miR-7 Controls the Dopaminergic/Oligodendroglial Fate through Wnt/β-catenin Signaling Regulation

During the development of the central nervous system, the proliferation of neural progenitors and differentiation of neurons and glia are tightly regulated by different transcription factors and signaling cascades, such as the Wnt and Shh pathways. This process takes place in cooperation with several microRNAs, some of which evolutionarily conserved in vertebrates, from teleosts to mammals. We focused our attention on miR-7, as its role in the regulation of cell signaling during neural development is still unclear. Specifically, we used human stem cell cultures and whole zebrafish embryos to study, in vitro and in vivo, the role of miR-7 in the development of dopaminergic (DA) neurons, a cell type primarily affected in Parkinson’s disease. We demonstrated that the zebrafish homologue of miR-7 (miR-7a) is expressed in the forebrain during the development of DA neurons. Moreover, we identified 143 target genes downregulated by miR-7, including the neural fate markers TCF4 and TCF12, as well as the Wnt pathway effector TCF7L2. We then demonstrated that miR-7 negatively regulates the proliferation of DA-progenitors by inhibiting Wnt/β-catenin signaling in zebrafish embryos. In parallel, miR-7 positively regulates Shh signaling, thus controlling the balance between oligodendroglial and DA neuronal cell fates. In summary, this study identifies a new molecular cross-talk between Wnt and Shh signaling pathways during the development of DA-neurons. Being mediated by a microRNA, this mechanism represents a promising target in cell differentiation therapies for Parkinson’s disease.

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Protective effects of saffron and its constituent crocetin to motor symptoms, short life span and rough-eyed phenotypes in the fly models of Parkinson’s disease in vivo

10.1101/2020.12.06.408997 ◽

2020 ◽

Author(s):

Eiji Inoue ◽

Takahiro Suzuki ◽

Yasuharu Shimizu ◽

Keiichi Sudo ◽

Haruhisa Kawasaki ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Life Span ◽

Neurodegenerative Disorder ◽

Neuronal Cell ◽

Crocus Sativus ◽

Motor Symptoms ◽

Protective Effects

AbstractParkinson’s disease (PD) is a common neurodegenerative disorder with motor symptoms linked to the loss of dopaminergic neurons in the brain. α-Synuclein is an aggregation-prone neural protein that plays a role in the pathogenesis of PD. In our previous paper, we found that saffron; the stigma of Crocus sativus Linné (Iridaceae), and its constituents (crocin and crocetin) suppressed aggregation of α-synuclein and promoted the dissociation of α-synuclein fibrils in vitro. In this study, we investigated the effect of dietary saffron and its constituent, crocetin, in vivo on a fly PD model overexpressing several mutant α-synuclein in a tissue-specific manner. Saffron and crocetin significantly suppressed the decrease of climbing ability in the Drosophila overexpressing A30P (A30P fly PD model) or G51D (G51D fly PD model) mutated α-synuclein in neurons. Saffron and crocetin extended the life span in the G51D fly PD model. Saffron suppressed the rough-eyed phenotype and the dispersion of the size histogram of the ocular long axis in A30P fly PD model in eye. Saffron had a cytoprotective effect on a human neuronal cell line with α-synuclein fibrils. These data showed that saffron and its constituent crocetin have protective effects on the progression of PD disease in animals in vivo and suggest that saffron and crocetin can be used to treat PD.

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Gsk3β and Tomm20 are substrates of the SCFFbxo7/PARK15 ubiquitin ligase associated with Parkinson's disease

Biochemical Journal ◽

10.1042/bcj20160387 ◽

2016 ◽

Vol 473 (20) ◽

pp. 3563-3580 ◽

Cited By ~ 15

Author(s):

Felipe Roberti Teixeira ◽

Suzanne J. Randle ◽

Shachi P. Patel ◽

Tycho E.T. Mevissen ◽

Grasilda Zenkeviciute ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Ubiquitin Ligase ◽

