Volatile Anesthetic Sevoflurane Precursor 1,1,1,3,3,3-Hexafluoro-2-Propanol (HFIP) Exerts an Anti-Prion Activity in Prion-Infected Culture Cells

AbstractPrion disease is a neurodegenerative disorder with progressive neurologic symptoms and accelerated cognitive decline. The causative protein of prion disease is the prion protein (PrP), and structural transition of PrP from the normal helix rich form (PrPC) to the abnormal β-sheet rich form (PrPSc) occurs in prion disease. While so far numerous therapeutic agents for prion diseases have been developed, none of them are still useful. A fluorinated alcohol, hexafluoro isopropanol (HFIP), is a precursor to the inhalational anesthetic sevoflurane and its metabolites. HFIP is also known as a robust α-helix inducer and is widely used as a solvent for highly aggregated peptides. Here we show that the α-helix-inducing activity of HFIP caused the conformational transformation of the fibrous structure of PrP into amorphous aggregates in vitro. HFIP added to the ScN2a cell medium, which continuously expresses PrPSc, reduced PrPSc protease resistance after 24-h incubation. It was also clarified that ScN2a cells are more susceptible to HFIP than any of the cells being compared. Based on these findings, HFIP is expected to develop as a therapeutic agent for prion disease.

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(De)stabilization of Alpha-Synuclein Fibrillary Aggregation by Charged and Uncharged Surfactants

International Journal of Molecular Sciences ◽

10.3390/ijms222212509 ◽

2021 ◽

Vol 22 (22) ◽

pp. 12509

Author(s):

Joana Angélica Loureiro ◽

Stéphanie Andrade ◽

Lies Goderis ◽

Ruben Gomez-Gutierrez ◽

Claudio Soto ◽

...

Keyword(s):

Secondary Structure ◽

Hydrophobic Interactions ◽

Neurodegenerative Disorder ◽

Sodium Dodecyl ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Cetyltrimethylammonium Chloride ◽

Α Helix ◽

Β Sheet

Parkinson’s disease (PD) is the second most common neurodegenerative disorder. An important hallmark of PD involves the pathological aggregation of proteins in structures known as Lewy bodies. The major component of these proteinaceous inclusions is alpha (α)-synuclein. In different conditions, α-synuclein can assume conformations rich in either α-helix or β-sheets. The mechanisms of α-synuclein misfolding, aggregation, and fibrillation remain unknown, but it is thought that β-sheet conformation of α-synuclein is responsible for its associated toxic mechanisms. To gain fundamental insights into the process of α-synuclein misfolding and aggregation, the secondary structure of this protein in the presence of charged and non-charged surfactant solutions was characterized. The selected surfactants were (anionic) sodium dodecyl sulphate (SDS), (cationic) cetyltrimethylammonium chloride (CTAC), and (uncharged) octyl β-D-glucopyranoside (OG). The effect of surfactants in α-synuclein misfolding was assessed by ultra-structural analyses, in vitro aggregation assays, and secondary structure analyses. The α-synuclein aggregation in the presence of negatively charged SDS suggests that SDS-monomer complexes stimulate the aggregation process. A reduction in the electrostatic repulsion between N- and C-terminal and in the hydrophobic interactions between the NAC (non-amyloid beta component) region and the C-terminal seems to be important to undergo aggregation. Fourier transform infrared spectroscopy (FTIR) measurements show that β-sheet structures comprise the assembly of the fibrils.

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Cholesterol transporter ATP-binding cassette A1 (ABCA1) is elevated in prion disease and affects PrPC and PrPSc concentrations in cultured cells

Journal of General Virology ◽

10.1099/vir.0.83358-0 ◽

2008 ◽

Vol 89 (6) ◽

pp. 1525-1532 ◽

Cited By ~ 15

Author(s):

Rajeev Kumar ◽

Denise McClain ◽

Rebecca Young ◽

George A. Carlson

Keyword(s):

