Systemic activation of NLRP3 inflammasome and plasma α-synuclein levels are correlated with motor severity and progression in Parkinson’s disease

Abstract Background Emerging evidence indicates that inflammasome-induced inflammation plays a crucial role in the pathogenesis of Parkinson’s disease (PD). Several proteins including α-synuclein trigger the activation of NLRP3 inflammasome. However, few studies examined whether inflammasomes are activated in the periphery of PD patients and their possible value in the diagnosis or tracking of the progress of PD. The aim of this study was to determine the association between inflammasome-induced inflammation and clinical features in PD. Methods There were a total of 67 participants, including 43 patients with PD and 24 controls, in the study. Participants received a complete evaluation of motor and non-motor symptoms, including Hoehn and Yahr (H-Y) staging scale. Blood samples were collected from all participants. The protein and mRNA expression levels of inflammasomes subtypes and components in peripheral blood mononuclear cells (PBMCs) were determined using western blotting and RT-qPCR. We applied Meso Scale Discovery (MSD) immunoassay to measure the plasma levels of IL-1β and α-synuclein. Results We observed increased gene expression of NLRP3, ASC, and caspase-1 in PBMCs, and increased protein levels of NLRP3, caspase-1, and IL-1β in PD patients. Plasma levels of IL-1β were significantly higher in patients with PD compared with controls and have a positive correlation with H-Y stage and UPDRS part III scores. Furthermore, plasma α-synuclein levels were also increased in PD patients and have a positive correlation with both UPDRS part III scores and plasma IL-1β levels. Conclusions Our data demonstrated that the NLRP3 inflammasome is activated in the PBMCs from PD patients. The related inflammatory cytokine IL-1β and total α-synuclein in plasma were increased in PD patients than controls, and both of them presented a positive correlation with motor severity in patients with PD. Furthermore, plasma α-synuclein levels have a positive correlation with IL-1β levels in PD patients. All these findings suggested that the NLRP3 inflammasome activation-related cytokine IL-1β and α-synuclein could serve as non-invasive biomarkers to monitor the severity and progression of PD in regard to motor function.

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Plasma-borne indicators of inflammasome activity in Parkinson’s disease patients

npj Parkinson s Disease ◽

10.1038/s41531-020-00147-6 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Faith L. Anderson ◽

Katharine M. von Herrmann ◽

Angeline S. Andrew ◽

Yuliya I. Kuras ◽

Alison L. Young ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cell Death ◽

Nlrp3 Inflammasome ◽

Neurodegenerative Disorder ◽

Early Stage ◽

Inflammasome Activation ◽

Membrane Pore ◽

Related Proteins ◽

Inflammasome Activity

AbstractParkinson’s disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms and loss of dopaminergic neurons of the substantia nigra. Inflammation and cell death are recognized aspects of PD suggesting that strategies to monitor and modify these processes may improve the management of the disease. Inflammasomes are pro-inflammatory intracellular pattern recognition complexes that couple these processes. The NLRP3 inflammasome responds to sterile triggers to initiate pro-inflammatory processes characterized by maturation of inflammatory cytokines, cytoplasmic membrane pore formation, vesicular shedding, and if unresolved, pyroptotic cell death. Histologic analysis of tissues from PD patients and individuals with nigral cell loss but no diagnosis of PD identified elevated expression of inflammasome-related proteins and activation-related “speck” formation in degenerating mesencephalic tissues compared with controls. Based on previous reports of circulating inflammasome proteins in patients suffering from heritable syndromes caused by hyper-activation of the NLRP3 inflammasome, we evaluated PD patient plasma for evidence of inflammasome activity. Multiple circulating inflammasome proteins were detected almost exclusively in extracellular vesicles indicative of ongoing inflammasome activation and pyroptosis. Analysis of plasma obtained from a multi-center cohort identified elevated plasma-borne NLRP3 associated with PD status. Our findings are consistent with others indicating inflammasome activity in neurodegenerative disorders. Findings suggest mesencephalic inflammasome protein expression as a histopathologic marker of early-stage nigral degeneration and suggest plasma-borne inflammasome-related proteins as a potentially useful class of biomarkers for patient stratification and the detection and monitoring of inflammation in PD.

