BLI of hMSC localization in VD rats: a Representative longitudinal BLI images from a VD rat showing increasing BLI signal on days 1 and 2 following periurethral injection of luciferase-expressing hMSCs. b Mean BLI signal in VD animals significantly increased on days 1 and 2 (P < 0.05) in comparison with day 0, suggestive of hMSC recruitment/viability. No significant difference was observed for non-VD rats. c Representative urethra 2 h after hMSC injection demonstrates hMSCs: human-specific Alu repeats clearly revealed nuclear staining of hMSCs, whereas no positive Alu signal was found in urethra of imaged animals when BLI signal disappeared. Light microscopy ×40. BLI bioluminescence imaging, hMSC human mesenchymal stem cells, VD vaginal distention. Reprinted with permissions from Sadeghi et al.