中文摘要：

目的：探讨沉默调节蛋白1（Sirt1）对神经元轴突生长的影响。方法体外原代分离培养胚胎海马神经元，观察Sirt1在72 h神经元的分布表达；通过RNAi技术下调Sirt1基因，观察其对72 h神经元轴突长度的影响；通过质粒转染过表达Sirt1基因或药物白藜芦醇（RES）激活Sirt1蛋白，检测其对72 h神经元轴突长度的影响。结果免疫荧光染色结果显示Sirt1位于海马神经元的生长圆锥以及胞体和突起，尤其是轴突末端；与正常对照组（Sirt1正常表达组）相比，Sirt1表达下调可显著缩短72 h海马神经元轴突的长度[由（178.3±3.2）μm缩短到（110.2±18.30）μm，P＜0.01]；与正常对照组（Sirt1正常表达组）相比，基因过表达Sirt1可显著增加72 h海马神经元轴突的长度[由（178.3±3.2）μm增长到（310.6±39.5）μm，P＜0.01]。与药物对照组（DMSO处理组）相比，药物RES激活Sirt1蛋白亦可显著增加72 h海马神经元轴突的长度[由（292.8±11.2）μm增长到（525.1±49.7）μm，P ＜0.01]。结论Sirt1在神经元的轴突生长中起着重要的作用，可作为轴突再生一个潜在的治疗靶点。

英文摘要：

Objective To investigate the effect of silence regulatory protein 1 （Sirt1） on axonal outgrowth. Methods The hippocampal neurons was first isolated in vitro from rat embryos. The distribution and expression of Sirt1 were then detected 72 h later. The down-regulation of Sirt1 was induced by RNAi technology and up-regulation of Sirt1 was in-duced by overexpression of Sirt1 and resveratrol （RES）. Immunofluorescence staining was used to examine the axon length. Results Immunofluorescence staining showed that Sirt 1 was located in neuronal cell body and neurite, especially in the distal axons. Down-regulation of Sirt1 significantly decreased axonal length compared with siRNA control group [（178.3 ± 3.2） μm vs. （110.2 ± 18.30） μm, P〈0.01 ]; Overexpression of Sirt1 significantly increased axonal length com-pared with eGFP control group [（178.3±3.2）μm vs （310.6±39.5）μm, P〈0.01 ];Activation of Sirt1 by RES treatment al-so significantly increased axonal length compared with vehicle control group （DMSO treated group） [（291.7±13.2）μm vs. （525.1±49.1）μm, P〈0.01 ]. Conclusions Sirt1 plays a key role in axonal growth which may be used as a potential thera-peutic target of axon regeneration.