早老性痴呆模型细胞移植的正电子发射计算机断层显像

目的 探讨2-(4'-N-11C-甲胺基苯)-6-羟基苯丙噻唑(11C-PIB)和18F-脱氧葡萄糖(18F-FDG)正电子发射计算机断层显像(PET)在模型验证及监测移植细胞中的应用价值.方法 建立Aβ(1-40)海马注射痴呆模型后进行细胞移植,通过行为学、组织学检测及11C-PIB PET和11F-FDG小动物PET显像,观察显像结果是否与行为学、组织学结果相匹配.结果 模型组在Morris水迷宫中的潜伏期显著长于正常组(P<0.01),组织学显示海马CA,及齿状回出现神经元丢失和AB沉积11C-PIB显像中模型组海马区域PIB放射性摄取显著增高(P<0.05),18F-FDG显像中模型组注射侧海马放射性摄取显著低于正常组的同侧(P<0.001).细胞移植后移植组潜伏期较模型组减少33.7%～51.5%(P<0.01),组织学显示Aβ沉积无明显改变,神经干细胞分化表达神经元核蛋白阳性细胞,并持续6周表达5-溴脱氧尿苷阳性细胞,11C-PIB显像显示移植组与模型组放射性摄取差异无显著性(P>0.05),18F-FDG显像显示移植组与模型组放射性摄取基本一致(P>0.05).结论 11C-PIB PET成像有助于诊断早老性痴呆并活体监测模型大鼠脑内的淀粉样斑块,而18F-FDG在监测移植细胞短期疗效方面存在局限性.

Positron Emission Tomography Imaging of Cell Transplantation in A Rat Model of Alzheimer's Disease

Objective To explore the value of positron emission tomography (PET) in the Alzheimer's disease ( AD) rat model verification and in monitoring the therapeutic effectiveness of cell trans-plantation. Methods Af(1-40) hippocampus injected rat model was successfully established and neural stem cells were injected into hippocampus. Results of behavior tests and histological examinations were compared be- tween model group and graft group, and then the N-methyl- [11G] 2- (4'methylaminophenyl)-6-hydroxy-benzothiazole (11C-PIB) and 18F-fluorodeoxyglucose (18F-FDG) imaging were performed to observe whether the result of imaging was matched with behavior test and histological examination. Results The Morris water maze showed that the latent period of the escape was significantly longer in model group than in control group (P<0. 01). In histological examinations, the neuron loss and Aβ deposition were found in hippocampus CA1 and dentate gyms of rat model. 11C-PIB imaging showed increased uptake in model rat hippocampus district (P < 0. 05) , while 18F-FDG imaging showed that the uptake in the injected side of hippocampus in model group was significantly lower than that in the same side in control group (P <0. 001). After cell transplantation, the la-tent period of the escape was significantly shorter in graft group than in model group (P <0. 01). Histological examinations showed that there was no obvious changes in Aβ deposition; in addition, the neural stem cells dif-and expressed neuronal nuclei-positive cells, and continuously expressed 5-bromodeoxyuridine-posi-tive cells for six weeks.11 C-PIB imaging and 11F-FDG imaging showed the uptakes were not significantly differ-ent between between model group and transplantation group ( P > 0.05). Conclusion 11 C-PIB imaging is useful in diagnosing AD and monitoring the pathological change of AD model in vivo, while18F-FDG imaging provides useful visual information for monitoring short-term therapeutic effectiveness of stem cell transplantation.