目的探讨切割穹隆海马伞大鼠海马胆碱能神经再生过程中Lhx8的作用。方法72只SD大鼠随机分成4组,每组18只。所分的4组分别为:对照组(未做任何处理),切割组(切割右侧穹隆海马伞),过表达组(右侧海马齿状回中注射Lenti6.3-Lhx8慢病毒)及切割联合过表达组(右侧海马齿状回中注射Lenti6.3-Lhx8慢病毒并切割右侧穹隆海马伞)。28d后每组各取6只分别制备脑冷冻切片行免疫荧光检测,提取海马总RNA行Real—time PCR,提取海马蛋白行Western blotting检测。结果与对照组相比,切割组、过表达组和切割联合过表达组中Lhx8mRNA和蛋白水平均显著上调,以切割联合过表达组中上调最为显著,组间比较差异均有统计学意义;切割组胆碱乙酰转移酶(CHAT)mRNA水平与对照组相比无统计学差异,过表达组和切割联合过表达组中ChAT mRNA显著上调,且以切割联合过表达组中上调最为显著;切割组、过表达组和切割联合过表达组中均检测到ChAT蛋白,组间比较差异有统计学意义;切割组、过表达组和切割联合过表达组海马齿状回门区和颗粒下层中均能检测到新生的Lhx8阳性的胆碱能神经元,且以切割联合过表达组最多,组间比较差异均有统计学意义。结论上调Lhx8的表达能促进海马中神经干细胞向胆碱能神经元分化,Lhx8可能与海马胆碱能神经再生有关。
Objective To investigate the effect of Lhx8 in hippocampal cholinergic neural regeneration of SD rat after fimbria-fornix transection. Methods According to the different treatments, 72 SD rats were randomly divided into four groups: the normal group, the transected group, the overexpressed group and the transected combined with overexpressed group. On the 28th day after treatments, the sections of rat hippocampus of each group were prepared and stained with immunohistochemieal methods to detect the number of newborn Lhx8 and ChAT positive cells. PCR and Western blotting were performed after total RNA and protein of hippocampus were obtained respectively. Results Compared with the normal group, the levels of Lhx8 mRNA and protein were significantly increased in other three groups and the differences were significant among the groups. No significant difference of the levels of ChAT mRNA was observed between the normal group and the transeeted group while it was significantly upregulated in the overexpressed and the transected combined with overexpressed groups. ChAT protein was detected in the transected, overexpressed and the transected combined with overexpressed groups and the differences were significant among the groups. There were newborn Lhx8 positive cholinergic neurons in hilus and subgranular zone of hippocampal dentate gyrus in the transected, overexpressed and the transected combined with overexpressed groups, with the most in the transected combined with overexpressed group, and the differences were significant among the groups. Conclusion Upregulation of Lhx8 can promote differentiation of neural stem cells into cholinergic neurons in hippocampus significantly, and Lhx8 may be related to cholinergic neural regeneration of hippocampus.