Objective To investigate the effects of chondroitinase ABC (ChABC) on axonal myelination and glial scar after spinal cord injury (SCI) in rats. Methods Seventy-two adult male Sprague Dawley rats were randomly assigned into ChABC treatment group (group A), saline treatment group (group B), and sham operation group (group C), 24 rats in each group. In groups A and B, the SCI model was established with modified Allen’s method and then the rats of groups A and B were administrated by subarachnoid injection of 6 μL ChABC (1 U/mL) and saline respectively at 1 hour after injury and every day for 1 week; the rats of group C served as control, which canal was opened without damage to spinal cord. At 1, 7, 14, and 28 days after operation, the locomotor functions were evaluated according to the Basso-Beattie-Bresnahan (BBB) score scale; and the spinal cord samples were harvested for HE staining, Nissl staining, and immunohistochemistry analysis to detect the change of myelin basic protein (MBP), growth associated protein 43 (GAP-43), and glial fibrillary acidic protein (GFAP) of the injured spinal cord. Results At different time points, the BBB score of group C was significantly higher than those of groups A and B (P lt; 0.05), and the BBB score of group A was significantly better than that of group B at 14 and 28 days after operation (P lt; 0.05). HE staining and Nissl staining showed that the morphous and the neuron number of the remainant injured spinal cord in group A were better than those in group B. The integral absorbance (IA) values of MBP and GAP-43 and the positive area of GFAP after SCI in groups A and B were significantly higher than those in group C at different time points (P lt; 0.05), and the IA values of MBP and GAP-43 were significantly higher in group A than those in group B at 7, 14, and 28 days after operation (P lt; 0.05), but the positive area of GFAP was significantly smaller in group A than that in group B (P lt; 0.05). Conclusion The ChABC can effectively improve the microenvironment of the injured spinal cord of rats, enhance the expressions of MBP and GAP-43, and inhibit the expression of GFAP, which promotes the axonal regeneration and myelination, attenuate glial scar formation, and promote the recovery of nerve function.
Objective To investigate the effect of chondroitinase ABC (ChABC) on the expression of growth associated protein 43 (GAP-43) and gl ial fibrillary acidic protein (GFAP) after spinal cord injury (SCI) in rats. Methods A total of 150 adult female SD rats, weighing 250-300 g, were randomly divided into ChABC treatment group (group A), sal ine treatment group (group B), and sham operation group (group C) with 50 rats in each group. In groups A and B, the rats were made the SCI models and were treated by subarachnoid injection of ChABC and sal ine; in group C, the rats were not treated as a control. At 1, 3, 7, 14, and 21 days after operation, the Basso, Beattie, and Bresnahan (BBB) score system was used toevaluate the motion function, and immunofluorescent histochemical staining was used to observe the expressions of GAP-43 and GFAP. Results At different time points, the BBB scores of groups A and B were significantly lower than those of group C (P lt; 0.05); there was no significant difference in BBB score between groups A and B after 1, 3, and 7 days of operation (P gt; 0.05), but the BBB score of group A was significantly higher than that of group B after 14 and 21 days of operation (P lt; 0.01). At different time points, the GAP-43 and GFAP positive neurons of groups A and B were significantly higher than those of group C (P lt; 0.05). After 14 and 21 days of operation, the GAP-43 positive neurons of group A were more than those of group B (P lt; 0.01). After 7, 14, and 21 days of operation, the GFAP positive neurons of group A were significantly less than those of group B (P lt; 0.01). Conclusion ChABC can degrade gl ial scar, improve the microenvironment of the injured region and enhance the expression of GAP-43, which promotes axonal growth and extension.
