scholarly journals The uptake of tau amyloid fibrils is facilitated by the cellular prion protein and hampers prion propagation in cultured cells

2020 ◽  
Vol 155 (5) ◽  
pp. 577-591 ◽  
Author(s):  
Elena De Cecco ◽  
Luigi Celauro ◽  
Silvia Vanni ◽  
Micaela Grandolfo ◽  
Edoardo Bistaffa ◽  
...  
2020 ◽  
Author(s):  
Elena De Cecco ◽  
Luigi Celauro ◽  
Silvia Vanni ◽  
Micaela Grandolfo ◽  
Adriano Aguzzi ◽  
...  

AbstractTauopathies are prevalent, invariably fatal brain diseases for which no cure is available. Tauopathies progressively affect the brain through cell-to-cell transfer of tau protein amyloids, yet the spreading mechanisms are unknown. Here we show that the cellular prion protein (PrPC) facilitates the uptake of tau aggregates by cultured cells, possibly by acting as an endocytic receptor. In mouse neuroblastoma cells, we found that tau amyloids bind to PrPC; internalization of tau fibrils was reduced in isogenic cells devoid of the gene encoding PrPC. Antibodies against N-proximal epitopes of PrPC impaired the binding of tau amyloids and decreased their uptake. Surprisingly, exposure of chronically prion-infected cells to tau amyloids reduced the accumulation of aggregated prion protein; this effect lasted for more than 72 hours after amyloid removal. These results point to bidirectional interactions between the two proteins: whilst PrPC mediates the entrance of tau fibrils in cells, PrPSc buildup is greatly reduced in their presence, possibly because of an impairment in the prion conversion process.


2006 ◽  
Vol 81 (6) ◽  
pp. 2831-2837 ◽  
Author(s):  
Eric M. Norstrom ◽  
Mark F. Ciaccio ◽  
Benjamin Rassbach ◽  
Robert Wollmann ◽  
James A. Mastrianni

ABSTRACT Prion diseases are transmissible neurodegenerative diseases caused by a conformational isoform of the prion protein (PrP), a host-encoded cell surface sialoglycoprotein. Recent evidence suggests a cytosolic fraction of PrP (cyPrP) functions either as an initiating factor or toxic element of prion disease. When expressed in cultured cells, cyPrP acquires properties of the infectious conformation of PrP (PrPSc), including insolubility, protease resistance, aggregation, and toxicity. Transgenic mice (2D1 and 1D4 lines) that coexpress cyPrP and PrPC exhibit focal cerebellar atrophy, scratching behavior, and gait abnormalities suggestive of prion disease, although they lack protease-resistant PrP. To determine if the coexpression of PrPC is necessary or inhibitory to the phenotype of these mice, we crossed Tg1D4(Prnp +/+ ) mice with PrP-ablated mice (TgPrnp o/o) to generate Tg1D4(Prnp o/o) mice and followed the development of disease and pathological phenotype. We found no difference in the onset of symptoms or the clinical or pathological phenotype of disease between Tg1D4(Prnp +/+ ) and Tg1D4(Prnp o/o) mice, suggesting that cyPrP and PrPC function independently in the disease state. Additionally, Tg1D4(Prnp o/o) mice were resistant to challenge with mouse-adapted scrapie (RML), suggesting cyPrP is inaccessible to PrPSc. We conclude that disease phenotype and cellular toxicity associated with the expression of cyPrP are independent of PrPC and the generation of typical prion disease.


1997 ◽  
Vol 94 (19) ◽  
pp. 10069-10074 ◽  
Author(s):  
K. Kaneko ◽  
L. Zulianello ◽  
M. Scott ◽  
C. M. Cooper ◽  
A. C. Wallace ◽  
...  

2008 ◽  
Vol 63 (6) ◽  
pp. 747-755 ◽  
Author(s):  
Driss El Moustaine ◽  
Joan Torrent ◽  
Reinhard Lange

Copper ions (Cu2+) and heparan sulfate (HS) are suspected to act as regulatory agents in the conversion of cellular prion protein (PrPC) to its infectious isoform. However, the mechanism of this reaction is still largely unknown. Our previous report suggested multidimensional pathways for structural alterations of PrP, which may be modulated by high pressure (HP). Here we use HP to investigate the effects of Cu2+ and HS binding on PrP conformational changes and assembly. In the presence of Cu2+, amyloid fibrils are formed only under HP. In contrast, in the presence of HS, fibrils are formed at atmospheric pressure, but not under HP. Both compounds appear to compete for the same binding site, since HS-supported fibril formation is quenched by Cu2+. Inversely, Cu2+- mediated fibril formation under HP is inhibited by HS.


