2. Apoptosis
A form of cell death in which a programmed sequence of
events leads to the elimination of cells without releasing
harmful substances into the surrounding area.
Therefore does not elicit inflammatory reaction
9. Death of host cells that have served their useful purpose
10. Apoptosis in pathologic
conditions
DNA Damage
Accumulation of Misfolded
proteins
Cell injury in certain infections
Pathologic atrophy in parenchymal
organs after duct obstruction
11. Mechanism of Apoptosis
Intrinsic pathway :the
cell kills itself
because it senses cell
stress,
Extrinsic pathway the
cell kills itself
because of signals
from other cells.
12. Main executors of the apoptotic process is . . ?
• CASPASES
• They stands for Cysteine
Aspartate-specific Protease
• Synthesized as inactive zymogens
(PROCASPASES)
15. 1. Withdrawal of survival
factors
2. Direct mitochondrial
3. ER stress
4. p53-mediated
5. Viruses
BH3
SENSORS
31. Apoptosis of
Self-Reactive
Lymphocytes
Lymphocytes capable of recognizing self
antigens are normally produced in all
individuals.
If these lymphocytes encounter self
antigens, the cells die by apoptosis.
Both the mitochondrial pathway and the
Fas death receptor pathway
Failure of apoptosis of self-reactive
lymphocytes is one of the causes of
autoimmune diseases.
Apoptosis plays a crucial role in developing and maintaining the health of the body by eliminating old cells, unnecessary cells, and unhealthy cells. The human body replaces perhaps one million cells per second. Too little or too much apoptosis can play a role in many diseases. When apoptosis does not work correctly, cells that should be eliminated may persist and become immortal, for example, in cancer and leukemia. When apoptosis works overly well, it kills too many cells and inflicts grave tissue damage. This is the case in strokes and neurodegenerative disorders such as Alzheimer's, Huntington's, and Parkinson's diseases
Cyt c helps in cellular respiration in mitochondria but when it comes out in the cytosol it takes the cell in apoptosis
Cytochrom c binds to Apaf 1 protein that form a structure call aposome