scholarly journals Mitochondrial alpha-synuclein accumulation impairs complex I function in dopaminergic neurons and results in increased mitophagy in vivo

2010 ◽  
Vol 486 (3) ◽  
pp. 235-239 ◽  
Author(s):  
Shankar J. Chinta ◽  
Jyothi K. Mallajosyula ◽  
Anand Rane ◽  
Julie K. Andersen
Keyword(s):  
Dopaminergic Neurons ◽  
Complex I ◽  
Alpha Synuclein

scholarly journals The C-Terminal Domain of LRRK2 with the G2019S Substitution Increases Mutant A53T α-Synuclein Toxicity in Dopaminergic Neurons In Vivo

2021 ◽  
Vol 22 (13) ◽  
pp. 6760
Author(s):  
Noémie Cresto ◽  
Camille Gardier ◽  
Marie-Claude Gaillard ◽  
Francesco Gubinelli ◽  
Pauline Roost ◽  
...  
Keyword(s):  
Dopaminergic Neurons ◽  
Alpha Synuclein ◽  
Post Injection ◽  
Terminal Portion ◽  
Contrast Injection ◽  
Neuron Degeneration ◽  
Terminal Domain ◽  
G2019s Mutation ◽  
A53t Mutation

Alpha-synuclein (α-syn) and leucine-rich repeat kinase 2 (LRRK2) play crucial roles in Parkinson’s disease (PD). They may functionally interact to induce the degeneration of dopaminergic (DA) neurons via mechanisms that are not yet fully understood. We previously showed that the C-terminal portion of LRRK2 (ΔLRRK2) with the G2019S mutation (ΔLRRK2G2019S) was sufficient to induce neurodegeneration of DA neurons in vivo, suggesting that mutated LRRK2 induces neurotoxicity through mechanisms that are (i) independent of the N-terminal domains and (ii) “cell-autonomous”. Here, we explored whether ΔLRRK2G2019S could modify α-syn toxicity through these two mechanisms. We used a co-transduction approach in rats with AAV vectors encoding ΔLRRK2G2019S or its “dead” kinase form, ΔLRRK2DK, and human α-syn with the A53T mutation (AAV-α-synA53T). Behavioral and histological evaluations were performed at 6- and 15-weeks post-injection. Results showed that neither form of ΔLRRK2 alone induced the degeneration of neurons at these post-injection time points. By contrast, injection of AAV-α-synA53T alone resulted in motor signs and degeneration of DA neurons. Co-injection of AAV-α-synA53T with AAV-ΔLRRK2G2019S induced DA neuron degeneration that was significantly higher than that induced by AAV-α-synA53T alone or with AAV-ΔLRRK2DK. Thus, mutated α-syn neurotoxicity can be enhanced by the C-terminal domain of LRRK2G2019 alone, through cell-autonomous mechanisms.

Aplp1 and the Aplp1-Lag3 Complex facilitates transmission of pathologic alpha-synuclein

2021 ◽  
Author(s):  
Xiaobo Mao ◽  
Hao Gu ◽  
Donghoon Kim ◽  
Yasuyoshi Kimura ◽  
Ning Wang ◽  
...  
Keyword(s):  
Parkinson Disease ◽  
Molecular Mechanism ◽  
Amyloid Beta ◽  
Dopaminergic Neurons ◽  
Lymphocyte Activation ◽  
Alpha Synuclein ◽  
Therapeutic Strategies ◽  
Behavioral Deficits ◽  
Lymphocyte Activation Gene

Pathologic alpha-synuclein (alpha-syn) spreads from cell-to-cell, in part, through binding to the lymphocyte-activation gene 3 (Lag3). Here we report that amyloid beta precursor-like protein 1 (Aplp1) forms a complex with Lag3 that facilitates the binding, internalization, transmission, and toxicity of pathologic alpha-syn. Deletion of both Aplp1 and Lag3 eliminates the loss of dopaminergic neurons and the accompanying behavioral deficits induced by alpha-syn preformed fibrils (PFF). Anti-Lag3 prevents the internalization of alpha-syn PFF by disrupting the interaction of Aplp1 and Lag3, and blocks the neurodegeneration induced by alpha-syn PFF in vivo. The identification of Aplp1 and the interplay with Lag3 for alpha-syn PFF induced pathology advances our understanding of the molecular mechanism of cell-to-cell transmission of pathologic alpha-syn and provides additional targets for therapeutic strategies aimed at preventing neurodegeneration in Parkinson disease and related alpha-synucleinopathies.

scholarly journals RIT2 reduces LRRK2 kinase activity and protects against alpha-synuclein neuropathology

