Prion Diseases Flashcards
1
Q
WHat is the pathological charcteristic of prion diseases?
A
Spongiform encephalopathy
2
Q
What are the 3 groups of prion diseases?
A
- Creutzfeld-Jakob Disease
- Fatal familial insomnia
- Kuru (aquired)
3
Q
What percentage of prion diseases are inherited?
A
~ 10-15%
4
Q
What percentage of the prion diseases are sporadic?
A
~ 85%
5
Q
What does ‘spongiform’ pathology involve?
A
- Spongy vaccules form where neurons have died
- Increased activation of astrocytes which results in scarring of Nervous tissue in brain
- Deposition of prions
- Plaques (similar to AD)
6
Q
What is a prion?
A
- Only contains protein material does not contain genetic material.
- Quite resitant to heat and disinfectants
- Infectious
- Difficult for immune system to detect
7
Q
What prion proteins are normal and expressed by humans?
A
PrPc
8
Q
What is involved in the variant form of prion protein?
A
- Called PrPSc
- More rich in Beta-sheets
- Able to convert normal PrPc into infectious PrPSc
9
Q
How can PrPsc be transmitted?
A
- Through exocytosis and endocytosis can be depositted in amyloid-like fibres
- Kills neurons
- Astrocytes invade and remove dead neurons
- Leaves behind sponey like holes in brain
10
Q
What is the normal function of PRPN?
A
- GPI-anchor allows it to be embedded in membrane of neurons particullarly in synaptic membrane
- Glycosylated
- Synaptic membrane of neurons
- Still not clear exactly what it does (may cause altered circadian rhythms and sleep patterns)
11
Q
What is Bovine spongiform encephalopathy colloquially known as?
A
Mad cow disease
12
Q
What are the differences between variant and sporadic CJD?
A
- Age of onset earlier in vCJD
- Longer duration in vCJD
13
Q
What therapies may be available for prion diseases?
A
- Stabilising PrPc conformation
- Clearence of PRPsc
- Vaccination against PrPsc