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Pharmacological Blocker of NF-κb and Mitochondrial Ros Restrict NLRP3 Inflammasome Activation and Rescue Dopaminergic Neurons in Vitro and in Vivo Parkinson’s Disease

10.21203/rs.3.rs-260478/v1 ◽

2021 ◽

Author(s):

Sahabuddin Ahmed ◽

Samir Ranjan Panda ◽

Mohit Kwatra ◽

Bidya Dhar Sahu ◽

VGM Naidu

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Free Radicals ◽

Nlrp3 Inflammasome ◽

Nuclear Translocation ◽

Inflammasome Activation ◽

Mitochondrial Ros ◽

Nlrp3 Inflammasome Activation

Abstract Several activators of NLRP3 inflammasome have been described; however, the central mechanisms of NLRP3 inflammasome activation in brain microglia, especially at the activating step through free radical generation, still require further clarification. Hence the present study aimed to investigate the role of free radicals in activating NLRP3 inflammasome driven neurodegeneration and elucidated the neuroprotective role of perillyl alcohol (PA) in vitro and in vivo models of Parkinson’s disease. Initial priming of microglial cells with lipopolysaccharide (LPS) following treatment with hydrogen peroxide (H2O2) induces NF-κB translocation to nucleus with robust generation of free radicals that act as Signal 2 in augmenting NLRP3 inflammasome assembly and its downstream targets. PA treatment suppresses nuclear translocation of NF-κB and maintains cellular redox homeostasis in microglia that limits NLRP3 inflammasome activation along with processing active caspase-1, IL-1β and IL-18. To further correlates the in vitro study with in vivo MPTP model, treatment with PA also inhibits the nuclear translocation of NF-κB and downregulates the NLRP3 inflammasome activation. PA administration upregulates various antioxidant enzymes levels and restored the level of dopamine and other neurotransmitters in the striatum of the mice brain with improved behavioural activities. Additionally, treatment with Mito-TEMPO (a mitochondrial ROS inhibitor) was also seen to inhibit NLRP3 inflammasome and rescue dopaminergic neuron loss in the mice brain. Therefore, we conclude that NLRP3 inflammasome activation requires a signal from damaged mitochondria for its activation. Further pharmacological scavenging of free radicals restricts microglia activation and simultaneously supports neuronal survival via targeting NLRP3 inflammasome pathway in Parkinson’s disease.

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Bruton’s tyrosine kinase drives neuroinflammation and anxiogenic behavior in mouse models of stress

Journal of Neuroinflammation ◽

10.1186/s12974-021-02322-9 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Simantini Ghosh ◽

Zaidan Mohammed ◽

Itender Singh

Keyword(s):

Mouse Models ◽

Peripheral Blood Mononuclear Cells ◽

Nlrp3 Inflammasome ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Specific Inhibitor ◽

