scholarly journals Basal mitophagy is widespread in Drosophila but minimally affected by loss of Pink1 or parkin

2018 ◽  
Vol 217 (5) ◽  
pp. 1613-1622 ◽  
Author(s):  
Juliette J. Lee ◽  
Alvaro Sanchez-Martinez ◽  
Aitor Martinez Zarate ◽  
Cristiane Benincá ◽  
Ugo Mayor ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Substantial Impact ◽  
Physiological Conditions ◽  
The Impact ◽  
Dopaminergic Neuron Loss ◽  
Transgenic Drosophila

The Parkinson’s disease factors PINK1 and parkin are strongly implicated in stress-induced mitophagy in vitro, but little is known about their impact on basal mitophagy in vivo. We generated transgenic Drosophila melanogaster expressing fluorescent mitophagy reporters to evaluate the impact of Pink1/parkin mutations on basal mitophagy under physiological conditions. We find that mitophagy is readily detectable and abundant in many tissues, including Parkinson’s disease–relevant dopaminergic neurons. However, we did not detect mitolysosomes in flight muscle. Surprisingly, in Pink1 or parkin null flies, we did not observe any substantial impact on basal mitophagy. Because these flies exhibit locomotor defects and dopaminergic neuron loss, our findings raise questions about current assumptions of the pathogenic mechanism associated with the PINK1/parkin pathway. Our findings provide evidence that Pink1 and parkin are not essential for bulk basal mitophagy in Drosophila. They also emphasize that mechanisms underpinning basal mitophagy remain largely obscure.

scholarly journals Basal mitophagy is widespread in Drosophila but minimally affected by loss of Pink1 or parkin

2018 ◽  
Author(s):  
Juliette J. Lee ◽  
Alvaro Sanchez-Martinez ◽  
Aitor Martinez Zarate ◽  
Cristiane Benincá ◽  
Ugo Mayor ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Flight Muscle ◽  
Substantial Impact ◽  
Physiological Conditions ◽  
The Impact ◽  
Dopaminergic Neuron Loss

AbstractParkinson’s disease factors, PINK1 and parkin, are strongly implicated in stress-induced mitophagy in vitro, but little is known about their impact on basal mitophagy in vivo. We generated transgenic Drosophila expressing fluorescent mitophagy reporters to evaluate the impact of Pink1/parkin mutations on basal mitophagy under physiological conditions. We find that mitophagy is readily detectable and abundant in many tissues including Parkinson’s disease relevant dopaminergic neurons. However, we did not detect mitolysosomes in flight muscle. Surprisingly, in Pink1 or parkin null flies we did not observe any substantial impact on basal mitophagy. As these flies exhibit locomotor defects and dopaminergic neuron loss, our findings raise questions about current assumptions of the pathogenic mechanism associated with the PINK1/Parkin pathway. Our findings provide evidence that Pink1 and parkin are not essential for bulk basal mitophagy in Drosophila. They also emphasize that mechanisms underpinning basal mitophagy remain largely obscure.SummaryPINK1/parkin are key mediators of stress-induced mitophagy in vitro but their impact on basal mitophagy in vivo is unclear. Novel Drosophila reporters lines reveal abundant mitophagy in many tissues including dopaminergic neurons but is unaffected by loss of PINK1/parkin.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
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.

scholarly journals Loss of SATB1 Induces a p21 Dependent Cellular Senescence Phenotype in Dopaminergic Neurons

2018 ◽  
Author(s):  
Markus Riessland ◽  
Benjamin Kolisnyk ◽  
Tae Wan Kim ◽  
Jia Cheng ◽  
Jason Ni ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cellular Senescence ◽  
Dopaminergic Neurons ◽  
Dna Binding Protein ◽  
Dopamine Neurons ◽  
Human Stem Cell ◽  
Transcriptional Program

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.

scholarly journals Cav2.3 channels contribute to dopaminergic neuron loss in a model of Parkinson’s disease

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Julia Benkert ◽  
Simon Hess ◽  
Shoumik Roy ◽  
Dayne Beccano-Kelly ◽  
Nicole Wiederspohn ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Neuronal Viability ◽  
Age Dependent ◽  
Human Ipsc ◽  
Reduced Activity ◽  
Dopaminergic Neuron Loss ◽  
Full Protection

Abstract Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkinson’s disease. The mechanisms underlying this age-dependent and region-selective neurodegeneration remain unclear. Here we identify Cav2.3 channels as regulators of nigral neuronal viability. Cav2.3 transcripts were more abundant than other voltage-gated Ca2+ channels in mouse nigral neurons and upregulated during aging. Plasmalemmal Cav2.3 protein was higher than in dopaminergic neurons of the ventral tegmental area, which do not degenerate in Parkinson’s disease. Cav2.3 knockout reduced activity-associated nigral somatic Ca2+ signals and Ca2+-dependent after-hyperpolarizations, and afforded full protection from degeneration in vivo in a neurotoxin Parkinson’s mouse model. Cav2.3 deficiency upregulated transcripts for NCS-1, a Ca2+-binding protein implicated in neuroprotection. Conversely, NCS-1 knockout exacerbated nigral neurodegeneration and downregulated Cav2.3. Moreover, NCS-1 levels were reduced in a human iPSC-model of familial Parkinson’s. Thus, Cav2.3 and NCS-1 may constitute potential therapeutic targets for combatting Ca2+-dependent neurodegeneration in Parkinson’s disease.

