Recombinant human annexin A5 therapy improved cardiac function and survival rates in mice with endotoxemia (bacterial infection). Annexin A5 inhibits the binding of lipopolysaccharide from gram-negative bacteria to Toll-like receptor 4, decreasing inflammatory cytokine production and cardiac dysfunction. Treatment with annexin A5 significantly reduced myocardial tumor necrosis factor-alpha and interleukin-1 beta expression and restored normal cardiac function by inhibiting nuclear factor-kappa B activation. This led to improved short-term survival rates in mice with endotoxemia.

1. Recombinant Human Annexin A5 Therapy –
Inhibition of Proinflammatory Response with
Improved Cardiac Function and Survival Rate
in Mice with Endotoxemia
Ashley Davis
University of North Florida

2. Collaborative Research
• Paul Arnold & Fatemeh Armirahmadi – Department of
Physiology and Pharmacology at the University of Western
Ontario, London, Canada
• Xiangru Lu MD - Center of Critical Illness Research at the
Lawson Health Research Institute ON, Canada
• Katharina Brandl PhD – Department of Genetics at the The
Scripps Research Institute La Jolla, California
• Qingpin Feng MD, PhD – Department of Medicine at the
University of Western Ontario, London, Canada
• Dr. Feng is a career investigator at Heart and Stroke Foundation
of Canada

3. Endotoxemia
✧ Bacteria enter bloodstream and release endotoxins
✧ WBCs react to the presence of bacteria and release inflammatory substances
– excessive cytokine production
✧ 18 million cases annually
✧ Increased endothelial permeability
• Stage (II) - Severe Sepsis
• Organ dysfunction
• Mortality rate: 30-40%
• Stage (III) - Septic shock
• Myocardial depression
• Mortality rate: 40-80%
NIAID/RML, Science 2002

4. Host’s Immunity
✧ Host’s innate immunity activated
✧ TLR2 = Gram-positive
✧ TLR4 = Gram-negative
✧ Activation of TLR4 via LPS binding
✧ Initiates signaling pathway that leads to
✧ activation of MAPKs (mitogen-activated protein kinases)
✧ production of inflammatory cytokines - tumor necrosis
factor (TNF-α) and Interleukin (IL-β)
Celeste Thorpe MD 2004

5. Roll of Toll-like Receptors
Modlin, Nature 2000

6. LPS
• Lipopolysaccharide
• From Gram-negative bacteria
• LPS binds to TLR4 in CD14
• Binding of LPS activations signaling
pathway that leads to activation of MAPKs
and production of inflammatory cytokines
• Necrosis factor alpha (TNF-α)
• Leading cause of cardiac dysfunction
• Interleukin-1 beta (IL-β)
Feng et al. Crit Care Med, 2014

7. Previous Treatment
• Xigris = Activated Protein C
• Indications: for severe sepsis & septic shock
• Acute organ failure
• Properties: Anticoagulant, Anti-inflammatory, Profibrinolytic
• Side Effect: Serious Bleeding
• Was the only approved therapy by the U.S Food and Drug
Administration
• No longer used due to severe bleeding risk
• Results from trial showed no survival benefit over placebo
• Xigris was voluntarily withdrawn from market in 2011
FDA Medwatch, 2011

8. Annexin A5
• A 35-kDa phospholipid binding protein
• High affinity binding to negatively charged phospholipids
• Has antiapoptotic and anticoagulant properties – by forming 2D
crystallized shield over the surface of cells
• Shield decreases ability to initiate phagocytosis or thrombosis
• Anx5 interacts with cell receptors to inhibit their function in binding to
leucine-rich repeats
• LPS binds to extracellular domain of TLR4 at leucine-rich repeats
• Anx5 inhibits LPS binding to TLR4 and thus decreases
downstream MAPK signaling
HTI Inc, 2009

9. Results
• Anx5 improved cardiac function and survival rate during
endotoxemia by inhibiting LPS binding to TLR4/myeloid
differentiation factor 2 (MD-2) receptor complex
• Anx5 decreased myocardial TNF-α and IL-βexpression
• Anx5 restored cardiac function to control levels
• via the inhibition of activation of NF-kB
Feng et al. Crit Care Med, 2014

10. Anx5 decreases myocardial MAPKs and
NK-κB
Feng et al. Crit Care Med, 2014
Cardiac
Tissue
MAPK
Side Pathway

11. Treatment with Anx5 significantly
decreased myocardial TNF-αand IL-1β
Feng et al. Crit Care Med, 2014
mRNA
Protein
Plasma

12. Anx5 Improves Cardiac Function
Feng et al. Crit Care Med, 2014
Measuring mean
arterial pressure

13. Improved Survival Rates
5 day animal survival was significantly improved by either the immediate or 4-hour delayed
Anx5 treatment following LPS challenge.
Feng et al. Crit Care Med, 2014

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