Inflammasome Activation ◽

Peripheral Blood Mononuclear ◽

Caspase 1 ◽

Nlrp3 Inflammasome Activation

Abstract Background Current therapies targeting several neurotransmitter systems are only able to partially mitigate the symptoms of stress- and trauma-related disorder. Stress and trauma-related disorders lead to a prominent inflammatory response in humans, and in pre-clinical models. However, mechanisms underlying the induction of neuroinflammatory response in PTSD and anxiety disorders are not clearly understood. The present study investigated the mechanism underlying the activation of proinflammatory NLRP3 inflammasome and IL1β in mouse models of stress. Methods We used two mouse models of stress, i.e., mice subjected to physical restraint stress with brief underwater submersion, and predator odor stress. Mice were injected with MCC950, a small molecule specific inhibitor of NLRP3 activation. To pharmacologically inhibit BTK, a specific inhibitor ibrutinib was used. To validate the observation from ibrutinib studies, a separate group of mice was injected with another BTK-specific inhibitor LFM-A13. Seven days after the induction of stress, mice were examined for anxious behavior using open field test (OFT), light–dark test (LDT), and elevated plus maze test (EPM). Following the behavior tests, hippocampus and amygdale were extracted and analyzed for various components of NLRP3–caspase 1–IL1β pathway. Plasma and peripheral blood mononuclear cells were also used to assess the induction of NLRP3–Caspase 1–IL-1β pathway in stressed mice. Results Using two different pre-clinical models of stress, we demonstrate heightened anxious behavior in female mice as compared to their male counterparts. Stressed animals exhibited upregulation of proinflammatory IL1β, IL-6, Caspase 1 activity and NLRP3 inflammasome activation in brain, which were significantly higher in female mice. Pharmacological inhibition of NLRP3 inflammasome activation led to anxiolysis as well as attenuated neuroinflammatory response. Further, we observed induction of activated Bruton’s tyrosine kinase (BTK), an upstream positive-regulator of NLRP3 inflammasome activation, in hippocampus and amygdala of stressed mice. Next, we conducted proof-of-concept pharmacological BTK inhibitor studies with ibrutinib and LFM-A13. In both sets of experiments, we found BTK inhibition led to anxiolysis and attenuated neuroinflammation, as indicated by significant reduction of NLRP3 inflammasome and proinflammatory IL-1β in hippocampus and amygdala. Analysis of plasma and peripheral blood mononuclear cells indicated peripheral induction of NLRP3–caspase 1–IL1β pathway in stressed mice. Conclusion Our study identified BTK as a key upstream regulator of neuroinflammation, which drives anxiogenic behavior in mouse model of stress. Further, we demonstrated the sexually divergent activation of BTK, providing a clue to heightened neuroinflammation and anxiogenic response to stress in females as compared to their male counterparts. Our data from the pharmacological inhibition studies suggest BTK as a novel target for the development of potential clinical treatment of PTSD and anxiety disorders. Induction of pBTK and NLRP3 in peripheral blood mononuclear cells of stressed mice suggest the potential effect of stress on systemic inflammation.

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Bushen-Yizhi Formula Alleviates Neuroinflammation via Inhibiting NLRP3 Inflammasome Activation in a Mouse Model of Parkinson’s Disease

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2018/3571604 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Yousheng Mo ◽

Erjin Xu ◽

Renrong Wei ◽

Baoluu Le ◽

Lei Song ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Mouse Model ◽

Nlrp3 Inflammasome ◽

Molecular Mechanisms ◽

Neuronal Degeneration ◽

Interleukin 1 ◽

Inflammasome Activation ◽

Neuroprotective Effects ◽

Nlrp3 Inflammasome Activation

Parkinson’s disease (PD), the second most common neurodegenerative disease, is characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Although the molecular mechanisms underlying dopaminergic neuronal degeneration in PD remain unclear, neuroinflammation is considered as the vital mediator in the pathogenesis and progression of PD. Bushen-Yizhi Formula (BSYZ), a traditional Chinese medicine, has been demonstrated to exert antineuroinflammation in our previous studies. However, it remains unclear whether BSYZ is effective for PD. Here, we sought to assess the neuroprotective effects and explore the underlying mechanisms of BSYZ in a 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine- (MPTP-) induced mouse model of PD. Our results indicate that BSYZ significantly alleviates the motor impairments and dopaminergic neuron degeneration of MPTP-treated mice. Furthermore, BSYZ remarkably attenuates microglia activation, inhibits NLPR3 activation, and decreases the levels of inflammatory cytokines in MPTP-induced mouse brain. Also, BSYZ inhibits NLRP3 activation and interleukin-1βproduction of the 1-methyl-4-phenyl-pyridinium (MPP+) stimulated BV-2 microglia cells. Taken together, our results indicate that BSYZ alleviates MPTP-induced neuroinflammation probably via inhibiting NLRP3 inflammasome activation in microglia. Collectively, BSYZ may be a potential therapeutic agent for PD and the related neurodegeneration diseases.