Objective To investigate the effect of chondroitinase ABC (ChABC) on the expression of growth associated protein 43 (GAP-43) and gl ial fibrillary acidic protein (GFAP) after spinal cord injury (SCI) in rats. Methods A total of 150 adult female SD rats, weighing 250-300 g, were randomly divided into ChABC treatment group (group A), sal ine treatment group (group B), and sham operation group (group C) with 50 rats in each group. In groups A and B, the rats were made the SCI models and were treated by subarachnoid injection of ChABC and sal ine; in group C, the rats were not treated as a control. At 1, 3, 7, 14, and 21 days after operation, the Basso, Beattie, and Bresnahan (BBB) score system was used toevaluate the motion function, and immunofluorescent histochemical staining was used to observe the expressions of GAP-43 and GFAP. Results At different time points, the BBB scores of groups A and B were significantly lower than those of group C (P lt; 0.05); there was no significant difference in BBB score between groups A and B after 1, 3, and 7 days of operation (P gt; 0.05), but the BBB score of group A was significantly higher than that of group B after 14 and 21 days of operation (P lt; 0.01). At different time points, the GAP-43 and GFAP positive neurons of groups A and B were significantly higher than those of group C (P lt; 0.05). After 14 and 21 days of operation, the GAP-43 positive neurons of group A were more than those of group B (P lt; 0.01). After 7, 14, and 21 days of operation, the GFAP positive neurons of group A were significantly less than those of group B (P lt; 0.01). Conclusion ChABC can degrade gl ial scar, improve the microenvironment of the injured region and enhance the expression of GAP-43, which promotes axonal growth and extension.
Objective To investigate the effects of Neuritin on the regeneration of the neural axons after acute spinal cord injury (SCI) in rats. Methods The model of acute SCI at T10 was establ ished in 54 adult healthy Wistar rats (half males and half females) weighing 250-300 g by using the improved Allen’s weight-drop method. The rats were randomly dividedinto 3 groups. 100 μL (6 μg) Neuritin and His protein was injected into group A (n=24) and group B (n=24), respectively,through subarachnoid catheter. Six rats from each group were killed 3, 7, 14, and 28 days after injury to receive Basso, Beattie and Bresnahan (BBB) locomotor rating scal ing, HE staining observation, and immunohistochemistry staining observation for neurofilament 200 (NF-200) and growth associated protein 43 (GAP-43). Group C (n=6) served as sham-operated group receiving laminectomy without spinal injury and with an empty catheter in the subarachnoid space and received the above observations 7 days after injury. Results BBB scale: after operation, the scale of groups A and B was increased over time; group A was significantly higher than group B from 14 days (P lt; 0.05); group C was higher than groups A and B at different time points after operation (P lt; 0.05). HE staining: in group C, the injured spinal tissue was normal after operation; from 7 days after operation, group A presented deeper-stained nissl body, less physal iferous cells, and more nerve synapses when compared with group B. NF-200 and GAP-43 immunohistochemistry observation: in group C, there was just l ittle positive expression; while in groups A and B, positive expression of NF-200 and GAP-43 was evident in the spinal cord from 7 days after operation. Mean density integral absorbency (IA) value of NF-200 and GAP-43: group A was higher than group B at each time point (P lt; 0.05) and group C was lower than groups A and B at each time point (P lt; 0.05). Conclusion Local application of exogenous Neuritin can promote the axonal regeneration after acute SCI in rats and the recovery of the locomotion function of hind-limbs in rats.
Objective To observe the effects of neural stem cells(NSCs) transplantation on the glial cell line-derived neurotrophic factor (GDNF) and growth associated protein 43(GAP-43) after the spinal cord injury(SCI), and to investigate the mechanism of repairing the SCI by NSCs transplantation. Methods The neural stem cells from the hippocampus of rats’ embryo were cultured and identified by immunocytochemistry. The SCI model was made by the modified Allen device. Sixty adult Wistar rats were randomly divided into three groups: spinal cord injury was treated with transplantation of NSCs (group A, n=24), with DMEM solution(group B, n=24) and normal control group without being injured(group C, n=12). Seven days after the operation of SCI, the NSCs were transplanted into the injured site. Then GAP-43 and GDNF expressions were tested by RT-PCR and immunohistochemistry. Results Compared with group B, the GDNF mRNA expression of group A increased by 23.3％ on the 1st day, by 26.8% on the 3rd day and by 32.7% on the 7th day; the GAP-43 mRNA expression increased by 19.5% on the 1st day, 21.6% on the 3rd day and 23.1% on the 7th day. There were statistically significant differences(Plt;0.05). Conclusion The transplantation of NSCs can change the microenvironment injured site and promote the regeneration of axon by enhancing the expressions of GDNF mRNA and GAP-43 mRNA. It is one of the mechanisms of repairing the SCI by NSCs transplantation.