Generation of a Human Induced Pluripotent Stem Cell Line Expressing a Magnetic Resonance Imaging Reporter Gene

Abstract The objective of the current study is to develop a new method for tracking transplanted human induced pluripotent stem cells‐derived cardiomyocytes (hiPSC‐CMs) using magnetic resonance imaging (MRI). The CRISPR/dCas9 activation system is employed to overexpress ferritin heavy chain (FHC) in hiPSC‐CMs. The mRNA and protein expression of FHC in hiPSC and hiPSC‐CMs significantly increased after transfection. Iron chloride does not affect the cell viability in a concentration range from 0 to 2000 µ m . hiPSCs overexpressing FHC (hiPSC‐ FHC OE ) and hiPSC‐CMs overexpressing FHC (hiPSC‐CM‐FHC OE ) significantly enhanced cellular uptake of iron chloride but with no changes in electrophysiological properties compared to hiPSC‐CM‐Control. Furthermore, hiPSC‐CM‐FHC OE presented robust contrast and lower T 2 * values, signifying their potential as highly effective candidates for cardiac MRI. Next, hiPSC‐CM‐FHC OE is injected into mouse hearts and after 3 days of transplantation, MR images are obtained. hiPSC‐CM‐FHC OE cells exhibited clear signals in the hearts with lower T 2 * and rapid signal decay. Collectively, data from this proof‐of‐concept study demonstrated that endogenous labeling with FHC in hiPSC‐CMs can be a potent strategy for enhancing the accuracy of cardiac MRI. This technology represents a significant step forward in tracking the transplanted hiPSC‐CMs in the hearts of live animals.