scholarly journals Quantitative study of alpha-synuclein prion-like spreading in fully oriented reconstructed neural networks reveals non-synaptic dissemination of seeding aggregates

2021 ◽  
Author(s):  
Josquin Courte ◽  
Ngoc Anh Le ◽  
Luc Bousset ◽  
Ronald Melki ◽  
Catherine Villard ◽  
...  
Keyword(s):  
Neural Networks ◽  
Alpha Synuclein ◽  
Transfer Efficiency ◽  
Synaptic Connectivity ◽  
Low Efficiency ◽  
Synaptic Structures ◽  
The Impact ◽  
First Time ◽  
The Brain

The trans-neuronal spread of protein aggregates in a prion-like manner underlies the progression of neuronal lesions in the brain of patients with synucleinopathies such as Parkinson's disease. Despite being studied actively, the mechanisms of alpha-synuclein (aSyn) aggregates propagation remain poorly understood. This hinders the development of therapeutic approaches aiming at preventing the spatial progression of intracellular inclusions in neural networks. To assess the role of synaptic structures and neuron characteristics in the transfer efficiency of aggregates with seeding propensity, we developed a novel microfluidic culture system which allows for the first time to reconstruct in vitro fully oriented and synaptically connected neural networks. This is achieved by filtering axonal growth with unidirectional "axon valves" microchannels. We exposed the presynaptic compartment of reconstructed networks to well characterized human aSyn aggregates differing in size: Fibrils and Oligomers. Both aggregates were transferred to postsynaptic neurons through active axonal transport, albeit with poor efficiency. By manipulating network maturity, we compared the transfer rate of aggregates in networks with distinct levels of synaptic connectivity. Surprisingly, we found that transfer efficiency was lower in mature networks with higher synaptic connectivity. We then investigated the seeding efficiency of endogenous aSyn in the postsynaptic population. We found that exposure to Fibrils, and not Oligomers, resulted in low efficiency trans-neuronal seeding which was restricted to postsynaptic axons. Finally, we assessed the impact of neuron characteristics and aSyn expression on the propagation of aSyn aggregates. By reconstructing chimeric networks, we found that neuron characteristics, such as the brain region from which they originate or aSyn expression levels, did not significantly impact aggregates transfer, and observed no trans-neuronal seeding where the presynaptic population did not express aSyn. Overall, we demonstrate that this novel platform uniquely allows the quantitative interrogation of original aspects of the trans-neuronal propagation of seeding pathogenic entities.

scholarly journals Quantitative Study of Alpha-Synuclein Prion-Like Spreading in Fully Oriented Reconstructed Neural Networks Reveals Non-synaptic Dissemination of Seeding Aggregates

2021 ◽  
Author(s):  
Josquin COURTE ◽  
Ngoc Anh LE ◽  
Luc BOUSSET ◽  
Ronald MELKI ◽  
Catherine VILLARD ◽  
...  
Keyword(s):  
Neural Networks ◽  
Culture System ◽  
Transfer Rate ◽  
Alpha Synuclein ◽  
Transfer Efficiency ◽  
Synaptic Connectivity ◽  
In Vivo Models ◽  
Low Efficiency ◽  
The Impact

