Fig. 1.

AkaLuc and FLuc transduced cells retain characteristics of untransduced UC-MSCs. a Schematic of the lentiviral vector used to generate MSCs expressing the reporters. The same vector backbone was used, and only the gene encoding for the luciferase was modified for expression of either FLuc or AkaLuc. Image produced using SnapGene software (from Insightful Science;

available at snapgene.com). b Representative phase contrast and fluorescence images of untransduced, AkaLuc and FLuc expressing MSCs when fully confluent. ZsGreen expression can be observed in the green channel for the transduced cells. Scale bar = 200 μm. c Levels of transgene expression in AkaLuc⁺ and FLuc⁺ MSCs at different passages. ZsGreen expression was measured via flow cytometry at p7 and p12 and untransduced MSCs were used as a negative control. The levels of ZsGreen are equivalent for both populations at p7 and remain largely unchanged up to p12, with a slight reduction for AkaLuc cells. The mean fluorescence intensity (MFI) of FLuc population shifted from 1023 at p7 to 708 at p12, while the MFI of AkaLuc population shifted from 746 at p7 to 388 at p12 (arbitrary units). d Cumulative doubling measured from passages 7 to 12 shows that cells proliferate at the same rate up to p11. e Flow cytometry analysis of markers that identify MSCs shows that all populations are positive for CD44, CD73, CD90 and CD103, and negative for CD45. f Fluorescence images of cells stained with phalloidin (f-actin, red) and DAPI (nuclei, blue), acquired at × 100 (left panel) and × 200 (right panel) magnification. Scale bar = 200 μm. g Area, perimeter, and circularity, as measured based on the phalloidin staining of at least 50 cells per replicate, show that MSCs retain their morphology after transduction with either of the reporters. Data are displayed as mean ± SD from n = 3. One-way ANOVA revealed no statistically significant difference between the three cell populations