scholarly journals Triggering Receptor Expressed on Myeloid Cells 2 Protects Dopaminergic Neurons by Promoting Autophagy in the Inflammatory Pathogenesis of Parkinson’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Wei Huang ◽  
Qiankun Lv ◽  
Yunfei Xiao ◽  
Zhen Zhong ◽  
Binbin Hu ◽  
...  

Parkinson’s disease is a neurodegenerative disorder with an inflammatory response as the core pathogenic mechanism. Previous human genetics findings support the view that the loss of TREM2 function will aggravate neurodegeneration, and TREM2 is one of the most highly expressed receptors in microglia. However, the role of TREM2 in the inflammatory mechanism of PD is not clear. In our study, it was found both in vivo and in vitro that the activation of microglia not only promoted the secretion of inflammatory factors but also decreased the level of TREM2 and inhibited the occurrence of autophagy. In contrast, an increase in the level of TREM2 decreased the expression of inflammatory factors and enhanced the level of autophagy through the p38 MAPK/mTOR pathway. Moreover, increased TREM2 expression significantly decreased the apoptosis of dopaminergic (DA) neurons and improved the motor ability of PD mice. In summary, TREM2 is an important link between the pathogenesis of PD and inflammation. Our study provides a new view for the mechanism of TREM2 in PD and reveals TREM2 as a potential therapeutic target for PD.

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3022
Author(s):  
Maria Vizziello ◽  
Linda Borellini ◽  
Giulia Franco ◽  
Gianluca Ardolino

The progressive reduction of the dopaminergic neurons of the substantia nigra is the fundamental process underlying Parkinson’s disease (PD), while the mechanism of susceptibility of this specific neuronal population is largely unclear. Disturbances in mitochondrial function have been recognized as one of the main pathways in sporadic PD since the finding of respiratory chain impairment in animal models of PD. Studies on genetic forms of PD have provided new insight on the role of mitochondrial bioenergetics, homeostasis, and autophagy. PINK1 (PTEN-induced putative kinase 1) gene mutations, although rare, are the second most common cause of recessively inherited early-onset PD, after Parkin gene mutations. Our knowledge of PINK1 and Parkin function has increased dramatically in the last years, with the discovery that a process called mitophagy, which plays a key role in the maintenance of mitochondrial health, is mediated by the PINK1/Parkin pathway. In vitro and in vivo models have been developed, supporting the role of PINK1 in synaptic transmission, particularly affecting dopaminergic neurons. It is of paramount importance to further define the role of PINK1 in mitophagy and mitochondrial homeostasis in PD pathogenesis in order to delineate novel therapeutic targets.


2020 ◽  
Vol 21 (22) ◽  
pp. 8421
Author(s):  
Chrysoula Marogianni ◽  
Maria Sokratous ◽  
Efthimios Dardiotis ◽  
Georgios M. Hadjigeorgiou ◽  
Dimitrios Bogdanos ◽  
...  

Parkinson’s disease (PD) is a neurodegenerative disorder, caused by, so far, unknown pathogenetic mechanisms. There is no doubt that pro-inflammatory immune-mediated mechanisms are pivotal to the pathogenicity and progression of the disease. In this review, we highlight the binary role of microglia activation in the pathophysiology of the disorder, both neuroprotective and neuromodulatory. We present how the expression of several cytokines implicated in dopaminergic neurons (DA) degeneration could be used as biomarkers for PD. Viral infections have been studied and correlated to the disease progression, usually operating as trigger factors for the inflammatory process. The gut–brain axis and the possible contribution of the peripheral bowel inflammation to neuronal death, mainly dopaminergic neurons, seems to be a main contributor of brain neuroinflammation. The role of the immune system has also been analyzed implicating a-synuclein in the activation of innate and adaptive immunity. We also discuss therapeutic approaches concerning PD and neuroinflammation, which have been studied in experimental and in vitro models and data stemming from epidemiological studies.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Huynh Kim Thoa Truong ◽  
Man Anh Huynh ◽  
My Dung Vuu ◽  
Thi Phuong Thao Dang

Parkinson’s disease (PD), which is characterized by the decreased motor function and the loss of dopaminergic neurons, is a common neurodegenerative disorder in elders. There have been numerous in vitro and in vivo models developed to study mechanisms of PD and screen potential drug. Recently, dUCH-knockdown Drosophila model has been established and showed potential for screening antioxidants for PD treatment. The dUCH-knockdown Drosophila model of PD mimics most of main PD pathologies such as dopaminergic neurons degeneration, locomotor dysfunction, and shortage of dopamine in the brain. Common purslane (Portulaca oleracea L.) is a nutritious vegetable containing a variety of antioxidants, levodopa, and dopamine, a neurotransmitter closely related to PD. Purslane has been reported to exert neuroprotective effects against several neurotoxins including rotenone and 6-OHDA in PD models. However, the recent data have not provided sufficient evidence for using purslane to treat PD or decelerate disease progression. Therefore, in this study, we utilized dUCH-knockdown fly to evaluate the capacity of purslane extracts for PD treatment. The results showed that purslane extracts improved locomotor ability in the larval stage and decelerated disease progression in the adult stage. Additionally, purslane extracts also reduced dopaminergic neuron degeneration. Taken together, our data strongly demonstrated that purslane extracts effectively rescued PD-like phenotypes in the fly model. This result contributed a foundation for further study on the application of purslane in PD treatment.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Zinger ◽  
Carlos Barcia ◽  
Maria Trinidad Herrero ◽  
Gilles J. Guillemin

