大鼠脊神经前根切断后脊髓内Slit1表达的变化

Changes of Slit1 expression in spinal cord after the section of dorsal root in rats

中文关键词:  脊神经前根切断  脊髓  Slit1

英文关键词:Dorsal root transection  Spinal cord  Slit1

中文摘要:

  【摘要】 目的：探讨脊神经前根损伤后，大鼠脊髓组织中Slit1的表达变化，为进一步研究Slit1在神经再生中的作用提供依据。方法：应用2月龄SD大鼠共100只，体重250±20g，其中80只SD大鼠实施左侧L5及L6脊神经前根切断，分别在伤后1d、3d、7d、14d时处死（每个时间点20只），取L5~L6脊髓节段，标记左右；左侧半L5~L6脊髓节段为实验组；右侧半为自身对照组。假手术大鼠（20只）实施麻醉及暴露L5及L6脊神经手术，未行L5及L6脊神经前根切断术，取其L5~L6脊髓节段为空白对照组。采用免疫组化、Western blotting及RT-PCR法检测大鼠脊髓组织中Slit1的变化。结果：脊神经前根切断后1d、3d、7d、14d，实验组中Slit1阳性细胞数分别为5.78±1.53、15.85±2.65、23.93±1.53、8.78±1.78；自身对照组中分别为2.31±1.63、2.57±1.89、3.20±2.16、3.02±2.15。各时间点实验组中Slit1阳性细胞数显著高于空白对照组（2.89±1.26）及自身对照组（P＜0.05）。Western blotting示脊神经前根切断后1d、3d、7d、14d，实验组Slit1相对表达量分别为0.326±0.09、0.448±0.05、0.638±0.07、0.304±0.07；自身对照组分别为0.038±0.02、0.038±0.01、0.035±0.02、0.046±0.03。各时间点实验组Slit1相对表达量与空白对照组（0.038±0.03）及自身对照组比较，差异有显著性（P＜0.05）。RT-PCR示脊神经前根切断后1d、3d、7d、14d，实验组Slit1 mRNA相对量分别为0.380±0.03、0.425±0.04、0.768±0.05、0.605±0.04；自身对照组分别为0.210±0.04、0.265±0.03、0.292±0.02、0.261±0.02。各时间点实验组Slit1 mRNA相对量与空白对照组（0.231±0.03）及自身对照组比较，差异有显著性（P＜0.05）。结论：脊神经前根切断后，同侧脊髓灰质前角内Slit1的表达显著增加。

英文摘要:

  【Abstract】 Objectives: To investigate the changes of Slit1 expression in spinal cord after the section of dorsal root in rats, and to provide evidence for the role of Slit1 in nerve regeneration． Methods: The left dorsal roots of L5 and L6 spinal nerve were transected from 80 2-month-old Sprague-Dawley rats, and the changes of Slit1 expression were detected with RT-PCR, Western blotting and immunohistochemical methods in the related spinal cord at 1d, 3d, 7d and 14d, respectively． The left halves of these L5/6 spinal cords were included in test group, the right halves of these L5/6 spinal cords were included in self-control group and the L5/6 spinal cords from sham operation rats(which were anaesthetized and the L5 and L6 spinal nerves were exposed, but without section operation, n=20) in blank control group. Then the number of Slit1 positive cells and the average integral optical density value(AIODV) were determined with image analysis． Results: The numbers of Slit1 positive cells in test group at 1d, 3d, 7d and 14d were 5.78±1.53, 15.85±2.65, 23.93±1.53 and 8.78±1.78; the numbers in self-control group were 2.31±1.63, 2.57±1.89, 3.20±2.16 and 3.02±2.15, respectively． The number of Slit1 positive cells in test group was significantly higher than that in blank control groups(2.89±1.26) or that in self-control group(P＜0.05). Western blotting showed the relative expressions of Slit1 in test group at 1d, 3d, 7d and 14d were 0.326±0.09, 0.448±0.05, 0.638±0.07 and 0.304±0.07; the numbers in self-control group were 0.038±0.02, 0.038±0.01, 0.035±0.02 and 0.046±0.03 respectively. Compared with blank control group(0.038±0.03) and self-control group, the relative expression of Slit1 in test group were significant(P＜0.05). RT-PCR showed the relative expressions of Slit1 mRNA in test group at 1d, 3d, 7d and 14d were 0.380±0.03, 0.425±0.04, 0.768±0.05 and 0.605±0.04; the numbers in self-control group were 0.210±0.04, 0.265±0.03, 0.292±0.02 and 0.261±0.02 respectively. Compared with blank control group(0.231±0.03) and self-control group, the relative expression of Slit1 mRNA in test group was significantly higher(P＜0.05). Conclusions: After the section of dorsal root, Slit1 expression in spinal cord is significantly up-regulated.