scholarly journals The novel Parkinson's disease linked mutation G51D attenuates in vitro aggregation and membrane binding of  -synuclein, and enhances its secretion and nuclear localization in cells

2014 ◽  
Vol 23 (17) ◽  
pp. 4491-4509 ◽  
Author(s):  
M.-B. Fares ◽  
N. Ait-Bouziad ◽  
I. Dikiy ◽  
M. K. Mbefo ◽  
A. Jovi i  ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Nuclear Localization ◽  
Membrane Binding ◽  
The Novel ◽  
In Cells

scholarly journals Catalysis of ubiquitin transfer by the RBR ubiquitin ligase parkin

2014 ◽  
Vol 70 (a1) ◽  
pp. C845-C845
Author(s):  
Jean-François Trempe ◽  
Jonathan Krett ◽  
Véronique Sauvé ◽  
Marjan Seirafi ◽  
Karl Grenier ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Ubiquitin Ligase ◽  
Intermediate Formation ◽  
Acyl Transfer ◽  
Acceptor Site ◽  
E3 Ligases ◽  
Insight Into ◽  
In Cells

Mutations in the Parkin gene are responsible for an autosomal recessive form of Parkinson's disease. The parkin protein is a RING1-In-Between-RING2 (RBR) E3 ubiquitin ligase, which functions through a two-step mechanism involving a parkin~ubiquitin thioester intermediate [1]. However, compared to other ubiquitin ligases, parkin exhibits low basal activity and requires activation both in vitro and in cells. As parkin is neuroprotective in various models of Parkinson's disease, understanding how it catalyses ubiquitin transfer will be critical. We previously reported the crystal structure of full-length parkin [2]. The structure shows parkin in an auto-inhibited state and provides insight into how it is activated. The RING0 domain occludes the ubiquitin acceptor site Cys431 in RING2 whereas a novel Repressor Element of Parkin (REP) binds RING1 and blocks its E2-binding site. Remarkably, mutations that disrupt these inhibitory interactions activate parkin both in vitro and in cells. The structure also reveals that His433 and Glu444 form a catalytic dyad adjacent to Cys431. Here, we show that His433 catalyses the acyl transfer of ubiquitin carboxy terminus from Cys431 to a target lysine side-chain amino group. Mutation of His433 does not affect UbcH7~ubiquitin discharging or thioester intermediate formation, but prevents formation of polyubiquitin chains on parkin. However, mutation of His433 does not affect significantly parkin's mitochondrial recruitment and substrate ubiquitination, suggesting that other factors might be at play in vivo. We also investigate the catalytic role of other residues located around the Cys431, such as Trp462. The work provides insight into the mechanism of ubiquitination by RBR E3 ligases with important implications for Parkinson's disease.

Design, Optimization and Evaluation of Fast-Dissolving Oral Films of Ropinirole

2018 ◽  
Vol 11 (1) ◽  
pp. 3958-3967
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Srinivas A
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Good Alternative ◽  
In Vitro Dissolution ◽  
Content Uniformity ◽  
Onset Of Action ◽  
Disintegration Time ◽  
Peg 4000 ◽  
Oral Films

The main objective of this study was to develop fast dissolving oral films of ropinirole HCl to attain quick onset of action for the better management of Parkinson’s disease. Twenty-seven formulations (F1-F27) of ropinirole oral dissolving films by solvent-casting method using 33 response surface method by using HPMC E15, Maltodextrin PEG 4000 by using Design of experiment software. Formulations were evaluated for their physical characteristics, thickness, folding endurance, tensile strength, disintegration time, drug content uniformity and drug release characteristics and found to be within the limits. Among the prepared formulations F4 showed minimum disintegration time 11 sec, maximum drug was released i.e. 99.68 ± 1.52% of drug within 10 min when compared to the other formulations and finalized as optimized formulation. FTIR data revealed that no interactions takes place between the drug and polymers used in the optimized formulation. The in vitro dissolution profiles of marketed product and optimized formulation was compared and found to be the drug released was 92.77 ± 1.52 after 50 min. Therefore, it can be a good alternative to conventional ropinirole for immediate action. In vitro evaluation of the ropinirole fast dissolving films confirmed their potential as an innovative dosage form to improve delivery and quick onset of action of ropinirole. The oral dissolving film is considered to be potentially useful for the treatment of Parkinson’s disease where quick onset of action is desired

scholarly journals 22(R)-hydroxycholesterol for dopaminergic neuronal specification of MSCs and amelioration of Parkinsonian symptoms in rats

