Abstract 19831: In Vivo Molecular Imaging of Human Pluripotent Stem Cell-derived Cardiomyocytes in a Murine Myocardial Injury Model via a Safe Harbor Integration of a Reporter Gene
Background: Clinical application of pluripotent stem cells and their tissue specific derivatives will require in vivo monitoring of engraftment and systemic distribution following transplantation. Clinical translation of molecular imaging, employing reporter gene (RG) technology, requires site-specific transgene insertion at safe harbor loci, such as AAVS1.
Hypothesis: Zinc finger nuclease (ZFN)-mediated integration of a RG into the AAVS1 locus in human embryonic and induced pluripotent stem cells (hESCs and iPSCs) will allow monitoring of pluripotent stem cell-derived cardiomyocytes (hCMs and iCMs) in host myocardium.
Methods and Results: ZFN technology was used to integrate a triple fusion RG, containing firefly luciferase (BLI), red fluorescent protein (RFP) and herpes simplex virus thymidine kinase (PET), under regulation of a constitutive ubiquitin promoter, into the AAVS1 locus of hESCs and iPSCs. hESCs and iPSCs monoclonal lines were then differentiated into hCMs and iCMs, respectively, under chemically defined conditions using CHIR and IWR small molecules to modulate Wnt pathway activity. Co-localization of cardiac phenotype and striated morphology was readily observed (Fig. A). Site-specific integration was confirmed by southern blot analysis. RG expression by BLI was maintained successfully over 3 months in vitro. The hCMs (n=6) and iCMs (n=1) were transplanted into murine myocardial injury model. Four weeks post-injury, LVEF was better preserved in all cell-treated vs. PBS-treated mice (26.50 ± 2.325 (N=6) vs. 15.40 ± 4.600 (N=3), p<0.05). Robust in vivo expression of ZFN-edited BLI and PET signal of engraftment persisted for 4-weeks duration (Figs. B and C).
Conclusion: This study demonstrates the successful use of ZFN-edited cells to confirm the engraftment of hCMs and iCMs. ZFN technology enables targeted site-specific insertion of RGs to allow clinical translation of molecular imaging in cell therapy.
Author Disclosures: E. Rulifson: None. Y. Matsuura: None. M. Ariyama: None. M. Wang: None. R. Thakker: None. A. Tachibana: None. J. Wu: None. P. Yang: None.
- © 2014 by American Heart Association, Inc.