aggravates Motor Dysfunction In The MPTP Model of Parkinson's Disease By Inducing Microglial Activation And Neuroinflammation In Mice

Author(s):  
Ying-Ying Cheng ◽  
Bei-Yu Chen ◽  
Gan-Lan Bian ◽  
Yin-Xiu Ding ◽  
Liang-Wei CHEN

Abstract Background: Abundant microglial reaction and neuroinflammation are typical pathogenetic hallmark of brains in Parkinson’s disease (PD) patients, but regulation mechanisms are poorly understood. In this study, the promoting effects of PD-1-difficiency on microglial activation, neuroinflammation and motor dysfunction were identified using PD animal model.Methods: Using C57 wild-type (WT), PD-1 knockout (KO) and MPTP model, we designed WT-control, KO-control, WT-MPTP and KO-MPTP groups. Motor dysfunction of animal, distribution of PD-1-positive cells, dopaminergic neuronal survival, glial cell activation and generation of inflammatory cytokines in midbrains were observed by behavior detection, immunohistochemistry and western blot methods. Results: Microglial cells showing PD-1/Iba1 double-positivity were numerously distributed in the substantia nigra of control whereas they decreased in MPTP model. Compared with WT-MPTP, KO-MPTP mice exacerbated in their motor dysfunction, decreased level of TH expression and decreased TH-positive neuronal protrusions. Microglial cell activation and expression of proinflammatory cytokine iNOS, TNF-α, IL-1β and IL-6 significantly increased, and levels and phosphorylation of AKT and ERK1/2 were also elevated in KO-MPTP mice. Conclusions: PD-1 knockout could aggravate motor dysfunction of MPTP mouse model by promoting microglial activation and neuroinflammation in midbrains, suggesting that PD-1 signaling abnormality might be involved in PD pathogenesis or progression.

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1855
Author(s):  
Seulah Lee ◽  
Yeon Ji Suh ◽  
Yujeong Lee ◽  
Seonguk Yang ◽  
Dong Geun Hong ◽  
...  

Parkinson’s disease (PD) is one of the most common neurodegenerative disorders, and is caused by the death of dopamine neurons and neuroinflammation in the striatum and substantia nigra. Furthermore, the inflammatory response in PD is closely related to glial cell activation. This study examined the neuroprotective effects of the barbiturate derivative, MHY2699 [5-(4-hydroxy 3,5-dimethoxybenzyl)-2 thioxodihydropyrimidine-4,6(1H,5H)-dione] in a mouse model of PD. MHY2699 ameliorated MPP⁺-induced astrocyte activation and ROS production in primary astrocytes and inhibited the MPP⁺-induced phosphorylation of MAPK and NF-κB. The anti-inflammatory effects of MHY2699 in protecting neurons were examined in an MPTP-induced mouse model of PD. MHY2699 inhibited MPTP-induced motor dysfunction and prevented dopaminergic neuronal death, suggesting that it attenuated neuroinflammation. Overall, MHY2699 has potential as a neuroprotective treatment for PD.


2020 ◽  
Author(s):  
Angela A Tran ◽  
Myra De Smet ◽  
Gary D. Grant ◽  
Tien K. Khoo ◽  
Dean L Pountney

Major depressive disorder (MDD) affects more than cognition, having a temporal relationship with neuroinflammatory pathways of Parkinson’s disease (PD). Although this association is supported by epidemiological and clinical studies, the underlying mechanisms are unclear. Microglia and astrocytes play crucial roles in the pathophysiology of both MDD and PD. In PD, these cells can be activated by misfolded forms of the protein α-synuclein to release cytokines that can interact with multiple different physiological processes to produce depressive symptoms, including monoamine transport and availability, the hypothalamus-pituitary axis, and neurogenesis. In MDD, glial cell activation can be induced by peripheral inflammatory agents that cross the blood brain barrier and/or c-Fos signaling from neurons. The resulting neuroinflammation can cause neurodegeneration due to oxidative stress and glutamate excitotoxicity, contributing to PD pathology. Astrocytes are another major link due to their recognised role in the glymphatic clearance mechanism. Research suggesting that MDD causes astrocytic destruction or structural atrophy highlight the possibility that accumulation of α-synuclein in the brain is facilitated as the brain cannot adequately clear the protein aggregates. This review examines research into the overlapping pathophysiology of MDD and PD with particular focus on the roles of glial cells and neuroinflammation.