2017 ◽  
Vol 55 (3) ◽  
pp. 2384-2396 ◽  
Author(s):  
Sang-Gyun Kang ◽  
Chiye Kim ◽  
Judd Aiken ◽  
Han Sang Yoo ◽  
Debbie McKenzie

Glycobiology ◽  
1993 ◽  
Vol 3 (4) ◽  
pp. 319-329 ◽  
Author(s):  
David R. Borchelt ◽  
Mark Rogers ◽  
Neil Stahl ◽  
Glenn Telling ◽  
Stanley B. Prusiner

2006 ◽  
Vol 281 (19) ◽  
pp. 13828-13836 ◽  
Author(s):  
Vera Novitskaya ◽  
Olga V. Bocharova ◽  
Igor Bronstein ◽  
Ilia V. Baskakov

2004 ◽  
Vol 85 (11) ◽  
pp. 3473-3482 ◽  
Author(s):  
Chan-Lan Kim ◽  
Ayako Karino ◽  
Naotaka Ishiguro ◽  
Morikazu Shinagawa ◽  
Motoyoshi Sato ◽  
...  

The C-terminal portion of the prion protein (PrP), corresponding to a protease-resistant core fragment of the abnormal isoform of the prion protein (PrPSc), is essential for prion propagation. Antibodies to the C-terminal portion of PrP are known to inhibit PrPSc accumulation in cells persistently infected with prions. Here it was shown that, in addition to monoclonal antibodies (mAbs) to the C-terminal portion of PrP, a mAb recognizing the octapeptide repeat region in the N-terminal part of PrP that is dispensable for PrPSc formation reduced PrPSc accumulation in cells persistently infected with prions. The 50 % effective dose was as low as ∼1 nM, and, regardless of their epitope specificity, the inhibitory mAbs shared the ability to bind cellular prion protein (PrPC) expressed on the cell surface. Flow cytometric analysis revealed that mAbs that bound to the cell surface during cell culture were not internalized even after their withdrawal from the growth medium. Retention of the mAb–PrPC complex on the cell surface was also confirmed by the fact that internalization was enhanced by treatment of cells with dextran sulfate. These results suggested that anti-PrP mAb antagonizes PrPSc formation by interfering with the regular PrPC degradation pathway.


1999 ◽  
Vol 342 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Mario SALMONA ◽  
Paolo MALESANI ◽  
Luca DE GIOIA ◽  
Stefano GORLA ◽  
Maurizio BRUSCHI ◽  
...  

Prion diseases are marked by the cerebral accumulation of conformationally modified forms of the cellular prion protein (PrPC), known as PrPres. The region comprising the residues 106-126 of human PrP seems to have a key role in this conformational conversion, because a synthetic peptide homologous with this sequence (PrP106-126) adopts different secondary structures in different environments. To investigate the molecular determinants of the physicochemical characteristics of PrP106-126, we synthesized a series of analogues including PrP106-126 HD, PrP106-126 A and PrP106-126 K, with L-His → D-His, His → Ala and His → Lys substitutions respectively at position 111, PrP106-126 NH2 with amidation of the C-terminus, PrP106-126 V with an Ala → Val substition at position 117, and PrP106-126 VNH2 with an Ala → Val substitution at position 117 and amidation of the C-terminus. The analysis of the secondary structure and aggregation properties of PrP106-126 and its analogues showed the following. (1) His111 is central to the conformational changes of PrP peptides. (2) Amidation of the C-terminal Gly126 yields a predominantly random coil structure, abolishes the molecular polymorphism and decreases the propensity of PrP106-126 to generate amyloid fibrils. (3) PrP106-126 V, carrying an Ala → Val substitution at position 117, does not demonstrate a fibrillogenic ability superior to that of PrP106-126. However, the presence of Val at position 117 increases the aggregation properties of the amidated peptide. (4) Amyloid fibrils are not required for neurotoxicity because the effects of PrP106-126 NH2 on primary neuronal cultures were similar to those of the wild-type sequence. Conversely, astroglial proliferation is related to the presence of amyloid fibrils, suggesting that astrogliosis in prion encephalopathies without amyloid deposits is a mediated effect rather than a direct effect of disease-specific PrP isoforms.


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