chapter 18 apoptosis apoptosis is only one form of programmed cell death. in animal cells, cell...
TRANSCRIPT
![Page 1: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/1.jpg)
Chapter 18
Apoptosis
Apoptosis is only one form of programmed cell death.
In animal cells, cell necrosis is another form of programmed cell death.
![Page 2: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/2.jpg)
Two distinct forms of cell death – apoptosis and necrosis
Programmed cell death eliminates unwanted cells
![Page 3: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/3.jpg)
In metazoans, apoptosis is vital for- normal development- maintenance of tissue homeostasis- an effective immune system
Its disturbance is implicated in numerous pathological conditions ranging from degenerative disorders to autoimmunity to cancer
Sculpting the digits in the developing mouse paw by apoptosis
![Page 4: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/4.jpg)
Apoptosis during the metamorphosis of a tadpole into a frog
![Page 5: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/5.jpg)
Apoptotic cells are biochemically recognizable
Characteristic biochemical changes in cells undergoing apoptosis
1. Chromosomal DNA cleaved into fragments 2. Change in the plasma membrane – phosphatidylserine
in the outer leaflet3. Loss of electrical potential across the inner membrane of the
mitochondria4. Relocation of cytochrome c from the intermembrane space of
the mitochondria to the cytosol
![Page 6: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/6.jpg)
Cleavage of chromosomal DNA into a characteristic ladder of fragments
![Page 7: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/7.jpg)
Apoptosis depends on an intracellular proteolytic cascade that ismediated by caspases
Procaspase activation during apoptosis
![Page 8: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/8.jpg)
Some human caspases
Caspases involved in inflammation caspases 1 (ICE), 4, 5
Caspases involved in apoptosisInitiator caspases caspases 2, 8, 9, 10Executioner caspases caspases 3, 6, 7
Examples of target proteinsNuclear laminsProtein that holds the endonuclease in an inactive stateComponents of the cytoskeleton and cell-cell adhesion proteins
![Page 9: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/9.jpg)
![Page 10: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/10.jpg)
The two best understood signaling pathways that activate acaspase cascade in mammalian cells are the extrinsic pathway and the intrinsic pathway
Each pathway uses its own initiator procaspasesand activation complex
![Page 11: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/11.jpg)
Cell-surface death receptors activate the extrinsic pathway of apoptosis
The extrinsic pathway of apoptosis activated through Fas death receptors
![Page 12: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/12.jpg)
The intrinsic pathway of apoptosis depends on mitochondria
![Page 13: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/13.jpg)
Release of cytochrome c from mitochondria during apoptosis
![Page 14: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/14.jpg)
Bcl2 proteins regulate the intrinsic pathway of apoptosis
The three classes of Bcl2 proteins
![Page 15: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/15.jpg)
The three major mammalian factions of the Bcl-2 family. The BH3-only proteins (yellow) are essential initiators of apoptosis that primarily antagonize their pro-survival relatives (blue), whereas either Bax or Bak (red) is required downstream of Bcl-2.
![Page 16: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/16.jpg)
The role of BH123 pro-apoptotic Bcl2 proteins (mainly Bax and Bak) in therelease of mitochondrial intermembrane proteins in the intrinsic pathway of
apoptosis
![Page 17: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/17.jpg)
How pro-apoptotic BH3-only and anti-apoptotic Bcl2 proteins regulate the intrinsic pathway of apoptosis
![Page 18: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/18.jpg)
IAPs inhibit caspases
A proposed model for the rolesof IAPs and anti-IAPs in thecontrol of apoptosis inmammalian cells
![Page 19: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/19.jpg)
Extracellular survival factors inhibit apoptosis in various ways
![Page 20: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/20.jpg)
Three ways that extracellular survival factors can inhibit apoptosis
![Page 21: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/21.jpg)
Either excessive or insufficient apoptosis can contribute to disease
![Page 22: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/22.jpg)
![Page 23: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/23.jpg)
![Page 24: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/24.jpg)
![Page 25: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/25.jpg)
![Page 26: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/26.jpg)
![Page 27: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/27.jpg)
![Page 28: Chapter 18 Apoptosis Apoptosis is only one form of programmed cell death. In animal cells, cell necrosis is another form of programmed cell death](https://reader035.vdocuments.us/reader035/viewer/2022062300/56649db05503460f94a9ed12/html5/thumbnails/28.jpg)