Label-free detection of early oligomerization of α-synuclein and its mutants A30P/E46K through solid-state nanopores

Nanoscale ◽  
2019 ◽  
Vol 11 (13) ◽  
pp. 6480-6488 ◽  
Author(s):  
Xiaoqing Li ◽  
Xin Tong ◽  
Wenlong Lu ◽  
Dapeng Yu ◽  
Jiajie Diao ◽  
...  

Time-dependent kinetics of early oligomerization of Parkinson's disease-related α-synuclein and its mutants A30P/E46K have been studied through solid-state nanopores.

2020 ◽  
Vol 16 (1) ◽  
pp. 90-93
Author(s):  
Carmen E. Iriarte ◽  
Ian G. Macreadie

Background: Parkinson's Disease results from a loss of dopaminergic neurons, and reduced levels of the neurotransmitter dopamine. Parkinson's Disease treatments involve increasing dopamine levels through administration of L-DOPA, which can cross the blood brain barrier and be converted to dopamine in the brain. The toxicity of dopamine has previously studied but there has been little study of L-DOPA toxicity. Methods: We have compared the toxicity of dopamine and L-DOPA in the yeasts, Saccharomyces cerevisiae and Candida glabrata by cell viability assays, measuring colony forming units. Results: L-DOPA and dopamine caused time-dependent cell killing in Candida glabrata while only dopamine caused such effects in Saccharomyces cerevisiae. The toxicity of L-DOPA is much lower than dopamine. Conclusion: Candida glabrata exhibits high sensitivity to L-DOPA and may have advantages for studying the cytotoxicity of L-DOPA.


2018 ◽  
Author(s):  
Tim E. Moors ◽  
Christina A. Maat ◽  
Daniel Niedieker ◽  
Daniel Mona ◽  
Dennis Petersen ◽  
...  

AbstractPost-translational modifications of alpha-synuclein (aSyn), particularly phosphorylation at Serine 129 (Ser129-p) and truncation of its C-terminus (CTT), have been implicated in Parkinson’s disease (PD) pathology. To gain more insight in the relevance of Ser129-p and CTT aSyn under physiological and pathological conditions, we investigated their subcellular distribution patterns in normal aged and PD brains using highly-selective antibodies in combination with 3D multicolor STED microscopy. We show that CTT aSyn localizes in mitochondria in PD patients and controls, whereas the organization of Ser129-p in a cytoplasmic network is strongly associated with pathology. Nigral Lewy bodies show an onion skin-like architecture, with a structured framework of Ser129-p aSyn and neurofilaments encapsulating CTT aSyn in their core, which displayed high content of proteins and lipids by label-free CARS microscopy. The subcellular phenotypes of antibody-labeled pathology identified in this study provide evidence for a crucial role of Ser129-p aSyn in Lewy body formation.


2017 ◽  
Author(s):  
Young-Cho Kim ◽  
Nandakumar S. Narayanan

AbstractConsiderable evidence has shown that prefrontal neurons expressing D1-type dopamine receptors (D1DRs) are critical for working memory, flexibility, and timing. This line of work predicts that frontal neurons expressing D1DRs mediate cognitive processing. During timing tasks, one form this cognitive processing might take is time-dependent ramping activity — monotonic changes in firing rate over time. Thus, we hypothesized the prefrontal D1DR+ neurons would strongly exhibited time-dependent ramping during interval timing. We tested this idea using an interval-timing task in which we used optogenetics to tag D1DR+ neurons in the mouse medial frontal cortex (MFC). While 23% of MFC D1DR+ neurons exhibited ramping, this was significantly less than untagged MFC D1DR+ neurons. By contrast, MFC D1DR+ neurons had strong delta-frequency (1-4 Hz) coherence with other MFC ramping neurons. This coherence was phase-locked to cue onset and was strongest early in the interval. To test the significance of these interactions, we optogenetically stimulated MFC D1DR+ neurons early vs. late in the interval. We found that 2-Hz stimulation early in the interval was particularly effective in rescuing timing-related behavioral performance deficits in dopamine-depleted animals. These findings provide insight into MFC networks and have relevance for disorders such as Parkinson’s disease and schizophrenia.Significance StatementPrefrontal D1DRs are involved in cognitive processing and cognitive dysfunction in human diseases such as Parkinson’s disease and schizophrenia. We use optogenetics to identify these neurons, as well as neurons that are putatively connected to MFC D1DR+ neurons. We study these neurons in detail during an elementary cognitive task. These data could have relevance for cognitive deficits for Parkinson’s disease, schizophrenia, and other diseases involving frontal dopamine.


2010 ◽  
Vol 222 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Manuela Rosa ◽  
Sara Marceglia ◽  
Domenico Servello ◽  
Guglielmo Foffani ◽  
Lorenzo Rossi ◽  
...  

2021 ◽  
Author(s):  
Changlin Lian ◽  
Qiongzhen Huang ◽  
Xiangyang Zhong ◽  
Zhenyan He ◽  
Boyang Liu ◽  
...  