Prion Disease ◽

Cultured Cells ◽

Prion Diseases ◽

Neuroblastoma Cells ◽

Direct Consequence ◽

Brain Regions ◽

Atp Binding ◽

N2a Cells ◽

Atp Binding Cassette

Prion diseases are transmissible neurodegenerative disorders of prion protein (PrP) conformation. Prion replication by conversion of benign PrPC isoforms into disease-specific PrPSc isoforms is intimately involved in prion disease pathogenesis and may be initiated in cholesterol-rich caveolae-like domains (CLD). Concentrations of the cholesterol transporter ATP-binding cassette A1 protein (ABCA1) are elevated in pre-clinical scrapie prion-infected mice and in prion-infected cells in vitro. Elevation of ABCA1 in prion-infected brain is not a direct consequence of local PrPSc accumulation, indeed levels of ABCA1 are comparable in brain regions that differ dramatically in the amount of PrPSc. Similarly, ABCA1 concentrations are identical in normal mice, transgenic mice overexpressing PrP and PrP knockout mice. In contrast, PrPC and PrPSc levels, but not Prnp mRNA, were increased by overexpression of ABCA1 in N2a neuroblastoma cells and scrapie prion-infected N2a cells (ScN2a). Conversely, RNAi-mediated knock down of Abca1 expression decreased the concentrations of PrPC in N2a cells and of PrPSc in ScN2a cells. These results suggest that ABCA1's effects on PrPC levels are post-translational and may reflect an increase in of PrPC stability, mediated either indirectly by increasing membrane cholesterol and CLD formation or by other functions of ABCA1. The increased supply of PrPC available for conversion would lead to increased PrPSc formation.

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Longitudinal Detection of Prion Shedding in Saliva and Urine by Chronic Wasting Disease-Infected Deer by Real-Time Quaking-Induced Conversion

Journal of Virology ◽

10.1128/jvi.01118-15 ◽

2015 ◽

Vol 89 (18) ◽

pp. 9338-9347 ◽

Cited By ~ 41

Author(s):

Davin M. Henderson ◽

Nathaniel D. Denkers ◽

Clare E. Hoover ◽

Nina Garbino ◽

Candace K. Mathiason ◽

...

Keyword(s):

Prion Disease ◽

Chronic Wasting Disease ◽

Prion Diseases ◽

Lethal Dose ◽

Disease Course ◽

Wasting Disease ◽

Daily Production ◽

Canadian Provinces ◽

Free Ranging

ABSTRACTChronic wasting disease (CWD) is an emergent, rapidly spreading prion disease of cervids. Shedding of infectious prions in saliva and urine is thought to be an important factor in CWD transmission. To help to elucidate this issue, we applied anin vitroamplification assay to determine the onset, duration, and magnitude of prion shedding in longitudinally collected saliva and urine samples from CWD-exposed white-tailed deer. We detected prion shedding as early as 3 months after CWD exposure and sustained shedding throughout the disease course. We estimated that the 50% lethal dose (LD50) for cervidized transgenic mice would be contained in 1 ml of infected deer saliva or 10 ml of urine. Given the average course of infection and daily production of these body fluids, an infected deer would shed thousands of prion infectious doses over the course of CWD infection. The direct and indirect environmental impacts of this magnitude of prion shedding on cervid and noncervid species are surely significant.IMPORTANCEChronic wasting disease (CWD) is an emerging and uniformly fatal prion disease affecting free-ranging deer and elk and is now recognized in 22 U.S. states and 2 Canadian provinces. It is unique among prion diseases in that it is transmitted naturally through wild populations. A major hypothesis to explain CWD's florid spread is that prions are shed in excreta and transmitted via direct or indirect environmental contact. Here we use a rapidin vitroassay to show that infectious doses of CWD prions are in fact shed throughout the multiyear disease course in deer. This finding is an important advance in assessing the risks posed by shed CWD prions to animals as well as humans.

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Oxidative and Inflammatory Events in Prion Diseases: Can They Be Therapeutic Targets?

