TY - JOUR T1 - In vivo PET imaging of neuroinflammation response after intravenous transplantation of olfactory ensheathing cells in a hemisection spinal cord injury rat model JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 213 LP - 213 VL - 61 IS - supplement 1 AU - Lijian Zhang AU - Xiaoqing Zhuang AU - Thomas Keller AU - Anna Krzyczmonik AU - Paivi Kotitalo AU - Sarita Forsback AU - Tove Gronroos AU - Chunlei Han AU - Merja Haaparanta-Solin AU - Olof Solin AU - Francisco López Picón AU - Hechun Xia Y1 - 2020/05/01 UR - http://jnm.snmjournals.org/content/61/supplement_1/213.abstract N2 - 213Introduction: In vivo PET imaging of neuroinflammation response after intravenous transplantation of olfactory ensheathing cells in a hemisection spinal cord injury rat model. Objectives: Neuroinflammation is a prominent neuropathological feature of spinal cord injury (SCI). Our previous study showed that intravenous transplantation of olfactory ensheathing cells (OECs) can decrease neuroinflammation after SCI. In this study, in vivo PET/CT imaging and ex vivo spinal cord autoradiography using the TSPO targeting radiotracer [18F]F-DPA (Keller et al., http://dx.doi.org/10.1177/0271678X19853117) was used to image neuroinflammation in a hemisection SCI rat model with and without intravenous transplantation of OECs. Methods: Male Sprague-Dawley rats underwent a lateral hemisection on the twelfth thoracic (T12) vertebra and were randomly divided to OEC group (n = 3/timepoint) and vehicle group (n = 3/timepoint). At 1 day after the surgery, OECs were intravenously transplanted to the OEC rats, while the rats in the vehicle group received culture medium. [18F]F-DPA PET/CT imaging was performed 1, 7, and 14 days after transplantation. The uptake of [18F]F-DPA was quantitatively assessed as standardized uptake value ratio (SUVr), between the mean SUV at the injury region (T11-T13) and the mean SUV at a reference region (C2-C4). After PET imaging, the spinal cord around the injury site was collected for autoradiography analysis. The immunohistochemical studies were performed on the same spinal cord slices to quantify the expression levels of Iba-1 and TSPO. Results: In the OEC group, the SUVr values of [18F]F-DPA decreased with time. In the vehicle group, the SUVr values peaked at 7 days after transplantation. The autoradiography analyses showed that the uptake of [18F]F-DPA in the vehicle group was significantly higher than in the OEC group at 7 days after transplantation (p = 0.025). The expression of Iba-1 and TSPO in the vehicle group was also significantly higher than in the OEC group (p = 0.008; p < 0.0001 respectively). Conclusions: The intravenous transplantation of OECs can mediate activated microglia to inhibit neuroinflammation after SCI. Acknowledgements: This work was supported by the Natural Science Fund of the Ningxia Hui Autonomous Region (2018AAC02012, 2018BCG01002). ER -