Tracking GFP-labeled Transplanted Mouse MSC in Nude Mice Using in Vivo Fluorescence Imaging

73 Introduction Stem cell therapy is now considered as a new therapeutic method to restore damaged organ including injured liver [1]. One important source of stem cells is mesenchymal stem cells (MSC) [2]. MSC can be easily collected from bone marrows of patients [3]. MSC is chemotactic to damaged organs and tissues which often secret cytokines and chemokines [4]. Subsequently, MSC can settle and multiply in the damaged zones (namely, by homing phenomenon), and often heal the damaged or inflamed organ and tissues [5]. This phenomenon has, however, not well been understood, yet. The fluorescent nature of the cells from green fluorescent protein (GFP)-transgenic mice facilitate the use in many kinds of cell transplantation experiments [6]. Immunitycompromised mice (nude mice) have been used as host animal so that the relation between transplanted GFP-transgenic mouse cells and host nude mouse body could be clarified [7]. The purpose of this study was, therefore, to monitor the fate of GFP-labeled transgenic Tracking GFP-labeled Transplanted Mouse MSC in Nude Mice Using in Vivo Fluorescence Imaging