Neurodegenerative Disorders Flashcards
What is the role of Amyloid Precursor Protein (APP) in Alzheimer’s disease?
APP is a membrane protein that, when processed by specific enzymes, can generate beta-amyloid peptides. These peptides can aggregate and form plaques, which are characteristic of Alzheimer’s disease.
What is Alzheimer’s disease?
Alzheimer’s disease is a progressive brain disorder that impairs memory and cognitive function.
What are secretases and their role in APP processing?
Secretases are enzymes that cleave the amyloid precursor protein (APP), releasing fragments that can lead to the formation of beta-amyloid
What are the three secretases involved in amyloid-beta production?
Alpha-secretase prevents the formation of amyloid-beta by cleaving the amyloid precursor protein (APP), while beta-secretase and gamma-secretase contribute to amyloid-beta production, with beta-secretase initiating the process and gamma-secretase completing it.
What role does Apolipoprotein E play in the body?
Apolipoprotein E is involved in lipid transport and metabolism and binds to the LDL receptor to mediate the distribution and clearance of lipids.
Why is the Apolipoprotein E4 variant considered a risk factor for Alzheimer’s Disease?
The E4 variant’s structural change (two arginines instead of cysteines) makes it less stable and less efficient at binding to receptors, which affects its ability to clear beta-amyloid from the brain. This can lead to the buildup of beta-amyloid plaques, a key factor in Alzheimer’s disease.
What are the key pathological effects of Apolipoprotein E4 (ApoE4) in Alzheimer’s disease?
- Misfolding of tau proteins leading to neurodegeneration
- Impairing synaptic functions
- Increasing the buildup of amyloid-beta plaques and reducing clearance
- Mitochondrial dysfunction and impaired glucose metabolism
- Neurotoxcity and neuroinflammation
- Chlorestral efflux dysfunction
What are Tauopathies?
A group of neurodegenerative disorders characterized by the abnormal accumulation of tau protein in the brain.
What are tau proteins associated with?
Tau proteins are associated with microtubules, which help maintain cell shape and are involved in cell division and transport.
What are the two main types of tau proteins based on?
The two main types of tau proteins are based on the presence or absence of exon 10: 4-repeat (4R) tau, which includes exon 10, and 3-repeat (3R) tau, which lacks exon 10.
What happens to tau in tauopathy?
In tauopathy, tau proteins misfold and aggregate into toxic species, forming insoluble fibrils. These fibrils disrupt the neuron’s transport system, leading to cell dysfunction and death.
What changes occur in the nucleus during tauopathy?
Tauopathy leads to the condensation of chromatin in the nucleus, which can interfere with the normal expression of genes essential for cell health.
What can cause primary taupathoies?
1.Genetic mutations
2. Environmental factors
3. Aging
4. Oxidative stress
5. Inflammation
6. Impaired cellular waste clearance mechanisms.
What are some types of prion diseases?
Types of prion diseases include Creutzfeldt-Jakob disease (CJD) -common, Mad Cow Disease, Scrapie, and Kuru.
What is a prion and how do prion diseases spread?
A prion is a type of protein that can trigger normal proteins in the brain to fold abnormally. Prion diseases can affect both humans and animals and are sometimes spread to humans by infected meat products.
