scholarly journals Queuine, a bacterial-derived hypermodified nucleobase, shows protection in in vitro models of neurodegeneration

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0253216
Author(s):  
Patricia Richard ◽  
Lucie Kozlowski ◽  
Hélène Guillorit ◽  
Patrice Garnier ◽  
Nicole C. McKnight ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
Therapeutic Potential ◽  
Mrna Translation ◽  
Alpha Synuclein ◽  
In Vitro Models ◽  
Unfolded Protein ◽  
Healthy Humans ◽  
Wobble Position ◽  
The Brain

Growing evidence suggests that human gut bacteria, which comprise the microbiome, are linked to several neurodegenerative disorders. An imbalance in the bacterial population in the gut of Parkinson’s disease (PD) and Alzheimer’s disease (AD) patients has been detected in several studies. This dysbiosis very likely decreases or increases microbiome-derived molecules that are protective or detrimental, respectively, to the human body and those changes are communicated to the brain through the so-called ‘gut-brain-axis’. The microbiome-derived molecule queuine is a hypermodified nucleobase enriched in the brain and is exclusively produced by bacteria and salvaged by humans through their gut epithelium. Queuine replaces guanine at the wobble position (position 34) of tRNAs with GUN anticodons and promotes efficient cytoplasmic and mitochondrial mRNA translation. Queuine depletion leads to protein misfolding and activation of the endoplasmic reticulum stress and unfolded protein response pathways in mice and human cells. Protein aggregation and mitochondrial impairment are often associated with neural dysfunction and neurodegeneration. To elucidate whether queuine could facilitate protein folding and prevent aggregation and mitochondrial defects that lead to proteinopathy, we tested the effect of chemically synthesized queuine, STL-101, in several in vitro models of neurodegeneration. After neurons were pretreated with STL-101 we observed a significant decrease in hyperphosphorylated alpha-synuclein, a marker of alpha-synuclein aggregation in a PD model of synucleinopathy, as well as a decrease in tau hyperphosphorylation in an acute and a chronic model of AD. Additionally, an associated increase in neuronal survival was found in cells pretreated with STL-101 in both AD models as well as in a neurotoxic model of PD. Measurement of queuine in the plasma of 180 neurologically healthy individuals suggests that healthy humans maintain protective levels of queuine. Our work has identified a new role for queuine in neuroprotection uncovering a therapeutic potential for STL-101 in neurological disorders.

scholarly journals Queuine, a bacterial derived hypermodified nucleobase, shows protection in in vitro models of neurodegeneration

2021 ◽  
Author(s):  
Patricia Richard ◽  
Xavier Manière ◽  
Lucie Kozlowski ◽  
Hélène Guillorit ◽  
Patrice Garnier ◽  
...  
Keyword(s):  
Neurodegenerative Disorders ◽  
Therapeutic Potential ◽  
Mrna Translation ◽  
Alpha Synuclein ◽  
In Vitro Models ◽  
Wobble Position ◽  
Mitochondrial Defects ◽  
Alpha Synuclein Aggregation ◽  
The Brain

AbstractGrowing evidence suggests that human gut bacteria, comprising the microbiome that communicates with the brain through the so-called ‘gut-brain-axis’, are linked to neurodegenerative disorders. Imbalances in the microbiome of Parkinson’s disease (PD) and Alzheimer’s disease (AD) patients have been detected in several studies. Queuine is a hypermodified nucleobase enriched in the brain and exclusively produced by bacteria and salvaged by humans through their gut epithelium. Queuine replaces guanine at the wobble position of tRNAs with GUN anticodons and promotes efficient cytoplasmic and mitochondrial mRNA translation.To elucidate whether queuine could facilitate protein folding and prevent aggregation and mitochondrial defects, hallmarks of neurodegenerative disorders, we tested the effect of chemically synthesized queuine, STL-101, in several in vitro models of neurodegeneration. Treatment with STL-101 led to increased neuronal survival as well as a significant decrease in hyper-phosphorylated alpha-synuclein, a marker of alpha-synuclein aggregation in a PD model and a decrease in tau hyperphosphorylation in an AD model. Our work has identified a new role for queuine in neuroprotection uncovering a therapeutic potential for STL-101 in neurological disorders.

