氚照射对大鼠海马神经细胞黏附分子L1、NCAM表达的影响

Effects of irradiation from tritiated water on the expression of neural cell adhesion molecule L1 and NCAM of hippocampus in rats

目的探讨低剂量氚照射对大鼠海马神经细胞黏附分子L1、神经细胞黏附分子(NCAM)表达的影响。方法取24 h新生鼠脑海马细胞培养,培养第7天以3.7×102、3.7×103、3.7×104、3.7×105、3.7×106Bq/ml终浓度氚水照射细胞24 h,并设对照组(0 Bq/ml),活细胞工作站测定各处理组细胞的迁移距离;Western blot法、免疫细胞化学法检测各浓度氚水照射下神经细胞黏附分子L1及NCAM蛋白的表达情况。结果神经细胞迁移距离测定结果显示,与对照组相比,受照组细胞迁移距离明显缩短,且随着氚水浓度的不断增加而逐渐缩短(P<0.05);Western blot法、免疫细胞化学法检测显示受照组神经细胞黏附分子L1、NCAM蛋白表达含量均低于对照组,并随氚水浓度的升高表达量呈递减趋势(P<0.05)。结论氚照射可致神经细胞黏附分子表达量减少进而可影响神经细胞的正常迁移。

Objective To explore the effects of low concentrations of tritium irradiation using tritiated water on the expression of neural cell adhesion molecule L1 （L1） and neural cell adhesion molecule （NCAM） in vitro. Meth-ods Hippocampal neuron cells from neonatal Sprague-Dawley （SD） rats （24 h） were primarily cultured in DMEM for 7 d, followed by exposure to tritiated water at concentrations of 3. 7 × 102 , 3. 7 × 103 , 3. 7 × 104 , 3. 7 × 105 , 3. 7 × 106 Bq / ml for 24 h respectively, and cells without tritium irradiation served as control group （0 Bq / ml）. Live Cell Imaging System was performed to detect neuronal migration capacity. Western blot and immunocytochemistry （ICC） were used to measure the expression levels of neural cell adhesion molecule L1 and NCAM. Results The migration distance of irradiated neural cells was significantly shorter than that of the control group and declined gradually with increasing tritiated water （HTO） concentrations （P 〈 0. 05）; Western blot and ICC showed that the expression of L1 and NCAM were both presented a dose-dependent decrease in hippocampal neuron cells when irra-diated by tritium （P 〈 0. 05）. Conclusion Neurons exposed to tritium irradiation are probably undergoing the de-creased expression of neural cell adhesion molecules, further leading to abnormal neuronal migration.