Parkinson’s disease (PD) is a common neurodegenerative disorder characterised by loss of dopaminergic neurons and localized neuroinflammation occurring in the midbrain several years before the actual onset of symptoms. Activated microglia themselves release a large number of inflammatory mediators thus perpetuating neuroinflammation and neurotoxicity. The Kynurenine pathway (KP), the main catabolic pathway for tryptophan, is one of the major regulators of the immune response and may also be implicated in the inflammatory response in parkinsonism. The KP generates several neuroactive compounds and therefore has either a neurotoxic or neuroprotective effect. Several of these molecules produced by microglia can activate the N-methyl-D-aspartate (NMDA) receptor-signalling pathway, leading to an excitotoxic response. Previous studies have shown that NMDA antagonists can ease symptoms and exert a neuroprotective effect in PD bothin vivoandin vitro. There are to date several lines of evidence linking some of the KP intermediates and the neuropathogenesis of PD. Moreover, it is likely that pharmacological modulation of the KP will represent a new therapeutic strategy for PD.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Renrong Wei ◽  
Cuiping Rong ◽  
Qingfeng Xie ◽  
Shouhai Wu ◽  
Yuchao Feng ◽  
...  

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.


2020 ◽  
Author(s):  
Eiji Inoue ◽  
Takahiro Suzuki ◽  
Yasuharu Shimizu ◽  
Keiichi Sudo ◽  
Haruhisa Kawasaki ◽  
...  

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.


Author(s):  
Love Kumar

Parkinson’s disease (PD) is a common known neurodegenerative disorder with unknown etiology. It was estimated about 0.3% prevalence in the U.S population and enhance to 4 to 5% in older than 85 years. All studies were depending on the molecular docking where all ligands and protein PARK7 (PDB ID: 2RK3) were interacted by docked process. Some natural compounds was selected such as Harmine, Alloxan, Alpha spinasterol, Myrcene, and Vasicinone and PARK7 (PDB ID: 2RK3) protein. According to the PyRx and SWISS ADME result, Harmine was the only ligand which was showing minimum binding affinity. AutoDock Vina software was used for docking process between ligand (Harmine) and receptor protein PARK7 (PDB ID: 2RK3). The result was visualized under PyMol. Harmine was inhibiting the activity of PARK7 (PDB ID: 2RK3) and it may be used for the treatment of PD in future prospect after its in vitro and in vivo studies.


2018 ◽  
Author(s):  
Markus Riessland ◽  
Benjamin Kolisnyk ◽  
Tae Wan Kim ◽  
Jia Cheng ◽  
Jason Ni ◽  
...  

AbstractCellular senescence is a mechanism used by mitotic cells to prevent uncontrolled cell division. As senescent cells persist in tissues, they cause local inflammation and are harmful to surrounding cells, contributing to aging. Generally, neurodegenerative diseases, such as Parkinson‘s, are disorders of aging. The contribution of cellular senescence to neurodegeneration is still unclear. SATB1 is a DNA binding protein associated with Parkinson’s disease. We report that SATB1 prevents cellular senescence in post-mitotic dopaminergic neurons. Loss of SATB1 causes activation of a cellular senescence transcriptional program in dopamine neurons, both in human stem cell-derived dopaminergic neurons and in mice. We observed phenotypes which are central to cellular senescence in SATB1 knockout dopamine neurons in vitro and in vivo. Moreover, we found that SATB1 directly represses expression of the pro-senescence factor, p21, in dopaminergic neurons. Our data implicate senescence of dopamine neurons as a contributing factor to the pathology of Parkinson’s disease.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Shankar J. Chinta ◽  
Subramanian Rajagopalan ◽  
Abirami Ganesan ◽  
Julie K. Andersen

Parkinson’s disease (PD) is an age-related neurodegenerative disorder characterized in part by the preferential loss of nigrostriatal dopaminergic neurons. Although the precise etiology of PD is unknown, accumulating evidence suggests that PD involves microglial activation that exerts neurotoxic effects through production of proinflammatory cytokines and increased oxidative and nitrosative stress. Thus, controlling microglial activation has been suggested as a therapeutic target for combating PD. Previously we demonstrated that pharmacological inhibition of a class of enzymes known as prolyl hydroxylases via 3,4-dihydroxybenzoate administration protected against MPTP-induced neurotoxicity, however the exact mechanisms involved were not elucidated. Here we show that this may be due to DHB’s ability to inhibit microglial activation. DHB significantly attenuated LPS-mediated induction of nitric oxide synthase and pro-inflammatory cytokines in murine BV2 microglial cellsin vitroin conjunction with reduced ROS production and activation of NFκB and MAPK pathways possibly due to up-regulation of HO-1 levels. HO-1 inhibition partially abrogates LPS-mediated NFκB activity and subsequent NO induction.In vivo, DHB pre-treatment suppresses microglial activation elicited by MPTP treatment. Our results suggest that DHB’s neuroprotective properties could be due to its ability to dampen induction of microglial activation via induction of HO-1.


2015 ◽  
Vol 73 ◽  
pp. 150-162 ◽  
Author(s):  
Kim-Ann Saal ◽  
Jan C. Koch ◽  
Lars Tatenhorst ◽  
Éva M. Szegő ◽  
Vinicius Toledo Ribas ◽  
...  

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