Genetic analysis of Parkinson's disease-linked leucine-rich repeat kinase 2

2012 ◽  
Vol 40 (5) ◽  
pp. 1042-1046 ◽  
Author(s):  
Youren Tong ◽  
Jie Shen

Mutations in LRRK2 (leucine-rich repeat kinase 2) are the most common genetic cause of PD (Parkinson's disease). To investigate how mutations in LRRK2 cause PD, we generated LRRK2 mutant mice either lacking its expression or expressing the R1441C mutant form. Homozygous R1441C knockin mice exhibit no dopaminergic neurodegeneration or alterations in steady-state levels of striatal dopamine, but they show impaired dopamine neurotransmission, as was evident from reductions in amphetamine-induced locomotor activity and stimulated catecholamine release in cultured chromaffin cells as well as impaired dopamine D2 receptor-mediated functions. Whereas LRRK2−/− brains are normal, LRRK2−/− kidneys at 20 months of age develop striking accumulation and aggregation of α-synuclein and ubiquitinated proteins, impairment of the autophagy–lysosomal pathway, and increases in apoptotic cell death, inflammatory responses and oxidative damage. Our further analysis of LRRK2−/− kidneys at multiple ages revealed unique age-dependent biphasic alterations of the autophagic activity, which is unchanged at 1 month of age, enhanced at 7 months, but reduced at 20 months. Levels of α-synuclein and protein carbonyls, a general oxidative damage marker, are also decreased in LRRK2−/− kidneys at 7 months of age. Interestingly, this biphasic alteration is associated with increased levels of lysosomal proteins and proteases as well as progressive accumulation of autolysosomes and lipofuscin granules. We conclude that pathogenic mutations in LRRK2 impair the nigrostriatal dopaminergic pathway, and LRRK2 plays an essential role in the dynamic regulation of autophagy function in vivo.

2020 ◽  
Author(s):  
dewei he ◽  
dianfeng liu ◽  
ang zhou ◽  
xiyu gao ◽  
yufei zhang ◽  
...  

Abstract Background Parkinson's disease (PD), the second largest neurodegenerative disease seriously affects human health. Microglia, the main immune cells in the brain participate in the innate immune response in the central nervous system (CNS). Studies have shown that microglia can be polarized into pro-inflammatory M1 and anti-inflammatory M2 phenotypes. Accumulated evidences suggest that over-activated M1 microglia release pro-inflammatory mediators that damage neurons and lead to Parkinson's disease (PD). In contrast, M2 microglia release neuroprotective factors and exert the effects of neuroprotection. Camptothecin (CPT), an extract of the plant Camptotheca acuminate, has been reported to have anti-inflammation and antitumor effects. However the effect of CPT on microglia polarization and microglia-mediated inflammation responses has not been reported. Therefore, we aim to explore the effect of CPT on microglia polarization and its underlying mechanism on neuroinflammation. Methods C57BL/6 mice (25–30 g) were injected LPS or PBS into the substantia nigra (SN). Open-Field Test and Immunohistochemistry were performed to test the dyskinesia of mice and the loss of neurons in the substantia nigra (SN). Microglia cell line BV-2, the neuroblastoma SH-SY5Y and dopaminergic neuron MN9D cell were cultured. Cytotoxicity assay, reverse transcription quantitative real-time polymerase chain reaction (RT-PCR), Western blot, ELISA and Immunofluorescence staining were performed. All results were presented with mean ± SD. Results In vivo, CPT improved dyskinesia of mice, reduced the loss of neurons in the substantia nigra (SN) and inhibited neuro-inflammatory responses in LPS-injected mice. In vitro, CPT inhibited M1 polarization of microglia and promotes M2 polarization via the AKT/Nrf2/HO-1-NF-κB signal axis. Furthermore, CPT protected the neuroblastoma cell line SH-SY5Y and dopaminergic neuron cell line MN9D from neurotoxicity of mediated by microglia activation. Conclusion CPT regulates the microglia polarization phenotype via the AKT/Nrf2/HO-1-NF-κB signal axis, inhibits neuro-inflammatory responses and exerts neuroprotective effects in vivo and in vitro.


Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5371
Author(s):  
Ying Guo ◽  
Zhizhong Ma ◽  
Xianling Ning ◽  
Ying Chen ◽  
Chao Tian ◽  
...  

A novel class of styryl sulfones were designed and synthesized as CAPE derivatives by our work team, which showed a multi-target neuroprotective effect, including antioxidative and anti-neuroinflammatory properties. However, the underlying mechanisms remain unclear. In the present study, the anti-Parkinson’s disease (PD) activity of 10 novel styryl sulfone compounds was screened by the cell viability test and the NO inhibition test in vitro. It was found that 4d exhibited the highest activity against PD among them. In a MPTP-induced mouse model of PD, the biological activity of 4d was validated through suppressing dopamine neurotoxicity, microglial activation, and astrocytes activation. With compound 4d, we conducted the mechanistic studies about anti-inflammatory responses through inhibition of p38 phosphorylation to protect dopaminergic neurons, and antioxidant effects through promoting nuclear factor erythroid 2-related factor 2 (Nrf2). The results revealed that 4d could significantly inhibit 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/1-methyl-4-phenylpyridinium (MPTP/MPP+)-induced p38 mitogen-activated protein kinase (MAPK) activation in both in vitro and in vivo PD models, thus inhibiting the NF-κB-mediated neuroinflammation-related apoptosis pathway. Simultaneously, it could promote Nrf2 nuclear transfer, and upregulate the expression of antioxidant phase II detoxification enzymes HO-1 and GCLC, and then reduce oxidative damage.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Sarah MacIsaac ◽  
Thaiany Quevedo Melo ◽  
Yuting Zhang ◽  
Mattia Volta ◽  
Matthew J Farrer ◽  
...  

