Mutant prion protein enhances NMDA receptor activity, activates PKC, and triggers rapid excitotoxicity in mice
Joie Lin, … , John R. Yates III, Christina J. Sigurdson
Joie Lin, … , John R. Yates III, Christina J. Sigurdson
Published April 4, 2025
Citation Information: J Clin Invest. 2025;135(10):e186432. https://doi.org/10.1172/JCI186432.
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Research Article Aging Neuroscience

Mutant prion protein enhances NMDA receptor activity, activates PKC, and triggers rapid excitotoxicity in mice

Abstract

Neuronal hyperexcitability precedes synapse loss in certain neurodegenerative diseases, yet the synaptic membrane interactions and downstream signaling events remain unclear. The disordered amino terminus of the prion protein (PrPC) has been implicated in aberrant signaling in prion and Alzheimer’s disease. To disrupt neuronal interactions and signaling linked to the amino terminus, we CRISPR-engineered a knockin mouse expressing mutant PrPC (G92N), generating an N-linked glycosylation site between 2 functional motifs. Mice developed seizures and necrosis of hippocampal pyramidal neurons, similar to prion-infected mice and consistent with excitotoxicity. Phosphoproteomics analysis revealed phosphorylated glutamate receptors and calcium-sensitive kinases, including protein kinase C (PKC). Additionally, 92N-PrPC-expressing neurons showed persistent calcium influx as well as dendritic beading, which was rescued by an N-methyl-d-aspartate receptor (NMDAR) antagonist. Finally, survival of Prnp92N mice was prolonged by blocking active NMDAR channels. We propose that dysregulated PrPC-NMDAR–induced signaling can trigger an excitatory-inhibitory imbalance, spongiform degeneration, and neurotoxicity and that calcium dysregulation is central to PrPC-linked neurodegeneration.

Authors

Joie Lin, Julia A. Callender, Joshua E. Mayfield, Daniel B. McClatchy, Daniel Ojeda-Juárez, Mahsa Pourhamzeh, Katrin Soldau, Timothy D. Kurt, Garrett A. Danque, Helen Khuu, Josephina E. Ronson, Donald P. Pizzo, Yixing Du, Maxwell A. Gruber, Alejandro M. Sevillano, Jin Wang, Christina D. Orrú, Joy Chen, Gail Funk, Patricia Aguilar-Calvo, Brent D. Aulston, Subhojit Roy, Jong M. Rho, Jack D. Bui, Alexandra C. Newton, Stuart A. Lipton, Byron Caughey, Gentry N. Patrick, Kim Doré, John R. Yates III, Christina J. Sigurdson

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Figure 7

Reversible dendritic beading and prolonged survival of Prnp92N primary neurons and mice treated with an NMDA antagonist.

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Reversible dendritic beading and prolonged survival of Prnp92N primary n...
(A) MAP2-labeled hippocampal neurons (DIV 21–28) from Prnp92N or PrnpWT littermates. Quantification indicates the mean ± SEM. n = 102 (PrnpWT), 30 (PrnpWT/92N), and 46 (Prnp92N) neurons from 3–4 mice per genotype. Scale bar: 100 μm. (B) MAP2-labeled cortical neurons (DIV 21–28) treated with vehicle (top) or the NMDAR antagonist MK-801 for 72 hours (bottom). Quantification indicates the average ± SEM. n = 145 (PrnpWT), 117 (Prnp92N), 165 (MK801-treated PrnpWT), and 138 (MK801-treated Prnp92N) neurons from 5 mice per genotype. Scale bar: 200 μm. (C) Survival curves for mice treated with memantine or vehicle (saline). n = 17 and 15 Prnp92N saline-treated and memantine-treated mice, respectively; n = 5 and 4 PrnpWT saline-treated and memantine-treated mice, respectively. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, by 1-way ANOVA with Tukey’s multiple-comparison test (A and B). A log-rank test was used to determine survival results of Prnp92N memantine-treated versus saline control in C.