The document discusses apoptosis or programmed cell death. It provides background on the history of apoptosis, definitions, key morphological changes, major players involved like caspases and Bcl-2 proteins, and the two main pathways of apoptosis - the intrinsic mitochondrial pathway and extrinsic death receptor pathway. Detection methods for apoptotic cells are also covered, including electron microscopy, DNA fragmentation analysis, TUNEL assay, and flow cytometry. Therapeutic implications for targeting apoptosis in diseases like cancer, neurodegeneration and myocardial infarction are also mentioned.

1. 1

2. The history of Apoptosis
 What Apoptosis means
 Significance of Apoptosis.
 Morphological changes
 Major players in apoptosis.
 Pathways to apoptosis
 Therapeutic implications.
 Pathological implication
 Detection of apoptotic cells
2

3. The History of Apoptosis
John Kerr:
a Brisbane pathologist in 1972
introduced a concept ‘Apoptosis’.
(Richardson, et al., 2000)
3

4. Synonyms: - Antonym: -
Programmed cell death. Necrosis
Programmed cellcell death are of two types: -are of two types: -
Apoptosis : -(Type I)
Autophagic : -(Cytoplasmic, or Type II)
The formation of large vacuoles that eat away organelles
before the nucleus is destroyed.
(Offermanns & Rosenthal , 2004)
4

5.  Greek origin word known ‘Falling off or Dropping off.’
 Self destruction programmed genetically sequenced in
biomedical events.
 It’s a kind of counterbalance by elimination of similar
number of cells.
 Death by design.
Apoptosis: -
(Rang & Dale, 2008)
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6. Significance of Apoptosis
 Deletion of dangerous & damage cells.
 Development of organs
 Without apoptosis human
gut can grow 19 km,whole
epithelial lining changes every
23 days.
 Regulation of immune system(T-cells)
Incomplete differentiation
due to lack of apoptosis
 Cancer & Neurodegenerative diseases.
(Gewies, 2003)
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7. Apoptosis Necrosis
• Energy dependent PCD • Cell dies due to damage
• One cell • Group of cells
• No inflammation • Acute inflammation
• Role of mitochondria • No role of mitochondria
• Dead cells eaten by
macrophages
• Dead cells removed by
macrophages.
• Cell shrinkage • Cell swelling
(Haiat, 2006)
7

8. The Apoptotic Cell
8

9. Morphological changes in Apoptosis
(Hengartner, 2000)
9

10. Major players in Apoptosis
Apoptosis Initiating factor(AIF):-
Release from mitochondria enter in
nucleus & trigger cell suicide.
Caspases
Bcl-2 Proteins
 Apoptosome
 p53 gene and p53 protein
(Rang & Dale, 2008)
10

11. • It is family of cystein protease.
• present in cell in inactive form.
• Cleave protein bearing a amino acid
sequence located at the terminal.
(cystein aspartic acid specific protease)
(Hill,et al., 2003)
11

12. Caspases
14 different Caspases14 different Caspases
Initiator
Caspases
Effectors
Caspases
2,8,9,10.2,8,9,10.
3,6,7.3,6,7.
12

13. 13

14. Apoptosis carried out by Caspases
(Susin, et al., 1999)
14

15. CARD/DED
Domain
Large subunit
Small subunit
Procaspase Structure
15

16. Caspase
activation
Inactive
Procaspase
Proteolysis
cleavage
Activation of
Caspase
Initiator Caspase
16

17. Active Initiator
Caspase
Cleavage by protein-protein
interaction
Activation of
effector caspase
Caspase
activation 17

18. The Bcl-2 Family
 Regulator Protein of Mitochondria.
 Isolated from gene involve in B-cell lymphoma.(Bcl-2)
 All have BH3 domain (Bcl-2 Homology)
BH3:-It is Proapoptotic domain expose on activation.
(Dash, et al., 2001)
18

19. Bcl-2 family members:-
 BH1-4: - Anti-apoptotic proteins
Bcl-2, Bcl-xL .
 BH1-3: - Pro-apoptotic proteins
Bax, Bok, Bak.
 BH 3: - Only pro-apoptotic proteins
Bad, Bik, Bid.
Bcl-2: -ß-cell Lymphoma, BH:-Bcl-2 Homolog, Bid: - Bcl-2 interacting
domain, Bcl-xL :- x=Close homolog & L= inhibit apoptosis.
19

20. Functions:-
 Regulate the balance between Pro-Apoptotic &
anti-apoptotic.
 Involved in Intrinsic pathway.
 Induction of Bcl-2 is by death signals.
20

21. Apoptosome
 Multisubunit protease activation complex.
 Form after induction of death signal in mitochondrial
pathway.
 Discovery of Apoptosome by ‘prof. Wang’.
 Wheel-like structure connected to seven radial spokes
(Adrain, 2001; Dash, 2003)
21

