1. A Novel Large Animal Model of ARDS induced by Mitochondrial Products
Pablo Sanchez, MD PhD
AATS 2015
Seattle

2. No Disclosures

3. Acute Respiratory Distress Syndrome
-Morbidity and Mortality modest decline
-Treatment remains primarily supportive
-Pharmacologic therapies not effectively translated
-Need for animal models to test new hypotheses

4. ARDS: Pathogenesis -Dysregulated Inflammation
*Activation Innate Immune System
Pathogens PAMPs
Cell injury molecules DAMPs
*Uncontrolled Activation of Coagulation
-Alveolar Barrier Disruption
* Altered alveolar and endothelial permeability

5. Eukaryotic Cell Sepsis Cell Injury Neutrophil Activation Bacteria
Evolution
Mitochondria
Sepsis
Cell
Injury
Molecular
Products
PAMPs
Molecular
Products
DAMPs
TLR
Neutrophil
Activation

6. Rat lung: sham Rat lung : MTD
NATURE March 2010
Mice lung: sham Mice lung : Histones
Am J Respir Crit Care Med Jan 2013

7. Hypothesis
Injection of Mitochondrial Products in swine activates the innate immune system resulting in SIRS and ARDS.
This response is clinically similar to models of “infectious sepsis”.

8. Methods Isolated Mitochondria Disrupted by sonication 35-45 Kg Male
Yorkshire
35-45 Kg Male
Yorkshire

9. Methods Control Group n=3 LPS Group n=3 50ng/kg
mt-DAMPs n= µg/ ml of blood volume
Animals received supportive treatment according to Surviving Sepsis Guidelines

10. Results: Clinical Signs of SIRS* * * NS
WBC (cells/mcL)
*p<0.05
mt-DAMPs and LPS developed clinical signs of SIRS
mt-DAMPs led to leukocytosis
LPS led to leukopenia

11. Results: Clinical Signs of ARDS* * * NS NS
Final PaO2/FiO2
Oxygenation Index
Wet/Dry ratio
*p<0.05
mt-DAMPs and LPS showed decreased P/F ratios
mt-DAMPs and LPS showed increased Oxygenation Index

12. Results: Histology quantification of ARDS*
H & E Myeloperoxidase NS
Control
LPS
DAMPs
Lung Injury Score * *
MMP-8 protein expression
*p<0.05

13. Results: Lung and Systemic Inflammation* * NS NS
LPS
DAMPS
mRNA fold increase from Controls
Lung IL-6 pg/mg protein
Serum IL-6 (pg/ml)
IL-6
TNF-α
Procalcitonin
BL HR6
BL HR6
BL HR6
Control
LPS
DAMPs
*p<0.05
No differences chemokine levels between mt-DAMPs and LPS

14. Conclusions
Our data demonstrates that the release of mitochondrial products to the circulation leads to SIRS and ARDS.
In its acute phase, this response is indistinguishable from LPS induced sepsis.
There were subtle differences between the models which require further investigation.

15. Thank you! Division of Cardiac Surgery University of Maryland SOM
Bartley Griffith
James Gammie
Si Pham
Keshava Rajagopal
Chetan Pasrija
Matthew Mulligan
Diana Pratt
Division of Cardiac Surgery
University of Maryland SOM
Artificial Organs Laboratory
Mandheer Wadhwa
Tieluo Li
Thank you!