切割穹窿海马伞大鼠海马内BLBP的表达变化

The change of BLBP expression in rat hippocampus after the fimbria/fornix transection

为了观察切割大鼠右侧穹窿海马伞后,切割侧与正常侧海马齿状回内脑脂结合蛋白(BLBP)的表达变化,本研究应用Western blot和免疫组织化学方法检测双侧海马内BLBP蛋白表达水平的变化,以及海马齿状回门区和颗粒下层中BLBP免疫阳性细胞数和灰度值。结果显示:正常大鼠双侧海马各区和颗粒下层细胞BLBP仅有微量表达,切割穹窿海马伞后第1 d双侧差异不明显;3 d时切割侧颗粒下层阳性细胞及染色深度较正常侧加深;5 d时切割侧颗粒下层阳性细胞数量明显增多,染色较深,并达到最高水平;7 d后BLBP免疫阳性细胞的数量和染色深度开始降低,14 d时接近正常侧水平。而切割后3、5 d时双侧门区BLBP免疫阳性细胞的数量差异不大,但切割侧染色较深,7 d后也逐渐降低,14 d时降至正常侧水平。上述结果提示,切割穹窿海马伞阻断了隔区与海马齿状回的纤维联系后,可引起海马齿状回门区和颗粒下层BLBP表达增强,可能引发了放射状胶质细胞的增殖和激活,构成的支架有助于神经干细胞的迁移和向神经元的分化。

To observe the change of the brain lipid binding protein （BLBP） expression in dentate gyms（DG） region of transected and normal hippocampus after the right side of rats＇ fimbria/fornix transection, Western blot and immunohistochemical methods were used to detect not only the variety of BLBP protein expression in both sides, but also the number and gray scale of BLBP positive cells in hilus and subgranular layer of dentate gyrns. The present results showed that few BLBP-immunopositive ceils were expressed in both sides of each region and subgranular layer of hippoeampus in control group. After the fimbria/fornix transection, no significant difference was observed in both sides on the 1 st day. Compared with the normal side, more BLBP-immunopositive cells with deeper staining were found in the subgranular layer of the transeeted side on the 3rd day. The number and the color of the BLBP-immunopositive cells in the subgrauular layer of transected side were detected much more than those in the normal side and appeared to the peak on the 5th day. Then it started to decrease 7 days later and closed to the normal level on the 14th day. But, the number of the BLBP-immunopositive cells showed little difference in both sides of hilus on the 3rd and 5th day after transection, while the color was more deeper in the fimhria transected side. 7 days later, it also decreased slowly to pre-transeetion level on day 14. The above results indicate that blocked the fiber connection from septal area to dentate gyrns of hippoeampus can cause the expressional enhancement of BLBP-immunoreaetivity in hilus and subgranular layer of dentate gyrus, which may induce the activation and proliferation of radial gila cells, and form the scaffolds which conduce to the neural stem cells migration and the differentiation to the neurons.