^(60)Co γ射线全身照射致小鼠脑损伤中小胶质细胞和巨噬细胞极化模式研究  

Effects of ^(60)Co γ-rays on brain injury and polarization of microglia/macrophages in mice

作　　者：王学立 杜秋丽 李志慧 周森 董国福 王长振 Wang Xueli;Du Qiuli;Li Zhihui;Zhou Sen;Dong Guofu;Wang Changzhen(School of Chemistry and Environmental Sciences,Hebei University,Baoding 071002,China;Institute of Radiation Medicine,Academy of Military Medical Sciences,Academy of Military Sciences,Beijing 100850,China;School of Life Sciences and Bioengineering,Jining College,Jining 273155,China)

机构地区：[1]河北大学化学与环境科学学院,保定071002 [2]军事科学院军事医学研究院辐射医学研究所,北京100850 [3]济宁学院生命科学与生物工程学院,济宁273155

出　　处：《中华微生物学和免疫学杂志》2022年第7期501-509,共9页Chinese Journal of Microbiology and Immunology

摘　　要：目的探究高、低剂量电离辐射全身照射后短时间内小鼠海马组织损伤规律,分析小胶质细胞和巨噬细胞极化模式在损伤中的作用。方法C57BL/6小鼠随机分为假照射组、低剂量组(0.05 Gy)、高剂量组(7 Gy),低、高剂量组分别进行单次^(60)Co γ射线的全身照射;于照射后6 h、1 d、3 d、7 d取小鼠海马组织,采用HE和尼氏(Nissl)染色法检测神经元形态结构,Tunnel染色法检测神经细胞凋亡,RT-PCR和免疫荧光试验分别检测海马区M1和M2型小胶质细胞标记物mRNA和蛋白质表达水平及分布规律;在照射后1个月,分别采用水迷宫、旷场、高架十字迷宫以及悬尾试验评估小鼠认知和情绪行为。结果病理学检测结果显示,辐射后小鼠海马区神经细胞形态结构改变,并伴随凋亡现象。^(60)Co γ射线照射后6 h出现急性损伤,1 d、3 d有所缓解,7 d损伤持续存在,且呈剂量依赖性。免疫荧光染色结合共聚焦成像分析结果显示,与假照射组相比,7 Gy ^(60)Co γ射线照射后6 h、1 d小鼠海马区小胶质细胞数量显著增加,M1型小胶质细胞标志物表达下调,M2型小胶质细胞标志物表达呈上调趋势,而在辐射后3 d和7 d,M2型小胶质细胞标志物出现降低趋势。RT-PCR结果显示,照射组M1和M2型小胶质细胞标志物基因mRNA表达水平在照射后6 h有上调趋势,但无统计学意义,相关促/抗炎因子mRNA表达水平明显上调。行为学试验结果显示,与对照组比较,照射后1个月小鼠在行为和情绪上差异均无统计学意义。结论^(60)Co γ射线照射后可导致小鼠出现海马组织损伤,海马内小胶质细胞和巨噬细胞过表达并呈现不同极化状态。Objective To analyze the damage in hippocampal tissues of mice after whole-body irradiation with high-or low-dose ionizing radiation and to investigate the roles of microglia/macrophages polarization in the injury.Methods C57BL/6 mice were randomly divided into three groups:sham irradiation group,low-dose group(0.05 Gy)and high-dose group(7 Gy).Low-and high-dose groups were respectively treated by whole-body irradiation with single dose of ^(60)Co γ-rays.Hippocampal tissues of the mice were collected at 6 h,1 d,3 d and 7 d after irradiation.The morphology,structure and apoptosis of neurons were detected by HE staining,Nissl staining and Tunnel staining,respectively.RT-PCR and immunofluorescence assay were performed to detect the expression of M1 and M2 microglial markers at mRNA and protein levels in hippocampus tissues.The cognitive and emotional behaviors of mice were evaluated one month after the irradiation by Morris water maze,open field test,elevated plus maze and tail suspension test.Results There were morphological and structural changes in the nerve cells in the hippocampus region of mice after irradiation,accompanied by apoptosis.Acute injuries occurred at 6 h after radiation,alleviated at 1 d and 3 d,and persisted at 7 d in a dose-dependent manner.The results of immunofluorescence staining and confocal imaging analysis showed that compared with the sham irradiation group,the high-dose group showed increased number of microglia,down-regulated expression of M1 microglial markers and up-regulated expression of M2 microglial markers in the hippocampus at 6 h and 1 d after radiation,while M2 microglial markers decreased at 3 d and 7 d after irradiation.PCR results showed that the expression of M1 and M2 microglial markers at mRNA level in the irradiation groups increased at 6 h after irradiation,but there was no statistical significance.The expression of related proinflammatory/anti-inflammatory factors was significantly up-regulated.The results of behavioral experiments showed that compared with the sham

关 键 词：^(60)Coγ射线 海马 小胶质细胞 认知情绪 

分 类 号：R816[医药卫生—放射医学]