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Manisha Singh ◽  
Manish Jain ◽  
Samrat Bose ◽  
Ashutosh Halder ◽  
Tapas Chandra Nag ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Stem Cells ◽  
Parkinson's Disease ◽  
Dental Pulp ◽  
Neuronal Cells ◽  
Human Mesenchymal Stem Cells ◽  
Wistar Rat ◽  
Human Mscs ◽  
In Vitro Differentiation

AbstractOxysterols play vital roles in the human body, ranging from cell cycle regulation and progression to dopaminergic neurogenesis. While naïve human mesenchymal stem cells (hMSCs) have been explored to have neurogenic effect, there is still a grey area to explore their regenerative potential after in vitro differentiation. Hence, in the current study, we have investigated the neurogenic effect of 22(R)-hydroxycholesterol (22-HC) on hMSCs obtained from bone marrow, adipose tissue and dental pulp. Morphological and morphometric analysis revealed physical differentiation of stem cells into neuronal cells. Detailed characterization of differentiated cells affirmed generation of neuronal cells in culture. The percentage of generation of non-DA cells in the culture confirmed selective neurogenic potential of 22-HC. We substantiated the efficacy of these cells in neuro-regeneration by transplanting them into Parkinson’s disease Wistar rat model. MSCs from dental pulp had maximal regenerative effect (with 80.20 ± 1.5% in vitro differentiation efficiency) upon transplantation, as shown by various behavioural examinations and immunohistochemical tests. Subsequential analysis revealed that 22-HC yields a higher percentage of functional DA neurons and has differential effect on various tissue-specific primary human MSCs. 22-HC may be used for treating Parkinson’s disease in future with stem cells.

scholarly journals Multiple Pathways of LRRK2-G2019S/Rab10 Interaction in Dopaminergic Neurons

2021 ◽  
pp. 1-16
Author(s):  
Alison Fellgett ◽  
C. Adam Middleton ◽  
Jack Munns ◽  
Chris Ugbode ◽  
David Jaciuch ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Genetic Interaction ◽  
In Vitro Assays ◽  
Rab Proteins ◽  
Circadian Activity ◽  
Loss Of Function ◽  
Lrrk2 G2019s

Background: Inherited mutations in the LRRK2 protein are the common causes of Parkinson’s disease, but the mechanisms by which increased kinase activity of mutant LRRK2 leads to pathological events remain to be determined. In vitro assays (heterologous cell culture, phospho-protein mass spectrometry) suggest that several Rab proteins might be directly phosphorylated by LRRK2-G2019S. An in vivo screen of Rab expression in dopaminergic neurons in young adult Drosophila demonstrated a strong genetic interaction between LRRK2-G2019S and Rab10. Objective: To determine if Rab10 is necessary for LRRK2-induced pathophysiological responses in the neurons that control movement, vision, circadian activity, and memory. These four systems were chosen because they are modulated by dopaminergic neurons in both humans and flies. Methods: LRRK2-G2019S was expressed in Drosophila dopaminergic neurons and the effects of Rab10 depletion on Proboscis Extension, retinal neurophysiology, circadian activity pattern (‘sleep’), and courtship memory determined in aged flies. Results: Rab10 loss-of-function rescued LRRK2-G2019S induced bradykinesia and retinal signaling deficits. Rab10 knock-down, however, did not rescue the marked sleep phenotype which results from dopaminergic LRRK2-G2019S. Courtship memory is not affected by LRRK2, but is markedly improved by Rab10 depletion. Anatomically, both LRRK2-G2019S and Rab10 are seen in the cytoplasm and at the synaptic endings of dopaminergic neurons. Conclusion: We conclude that, in Drosophila dopaminergic neurons, Rab10 is involved in some, but not all, LRRK2-induced behavioral deficits. Therefore, variations in Rab expression may contribute to susceptibility of different dopaminergic nuclei to neurodegeneration seen in people with Parkinson’s disease.

scholarly journals Grafts Derived from an α-Synuclein Triplication Patient Mediate Functional Recovery but Develop Disease-Associated Pathology in the 6-OHDA Model of Parkinson’s Disease

2020 ◽  
pp. 1-14
Author(s):  
Shelby Shrigley ◽  
Fredrik Nilsson ◽  
Bengt Mattsson ◽  
Alessandro Fiorenzano ◽  
Janitha Mudannayake ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Lines ◽  
Functional Recovery ◽  
Embryonic Stem ◽  
Hesc Line ◽  
Alternative Source ◽  
And Function