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Dopamine Signaling Modulates Microglial NLRP3 Inflammasome Activation: Implications for Parkinson’s Disease

10.21203/rs.3.rs-369002/v2 ◽

2021 ◽

Author(s):

Adrianne F. Pike ◽

Francesca Longhena ◽

Gaia Faustini ◽

Jean-Marc van Eik ◽

Iris Gombert ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Nlrp3 Inflammasome ◽

Critical Role ◽

Inflammasome Activation ◽

Human Microglia ◽

Dopaminergic Neurodegeneration ◽

Nlrp3 Inflammasome Activation ◽

Dopamine Signaling

Abstract Background: Parkinson’s disease (PD) is characterized by the loss of nigral dopaminergic neurons leading to impaired striatal dopamine signaling, α-synuclein- (α-syn-) rich inclusions, and neuroinflammation. Degenerating neurons are surrounded by activated microglia with increased secretion of interleukin-1β (IL-1β), driven largely by the NLRP3 inflammasome. A critical role for microglial NLRP3 inflammasome activation in the progression of both dopaminergic neurodegeneration and α-syn pathology has been demonstrated in parkinsonism mouse models. Fibrillar α-syn activates this inflammasome in mouse and human macrophages, and we have shown previously that the same holds true for primary human microglia. Dopamine blocks microglial NLRP3 inflammasome activation in the MPTP model, but its effects in this framework, highly relevant to PD, remain unexplored in primary human microglia and in other in vivo parkinsonism models. Methods: Biochemical techniques including quantification of IL-1β secretion and confocal microscopy were employed to gain insight into dopamine signaling-mediated inhibition of the NLRP3 inflammasome mechanism in primary human microglia and the SYN120 transgenic mouse model. Dopamine and related metabolites were applied to human microglia together with various inflammasome activating stimuli. The involvement of the receptors through which these catecholamines were predicted to act were assessed with agonists in both species. Results: We show in primary human microglia that dopamine, L-DOPA, and high extracellular K+, but not norepinephrine and epinephrine, block canonical, non-canonical, and α-syn-mediated NLRP3 inflammasome-driven IL-1β secretion. This suggests that dopamine acts as an inflammasome inhibitor in human microglia. Accordingly, we provide evidence that dopamine exerts its inhibitory effect through dopamine receptor D1 and D2 (DRD1 and DRD2) signaling. We also show that aged mice transgenic for human C-terminally truncated (1-120) α-syn (SYN120 tg mice) display increased NLRP3 inflammasome activation in comparison to WT mice that is diminished upon DRD1 agonism. Conclusions: Dopamine inhibits canonical, non-canonical, and α-syn-mediated activation of the NLRP3 inflammasome in primary human microglia, as does high extracellular K+. We suggest that dopamine serves as an endogenous repressor of the K+ efflux-dependent microglial NLRP3 inflammasome activation that contributes to dopaminergic neurodegeneration in PD, and that this reciprocation may account for the specific vulnerability of these neurons to disease pathology.

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

USURJ University of Saskatchewan Undergraduate Research Journal ◽

10.32396/usurj.v6i2.425 ◽

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.

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miR‐29c‐3p inhibits microglial NLRP3 inflammasome activation by targeting NFAT5 in Parkinson's disease

Genes to Cells ◽

10.1111/gtc.12764 ◽

2020 ◽

Vol 25 (6) ◽

pp. 364-374 ◽

Cited By ~ 1

Author(s):

Ruili Wang ◽

Qing Li ◽

Ya He ◽

Ying Yang ◽

Qiaoya Ma ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Nlrp3 Inflammasome ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation

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Cofactor-independent antiphospholipid antibodies activate the NLRP3-inflammasome via endosomal NADPH-oxidase: implications for the antiphospholipid syndrome

Thrombosis and Haemostasis ◽

10.1160/th14-07-0628 ◽

2015 ◽

Vol 113 (05) ◽

pp. 1071-1083 ◽

Cited By ~ 33

Author(s):

Nadine Müller-Calleja ◽

Antonia Köhler ◽

Benjamin Siebald ◽

Antje Canisius ◽

Carolin Orning ◽

...

