Objective To investigate the synergetic effect and possibil ity of repairing spinal cord injury (SCI) by transplantation of olfactory ensheathing cells (OECs) and chondroitinase ABC (ChABC) in adult rats. Methods Three adult male SD rats were used to isolated olfactory bulb and primarily cultured OECs. In the 8th or 9th day, OECs were transplanted, the concentration of cells was modulated to 1 × 105/μL. Fifty-four SD rats were made the models of T8 spinal cord crush injury and divided into 4 groups. In group A (control, n=36), injured site was not treated; in groups B, C and D (n=6), OECs, ChABC and OECs+ChABC were injected into injured site, respectively. At 1, 2, 3, 7 and 14 days after injury, the BBB score system was used to evaluate the motion function. At 0, 1, 2, 3, 7, 14 days in group A and at 14 days in groups B, C, D after injury, the maximal transverse diameter and gross area of necrosis were evaluated on HE stained sections. The immunofluorescence double label ing staining for gl ial-fibrillary acidic protein (GFAP)/CS56, GFAP/growth associated protein 43(GAP-43) and GFAP/neurofilament 160(NF160) was carried out to evaluate the regeneration of nerve fiber. Results At 14 days after injury, there were significant difference in the BBB scores between group A and groups B, C, D (P lt; 0.05), and between groups B, C and group D (P lt; 0.05), HE staining showed that the formation of cavity was observed in each group at 14 days after injury. There were significant difference in the maximal transverse diameter and gross area of necrosis between groups B, C, D and group A (P lt; 0.01), and between groups B, C and group D (P lt; 0.01). The immunofluorescence staining indicated that expression of GFAP were more intense in group A than in other groups, and the cavity of the lesion site was apparent, but it was moderate in groups B and C. The expression of GAP-43 was more intense in group D than in groups B and C. The expression of NF160 was more intense in group D. Conclusion Transplantation strategy of OECs combined with ChABC was effective in the repair of SCI in some extent.
Objective To investigate the division, prol iferation and differentiation abil ities of nestin+/GFAP+cell after spinal cord injury and to identify whether it has the characteristic of neural stem cells (NSCs). Methods Twelvemale SD rats, aged 8 weeks and weighing 200-250 g, were randomized into 2 groups (n=6 per group): model group inwhich the spinal cord injury model was establ ished by aneurysm cl ip compression method, and control group in which no processing was conducted. At 5 days after model ing, T8 spinal cord segment of rats in each group were obtained and the gray and the white substance of spinal cord outside the ependymal region around central tube were isolated to prepare single cellsuspension. Serum-free NSCs culture medium was adopted to culture and serum NSCs culture medium was appl ied to induce differentiation. Immunohistochemistry detection and flow cytometry were appl ied to observe and analyze the type of cells and their capabil ity of division, prol iferation and differentiation. Results At 3-7 days after injury, the model group witnessed a plenty of nestin+/GFAP+ cells in the single cell suspension, while the control group witnessed few. Cell count of the model and the control group was 5.15 ± 0.71 and 1.12 ± 0.38, respectively, indicating there was a significant difference between two groups (P lt; 0.01). Concerning cell cycle, the proportion of S-phase cell and prol iferation index of the model group (15.49% ± 3.04%, 15.88% ± 2.56%) were obviously higher than those of the control group (5.84% ± 0.28%, 6.47% ± 0.61%), indicating there were significant differences between two groups (P lt; 0.01). In the model group, primary cells gradually formed threedimensional cell clone spheres, which were small in size, smooth in margin, protruding in center and positive for nestin immunofluorescence staining, and large amounts of cell clone spheres were harvested after multi ple passages. While in the control group, no obvious cell clone spheres was observed in the primary and passage culture of single cell suspension. At 5 days after induced differentiation of cloned spheres in the model group, immunofluorescence staining showed there were a number of galactocerebroside (GaLC) -nestin+ cells; at 5-7 days, there were abundance of β-tubul in III-nestin+ and GFAP-nestin+ cells; and at 5-14 days, GaLC+ ol igodendrocyte, β-tubul in II+ neuron and GalC+ cell body and protruding were observed. Conclusion Nestin+/GFAP+ cells obtained by isolating the gray and the white substance of spinal cord outside the ependymal region around central tube after compressive spinal cord injury in adult rat has the abil ity of self-renewal and the potential of multi-polarization and may be a renewable source of NSCs in the central nervous system.