bio sci 37 lec. 19

prion disease

aka transmissible spongiform encephalopathies (TSEs); family of rare progressive neurodegenerative disorders that affect animals, including humans, that are caused by prions

what are prion diseases distinguished by?>

all of the above

prions

abnormal, pathogenic, and transmissible agents that are able to produce abnormal folding of specific normal cellular proteins called prion proteins, that are thought to multiply via nucleation and fragmenting processes akin to growth of crystals

why are prions thought to multiply through nucleation and fragmenting

highly ordered prion protein oligomers incorporated endogenous prion proteins, thus growing in size

PRNP

gene that encodes prion proteins (normal and misfolded/mutated) that is required for animals to have susceptibility to TSEs due to prions not being able to multiply without it

PRP

denotes a prion protein

PRP^c

denotes a healthy/normal prion protein

PRP^D

denotes diseased prion proteins that are abnormally folding

PRP^Sc

denotes a specific type of PRP^D involving scapies, a type of TSE

why is PRP^c necessary for neurotoxicity and disease propagation

when even one protein is misfolded, it causes a chain reaction and TSE further propagates itself

why is PRP ultimately necessary

both of the above

how is PRP suspected to play a role in sleep patterns, memory, and maintaining myelin sheath?

long-term potentiation (LTP) and sleeping patterns are altered in mice without the PRNP gene

sporadic prion diseases

make up 80-90% of cases, prion diseases in which the cause is unknown

genetic prion diseases

make up 10-15% of cases, prion diseases caused by mutations in the PRNP gene that leads to misfolded prions

acquired prion diseases

prion diseases caused by transmission of infection from human to human for non-human animal to human; rarest type of prion diseases

zoonosis

transmission of infection from a non-human animal to a human

what is the average prognosis of prion diseases

1 year left to live, always fatal

bovine spongiform encephalopathy (mad cow disease)

type of prion disease that can cross the animal-human barrier causing a variant of CJD; primarily affects cattle but can be transmitted toward human by eating meat from infected cattle

creutzfeldt-jackob disease (CJD)

type of prion disease in humans that causes dementia by targeting cortical neurons

scrapies

type of prion disease present in sheep and goats; no clinical evidence to show it can infect humans, but it has been shown to infect primates in experimental conditions

chronic wasting disease

type of prion disease that affects cervids (elk, deer, moose) that spreads through animal-to-animal contact and contact with infected material, but there is no evidence to suggest it can infect humans

kura

type of prion disease that is present in humans

fatal famillial insomnia (FFI)

type of prion disease in humans that induces insomnia through targeting thalamic neurons

symptoms of CJD

all of the above

how are characteristic brain waves detected in CJD?

EEGs

how are structural changes in the brain caused by CJD detected?

MRIs

what appearance does brain tissue take on when one has CJD

sponge-like tissue

how is the sponge-like brain tissue seen when one has CJD

post-mortem analysis

cures and effective treatment for prion diseases

for both human and animals, there is no effective treatment or cure

how could antibodies possibly stop prion diseases?

all of the above