2020 ◽  
Author(s):  
Julia Obergasteiger ◽  
Anne-Marie Castonguay ◽  
Giulia Frapporti ◽  
Evy Lobbestael ◽  
Veerle Baekelandt ◽  
...  
Keyword(s):  
Risk Factor ◽  
Substantia Nigra ◽  
Dopaminergic Neurons ◽  
Kinase Activity ◽  
Alpha Synuclein ◽  
The Novel ◽  
Lrrk2 Kinase ◽  
Novel Strategy ◽  
Lrrk2 Kinase Activity

AbstractIn Parkinson’s disease (PD) misfolded alpha-synuclein (aSyn) accumulates in the substantia nigra, where dopaminergic neurons are progressively lost. The mechanisms underlying aSyn pathology are still unclear but hypothesized to involve the autophagy lysosome pathways (ALP). LRRK2 mutations are a major cause of familial and sporadic PD, hyperactivate kinase activity and its pharmacological inhibition reduces pS129-aSyn inclusions. We observed selective downregulation of the novel PD risk factor RIT2 in G2019S-LRRK2 expressing cells. Here we studied whether RIT2 could modulate LRRK2 kinase activity. RIT2 overexpression in G2019S-LRRK2 cells rescued ALP abnormalities and diminished aSyn inclusions. In vivo, viral mediated overexpression of RIT2 operated neuroprotection against AAV-A53T-aSyn. Furthermore, RIT2 overexpression prevented the A53T-aSyn-dependent increase of LRRK2 kinase activity in vivo. Our data indicate that RIT2 inhibits overactive LRRK2 to ameliorate ALP impairment and counteract aSyn aggregation and related deficits. Targeting RIT2 could represent a novel strategy to combat neuropathology in familial and idiopathic PD.

scholarly journals The Parkinson's Disease-Related Protein DJ-1 Protects Dopaminergic Neurons in vivo and Cultured Cells from Alpha-Synuclein and 6-Hydroxydopamine Toxicity

2014 ◽  
Vol 15 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Sara Batelli ◽  
Roberto William Invernizzi ◽  
Alessandro Negro ◽  
Eleonora Calcagno ◽  
Serena Rodilossi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Cultured Cells ◽  
Alpha Synuclein ◽  
Related Protein ◽  
6 Hydroxydopamine

scholarly journals Alpha-Synuclein Cell-to-Cell Transfer and Seeding in Grafted Dopaminergic Neurons In Vivo

PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e39465 ◽  
Author(s):  
Elodie Angot ◽  
Jennifer A. Steiner ◽  
Carla M. Lema Tomé ◽  
Peter Ekström ◽  
Bengt Mattsson ◽  
...  
Keyword(s):  
Dopaminergic Neurons ◽  
Alpha Synuclein ◽  
Cell Transfer ◽  
Cell To Cell Transfer

scholarly journals Mitochondrial complex I abnormalities is associated with tau and clinical symptoms in mild Alzheimer’s disease

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Tatsuhiro Terada ◽  
Joseph Therriault ◽  
Min Su Peter Kang ◽  
Melissa Savard ◽  
Tharick Ali Pascoal ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mitochondrial Dysfunction ◽  
Complex I ◽  
Clinical Symptoms ◽  
Mitochondrial Complex I ◽  
Braak Stage ◽  
Mitochondrial Complex ◽  
Temporal Area

Abstract Background Mitochondrial electron transport chain abnormalities have been reported in postmortem pathological specimens of Alzheimer’s disease (AD). However, it remains unclear how amyloid and tau are associated with mitochondrial dysfunction in vivo. The purpose of this study is to assess the local relationships between mitochondrial dysfunction and AD pathophysiology in mild AD using the novel mitochondrial complex I PET imaging agent [18F]BCPP-EF. Methods Thirty-two amyloid and tau positive mild stage AD dementia patients (mean age ± SD: 71.1 ± 8.3 years) underwent a series of PET measurements with [18F]BCPP-EF mitochondrial function, [11C]PBB3 for tau deposition, and [11C] PiB for amyloid deposition. Age-matched normal control subjects were also recruited. Inter and intrasubject comparisons of levels of mitochondrial complex I activity, amyloid and tau deposition were performed. Results The [18F]BCPP-EF uptake was significantly lower in the medial temporal area, highlighting the importance of the mitochondrial involvement in AD pathology. [11C]PBB3 uptake was greater in the temporo-parietal regions in AD. Region of interest analysis in the Braak stage I-II region showed significant negative correlation between [18F]BCPP-EF SUVR and [11C]PBB3 BPND (R = 0.2679, p = 0.04), but not [11C] PiB SUVR. Conclusions Our results indicated that mitochondrial complex I is closely associated with tau load evaluated by [11C]PBB3, which might suffer in the presence of its off-target binding. The absence of association between mitochondrial complex I dysfunction with amyloid load suggests that mitochondrial dysfunction in the trans-entorhinal and entorhinal region is a reflection of neuronal injury occurring in the brain of mild AD.