2021 ◽  
Author(s):  
Min-Ho Nam ◽  
Jong-Hyun Park ◽  
Hyo Jung Song ◽  
Ji Won Choi ◽  
Siwon Kim ◽  
...  

AbstractMonoamine oxidase-B (MAO-B) is a well-established therapeutic target for Parkinson’s disease (PD); however, previous clinical studies on currently available irreversible MAO-B inhibitors have yielded disappointing neuroprotective effects. Here, we tested the therapeutic potential of KDS2010, a recently synthesized potent, selective, and reversible MAO-B inhibitor in multiple animal models of PD. We designed and synthesized a series of α-aminoamide derivatives and found that derivative KDS2010 exhibited the highest potency, specificity, reversibility, and bioavailability (> 100%). In addition, KDS2010 demonstrated significant neuroprotective and anti-neuroinflammatory efficacy against nigrostriatal pathway destruction in the mouse MPTP model of parkinsonism. Treatment with KDS2010 also alleviated parkinsonian motor dysfunction in 6-hydroxydopamine-induced and A53T mutant α-synuclein overexpression rat models of PD. Moreover, KDS2010 showed virtually no toxicity or side effects in non-human primates. KDS2010 could be a next-generation therapeutic candidate for PD.


2021 ◽  
Author(s):  
Ying-Ying Cheng ◽  
Bei-Yu Chen ◽  
Gan-Lan Bian ◽  
Yin-Xiu Ding ◽  
Liang-Wei Chen

Abstract Abundant reactive gliosis and neuroinflammation are typical pathogenetic hallmarks of brains in Parkinson’s disease (PD) patients, but regulation mechanisms are poorly understood. We are interested in role of programmed death-1 (PD-1) in glial reaction, neuroinflammation and neuronal injury in PD pathogenesis. Using PD mouse model and PD-1 knockout (KO) mice, we designed wild-type-control (WT-CON), WT-1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (WT-MPTP), PD-1-KO-control (KO-CON) and PD-1-KO-MPTP (KO-MPTP), and observed motor dysfunction of animal, morphological distribution of PD-1-positive cells, dopaminergic neuronal injury, glial activation and generation of inflammatory cytokines in midbrains by motor behavior detection, immunohistochemistry and western blot. WT-MPTP mouse model exhibited decrease of PD-1/Iba1-positive microglial cells in the substantia nigra compared with WT-CON mice. By comparison of four groups, PD-1 deficiency showed exacerbation in motor dysfunction of animals, decreased expression of TH protein and TH-positive neuronal protrusions. PD-1 deficiency enhanced microglial activation, production of pro-inflammatory cytokines like inducible nitric oxide synthase, tumor necrosis factor-α, interleukin-1β and interleukin-6, and expression and phosphorylation of AKT and ERK1/2 in the substantia nigra of MPTP model. We concluded that PD-1 deficiency could aggravate motor dysfunction of MPTP mouse model by inducing microglial activation and neuroinflammation in midbrains, suggesting that PD-1 signaling abnormality might be possibly involved in PD pathogenesis.


2020 ◽  
Vol 23 (11) ◽  
pp. 762-773
Author(s):  
Wenjuan Rui ◽  
Sheng Li ◽  
Hong Xiao ◽  
Ming Xiao ◽  
Jingping Shi

