褪黑素对年龄相关的小鼠脑组织核转录因子和突触素活性的影响

摘要

目的 研究褪黑素(melatonin,MT)对不同年龄小鼠脑组织胶质纤维酸性蛋白(GFAP)和目的核转录因子(NF-kB)以及突触素(SYN)的表达,探讨MT与年龄相关的作用机理.方法 40只雄性B6C3F1小鼠分为4组,5.5个月(年轻组)20只,26个月(老年组)20只,年轻组和老龄组各10只为对照组,10只为MT处理组.动物每天喂以0.04 mg/kg的MT,2.5月后取小鼠脑组织,采用免疫组化染色法检测GFAP、NF-kBp65和SYN表达活性变化.结果 发现大脑中的NF-kB随着年龄的增长而增长,在MT处理的老年组小鼠大脑则呈现相反的趋势(P＜0.05).SYN的表达随着年龄的增长有所下降,MT处理的老年组小鼠大脑SYN的表达增强(P＜0.05).同时检测胶质细胞的GFAP表达随着年龄增长而提高,但在MT处理的老年组没有显著性差异(P＞0.05).结论 神经胶质酸性蛋白(GFAP)的表达在老年鼠几乎不受MT作用的影响,但MT降低了NF-kB p65的表达水平并提高SYN的活性,减缓大脑的老化过程,起到了保护大脑的作用.%Objective To study the effect of melatonin on the expressions of glial fibrillary acidic protein (GFAP), nuclear factor-κB (NF-κB p65) and synaptophysin in mice of different ages. Methods Twenty young male B6C3F1 mice (5.5 months) and 20 aged mice (26 months) were both divided into control and melatonin treatment (daily dose of 0.04 mg/kg) groups. After 2.5 months of treatment, the brain tissues of the mice were collected to examine the expressions of GFAP, NF-kB and SYN by immunohistochemistry. Results In the control groups, the expression of NF-kB p65 in the brain tissue increased with age, whereas a reverse change was found in melatonin-treated aged rats (P<0.05). Synaptophysin expression also decreased with age, but melatonin treatment significantly enhanced its expression in aged mice (P<0.05). GFAP expression in the brain tissue increased with age regardless of melatonin treatment (P>0.05). Conclusion GFAP expression is almost not affected by melatonin treatment in aged mice. Melatonin can reduce the expression levels of NF-kB p65 and synaptophysin in the brain tissue to protect the brain and slow down the aging process.