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Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species

Although misfolding of normal prion protein (PrP(C)) into abnormal conformers (PrP(Sc)) is critical for prion disease pathogenesis our current understanding of the underlying molecular pathophysiology is rudimentary. Exploiting an electrophysiology paradigm, herein we report that at least modestly p...

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Autores principales: Foliaki, Simote Totauhelotu, Lewis, Victoria, Finkelstein, David Isaac, Lawson, Victoria, Coleman, Harold Arthur, Senesi, Matteo, Islam, Abu Mohammed Taufiqual, Chen, Feng, Sarros, Shannon, Roberts, Blaine, Adlard, Paul Anthony, Collins, Steven John
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6101418/
https://www.ncbi.nlm.nih.gov/pubmed/30089152
http://dx.doi.org/10.1371/journal.ppat.1007214
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author Foliaki, Simote Totauhelotu
Lewis, Victoria
Finkelstein, David Isaac
Lawson, Victoria
Coleman, Harold Arthur
Senesi, Matteo
Islam, Abu Mohammed Taufiqual
Chen, Feng
Sarros, Shannon
Roberts, Blaine
Adlard, Paul Anthony
Collins, Steven John
author_facet Foliaki, Simote Totauhelotu
Lewis, Victoria
Finkelstein, David Isaac
Lawson, Victoria
Coleman, Harold Arthur
Senesi, Matteo
Islam, Abu Mohammed Taufiqual
Chen, Feng
Sarros, Shannon
Roberts, Blaine
Adlard, Paul Anthony
Collins, Steven John
author_sort Foliaki, Simote Totauhelotu
collection PubMed
description Although misfolding of normal prion protein (PrP(C)) into abnormal conformers (PrP(Sc)) is critical for prion disease pathogenesis our current understanding of the underlying molecular pathophysiology is rudimentary. Exploiting an electrophysiology paradigm, herein we report that at least modestly proteinase K (PK)-resistant PrP(Sc) (PrP(res)) species are acutely synaptotoxic. Brief exposure to ex vivo PrP(Sc) from two mouse-adapted prion strains (M1000 and MU02) prepared as crude brain homogenates (cM1000 and cMU02) and cell lysates from chronically M1000-infected RK13 cells (MoRK13-Inf) caused significant impairment of hippocampal CA1 region long-term potentiation (LTP), with the LTP disruption approximating that reported during the evolution of murine prion disease. Proof of PrP(Sc) (especially PrP(res)) species as the synaptotoxic agent was demonstrated by: significant rescue of LTP following selective immuno-depletion of total PrP from cM1000 (dM1000); modestly PK-treated cM1000 (PK+M1000) retaining full synaptotoxicity; and restoration of the LTP impairment when employing reconstituted, PK-eluted, immuno-precipitated M1000 preparations (PK+IP-M1000). Additional detailed electrophysiological analyses exemplified by impairment of post-tetanic potentiation (PTP) suggest possible heightened pre-synaptic vulnerability to the acute synaptotoxicity. This dysfunction correlated with cumulative insufficiency of replenishment of the readily releasable pool (RRP) of vesicles during repeated high-frequency stimulation utilised for induction of LTP. Broadly comparable results with LTP and PTP impairment were obtained utilizing hippocampal slices from PrP(C) knockout (PrPo/o) mice, with cM1000 serial dilution assessments revealing similar sensitivity of PrPo/o and wild type (WT) slices. Size fractionation chromatography demonstrated that synaptotoxic PrP correlated with PK-resistant species >100kDa, consistent with multimeric PrP(Sc), with levels of these species >6 ng/ml appearing sufficient to induce synaptic dysfunction. Biochemical analyses of hippocampal slices manifesting acute synaptotoxicity demonstrated reduced levels of multiple key synaptic proteins, albeit with noteworthy differences in PrPo/o slices, while such changes were absent in hippocampi demonstrating rescued LTP through treatment with dM1000. Our findings offer important new mechanistic insights into the synaptic impairment underlying prion disease, enhancing prospects for development of targeted effective therapies.
