Distinct neuronal alterations distinguish two subtypes of sporadic Creutzfeldt-Jakob disease with shared dysfunctional pathways
Katie Williams, Bradley R. Groveman, Simote T. Foliaki, Brent Race, Arielle Hay, Ryan O. Walters, Tina Thomas, Gianluigi Zanusso, James A. Carroll, Cathryn L. Haigh
Katie Williams, Bradley R. Groveman, Simote T. Foliaki, Brent Race, Arielle Hay, Ryan O. Walters, Tina Thomas, Gianluigi Zanusso, James A. Carroll, Cathryn L. Haigh
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Research Article Cell biology Infectious disease Neuroscience

Distinct neuronal alterations distinguish two subtypes of sporadic Creutzfeldt-Jakob disease with shared dysfunctional pathways

Abstract

Prion diseases are a family of transmissible, neurodegenerative conditions caused by misfolded proteins called prions. Human cerebral organoids can be infected with prions from sporadic Creutzfeldt-Jakob Disease (sCJD) brain tissue. Initial experiments indicated that the cerebral organoids may be able to differentiate biological properties of different sCJD subtypes. If so, it would be possible to investigate the pathogenic similarities and differences. Herein, we investigated multiple infections of cerebral organoids with 2 sCJD subtypes, comparing hallmark features of disease as well as neuronal function and health. Our results show that, while all infections produced seeding-capable prion protein (PrP), which increased from 90–180 days after infection, a sCJD subtype preference for protease-resistant PrP deposition was observed. Both subtypes caused substantial electrophysiological dysfunction in the infected organoids, which appeared uncoupled from PrP deposition. Neuronal dysfunction was associated with changes in neurotransmitter receptors that differed between the subtypes but produced the same outcome of a shift from inhibitory toward excitatory neurotransmission. Further changes indicated shared deficits in mitochondrial dynamics, and subtype influenced alterations in intracellular signaling pathways, cytoskeletal structure, and the extracellular matrix. We conclude that cerebral organoids demonstrate both common mitochondrial deficits and sCJD subtype–specific changes in neurotransmission and organoid architecture.

Authors

Katie Williams, Bradley R. Groveman, Simote T. Foliaki, Brent Race, Arielle Hay, Ryan O. Walters, Tina Thomas, Gianluigi Zanusso, James A. Carroll, Cathryn L. Haigh

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Figure 3

Organoids have reduced mitofusin transcripts but unaltered mitochondrial function and changed autophagy proteins.

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Organoids have reduced mitofusin transcripts but unaltered mitochondrial...
(A) qRT-PCR analysis of mitochondrial fission, fusion, and mitophagy genes at 180–200 dpi shown as fold change from the NBH control (indicated by the dotted line; NBH n = 3 mock infections with 3–4 organoids sampled for each). Each dot is an individual infection, and the shading of the dot indicates the number of organoids sampled and averaged for that infection. (B) Example morphology of mitochondria at 180 dpi labelled with TOM22 and DAPI nuclear stain in several sections imaged by confocal microscopy. Scale bar: 40 μm. (C) Mitochondrial inner membrane polarization determined by JC1 fluorescence at 96 and 170 dpi from 2 MV1 and 3 MV2 infections. Each dot is an individual organoid. (D) Complex 1 activity assay at 180 dpi from 3 MV1 and 3 MV2 infections. Each dot is an individual organoid. (E) Western blotting for TOMM20 at 180 dpi, each lane is an individual organoid. (F) Quantification of E plus one more infection per infection (see Supplemental Table 5 and uncropped Western blots), each dot is an individual organoid. (E) Western blotting for LC3 and p62 at 180 dpi, each lane is an individual organoid. (F–I) Quantification of TOMM20 (F), LC3 ratio (G), total LC3 (H), and p62 (I) plus one more infection per infection (see Supplemental Table 5 and uncropped Western blots), each dot is an individual organoid. *P < 0.05, **P < 0.01, ***P < 0.001 Student’s t test (A) or 1-way ANOVA with Tukey’s secondary test (C, D, F, and H–J).