title: PET demonstrates functional recovery after transplantation of induced pluripotent stem cells in a rat model of cerebral ischemic injury.
abstract: The purpose of this study was to determine the functionality of the transplanted induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) in a rat model of cerebral ischemia with use of (18)F-FDG small-animal PET imaging.
  
  
  METHODS
  Middle cerebral artery occlusion was used to establish cerebral ischemia. Twenty-four male rats were randomly assigned to 1 of 3 groups: iPSC treatment, ESC treatment, and the control phosphate-buffered saline (PBS) injection. After neurologic function tests and baseline (18)F-FDG small-animal PET had been performed, 1.0 × 10(6) suspended iPSCs or ESCs were injected stereotactically into the left lateral ventricle. The treatment response was evaluated weekly by (18)F-FDG PET scans and neurologic function tests. Histologic analyses and autoradiographic imaging were performed 4 wk after stem cell transplantation.
  
  
  RESULTS
  Compared with the PBS injection group, higher (18)F-FDG accumulation in the ipsilateral cerebral infarction was observed in both the iPSC and the ESC treatment groups during the 4-wk period (P < 0.05). (18)F-FDG accumulation in the ipsilateral cerebral infarction increased steadily over time in the iPSC treatment group. At 1 and 2 wk after stem cell transplantation, significant recovery of glucose metabolism was found in the ESC treatment group (P < 0.05) and then decreased gradually. The neurologic score in both stem cell-treated groups was significantly lower than that in the PBS group, indicating functional improvement. Immunohistochemical analysis demonstrated that transplanted stem cells survived and migrated close to the ischemic region, and most of the stem cells expressed protein markers for cells of interest.
  
  
  CONCLUSIONS
  (18)F-FDG small-animal PET demonstrated metabolic recovery after iPSC and ESC transplantation in the rat model of cerebral ischemia. iPSCs could be considered a potentially better therapeutic approach than ESCs and are worthy of further translational investigation.
authors.affiliation: Department of Nuclear Medicine, Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Jiachuan
authors.initials: J
authors.lastname: Wang
authors.forename: Fangfang
authors.initials: F
authors.lastname: Chao
authors.forename: Feng
authors.initials: F
authors.lastname: Han
authors.forename: Gensheng
authors.initials: G
authors.lastname: Zhang
authors.forename: Qunying
authors.initials: Q
authors.lastname: Xi
authors.forename: Jinhui
authors.initials: J
authors.lastname: Li
authors.forename: Han
authors.initials: H
authors.lastname: Jiang
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
authors.forename: Mei
authors.initials: M
authors.lastname: Tian
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D004195:Disease Models, Animal; D053595:Embryonic Stem Cells / Q000637:transplantation; D019788:Fluorodeoxyglucose F18; D057026:Induced Pluripotent Stem Cells / Q000637:transplantation*; D008297:Male; D049268:Positron-Emission Tomography; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D033581:Stem Cell Transplantation
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: cerebral ischemia; induced pluripotent stem cells; positron emission tomography (PET); transplantation