Glycogen Synthase ◽

Neuronal Cell ◽

Ubiquitin Chain ◽

Cell Parameters ◽

Apoptosis Protein

Fbxo7 is a clinically relevant F-box protein, associated with both cancer and Parkinson's disease (PD). Additionally, SNPs within FBXO7 are correlated with alterations in red blood cell parameters. Point mutations within FBXO7 map within specific functional domains, including near its F-box domain and its substrate recruiting domains, suggesting that deficiencies in SCFFbxo7/PARK15 ubiquitin ligase activity are mechanistically linked to early-onset PD. To date, relatively few substrates of the ligase have been identified. These include HURP (hepatoma up-regulated protein), whose ubiquitination results in proteasome-mediated degradation, and c-IAP1 (inhibitor of apoptosis protein 1), TNF receptor-associated factor 2 (TRAF2), and NRAGE, which are not destabilized as a result of ubiquitination. None of these substrates have been linked directly to PD, nor has it been determined whether they would directly engage neuronal cell death pathways. To discover ubiquitinated substrates of SCFFbxo7 implicated more directly in PD aetiology, we conducted a high-throughput screen using protein arrays to identify new candidates. A total of 338 new targets were identified and from these we validated glycogen synthase kinase 3β (Gsk3β), which can phosphorylate α-synuclein, and translocase of outer mitochondrial membrane 20 (Tomm20), a mitochondrial translocase that, when ubiquitinated, promotes mitophagy, as SCFFbxo7 substrates both in vitro and in vivo. Ubiquitin chain restriction analyses revealed that Fbxo7 modified Gsk3β using K63 linkages. Our results indicate that Fbxo7 negatively regulates Gsk3β activity, rather than its levels or localization. In addition, Fbxo7 ubiquitinated Tomm20, and its levels correlated with Fbxo7 expression, indicating a stabilizing effect. None of the PD-associated mutations in Fbxo7 impaired Tomm20 ubiquitination. Our findings demonstrate that SCFFbxo7 has an impact directly on two proteins implicated in pathological processes leading to PD.

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A novel nanoparticle system targeting damaged mitochondria for the treatment of Parkinson's disease

10.21203/rs.3.rs-989619/v1 ◽

2021 ◽

Author(s):

Yue Chen ◽

Lina Yu ◽

Jinyu Zhang ◽

Lifen Yao ◽

Hongji Yan ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Mitochondrial Function ◽

Neuronal Cell Death ◽

Neuronal Cell ◽

Mitochondrial Damage ◽

Irreversible Damage ◽

Novel Strategy

Abstract BackgroundMitochondrial damage is one of the primary causes of neuronal cell death in Parkinson's disease (PD). In PD patients, the mitochondrial damage can be repaired or irreversible. Therefore, mitochondrial damage repair becomes a promising strategy for PD treatment.MethodsWe use hyaluronic acid nanoparticles (HA-NPs) of different molecular weights to protect the mitochondria and salvages the mild and limited damage in mitochondria. Our HA-NPs with 2,190 kDa HA can improve the mitochondrial function of SH-SY5Y cells and PTEN induced putative kinase 1 (PINK1) knockout mouse embryo fibroblast (MEF) cells. In cases of irreversible damage, we use NPs with ubiquitin specific peptidase 30 (USP30) siRNA to promote mitophagy. Meanwhile, by adding PINK1 antibodies, our NPs can selectively target the irreversibly damaged mitochondria, preventing the excessive clearance of healthy mitochondria.ResultsOur HA-NPs with 2,190 kDa HA can protect the mitochondria and salvage the mitochondrial function of the mild and limited damage conditions in both SH-SY5Y cells and PINK1 knockout MEF cells. NPs with USP30 siRNA and PINK1 antibodies can selectively target and promote the clearance of irreversibly damaged mitochondria both in vitro and in vivo.ConclusionsWe successfully designed and developed NPs for the treatment of PD that can target different stages of mitochondrial damage. This strategy is expected to overcome the problems associated with the excessive clearance of healthy mitochondria and has great potential for clinical applications. Our study provides a novel strategy for PD treatment.

