Neurotoxicity and Prion Disease

AbstractThe non-toxic C-terminal fragment of the tetanus toxin (TTC) has been described as a neuroprotective molecule since it binds to Trk receptors and activates Trk-dependent signaling, activating neuronal survival pathways and inhibiting apoptosis. Previous in vivo studies have demonstrated the ability of this molecule to increase mice survival, inhibit apoptosis and regulate autophagy in murine models of neurodegenerative diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy. Prion diseases are fatal neurodegenerative disorders in which the main pathogenic event is the conversion of the cellular prion protein (PrPC) into an abnormal and misfolded isoform known as PrPSc. These diseases share different pathological features with other neurodegenerative diseases, such as amyotrophic lateral sclerosis, Parkinson’s disease or Alzheimer’s disease. Hitherto, there are no effective therapies to treat prion diseases. Here, we present a pilot study to test the therapeutic potential of TTC to treat prion diseases. C57BL6 wild-type mice and the transgenic mice Tg338, which overexpress PrPC, were intracerebrally inoculated with scrapie prions and then subjected to a treatment consisting of repeated intramuscular injections of TTC. Our results indicate that TTC displays neuroprotective effects in the murine models of prion disease reducing apoptosis, regulating autophagy and therefore increasing neuronal survival, although TTC did not increase survival time in these models.

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Detection of Prions in Brain Homogenates and CSF Samples Using a Second-Generation RT-QuIC Assay: A Useful Tool for Retrospective Analysis of Archived Samples

Pathogens ◽

10.3390/pathogens10060750 ◽

2021 ◽

Vol 10 (6) ◽

pp. 750

Author(s):

Tibor Moško ◽

Soňa Galušková ◽

Radoslav Matěj ◽

Magdalena Brůžová ◽

Karel Holada

Keyword(s):

Retrospective Analysis ◽

Prion Disease ◽

Second Generation ◽

Prion Diseases ◽

Neuropsychiatric Symptoms ◽

Final Diagnosis ◽

Post Mortem ◽

Long Term Storage ◽

Archived Samples

The possibilities for diagnosing prion diseases have shifted significantly over the last 10 years. The RT-QuIC assay option has been added for neuropsychiatric symptoms, supporting biomarkers and final post-mortem confirmation. Samples of brain homogenates used for final diagnosis, archived for many years, provide the possibility for retrospective studies. We used a second-generation RT-QuIC assay to detect seeding activity in different types of sporadic and genetic prion diseases in archival brain homogenates and post-mortem CSF samples that were 2 to 15 years old. Together, we tested 92 archival brain homogenates: 39 with definite prion disease, 28 with definite other neurological disease, and 25 with no signs of neurological disorders. The sensitivity and specificity of the assay were 97.4% and 100%, respectively. Differences were observed in gCJD E200K, compared to the sporadic CJD group. In 52 post-mortem CSF samples—24 with definite prion disease and 28 controls—we detected the inhibition of seeding reaction due to high protein content. Diluting the samples eliminated such inhibition and led to 95.8% sensitivity and 100% specificity of the assay. In conclusion, we proved the reliability of archived brain homogenates and post-mortem CSF samples for retrospective analysis by RT-QuIC after long-term storage, without changed reactivity.

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Deletion of Kif5c Does Not Alter Prion Disease Tempo or Spread in Mouse Brain

Viruses ◽

10.3390/v13071391 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1391

Author(s):

Brent Race ◽

Katie Williams ◽

Chase Baune ◽

James F. Striebel ◽

Clayton W. Winkler ◽

...

Keyword(s):

Prion Disease ◽

Molecular Motors ◽

Prion Diseases ◽

Mouse Strains ◽

Survival Times ◽

Knock Out ◽

Transport Vesicles ◽

The Central Nervous System ◽

Knock Out Mice ◽

Scrapie Strains

In prion diseases, the spread of infectious prions (PrPSc) is thought to occur within nerves and across synapses of the central nervous system (CNS). However, the mechanisms by which PrPSc moves within axons and across nerve synapses remain undetermined. Molecular motors, including kinesins and dyneins, transport many types of intracellular cargo. Kinesin-1C (KIF5C) has been shown to transport vesicles carrying the normal prion protein (PrPC) within axons, but whether KIF5C is involved in PrPSc axonal transport is unknown. The current study tested whether stereotactic inoculation in the striatum of KIF5C knock-out mice (Kif5c−/−) with 0.5 µL volumes of mouse-adapted scrapie strains 22 L or ME7 would result in an altered rate of prion spreading and/or disease timing. Groups of mice injected with each strain were euthanized at either pre-clinical time points or following the development of prion disease. Immunohistochemistry for PrP was performed on brain sections and PrPSc distribution and tempo of spread were compared between mouse strains. In these experiments, no differences in PrPSc spread, distribution or survival times were observed between C57BL/6 and Kif5c−/− mice.

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