22. Active caspase
Apoptic
stimuli
Apoptic
stimuli
Cytochrome-c
Binding
Apaf-1
22

23. Apoptotic activation
protease factor-1
Apoptotic activation
protease factor-1
23

24. p53 gene & p53 protein
 p53 is a tumor suppressor gene.
 Prevent completion of cell cycle.
 If DNA damage occurs activation of gene p53 response to
cell death.
 Curable damage can be repaired
 In curable damage of DNA leads to cell death
(Dlamini et al.,2005)
24

25. Pathways to Apoptosis
1) Death receptor pathways /(Extrinsic Pathway)
2) Mitochondrial pathways /(Intrinsic Pathway)
25

26. Death receptor pathways /(Extrinsic Pathway)
 Induction is mediated through cell surface receptors
know to be ‘Death receptors’.
 Death ligands are activating these receptors.
 Further activation of Caspases leads to cell death
(Rang & Dale, 2008)
26

27. Death Receptors
TNFR - Super family
TNFR-Tumor necrosis factor Receptor, CD: -Cluster differentiation
TRAIL- Tumor necrosis factor –α related apoptosis inducing ligand
Fas:- Apoptosis stimulating fragment.
Death receptorDeath receptor Death ligandsDeath ligands
 TNFR-1
 CD95 (Apo-1) (Fas) (TNFR-2)
 TRAIL-R1 (DR-4)
 TRAIL-R2 (DR-5)
TNF-α
CD95L (FasL)
TRAIL-R1
TRAIL-R2
(Ashkenazi, 2002)
27

28. TNF Receptor signaling
Binding of Ligand
to Death receptor
Binding of Ligand
to Death receptor
Binding of adapter
protein with
Activation of
Another protein
TRAF-2
Binding of adapter
protein with
Activation of
Another protein
TRAF-2
TRAF-2: -TNF associated factor -2,
TRADD:- TNF associated death domain,
28

29. Fas:- Apoptosis stimulating fragment ., FADD:- Fas Associated death domain
Adapter Protein
Fas signaling pathway
29

30. Death receptors signal transductionDeath receptors signal transduction
Effectors domain
30

31. The Extrinsic Apoptosis Pathway
FADD, Fas-associated death domain, DR:- Death receptors.
Pro-apoptotic ligands
Caspase 3, 6, 7
Apoptosis
FADD
DR5
DR4
Procaspase 8, 10
Caspase 8, 10
Plasma
membrane
(Ashkenazi A. Nat Rev Cancer 2002;2:420–430.)
31

32. Macrophage release anti-inflammatory mediators like
[transforming growth factor(TGF-ß] & IL-10]
Macrophage undergo phagocytosis of cell
32

33. Mitochondrial pathways /(Intrinsic Pathway)
 Release of protein from mitochondrial inner membrane
into cytosol.
 DNA damage induce apoptosis.
 Cellular stress, heat shock, oxidative stress, cellular
damage, that are also induced apoptosis.
(Martin, et al., 2003)
33

34. Plasma
membrane
Cytosol
DNA
Damage
P53 proteinP53 protein
Pro-apoptic Bcl-2
Mitochondria
Apaf-1
Cytochrome-c
Procaspase-9 34

35. Caspase-9Caspase-9
Caspase-3Caspase-3
Activation
35

36. APOPTOSIS
Video
(http://www.researchapoptosis.com) 36

37. Apoptosis By Injury
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38. Pathological Implications
 Growth of tissue & organs in embryo.
 Replenishment of time-expire cells like gut-epithelium.
 Repair & healing after injury or inflammation.
 Regeneration of tissue.
 Hyperplasia.
(Barton, et al., 2004)
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39. Therapeutic implications
 Neurodegenerative disease like Alzheimer’s disease.
 Myocardial infraction.
 Targets for anti-cancer drugs.
(Gerald, 2002)
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40. Neurodegenerative disease: -Neurodegenerative disease: -
 Alzheimer’s disease show excessive Apoptosis.
 Neuronal growth factor & brain derived
neurotrophic factors.
 Secrets protein that maintain the balance Pro-
Apoptotic & Anti-Apoptotic.
 Blocking of these factor are new area of interest for
Target drug delivery.
 Alzheimer’s disease show excessive Apoptosis.
 Neuronal growth factor & brain derived
neurotrophic factors.
 Secrets protein that maintain the balance Pro-
Apoptotic & Anti-Apoptotic.
 Blocking of these factor are new area of interest for
Target drug delivery.
(Gerald, 2002)
40

41. Apoptotic Neuron
41

42. Myocardial Infraction: -Myocardial Infraction: -
 Occur due to blockage of coronary artery by
thrombus.
 Decrease in oxygen supply leads to (M.I.) by necrosis
or Apoptosis
 Two pathways of cell death
1) Necrosis 2) Apoptosis
(Rang & Dale, 2008)
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43. Current approach are finding to
inhibit these pathway which are
beneficial in clinical
43
ICE:-interleukin -1 converting enzyme.
PARP:- (poly-ADP-ribose-polymerase .