Abstract Neuronal aggregates containing α-synuclein are a pathological hallmark of several degenerative diseases; including Parkinson’s disease, Parkinson’s disease with dementia and dementia with Lewy bodies. Understanding the process of α-synuclein aggregation, and discovering means of preventing it, may help guide therapeutic strategy and drug design. Recent advances provide tools to induce α-synuclein aggregation in neuronal cultures. Application of exogenous pre-formed fibrillar α-synuclein induces pathological phosphorylation and accumulation of endogenous α-synuclein, typical of that seen in disease. Genomic variability and mutations in α-synuclein and leucine-rich repeat kinase 2 proteins are the major genetic risk factors for Parkinson’s disease. Reports demonstrate fibril-induced α-synuclein aggregation is increased in cells from leucine-rich repeat kinase 2 pathogenic mutant (G2019S) overexpressing mice, and variously decreased by leucine-rich repeat kinase 2 inhibitors. Elsewhere in vivo antisense knock-down of leucine-rich repeat kinase 2 protein has been shown to protect mice from fibril-induced α-synuclein aggregation, whereas kinase inhibition did not. To help bring clarity to this issue, we took a purely genetic approach in a standardized neuron-enriched culture, lacking glia. We compared fibril treatment of leucine-rich repeat kinase 2 germ-line knock-out, and G2019S germ-line knock-in, mouse cortical neuron cultures with those from littermates. We found leucine-rich repeat kinase 2 knock-out neurons are resistant to α-synuclein aggregation, which predominantly forms within axons, and may cause axonal fragmentation. Conversely, leucine-rich repeat kinase 2 knock-in neurons are more vulnerable to fibril-induced α-synuclein accumulation. Protection and resistance correlated with basal increases in a lysosome marker in knock-out, and an autophagy marker in knock-in cultures. The data add to a growing number of studies that argue leucine-rich repeat kinase 2 silencing, and potentially kinase inhibition, may be a useful therapeutic strategy against synucleinopathy.


Author(s):  
Yinquan Fang ◽  
Qingling Jiang ◽  
Shanshan Li ◽  
Hong Zhu ◽  
Rong Xu ◽  
...  

AbstractAlthough β-arrestins (ARRBs) regulate diverse physiological and pathophysiological processes, their functions and regulation in Parkinson’s disease (PD) remain poorly defined. In this study, we show that the expression of β-arrestin 1 (ARRB1) and β-arrestin 2 (ARRB2) is reciprocally regulated in PD mouse models, particularly in microglia. ARRB1 ablation ameliorates, whereas ARRB2 knockout aggravates, the pathological features of PD, including dopaminergic neuron loss, neuroinflammation and microglia activation in vivo, and microglia-mediated neuron damage in vitro. We also demonstrate that ARRB1 and ARRB2 produce adverse effects on inflammation and activation of the inflammatory STAT1 and NF-κB pathways in primary cultures of microglia and macrophages and that two ARRBs competitively interact with the activated form of p65, a component of the NF-κB pathway. We further find that ARRB1 and ARRB2 differentially regulate the expression of nitrogen permease regulator-like 3 (Nprl3), a functionally poorly characterized protein, as revealed by RNA sequencing, and that in the gain- and loss-of-function studies, Nprl3 mediates the functions of both ARRBs in microglia inflammatory responses. Collectively, these data demonstrate that two closely related ARRBs exert opposite functions in microglia-mediated inflammation and the pathogenesis of PD which are mediated at least in part through Nprl3 and provide novel insights into the understanding of the functional divergence of ARRBs in PD.


2010 ◽  
Vol 25 (16) ◽  
pp. 2777-2784 ◽  
Author(s):  
Marta G. Vučcković ◽  
Quanzheng Li ◽  
Beth Fisher ◽  
Angelo Nacca ◽  
Richard M. Leahy ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
RenRong Wei ◽  
Jing OuYang ◽  
WeiXian Lin ◽  
TongXiang Lin