AAV.shRNA-mediated downregulation of ROCK2 attenuates degeneration of dopaminergic neurons in toxin-induced models of Parkinson's disease in vitro and in vivo

2015 ◽  
Vol 73 ◽  
pp. 150-162 ◽  
Author(s):  
Kim-Ann Saal ◽  
Jan C. Koch ◽  
Lars Tatenhorst ◽  
Éva M. Szegő ◽  
Vinicius Toledo Ribas ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons

scholarly journals Postmortem studies in Parkinson's disease

2004 ◽  
Vol 6 (3) ◽  
pp. 281-293 ◽  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Gold Standard ◽  
Dopaminergic Neurons ◽  
Nigrostriatal System ◽  
Regional Vulnerability ◽  
Environmental Agents ◽  
Postmortem Studies

No animal model to date perfectly replicates Parkinson's disease (PD) etiopathogenesis, and the anatomical organization of the nigrostriatal system differs considerably between species. Human postmortem material therefore remains the gold standard for both formulating hypotheses for subsequent testing in in vitro and in vivo PD models and verifying hypotheses derived from experimental PD models with regard to their validity in the human disease. This article focuses on recent and relevant fields in which human postmortem work has generated significant impact in our understanding of PD. These fields include Lewy body formation, regional vulnerability of dopaminergic neurons, oxidative/nitrative cellular stress, inflammation, apoptosis, infectious and environmental agents, and nondopaminergic lesions.

scholarly journals Identification of Targets from LRRK2 Rescue Phenotypes

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 76
Author(s):  
Joanne Toh ◽  
Ling Ling Chua ◽  
Patrick Ho ◽  
Edwin Sandanaraj ◽  
Carol Tang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Rna Sequencing ◽  
Dopaminergic Neurons ◽  
Pathway Enrichment Analysis ◽  
Specific Gene ◽  
Neuroprotective Effects ◽  
Transgenic Drosophila ◽  
Protective Variants

Parkinson’s disease (PD) is an age-dependent neurodegenerative condition. Leucine-rich repeat kinase 2 (LRRK2) mutations are the most frequent cause of sporadic and autosomal dominant PD. The exact role of LRRK2 protective variants (R1398H, N551K) together with a pathogenic mutant (G2019S) in aging and neurodegeneration is unknown. We generated the following myc-tagged UAS-LRRK2 transgenic Drosophila: LRRK2 (WT), N551K, R1398H, G2019S single allele, and double-mutants (N551K/G2019S or R1398H/G2019S). The protective variants alone were able to suppress the phenotypic effects caused by the pathogenic LRRK2 mutation. Next, we conducted RNA-sequencing using mRNA isolated from dopaminergic neurons of these different groups of transgenic Drosophila. Using pathway enrichment analysis, we identified the top 10 modules (p < 0.05), with “LRRK2 in neurons in Parkinson’s disease” among the candidates. Further dissection of this pathway identified the most significantly modulated gene nodes such as eEF1A2, ACTB, eEF1A, and actin cytoskeleton reorganization. The induction of the pathway was successfully restored by the R1398H protective variant and R1398H-G2019S or N551K-G2019S rescue experiments. The oxidoreductase family of genes was also active in the pathogenic mutant and restored in protective and rescue variants. In summary, we provide in vivo evidence supporting the neuroprotective effects of LRRK2 variants. RNA sequencing of dopaminergic neurons identified upregulation of specific gene pathways in the Drosophila carrying the pathogenic variant, and this was restored in the rescue phenotypes. Using protective gene variants, our study identifies potential new targets and provides proof of principle of a new therapeutic approach that will further our understanding of aging and neurodegeneration in PD.

The differences between high and low-dose administration of VEGF to dopaminergic neurons of in vitro and in vivo Parkinson's disease model

2005 ◽  
Vol 1038 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Takao Yasuhara ◽  
Tetsuro Shingo ◽  
Kenichiro Muraoka ◽  
Yuan wen ji ◽  
Masahiro Kameda ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Low Dose ◽  
Disease Model ◽  
Dose Administration

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 ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Human Genetics ◽  
Neurodegenerative Disorder ◽  
Inflammatory Factors ◽  
Inflammatory Mechanism

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.

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