Apoptosis

Question 1

true or false apoptosis is highly conserved

Answer 1

true

Question 2

what is apoptosis crucial for

Answer 2

development
maintenance
control

Question 3

what can occur when apoptosis is overreactive

Answer 3

Neurodegeneration
Immunodeficiency
Stroke
Transplant Rejection

Question 3

what can occur when apoptosis is under reactive

Answer 3

Neurodegeneration
Immunodeficiency
Stroke
Transplant Rejection

Question 4

what can occur when apoptosis is overreactive affecting the life-death balance

Answer 4

Allows cell accumulation (e.g. accumulation of cells during an immune response)

Question 5

what can occur when apoptosis is under reactive affecting the life-death balance

Answer 5

Returns cell populations to normal after challenge
Neutrophil apoptosis during inflammation

Question 6

phases of apoptosis

Question 12

describe the Cleavage of caspase substrates in Apoptosis

Question 13

what is the extrinsic pathway

Answer 13

Cell are instructed to die from outside
Receptors (“Death Receptors”) on cell surface induce death when ligated

Question 14

what is the intrinsic pathway

Answer 14

Intracellular Insults can induce

Question 15

why are apoptosis molecules important

Answer 15

important in recruiting initiator caspases and allowing their activation

Question 16

Intrinsic Pathway-mediated cell death

Question 17

Extrinsic Death Receptor-mediated cell death

Question 18

SELF STUDY

Question 23

Extrinsic Death Pathway & Disease

Question 24

explain the Control of cell death – Bcl-2 family

Answer 24

Family of interactive proteins

Protect from apoptosis – Pro-survival
Suppress protection – Pro-death

Pro- death and pro-survival members

Bcl-2 - prototypic member of the family

Question 25

describe the Bcl-2 family and their roles

Question 26

Apoptosis disrupts mitochondria (BH123 members)

Question 27

Bcl-2 prevents mitochondrial disruption

Question 28

BH3 only proteins inhibit Bcl-2 & tip the balance

Question 29

explain how CELL STRESS can affect the control of apoptosis

Answer 29

DNA (genotoxic) damage stabilizes p53 > production of BH3 only members (Bad, Bid, Noxa, Puma)
= PRO-DEATH

Question 30

explain how IAPs can affect the control of apoptosis

Answer 30

Inhibitors of Apoptosis (inhibit caspases = anti- death)
produced by some viruses to prevent death
Over-expressed in some cancers

Question 31

explain how Too little apoptosis INCREASED risk cancer

Answer 31

cells don’t die and accumulate
cancer fails to respond to treatment
malignant cells fail to die in response to
->chemotherapy
->immune surveillance (e.g. by T cells and NK cells)

Question 32

what are the different levels of Cell death machinery can be inactive

Answer 32

Over-expression of anti-apoptosis genes
Modulation of caspases
Mutation of pro-apoptotic genes
Alteration of cell death regulators

Question 33

what can occur when there is an Over-expression of anti-apoptosis genes bcl-2 and follicular lymphoma

Answer 33

Chromosome 18
Translocated to chromosome 14 close to Ig heavy chain enhancer →high expression
Suppression of apoptosis → lymphoma
T(14:18) characteristic of follicular lymphoma

Question 34

what can occur when there is an Over-expression of anti-apoptosis genes c-myc gene (cell cycle)

Answer 34

Chromosome 8
Translocated to chromosome 14 close to Ig heavy chain enhancer → high expression
Proliferation of cells

Question 35

what can occur when there is an Over-expression of anti-apoptosis genes c-myc and bcl2

Answer 35

speed the formation of lymphoma

Question 36

are all pro-survival Bcl-2 family members predicted to be oncogenes

Answer 36

yes