Abstract
1431
Objectives: The conventional method for the analysis of stem cell transplantation depends on postmortem histology. Here, we have sought to demonstrate the feasibility of a longitudinal monitoring of transplanted cell survival in living animals, by employing optical imaging techniques. Methods: Mouse embryonic stem cells (ESC) were obtained from American Type Culture Collection (ES-E14TG2a). Mouse ES cells were cultured in the DMEM (Gibco-BRL, Gaithersburg, MD) supplemented with 3.7 g/L sodium bicarbonate, 1% penicillin and streptomycin, 1.7 mM L-glutamine, 0.1mM β-mercaptoethanol, 5 ng/mL mouse leukemia inhibitory factor (LIF), and 15% fetal bovine serum (FBS) with or without a feeder layer and cultured for five days in standard medium plus LIF. ESCs were then transfected (MOI=100) overnight with Ad-CMV-Fluc. Our experimental Sprague-Dawley rats (n=7) were given with different numbers of ESCs (105, 106, 5x106) expressing Fluc into corpus cavernosum. Sham-operated rats were controls (n=6). Cell survival was assessed histologically and/or by optical bioluminescence imaging which was conducted using a cooled charged-coupled device camera (Xenogen), beginning on the day after the transplantation. Results: In cell cultures, firefly luciferase activity correlated linearly with cell numbers from 105 to 5x106 (r2=0.95). In living animal imaging, imaging signal activity correlated linearly with cell numbers injected from 105 to 5x106 at each time point (r2=0.62 ~0.98). In all three groups of rats, imaging signal was detected in rat genital area from the 2nd day to the 47th day after cellular injection. Conclusions: Adenovirus mediated transient expression of firefly luciferase reporter gene in ESCs was feasible to monitor cell survival over a month after transplantation. The locations, magnitude, and survival duration of the ESCs were noninvasively monitored with a bioluminescence optical imaging system.
- Society of Nuclear Medicine, Inc.