Abstract Background: The trans-neuronal spread of protein aggregation in a prion-like manner underlies the progression of neuronal lesions in the brain of patients with synucleinopathies such as Parkinson’s disease. Despite being studied actively, the mechanisms of alpha-synuclein (aSyn) aggregates propagation remain poorly understood. Indeed, in vivo models of aSyn prion-like propagation yield results whose interpretation is hindered by the complexity of brain networks, and in vitro models have for now failed to properly model trans-neuronal propagation in synaptically connected neural networks.Results: To assess the role of synaptic structures and neuron characteristics in the transfer efficiency of aggregates with seeding propensity, we developed a novel microfluidic neuronal culture system. This system is the first to guide in vitro the development of fully oriented, synaptically connected and fluidically isolated neural networks. It thus uniquely permitted us to model the trans-neuronal propagation of aggregation: we selectively exposed the presynaptic compartment of reconstructed networks to well characterized human aSyn aggregates differing in size (Fibrils and Oligomers), and quantitatively followed their dissemination to postsynaptic neurons. Both aggregates were anterogradely transferred to through active axonal transport, albeit with poor efficiency. By manipulating network maturity, we compared the transfer rate of aggregates in networks with distinct levels of synaptic connectivity. Surprisingly, we found that transfer efficiency was lower in mature networks with higher synaptic connectivity. We then investigated the seeding efficiency of endogenous aSyn in the postsynaptic population. We found that exposure to Fibrils, and not Oligomers, resulted in low efficiency trans-neuronal seeding which was restricted to postsynaptic axons. Finally, we assessed the impact of neuron characteristics and aSyn expression on the propagation of aSyn aggregates, and found that while endogenous aSyn expression level controlled the seeding of aSyn aggregation, it did not affect the transfer rate of exogenous aggregates. Conclusion: Overall, we describe here the first culture system for reconstructing in vitro fully oriented and synaptically connected neural networks, and demonstrate it is uniquely suitable to quantitatively interrogate original aspects of the trans-neuronal propagation of prion-like aggregates.

scholarly journals Miniaturization and Automation of a Human In Vitro Blood–Brain Barrier Model for the High-Throughput Screening of Compounds in the Early Stage of Drug Discovery

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 892
Author(s):  
Elisa L. J. Moya ◽  
Elodie Vandenhaute ◽  
Eleonora Rizzi ◽  
Marie-Christine Boucau ◽  
Johan Hachani ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Blood Brain Barrier ◽  
Early Stage ◽  
Molecular Transport ◽  
Brain Barrier ◽  
Blood Brain ◽  
Cns Drugs ◽  
The Impact ◽  
The Brain

Central nervous system (CNS) diseases are one of the top causes of death worldwide. As there is a difficulty of drug penetration into the brain due to the blood–brain barrier (BBB), many CNS drugs treatments fail in clinical trials. Hence, there is a need to develop effective CNS drugs following strategies for delivery to the brain by better selecting them as early as possible during the drug discovery process. The use of in vitro BBB models has proved useful to evaluate the impact of drugs/compounds toxicity, BBB permeation rates and molecular transport mechanisms within the brain cells in academic research and early-stage drug discovery. However, these studies that require biological material (animal brain or human cells) are time-consuming and involve costly amounts of materials and plastic wastes due to the format of the models. Hence, to adapt to the high yields needed in early-stage drug discoveries for compound screenings, a patented well-established human in vitro BBB model was miniaturized and automated into a 96-well format. This replicate met all the BBB model reliability criteria to get predictive results, allowing a significant reduction in biological materials, waste and a higher screening capacity for being extensively used during early-stage drug discovery studies.

scholarly journals Phenotypic Susceptibility to Bevirimat in Isolates from HIV-1-Infected Patients without Prior Exposure to Bevirimat

2010 ◽  
Vol 54 (6) ◽  
pp. 2345-2353 ◽  
Author(s):  
Nicolas A. Margot ◽  
Craig S. Gibbs ◽  
Michael D. Miller
Keyword(s):  
Recombinant Viruses ◽  
Gag Polyprotein ◽  
New Class ◽  
Major Mutation ◽  
Hiv Drugs ◽  
The Impact ◽  
First Time ◽  
Hiv 1

