Diversity in the Mechanisms of Neuronal Cell Death

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Diversity in the Mechanisms of Neuronal Cell Death
Junying Yuan, Marta Lipinski, and Alexei
Degtrev Neuron , Vol. 40, P. 401- 413.

• 05. 28.
• Lab. Of Developmental Genetics
• Cheon, Seon hye

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- Contents -
Introduction
Apoptosis
Apoptosis in neuronal cell
Caspase-dependent apoptosis
AIF(apoptosis-inducing factor)
Autophagic cell death
Prodeath
Prosurvival
Self-clearance
Aurophagy in neurodegenerative disease
Necrosis
Fas induced signal
Intracellular Ca2 induced signal
Calpain-cathepsin hypothesis
Apoptosis or Necrosis
Summary
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Introduction
Neuronal cell death
Excess neurons removed
Die prematurely during adult life
3 Types of Neuronal Cell Death Highly conserved
during evaluation
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Neuronal Apoptosis - the Canonical Programmed
Cell Death

• Apoptosis highly orderly process displaying
  characteristic morphologic change
• - Nuclear condensation fragmentation, cytoplasmic
  shrinkage, plasma membrane
• blebbing, exposure of phosphatidylserine.
• - Apoptotic machinery is controlled by the
  balance of survival and death signals.
• Bcl-2, caspase, Apaf-1/ced-4 families constitute
  the core apoptotic machinery.
• - BH3-domain-only protein is a key event in the
  initiation of PCD.
• - caspase-dependent/-independent neuronal
  apoptosis

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NGF(Nerve Growth Factor) - regulated neuronal
survival pathway
Yuan and Yankner, 2000. Nature
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Caspase-dependent Neuronal Apoptosis - the
Canonical Programmed Cell Death
Egl-1
Ced-9 (BH3-only-domain) Turn on the cellular
death switch
Ced-4(pro-apoptotic adaptor) Ced3(caspase)
Apoptosis Cell death
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Caspase-dependent Neuronal Apoptosis - the
Canonical Programmed Cell Death
Bim, Dp5/Hrk (BH3-only-domain)

Bax/Bak (pro-apoptotic factor)
Increase permeability of mitochondria outer memb.
Efflux of cytochrom c
cytochrom c/Apaf-1/caspase-9 complex
Caspase 3 activation
ICAD
CAD
Formation of DNA ladder
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Caspase-dependent Neuronal Apoptosis - the
Canonical Programmed Cell Death
BH3-only protein
The expression of the proapoptotic gene Bax was
required in BH3-only protein-mediated death. Dp5
kills rat cerebellar granule neurons. Dp5-induced
apoptosis is Bax-dependent.
Harris and Johnson, 2001, J. Biol. Chem.
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Caspase-dependent Neuronal Apoptosis - the
Canonical Programmed Cell Death
Immunodetection of activated Casp3 in brain
stem. Caspase 3 - containing cells identified in
the wild-type tissue, but not in the mutant.
A multimolecular complex (cytochrome
C/Apaf1/Casp9)

Casp3 activation and apoptosis.
Wang, X. 2001. Genes Dev. Cecconi et
al.,1998.Cell.
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Caspase-dependent Neuronal Apoptosis - the
Canonical Programmed Cell Death
(A and C wild type, B and D Caspase 3-/-)
Reduced chromatin condensation and nuclear
pyknosis Extensive cytoplasmic vacuoles swelling
and dilation of mitochondria and rough
endoplasmic reticulum (RER)
Oppenheim et al., 2001. J.Neurosci.
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AIF(Apoptosis Inducing facotr) Double agent
of Life and Death
Downstream mediator of poly(ADP-ribose)
polymerase-1(PARP-1)-induced neuronal cell
death. A dual agent, which promotes DNA
fragmentation under apoptotic conditions and
maintains normal mitochondrial functions in
living cells.
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AIF(Apoptosis Inducing facotr) Double agent
of Life and Death
AIF is a downstream mediator of PARP-1
induced NMDA-induced excitatory neuronal cell
death. AIF is mediators of caspase-independent
neuronal cell death.
Cell count
PI fluorescence intensity
Nuclear translocation of AIF is PARP-1
dependent.
BAF and Z-VAD.fmk caspase inhibitor TMRM
indicator of mitochondria potential Annexin-V
apoptosis marker MNNG(N-methyl-N-nitro-N-nitroso
guanidine) DNA damaging agent
Yu et al., 2002. Science.
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AIF(Apoptosis Inducing facotr) Double agent
of Life and Death
AIF regulates granule cell hydrogen peroxide
sensitivity
1) Higher doses produced significant increases in
Hq mutant granule cell death 2) downregulation of
AIF confers sensitivity to both exogenous and
endogenous peroxides.
Transduction with wild-type AIF rescues the
peroxide sensitivity of Hq mutant neurons.
Klein et al., 2002. .Nature.
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AIF(Apoptosis Inducing facotr) - Double agent
of Life and Death
Massive apoptosis in the wild-type EBs No signs
of cell death among the inner cells of aif -/Y
EBs. Impaired cavitation in aif -/Y EBs is not
caused by enhanced proliferation but is due to a
failure of inner cells to undergo PCD.
AIF controls PCD during early morphogenesis
Arrow chromatin condensation
Joza et al., 2001. Nature.
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The role of autophgy in neuronal cell death