Understanding the Physiology of the Blood-Brain Barrier: In Vitro Models

Physiology ◽  
1998 ◽  
Vol 13 (6) ◽  
pp. 287-293 ◽  
Author(s):  
Gerald A. Grant ◽  
N. Joan Abbott ◽  
Damir Janigro
Keyword(s):  
Central Nervous System ◽  
Tissue Culture ◽  
Nervous System ◽  
Blood Brain Barrier ◽  
In Vitro Models ◽  
Brain Barrier ◽  
Blood Brain ◽  
Brain Tissue Culture ◽  
The Brain

Endothelial cells exposed to inductive central nervous system factors differentiate into a blood-brain barrier phenotype. The blood-brain barrier frequently obstructs the passage of chemotherapeutics into the brain. Tissue culture systems have been developed to reproduce key properties of the intact blood-brain barrier and to allow for testing of mechanisms of transendothelial drug permeation.

scholarly journals Fragile X syndrome patient-derived neurons developing in the mouse brain show FMR1 -dependent phenotypes

2021 ◽  
Author(s):  
Marine A Krzisch ◽  
Hao A Wu ◽  
Bingbing Yuan ◽  
Troy W. Whitfield ◽  
X. Shawn Liu ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Neuronal Development ◽  
Fragile X ◽  
In Vitro Models ◽  
Synaptic Activity ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
And Function ◽  
The Brain

Abnormal neuronal development in Fragile X syndrome (FXS) is poorly understood. Data on FXS patients remain scarce and FXS animal models have failed to yield successful therapies. In vitro models do not fully recapitulate the morphology and function of human neurons. Here, we co-injected neural precursor cells (NPCs) from FXS patient-derived and corrected isogenic control induced pluripotent stem cells into the brain of neonatal immune-deprived mice. The transplanted cells populated the brain and a proportion differentiated into neurons and glial cells. Single-cell RNA sequencing of transplanted cells revealed upregulated excitatory synaptic transmission and neuronal differentiation pathways in FXS neurons. Immunofluorescence analyses showed accelerated maturation of FXS neurons after an initial delay. Additionally, increased percentages of Arc- and Egr1-positive FXS neurons and wider dendritic protrusions of mature FXS striatal medium spiny neurons pointed to an increase in synaptic activity and synaptic strength as compared to control. This transplantation approach provides new insights into the alterations of neuronal development in FXS by facilitating physiological development of cells in a 3D context, and could be used to test new therapeutic compounds correcting neuronal development defects in FXS.

scholarly journals Complex Interaction between Resident Microbiota and Misfolded Proteins: Role in Neuroinflammation and Neurodegeneration

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2476
Author(s):  
Juliana González-Sanmiguel ◽  
Christina M. A. P. Schuh ◽  
Carola Muñoz-Montesino ◽  
Pamina Contreras-Kallens ◽  
Luis G. Aguayo ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
Membrane Damage ◽  
Amyloid Β ◽  
Toxin Production ◽  
Alpha Synuclein ◽  
Oral Bacteria ◽  
Special Focus ◽  
Brain Invasion ◽  
Potential Association ◽  
The Brain

Neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and Creutzfeldt–Jakob disease (CJD) are brain conditions affecting millions of people worldwide. These diseases are associated with the presence of amyloid-β (Aβ), alpha synuclein (α-Syn) and prion protein (PrP) depositions in the brain, respectively, which lead to synaptic disconnection and subsequent progressive neuronal death. Although considerable progress has been made in elucidating the pathogenesis of these diseases, the specific mechanisms of their origins remain largely unknown. A body of research suggests a potential association between host microbiota, neuroinflammation and dementia, either directly due to bacterial brain invasion because of barrier leakage and production of toxins and inflammation, or indirectly by modulating the immune response. In the present review, we focus on the emerging topics of neuroinflammation and the association between components of the human microbiota and the deposition of Aβ, α-Syn and PrP in the brain. Special focus is given to gut and oral bacteria and biofilms and to the potential mechanisms associating microbiome dysbiosis and toxin production with neurodegeneration. The roles of neuroinflammation, protein misfolding and cellular mediators in membrane damage and increased permeability are also discussed.

scholarly journals Enhanced Therapeutic Potential of the Secretome Released from Adipose-Derived Stem Cells by PGC-1α-Driven Upregulation of Mitochondrial Proliferation

2019 ◽  
Vol 20 (22) ◽  
pp. 5589
Author(s):  
Jaeim Lee ◽  
Ok-Hee Kim ◽  
Sang Chul Lee ◽  
Kee-Hwan Kim ◽  
Jin Sun Shin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Liver Injury ◽  
Therapeutic Potential ◽  
Tissue Expression ◽  
In Vitro Models ◽  
Peroxisome Proliferator ◽  
Adipose Derived Stem Cells ◽  
Peroxisome Proliferator Activated Receptor