ABSTRACT Bevirimat (BVM) is the first of a new class of anti-HIV drugs with a novel mode of action known as maturation inhibitors. BVM inhibits the last cleavage of the Gag polyprotein by HIV-1 protease, leading to the accumulation of the p25 capsid-small peptide 1 (SP1) intermediate and resulting in noninfectious HIV-1 virions. Early clinical studies of BVM showed that over 50% of the patients treated with BVM did not respond to treatment. We investigated the impact of prior antiretroviral (ARV) treatment and/or natural genetic diversity on BVM susceptibility by conducting in vitro phenotypic analyses of viruses made from patient samples. We generated 31 recombinant viruses containing the entire gag and protease genes from 31 plasma samples from HIV-1-infected patients with (n = 21) or without (n = 10) prior ARV experience. We found that 58% of the patient isolates tested had a >10-fold reduced susceptibility to BVM, regardless of the patient's ARV experience or the level of isolate resistance to protease inhibitors. Analysis of mutants with site-directed mutations confirmed the role of the V370A SP1 polymorphism (SP1-V7A) in resistance to BVM. Furthermore, we demonstrated for the first time that a capsid polymorphism, V362I (CA protein-V230I), is also a major mutation conferring resistance to BVM. In contrast, none of the previously defined resistance-conferring mutations in Gag selected in vitro (H358Y, L363M, L363F, A364V, A366V, or A366T) were found to occur among the viruses that we analyzed. Our results should be helpful in the design of diagnostics for prediction of the potential benefit of BVM treatment in HIV-1-infected patients.

scholarly journals Artificial Neural Network in Drug Delivery and Pharmaceutical Research

2013 ◽  
Vol 7 (1) ◽  
pp. 49-62 ◽  
Author(s):  
Vijaykumar Sutariya ◽  
Anastasia Groshev ◽  
Prabodh Sadana ◽  
Deepak Bhatia ◽  
Yashwant Pathak
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Drug Delivery ◽  
Pattern Recognition ◽  
Analytical Data ◽  
Pharmaceutical Research ◽  
Artificial Neural ◽  
The Brain

Artificial neural networks (ANNs) technology models the pattern recognition capabilities of the neural networks of the brain. Similarly to a single neuron in the brain, artificial neuron unit receives inputs from many external sources, processes them, and makes decisions. Interestingly, ANN simulates the biological nervous system and draws on analogues of adaptive biological neurons. ANNs do not require rigidly structured experimental designs and can map functions using historical or incomplete data, which makes them a powerful tool for simulation of various non-linear systems.ANNs have many applications in various fields, including engineering, psychology, medicinal chemistry and pharmaceutical research. Because of their capacity for making predictions, pattern recognition, and modeling, ANNs have been very useful in many aspects of pharmaceutical research including modeling of the brain neural network, analytical data analysis, drug modeling, protein structure and function, dosage optimization and manufacturing, pharmacokinetics and pharmacodynamics modeling, and in vitro in vivo correlations. This review discusses the applications of ANNs in drug delivery and pharmacological research.

scholarly journals Reproductive fluids, used for the in vitro production of pig embryos, result in healthy offspring and avoid aberrant placental expression of PEG3 and LUM.

2020 ◽  
Author(s):  
Evelynne Paris-Oller ◽  
Sergio Navarro-Serna ◽  
Cristina Soriano-Úbeda ◽  
Jordana Sena Lopes ◽  
Carmen Matas ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Assisted Reproductive Technologies ◽  
Culture Media ◽  
Reproductive Technologies ◽  
In Vitro Production ◽  
Aberrant Expression ◽  
Low Efficiency ◽  
The Impact

Abstract Background: In vitro embryo production (IVP) and embryo transfer (ET) are two very common assisted reproductive technologies (ART) in human and cattle. However, in pig, the combination of either procedures, or even their use separately, is still considered suboptimal due to the low efficiency of IVP plus the difficulty of performing ET in the long and contorted uterus of the sow. In addition, the potential impact of these two ART on the health of the offspring is unknown. We investigated here if the use of a modified IVP system, with natural reproductive fluids (RF) as supplements to the culture media, combined with a minimally invasive surgery to perform ET, affects the output of the own IVP system as well as the reproductive performance of the mother and placental molecular traits.Results: The blastocyst rates obtained by both in vitro systems, conventional (C-IVP) and modified (RF-IVP), were similar. Pregnancy and farrowing rates were also similar. However, when compared to in vivo control (artificial insemination, AI), litter sizes of both IVP groups were lower, while placental efficiency was higher in AI than in RF-IVP. Gene expression studies revealed aberrant expression levels for PEG3 and LUM in placental tissue for C-IVP group when compared to AI, but not for RF-IVP group.Conclusions: The use of reproductive fluids as additives for the culture media in pig IVP does not improve reproductive performance of recipient mothers but could mitigate the impact of artificial procedures in the offspring.

