scholarly journals In vitro amplification of PrPSc derived from the brain and blood of sheep infected with scrapie

2008 ◽  
Vol 89 (12) ◽  
pp. 3177-3184 ◽  
Author(s):  
Leigh Thorne ◽  
Linda A. Terry
Keyword(s):  
Protein Misfolding ◽  
Prion Diseases ◽  
Infected Sheep ◽  
Highly Efficient ◽  
Polyadenylic Acid ◽  
Potential Applications ◽  
The Central Nervous System ◽  
Blood Leukocyte ◽  
The Brain

Scrapie is a fatal, naturally transmissible, neurodegenerative prion disease that affects sheep and goats and is characterized by the accumulation of a misfolded protein, PrPSc, converted from host-encoded PrPc, in the central nervous system of affected animals. Highly efficient in vitro conversion of host PrPc to PrPSc has been achieved in models of scrapie and in natural prion diseases by protein misfolding cyclic amplification (PMCA). Here, we demonstrate amplification, by serial PMCA, of PrPSc from individual sources of scrapie-infected sheep. Efficiency of amplification was affected by the pairing of the source of PrPSc with the control brain substrate of different genotypes of PrP. In line with previous studies, efficiency of amplification was greatly enhanced with the addition of a synthetic polyanion, polyadenylic acid (PolyA), facilitating rapid detection of low levels of PrPSc from body fluids such as blood. To this end PrPSc was amplified, in a 3 day PMCA assay, from blood leukocyte preparations from VRQ/VRQ scrapie-affected sheep at clinical end point. While PolyA-assisted PMCA resulted in spontaneous conversion of PrPc, we were able to distinguish blood samples from unaffected and affected sheep under controlled conditions. This study demonstrates that highly efficient amplification of PrPSc can be achieved for ovine scrapie from both brain and blood from naturally infected sheep and shows potential applications for improvements in current diagnostics and pre-mortem testing.

scholarly journals Early Generation of New PrPSc on Blood Vessels after Brain Microinjection of Scrapie in Mice

mBio ◽  
2015 ◽  
Vol 6 (5) ◽  
Author(s):  
Bruce Chesebro ◽  
James Striebel ◽  
Alejandra Rangel ◽  
Katie Phillips ◽  
Andrew Hughson ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Basement Membrane ◽  
Neurodegenerative Diseases ◽  
Blood Vessels ◽  
Protein Misfolding ◽  
Interstitial Fluid ◽  
Prion Diseases ◽  
The Central Nervous System ◽  
The Brain

ABSTRACT Aggregation of misfolded host proteins in the central nervous system is believed to be important in the pathogenic process in several neurodegenerative diseases of humans, including prion diseases, Alzheimer's disease, and Parkinson's disease. In these diseases, protein misfolding and aggregation appear to expand through a process of seeded polymerization. Prion diseases occur in both humans and animals and are experimentally transmissible orally or by injection, thus providing a controllable model of other neurodegenerative protein misfolding diseases. In rodents and ruminants, prion disease has a slow course, lasting months to years. Although prion infectivity has been detected in brain tissue at 3 to 4 weeks postinfection (p.i.), the details of early prion replication in the brain are not well understood. Here we studied the localization and quantitation of PrPSc generation in vivo starting at 30 min postmicroinjection of scrapie into the brain. In C57BL mice at 3 days p.i., generation of new PrPSc was detected by immunohistochemistry and immunoblot assays, and at 7 days p.i., new generation was confirmed by real-time quaking-induced conversion assay. The main site of new PrPSc generation was near the outer basement membrane of small and medium blood vessels. The finding and localization of replication at this site so early after injection have not been reported previously. This predominantly perivascular location suggested that structural components of the blood vessel basement membrane or perivascular astrocytes might act as cofactors in the initial generation of PrPSc. The location of PrPSc replication at the basement membrane also implies a role for the brain interstitial fluid drainage in the early infection process. IMPORTANCE Neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and prion diseases, of humans are characterized by misfolding and aggregation of certain proteins, resulting in the destruction of brain tissue. In these diseases, the damage process spreads progressively within the central nervous system, but only prion diseases are known to be transmissible between individuals. Here we used microinjection of infectious prion protein (PrPSc) into the mouse brain to model early events of iatrogenic prion transmission via surgical instruments or tissue grafts. At 3 and 7 days postinjection, we detected the generation of new PrPSc, mostly on the outer walls of blood vessels near the injection site. This location and very early replication were surprising and unique. Perivascular prion replication suggested the transport of injected PrPSc via brain interstitial fluid to the basement membranes of blood vessels, where interactions with possible cofactors made by astrocytes or endothelia might facilitate the earliest cycles of prion infection.

