1. The Cardiac Atrial appendage Stem Cell: a true candidate for myocardial repair? 7th International Symposium On Stem Cell Therapy and Cardiovascular Innovation May 7th, 2010 in Madrid Severina Windmolders PhD Student, Hasselt University, Belgium Laboratory of Experimental Haematology, Jessa Hospital, Hasselt, Belgium

2. 2 Introduction Myocardial infarction = irreversible loss of cardiomyocytes Occluded artery Scar formation

3. 3 Introduction Therapies Changes in life style (stop smoking, lose weight,…) Pharmacological (β-blockers, diuretics,…) Surgical (CABG, implantation of VAD, …) Improving patients life quality BUT Do not replace scar tissue

4. 4 What: Local replacement of scar tissue Restoring heart function Introduction Ideal therapy Stem cell therapy?

5. Introduction Cardiac stem cells 1

6. 2 Cardiac Atrial Appendage Stem cells A. Isolation Heart auricle Tissue dissociation Collagenase type II Single cell suspension Aldefluor® Reagens CASCs

7. 3 Cardiac Atrial Appendage Stem cells A. Isolation Aldefluor + DEABAldefluorAldefluor + CD34 Ab + CD45 Ab 0,9±0,8%0%83,8±13,4%

8. 4 Cardiac Atrial appendage Stem Cells B. Clonogenicity 15,5% clonogenicity

9. 5 Cardiac Atrial appendage Stem Cells C. Expression of pluripotency-associated genes Oct-4 Nanog C-myc Klf-4 1000bp 200bp 1500bp 600bp 1000bp 200bp 1000bp 200bp 1 1 Lin-28 DPPA-3 Tbx-3 C-kit 1000bp 200bp 1000bp 200bp 1000bp 200bp 1000bp 200bp 1. Freshly isolated 2. Ex vivo expanded - Negative control (H2O) 1 2 2 - -

10. 2 CASCs are not mobilised from peripheral blood or bone marrow A.Antigenic expression profile

11. 7 CASCs are not mobilised from peripheral blood or bone marrow B. Functional comparison Adipogenic differentiation Osteogenic differentiation Haematopoietic differentiation ALDH+ ALDH+ bone marrow heart tissue

12. A. Expression of cardiospecific genes 8 CASCs differentiate into cardiomyocytes b-actin TnT a-actinin MHC Cx43 Kv4.3 a1c GATA-4 1. Freshly isolated 3. Co-cultured with neonatal rat cardiomyocytes 2. Ex vivo expanded CM = human cardiomyocytes (+)

13. B. Expression of cardiospecific proteins 9 CASCs differentiate into cardiomyocytes

14. Cardiac Atrial appendage Stem Cells Resident stem cells in the human heart Not mobilised from peripheral blood or bone marrow Elevated activity of ALDH enzyme Cardiomyogenic differentiation after co-culture with neonatal rat cardiomyocytes 10 Conclusion

15. Acknowledgements Jessa Hospital Campus Virga Jesse K. Hensen, PhD 1 R. Koninckx, PhD 1,2 A. Daniëls, MSc 1 M. Hendrikx, MD 2,3 J.-L. Rummens, MD 1,2 1.Laboratory of Experimental Haematology, Jessa Hospital 2.Laboratory of Physiology, Hasselt University 3.Department of Cardiothoracic Surgery, Jessa Hospital 11