scholarly journals Methylmercury Epigenetics

Toxics ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 56 ◽  
Author(s):  
Megan Culbreth ◽  
Michael Aschner
Keyword(s):  
Dna Methylation ◽  
Mirna Expression ◽  
Epigenetic Modifications ◽  
Nervous System Development ◽  
Gene Promoters ◽  
Toxic Response ◽  
The Impact ◽  
The Brain

Methylmercury (MeHg) has conventionally been investigated for effects on nervous system development. As such, epigenetic modifications have become an attractive mechanistic target, and research on MeHg and epigenetics has rapidly expanded in the past decade. Although, these inquiries are a recent advance in the field, much has been learned in regards to MeHg-induced epigenetic modifications, particularly in the brain. In vitro and in vivo controlled exposure studies illustrate that MeHg effects microRNA (miRNA) expression, histone modifications, and DNA methylation both globally and at individual genes. Moreover, some effects are transgenerationally inherited, as organisms not directly exposed to MeHg exhibited biological and behavioral alterations. miRNA expression generally appears to be downregulated consequent to exposure. Further, global histone acetylation also seems to be reduced, persist at distinct gene promoters, and is contemporaneous with enhanced histone methylation. Moreover, global DNA methylation appears to decrease in brain-derived tissues, but not in the liver; however, selected individual genes in the brain are hypermethylated. Human epidemiological studies have also identified hypo- or hypermethylated individual genes, which correlated with MeHg exposure in distinct populations. Intriguingly, several observed epigenetic modifications can be correlated with known mechanisms of MeHg toxicity. Despite this knowledge, however, the functional consequences of these modifications are not entirely evident. Additional research will be necessary to fully comprehend MeHg-induced epigenetic modifications and the impact on the toxic response.

scholarly journals SCIDOT-22. INTRACEREBROVENTRICULAR DELIVERY OF TUMOR-HOMING CYTOTOXIC HUMAN INDUCED NEURAL STEM CELLS FOR TREATMENT OF BRAIN METASTASES

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi276-vi276
Author(s):  
Wulin Jiang ◽  
Alison Mercer-Smith ◽  
Juli Bago ◽  
Simon Khagi ◽  
Carey Anders ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Brain Metastases ◽  
Neural Stem Cells ◽  
Tumor Homing ◽  
Migration Assays ◽  
Induced Neural Stem Cells ◽  
First Time ◽  
The Brain

Abstract INTRODUCTION Non-small cell lung cancer (NSCLC) and breast cancer are the most common cancers that metastasize to the brain. New therapies are needed to target and eradicate metastases. We have developed genetically-engineered induced neural stem cells (hiNSCs) derived from human fibroblasts that selectively home to tumors and release the cytotoxic protein TRAIL. Building on these results, we explored the efficacy of hiNSC therapy delivered via intracerebroventricular (ICV) injections for the treatment of metastatic foci in the brain for the first time. METHODS We performed in vitro efficacy and migration assays in conjunction with in vivo studies to determine the migration, persistence, and efficacy of therapeutic hiNSCs against H460 NSCLC and triple-negative breast cancer MB231-Br tumors in the brain. Following the establishment of tumors in the brains of nude mice, hiNSCs were injected directly into the tumor or the ventricle contralateral to the tumor. The migration and persistence of hiNSCs were investigated by following the bioluminescence of the hiNSCs. The therapeutic efficacy of the hiNSCs was determined by following the bioluminescence of the tumor. RESULTS/ CONCLUSION Co-culture results demonstrated that hiNSC therapy reduced the viability of H460 and MB231-Br up to 75% and 99.8% respectively compared to non-treated controls. In vitro migration assays showed significant directional migration toward both lung and breast cancer cells within 4 days. ICV-administered hiNSC serial imaging shows that cells persisted for >1 week in the brain. Fluorescent analysis of tissue sections showed that hiNSCs co-localized with lateral and contralateral tumors within 7 days. Using H460 and MB231-Br models, kinetic tracking of intracranial tumor volumes showed intratumoral or ICV-injected therapeutic hiNSCs suppressed the growth rate of brain tumors by 31-fold and 3-fold, respectively. This work demonstrates for the first time that we can effectively deliver personalized cytotoxic tumor-homing cells through the ventricles to target brain metastases.

