Download - A Pop to Sis Final
-
8/8/2019 A Pop to Sis Final
1/39
Group 3 Section C2
Paraguya, Lanisa
Parias, Orlando IIPasajol, Margarita
Pascua, Vanessa
-
8/8/2019 A Pop to Sis Final
2/39
To define Apoptosis
To differentiate apoptosis from necrosis
To determine the different cellular features
of both apoptosis and necrosis
To discuss the role of apoptosis in
embryogenesis, development and
differentiation of tissues, AIDS, Cancer and
immune defense
To discuss the different laboratory indices
that will define cells undergoing apoptosis
-
8/8/2019 A Pop to Sis Final
3/39
a form of cell death designed to eliminate
unwanted host cells through activation of
coordinated, internally programmed series of
affected by a dedicated set of gene products.
Occurs under normal physiological condition
Can be induced by pathological conditions
-
8/8/2019 A Pop to Sis Final
4/39
Hypoxia
Defective Energy (ATP) Production
Physical Agents and Drugs
Free Radicals
Infectious Agents
Immunological ReactionsGenetic Derangements
Nutritional Imbalance
-
8/8/2019 A Pop to Sis Final
5/39
`Apoptosis (programmed cell death), isa normal component of the development
and health of multi-cellular organisms while
Necrosis (traumatic cell death) isuncontrolled cell death leads to lysis of
cells, inflammatory responses and,
potentially, to serious health problems.
-
8/8/2019 A Pop to Sis Final
6/39
Causes regression of anatomical structures in fetal
development
Eliminates self-recognizing lymphocyte clones inimmunologic processes
Prevents overpopulation in continuously renewing
tissues
Maintains the balance of cellularity in the responseof the tissues to hormones
Deletes mutant cells or those with DNA damage
Eliminates cells infected with viruses
-
8/8/2019 A Pop to Sis Final
7/39
-
8/8/2019 A Pop to Sis Final
8/39
-
8/8/2019 A Pop to Sis Final
9/39
APOPTOSIS Vs Death of single cells
Cytoplasmic blebbing
Chromatin condensation
Cell shrinkage Lysosomes and other
cytoplasmic organelles intact
Nuclear DNA breaks intofragments
Rapid phagocytosis of
apoptotic bodies bymacrophages and adjacentcells
No inflammatory response
NECROSIS Death of many cells
Plasma membranedisruption
Nuclear swelling and lysis Cell swelling
Lysosomal breakdown
Cell lysis and disintegration
Phagocytosis by
macrophage Often cause a damaging
inflammatory response insurrounding tissues
-
8/8/2019 A Pop to Sis Final
10/39
Defining features Apoptosis Necrosis
Physiologic/pathologic features
Cellular role Usually normal Abnormal, accidental
Process Active, energy-dependent
Passive, results from
lack/loss of energy
Distribution Dispersed, affectsindividual cells
Contiguous,
simultaneous, andmassive affects in
damaged tissue areas
Triggers 100s of physiologic
and noxious stimuli
Sudden transfer of
energy, specifictoxins, or ATP
depletion
Induction Slow (hours),stochastic
Rapid (secs, mins)
Tissue inflammation Absent Present
Cell removal Rapid and discrete Slow
-
8/8/2019 A Pop to Sis Final
11/39
Defining features Apoptosis Necrosis
Morphologic
featuresCellular membranes Integrity preserved,
blebbing of intactplasma membrane
Loss of integrity, with
spilling of cellconstituents
Cell volume Decreased, as well asthe formation of
small, fragmentedapoptotic bodies or
inclusions
Increased
Organelle structure Late preservation,with exception ofnuclear condensation
and fragmentation
Swelling of nucleus
and other organelles
Chromatin Discrete, organizedcondensation,
margination and
fragmentation (e.g.