Abstract Background Inflammasome-induced neuroinflammation is a major pathogenic mechanism underlying the degeneration of nigral dopaminergic neurons in Parkinson’s disease (PD). Baicalein is a flavonoid isolated from the traditional Chinese medicinal herbal Scutellaria baicalensis Georgi with known anti-inflammatory and neuroprotective efficacy in models of neurodegenerative diseases, including PD. However, its effects on inflammasome-induced neuroinflammation during PD remain unclear. Methods We used N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to induce PD-like pathology in mice. Behavioral assessments including the pole test, rotarod test, and open field test were conducted to evaluate the effects of baicalein on MPTP-induced motor dysfunction. The efficacies of baicalein against MPTP-induced dopaminergic neuron loss and glial cell activation in the substantia nigra compact were examined by immunohistochemistry, effects on proinflammatory cytokines by quantitative real-time PCR and enzyme-linked immunosorbent assay, and effects on inflammasome pathway activation by immunoblotting and flow cytometry. Results Administration of baicalein reversed MPTP-induced motor dysfunction, loss of dopaminergic neurons, and pro-inflammatory cytokine elevation. Baicalein also inhibited NLRP3 and caspase-1 activation and suppressed gasdermin D-dependent pyroptosis. Additionally, baicalein inhibited the activation and proliferation of disease-associated proinflammatory microglia. Conclusions These findings suggest that baicalein can reverse MPTP-induced neuroinflammation in mice by suppressing NLRP3/caspase-1/gasdermin D pathway. Our study provides potential insight into the use of baicalein in PD therapy.


2021 ◽  
Vol 11 (7) ◽  
pp. 895
Author(s):  
Karolina A. Bearss ◽  
Joseph F. X. DeSouza

Parkinson’s disease (PD) is a neurodegenerative disease that has a fast progression of motor dysfunction within the first 5 years of diagnosis, showing an annual motor rate of decline of the Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) between 5.2 and 8.9 points. We aimed to determine both motor and non-motor PD symptom progression while participating in dance classes once per week over a period of three years. Longitudinal data was assessed for a total of 32 people with PD using MDS-UPDRS scores. Daily motor rate of decline was zero (slope = 0.000146) in PD-Dancers, indicating no motor impairment, whereas the PD-Reference group showed the expected motor decline across three years (p < 0.01). Similarly, non-motor aspects of daily living, motor experiences of daily living, and motor complications showed no significant decline. A significant group (PD-Dancers and PD-Reference) by days interaction showed that PD who train once per week have less motor impairment (M = 18.75) than PD-References who do not train (M = 24.61) over time (p < 0.05). Training is effective at slowing both motor and non-motor PD symptoms over three years as shown in decreased scores of the MDS-UPDRS.


2021 ◽  
pp. 1-11
Author(s):  
Valentina Leta ◽  
Daniele Urso ◽  
Lucia Batzu ◽  
Daniel Weintraub ◽  
Nataliya Titova ◽  
...  

Background: Constipation is regarded as one of the prodromal features of Parkinson’s disease (PD) and there is emerging evidence linking gastrointestinal dysfunction and cognitive impairment (CI) in PD. Objective: We explored whether constipation is associated with development of CI in two independent cohorts of de novo PD patients (n = 196 from the Non-motor International Longitudinal Study [NILS] and n = 423 from the Parkinson’s Progression Markers Initiative [PPMI] study). Methods: Constipation was clinically defined using the Non-Motor Symptoms Scale (NMSS) item-21 [NILS] and Scales for Outcomes in PD-Autonomic (SCOPA-AUT) item-5 [PPMI]. We assessed baseline group differences (PD with or without constipation) in CI, global non-motor symptoms burden, motor dysfunction, and striatal dopaminergic denervation. Kaplan-Meier method estimated group differences in cumulative proportion of patients with incident CI over three years. In PPMI, we subsequently performed univariate and multivariate Cox survival analyses to evaluate whether constipation predicts incident mild cognitive impairment or dementia over a 6-year period, including constipation and other known predictors of CI as covariates. Results: Patients with constipation had greater motor and global non-motor burden in both cohorts at baseline (p <  0.05). Kaplan-Meier plots showed faster conversion to CI in patients with constipation in both cohorts (p <  0.05). In PPMI, 37 subjects developed dementia during a mean follow-up of 4.9 years, and constipation was an independent predictor of dementia onset (hazard ratio = 2.311; p = 0.02). Conclusion: Constipation in de novo PD patients is associated with development of cognitive decline and may serve as a clinical biomarker for identification of patients at risk for cognitive impairment.


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