18F-FEAU/HSV1-tk PET/CT显像无创性监测iPS细胞移植治疗脊髓损伤的实验研究

脊髓损伤的发生率、致死率和致残率较高，严重威胁人类健康，但由于神经元再生能力的问题，传统的治疗方法作用有限，iPS细胞移植治疗脊髓损伤的前景光明，但缺少有效的疗效评价体系。本研究尝试从分子显像入手，应用成熟的报告基因HSV1-tk，对iPS细胞移植治疗脊髓损伤进行PET/CT动态显像，希望能为脊髓损伤的细胞移植研究提供无创性的评价手段。①体外研究：含HSV1-tk的腺病毒重组体感染体外诱导成功的iPS-NP/S细胞，测定细胞对18F-FEAU的摄取能力；②体内研究：将感染腺病毒重组体的iPS-NP/S细胞移植入大鼠脊髓缺血性损伤模型，评价移植后细胞在体内的分化及大鼠后肢神经功能变化；观察18F-FEAU在活体内的生物学分布，进行PET/CT显像，间接标定iPS-NP/S细胞在损伤脊髓的动态变化，期望为iPS细胞移植治疗脊髓损伤建立一种早期、灵敏、动态、客观、无创的疗效监测方法。

The spinal cord injury is very common disease in the clinical works, which has very high morbility and mortality and have significant risk for humans health worldwide. The traditional methods are unavailability in spinal cord injury because of the prolem of the ability of neuron regenerative. But induced pluripotent stem (iPS) cells are considered as having the greatest potential for use in cell-based therapies for spinal cord injury. So far there is no good method to evaluate the effect of the therapy. This study aim to develop an early, dynamic and non-invasive method to evaluate iPS cell-based therapy effection for spinal cord injury. We transplant iPS-neural precursors/stem into rat spinal cord model and track HSV1-tk (a good report gene in non-invasive gene imaging system based on the molecular imaging) which was expressed in iPS-neural precursors/stem using PET/CT, a high sensitivity and high specificity equipment. ① In vitro study:After successfully induction of hiPS cell culture differentiation to neural cell in vitro, we transfer HSV1-tk gene into hiPS-NP/S using adenovirus and then evaluate the ability of 18F-FEAU uptaken.② In vivo study: We transplant the iPS-NP/S carrying HSV1-tk gene into rat spinal cord injury model, observe neuron differentiation in vivo and animal hind limbs movement function after transplantation. We evaluate the biodistribution of 18F-FEAU in rat spinal cord injury model after the probe of radiopharmaceutical injection. We observe the dynamic distribution of iPS-NP/S cell in spinal cord injury animal model through PET/CT procedure and develop an early, sensitive, dynamic, objective and non-invasive detectation method for cell transplantation therapy.