scholarly journals Beyond Oncological Hyperthermia: Physically Drivable Magnetic Nanobubbles as Novel Multipurpose Theranostic Carriers in the Central Nervous System

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2104 ◽  
Author(s):  
Eleonora Ficiarà ◽  
Shoeb Anwar Ansari ◽  
Monica Argenziano ◽  
Luigi Cangemi ◽  
Chiara Monge ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Brain Tumors ◽  
Ad Hoc ◽  
Superparamagnetic Iron Oxide ◽  
Conventional Radiotherapy ◽  
The Central Nervous System ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Magnetic Oxygen-Loaded Nanobubbles (MOLNBs), manufactured by adding Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on the surface of polymeric nanobubbles, are investigated as theranostic carriers for delivering oxygen and chemotherapy to brain tumors. Physicochemical and cyto-toxicological properties and in vitro internalization by human brain microvascular endothelial cells as well as the motion of MOLNBs in a static magnetic field were investigated. MOLNBs are safe oxygen-loaded vectors able to overcome the brain membranes and drivable through the Central Nervous System (CNS) to deliver their cargoes to specific sites of interest. In addition, MOLNBs are monitorable either via Magnetic Resonance Imaging (MRI) or Ultrasound (US) sonography. MOLNBs can find application in targeting brain tumors since they can enhance conventional radiotherapy and deliver chemotherapy being driven by ad hoc tailored magnetic fields under MRI and/or US monitoring.

Thiamine transport in the central nervous system

1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector
Keyword(s):  
Choroid Plexus ◽  
Intraventricular Injection ◽  
Simple Diffusion ◽  
Thiamine Transport ◽  
Choroid Plexuses ◽  
The Central Nervous System ◽  
The Brain ◽  
Thiamine Phosphates

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.

scholarly journals Efficient In Vitro Amplification of Chronic Wasting Disease PrPRES

2007 ◽  
Vol 81 (17) ◽  
pp. 9605-9608 ◽  
Author(s):  
Timothy D. Kurt ◽  
Matthew R. Perrott ◽  
Carol J. Wilusz ◽  
Jeffrey Wilusz ◽  
Surachai Supattapone ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Prion Protein ◽  
Protein Misfolding ◽  
Chronic Wasting Disease ◽  
Body Fluids ◽  
The Body ◽  
Wasting Disease ◽  
Highly Efficient ◽  
Significant Step

ABSTRACT Chronic wasting disease (CWD) of cervids is associated with conversion of the normal cervid prion protein, PrPC, to a protease-resistant conformer, PrPCWD. Here we report the use of both nondenaturing amplification and protein-misfolding cyclic amplification (PMCA) to amplify PrPCWD in vitro. Normal brains from deer, transgenic mice expressing cervid PrPC [Tg(cerPrP)1536 mice], and ferrets supported amplification. PMCA using normal Tg(cerPrP)1536 brains as the PrPC substrate produced >6.5 × 109-fold amplification after six rounds. Highly efficient in vitro amplification of PrPCWD is a significant step toward detection of PrPCWD in the body fluids or excreta of CWD-susceptible species.

scholarly journals Vascular Dysfunction Induced by Mercury Exposure

2019 ◽  
Vol 20 (10) ◽  
pp. 2435 ◽  
Author(s):  
Tetsuya Takahashi ◽  
Takayoshi Shimohata
Keyword(s):  
Oxidative Stress ◽  
Vascular Dysfunction ◽  
Brain Parenchyma ◽  
Transport Systems ◽  
Mehg Exposure ◽  
In Vivo Models ◽  
The Central Nervous System ◽  
The Brain

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.

