Noggin参与海人酸损伤后成年大鼠海马颗粒下区颗粒细胞增殖

目的 探讨侧脑室注射海人酸(KA)致大鼠海马损伤后Noggin的表达变化及其与颗粒细胞增殖的关系.方法 健康雄性SD大鼠32只采用随机数字表法分为实验组(16只)及对照组(16只).对照组又分为生理盐水对照组和空白对照组,各8只.实验组大鼠侧脑室注射KA,生理盐水对照组注射等剂量生理盐水.空白对照组不作处理.侧脑室注射KA 1周内,尼氏染色检测海马神经元的丢失.免疫荧光染色与原位杂交的方法检测海马齿状回BrdU标记细胞与Noggin mRNA阳性细胞的变化.结果 在侧脑室注射KA致海马损伤后1周,海马CA3、CA4区神经元丢失明显.与生理盐水对照组比较,实验组海马齿状回BrdU阳性细胞升高,差异有统计学意义(P=0.006),其中注射侧较对侧更为明显.海马Noggin mRNA阳性细胞在第3天时升高,第7天时下降.结论 侧脑室注射KA致海马损伤后.成年大鼠海马齿状回颗粒细胞异常增殖可能与Noggin表达波动有关.

Noggin participates in dentate gyrus subgranular zone granular cell proliferation following kainic acid-induced hippocampal injury in rats

Objective To investigate the relation between noggin expression changes and granular cell proliferation in the dentate gyrus subgranular zone (DG-SGZ) in rats with kainic acid (KA)-induced hippocampal injury. Methods Thirty-two adult male SD rats were randomly assigned into KA injury group (n=16) for intracerebroventricular KA injection and control group (n=16) which received intracerebroventricular normal saline injection (n=8) or no treatment (n=8). Nissl staining was used to assess the cell loss in the hippocampus, and in situ hybridization and immunofluorescence staining was used to detect noggin expression and BrdU-labeled cells in the DG-SGZ. Results The BrdU-labeled cells were found mainly in the DG-SGZ, and noggin mRNA-positive cells mainly in the hilus, DG-SGZ, CA3 and CAI area of the hippocampus. Seven days after KA treatment, substantial cell loss was found in the CA3 and CA4 areas, and the number of BrdU-labeled cells in the DG-SGZ markedly increased as compared with that in the saline group, especially on the same side of injection (P=0.006). The number of noggin mRNA-positive cells in the hippocampus significantly increased 3 days after KA injection, and began to decrease on day 7. Conclusion The granular cell proliferation in the DG-SGZ after KA-induced rat hippoeampal injury is probably associated with noggin expression changes in the hippoeampus.