Abstract 18046: Pim1 Kinase Overexpression Enhances ckit+ Cardiac Stem Cells Cardioreparative Ability After Intramyocardial Delivery in a Swine Model

Introduction: Pim-1 kinase plays an important role in cell division, survival and commitment of precursor cells towards a myocardial lineage. Hypothesis: We hypothesized that overexpression of Pim1 in ckit+ cardiac stem cell (CSCs) enhances their cardioreparative effect Methods: We treated immunosuppressed Yorkshire swine (n=29) with human ckit+ CSCs (n=10), Pim1 modified human ckit+ CSCs (n=9) or PBS (n=10) two weeks after MI. Cardiac MRI and PV loops were obtained before and after cell administration. Results: Whereas both pim1- and pim1+ c-kit cells reduced MI size, the Pim1 group had a ~3-fold decrease in scar mass at 8 weeks post transplantation compared to ckit+ (–29.2±2.7% vs. –8.4±0.7%, p<0.003). Pim1+ CSC injections also produced a 2-fold increase of viable mass compared to ckit+ CSCs at 8 weeks (113.7±7.2% vs 65.6±6.8%, p<0.003; Fig. 1B), a greater increase in regional contractility (Ecc) at infarct (–10±1.1 vs. –6.1±0.3, p<0.05, Fig. 1D) and border zones (–12.3±1 vs. –8.4±0.5, p<0.05; Fig. 1E)....