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

English Keywords:Spinal cord injury  Stromal cell-derived factor-1α  Temporal and spatial distributions  Rat

English Abstract:

  【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.