Flashcards in Cell Death Deck (40):
What can happen to mitochondria during reversible cell injury and what can this lead to?
Mitochondrial swelling and calcification leading to oxygen depletion & toxication
Will the endoplasmic reticulum constrict or dilate during cell injury?
What will happen to ribosomes during reversible cell injury?
Ribosomes will become disaggregated
What is typical of lethal cell injury?
Inflammation ---> necrosis
Where can coagulative necrosis be observed?
Most tissues (firm pale area with ghost outlines)
Where can colliquative necrosis be observed?
In the brain (dead area is liquified)
Where can caseous necrosis be observed?
In tuberculosis (pale yellow semi-solid material)
Where can fibrinoid necrosis be observed?
Arterioles in malignant hypertension
Where can fat necrosis be observed?
Following trauma or following pancreatitis
What is gangrene?
Necrosis with putrefaction
Name some causes of necrosis.
How does Programmed Cell Death (PCD) differ from Apoptosis?
Apoptosis is morphological (has a set structure and form that it takes in breaking down each cell, regardless of what cell type it is
Give three examples of apoptosis.
Embryology and formation of lumen of tubes
Response to growth signals including the menstrual cycle
Inflammation including its resolution and the death of neutrophils
Immune defence - T and NK cell responses
Tumour prevention - prevent mutation
Autoimmune diseases and their self destructing nature
Does apoptosis target single cells, tissues, or organs?
How does apoptosis target the heart of the cell?
Involves DNA fragmentation
How does extrinsic apoptosis differ from intrinsic apoptosis?
Activation of apoptosis is from outside the cell in extrinsic apoptosis whereas in intrinsic apoptosis, it it from the inside of the cell
Name some examples of intrinsic apoptosis.
Stress (e.g. oxidative)
Cytochrome c leaks from mitochondrion causing caspase enzyme cascade
Name some examples of extrinsic apoptosis.
T-cell immune response
TNF family binds to reeptor, activating caspase enzyme cascade
What is the function of p53?
p53 can tell a cell to repair itself, grow, or undergo apoptosis (via induced reverse transcriptase factor)
How are the apoptotic fragments/bodies carried away from the site of apoptosis?
Macrophages or non-professional phagocytes (e.g. epithelial cells) recognise the fragments and immediately ingest them
What is the function of the bcl-2 family of proteins?
Regulate cell death
What types of bcl-2 family proteins are there?
What effect do Bcl2 proteins have on apoptosis?
Inhibit (anti) apoptosis
What effect do BH123 proteins have on apoptosis?
Allow (pro) apoptosis
What effect do BH3 protein have on apoptosis?
Allow (pro) apoptosis
Give some example of Bcl2 proteins.
Give some examples of BH123 proteins.
Give some examples of BH3 proteins
What can abnormal (over-) expression of Bcl2 lead to?
What effect does IAP have on apoptosis?
What are Caspases?
Have cysteine in their active sites 'C'
Cleavage after aspartate 'asp'
Are proteases 'ase'
What do caspases do?
Cleave ICAD (destroy genetic information)
Cleave PARP (prevent DNA repair)
Cleave lamin (break down nuclear architecture)
Cleave keratin (break down cytoplasmic architecture)
What three factors can increase survival chances of a cell?
Bcl2 production increased (anti-apoptotic)
Inactivation of BH3 (pro-apoptotic)
Anti-IAP inactivation (IAP is anti-apoptosis, so destruction of anti IAP ---> decreased apoptosis
Which component can lymphoma target and disable?
Which component can Alzheimers Disease target and disable?
Which component can cancer target and disable?
Name three things that can happen when apoptosis goes wrong
What is pyroptosis?
Highly inflammatory form of PCD that is commonly a response to infection by intracellular pathogens
Which 'features' of apoptosis are also present in necrosis?
Caspase 1 activation (NOT caspase 3)
Nuclear fragmentation (NOT cytoplasmic blebbing)