Keyword(s):

Nadph Oxidase ◽

Antiphospholipid Syndrome ◽

Lupus Erythematosus ◽

Nlrp3 Inflammasome ◽

Antiphospholipid Antibodies ◽

Mononuclear Cells ◽

Inflammasome Activation ◽

Pregnancy Morbidity ◽

Caspase 1

SummaryThe antiphospholipid syndrome (APS) is an autoimmune disease characterised by thromboembolic events and/or pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). Here we show that three cofactor independent human monoclonal aPL can induce transcription of NLRP3 and caspase-1 resulting in inflammasome activation specific for NLRP3. This depends fully on activation of endosomal NADPH-oxidase-2 (NOX2) by aPL. Activation of NOX2 and subsequent inflammasome activation by aPL are independent from TLR2 or TLR4. While endosomal superoxide production induces caspase-1 and NLRP3 transcription, it does not affect prae-IL-1β transcription. Therefore, release of IL-1β occurs only after activation of additional pathways like TLR7/8 or TLR2. All effects exerted by the monoclonal aPL can be reproduced with IgG fractions of APS patients proving that the monoclonal aPL are representative for the APS. IgG fractions of healthy controls or patients suffering from systemic lupus erythematosus have no effect. In a mouse model of the APS we can show inflammasome activation in vivo. Furthermore, mononuclear cells isolated from patients with the APS show an increased expression of caspase-1 and NLRP3 which is accompanied by a three-fold increased serum concentration of IL-1β suggesting chronic inflammasome activation in APS patients. In summary, we provide further evidence that endosomal NOX2 can be activated by cofactor independent aPL. This leads to induction of the NLRP3 inflammasome. Our data indicate that cofactor independent aPL might contribute significantly to the pathogenesis of the APS.

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Pharmacological and Epigenetic Regulators of NLRP3 Inflammasome Activation in Alzheimer’s Disease

Pharmaceuticals ◽

10.3390/ph14111187 ◽

2021 ◽

Vol 14 (11) ◽

pp. 1187

Author(s):

Francesca La Rosa ◽

Roberta Mancuso ◽

Simone Agostini ◽

Federica Piancone ◽

Ivana Marventano ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Nlrp3 Inflammasome ◽

Mononuclear Cells ◽

Cytokine Production ◽

Protein Translation ◽

Inflammasome Activation ◽

Peripheral Blood Mononuclear ◽

Caspase 1 ◽

Inflammatory Status

Activation of the NLRP3 inflammasome complex results in the production of IL-18, Caspase-1 and IL-1β. These cytokines have a beneficial role in promoting inflammation, but an excessive activation of the inflammasome and the consequent constitutive inflammatory status is a negative factor in human pathologies including Alzheimer’s Disease (AD). MicroRNAs (miR-NAs) target the 3′UTR region of NLRP3, preventing the activation of the inflammasome and inhibiting cytokine production. Because Stavudine (D4T), an antiretroviral drug, was recently shown to reduce inflammasome activation, we verified whether its effect is mediated by miR-7-5p, miR-22-3p, miR-30e-5p and miR-223-3p: miRNAs that bind the NLRP3-mRNA-UTR region and interfere with protein translation, reducing NLRP3 activation. Peripheral blood mononuclear cells (PBMCs) of twenty AD patients and ten sex-matched Healthy Controls (HC) were stimulated with Lipopolysaccharides (LPS)+Amyloid-beta (Aβ42) in the absence/presence of D4T. Expression of genes within the inflammasome complex and of miRNAs was evaluated by RT-PCR; cytokines and caspase-1 production was measured by ELISA. Results have shown that: NLRP3, ASC, IL-1β and IL-18 expression, as well as IL-18, IL-1β and caspase-1 production, were significantly augmented (p < 0.05) in LPS+Aβ42-stimulated PBMCs of AD patients compared to HC. D4T reduced the expression of inflammasome genes and cytokine production (p < 0.005). miR-7-5p and miR-223-3p expression was significantly increased in LPS+Aβ42-stimulated PBMCs of AD patients (p < 0.05), and it was reduced by D4T in AD alone. In conclusion: miR-223-3p and mir-7-5p expression is increased in AD, but this does not result in down-regulation of NLRP3 inflammasome expression and of IL-1β and IL-18 production. D4T increased miRNA expression in HC but had an opposite effect in AD, suggesting that miRNA regulatory mechanisms are altered in AD.

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