What is apoptosis Apoptosis is a morphological term

What is apoptosis? ? • Apoptosis is a morphological term • Apoptosis and programmed cell death frequently are used interchangeably • Apoptotic death is characterized by: nuclear condensation membrane blebbing phosphotidylserine flipping DNA degradation into nucleosomal fragments new gene synthesis in some instances

Morphological features of apoptosis Normal thymocyte Apoptotic Thymocyte (induced to die by Dex) Transmission EM Scanning EM

Apoptosis Involves Biochemical As Well As Morphological Changes Figure 9. 18 a The Biology of Cancer (© Garland Science 2007)

Not in all cases Table 9. 3 The Biology of Cancer (© Garland Science 2007)

Figure 9. 19 The Biology of Cancer (© Garland Science 2007)

Apoptosis plays a key role in regulating lymphocyte cell numbers

How do we get rid of corpses? ? Why do we get rid of corpses? ?

Find me and eat me signal and phagocyte receptors Lorenz & Ravichandran LPC = lipid lysophosphatidylcholine

Engulfment of apoptotic cells requires cytoskeletal rearrangment Lorenz & Ravichandran

Induction of Apoptosis – an Overview

The Apoptosome Figure 9. 28 The Biology of Cancer (© Garland Science 2007)

Caspases must be cleaved to be activated Caspase family tree** **There are now at least twelve caspases

Initiator & Effector Caspases

Induction of Apoptosis – an Overview

The Bcl-2 Family – Key Modifiers of Apoptosis Figure 9. 25 a The Biology of Cancer (© Garland Science 2007)

Bcl-2 family members play an important role in many life and death decisions * *

Figure 9. 27 c The Biology of Cancer (© Garland Science 2007)

Influence of anti-Apoptotic Gene on Outcome of Oncogene Challenge Engineering the Mice Influence of Cooperation on Survival

Exrinsic and Intrinsic Death Pathways

Death Receptors of the Extrinsic Pathway Figure 9. 31 a The Biology of Cancer (© Garland Science 2007)

Figure 9. 33 The Biology of Cancer (© Garland Science 2007)

Figure 9. 34 The Biology of Cancer (© Garland Science 2007)