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Grafts Derived from an α-Synuclein Triplication Patient Mediate Functional Recovery but Develop Disease-Associated Pathology in the 6-OHDA Model of Parkinson’s Disease

Journal of Parkinson s Disease ◽

10.3233/jpd-202366 ◽

2020 ◽

pp. 1-14

Author(s):

Shelby Shrigley ◽

Fredrik Nilsson ◽

Bengt Mattsson ◽

Alessandro Fiorenzano ◽

Janitha Mudannayake ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cell Lines ◽

Functional Recovery ◽

Embryonic Stem ◽

Hesc Line ◽

Alternative Source ◽

And Function

Background: Human induced pluripotent stem cells (hiPSCs) have been proposed as an alternative source for cell replacement therapy for Parkinson’s disease (PD) and they provide the option of using the patient’s own cells. A few studies have investigated transplantation of patient-derived dopaminergic (DA) neurons in preclinical models; however, little is known about the long-term integrity and function of grafts derived from patients with PD. Objective: To assess the viability and function of DA neuron grafts derived from a patient hiPSC line with an α-synuclein gene triplication (AST18), using a clinical grade human embryonic stem cell (hESC) line (RC17) as a reference control. Methods: Cells were differentiated into ventral mesencephalic (VM)-patterned DA progenitors using an established GMP protocol. The progenitors were then either terminally differentiated to mature DA neurons in vitro or transplanted into 6-hydroxydopamine (6-OHDA) lesioned rats and their survival, maturation, function, and propensity to develop α-synuclein related pathology, were assessed in vivo. Results: Both cell lines generated functional neurons with DA properties in vitro. AST18-derived VM progenitor cells survived transplantation and matured into neuron-rich grafts similar to the RC17 cells. After 24 weeks, both cell lines produced DA-rich grafts that mediated full functional recovery; however, pathological changes were only observed in grafts derived from the α-synuclein triplication patient line. Conclusion: This data shows proof-of-principle for survival and functional recovery with familial PD patient-derived cells in the 6-OHDA model of PD. However, signs of slowly developing pathology warrants further investigation before use of autologous grafts in patients.

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Cytokinin Plant Hormones Have Neuroprotective Activity in In Vitro Models of Parkinson’s Disease

Molecules ◽

10.3390/molecules26020361 ◽

2021 ◽

Vol 26 (2) ◽

pp. 361

Author(s):

Gabriel Gonzalez ◽

Jiří Grúz ◽

Cosimo Walter D’Acunto ◽

Petr Kaňovský ◽

Miroslav Strnad

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Cell Death ◽

Neuronal Cell Death ◽

Disease Model ◽

Neuronal Cell ◽

Zeatin Riboside ◽

Neuroprotective Activity ◽

Protective Activity

Cytokinins are adenine-based phytohormones that regulate key processes in plants, such as cell division and differentiation, root and shoot growth, apical dominance, branching, and seed germination. In preliminary studies, they have also shown protective activities against human neurodegenerative diseases. To extend knowledge of the protection (protective activity) they offer, we investigated activities of natural cytokinins against salsolinol (SAL)-induced toxicity (a Parkinson’s disease model) and glutamate (Glu)-induced death of neuron-like dopaminergic SH-SY5Y cells. We found that kinetin-3-glucoside, cis-zeatin riboside, and N6-isopentenyladenosine were active in the SAL-induced PD model. In addition, trans-, cis-zeatin, and kinetin along with the iron chelator deferoxamine (DFO) and the necroptosis inhibitor necrostatin 1 (NEC-1) significantly reduced cell death rates in the Glu-induced model. Lactate dehydrogenase assays revealed that the cytokinins provided lower neuroprotective activity than DFO and NEC-1. Moreover, they reduced apoptotic caspase-3/7 activities less strongly than DFO. However, the cytokinins had very similar effects to DFO and NEC-1 on superoxide radical production. Overall, they showed protective activity in the SAL-induced model of parkinsonian neuronal cell death and Glu-induced model of oxidative damage mainly by reduction of oxidative stress.