pyknotic nuclei)
Pattern conserved
-
8/8/2019 A Pop to Sis Final
12/39
Defining features Apoptosis Necrosis
Biochemical and
molecular featuresMitochondrial permeabilitytransition
Moderate Severe
Mitochondrial membranepotential (delta psi-m)
Transient loss Permanent loss
Requirement fro ATP Yes No
Membrane phospholipidasymmetry
Exteriorization of
phosphatidylserine from
inner to outer leaflet of
plasma membrane
Unchanged
Cell pH Acidification Unchanged
DNA cleavage Initial specific large
cleavage products of 300,then 50, kbp, followed by
internucleosomal cleavage
leading to DNA ladder
pattern of 180 bp unit
repeats
Random DNA cleavage
Caspase dependence Yes No
-
8/8/2019 A Pop to Sis Final
13/39
-
8/8/2019 A Pop to Sis Final
14/39
The Extrinsic
or Death
ReceptorPathway
The Intrinsic or
Mitochondrial
Pathway
-
8/8/2019 A Pop to Sis Final
15/39
There are 4 key processes:
1. Induction
2. Activation3. Execution
4. Removal of dead cells
-
8/8/2019 A Pop to Sis Final
16/39
Triggered by transmembrane/external signals
or ligands:
Pro-apoptotic factors (Death signals) FasL TNF-
TRAIL
Anti-apoptotic factors Growth factors
Cytokines
Hormones
-
8/8/2019 A Pop to Sis Final
17/39
Components:
Death Ligands- FasL, TNF, TRAIL
Death receptors e.g. Fas (CD95),
TNF-R1, TRAIL-R1
Adapter protein e.g. Fas-
Associated Death Domain (FADD)Caspases
-
8/8/2019 A Pop to Sis Final
18/39
Cysteinyl-Aspartate Specific Proteases
Exist within the cell as inactive pro-forms or
zymogens
have been termed "executioner" proteins
Responsible for the cleavage of the key
cellular proteins that leads to morphologic
changes observed in cells undergoing
apoptosis
-
8/8/2019 A Pop to Sis Final
19/39
Initiator CaspasesCaspases -2, -8, -9
and -10
Activated inresponse to deathsignal
Possess long pro-domains (CARDdomain)
Activate effectorcaspases
Effector CaspasesCaspases -3, -6 and -7
H
ave short pro-domains
Executioner ofapoptosis
Their action leads
to morphologicalfeatures such asDNA fragmentation
-
8/8/2019 A Pop to Sis Final
20/39
-
8/8/2019 A Pop to Sis Final
21/39
-
8/8/2019 A Pop to Sis Final
22/39
1. Triggered by internal signals (pro-apoptotic)
such as: Growth factor deprivation
DNA damage Increased levels of reactive oxygen species
2. Regulated by Mitochodrial Outer Membrane
Permeabilization (MOMP)
3. Release of Cytochrome C
-
8/8/2019 A Pop to Sis Final
23/39
Activation or inactivation of an
inner mitochondrial permeability transition
pore, which is involved in the regulation of
matrix Ca2+
, pH, and voltage. Some Bcl-2 family proteins can induce (pro-
apoptotic members) or inhibit (anti-
apoptotic members) the release
of cytochrome c into the cytosol which, oncethere, activates caspase-9 and caspase-3,
leading to apoptosis.
-
8/8/2019 A Pop to Sis Final
24/39
-
8/8/2019 A Pop to Sis Final
25/39
-
8/8/2019 A Pop to Sis Final
26/39
-
8/8/2019 A Pop to Sis Final
27/39
-
8/8/2019 A Pop to Sis Final
28/39
-
8/8/2019 A Pop to Sis Final
29/39
-
8/8/2019 A Pop to Sis Final
30/39
-
8/8/2019 A Pop to Sis Final
31/39
` Differentiation of fingers and toes in a developing
human embryo occurs because cells between the
fingers apoptose; the result is that the digits are
separate.
` The effect of lack of programmed cell death (Specifically apoptosis) on
the toes of a human. A mutation caused the middle two toes to remainconnected.
-
8/8/2019 A Pop to Sis Final
32/39
` During menstruation
` Development of an organ or tissue is often
preceded by the extensive division anddifferentiation of a particular cell, the resultant
mass is then "pruned" into the correct form by
apoptosis
-
8/8/2019 A Pop to Sis Final
33/39
HIV Invades CD T Cells
CD T Cells dies
-
8/8/2019 A Pop to Sis Final
34/39
-
8/8/2019 A Pop to Sis Final
35/39
IMMUNEDEFENSE
Immune defense isthe coordinated,
complicated interplay
of cellular
mechanisms andantibodies to fight
disease-causing
agents, including
viruses, bacteria, andother types of
infection.
APOPTOSIS
Apoptosis plays a keyand essential role in
the education of
immune cells in the
thymus and the bonemarrow, where
autoreactive cells are
eliminated, thereby
establishing toleranceto self tissues.
-
8/8/2019 A Pop to Sis Final
36/39
The immune response to a foreign invader involves the proliferationof lymphocytes T and/or B cells. When their job is done, they
must be removed leaving only a small population of memory cells.
This is done by apoptosis.
Very rarely humans are encountered with genetic defects in
apoptosis.T
he most common one is a mutation in the gene for Fas,but mutations in the gene for FasL or even one of the caspases are
occasionally seen. In all cases, the genetic problem
produces autoimmune lymphoproliferative syndrome or ALPS.
Features: an accumulation of lymphocytes in the lymph nodes and
spleen greatly enlarging them.
The appearance of clones that are autoreactive; that is, attack
"self" components producing such autoimmune disorders.
the appearance of lymphoma a cancerous clone of lymphocytes.
-
8/8/2019 A Pop to Sis Final
37/39
Associated with dysregulated apoptosis
Apoptosis elimnates damage cells
Damage mutation Cancer
Many cancer cells are defective in apoptoticpressure
-
8/8/2019 A Pop to Sis Final
38/39
Histologic Examination
Tissues stained with H and E
Apoptotic cells
Fluorescent probes Mark apoptotic events in various ways
DNA strand breaks in situ
Change in mitochondria membrane potential
-
8/8/2019 A Pop to Sis Final
39/39
Annexin V assay
Binds with high affinity to phosphatidylserine on the
outer surface of membrane
Cellular DNA fragmentation ELISA Labeling of target DNA using BrdU
Monoclonal antibody
Cell-death inducing reagent
Dna fragments (necrotic cells) Lying agent
y DNA fragments (apoptotic cells)