Abstract
1137
Objectives: Monitoring stem cells in vivo remains problematic owing to limitations of conventional histological assays and imaging modalities. This study was to in vivo visualize neural stem cell (NSCs) grafts based on microPET molecular imaging. Methods: The cDNA of hDRD2 (human dopamine receptor 2) was cloned by RT-PCR, and inserted into the MCS of pcDNA3.1(+) plasmid. Mediated by the Effectene transfection reagent, the neural stem cells were transfected with this recombinant plasmid pcDNA3-DRD2. Then RT-PCR, Western blotting and immunocytochemistry were performed to detect the expression of hDRD2 in stem cells. Neural stem cells were then labeled with BrdU the day before transplantation. Six rabbits were divided into transplantation and control groups (n=3).All of them were subjected to focal traumatic brain injury in right parietal lobe. For the transplantation group neural stem cells (1×106) were transplanted into the right parietal lobe, Saline were injected for the control group. At different stages (prior and post trauma, post-transplantation), microPET scan was performed to detect the expression of DRD2 molecule and the regional glucose metabolism in the brain, with 11C-NMSP and 18F-FDG respectively and the behavior capability was also evaluated. Two weeks after transplantation, The survival and gene expression of donor neural stem cells were analyzed by immunoflourescence staining for BrdU and DRD2. Results: Neural stem cells were transfected successfully and highly expressed DRD2.The expression of DRD2 increased from 3.2 ID%/g to 5.3 ID%/g at one day and seven days after NSCs transplantation (P<0.05 versus control). Both rCMRglu and DRD2 expression of traumatic brain increased progressively at the different time stage after NSCs transplantation, which indicated NSCs survival in the host. Immunofluorescence staining finding also showed that donor neural stem cells survived in the traumatic brain and even expressed DRD2 2 weeks after transplantation. Conclusions: This study showed that NSCs graft can highly express PET reporter gene and can monitor the kinetics of NSCs survival in vivo.
- Society of Nuclear Medicine, Inc.