Peroxisome proliferator activated receptor λ coactivator 1α (PGC-1α) is a potent regulator of mitochondrial biogenesis and energy metabolism. In this study, we investigated the therapeutic potential of the secretome released from the adipose-derived stem cells (ASCs) transfected with PGC-1α (PGC-secretome). We first generated PGC-1α-overexpressing ASCs by transfecting ASCs with the plasmids harboring the gene encoding PGC-1α. Secretory materials released from PGC-1α-overexpressing ASCs were collected and their therapeutic potential was determined using in vitro (thioacetamide (TAA)-treated AML12 cells) and in vivo (70% partial hepatectomized mice) models of liver injury. In the TAA-treated AML12 cells, the PGC-secretome significantly increased cell viability, promoted expression of proliferation-related markers, such as PCNA and p-STAT, and significantly reduced the levels of reactive oxygen species (ROS). In the mice, PGC-secretome injections significantly increased liver tissue expression of proliferation-related markers more than normal secretome injections did (p < 0.05). We demonstrated that the PGC-secretome does not only have higher antioxidant and anti-inflammatory properties, but also has the potential of significantly enhancing liver regeneration in both in vivo and in vitro models of liver injury. Thus, reinforcing the mitochondrial antioxidant potential by transfecting ASCs with PGC-1α could be one of the effective strategies to enhance the therapeutic potential of ASCs.

In Vitro Study of Peritoneal Fibrosis

2007 ◽  
Vol 27 (2_suppl) ◽  
pp. 72-75
Author(s):  
Kuan-Yu Hung ◽  
Kuan-Dun Wu ◽  
Tun-Jun Tsai
Keyword(s):  
Therapeutic Potential ◽  
In Vitro Study ◽  
In Vitro Models ◽  
Drop Out ◽  
Clinical Implications ◽  
Peritoneal Fibrosis ◽  
Asian Studies ◽  
Peritoneal Tissue ◽  
Matrix Accumulation

Peritoneal fibrosis (PF) is an important issue in peritoneal dialysis (PD) because it remains one of the leading causes of patient drop-out from PD. In this review, we focus on in vitro approaches to the pathogenesis and therapeutic potential of PF and on associated clinical implications. Representative Asian studies, initiated since mid-1990s, that have investigated matrix accumulation in peritoneal tissue possibly leading to PF in the PD population will be highlighted as examples to learn how to apply this research tool. As compared with data from well-designed clinical trials, observations from in vitro models may be far from becoming solid evidence; however, they do cast new light on options for investigations into therapeutic pharmaceuticals.

scholarly journals Effects of Agents Used in the Pharmacotherapy of Cerebrovascular Disease on the Oxygen Consumption of Isolated Cerebral Mitochondria

1982 ◽  
Vol 2 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Jean-Pierre Nowicki ◽  
Eric T. MacKenzie ◽  
Brigitte Spinnewyn
Keyword(s):  
Energy Supply ◽  
Therapeutic Potential ◽  
Cerebrovascular Disorders ◽  
Respiratory Control ◽  
Base Line ◽  
Respiratory Control Ratio ◽  
Respiration Of Mitochondria ◽  
Considerable Body ◽  
The Brain

A number of drugs used in the pharmacotherapy of cerebral metabolic and vascular disease have been studied for their effects on the respiration of mitochondria isolated from the rat brain. Some of these agents increased the respiratory control ratio by more than 5% from base-line values (at p < 0.05), namely, aminophylline, dihydroergotoxine, ifenprodil, nicergoline, raubasine, and vincamine. The ability of these agents to increase the efficiency of mitochondrial respiration could be correlated with two other attributes peculiar to these five drugs: their ability to contract cerebrovascular smooth muscle when studied in vitro and their ability to decrease the volume of infarcted brain tissue following experimental occlusion of the middle cerebral artery in the cat. Papaverine and its derivatives (naftidrofuryl, viquidil, YC-93) decreased respiratory control, an effect that might correlate with their capacity to effect a vasodilatation of the cerebral vessels and their inefficacy in models of acute cerebral infarction. There is a considerable body of evidence suggesting that one of the earliest and most fundamental perturbations of cerebral ischaemia is a loss of respiratory control. Ifenprodil, vincamine, and some related “anti-ischaemic” compounds are capable of increasing respiratory control in normal cerebral mitochondria, and this capacity might well help to explain their therapeutic potential in cerebrovascular disorders in which energy supply to the brain is limited.

