Transmissible spongiform encephalopathies (TSE) virus-induced amyloidoses of the central nervous system (CNS)

1991 ◽  
Vol 7 (5) ◽  
pp. 562-566 ◽  
Author(s):  
H. Diringer
2000 ◽  
Vol 81 (11) ◽  
pp. 2813-2821 ◽  
Author(s):  
Markus Glatzel ◽  
Adriano Aguzzi

Transmissible spongiform encephalopathies are often propagated by extracerebral inoculation. The mechanism of spread from peripheral portals of entry to the central nervous system (neuroinvasion) is complex: while lymphatic organs typically show early accumulation of prions, and B-cells and follicular dendritic cells are required for efficient neuroinvasion, actual entry into the central nervous system occurs probably via peripheral nerves and may utilize a PrPC-dependent mechanism. This study shows that transgenic mice overexpressing PrPC undergo rapid and efficient neuroinvasion upon intranerval and footpad inoculation of prions. These mice exhibited deposition of the pathological isoform of the prion protein (PrPSc) and infectivity in specific portions of the central and peripheral sensory pathways, but almost no splenic PrPSc accumulation. In contrast, wild-type mice always accumulated splenic PrPSc, and had widespread deposition of PrPSc throughout the central nervous system even when prions were injected directly into the sciatic nerve. These results indicate that a lympho-neural sequence of spread occurs in wild-type mice even upon intranerval inoculation, while overexpression of PrPC leads to substantial predilection of intranerval over lymphoreticular spread. The rate of transport of infectivity in peripheral nerves was ca. 0·7 mm per day, and prion infectivity titres of sciatic nerves were much higher in tga20 than in wild-type mice, suggesting that overexpression of PrPC modulates the capacity for intranerval transport.


2013 ◽  
Vol 94 (6) ◽  
pp. 1435-1440 ◽  
Author(s):  
Sophie Halliez ◽  
Nathalie Chesnais ◽  
Giovanna Mallucci ◽  
Marthe Vilotte ◽  
Christelle Langevin ◽  
...  

In naturally acquired transmissible spongiform encephalopathies, the pathogenic agents or prions spread from the sites of initial peripheral uptake or replication to the brain where they cause progressive and fatal neurodegeneration. Routing via the peripheral nervous system is considered to be one of the main pathways to the central nervous system. Replication of prions in Schwann cells is viewed as a potentially important mechanism for efficient prion spread along nerves. Here we used a Cre-loxP mouse transgenetic approach to disrupt host-encoded prion protein (PrPC) specifically in myelinating Schwann cells. Despite the use of infection routes targeting highly myelinated nerves, there was no alteration in mouse prion pathogenesis, suggesting that conversion-dependent, centripetal spread of prions does not crucially rely on PrPC expressed by myelinating Schwann cells.


Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2287
Author(s):  
Anthony E. Kincaid

Prion diseases, or transmissible spongiform encephalopathies (TSEs), are a class of fatal neurodegenerative diseases caused by the entry and spread of infectious prion proteins (PrPSc) in the central nervous system (CNS). These diseases are endemic to certain mammalian animal species that use their sense of smell for a variety of purposes and therefore expose their nasal cavity (NC) to PrPSc in the environment. Prion diseases that affect humans are either inherited due to a mutation of the gene that encodes the prion protein, acquired by exposure to contaminated tissues or medical devices, or develop without a known cause (referred to as sporadic). The purpose of this review is to identify components of the NC that are involved in prion transport and to summarize the evidence that the NC serves as a route of entry (centripetal spread) and/or a source of shedding (centrifugal spread) of PrPSc, and thus plays a role in the pathogenesis of the TSEs.


Author(s):  
Gladys Harrison

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.


Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.


Author(s):  
Ezzatollah Keyhani

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.


Author(s):  
S.S. Spicer ◽  
B.A. Schulte

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.


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