title: In vivo imaging of engrafted neural stem cells: its application in evaluating the optimal timing of transplantation for spinal cord injury.
abstract: Neural stem/progenitor cells (NSPCs) hold promise in neural tissue replacement therapy after spinal cord injury. However, understanding the survival time of grafted NSPCs and determining the extent of migration away from transplantation sites are essential for optimizing treatment regimens. Here, we used in vivo bioluminescence imaging to noninvasively assess the survival and residence time of transplanted NSPCs at the injury sites in living animals, and we used histologic analyses to assess cell integration and morphology. Third-generation lentiviral vectors enabled efficient transduction and stable expression of both luciferase and a variant of green fluorescent protein in primary cultured NSPCs. Signals from these cells were detectable for up to 10 months or more after transplantation into the injured spinal cords of C57BL/6J mice. Histological and functional data supported the imaging data and suggest that the timing of NSPC transplantation may be a key determinant of the fates and function of integrated cells since cell survival and migration depended on the time of transplantation relative to injury. Optimization of cell therapies can be greatly accelerated and refined by imaging, and the methods in the present study can be widely applied to various research fields of regeneration medicine, including transplantation study.
authors.affiliation: Department of Physiology, Keio University School of Medicine, Shinjuku, Tokyo, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Okada
authors.forename: Ken
authors.initials: K
authors.lastname: Ishii
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamane
authors.forename: Akio
authors.initials: A
authors.lastname: Iwanami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ikegami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Katoh
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Nakamura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Miyoshi
authors.forename: Hirotaka James
authors.initials: HJ
authors.lastname: Okano
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Contag
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okano
mesh_terms: D000818:Animals; D002465:Cell Movement; D002470:Cell Survival; D002478:Cells, Cultured; D005260:Female; D017930:Genes, Reporter; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000378:metabolism; D007150:Immunohistochemistry; D016086:Lentivirus / Q000235:genetics; D008156:Luciferases / Q000378:metabolism; D008164:Luminescent Proteins / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008957:Models, Genetic; D009474:Neurons / Q000166:cytology*; D012038:Regeneration; D013116:Spinal Cord / Q000378:metabolism / Q000637:transplantation*; D013119:Spinal Cord Injuries / Q000628:therapy*; D033581:Stem Cell Transplantation / Q000379:methods*; D013234:Stem Cells / Q000166:cytology*; D013997:Time Factors
chemical_list: D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D008156:Luciferases