44. Targets for Anti-cancer drugs: -Targets for Anti-cancer drugs: -
 Bcl-2 family as a target for new drug.
 Bcl-2 is Anti-apoptotic & increase resistance to
cancer chemotherapy.
 Death receptor & there respective ligands are useful
in targeting the Anti-cancer drug.
(Fischer, et al., 2005)
44

45. How do we recognize Programmed Cell
Death?
45

46. Detection of apoptic cells
 Electron Microscopy
 Fluorescence Microscopy
 Staining with Eosin
 Detection of PCD Based on Morphology
 Detection of DNA Fragmentation
 Agarose Gel Electrophoresis
 DNA Fragments by Cell Fractionation
 Detection of DNA Fragmentation by Filtration Assay.
(Kaufmann, 2000)
46

47.  Terminal Deoxyribonucleotidyl Transferase-Mediated
dUTP Nick End Labeling.(TUNEL)
 Flow Cytometry.
 Enzyme Assay.
47

48. Detection Based on Morphology: -Detection Based on Morphology: -
 Shrinkage of the cell.
 Detachment from its neighbors.
 Fragmentation of nucleus.
 Packaging of the cell into multiple plasma
membrane.
 Phagocytosis of these fragments.
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49. Control Apoptotic cells
49

50. Electron Microscopy: -
 A beam of electron using electric & magnetic field
to form enlargement of image on photographic
plate.
50

51. Electron Microscopy: -
51

52. Detection of DNA fragmentation by Gel
Electrophoresis.
Detection of DNA fragmentation by Gel
Electrophoresis.
 Agarose gel with suitable separation properties.
 Application of total cellular DNA to an Agarose.
 The fragments are spared throughout agarose gel.
 Fragments will be detected by Ethidium bromide.
(Anders, 2002)
52

53. 1. DNA from apoptotic cells.
2. DNA isolated from necrotic
cells
3. No samples
4. DNA from normal cell
5. DNA from normal cell
6. No sample
Gel Electrophoresis
53

54. Flow CytometryFlow Cytometry
 Well known as a ‘Flow Microfluriometer.
 To study Normal & Malignant Lymphocytes.
 Measures amount of fluorescence associated with cell.
 Photomultiplier tube is a detector.
 Analyzing the population of cell.
 Around 20,000 cells can be analyzed in few min.
(Kaufmann, 2000)
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55. 55
http://www.kimmelcancercenter.org
Flow Cytometry

56. 56
Advance Flow
Cytometry
Advance Flow
Cytometry
http://www_biotech_missouri_edu

57. Adrain, C. Martin, S.J. 2001 The mitochondrial apoptosome: A killer
unleashed by the cytochrome seas. Trends Biochem. Sci. 26, 390–397.
Ashkenazi, A.Dixit, V. M., 1999. Apoptosis control by death and decoy
receptors. Current Opinion in Cell Biology 11, 255-60.
Dash, P., 2001. Apoptosis Basic Medical Sciences
St.George’s, University of London
Fischer, U.OsthofF, K. S., 2005. New Approaches and Therapeutics
Targeting Apoptosis in Disease: Pharmacological reviews, 57 (2), p.187-
215.
Hill, M.M. Adrain, C. Martin S.J., 2003.Molecular Cell Biology
Laboratory, Department of Genetics Smurfit Institute, 3 (1) p.19-24.
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58. Gewies, A., 2003. Introduction to Apoptosis :Apo Review p.1-26
Hill, M. M.Adrain, C., 2003. Portrait of the killer the mitochondrial
Apoptosome emerges from the shawdo:molecular intervention. 3
(1)p.19-24.
Kaufmann, S.2001. Apoptosis:Phaarmacological implication and
therapeutic opportunites.New York: Academic Press
Li, L.Y., Luo, X. Wang, X., 2001 Endonuclease G is an apoptotic
DNase when released from mitochondria. Nature 412, 95–99.
Margaret, K.T. Cohen, J., 2001. Standard Quantitative Assays for
Apoptosis: Molecular Biotechnology, 19 p.305-315
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59. Offermanns, S. Rosentha, W., 2004. Encyclopedic Reference of
Molecular Pharmacology,Springer
Rang, H. P. Dale, M. M., 2008.Cell proliferation and Apoptosis:
Pharmacology.6th
ed.Churchill Livingstone Elsevier.p.72-88.
http://www.researchapoptosis.com
http://www.apoptosisinfo.org
http:// www.bitessizebio.com
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