Steps toward recovery of function after hemilabyrinthectomy in frogs

1998 ◽  
Vol 119 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Norbert Dieringer ◽  
Hans Straka
Keyword(s):  
Time Course ◽  
Recovery Of Function ◽  
Behavioral Deficits ◽  
Afferent Fibers ◽  
Vestibular Nuclear Complex ◽  
The Central Nervous System ◽  
Synaptic Changes ◽  
Necessary And Sufficient ◽  
The Brain

Removal of the labyrinthine organs on one side results in a number of severe postural and dynamic reflex deficits. Over time some of these behavioral deficits normalize again. At a chronic stage the brain of frogs exhibits a number of changes in vestibular and propriospinal circuits on the operated side that were studied in vitro. The onset of changes in the vestibular nuclear complex was delayed, became evident only after head posture had recovered by more than 50%, and was independent of the presence or absence of a degeneration of vestibular nerve afferent fibers. The time course of changes measured in the isolated spinal cord paralleled the time course of normalization of head and body posture. Results obtained after selective lesions of individual labyrinthine nerve branches show that unilateral inactivation of utricular afferent inputs is a necessary and sufficient condition to provoke postural deficits and propriospinal changes similar to those after the removal of all labyrinthine organs. The presence of multiple synaptic changes at distributed anatomic sites over different periods of time suggests that different parts of the central nervous system are involved in the normalization of different manifestations of the vestibular lesion syndrome. (Otolaryngol Head Neck Surg 1998;119:27–33.)

Dexamethasone rapidly increases hypothalamic neuropeptide Y secretion in adrenalectomized ob/ob mice

1996 ◽  
Vol 271 (1) ◽  
pp. E151-E158 ◽  
Author(s):  
H. L. Chen ◽  
D. R. Romsos
Keyword(s):  
Neuropeptide Y ◽  
Arcuate Nucleus ◽  
Rapid Onset ◽  
Brown Adipose ◽  
Specific Enhancement ◽  
Brown Adipose Tissue Thermogenesis ◽  
The Central Nervous System ◽  
Rapid Transport ◽  
The Brain

A single intracerebroventricular injection of dexamethasone (DEX) rapidly (within 30 min) suppresses brown adipose tissue thermogenesis and increases plasma insulin concentrations in adrenal-ectomized (ADX) ob/ob mice but not in ADX lean mice. Intracerebroventricular neuropeptide Y (NPY) administered intracerebroventricularly causes these same metabolic changes within 30 min in both ob/ob and lean ADX mice. We therefore hypothesized that DEX exerts these rapid-onset metabolic actions in ob/ob mice via a phenotype-specific enhancement of NPY secretion within the central nervous system. In support of this hypothesis, DEX (a type II glucocorticoid receptor agonist) administered intracerebroventricularly selectively lowered NPY concentrations in the whole hypothalamus of ADX ob/ob mice by 35% and in the arcuate nucleus region by approximately 70% within 30 min but not in the brain stem or hippocampus or in any of these regions of lean mice. DEX also functioned in vitro to enhance depolarization-dependent release of NPY from hypothalamic blocks of ADX ob/ob mice but not of ADX lean mice. Thus DEX acts in the hypothalamus of ob/ob mice in a phenotype-specific manner to evoke rapid transport of NPY from cell bodies within the arcuate nucleus to terminal regions including the dorsomedial and ventromedial hypothalamic regions for release.

The neuroepidemiology of human prion disease

2020 ◽  
pp. 367-378
Author(s):  
Patrick JM Urwin ◽  
Anna M Molesworth
Keyword(s):  
Prion Protein ◽  
Prion Disease ◽  
Protein Misfolding ◽  
Prion Diseases ◽  
Prion Protein Gene ◽  
Human Prion Disease ◽  
Disease States ◽  
Jakob Disease ◽  
The Central Nervous System ◽  
Sporadic Disease