Background: Human induced pluripotent stem cells (hiPSCs) have been proposed as an alternative source for cell replacement therapy for Parkinson’s disease (PD) and they provide the option of using the patient’s own cells. A few studies have investigated transplantation of patient-derived dopaminergic (DA) neurons in preclinical models; however, little is known about the long-term integrity and function of grafts derived from patients with PD. Objective: To assess the viability and function of DA neuron grafts derived from a patient hiPSC line with an α-synuclein gene triplication (AST18), using a clinical grade human embryonic stem cell (hESC) line (RC17) as a reference control. Methods: Cells were differentiated into ventral mesencephalic (VM)-patterned DA progenitors using an established GMP protocol. The progenitors were then either terminally differentiated to mature DA neurons in vitro or transplanted into 6-hydroxydopamine (6-OHDA) lesioned rats and their survival, maturation, function, and propensity to develop α-synuclein related pathology, were assessed in vivo. Results: Both cell lines generated functional neurons with DA properties in vitro. AST18-derived VM progenitor cells survived transplantation and matured into neuron-rich grafts similar to the RC17 cells. After 24 weeks, both cell lines produced DA-rich grafts that mediated full functional recovery; however, pathological changes were only observed in grafts derived from the α-synuclein triplication patient line. Conclusion: This data shows proof-of-principle for survival and functional recovery with familial PD patient-derived cells in the 6-OHDA model of PD. However, signs of slowly developing pathology warrants further investigation before use of autologous grafts in patients.

scholarly journals Holistic Metabolomic Laboratory-Developed Test (LDT): Development and Use for the Diagnosis of Early-Stage Parkinson’s Disease

Metabolites ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Petr G. Lokhov ◽  
Dmitry L. Maslov ◽  
Steven Lichtenberg ◽  
Oxana P. Trifonova ◽  
Elena E. Balashova
Keyword(s):  
Parkinson’S Disease ◽  
Molecular Weight ◽  
Parkinson's Disease ◽  
High Resolution Mass Spectrometry ◽  
Early Stage ◽  
Disease Diagnosis ◽  
The Body ◽  
Low Molecular Weight ◽  
Low Molecular Weight Compounds

A laboratory-developed test (LDT) is a type of in vitro diagnostic test that is developed and used within a single laboratory. The holistic metabolomic LDT integrating the currently available data on human metabolic pathways, changes in the concentrations of low-molecular-weight compounds in the human blood during diseases and other conditions, and their prevalent location in the body was developed. That is, the LDT uses all of the accumulated metabolic data relevant for disease diagnosis and high-resolution mass spectrometry with data processing by in-house software. In this study, the LDT was applied to diagnose early-stage Parkinson’s disease (PD), which currently lacks available laboratory tests. The use of the LDT for blood plasma samples confirmed its ability for such diagnostics with 73% accuracy. The diagnosis was based on relevant data, such as the detection of overrepresented metabolite sets associated with PD and other neurodegenerative diseases. Additionally, the ability of the LDT to detect normal composition of low-molecular-weight compounds in blood was demonstrated, thus providing a definition of healthy at the molecular level. This LDT approach as a screening tool can be used for the further widespread testing for other diseases, since ‘omics’ tests, to which the metabolomic LDT belongs, cover a variety of them.

scholarly journals Cytokinin Plant Hormones Have Neuroprotective Activity in In Vitro Models of Parkinson’s Disease

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 361
Author(s):  
Gabriel Gonzalez ◽  
Jiří Grúz ◽  
Cosimo Walter D’Acunto ◽  
Petr Kaňovský ◽  
Miroslav Strnad
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Neuronal Cell Death ◽  
Disease Model ◽  
Neuronal Cell ◽  
Zeatin Riboside ◽  
Neuroprotective Activity ◽  
Protective Activity

Cytokinins are adenine-based phytohormones that regulate key processes in plants, such as cell division and differentiation, root and shoot growth, apical dominance, branching, and seed germination. In preliminary studies, they have also shown protective activities against human neurodegenerative diseases. To extend knowledge of the protection (protective activity) they offer, we investigated activities of natural cytokinins against salsolinol (SAL)-induced toxicity (a Parkinson’s disease model) and glutamate (Glu)-induced death of neuron-like dopaminergic SH-SY5Y cells. We found that kinetin-3-glucoside, cis-zeatin riboside, and N6-isopentenyladenosine were active in the SAL-induced PD model. In addition, trans-, cis-zeatin, and kinetin along with the iron chelator deferoxamine (DFO) and the necroptosis inhibitor necrostatin 1 (NEC-1) significantly reduced cell death rates in the Glu-induced model. Lactate dehydrogenase assays revealed that the cytokinins provided lower neuroprotective activity than DFO and NEC-1. Moreover, they reduced apoptotic caspase-3/7 activities less strongly than DFO. However, the cytokinins had very similar effects to DFO and NEC-1 on superoxide radical production. Overall, they showed protective activity in the SAL-induced model of parkinsonian neuronal cell death and Glu-induced model of oxidative damage mainly by reduction of oxidative stress.

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