scholarly journals Multiple system atrophy-associated oligodendroglial protein p25α stimulates formation of novel α-synuclein strain with enhanced neurodegenerative potential

2021 ◽  
Author(s):  
Nelson Ferreira ◽  
Hjalte Gram ◽  
Zachary A. Sorrentino ◽  
Emil Gregersen ◽  
Sissel Ida Schmidt ◽  
...  
Keyword(s):  
Multiple System Atrophy ◽  
Protein Misfolding ◽  
Resonance Energy Transfer ◽  
Lewy Bodies ◽  
Resonance Energy ◽  
Alpha Synuclein ◽  
Striatal Neurons ◽  
End Stage ◽  
Intracellular Aggregates

AbstractPathology consisting of intracellular aggregates of alpha-Synuclein (α-Syn) spread through the nervous system in a variety of neurodegenerative disorders including Parkinson’s disease, dementia with Lewy bodies, and multiple system atrophy. The discovery of structurally distinct α-Syn polymorphs, so-called strains, supports a hypothesis where strain-specific structures are templated into aggregates formed by native α-Syn. These distinct strains are hypothesised to dictate the spreading of pathology in the tissue and the cellular impact of the aggregates, thereby contributing to the variety of clinical phenotypes. Here, we present evidence of a novel α-Syn strain induced by the multiple system atrophy-associated oligodendroglial protein p25α. Using an array of biophysical, biochemical, cellular, and in vivo analyses, we demonstrate that compared to α-Syn alone, a substoichiometric concentration of p25α redirects α-Syn aggregation into a unique α-Syn/p25α strain with a different structure and enhanced in vivo prodegenerative properties. The α-Syn/p25α strain induced larger inclusions in human dopaminergic neurons. In vivo, intramuscular injection of preformed fibrils (PFF) of the α-Syn/p25α strain compared to α-Syn PFF resulted in a shortened life span and a distinct anatomical distribution of inclusion pathology in the brain of a human A53T transgenic (line M83) mouse. Investigation of α-Syn aggregates in brain stem extracts of end-stage mice demonstrated that the more aggressive phenotype of the α-Syn/p25α strain was associated with an increased load of α-Syn aggregates based on a Förster resonance energy transfer immunoassay and a reduced α-Syn aggregate seeding activity based on a protein misfolding cyclic amplification assay. When injected unilaterally into the striata of wild-type mice, the α-Syn/p25α strain resulted in a more-pronounced motoric phenotype than α-Syn PFF and exhibited a “tropism” for nigro-striatal neurons compared to α-Syn PFF. Overall, our data support a hypothesis whereby oligodendroglial p25α is responsible for generating a highly prodegenerative α-Syn strain in multiple system atrophy.

scholarly journals Generation of Alpha-Synuclein Preformed Fibrils from Monomers and Use In Vivo

10.3791/59758 ◽  
2019 ◽  
Author(s):  
Joseph R. Patterson ◽  
Nicole K. Polinski ◽  
Megan F. Duffy ◽  
Christopher J. Kemp ◽  
Kelvin C. Luk ◽  
...  
Keyword(s):  
Alpha Synuclein

scholarly journals Structural basis for a complex I mutation that blocks pathological ROS production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhan Yin ◽  
Nils Burger ◽  
Duvaraka Kula-Alwar ◽  
Dunja Aksentijević ◽  
Hannah R. Bridges ◽  
...  
Keyword(s):  
Point Mutation ◽  
Complex I ◽  
Structural Changes ◽  
Ischemia Reperfusion ◽  
Single Point ◽  
Structural Basis ◽  
Single Point Mutation ◽  
Ros Production

AbstractMitochondrial complex I is central to the pathological reactive oxygen species (ROS) production that underlies cardiac ischemia–reperfusion (IR) injury. ND6-P25L mice are homoplasmic for a disease-causing mtDNA point mutation encoding the P25L substitution in the ND6 subunit of complex I. The cryo-EM structure of ND6-P25L complex I revealed subtle structural changes that facilitate rapid conversion to the “deactive” state, usually formed only after prolonged inactivity. Despite its tendency to adopt the “deactive” state, the mutant complex is fully active for NADH oxidation, but cannot generate ROS by reverse electron transfer (RET). ND6-P25L mitochondria function normally, except for their lack of RET ROS production, and ND6-P25L mice are protected against cardiac IR injury in vivo. Thus, this single point mutation in complex I, which does not affect oxidative phosphorylation but renders the complex unable to catalyse RET, demonstrates the pathological role of ROS production by RET during IR injury.

Sign in / Sign up

Export Citation Format

Share Document