Abstract Background Adipose-derived human mesenchymal stem cells (hADSCs) transplantation has recently emerged as a promising method in the treatment of Parkinson's disease (PD), however, the mechanism underlying has not been fully illustrated. Methods In this study, the therapeutic effects of the striatum stereotaxic injected hADSCs in 6-OHDA-induced mouse model were evaluated. Furthermore, an in vitro model of PD was constructed using tissue-organized brain slices. And the therapeutic effect was evaluated by co-culture of hADSCs and 6-OHDA-constructed brain slice. Within the analysis of hADSCs' exocrine proteins through RNA-seq, Human protein cytokine arrays and label-free quantitative proteomics, key extracellular factors were identified in hADSCs secretion environment.The degeneration of DA neurons and apoptosis were measured in PD samples in vivo and vitro models, and the beneficial effects were evaluated through quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot,Fluoro-Jade C, Tunel assay and immunofluorescence analysis. Results In this study, we discovered that hADSCs protected the dopaminergic (DA) neurons in vivo and vitro models.we identified Pentraxin3 (PTX3) as a key extracellular factor in hADSCs secretion environment. Moreover, we found that human recombinant Pentraxin3 (rhPTX3) treatment could rescue the physiological behaviour of the PD mice in-vivo, as well as prevent DA neurons from death and increase the neuronal terminals in the Ventral tegmental area (VTA) + substantia nigra pars compacta (SNc) and striatum (STR) on the PD brain slices in-vitro. Furthermore, within testing on the pro-apoptotic markers of PD mice brain following the treatment of rhPTX3, we found that rhPTX3 can prevent the apoptosis and the degeneration of DA neurons. Conclusions Overall, the current study investigated that PTX3, a hADSCs secreted protein, played a potential role in protecting the DA neurons from apoptosis and degeneration in PD progression as well as improving the motor performances in PD mice to give a possible mechanism of how hADSCs works in the cell replacement therapy in PD. Importantly, our study also provided potential translational implications for the development of PTX3-based therapeutics in PD.


2015 ◽  
Vol 21 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Melanie Leveridge ◽  
Lee Collier ◽  
Colin Edge ◽  
Phil Hardwicke ◽  
Bill Leavens ◽  
...  

LRRK2 is a large multidomain protein containing two functional enzymatic domains: a GTPase domain and a protein kinase domain. Dominant coding mutations in the LRRK2 protein are associated with Parkinson’s disease (PD). Among such pathogenic mutations, Gly2019Ser mutation in the LRRK2 kinase domain is the most frequent cause of familial PD in Caucasians and is also found in some apparently sporadic PD cases. This mutation results in 2- to 3-fold elevated LRRK2 kinase activity compared with wild type, providing a clear clinical hypothesis for the application of kinase inhibitors in the treatment of this disease. To date, reported screening assays for LRRK2 have been based on detection of labeled adenosine triphosphate and adenosine diphosphate or on antibody-based detection of phosphorylation events. While these assays do offer a high-throughput method of monitoring LRRK2 kinase activity, they are prone to interference from autofluorescent compounds and nonspecific events. Here we describe a label-free assay for LRRK2 kinase activity using the RapidFire mass spectrometry system. This assay format was found to be highly robust and enabled a screen of 100,000 lead-like small molecules. The assay successfully identified a number of known LRRK2 chemotypes that met stringent physicochemical criteria.


2021 ◽  
Vol 11 (5) ◽  
pp. 661
Author(s):  
Monika Figura ◽  
Ewa Sitkiewicz ◽  
Bianka Świderska ◽  
Łukasz Milanowski ◽  
Stanisław Szlufik ◽  
...  

Parkinson’s disease (PD) is a progressive neurodegenerative disorder. It affects many organs. Lewy bodies—a histopathological “hallmark” of PD—are detected in about 75% of PD submandibular gland samples. We hypothesize that saliva can be a source of biomarkers of PD. The aim of the study was to evaluate and compare the salivary proteome of PD patients and healthy controls (HC). Salivary samples from 39 subjects (24 PD patients, mean age 61.6 ± 8.2; 15 HC, mean age 60.9 ± 6.7) were collected. Saliva was collected using RNA-Pro-Sal kits. Label-free LC-MS/MS mass spectrometry was performed to characterize the proteome of the saliva. IPA analysis of upstream inhibitors was performed. A total of 530 proteins and peptides were identified. We observed lower concentrations of S100-A16, ARP2/3, and VPS4B in PD group when compared to HC. We conclude that the salivary proteome composition of PD patients is different than that of healthy controls. We observed a lower concentration of proteins involved in inflammatory processes, exosome formation, and adipose tissue formation. The variability of expression of proteins between the two groups needs to be considered.


2015 ◽  
Vol 54 (2-3) ◽  
pp. 401-410 ◽  
Author(s):  
Silvia Del Din ◽  
Alan Godfrey ◽  
Shirley Coleman ◽  
Brook Galna ◽  
Sue Lord ◽  
...  

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