He Yihua, Peng Yuqin, Chang Yuan, Zhu Juan, Li Zheqi, Huang Kaibin, Pan Suyue
Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, 510000, China.
J Radiat Res. 2021 Sep 28. doi: 10.1093/jrr/rrab086.
Radiation-induced brain injury (RBI) is a common complication of radiotherapy for head and neck tumors while its mechanism is not fully understood. Animal whole-brain radiation (WBR) models are of key importance in experimental radiation research, and an appropriate radiation source is essential. Previous animal WBR models were administered by clinical linear accelerator to induce the pathophysiological changes of RBI. In the current study, we adopted Faxitron MultiRad 225 X-ray irradiation system to construct a mouse WBR model with a single dose of 30 Gy. In the acute phase of this mouse WBR model, brain edema and blood-brain barrier (BBB) damage were found mild. However, two months later, the results of immunofluorescence showed that astrocytes and microglia were activated continuously, and the number of immature neurons in dentate gyrus (DG) area of hippocampus was significantly reduced, in accordance with the features of chronic pathophysiological changes. Besides, data of MRI scans and behavior tests illustrated the structural changes of brain tissue and cognitive impairment in the chronic phase. To sum up, this mouse WBR model using the Faxitron MultiRad 225 irradiation system with a single dose of 30 Gy is feasible to simulate the RBI-related chronic pathophysiological changes.
放射性脑损伤（RBI）是头颈部肿瘤放疗常见的并发症，但其机制尚未完全明确。动物全脑照射（WBR）模型在实验性放射研究中至关重要，合适的辐射源必不可少。以往的动物WBR模型采用临床直线加速器进行照射以诱导RBI的病理生理变化。在本研究中，我们采用Faxitron MultiRad 225 X射线照射系统构建了单次剂量30 Gy的小鼠WBR模型。在该小鼠WBR模型的急性期，发现脑水肿和血脑屏障（BBB）损伤较轻。然而，两个月后，免疫荧光结果显示星形胶质细胞和小胶质细胞持续激活，海马齿状回（DG）区域未成熟神经元数量显著减少，符合慢性病理生理变化的特征。此外，MRI扫描和行为测试数据表明了慢性期脑组织的结构变化和认知障碍。综上所述，采用Faxitron MultiRad 225照射系统、单次剂量30 Gy的该小鼠WBR模型可用于模拟与RBI相关的慢性病理生理变化。