scholarly journals DDRE-14. HEMP DERIVED EXTRACELLULAR VESICLES (EVS): A POTENTIAL ANTI-GLIOMA THERAPY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii64-ii64
Author(s):  
Hassan Azari ◽  
Nasser Nassiri Koopaei ◽  
Mohammad-Zaman Nouri ◽  
Jesse D Hall ◽  
Nancy D Denslow ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Extracellular Vesicles ◽  
Chromatography Tandem Mass Spectrometry ◽  
Anti Cancer ◽  
Liquid Chromatography Tandem Mass ◽  
Median Diameter ◽  
The Impact ◽  
The Brain ◽  
Plant Sources

Abstract INTRODUCTION Extracellular vesicles (EVs) have been harvested from many plant sources, some of which have anti-cancer effects and some could be used as therapeutic nanodelivery vectors. Hemp plant is a natural source of cannabinoids, of which delta 9-tetrahydroxicannabinol (THC) and cannabidiol (CBD) have proven anti-cancer proprieties. HYPOTHESIS We hypothesized that hemp EVs are enriched in cannabinoids and their application will reduce glioblastoma (GBM) tumor progression. APPROACH EVs were isolated from the hemp plant using ultracentrifugation. Nanotracking analysis, electron microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS) were utilized to characterize EVs. GBM cell lines were cultured in the neuropshere assay to evaluate hemp EVs anti-glioma effects. Fluorescent-labelled EVs were used to evaluate their brain tissue distribution in orthotopic patient-derived GBM xenografts. RESULTS Hemp EVs have a median diameter of 112.6nm with a typical lipid-bilayer structure. LC-MS/MS have shown that while cannabidiolic, cannabigerolic, and tetrahydroxicannabinolic acids represent 69.1 ± 2.1%, 19.1 ± 1.6%, 6.5 ± 0.54% of the total cannabinoids in hemp EVs, CBD and THC only make 4.75 ± 0.26%, and 0.5 ± 0.3%. Hemp EVs are potent anti-glioma agents with a 7-day LD-50 of 1.04µM and 2.4µM [based on EVs total cannabinoid content] for KR-158 and L0 GBM lines, respectively. Compared to the vehicle, overnight incubation of L0 cells with 1µM hemp EVs significantly reduced GBM cell migration (630.3 ± 61.43 vs 143.7 ± 8.7). Intranasal administration of hemp EVs led to a widespread distribution in tumor bearing brain including GBM tumor core. CONCLUSION Based on these results, hemp EVs with enriched cannabinoid content exert antiglioma effect in-vitro and when delivered intranasally, are widely distributed throughout the brain and within the tumor of PDX animals. Further experiments are ongoing to address the impact of nasally-delivered hemp EVs on tumor progression and compare to the application of purified acidic cannabinoids.

The impact of the Maillard reaction on the in vitro proteolytic breakdown of bovine lactoferrin in adults and infants

2014 ◽  
Vol 5 (8) ◽  
pp. 1898-1908 ◽  
Author(s):  
Alice M. Moscovici ◽  
Yousef Joubran ◽  
Valerie Briard-Bion ◽  
Alan Mackie ◽  
Didier Dupont ◽  
...  
Keyword(s):  
Maillard Reaction ◽  
Bioactive Peptide ◽  
Bovine Lactoferrin ◽  
Peptide Formation ◽  
The Impact ◽  
First Time

The impact of the Maillard reaction on proteolysis of the bioactive bovine lactoferrin is comparedin vitrobetween adults and infants for the first time, coupling proteomics to elucidate bioactive peptide formation.

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