Therapeutic approaches to neurodegen diseases Flashcards
huntingtons
loss of medium spiny neurons in caudate and putamen
mechanism of huntingtons
slippage in repeated region during DNA replication–>increase in nuber of CAGs (glutamine)
problematic in huntington gene
drug for huntingtons
tetrabenzdne
altzehimers
loss of neurons in brain
cortical shrinkage, hippocamp shrinkage, enlargement of ventricles
altz is associated with
protein aggregation and accumulation
hallmarts of altz
neurofibrillary tangles–agg/accumulation of Tau protein fibrils
accumulation of amyloid containing plaques containing ab40/42 APP fragment
Tau proteins
bind to microtubules and act as spacers to keep MT bundles in parallel
dissociate if instable MT or hyperphosed
form aggregates
APP
transmembrane protein–>cleaved by secreatses (B & gama together)–>decrease synapse formation and release frag into extracellular space
frag is AB40/42 = NOT toxic
gama secretase
complex of protein subunits
4 main proteins
-presnilin, nicastrin, aph1, pen2
reside in lipid rafts, so gama secretease is influenced by cholesteral levels
AB aggregation
- accumulation of amyloid containing plaques
- inflammatory via activated microglia and astrocytes
- altered axonal transport (due to tau)
- altered synaptic activation
- altered intracellular Ca
treatements of altz
acetycholinesterase inhibitors (talcrine)–>prolong and enhance Ach levels
small molec inhibitors–>prevent AB aggregation
antibodies against amyloid protein
Parkinson’s Disease
loss of DA neurons in substantia nigra
Lewy bodies in neurons
lewy bodies
protein aggregates that include a-synuclein & ubiquitin
mech parkinsons
genetic mutations–>misfolded proteins–>toxic effects
lewy bodies-
- evidence for accumulation of proteins
- evidence for cell attempt to protect itself by sequestering toxic proteins
-mutations in genes encoding parkin and uchl-1 (proteins involved in delivery of proteins to pretasome for degradation)
current therapy categories of altz
- reagents to prevent progression
- replacement of NT
- re-balance of neuronal circuits
- virus mediated gene delivery
- prevent or slow loss of neurons using neutrophic factors
- transplantation