prodeath, prosurvival, or a self-clearance
mechnism?
The bulk degradation and recycling of damaged
or dysfunctional cytoplasmic components and
organelles. Cellular response to both extr-and
intra-cellular stress conditions.
Macro-autophagy Micro-autophagy
Chaperone-mediated autophagy
Klionsky and Emr, 2000. Science.
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The role of autophgy in neuronal cell death
prodeath
Neurons were plated with (A) or without NGF (BE)
for 16 h.
(A) Normal profiles of the nucleus (n),
mitochondria (m), and endoplasmic reticulum(er).
(B) Many autophagosomes were formed. (C)
Engulfed organelles in the autophagosomes.
Chromatin condensed. (D) Neurons exhibited DNA
condensation and fragmentation.
NGF-, serum-deprivation-induced sympathetic
neuronal cell death of PC12 cells exhibit
autophagic features.
Xue et al., 1999. Mol. Cell. Neurosci.
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The role of autophgy in neuronal cell death
genetic factor
Beclin 1 human ortholog of yeast Apg6/Vps30p
Bcl2-interacting protein
MCF7 beclin1
MCF7 beclin1
MCF7 control
Asterlike autophagic vacuole
Normal media
Serum and amino-acid deprivation
serum and amino-acid deprivation in the presence
of 3-MA
3-methyladenine (3-MA) inhibits the
autophagosome formation
Liang et al., 1999. Nature.
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The role of autophgy in neuronal cell death
prosurvival
The activation of autophagy in mammalian cells in
the event of nutrient and trophic
factor deprivation is a cellular strategy to
survive through perhaps temporary hardship
through recycling intracellular components.
Ohsumi., 2001. Nat. Rev. Mol. Cell Biol.
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The role of autophgy in neuronal cell death
self-clearance mechanism
Own body cremation through autophagy
Liang et al., 1999. Nature.
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The role of autophgy in neuronal cell death
apoptotic
process associated with the activation of
autophagy
Crowder and Freeman, 1998. J. Neurosci.
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The role of autophgy in neuronal cell death
Neurodegenerative diseases.
Yuan and Yankner, 2000. Nature
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Lysosome a suicide Bag?
Cellular pathways of amyloid-? protein
neurotoxicity in Alzheimers disease.
Yuan and Yankner, 2000. Nature
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Lysosome a suicide Bag?
?-hexosaminidase lysosomal enzyme
The induced lysosomal leakage in apoE3- and
apoE4-transfected cells.
apoE4 into lysosomal membrane facilitate the
nerotoxicity of A? by destabilizing lysosomal
membrane
Ji.et al., 2002. J. Biol. Chem.
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Regulated cellular Necrotic program
Fas and TNF family of death receptor Induce cell
death with necrotic features. (swelling of
mitochondria and ER, vacuolization, loss of the
mitochondrial transmembrane potential, dilation
of nuclear membrane)
Necrosis require both adaptor protein FADD and
Ser/Thr kinase RIP.
Loss of ATP synthesis is directly induced of
mitochondrial swelling.
Increase of cytoplasmic Ca2 initiate the
necrotic cell death.
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Regulated cellular Necrotic program
Fas-induced signaling
Fas-activated Jukat Cells
ZVAD Caspase inhibitor PDTC block
necrosis-induced mitochondrial membrane potential.
Matsumura et al., 2000. J. cell Biol.
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Regulated cellular Necrotic program
intrcelluar Ca2-induced signal
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Regulated cellular Necrotic program
Calpain-calthepsin hypothesis
Neurotoxic condirion Ischemic injury (NMDA
activation)
Ca2 overload
Calpain activation M-calpain ?-calpain
Neuronal cell death mediator necrotic cell death
Lysosomal cathepsin activation
Necrosis
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Apoptosis or Necrosis
Yamashima T.,2000, Prog. Neurobiol.
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Apoptosis or Necrosis
Increased Ca2 level or ER stress
Limited activation of m-calpain
Sufficient activation of calpain
Caspase-12 activation
Aspartyl protease activation
necrosis
apoptosis
E64d calpain inhibitor I and II
inhibition of cas12 cleavage
induced by OGD zVAD.fmk pancaspase inhibitor
no effect on the cleavage of
caspase12
Nakagawa et al., 2000. J. Cell Biol.