scholarly journals α-Synuclein E46K Mutation and Involvement of Oxidative Stress in a Drosophila Model of Parkinson’s Disease

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Samaneh Reiszadeh Jahromi ◽  
S. R. Ramesh ◽  
David I. Finkelstein ◽  
Mohammad Haddadi

Parkinson’s disease (PD) is an age-associated neurodegenerative condition in which some genetic variants are known to increase disease susceptibility on interaction with environmental factors inducing oxidative stress. Different mutations in the SNCA gene are reported as the major genetic contributors to PD. E46K mutation pathogenicity has not been investigated as intensive as other SNCA gene mutations including A30P and A53T. In this study, based on the GAL4-UAS binary genetic tool, transgenic Drosophila melanogaster flies expressing wild-type and E46K-mutated copies of the human SNCA gene were constructed. Western blotting, immunohistochemical analysis, and light and confocal microscopy of flies’ brains were undertaken along with the survival rate measurement, locomotor function assay, and ethanol and paraquat (PQ) tolerance to study α-synuclein neurotoxicity. Biochemical bioassays were carried out to investigate the activity of antioxidant enzymes and alterations in levels of oxidative markers following damages induced by human α-synuclein to the neurons of the transgenic flies. Overexpression of human α-synuclein in the central nervous system of these transgenic flies led to disorganized ommatidia structures and loss of dopaminergic neurons. E46K α-synuclein caused remarkable climbing defects, reduced survivorship, higher ethanol sensitivity, and increased PQ-mediated mortality. A noticeable decline in activity of catalase and superoxide dismutase enzymes besides considerable increase in the levels of lipid peroxidation and reactive oxygen species was observed in head capsule homogenates of α-synuclein-expressing flies, which indicates obvious involvement of oxidative stress as a causal factor in SNCAE46K neurotoxicity. In all the investigations, E46K copy of the SNCA gene was found to impose more severe defects when compared to wild-type SNCA. It can be concluded that the constructed Drosophila models developed PD-like symptoms that facilitate comparative studies of molecular and cellular pathways implicated in the pathogenicity of different α-synuclein mutations.

2020 ◽  
Author(s):  
Samaneh Reiszadeh Jahromi ◽  
S R Ramesh ◽  
David I Finkelstein ◽  
Mohammad Haddadi

AbstractParkinson’s disease (PD) is a class of neurodegenerative disorders in which, complex interactions of genetic and environmental agents are involved in the etiology of both sporadic and familial PD cases. α-synuclein-encoding SNCA gene is known as one of the major genetic contributors of this disease. E46K mutation in SNCA gene has not been investigated as intensive as other SNCA gene mutations including A30P and A53T. In this study, to induce PD in Drosophila flies, UAS-hSNCAWT and UAS-hSNCAE46K transgenic fly lines were constructed, where SNCA gene was over-expressed in flies brains using GAL4-UAS genetic system. Western blot analysis of head samples of SNCA-expressing flies verified SNCA expression at protein level. Light and electron microscopy analysis of ommatidial structures were performed to verify neurodegeneration as a result of α-synuclein gene overexpression in Drosophila transgenic flies. Confocal microscopy analysis of dopaminergic neuron clusters verified cell loss following SNCAE46K expression in the flies’ brain. E46K α-synuclein gene over-expression resulted in an evident decline in longevity as well as climbing ability of the flies. Biochemical studies of transgenic flies showed a remarkable decline in antioxidant enzymes activity and a significant increase in oxidative markers level as well as AchE enzyme activity. Oxidative stress has been known as a causal factor in PD pathogenesis, following expression of E46K mutant version of human SNCA gene. This Drosophila model is able to facilitate comparative studies of both molecular and cellular assays implicated in the assessment of neurotoxicity of different α-synuclein mutations.


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 928
Author(s):  
Jung Hwa Seo ◽  
Seong-Woong Kang ◽  
Kyungri Kim ◽  
Soohyun Wi ◽  
Jang Woo Lee ◽  
...  

