Liver localization of bone marrow mesenchymal stem cells in rat after orthotopic liver transplantation.

Objective To track CFSE and Brdu labeled bone marrow mesenchymal stem cells (MSCs) in rat after orthotopic liver transplantation. Method Orthotopic liver transplantation model was established using DA to Lewis rats with "the two-cuff technique". MSCs from the bone marrow were labeled with CFSE and Brdu. The cells were then infused into recipient rat through portal vein after liver transplantation..The rate were killed and the livers were examined at day-1,day-7,day-14,1 month and 2 months after transplantation. Transplanted MSCs were identified by fluorescence microscopy and immunohistochemical methods in liver tissue sections. Result The labeling efficiency of CFSE and Brdu was (94.1±1.4)% and (90.3±3.5)% , respectively. CSFC labeled MSCs were still detected at day-14 after injection and the fluorescence signal disappeared over 21 days. CFSE labeled MSCs in control rats were not detected after 5 days of transplantation. Brdu labeled MSCs were still detected at 2 months after transplantation. In contrast, Brdu labeled MSCs were not seen in the control rats. Conclusion Both CFSE and Brdu can label MScs. CFSE is suitable for short term tracking of the labeled cells. As Brdu has a longer retention time in cells, Brdu is suitable for a long time tracking. We conclude that CFSE and Brdu can be used for fluorescent labeling of MSCs. Using these labeling methods, MSCs were found to localize in the transplanted liver.