title: Optical imaging for stem cell differentiation to neuronal lineage.
abstract: In regenerative medicine, the prospect of stem cell therapy holds great promise for the recovery of injured tissues and effective treatment of intractable diseases. Tracking stem cell fate provides critical information to understand and evaluate the success of stem cell therapy. The recent emergence of in vivo noninvasive molecular imaging has enabled assessment of the behavior of grafted stem cells in living subjects. In this review, we provide an overview of current optical imaging strategies based on cell- or tissue-specific reporter gene expression and of in vivo methods to monitor stem cell differentiation into neuronal lineages. These methods use optical reporters either regulated by neuron-specific promoters or containing neuron-specific microRNA binding sites. Both systems revealed dramatic changes in optical reporter imaging signals in cells differentiating into a neuronal lineage. The detection limit of weak promoters or reporter genes can be greatly enhanced by adopting a yeast GAL4 amplification system or an engineering-enhanced luciferase reporter gene. Furthermore, we propose an advanced imaging system to monitor neuronal differentiation during neurogenesis that uses in vivo multiplexed imaging techniques capable of detecting several targets simultaneously.
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Seoul National University, 28 Yongon-Dong, Jongno-Gu, Seoul, 110-744 Korea ; Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Do Won
authors.initials: DW
authors.lastname: Hwang
authors.affiliation: Department of Nuclear Medicine, College of Medicine, Seoul National University, 28 Yongon-Dong, Jongno-Gu, Seoul, 110-744 Korea ; WCU, Department of Molecular Medicine and Biopharmaceutical Science, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
keywords: Differentiation imaging; Multiplex imaging; Neuronal differentiation; Neuronal microRNA; Reporter-based cell tracking