Current Aging Science ◽

10.2174/1874609812666190111100205 ◽

2019 ◽

Vol 11 (4) ◽

pp. 216-225 ◽

Cited By ~ 3

Author(s):

Kedar N. Prasad ◽

Stephen C. Bondy

Keyword(s):

Oxidative Stress ◽

Prion Disease ◽

Prion Diseases ◽

Physical Interaction ◽

Follicular Dendritic Cells ◽

Human Prion Disease ◽

Endogenous Antioxidants ◽

Α Helix ◽

Β Sheet

Prion diseases are a group of incurable infectious terminal neurodegenerative diseases caused by the aggregated misfolded PrPsc in selected mammals including humans. The complex physical interaction between normal prion protein PrPc and infectious PrPsc causes conformational change from the α- helix structure of PrPc to the β-sheet structure of PrPsc, and this process is repeated. Increased oxidative stress is one of the factors that facilitate the conversion of PrPc to PrPsc. This overview presents evidence to show that increased oxidative stress and inflammation are involved in the progression of this disease. Evidence is given for the participation of redoxsensitive metals Cu and Fe with PrPsc inducing oxidative stress by disturbing the homeostasis of these metals. The fact that some antioxidants block the toxicity of misfolded PrPc peptide supports the role of oxidative stress in prion disease. After exogenous infection in mice, PrPsc enters the follicular dendritic cells where PrPsc replicates before neuroinvasion where they continue to replicate and cause inflammation leading to neurodegeneration. Therefore, reducing levels of oxidative stress and inflammation may decrease the rate of the progression of this disease. It may be an important order to reduce oxidative stress and inflammation at the same time. This may be achieved by increasing the levels of antioxidant enzymes by activating the Nrf2 pathway together with simultaneous administration of dietary and endogenous antioxidants. It is proposed that a mixture of micronutrients could enable these concurrent events thereby reducing the progression of human prion disease.

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Oral Ingestion of Synthetically Generated Recombinant Prion Is Sufficient to Cause Prion Disease in Wild-Type Mice

Pathogens ◽

10.3390/pathogens9080653 ◽

2020 ◽

Vol 9 (8) ◽

pp. 653

Author(s):

Chenhua Pan ◽

Junwei Yang ◽

Xiangyi Zhang ◽

Ying Chen ◽

Shunxiong Wei ◽

...

Keyword(s):

Prion Disease ◽

Prion Diseases ◽

Infectious Agent ◽

Oral Route ◽

Wild Type ◽

Oral Ingestion ◽

Oral Transmission ◽

Naturally Occurring ◽

First Time

Prion disease is a group of transmissible neurodegenerative disorders affecting humans and animals. The prion hypothesis postulates that PrPSc, the pathogenic conformer of host-encoded prion protein (PrP), is the unconventional proteinaceous infectious agent called prion. Supporting this hypothesis, highly infectious prion has been generated in vitro with recombinant PrP plus defined non-protein cofactors and the synthetically generated prion (recPrPSc) is capable of causing prion disease in wild-type mice through intracerebral (i.c.) or intraperitoneal (i.p.) inoculation. Given that many of the naturally occurring prion diseases are acquired through oral route, demonstrating the capability of recPrPSc to cause prion disease via oral transmission is important, but has never been proven. Here we showed for the first time that oral ingestion of recPrPSc is sufficient to cause prion disease in wild-type mice, which was supported by the development of fatal neurodegeneration in exposed mice, biochemical and histopathological analyses of diseased brains, and second round transmission. Our results demonstrate the oral transmissibility of recPrPSc and provide the missing evidence to support that the in vitro generated recPrPSc recapitulates all the important properties of naturally occurring prions.