scholarly journals Computational Insight into the Effect of Natural Compounds on the Destabilization of Preformed Amyloid-β(1-40) Fibrils

2018 ◽  
Author(s):  
Francesco Tavanti ◽  
Alfonso Pedone ◽  
Maria Cristina Menziani
Keyword(s):  
Therapeutic Strategy ◽  
Therapeutic Potential ◽  
Structure Stability ◽  
Insoluble Form ◽  
The Brain ◽  
Identification And Characterization ◽  
Insight Into

One of the principal hallmarks of Alzheimer&rsquo;s disease (AD) is related to the aggregation of amyloid-&beta; fibrils in an insoluble form in the brain, also known as amyloidosis. Therefore, a prominent therapeutic strategy against AD consists either in blocking the amyloid aggregation and/or destroying the already formed aggregates. Natural products have shown significant therapeutic potential as amyloid inhibitors from in vitro studies as well as in vivo animal tests. In this study, the interaction of five natural biophenols (curcumin, dopamine, (-)-Epigallocatechin-3-gallate, Quercetin, and Rosmarinic acid) with the amyloid-&beta;(1-40) fibrils has been studied through computational simulations. The results allowed the identification and characterization of the different binding modalities of each compounds and their consequences on fibril dynamics and aggregation. It emerges that the lateral aggregation of the fibrils is strongly influenced by the intercalation of the ligands, which modulate the double-layered structure stability.

scholarly journals Cryo-EM structure of alpha-synuclein fibrils amplified by PMCA from PD and MSA patient brains

2021 ◽  
Author(s):  
Domenic Burger ◽  
Alexis Fenyi ◽  
Luc Bousset ◽  
Henning Stahlberg ◽  
Ronald Melki
Keyword(s):  
Multiple System Atrophy ◽  
Parkinson Disease ◽  
Neurodegenerative Diseases ◽  
Protein Misfolding ◽  
Brain Homogenate ◽  
Alpha Synuclein ◽  
Water Interface ◽  
Control Brain ◽  
Air Water Interface

Synucleinopathies are neurodegenerative diseases related to the aggregation of the protein alpha-synuclein (aSyn). Among these diseases, Parkinson disease (PD) and multiple system atrophy (MSA) are most prevalent. aSyn can readily form different fibrillar polymorphs, if exposed to an air-water interface or by templating with pre-existing fibrils. We here report the structures of three fibrillar polymorphs that were obtained after seeding monomeric aSyn with PD and MSA patients brain homogenates using protein misfolding cyclic amplification (PMCA). Seeding with a control brain homogenate did not produce fibrils, and seeding with other in vitro generated fibrillar polymorphs as a control faithfully produced polymorphs of a different type. The here determined fibril structures from PD and MSA brain tissue represent new folds, which partly resemble that of previously reported in vitro generated fibrils from Y39 phosphorylated aSyn protein. The relevance of these fibrils for synucleinopathies in humans remains to be further investigated.

scholarly journals A comparison of AAV-vector production methods for gene therapy and preclinical assessment

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marcus Davidsson ◽  
Matilde Negrini ◽  
Swantje Hauser ◽  
Alexander Svanbergsson ◽  
Marcus Lockowandt ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Therapeutic Potential ◽  
High Titer ◽  
Cell Loss ◽  
Repeated Administration ◽  
Transduction Efficiency ◽  
Aav Vector ◽  
The Brain

AbstractAdeno Associated Virus (AAV)-mediated gene expression in the brain is widely applied in the preclinical setting to investigate the therapeutic potential of specific molecular targets, characterize various cellular functions, and model central nervous system (CNS) diseases. In therapeutic applications in the clinical setting, gene therapy offers several advantages over traditional pharmacological based therapies, including the ability to directly manipulate disease mechanisms, selectively target disease-afflicted regions, and achieve long-term therapeutic protein expression in the absence of repeated administration of pharmacological agents. Next to the gold-standard iodixanol-based AAV vector production, we recently published a protocol for AAV production based on chloroform-precipitation, which allows for fast in-house production of small quantities of AAV vector without the need for specialized equipment. To validate our recent protocol, we present here a direct side-by-side comparison between vectors produced with either method in a series of in vitro and in vivo assays with a focus on transgene expression, cell loss, and neuroinflammatory responses in the brain. We do not find differences in transduction efficiency nor in any other parameter in our in vivo and in vitro panel of assessment. These results suggest that our novel protocol enables most standardly equipped laboratories to produce small batches of high quality and high titer AAV vectors for their experimental needs.

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