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Neuroprotective Effect of Optimized Yinxieling Formula in 6-OHDA-Induced Chronic Model of Parkinson’s Disease through the Inflammation Pathway

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2019/2529641 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Renrong Wei ◽

Cuiping Rong ◽

Qingfeng Xie ◽

Shouhai Wu ◽

Yuchao Feng ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Calcium Binding ◽

Dopaminergic Neurons ◽

Neuroprotective Effect ◽

Interleukin 1 ◽

Mrna Levels ◽

Cox 2

Parkinson’s disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra (SN)-striatum circuit, which is associated with glial activation and consequent chronic neuroinflammation. Optimized Yinxieling Formula (OYF) is a Chinese medicine that exerts therapeutical effect and antiinflammation property on psoriasis. Our previous study has proven that pretreatment with OYF could regulate glia-mediated inflammation in an acute mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Given that PD is a chronic degeneration disorder, this study applied another PD animal model induced by striatal injection of 6-hydroxydopamine (6-OHDA) to mimic the progressive damage of the SN-striatum dopamine system in rats. The OYF was administrated in the manner of pretreatment plus treatment. The effects of the OYF on motor behaviors were assessed with the apomorphine-induced rotation test and adjusting steps test. To confirm the effect of OYF on dopaminergic neurons and glia activation in this model, we analyzed the expression of tyrosine hydroxylase (TH) and glia markers, ionized calcium-binding adapter molecule 1 (Iba-1), and glial fibrillary acidic protein (GFAP) in the SN region of the rat PD model. Inflammation-associated factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), were further evaluated in this model and in interferon-γ- (INF-γ-) induced murine macrophages RAW264.7 cells. The results from the in vivo study showed that OYF reversed the motor behavioral dysfunction in 6-OHDA-induced PD rats, upregulated the TH expression, decreased the immunoreactivity of Iba-1 and GFAP, and downregulated the mRNA levels of TNF-α and COX-2. The OYF also trended to decrease the mRNA levels of IL-1β and iNOS in vivo. The results from the in vitro study showed that OYF significantly decreased the mRNA levels of TNF-α, IL-1β, IL-6, iNOS, and COX-2. Therefore, this study suggests that OYF exerts antiinflammatory effects, which might be related to the protection of dopaminergic neurons in 6-OHDA-induced chronic neurotoxicity.

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Simvastatin Prevents Neurodegeneration in the MPTP Mouse Model of Parkinson’s Disease via Inhibition of A1 Reactive Astrocytes

NeuroImmunoModulation ◽

10.1159/000513678 ◽

2021 ◽

pp. 1-8

Author(s):

Ren-Wei Du ◽

Wen-Guang Bu

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Mouse Model ◽

Underlying Mechanism ◽

Reactive Astrocytes ◽

Dopamine Neurons ◽

Neuron Death ◽

Neurologic Disorders

Emerging evidence indicates that A1 reactive astrocytes play crucial roles in the pathogenesis of Parkinson’s disease (PD). Thus, development of agents that could inhibit the formation of A1 reactive astrocytes could be used to treat PD. Simvastatin has been touted as a potential neuroprotective agent for neurologic disorders such as PD, but the specific underlying mechanism remains unclear. The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD and primary astrocytes/neurons were prepared to investigate the effects of simvastatin on PD and its underlying mechanisms in vitro and in vivo. We show that simvastatin protects against the loss of dopamine neurons and behavioral deficits in the MPTP mouse model of PD. We also found that simvastatin suppressed the expression of A1 astrocytic specific markers in vivo and in vitro. In addition, simvastatin alleviated neuron death induced by A1 astrocytes. Our findings reveal that simvastatin is neuroprotective via the prevention of conversion of astrocytes to an A1 neurotoxic phenotype. In light of simvastatin favorable properties, it should be evaluated in the treatment of PD and related neurologic disorders characterized by A1 reactive astrocytes.

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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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