Nuove Evidenze Sperimentali sui Potenziali Effetti Benefici dell

Capri
Cardiovascular Conference,
15-16 April, 2016, Capri
Nuove Evidenze Sperimentali sui
Potenziali Effetti Benefici
dell’Attivazione dell’Autofagia nelle
Malattie Cardiovascolari
Sebastiano Sciarretta, MD, PhD
Assistant Professor
Department of Medical-Surgical Sciences and Biotechnology,
"Sapienza" University of Rome, Latina, Italy
Heart Statistics-2015
Annual mortality due to cardiovascular diseases and cancer
Mozaffarian et al. Circulation 2015
What is Autophagy?
Galluzzi et al. EMBO J 2015
Cellular Stress and Autophagy
King. Trends Molec Med 2012
Sciarretta, Clin Science 2015
Autophagy Is Required for the Cardiac Adaptation
to Pressure Overload
Nakai et al. Nat Med 2007
Autophagy Promotes Survival during CM Energy Deprivation
Adapted from Matsui et al. Circ Res 2007 and Takagi et al. Autophagy 2007
Is a Dysregulation of
Autophagy Potentially
Involved in the
Development of Human
Cardiovascular Diseases?
High Fat Diet-Induced Obesity Inhibits
Autophagy in the Heart
Control Diet High Fat Diet
Myocardial
Ischemia
Obesity
MS
Ischemia
Autophagy
Ischemia+
Chloroquine
P<0.05
Control
Diet
High Fat
Diet
Dots/Field (n)
48
36
P<0.05
24
12
0
CD
HFD
CD
HFD
Chloroquine
Inhibition of mTORC1 Is Protective through
Restoration of Autophagy
P<0.05
P<0.05
75
MI Size/AAR (%)
Obesity
MS
50
#
Autophagy
25
Cardioprotection
0
CD
HFD
Vehicle
CD
HFD
beclin-1+/- beclin-1+/HFD
HFD+
Rapamycin
Rapamycin
Sciarretta et al. Circulation 2012
High Glucose Inhibits Autophagy in Endothelial Cells
Bafilomycin
HG
HG
CT
6h
24h
CT
6h
24h
LC3
High
Glucose
GAPDH
Bafilomycin
CT 6d
LC3
HG 6d
CT 6d
HG 6d
Endothelial
Autophagy
GAPDH
Sciarretta – Frati. Preliminary results
High Glucose Inhibits Stress-Induced Autophagy
Normal Glucose
High Glucose
STRESS
Cells with autolysosomes (%)
Hypoxia (6 hours)
High
Glucose
80
*
60
40
20
0
Normal
Glucose
High
Glucose
Endothelial
Autophagy
Autophagy Reactivation Rescues Angiogenesis
High
Glucose
Endothelial
Autophagy
Angiogenesis
TUNEL-postivie cells (%)
Autophagy Reactivation Rescues Cell Survival
25
STRESS
20
15
High
Glucose
10
Endothelial
Autophagy
5
0
LACZ
ATG7
LACZ
ATG7
Survival
HG
ATG7
TUNEL
DAPI
LACZ
High Glucose
ATG7
LACZ
Hypoxia (24 hours)
Sciarretta – Frati. Preliminary results
Autophagy Defect Is Associated With Increased
Stroke Susceptibility
LC3
ACTINA
SR
SR+
JD
SP
SP+
JD
Stroke
Susceptibility
Autophagy
Sciarretta– Rubattu. Preliminary results
Cardiac Autophagy Is Inhibited in Heart Failure
Heart Failure
Autophagy
Maejima et al. Nature Medicine 2013
Pharmacological Activators of Autophagy
mTOR
Inhibitors
Rapamycin
AMPK
Activators
AICAR
SIRT1
Activators
Resveratrol
P300
Inhibitors
Spermidine
Autophagy
Trehalose
Trehalose Is an Autophagy Inducer
Trehalose
Trehalose is a natural alpha-linked
disaccharide which is synthesized by
bacteria, fungi, plants, and invertebrate
animals
Dehydration
In lower organisms intracellular levels of
trehalose increase during dehydration and
stress, thereby promoting cell survival
Autophagy
Oxidative
Stress
Trehalose
Survival
Trehalose
Protein
Aggregates
Cellular
Stress
Energy
Stress
In mammalian systems, trehalose
administration promotes
autophagy through which it
reduces protein aggregates,
oxidative and energy stress
Hypothesis
Trehalose
Chronic
MI
Autophagy
Protein
Aggregates
Mitochondrial
Dysfunction
Energy
Stress
Cardiac
Remodeling
Heart Failure
Sciarretta – Volpe – Sadoshima. Preliminary results
Trehalose Administration Promotes Cardiac
Autophagy In Vivo
GFP-LC3 Dots
(fold vs. control)
9
Control
P<0.05
Trehalose
P<0.05
Control
6
3
Chloroq
0
CT
Tre
CT
Tre
Choloroquine
50 μM
Trehalose
Cardiac
Autophagy
Sciarretta – Volpe – Sadoshima. Preliminary results
15
P<0.05
10
5
0
CT
Tre
Wild Type
Fractional Shortening
(%)
NS
45
CT
Tre
beclin-1+/-
P<0.05
LV end-diastolic diameter
(mm)
Lung Weight//Tibia Length
(mg/mm)
Trehalose Reduces Heart Failure and Improves
Cardiac Function during Chronic MI
NS
P<0.05
4.5
3.0
1.5
0.0
CT
CT
Tre
Wild Type
Tre
beclin-1+/-
NS
Trehalose
30
Autophagy
15
0
CT
Tre
Wild Type
CT
Tre
beclin-1+/-
Heart Failure
Systolic Dysfunction
TUNEL-positive nuclei (%)
Trehalose Reduces Apoptosis after MI
P<0.05
NS
0.006
Trehalose
0.004
Autophagy
0.002
Apoptosis
0
CT
Tre
Wild Type
CT
Tre
beclin-1+/-
Conclusions
• Autophagy is required for the cardiac
adaptation to stress, thereby limiting myocardial
damage
• Inhibition of autophagy contributes to the
detrimental cardiac and vascular effects of
obesity and diabetes
• Inhibition of autophagy is associated with
stroke susceptibility and heart failure
• Trehalose represents a potentially useful drug
to activate autophagy during myocardial
ischemia
Acknowledgements
Rutgers New Jersey Medical School,
Newark, NJ, USA
Jun Sadoshima
Derek Yee
Peiyong Zhai
Dan Shao
Yasuhiro Maejima
Narayani Nagarajan
Daniela Zablocki
Chris Brady
University of Milan
Gianluigi Condorelli
UCSD-La Jolla, San Diego, CA
Kun-Liang Guan
University of Rome “Sapienza”, Italy
Giacomo Frati
Antonella Bordin
Silvia Palmerio
Leonardo Schirone
Elena De Falco
IRCCS Neuromed, Italy
Massimo Volpe
Speranza Rubattu
Carmine Vecchione
Simona Marchitti
Sara Di Castro
UT Southwestern, Dallas, TX, USA
Lance Terada
Funding