BL signal intensity of FLuc-iPSC and FLuc-iPS-CM depends on the cell dose, genomic locus of transgene integration and site of transplantation.
A. Optical signal intensity of serial dilutions of 2.5×104 undifferentiated iPSC and purified iPS-CM expressing FLuc from random loci or ROSA26 locus were measured in IVIS. Images are representative results of one serial dilution in triplicate for each cell type. B. Demonstration of linearity between cell dose and BL intensity (BLI) of cells shown in panel A. The data are given as mean ± SD of BLI for each cell dose in photons/second/cm2/steridian. R2 values: FLuc-ROSA-iPSC: 0.9942; FLuc-ROSA-iPS-CM: 0.9876; FLuc-iPSC: 0.9962; FLuc-iPS-CM: 0.9913. C,D. Linear relationship between BL signal intensity and cell dose after transplantation of indicated numbers of pUbC-FLuc-ROSA-iPSC and their purified CM into the mouse hind limb muscle. Representative BL images of transplanted mice are shown in panel C and quantitative analysis of these data is shown in panel D as mean ± SD (n = 4) of BLI. E. Representative BL images of mice that received intramyocardial injections of 5×105 pUbC-FLuc-iPS-CM or pUbC-FLuc-ROSA-iPS-CM. BL imaging was performed 6 hours after cell injection. F. Quantitative analysis of BLI in this experiment is given as mean ± SD for the indicated number of mice. Statistical analysis: two-tailed paired Student's t-test.
