大鼠脊髓损伤后脊髓组织中基质细胞衍生因子1α的时空分布

Temporal and spatial distributions of stromal cell-derived factor-1α(SDF-1α) in spinal cord tissue after spinal cord injury in rat

中文关键词:  脊髓损伤  基质细胞衍生因子1α  时空分布  大鼠

英文关键词:Spinal cord injury  Stromal cell-derived factor-1α  Temporal and spatial distributions  Rat

中文摘要:

  【摘要】 目的：观察Wistar大鼠脊髓损伤后脊髓组织中基质细胞衍生因子1α（SDF-1α）的表达及分布变化，探讨SDF-1α在脊髓损伤后脊髓中的时空分布特点。方法：取成年雌性Wistar大鼠90只，随机分成3组：正常组（n=10），假手术组（单纯椎板切除，n=10）和损伤组（n=70）。损伤组根据损伤后取材时间点不同分为1、2、3、4、7、14、28d组。损伤组按改良的Impactor model Ⅱ法，暴露T10脊髓节段，将10g条形重物从2.5cm高度垂直打击该段脊髓，制作脊髓损伤模型。按设定的时间点将大鼠在多聚甲醛灌注下取以T10为中心的2cm脊髓组织，取离损伤中心2mm和7mm处脊髓组织横断切片，使用HE及免疫组织化学法进行染色，观察并分析脊髓形态学变化和SDF-1α表达的时空分布特点。结果：正常组和假手术组的脊髓形态结构完整，损伤组中灰质神经元数量减少，白质纤维结构紊乱。免疫组化染色正常组和假手术组的脊髓中均匀分布少量SDF-1α，损伤组脊髓损伤中心近端（2mm）和远端（7mm）SDF-1α表达量都明显上升，损伤近端的SDF-1α阳性细胞数量增幅远多于远端；脊髓灰质中阳性细胞明显多于白质（P<0.05）。在大鼠脊髓损伤后1d脊髓组织中的SDF-1α阳性细胞数量开始上升，到损伤后2d时脊髓灰质中SDF-1α阳性细胞达到高峰，之后逐渐下降，损伤后7d时损伤近端SDF-1α阳性细胞数量高于正常组和假手术组（P<0.05），远端与正常组和假手术组无统计学差异（P>0.05）；到损伤后14d和28d时近端和远端与正常组和假手术组均无统计学差异（P>0.05）。结论：SDF-1α在Wistar大鼠脊髓损伤后脊髓组织中表达活跃，呈现出明显的时空分布特点。

英文摘要:

  【Abstract】 Objectives: To observe and investigate the temporal and spatial distributions of stromal cell-derived factor-1α (SDF-1α) in spinal cord after spinal cord injury(SCI) in Wistar rat. Methods: Adult female Wistar rats(n=90) were randomly divided into three groups: normal group(n=10), sham group(simple vertebra excision, n=10) and injured group(n=70). Based on the duration after spinal cord injury, the injured group was divided as 1d, 2d, 3d, 4d, 7d, 14d, 28d. According to the improved Impactor model Ⅱ, the T10 SCI model was introduced by 10g weight bar falling from 2.5cm height. With the perfusion of paraformaldehyde, 2cm spinal tissue(including T10) was taken. The cross sections of 2mm and 7mm adjacent to the injury site were used. Immunohistochemical and hematoxylin-eosin staining were used to detect morphology of spinal cord and the temporal and spatial distributions of SDF-1α in spinal cord in each group. Results: In normal and sham group, the structure of spinal cord was integrated. In injuried group, the neurons in the gray matter decreased and the fiber in the white matter was in disorder. In normal and sham group, little SDF-1α was well-distributed in the spinal cord. After the spinal cord injury in rat, quantity of SDF-1α obviously increased. The site 2mm adjacent(proximal) to the injury showed greater responses than the area of 7mm away(distal), with the gray matter containing more SDF-1α positive nerve cells than the white matter. SDF-1α positive nerve cells in the gray matter increased at 1d after injury and reached a peak at 2d after injury, then decreased gradually. At 7d, the proximal region still had more SDF-1α positive nerve cells than normal group, but distal region returned to normal level. There was no obvious difference between sham group and injured group at 14d and 28d after injury. Conclusions: SDF-1α is widely expressed in the spinal cord and presented temporal and spatial distributions following spinal cord injury in rat.