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Acetylcholinesterase Inhibitory Potential and Antioxidant Activities of Five Cultivars of Rosa Damascena Mill. From Isparta, Turkey

Current Topics in Nutraceutical Research ◽

10.37290/ctnr2641-452x.18:354-359 ◽

2020 ◽

Vol 18 (4) ◽

pp. 354-359

Author(s):

Shirin Tarbiat ◽

Azize Simay Türütoğlu ◽

Merve Ekingen

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Free Radical ◽

Neurodegenerative Disorder ◽

Antioxidant Activities ◽

Radical Scavenging ◽

Acetylcholinesterase Activity ◽

Rosa Damascena ◽

Free Radical Damage

Alzheimer's disease is a neurodegenerative disorder characterized by memory loss and impairment of language. Alzheimer's disease is strongly associated with oxidative stress and impairment in the cholinergic pathway, which results in decreased levels of acetylcholine in certain areas of the brain. Hence, inhibition of acetylcholinesterase activity has been recognized as an acceptable treatment against Alzheimer's disease. Nature provides an array of bioactive compounds, which may protect against free radical damage and inhibit acetylcholinesterase activity. This study compares the in vitro antioxidant and anticholinesterase activities of hydroalcoholic extracts of five cultivars of Rosa Damascena Mill. petals (R. damascena 'Bulgarica', R. damascena 'Faik', R. damascena 'Iranica', R. damascena 'Complex-635' and R. damascena 'Complex-637') from Isparta, Turkey. The antioxidant activities of the hydroalcoholic extracts were tested for ferric ion reduction and DPPH radical scavenging activities. The anti-acetylcholinesterase activity was also evaluated. All rose cultivars showed a high potency for scavenging free radical and inhibiting acetylcholinesterase activity. There was a significant correlation between antioxidant and acetylcholinesterase inhibitory activity. Among cultivars, Complex-635 showed the highest inhibitory effect with an IC50 value of 3.92 µg/mL. Our results suggest that all these extracts may have the potential to treat Alzheimer's disease with Complex-635 showing more promise.

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Electromagnetic field in Alzheimer’s disease: a literature review of recent preclinical and clinical studies

Current Alzheimer Research ◽

10.2174/1567205017666201130085853 ◽

2020 ◽

Vol 17 ◽

Author(s):

Reem Habib Mohamad Ali Ahmad ◽

Marc Fakhoury ◽

Nada Lawand

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurodegenerative Disorder ◽

In Vivo Studies ◽

Key Factors ◽

Potential Benefits ◽

Preclinical And Clinical Studies ◽

The Brain

: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the progressive loss of neurons leading to cognitive and memory decay. The main signs of AD include the irregular extracellular accumulation of amyloidbeta (Aβ) protein in the brain and the hyper-phosphorylation of tau protein inside neurons. Changes in Aβ expression or aggregation are considered key factors in the pathophysiology of sporadic and early-onset AD and correlate with the cognitive decline seen in patients with AD. Despite decades of research, current approaches in the treatment of AD are only symptomatic in nature and are not effective in slowing or reversing the course of the disease. Encouragingly, recent evidence revealed that exposure to electromagnetic fields (EMF) can delay the development of AD and improve memory. This review paper discusses findings from in vitro and in vivo studies that investigate the link between EMF and AD at the cellular and behavioural level, and highlights the potential benefits of EMF as an innovative approach for the treatment of AD.

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Therapeutic Assay with the Non-toxic C-Terminal Fragment of Tetanus Toxin (TTC) in Transgenic Murine Models of Prion Disease

Molecular Neurobiology ◽

10.1007/s12035-021-02489-5 ◽

2021 ◽

Author(s):

Marina Betancor ◽

Laura Moreno-Martínez ◽

Óscar López-Pérez ◽

Alicia Otero ◽

Adelaida Hernaiz ◽

...

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Neurodegenerative Diseases ◽

