神经生长因子在肺炎链球菌脑膜炎进程中的表达变化

Expression of nerve growth factor in progression of Streptococcus pneumoniae meningitis

目的观察神经生长因子在肺炎链球菌脑膜炎进程中的表达变化,以探讨神经生长因子在病程中的作用。方法将36只3周龄健康SD大鼠,雌雄均等随机分成对照组和模型组,对照组16只,模型组20只;模型组动物复制肺炎链球菌脑膜炎模型,对照组用生理盐水取代肺炎链球菌菌液,分别在建立模型24h和第5天时取大鼠脑脊液和脑组织,用酶联免疫吸附测定方法测定其中神经生长因子的蛋白含量和用荧光实时定量的方法测定神经生长因子mRNA相对含量。结果模型组建立模型24h后大鼠脑组织经生长因子mRNA为25.93±5.26,对照组为1.05±0.92;蛋白含量模型组为(48.9±3.5)pg/ml,对照组为(10.6±1.2)pg/ml;脑脊液中神经生长因子mRNA模型组为21.93±5.26,对照组1.12±0.92;蛋白含量模型组为(25.3±2.7)pg/ml,对照组为(6.3±1.3)pg/ml,两组比较差异有统计学意义(P<0.05);模型组建立模型第5天时大鼠脑组织经生长因子mRNA为10.76±4.35、蛋白含量为(26.5±2.3)pg/ml,对照组分别为mRNA13.57±5.12、蛋白含量为(13.8±2.1)pg/ml,模型组均明显高于对照组,差异有统计学意义(P<0.05);建立模型第5天与24h相比,大鼠脑组织和脑脊液中神经生长因子mRNA和蛋白含量也降低,差异有统计学意义(P<0.05)。结论神经生长因子在肺炎链球菌脑膜炎病理过程中上调的变化,为肺炎链球菌脑膜炎的治疗提供了新思路。

OBJECTIVE To observe the change of expression of nerve growth factor （NGF） in the process of Strep- tococcus pneumoniae meningitis so as to explore the effect of nerve growth factor on the illness course. METHODS Totally 36 healthy SD rats with 3 weeks of age were randomly divided into the control group and the model group with equal amount of male and female rats; 16 rats were classified as the control group, 20 rats as the model group, The rats in the model group were infected with S. pneunorniae, while the rates in the control group were injected with normal saline instead. The cerebrospinal fluid and brain tissues of the rats were sampled respectively at the time of 24 hours and the fifth day after the establishment of model. The protein content of the nerve growth factor was measured with the use of enzyme-linked immunosorbent assay, and the relative mRNA content of the nerve growth factor was determined by the real-time quantitative fluorescence. RESULTS After the building of model for 24 hours, the level of nerve growth factor mRNA in the brain tissues was 25. 93±5.26, 1.05 ±0.92 in the control group ; the protein content was （48.9 ± 3.5） pg/ml in the model group, （10.6±1.2） pg/ml in the control group. The level of nerve growth factor mRNA in the cerebrospinal fluid was 21.93-＋-5.26 in the model group, 1.12 ~0.92 in the control group; the protein content was （25.3!2.7）pg/ml in the model group, （6.3 ~1.3） pg/ml in the control group, the difference between the two groups was significant （P〈0.05）. On the fifth day of the model building, the level of nerve growth factor mRNA in the brain tissues was 10.76±4.35, 13.57 5.12 in the control group; the protein content was（26.54-2.3）pg/ml in the model group, （la. 8＋2.1）pg/ml in the control group, with the model group significantly higher than the control group, the difference was significant （P（0.05）. As compared with the model building on the fifth day and 24 hours, the nerve growth factor mRNA level and protein content in the brain tissues and the cerebral spinal fluid were decreased as well, the difference was significant （P〈0.05）. CONCLUSION The elevated level of nerve growth factor in the pathological process of S. pneurnoniae meningitis opens up a new idea for the clinical treatment.