Parkinson’s disease (PD) is marked by the progressive degeneration of dopaminergic neurons (DAN) accompanied by glial activation. Thus, inhibiting glial activation that occurs during this disease could be an effective method for treating PD. Optimized Yinxieling Formula (OYF), a Chinese medicinal formula, which is used to efficiently treat autoimmune disease psoriasis, has been proved to display potential immunomodulatory effects in inflammation-associated diseases. This study assessed the therapeutic benefits of OYF on glial-mediated neuroinflammation and neuroprotection in PD models in vitro and in vivo. First, the results showed that OYF significantly suppresses LPS-induced proinflammatory cytokine secretion and attenuates the overall inflammatory responses in BV-2 cells. Second, in vivo studies confirm that while the validity of our MPTP-induced PD mouse models possesses activated glia and significant neurobehavioral dysfunction, pretreatment with OYF prevents glial activation and ameliorates movement dysfunction in the MPTP-induced PD mouse models as evaluated by the pole and rotarod tests. Third, transcriptomic analyses were carried out to reveal the underlying molecular mechanism of the OYF treatment. Sixteen pathways were significantly upregulated in the OYF-treated PD model mice, including the cytokine-cytokine receptor interaction, cell adhesion molecules, coagulation, and complement cascades. Fifteen pathways were significantly downregulated in the OYF-treated PD model mice, such as the natural killer cell mediated cytotoxicity, hematopoietic cell lineage, phagosome, and others. These pathways share direct or indirect features of immunomodulation, suggesting that the physiological effects of OYF involve key roles of immune and inflammation regulations. Therefore, we prove that OYF is a useful immunomodulatory formula in developing prevention and treatment methods for neurodegenerative disease PD.


2018 ◽  
Vol 19 (8) ◽  
pp. 2242 ◽  
Author(s):  
Dewei He ◽  
Bingxu Huang ◽  
Shoupeng Fu ◽  
Yuhang Li ◽  
Xin Ran ◽  
...  

Parkinson’s disease (PD), a frequent degenerative disease in the elderly, is characterized by dopaminergic neurodegeneration in the substantia nigra pars compacta (SNpc). Neuroinflammation caused by over-activated microglia plays a crucial role in the pathogenesis of PD. Tubeimoside I (TBMS1) has a broad anti-inflammatory effect in peripheral tissues, but the effect on neuroinflammation has not been reported. Therefore, we explored whether TBMS1 could protect dopaminergic neurons by inhibiting the activation of microglia in lipopolysaccharide (LPS)-induced PD rat model. In addition, then, the effect and mechanism of TBMS1 on neuroinflammation were assessed in LPS-exposed murine microglial BV-2 cells. The results in vivo showed that TBMS1 suppressed microglial activation and dopaminergic neurons’ reduction in LPS-injected PD rat model. In vitro study found that TBMS1 could inhibit LPS-induced inflammatory responses in BV-2 cells, and this effect was mediated by suppressing the phosphorylation of protein kinase B (AKT), nuclear factor-kappa B (NF-κB p65), p38 and extracellular regulated protein kinases (ERK1/2). Taken together, these results demonstrated for the first time that TBMS1 played a role in protecting dopaminergic neurons by inhibiting neuroinflammation mediated by microglia.


2020 ◽  
Author(s):  
dewei he ◽  
Dianfeng Liu ◽  
Ang Zhou ◽  
Xiyu Gao ◽  
Yufei Zhang ◽  
...  

Abstract Background Parkinson's disease (PD), the second largest neurodegenerative disease seriously affects human health. Microglia, the main immune cells in the brain participate in the innate immune response in the central nervous system (CNS). Studies have shown that microglia can be polarized into pro-inflammatory M1 and anti-inflammatory M2 phenotypes. Accumulated evidences suggest that over-activated M1 microglia release pro-inflammatory mediators that damage neurons and lead to Parkinson's disease (PD). In contrast, M2 microglia release neuroprotective factors and exert the effects of neuroprotection. Camptothecin (CPT), an extract of the plant Camptotheca acuminate, has been reported to have anti-inflammation and antitumor effects. However the effect of CPT on microglia polarization and microglia-mediated inflammation responses has not been reported. Therefore, we aim to explore the effect of CPT on microglia polarization and its underlying mechanism on neuroinflammation. Methods C57BL/6 mice (25–30 g) were injected LPS or PBS into the substantia nigra (SN). Open-Field Test and Immunohistochemistry were performed to test the dyskinesia of mice and the loss of neurons in the substantia nigra (SN). Microglia cell line BV-2, the neuroblastoma SH-SY5Y and dopaminergic neuron MN9D cell were cultured. Cytotoxicity assay, reverse transcription quantitative real-time polymerase chain reaction (RT-PCR), Western blot, ELISA and Immunofluorescence staining were performed. All results were presented with mean ± SD. Results In vivo, CPT improved dyskinesia of mice, reduced the loss of neurons in the substantia nigra (SN) and inhibited neuro-inflammatory responses in LPS-injected mice. In vitro, CPT inhibited M1 polarization of microglia and promotes M2 polarization via the AKT/Nrf2/HO-1-NF-κB signal axis. Furthermore, CPT protected the neuroblastoma cell line SH-SY5Y and dopaminergic neuron cell line MN9D from neurotoxicity of mediated by microglia activation. Conclusion CPT regulates the microglia polarization phenotype via the AKT/Nrf2/HO-1-NF-κB signal axis, inhibits neuro-inflammatory responses and exerts neuroprotective effects in vivo and in vitro.


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