Prion Peptide 106–126 Modulates the Aggregation of Cellular Prion Protein and Induces the Synthesis of Potentially Neurotoxic Transmembrane PrP

Abstract

In infectious and familial prion disorders, neurodegeneration is often seen without obvious deposits of the scrapie prion protein (PrP Sc ), the principal cause of neuronal death in prion disorders. In such cases, neurotoxicity must be mediated by alternative pathways of cell death. One such pathway is through a transmembrane form of PrP. We have investigated the relationship between intracellular accumulation of prion protein aggregates and the consequent up-regulation of transmembrane prion protein in a cell model. Here, we report that exposure of neuroblastoma cells to the prion peptide 106 -126 catalyzes the aggregation of cellular prion protein to a weakly proteinase K-resistant form and induces the synthesis of transmembrane prion protein, the proposed mediator of neurotoxicity in certain prion disorders. The N terminus of newly synthesized transmembrane prion protein is cleaved spontaneously on the cytosolic face of the endoplasmic reticulum, and the truncated C-terminal fragment accumulates on the cell surface. Our results suggest that neurotoxicity in prion disorders is mediated by a complex pathway involving transmembrane prion protein and not by deposits of aggregated and proteinase K-resistant PrP alone.

DLP1‐dependent mitochondrial fragmentation and redistribution mediate prion‐associated mitochondrial dysfunction and neuronal death

“…Therefore, PrP 106–126 is widely used as a model for studying PrP Sc neurotoxicity (Forloni et al ., 1993; Gu et al ., 2002; Jeong et al ., 2011). In parallel with PrP Sc , further investigation of the mechanism by which PrP Sc results in neuronal death could provide novel insights into therapeutic targets for prion (Zhu et al ., 2016).…”

Cell-Specific Metabolism and Pathogenesis of Transmembrane Prion Protein

“…Transfected cells were cultured on poly-D-lysinecoated glass coverslips overnight, fixed, and processed for staining or were first permeabilized with Triton X-100 and then processed further as described in a previous report (12). In a typical experiment, the following primary antibodies were used: monoclonal anti-PrP 3F4, 8H4, or 8B4 (1:20) or polyclonal antitubulin and antivimentin (1:40).…”

“…PrP C and PrP N3F4 cells were radiolabeled with 40 Ci/ml of Trans 35 S-label overnight in Dulbecco's modified Eagle's medium supplemented with 5% dialyzed serum. Labeled cells were washed with PBS, and cell lysates were subjected to immunoprecipitation with 3F4 or 8H4 and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography essentially as described previously (12). For Western blotting, transfected cells were lysed, and cold-methanol-precipitated proteins were electrophoretically transferred to Immobilon-P membranes (Millipore, Billerica, MA) for 2.5 h at 70 V and 4°C.…”

Prion peptide-mediated cellular prion protein overexpression and neuronal cell death can be blocked by aspirin treatment

“…The results of this study suggest the potential of aspirin for therapeutic intervention strategies in neurodegenerative diseases, including prion disease. The PrP (106-126) peptide served as a suitable model for PrPsc neurotoxicity; this is because it possesses many properties of the PrPsc protein (9)(10)(11)16,23). PrPsc protein and PrP (106-126) have been shown to induce neuronal cell death by increasing the production of prostaglandin E2 (PgE2) (8,24,25).…”

“…The prion protein peptide 106-126 [PrP (106-126)] contains the amino acid residues 106-126 of the cellular prion protein and resides near the N-terminus of PrPsc (9,10). It possesses many characteristics of the entire PrPsc protein (11).…”