Cell Injury Flashcards
What is hypoxic stress?
Lack of oxygen in tissues caused by ischaemia
What is oxidative stress?
High concentrations of reactive oxygen species
What is proteotoxic stress?
When conditions in the cell cause proteins to denature e.g. fever, toxins, oxidants and hypoxia
What is ER stress?
When protein synthesis is unbalanced
What is genotoxic stress?
When DNA is damaged
What are the consequenes of ER stress?
Inflammation
Type 2 diabetes
Protein misfolding disorders
What are active responses to stress?
Transcription of genes to encode protective proteins to allow cell to adapt to stress
What are passive responses
Uncontrolled ion flux which causes cell lysis
What is the proteotoxic stress response
HS1 activates genes coding for heat shock proteins which promote the folding, transport and degradation of denatured proteins
What is the ER stress response?
Halts protein translation
Degrades misfolded proteins
Induces production of chaperones to increase protein folding
Induces apoptosis
What is the hypoxia response?
Induces proteins active in glucose transport, glycolysis
Increases EPO and blood vessel development using VEGF
What is the response to oxidative stress?
Increase antioxidant production
What is the response to DNA damage?
Activates p53 to arrest cell cycle and induce DNA repair
What happens during apoptosis?
Death receptors activated
Egress of cytochrome C
Apoptosome activates initiator caspases which activates effector caspases which cleave proteins
What is necrotic cell death?
Occurs after ischaemic injury, MI, stroke or infection
