Search results for "arki"
showing 10 items of 1015 documents
Contribution of cholesterol and oxysterols to the pathophysiology of Parkinson's disease
2016
International audience; Neurodegenerative diseases are a major public health issue worldwide. Some countries, including France, have engaged in research into the causes of Parkinson's disease, Alzheimer's disease, and multiple sclerosis and the management of these patients. It should lead to a better understanding of the mechanisms leading to these diseases including the possible involvement of lipids in their pathogenesis. Parkinson's disease is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra and the accumulation of α-synuclein (Lewy bodies). Several in vivo studies have shown a relationship between the lipid profile [chole…
Human R1441C LRRK2 regulates the synaptic vesicle proteome and phosphoproteome in a Drosophila model of Parkinson's disease
2016
International audience; Mutations in leucine-rich repeat kinase 2 (LRRK2) cause late-onset, autosomal dominant familial Parkinsons disease (PD) and variation at the LRRK2 locus contributes to the risk for idiopathic PD. LRRK2 can function as a protein kinase and mutations lead to increased kinase activity. To elucidate the pathophysiological mechanism of the R1441C mutation in the GTPase domain of LRRK2, we expressed human wild-type or R1441C LRRK2 in dopaminergic neurons of Drosophila and observe reduced locomotor activity, impaired survival and an age-dependent degeneration of dopaminergic neurons thereby creating a new PD-like model. To explore the function of LRRK2 variants in vivo, we …
Oxidative modification impairs SERCA activity in Drosophila and human cell models of Parkinson's disease
2021
DJ-1 is a causative gene for familial Parkinson's disease (PD) with different functions, standing out its role against oxidative stress (OS). Accordingly, PD model flies harboring a mutation in the DJ-1β gene (the Drosophila ortholog of human DJ-1) show high levels of OS markers like protein carbonylation, a common post-translational modification that may alter protein function. To increase our understanding of PD pathogenesis as well as to discover potential therapeutic targets for pharmacological intervention, we performed a redox proteomic assay in DJ-1β mutant flies. Among the proteins that showed increased carbonylation levels in PD model flies, we found SERCA, an endoplasmic reticulum…
Pressure effects on α-synuclein amyloid fibrils: An experimental investigation on their dissociation and reversible nature
2017
αâsynuclein amyloid fibrils are found in surviving neurons of Parkinson's disease affected patients, but the role they play in the disease development is still under debate. A growing number of evidences points to soluble oligomers as the major cytotoxic species, while insoluble fibrillar aggregates could even play a protection role. In this work, we investigate αâsynuclein fibrils dissociation induced at high pressure by means of Small Angle X-ray Scattering and Fourier Transform Infrared Spectroscopy. Fibrils were produced from wild type αâsynuclein and two familial mutants, A30P and A53T. Our results enlighten the different reversible nature of αâsynuclein fibrils fragmentati…
Retinal Thickness and Microvascular Pattern in Early Parkinson's Disease.
2020
A thinning of intraretinal layers has been previously described in Parkinson's disease (PD) patients compared to healthy controls (HCs). Few studies evaluated the possible correlation between retinal thickness and retinal microvascularization. Thus, here we assessed the thickness of retinal layers and microvascular pattern in early PD patients and HCs, using, respectively, spectral-domain optical coherence tomography (SD-OCT) and SD-OCT-angiography (SD-OCT-A), and more interestingly, we evaluated a possible correlation between retinal thickness and microvascular pattern. Patients fulfilling criteria for clinically established/clinically probable PD and HCs were enrolled. Exclusion criteria …
The nucleic acid-binding protein PcCNBP is transcriptionally regulated during the immune response in red swamp crayfish Procambarus clarkii
2016
Gene family encoding cellular nucleic acid binding proteins (CNBP) is well conserved among vertebrates; however, there is limited knowledge in lower organisms. In this study, a CNBP homolog from the red swamp crayfish Procambarus clarkii was characterised. The full-length cDNA of PcCNBP was of 1257 bp with a 5′-untranslated region (UTR) of 63 bp and a 3′-UTR of 331 bp with a poly (A) tail, and an open-reading frame (ORF) of 864 bp encoding a polypeptide of 287 amino acids with the predicted molecular weight of about 33 kDa. The predicted protein possesses 7 tandem repeats of 14 amino acids containing the CCHC zinc finger consensus sequence, two RGG-rich single-stranded RNA-binding domain an…
Hypothesis: Etiologic and Molecular Mechanistic Leads for Sporadic Neurodegenerative Diseases Based on Experience With Western Pacific ALS/PDC
2019
Seventy years of research on Western Pacific amyotrophic lateral sclerosis and Parkinsonism-dementia Complex (ALS/PDC) have provided invaluable data on the etiology, molecular pathogenesis and latency of this disappearing, largely environmental neurodegenerative disease. ALS/PDC is linked to genotoxic chemicals (notably methylazoxymethanol, MAM) derived from seed of the cycad plant (Cycas spp.) that were used as a traditional food and/or medicine in all three disease-affected Western Pacific populations. MAM, nitrosamines and hydrazines generate methyl free radicals that damage DNA (in the form of O6-methylguanine lesions) that can induce mutations in cycling cells and degenerative changes …
Functions and Therapeutic Potential of Extracellular Hsp60, Hsp70, and Hsp90 in Neuroinflammatory Disorders
2021
Neuroinflammation is implicated in central nervous system (CNS) diseases, but the molecular mechanisms involved are poorly understood. Progress may be accelerated by developing a comprehensive view of the pathogenesis of CNS disorders, including the immune and the chaperone systems (IS and CS). The latter consists of the molecular chaperones; cochaperones; and chaperone cofactors, interactors, and receptors of an organism and its main collaborators in maintaining protein homeostasis (canonical function) are the ubiquitin–proteasome system and chaperone-mediated autophagy. The CS has also noncanonical functions, for instance, modulation of the IS with induction of proinflammatory cytokines. …
Selective α-synuclein knockdown in monoamine neurons by intranasal oligonucleotide delivery: potential therapy for parkinson’s disease
2018
Progressive neuronal death in brainstem nuclei and widespread accumulation of α-synuclein are neuropathological hallmarks of Parkinson’s disease (PD). Reduction of α-synuclein levels is therefore a potential therapy for PD. However, because α-synuclein is essential for neuronal development and function, α-synuclein elimination would dramatically impact brain function. We previously developed conjugated small interfering RNA (siRNA) sequences that selectively target serotonin (5-HT) or norepinephrine (NE) neurons after intranasal administration. Here, we used this strategy to conjugate inhibitory oligonucleotides, siRNA and antisense oligonucleotide (ASO), with the triple monoamine reuptake …
Mitochondrial Dysfunction, Oxidative Stress and Neuroinflammation in Neurodegeneration with Brain Iron Accumulation (NBIA)
2020
The syndromes of neurodegeneration with brain iron accumulation (NBIA) encompass a group of invalidating and progressive rare diseases that share the abnormal accumulation of iron in the basal ganglia. The onset of NBIA disorders ranges from infancy to adulthood. Main clinical signs are related to extrapyramidal features (dystonia, parkinsonism and choreoathetosis), and neuropsychiatric abnormalities. Ten NBIA forms are widely accepted to be caused by mutations in the genes PANK2, PLA2G6, WDR45, C19ORF12, FA2H, ATP13A2, COASY, FTL1, CP, and DCAF17. Nonetheless, many patients remain without a conclusive genetic diagnosis, which shows that there must be additional as yet undiscovered NBIA gen…