Flashcards in Cell Death and immunological implications Deck (95)
What are the functions of cell death in normal circumstances?
tissue homeostasis; embryogenesis; cell turn-over
What is type I cell death?
What characterises apoptosis?
nuclear fragmentation; shrinkage and membrane blebbing
what is type II cell death?
What are the features of autophagy?
extensive cytoplasmic vacuolization and lysosomal degradation
What is type III cell death?
What is necrosis?
an accidental death that causes damage
What are the features of necrosis?
passive; accidental:trauma; infections; swelling and loss of membrane integrity; evidence of inflammation
When may apoptosis cause inflammation?
end-stage apoptosis can have membrane pore formation and thus inflammation
What is seen in early apoptosis?
membrane relatively intact, exposure of phophatidylserine
what is karyorrhexis?
What is pyknosis?
What are hte morphological characteristics of apoptosis?
plasma membrane blebbing; mitochondrial depolarisation; nuclear and cytoplasmic condensation; apoptotic bodies
What is a biochemical marker of apoptosis?
phosphatidylserine flipping- changes from inner to outer leaflet of hte plasma membrane
How can DNA fragmentation be measured in the lab ?
DNA laddering- electrophoresis; DNA strain breaks by TUNEL assay
What is the difference between the caspase induced in intrinsic vs extrinsic pathways?
intrinsic pathway: caspase-9 and caspase 3; extrinsic pathway- caspase 8
What is necroptosis?
caspase-independent cell death
What protein does necroptosis rely on?
RIP1 kinase 3 (receptor interacting protein)
What receptors trigger necroptosis?
death receptors eg TNFR1
What events can trigger necroptosis?
inflammation; ischaemia-reperfusion injury; thrombosis
What is the inflammasome?
a pro-inflammatory protein formed after stimulation of NOD-like receptors, production of an active caspase in the complex processes cytokine proproteins into active cytokines
What triggers ferroptosis?
intracellular pertubation notably lipid peroxidation
Waht is ferroptosis characterised by?
iron dependent production of reactive oxygen species
Does ferroptosis rely on caspases?
What process in ferroptosis invovled in?
glutamate toxicity on neuron
What is pyroptosis characterised by?
cellular swelling and plasma membrane permeabilisation due to gasdermin protein family
What are the similarities and differences between pyroptosis and necrosis?
both are very inflammatory however pyroptosis is controlled and the cell doesn't burst
When doe spyroptosis arise?
after canonical and non-canonical activation of hte inflammasome (caspase 1, 3, 4 and 11)
What is found in the cytoplasmic domains of cytokine receptors?