The Mechanisms Of Cell Death Flashcards
(19 cards)
Necrosis
• Always pathological
• Affects adjacent group of cells
• Passive
• Causes inflammatory reaction
• Cell size is increased
• Plasma membrane is distrupted
• Denaturation of intracellular proteins,
• Leakage of celluar contents through damaged
membranes
• Enymatic digestion in the lethally injured cell
digestion of the cell by catalytic enzymes
secreted by itself
Autolysis
digestion of the cell by catalytic enzymes
secreted by surronding leucocytes
Heterolysis
Morphological changes in necrotic cells
Nucleus: Three different patterns depending on distruption of
DNA
• Pyknosis
• Karyorrhexis
• Karyolysis
• Cytoplasm:
• Eosinophilic
• Homogeneous
• vacuolated
Morphological patterns of necrosis
• Coagulation Necrosis
• Liquefaction necrosis
• Caseous necrosis
• Fat necrosis
Apoptosis
• Programmed cell death
• Physiological or pathological
• Affect single cells
• Active
• No inflammatory reaction
• Cell size is shrunken
• Plasma membrane is intact
• A pathway of cell death
• Cells activate intrinsic enzymes
• The enzymes degrade the cells’ own nuclear DNA and nuclear and
cytoplasmic proteins
• Apoptotic cells break up into fragments
• apoptotic bodies, which contain portions of the cytoplasm and nucleus.
• Plasma membrane of the apoptotic cell and bodies remains intact
• But its structure is altered
• These become ‘’tasty’’ targets for phogocytes
• Cellular content does not leak out
• There is no inflammatory response
Apoptosis requires
ATP
Phases of apoptosis
Signaling phase
Execution phase
Degradation phase Apoptptic bodies
Phagocbytic phase
Mechanism of apoptosis depends on caspase enzymes via two pathways
Mitochondrial (intrinsic) pathway
Death receptor (extrinsic) pathway
Cytochrome c çıkışı varsa
Apoptosis
BCL2, BCXL, MCL1
anti-
apoptotic
BAX and BAK
Pro apoptosis
BH3 senses …..
And activate …..
Damage
BAX BAK
The Death Receptor
(Extrinsic) Pathway of
Apoptosis
• ligand-binding
• death receptorsg on
the cell surface
• tumour necrosis
factor receptor
(TNFR) gene family
• TNFR1
factor receptor
(TNFR) gene family
• TNFR1 and Fas
(CD95)
• Fas ligand expressed
mainly on activated
T lymphocytes
• Ligand binding
• clustering of receptor
molecules on the cell
surface
• initiation of a signal
transduction cascade
• activation of caspases
Normal hücre zarında phosphatidilserine …..
Apoptotic body de ………
İçte
Dışta fagosiztozlar tanır
FLIP
Caspaselerin aktivasyonunu engeller
DNA damaged ……. Birikir
P53
Pyroptosis release of
Fever induced
Ng cytokine IL1
Ferroptosis
Glutathione dependent antioxidant defenses