Although environmental enrichment (EE) is known to reduce oxidative stress in Parkinson’s disease (PD), the metabolic alternations for detoxifying endogenous and xenobiotic compounds according to various brain regions are not fully elucidated yet. This study aimed to further understand the role of EE on detoxifying enzymes, especially those participating in phase I of metabolism, by investigating the levels of enzymes in various brain regions such as the olfactory bulb, brain stem, frontal cortex, and striatum. Eight-month-old transgenic PD mice with the overexpression of human A53T α-synuclein and wild-type mice were randomly allocated to either standard cage condition or EE for 2 months. At 10 months of age, the expression of detoxifying enzymes was evaluated and compared with wild-type of the same age raised in standard cages. EE improved neurobehavioral outcomes such as olfactory and motor function in PD mice. EE-treated mice showed that oxidative stress was attenuated in the olfactory bulb, brain stem, and frontal cortex. EE also reduced apoptosis and induced cell proliferation in the subventricular zone of PD mice. The overexpression of detoxifying enzymes was observed in the olfactory bulb and brain stem of PD mice, which was ameliorated by EE. These findings were not apparent in the other experimental regions. These results suggest the stage of PD pathogenesis may differ according to brain region, and that EE has a protective effect on the PD pathogenesis by decreasing oxidative stress.


2021 ◽  
Author(s):  
Vaibhavi Peshattiwar ◽  
Suraj Muke ◽  
Aakruti Kaikini ◽  
Sneha Bagle ◽  
Vikas Dighe ◽  
...  

Abstract Parkinson’s disease (PD) ranks as second most prevalent neurodegenerative disorder but is devoid of neuroprotective treatment. Approaches with disease modifying ability with symptomatic relief has become an utmost necessity. Further multifactorial nature of PD presents challenges for efficacy evaluation of any potential test compound. The stated study makes an attempt to address these issues by employing a rotenone induced PD model involving a bilateral intranigral stereotactic rotenone injection for evaluation of the neuroprotective efficacy of Daidzein (DZ). DZ a soy isoflavone, is known for its various health benefits viz. immunomodulation, cardiovascular effects etc. In this study, animals after intranigral rotenone (12 μg) injection, were treated with DZ at a dose of 5, 10 and 20 mg/kg for 30 days. The neurobehavioural evaluation comprised of Rota-rod, Open field and Barnes maze test. The biochemical analysis constituting oxidative stress (Reduced glutathione, superoxide dismutase, catalase and lipid peroxidation), inflammation (TNF-α), mitochondrial alteration (complex I activity and biogenesis) was conducted on mid-brain tissue after 30 days of treatment. The SN and striatum was also subjected to immunohistochemical analysis (IHC) for TH positive neurons and Glial Fibrillary Acidic Protein. The analysis revealed significant improvement by daidzein in motor co-ordination and attenuation in cognitive deficits due to rotenone. The biochemical assessment exhibited significant decrement in oxidative stress as well as inflammation. DZ treatment also prevented complex I inhibition and promoted mitochondrial biogenesis eventually contributing to the neuroprotection apparent in IHC. Thus, the results strongly corroborate the neuroprotective potential of DZ against rotenone induced model of PD.


2009 ◽  
Vol 109 (3) ◽  
pp. 463-468 ◽  
Author(s):  
Takashi Yanagida ◽  
Yoshihisa Kitamura ◽  
Koichiro Yamane ◽  
Kazunori Takahashi ◽  
Kazuyuki Takata ◽  
...  

2012 ◽  
Vol 11 (4) ◽  
pp. 430-438 ◽  
Author(s):  
Marcella Reale ◽  
Mirko Pesce ◽  
Medha Priyadarshini ◽  
Mohammad A Kamal ◽  
Antonia Patruno

2021 ◽  
Vol 22 (9) ◽  
pp. 4676
Author(s):  
Katja Badanjak ◽  
Sonja Fixemer ◽  
Semra Smajić ◽  
Alexander Skupin ◽  
Anne Grünewald

With the world’s population ageing, the incidence of Parkinson’s disease (PD) is on the rise. In recent years, inflammatory processes have emerged as prominent contributors to the pathology of PD. There is great evidence that microglia have a significant neuroprotective role, and that impaired and over activated microglial phenotypes are present in brains of PD patients. Thereby, PD progression is potentially driven by a vicious cycle between dying neurons and microglia through the instigation of oxidative stress, mitophagy and autophagy dysfunctions, a-synuclein accumulation, and pro-inflammatory cytokine release. Hence, investigating the involvement of microglia is of great importance for future research and treatment of PD. The purpose of this review is to highlight recent findings concerning the microglia-neuronal interplay in PD with a focus on human postmortem immunohistochemistry and single-cell studies, their relation to animal and iPSC-derived models, newly emerging technologies, and the resulting potential of new anti-inflammatory therapies for PD.


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