Prion Disease ◽

Tetanus Toxin ◽

Neuronal Survival ◽

Prion Diseases ◽

Cellular Prion Protein ◽

Murine Models ◽

Terminal Fragment ◽

Lateral Sclerosis

AbstractThe non-toxic C-terminal fragment of the tetanus toxin (TTC) has been described as a neuroprotective molecule since it binds to Trk receptors and activates Trk-dependent signaling, activating neuronal survival pathways and inhibiting apoptosis. Previous in vivo studies have demonstrated the ability of this molecule to increase mice survival, inhibit apoptosis and regulate autophagy in murine models of neurodegenerative diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. Prion diseases are fatal neurodegenerative disorders in which the main pathogenic event is the conversion of the cellular prion protein (PrPC) into an abnormal and misfolded isoform known as PrPSc. These diseases share different pathological features with other neurodegenerative diseases, such as amyotrophic lateral sclerosis, Parkinson’s disease or Alzheimer’s disease. Hitherto, there are no effective therapies to treat prion diseases. Here, we present a pilot study to test the therapeutic potential of TTC to treat prion diseases. C57BL6 wild-type mice and the transgenic mice Tg338, which overexpress PrPC, were intracerebrally inoculated with scrapie prions and then subjected to a treatment consisting of repeated intramuscular injections of TTC. Our results indicate that TTC displays neuroprotective effects in the murine models of prion disease reducing apoptosis, regulating autophagy and therefore increasing neuronal survival, although TTC did not increase survival time in these models.

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Detection of Prions in Brain Homogenates and CSF Samples Using a Second-Generation RT-QuIC Assay: A Useful Tool for Retrospective Analysis of Archived Samples

Pathogens ◽

10.3390/pathogens10060750 ◽

2021 ◽

Vol 10 (6) ◽

pp. 750

Author(s):

Tibor Moško ◽

Soňa Galušková ◽

Radoslav Matěj ◽

Magdalena Brůžová ◽

Karel Holada

Keyword(s):

Retrospective Analysis ◽

Prion Disease ◽

Second Generation ◽

Prion Diseases ◽

Neuropsychiatric Symptoms ◽

Final Diagnosis ◽

Post Mortem ◽

Long Term Storage ◽

Archived Samples

The possibilities for diagnosing prion diseases have shifted significantly over the last 10 years. The RT-QuIC assay option has been added for neuropsychiatric symptoms, supporting biomarkers and final post-mortem confirmation. Samples of brain homogenates used for final diagnosis, archived for many years, provide the possibility for retrospective studies. We used a second-generation RT-QuIC assay to detect seeding activity in different types of sporadic and genetic prion diseases in archival brain homogenates and post-mortem CSF samples that were 2 to 15 years old. Together, we tested 92 archival brain homogenates: 39 with definite prion disease, 28 with definite other neurological disease, and 25 with no signs of neurological disorders. The sensitivity and specificity of the assay were 97.4% and 100%, respectively. Differences were observed in gCJD E200K, compared to the sporadic CJD group. In 52 post-mortem CSF samples—24 with definite prion disease and 28 controls—we detected the inhibition of seeding reaction due to high protein content. Diluting the samples eliminated such inhibition and led to 95.8% sensitivity and 100% specificity of the assay. In conclusion, we proved the reliability of archived brain homogenates and post-mortem CSF samples for retrospective analysis by RT-QuIC after long-term storage, without changed reactivity.

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Molecular Aspects of Volatile Anesthetic-Induced Organ Protection and Its Potential in Kidney Transplantation

International Journal of Molecular Sciences ◽

10.3390/ijms22052727 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2727

Author(s):

Gertrude J. Nieuwenhuijs-Moeke ◽

Dirk J. Bosch ◽

Henri G.D. Leuvenink

Keyword(s):

Kidney Transplantation ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Animal Experiments ◽

Volatile Anesthetic ◽

Organ Protection ◽

Graft Outcome ◽

Molecular Aspects

Ischemia reperfusion injury (IRI) is inevitable in kidney transplantation and negatively impacts graft and patient outcome. Reperfusion takes place in the recipient and most of the injury following ischemia and reperfusion occurs during this reperfusion phase; therefore, the intra-operative period seems an attractive window of opportunity to modulate IRI and improve short- and potentially long-term graft outcome. Commonly used volatile anesthetics such as sevoflurane and isoflurane have been shown to interfere with many of the pathophysiological processes involved in the injurious cascade of IRI. Therefore, volatile anesthetic (VA) agents might be the preferred anesthetics used during the transplantation procedure. This review highlights the molecular and cellular protective points of engagement of VA shown in in vitro studies and in vivo animal experiments, and the potential translation of these results to the clinical setting of kidney transplantation.

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