scholarly journals Measurements of morphological and biochemical alterations in individual neuron cells associated with early neurotoxic effects in Parkinson’s disease

2016 ◽  
Author(s):  
Su-A Yang ◽  
Jonghee Yoon ◽  
Kyoohyun Kim ◽  
YongKeun Park

AbstractParkinson’s disease (PD) is a common neurodegenerative disease. However, therapeutic methods of PD are still limited due to complex pathophysiology in PD. Here, we present optical measurements of individual neurons fromin vitroPD model using optical diffraction tomography (ODT). By measuring 3-D refractive index distribution of neurons, morphological and biochemical alterations inin-vitroPD model are quantitatively investigated. We found that neurons show apoptotic features in early PD progression. The present approach will open up new opportunities for quantitative investigation of the pathophysiology of various neurodegenerative diseases.

2021 ◽  
Author(s):  
Ariel J. Lee ◽  
DongJo Yoon ◽  
SeungYun Han ◽  
Herve Hugonnet ◽  
WeiSun Park ◽  
...  

The highly complex central nervous systems of mammals are often studied using three-dimensional (3D) in vitro primary neuronal cultures. A coupled confocal microscopy and immunofluorescence labeling are widely utilized for visualizing the 3D structures of neurons. However, this requires fixation of the neurons and is not suitable for monitoring an identical sample at multiple time points. Thus, we propose a label-free monitoring method for 3D neuronal growth based on refractive index tomograms obtained by optical diffraction tomography. The 3D morphology of the neurons was clearly visualized, and the developmental processes of neurite outgrowth in 3D spaces were analyzed for individual neurons.


2007 ◽  
Vol 15 (2) ◽  
Author(s):  
T. Kozacki ◽  
M. Kujawińska ◽  
P. Kniażewski

AbstractOptical diffraction tomography (ODT) applied to measurement of optical microelements is limited by low dynamic range, i.e., only objects with small deviations of refractive-index distribution can be measured. Therefore in this paper the limitations and errors of ODT are investigated throughout extensive numerical experiments. It is shown that these errors can be reduced by introduction of additional numerical focusing in the tomographic reconstruction algorithm. Additionally, new tomographic reconstruction algorithm using back propagation in reference medium for optical microelements measurement with known design is proposed. This hybrid reconstruction algorithm allows significant extension of ODT applicability in measurement of elements having large deviations of refractive-index distribution.


2021 ◽  
Author(s):  
Ariel Lee ◽  
DongJo Yoon ◽  
SeungYun Han ◽  
Herve Hugonnet ◽  
Wei Sun Park ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5001
Author(s):  
Alain Géloën ◽  
Karyna Isaieva ◽  
Mykola Isaiev ◽  
Olga Levinson ◽  
Emmanuelle Berger ◽  
...  

The measuring of nanoparticle toxicity faces an important limitation since it is based on metrics exposure, the concentration at which cells are exposed instead the true concentration inside the cells. In vitro studies of nanomaterials would benefit from the direct measuring of the true intracellular dose of nanoparticles. The objective of the present study was to state whether the intracellular detection of nanodiamonds is possible by measuring the refractive index. Based on optical diffraction tomography of treated live cells, the results show that unlabeled nanoparticles can be detected and localized inside cells. The results were confirmed by fluorescence measurements. Optical diffraction tomography paves the way to measuring the true intracellular concentrations and the localization of nanoparticles which will improve the dose-response paradigm of pharmacology and toxicology in the field of nanomaterials.


Author(s):  
Bhikshapathi D. V. R. N. ◽  
Srinivas A

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


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Manisha Singh ◽  
Manish Jain ◽  
Samrat Bose ◽  
Ashutosh Halder ◽  
Tapas Chandra Nag ◽  
...  

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.


2021 ◽  
pp. 1-16
Author(s):  
Alison Fellgett ◽  
C. Adam Middleton ◽  
Jack Munns ◽  
Chris Ugbode ◽  
David Jaciuch ◽  
...  

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.


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