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spelling pubmed-61014182018-08-30 Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species Foliaki, Simote Totauhelotu Lewis, Victoria Finkelstein, David Isaac Lawson, Victoria Coleman, Harold Arthur Senesi, Matteo Islam, Abu Mohammed Taufiqual Chen, Feng Sarros, Shannon Roberts, Blaine Adlard, Paul Anthony Collins, Steven John PLoS Pathog Research Article Although misfolding of normal prion protein (PrP(C)) into abnormal conformers (PrP(Sc)) is critical for prion disease pathogenesis our current understanding of the underlying molecular pathophysiology is rudimentary. Exploiting an electrophysiology paradigm, herein we report that at least modestly proteinase K (PK)-resistant PrP(Sc) (PrP(res)) species are acutely synaptotoxic. Brief exposure to ex vivo PrP(Sc) from two mouse-adapted prion strains (M1000 and MU02) prepared as crude brain homogenates (cM1000 and cMU02) and cell lysates from chronically M1000-infected RK13 cells (MoRK13-Inf) caused significant impairment of hippocampal CA1 region long-term potentiation (LTP), with the LTP disruption approximating that reported during the evolution of murine prion disease. Proof of PrP(Sc) (especially PrP(res)) species as the synaptotoxic agent was demonstrated by: significant rescue of LTP following selective immuno-depletion of total PrP from cM1000 (dM1000); modestly PK-treated cM1000 (PK+M1000) retaining full synaptotoxicity; and restoration of the LTP impairment when employing reconstituted, PK-eluted, immuno-precipitated M1000 preparations (PK+IP-M1000). Additional detailed electrophysiological analyses exemplified by impairment of post-tetanic potentiation (PTP) suggest possible heightened pre-synaptic vulnerability to the acute synaptotoxicity. This dysfunction correlated with cumulative insufficiency of replenishment of the readily releasable pool (RRP) of vesicles during repeated high-frequency stimulation utilised for induction of LTP. Broadly comparable results with LTP and PTP impairment were obtained utilizing hippocampal slices from PrP(C) knockout (PrPo/o) mice, with cM1000 serial dilution assessments revealing similar sensitivity of PrPo/o and wild type (WT) slices. Size fractionation chromatography demonstrated that synaptotoxic PrP correlated with PK-resistant species >100kDa, consistent with multimeric PrP(Sc), with levels of these species >6 ng/ml appearing sufficient to induce synaptic dysfunction. Biochemical analyses of hippocampal slices manifesting acute synaptotoxicity demonstrated reduced levels of multiple key synaptic proteins, albeit with noteworthy differences in PrPo/o slices, while such changes were absent in hippocampi demonstrating rescued LTP through treatment with dM1000. Our findings offer important new mechanistic insights into the synaptic impairment underlying prion disease, enhancing prospects for development of targeted effective therapies. Public Library of Science 2018-08-08 /pmc/articles/PMC6101418/ /pubmed/30089152 http://dx.doi.org/10.1371/journal.ppat.1007214 Text en © 2018 Foliaki et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Foliaki, Simote Totauhelotu
Lewis, Victoria
Finkelstein, David Isaac
Lawson, Victoria
Coleman, Harold Arthur
Senesi, Matteo
Islam, Abu Mohammed Taufiqual
Chen, Feng
Sarros, Shannon
Roberts, Blaine
Adlard, Paul Anthony
Collins, Steven John
Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species
title Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species
title_full Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species
title_fullStr Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species
title_full_unstemmed Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species
title_short Prion acute synaptotoxicity is largely driven by protease-resistant PrP(Sc) species
title_sort prion acute synaptotoxicity is largely driven by protease-resistant prp(sc) species
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6101418/
https://www.ncbi.nlm.nih.gov/pubmed/30089152
http://dx.doi.org/10.1371/journal.ppat.1007214
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