氯化锂匹罗卡品诱导癫痫大鼠海马神经元GPER1表达的变化

The change of GPER1 expression in hippocampal neurons of lithium-pilocarpine in induced epileptic rats

目的:观察G蛋白偶联雌激素受体1(GPER1)在癫痫大鼠海马神经元中表达的变化。方法:成年雄性SD大鼠分成对照组(control)和癫痫组(epilepsy),利用腹腔注射氯化锂-匹罗卡品方法制备癫痫模型,分别在1、2、3、7、14 d和28 d,利用Morris水迷宫检测大鼠学习记忆能力,利用尼氏染色观察大鼠海马神经元形态变化;利用免疫组化和Western Blot技术观察GPER1在海马的表达。结果:水迷宫结果显示,与Control组相比,造模14 d的大鼠逃逸潜伏时间明显延长(P <0. 05),穿越目标象限区域的次数较Control组显著降低(P <0. 05)。尼氏染色结果显示:与Control组相比,造模1 d和2 d的大鼠CA1及CA3区锥体细胞层细胞及DG区颗粒细胞层细胞体积缩小,细胞间距增加,尼氏染色减弱;造模3和7 d的大鼠细胞体积明显缩小,细胞间隙明显增大,尼氏染色加深,CA1及CA3细胞数量明显减少;造模14 d和28 d的大鼠神经元体积逐渐向正常恢复,但仍较Control组小。免疫组化结果显示:GPER1免疫阳性细胞以海马锥体细胞和齿状回颗粒细胞为主,主要分布在细胞膜。与Control组相比,造模2 d和3 d的大鼠海马CA1及CA3区GPER1表达增加(P <0. 05),7 d后增加最明显(P <0. 01),14、28 d后表达下降;在DG区,造模3 d及7 d的大鼠GPER1表达增加(P <0. 05),14 d后表达下降(P <0. 05),28 d大鼠无显著差异。Western Blot结果显示:与Control组比较,造模2 d和3 d的大鼠GPER1相对表达量开始增高,7 d后明显增高(P <0. 05),14 d及28 d的大鼠表达降低。结论:GPER1在海马神经元的表达随着神经元损伤的加重而增高,随着神经元损伤的恢复逐渐降低,提示其表达变化与神经元的损伤与修复有关。

Objective: To observe the change of G protein-coupled estrogen receptor 1(GPER1) expression in hippocampal neurons of epileptic rats. Methods: Adult male SD rats were divided into Control group and epilepsy(EP)group. The EP model was prepared by intraperitoneal injection of lithium-pilocarpine,morris water maze was used to test the learning and memory ability in rats after EP 1,2,3,7,14 d and 28 d;The change of hippocampal neurons were observed by Nissl staining;The expression of GPER1 in hippocampus was observed by immunohistochemistry and Western Blot. Results: The results of water maze showed that compared with the Control group,the time of escape latency was significantly longer(P < 0. 05),and the number of passes through the target quadrant area was significantly lower(P < 0. 05) after EP 14 d. Nissl staining results showed that compared with the Control group,the cells in the pyramidal cell layer of CA1 and CA3 regions and the granulosa cell layer of DG region decreased after EP 1 d and 2 d,the intercellular space increased and the color of Nissl staining decreased. After EP 3 d and 7 d,the size of the cells decreased obviously,the intercellular space increased obviously,the Nissl staining deepened and the numbers of CA1 and CA3 cells decreased obviously. The volume of neurons after EP 14 d and 28 d gradually recovered to normal,but it was still smaller than that in the Control group. Immunohistochemistry results showed that the positive cells of GPER1 were mainly hippocampal pyramidal cells and dentate gyrus granulosa cells and the positive staining was mainly in cytomembrane. Compared with the Control group,the optical density ratio of GPER1 positive cells increased in CA1 and CA3 areas after EP 2 d and 3 d(P < 0. 05),increased significantly after EP 7 d(P < 0. 01) and decreased after EP 14 d and 28 d. In DG region,the ratio of optical density of positive cells increased after EP 3 d and 7 d(P < 0. 05),decreased after EP 14 d(P < 0. 05) and there was no significant difference after EP 28 d. Western Blot results showed that compared with the Control group,the relative expression of GPER1 began to increase after EP 2 d and 3 d,increased significantly after EP 7 d(P < 0. 05),and decreased after EP 14 d and 28 d. Conclusion: The expression of GPER1 in hippocampal neurons increases with the aggravation of neuronal injury and decreases with the recovery of neuronal injury,which suggesting that the expression of GPER1 is related to the injury and repair of neurons.