Cellular Responses to Oxygen Deprivation and Recovery

1. Cellular Responses to Oxygen Deprivation and Recovery Emily Archer Slone Division of Biology Forum 3 March 2012 http://hyperbaricworx.com.au/how-hbot-helps/

2. Ischemia / Reperfusion Examples: Heart attack and stroke Hemorrhage Transplanted organs and surgery The Internet Journal of Surgery. 2008 Volume 16 Number 1 Ischemia is a lack of oxygen and nutrients to tissue Reperfusion is a return of blood flow to the tissueswhich results in greater injury than ischemia alone

3. Rag-1-/- + 2 specific Ab Wildtype C57Bl/6 Rag-1-/- No antibodies Have antibodies Given 2 antibodies IR IR Sham IR No damage Damage No damage Damage Fleming, S. D. et al. 2004. J. Immunol. 173:7055-7061. Williams, J. P., et al. 1999. J. Appl. Physiol. 86:938-942. Fleming, S. D. et al. 2004. J. Immunol. 173:7055-7061.

4. In vitro Model Hypothesis: Endothelial cells are the major cell type responsible for the increased prostaglandinproduction in wildtype mice following IR

5. LysoPC PC AA PLA2 + COX LOX Leukotrienes Prostaglandins (PGE2)

6. Methods Mass Spectrometry Analysis Prostaglandin E2 Concentration mRNA Expression Hypoxia Chamber Lipid Extraction

7. Endothelial cells produce prostaglandin E2 uponre-oxygenation

8. Lipid changes occur during hypoxia

9. Flippase P type ATPase Floppase Abc transporters Scramblase extracellular intracellular ATP ADP ATP ADP Ca2+ What is driving the lipid changes?

10. Phospholipidscramblase 1 transcript increases upon re-oxygenation θ θ

11. Conclusions • Endothelial cells respond to hypoxia/re-oxygenation similar to IR-treated tissue • Lipid changes begin during hypoxia • Downstream effects, namely PGE2 production, occur following re-oxygenation • Phospholipidscramblase 1 may be contributing to membrane lipid changes

12. Acknowledgements Dr. Sherry Fleming Kaori Knights Mike Pope Andrew Fritze Division of Biology NIH NSF GK-12 Terry C. Johnson Center for Cancer Research Kansas Technology Enterprise Corportation BRITE Dr. Ruth Welti Mary Roth