【摘要】 探讨电离辐射引起小鼠认知功能障碍的可能机制。24只雌性昆明小鼠随机分为对照组和辐照组,辐照组小鼠接受137Csγ射线单次全身辐照至吸收剂量4 Gy。35 d后采用Y迷宫实验检测小鼠认知功能;免疫组织化学法检测小鼠海马区星形胶质细胞(Astrocytes,Ast)标记物胶质纤维酸性蛋白(Glial fibrillary acidic protein,GFAP)阳性细胞数的表达变化;Western blot方法检测海马GFAP蛋白的表达变化;荧光定量PCR检测炎性因子白细胞介素IL-1α、IL-1β、IL-6 mRNA和海马GFAP的表达情况。结果表明:与对照组相比,辐照组小鼠在Y迷宫实验中自发交替率明显降低(78.40±4.16 vs. 67.53±3.08,p<0.05);海马区GFAP阳性细胞数明显增加(133.4±9.6 vs. 280.3±32.7,p<0.01);GFAP蛋白及mRNA表达均显著上调(1.000±0.036vs. 1.300±0.102,p<0.05;1.000±0.031 vs. 1.203±0.078,p<0.05);IL-1α、IL-1β和IL-6 mRNA的表达均明显上调(1.000±0.133 vs. 1.677±0.164,p<0.01;1.000±0.132 vs. 1.488±0.105,p<0.05;1.000±0.218 vs.2.181±0.188,p<0.01)。研究提示,电离辐射可能是通过激活海马Ast诱导炎症因子释放,从而引起认知功能障碍。更多还原

【Abstract】 In order to explore the possible mechanisms underlying cognitive dysfunction induced by ionizing radiation in mice, twenty-four female Kunming mice were randomly divided into a control group and irradiation group(IR). The IR group mice were irradiated with137 Cs γ-rays at an absorbed dose of 4 Gy. After 35 d, the Y-maze test was used to evaluate the cognitive function of the mice. The expression of the astrocyte marker, glial fibrillary acidic protein(GFAP), was detected using immunohistochemical staining. The expression of GFAP protein in the hippocampus was assayed using western blot. The expression of GFAP, interleukin(IL)-1α, IL-1β, and IL-6 mRNA in the hippocampus was detected using reverse transcription polymerase chain reaction. The results showed that compared with the control group, the spontaneous alternation rate of the IR mice was significantly reduced in the Ymaze test(78.40 ± 4.16 vs. 67.53 ± 3.08, p < 0.05); and the number of GFAP-positive cells in the hippocampus was significantly higher(133.4 ± 9.6 vs. 280.3 ± 32.7, p < 0.01); GFAP protein levels(1.000 ± 0.036 vs. 1.300 ± 0.102, p<0.05) and GFAP mRNA expression(1.000 ± 0.0307 vs. 1.203 ± 0.078, p < 0.05) were significantly upregulated;and the expression of inflammatory factors IL-1α, IL-1β, and IL-6 mRNA was upregulated(1.000 ± 0.133 vs 1.677 ±0.164, p < 0.01; 1.000 ± 0.132 vs. 1.488 ± 0.105, p < 0.05; 1.000 ± 0.218 vs 2.181 ± 0.188, p < 0.01). It is suggested that ionizing radiation induces cognitive dysfunction by activating astrocytes in the hippocampus.更多还原