Aging and selective degradation of cytosolic proteins in lysosomes

1
Reactivating Chaperone-mediated Autophagy the
advantages of preserving a selective autophagy
Ana Maria Cuervo MD PhD Department of Anatomy and
Structural Biology Marion Bessin Liver Research
Center Albert Einstein College of Medicine,
Bronx, NY
2
Protein damage/repair
Young
Insult
Aggregates
3
Chaperone-mediated Autophagy and Aging

• Overview of CMA
• CMA and Aging
• Changes
• Consequences
• Causes
• Restorative efforts

4
Types of Autophagy in Mammals
ENDOCYTOSIS
MICROAUTOPHAGY
CHAPERONE- MEDIATED AUTOPHAGY
Golgi
endoplasmic reticulum
MACROAUTOPHAGY
5
Chaperone-Mediated Autophagy (CMA)
substrate proteins KFERQ-motif
lysosome
6
Types of Autophagy

Chaperone-mediated
Macroautophagy
Microautophagy
7
Characteristics of Chaperone-Mediated Autophagy

• Described Fibroblasts in culture, other cells
  type
• Animal tissues (liver, kidney,
  spleen)

• Regulation Nutrient deprivation
• (Stress) Toxic exposure
• Oxidative stress

• Substrates Selective cytosolic proteins (30)
• Target signal KFERQ-like

• Malfunctioning Toxic-induced nephropathy
• Galactosialidosis
• Aging
• Parkinsons Disease

8
Chaperone-mediated Autophagy and Aging

• Overview of CMA
• CMA and Aging
• Changes
• Consequences
• Causes
• Restorative efforts

9
CMA in old Fibroblasts
10
Degradation of CMA Substrates by Lysosomes
Cuervo Dice (2000) J. Biol. Chem.
11
Chaperone-mediated Autophagy and Aging

• Overview of CMA
• CMA and Aging
• Changes
• Consequences
• Causes
• Restorative efforts

12
Protein Degradation and Aging

• Intracellular Protein Content Increases with Age
• Accumulation of Damaged Proteins is a Common
  Feature of Old Tissues

13
Proteolytic systems inside the cell
Cytosol
Proteasome
Nuclei
Lysosome
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Oxidized proteins in lysosomes
Roberta Kiffin
Cytosol
- - -
Kiffin et al. (2004) Mol. Biol. Cell
15
CMA During Mild Oxidative Stress
16
CMA and Oxidative Stress
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Consequences of declined CMA with age
Impaired elimination of oxidized proteins
18
Consequences of CMA blockage
Ashish Massey
19
Effect of CMA Blockage
Are cells OK with this switch?
20
Consequences of CMA blockage
Deregulation of the response to stress
MTT- Viability assay
140
120
wt
100
80
Viable cells ()
60
40
20
0
42 C
H202 (50 mM)
Paraquat (1 mM)
Cadmium (10 mM)
UV
24 hours post-insult
Massey et al. (submitted)
21
Consequences of declined CMA with age
Impaired elimination of oxidized proteins
Deregulation of the response to stress
22
Chaperone-mediated Autophagy and Aging

• Overview of CMA
• CMA and Aging
• Changes
• Consequences
• Causes
• Restorative efforts

23
CMA and Aging Step by Step
chaperones
substrate
lamp2a
lysosome
Cuervo and Dice (2000) J. Biol. Chem.
24
Regulation of CMA
Degradation
OK
Redistribution
25
Proteomics of the Lysosomal Membrane
Lysosomes
Lys. membrane
Guy Sovak
Rat liver lysosomal membranes
26
Chaperone-mediated Autophagy and Aging

• Overview of CMA
• CMA and Aging
• Changes
• Consequences
• Causes
• Restorative efforts

27
Caloric Restriction and CMA
Anna Kim
28
The CMA-Regulated Animal Model
Judy Zhang
29
The CMA-Regulated Animal Model
Cong Zhang
30
Late restoration
-Dox
100
75
50
Levels lamp2a
25
20
15
10
5
0
Months
31
There is hope for CMA
is that all?
32
Autophagy and Aging

Chaperone-mediated
Macroautophagy
Microautophagy
33
Autophagy Crosstalking
Susmita Kaushik
Lysosome
MACROAUTOPHAGY
34
Proteolytic cross-talking
TISSUE
TIME
CMA
MICROAUTOPHAGY
Lysosome
MACROAUTOPHAGY
35
The Faces of CMA
Ashish Massey
Judy Zhang
Guy Sovak
Roberta Kiffin
Oxidative Stress
Blockage of CMA
Lysosome Proteome and Aging
Lamp2a Transgenic Mouse
Anna Kim
CR
Urmi Bandyopadhyay
Marta Martinez
CMA and Neurodegeneration
Susmita Kaushik
Identification New components
lysosome
Cross-talking
36
Acknowledgements
COLLABORATORS

• J. Fred Dice (Tufts University, MA)
• David Sulzer, Serge Przedborski (Columbia U., NY)
• Peter Lansbury (Harvard University, MA)
• Harry Ischiropoulos (U. Penn, PA)
• Ralph Nixon (New York University, NY)
• Noburu Mizushima (Tokyo MI, Japan)

CMA
CMA and PD
Autophagy and AD
Cross-talking