Apoptosis Flashcards
apoptosis is not an _____ (unlike necrosis)
inflammatory process
what are the physiological situations in which apoptosis occurs
embryogenesis and involution of hormone-dependent tissues upon hormone withdrawal
what are the pathological situations in which apoptosis occur
irreversible DNA damage (mutations, radiation, and hypoxia), accumulation of misfolded protein, and certain viral infections.`
nuclear margination
chromatin condensation
on H&E stains apoptotic cells appear
intensely eosinophilic / shrunken basophilic, surrounded by halo
caspases
enzymes that when activated lead to apoptosis
what are the types of caspases
initiators (caspase 8 & 9) and executioners (caspase 3 & 6)
what are the anti-apoptotic proteins
Bcl-2 (most imp), Bclx, and Mcl-1
what are the pro-apoptotic proteins
Bak and Bax
what stimulates the production of anti-apoptotic proteins
Growth factors
which pathway is the major mechanism of apoptosis
mitochondrial pathway (intrinsic)
BH3
inhibits anti-apoptotic and activates pro-apoptotic
mitochondrial pathway
- release of cytochrome C from the mitochondria into the cytosol
- Cytochrome C binds to Apaf-1 (apoptosis activating factor) forming apoptosome
- apoptosome binds to caspase-9
caspase-9
the critical initiator caspase
which pathway is responsible for the elimination of self-reactive lymphocytes
death receptor pathway (extrinsic)