prion disease Flashcards
(24 cards)
What are prion diseases?
Prion diseases are rare, fatal neurodegenerative disorders caused by the accumulation of misfolded prion proteins (PrPSc) that trigger protein aggregation and neuronal death.
What are transmissible spongiform encephalopathies (TSEs)?
TSEs are another name for prion diseases, reflecting the characteristic spongy appearance of infected brain tissue.
What are the hallmark features of prion diseases?
Spongiosis, astrocytosis, synapse loss, and neuronal cell death.
What is the characteristic EEG finding in prion diseases?
Periodic sharp wave complexes (PSWC), seen in later stages.
What is the infectious component in prion diseases?
PrPSc, a misfolded form of PrPC, the normal cellular prion protein.
How does PrPSc differ from PrPC?
PrPC has mainly alpha-helical structure; PrPSc has a beta-sheet-rich structure, making it resistant to degradation.
How does PrPSc propagate in the brain?
PrPSc interacts with PrPC, catalyzing its conversion into PrPSc, creating a self-propagating cycle.
What role does the Prnp gene play in prion diseases?
The Prnp gene encodes PrPC. Mutations in this gene can lead to inherited prion diseases.
What are common animal prion diseases?
Scrapie, Bovine Spongiform Encephalopathy (BSE), Chronic Wasting Disease (CWD), Transmissible Mink Encephalopathy, Feline Spongiform Encephalopathy.
What are common human prion diseases?
Kuru, Creutzfeldt-Jakob Disease (CJD), Variant Creutzfeldt-Jakob Disease (vCJD), Gerstmann-Straussler-Scheinker (GSS) Syndrome, Fatal Familial Insomnia (FFI).
What is scrapie, and how was it identified as transmissible?
Scrapie is a sheep prion disease identified as transmissible in 1936 after intraocular inoculation experiments.
What is Kuru, and how was it transmitted?
Kuru spread via ritualistic cannibalism in Papua New Guinea. Banning this practice in the 1950s led to the disease’s near-eradication.
How did Bovine Spongiform Encephalopathy (BSE) spread?
BSE spread through contaminated cattle feed and led to variant CJD (vCJD) in humans.
What are the four types of Creutzfeldt-Jakob Disease (CJD)?
Sporadic (sCJD) – Most common (85-90% of cases). Genetic (gCJD) – Linked to Prnp gene mutations (10-15% of cases). Iatrogenic (iCJD) – Spread via contaminated medical equipment. Variant (vCJD) – Acquired from BSE-contaminated beef.
What are common symptoms of CJD?
Rapidly progressing dementia, movement disorders, and PSWC on EEG.
What are the three main pathways for prion disease transmission?
Sporadic – Random misfolding of PrPC. Inherited – Genetic mutations in Prnp. Acquired – Transmission via infected tissue (e.g., vCJD, Kuru).
What is iatrogenic transmission in prion diseases?
Transmission via contaminated medical equipment or surgical tools.
Why are prions resistant to conventional decontamination methods?
Their beta-sheet structure makes them highly stable and resistant to heat, radiation, and common disinfectants.
What is the most effective method to destroy prions?
High-concentration sodium hydroxide can hydrolyze prion proteins and destroy their structure.
What is the RML (Rocky Mountain Laboratory) mouse model?
A prion disease model where mice are inoculated with prion-infected brain tissue, mimicking human disease progression.
What are common findings in RML models?
Synapse loss (seen via electron microscopy). Neuronal loss (visible as spongiosis). Astrocytosis in the hippocampus.
Are there any cures for prion diseases?
No cures currently exist; all prion diseases are fatal.
What drugs have been explored for prion treatment?
Trazodone and DBM (dibenzoazepine derivative).
What categories of treatments are being explored for prion diseases?
Chemical-based anti-prion compounds, repurposed drugs, antibiotics, natural compounds, immunotherapy.
