Abstract 18777: A Novel MicroRNA Cocktail for Improving Survival of Transplanted Cardiac Progenitor Cells
Introduction: Ischemic heart disease is the leading cause of death in the United States. Cardiac progenitor cells (CPCs) have shown great promise for cardiac regenerative medicine. MicroRNA (miRNAs) are small non-coding RNAs which negatively regulate gene expression. We hypothesize that screening for a pro-survival/anti-apoptotic miRNAs cocktail can improve the survival of CPCs and enhance cell therapy after myocardial infarction (MI).
Methods: Sca-1+ CPCs were isolated from transgenic mice (constitutively expressing luciferase and eGFP) with anti-Sca-1 microbeads. CPCs were transduced with individual lentiviral vectors carrying precursor of miR-21, miR-24, miR-221, a cocktail of all 3 miRNAs, or GFP as control. For in vitro testing, CellTiter-Fluor Cell Viability Assay was used after challenge with serum free medium. For in vivo testing, we injected the transfected cells intramuscularly. For targets bioinformatics prediction, we employed miRanda and TargetScan algorithms to evaluate the potential targets of these miRNAs.
Results: FACS indicated that isolated CPCs are Sca-1+ and CD45− cells. CPCs transduced with individual lentivirus showed higher cellular viability. More importantly, CPCs with miRNAs cocktail transduction showed highest cellular viability. Following intramuscular injection, CPCs expressing miRNAs showed significantly more robust bioluminescence signals compared to control CPCs at day 5 (18,734±1241 vs. 12,783±912 p/s/cm2/sr; P<0.05). Bioinformatics assay indicated many apoptotic genes were targets of these 3 miRNAs, including Casp3, Casp8ap2, Bax, Pdcd4, and Fasl. Similarly, Foxo3, Bcl2l11 and Ak2 are apoptotic activators or effectors that were predicted to be potential suppression targets by all the three miRNAs.
Conclusion: miRNAs cocktail can improve CPC survival both in vitro and in vivo. miRNAs preconditioned CPCs may represent a potential strategy to improve cell survival after transplantation.
- © 2010 by American Heart Association, Inc.