Human prion diseases comprise a number of rare and fatal neurodegenerative conditions that result from the accumulation in the central nervous system of an abnormal form of a naturally occurring protein, called the prion protein. The diseases occur in genetic, sporadic, and acquired forms: genetic disease is associated with mutations in the prion protein gene (PRNP); sporadic disease is thought to result from a spontaneous protein misfolding event; acquired disease results from transmission of infection from an animal or another human. The potential transmissibility of the prion in any of these forms, either in disease states or during the incubation period, has implications for public health. Here we focus on Creutzfeldt-Jakob Disease (CJD), including variant Creutzfeldt-Jakob Disease (vCJD), although we will also discuss other forms of human prion disease.

scholarly journals Detection of Pathognomonic Biomarker PrPSc and the Contribution of Cell Free-Amplification Techniques to the Diagnosis of Prion Diseases

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 469
Author(s):  
Hasier Eraña ◽  
Jorge M. Charco ◽  
Ezequiel González-Miranda ◽  
Sandra García-Martínez ◽  
Rafael López-Moreno ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Protein Misfolding ◽  
Prion Diseases ◽  
Immunohistochemical Analysis ◽  
Body Fluids ◽  
Detection Methods ◽  
Transmissible Spongiform Encephalopathies ◽  
Spongiform Encephalopathies ◽  
Prion Propagation

Transmissible spongiform encephalopathies or prion diseases are rapidly progressive neurodegenerative diseases, the clinical manifestation of which can resemble other promptly evolving neurological maladies. Therefore, the unequivocal ante-mortem diagnosis is highly challenging and was only possible by histopathological and immunohistochemical analysis of the brain at necropsy. Although surrogate biomarkers of neurological damage have become invaluable to complement clinical data and provide more accurate diagnostics at early stages, other neurodegenerative diseases show similar alterations hindering the differential diagnosis. To solve that, the detection of the pathognomonic biomarker of disease, PrPSc, the aberrantly folded isoform of the prion protein, could be used. However, the amounts in easily accessible tissues or body fluids at pre-clinical or early clinical stages are extremely low for the standard detection methods. The solution comes from the recent development of in vitro prion propagation techniques, such as Protein Misfolding Cyclic Amplification (PMCA) and Real Time-Quaking Induced Conversion (RT-QuIC), which have been already applied to detect minute amounts of PrPSc in different matrixes and make early diagnosis of prion diseases feasible in a near future. Herein, the most relevant tissues and body fluids in which PrPSc has been detected in animals and humans are being reviewed, especially those in which cell-free prion propagation systems have been used with diagnostic purposes.

scholarly journals Photostimulation of Extravasation of Beta-Amyloid through the Model of Blood-Brain Barrier

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1056
Author(s):  
Ekaterina Zinchenko ◽  
Maria Klimova ◽  
Aysel Mamedova ◽  
Ilana Agranovich ◽  
Inna Blokhina ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Beta Amyloid ◽  
Brain Barrier ◽  
Therapeutic Effects ◽  
Cervical Lymph Nodes ◽  
Blood Brain ◽  
The Central Nervous System ◽  
Vitro Model ◽  
The Brain

Alzheimer’s disease (AD) is an incurable pathology associated with progressive decline in memory and cognition. Phototherapy might be a new promising and alternative strategy for the effective treatment of AD, and has been actively discussed over two decades. However, the mechanisms of therapeutic photostimulation (PS) effects on subjects with AD remain poorly understood. The goal of this study was to determine the mechanisms of therapeutic PS effects in beta-amyloid (Aβ)-injected mice. The neurological severity score and the new object recognition tests demonstrate that PS 9 J/cm2 attenuates the memory and neurological deficit in mice with AD. The immunohistochemical assay revealed a decrease in the level of Aβ in the brain and an increase of Aβ in the deep cervical lymph nodes obtained from mice with AD after PS. Using the in vitro model of the blood-brain barrier (BBB), we show a PS-mediated decrease in transendothelial resistance and in the expression of tight junction proteins as well an increase in the BBB permeability to Aβ. These findings suggest that a PS-mediated BBB opening and the activation of the lymphatic clearance of Aβ from the brain might be a crucial mechanism underlying therapeutic effects of PS in mice with AD. These pioneering data open new strategies in the development of non-pharmacological methods for therapy of AD and contribute to a better understanding of the PS effects on the central nervous system.

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