Effects On Expression Of C-fos With Spinal Cord Injury After Transplanting Microencapsulated Sciatic Nerve Tissue/cells Allograft

Objective: To study the recovery of function of injured spinal cord by xenotransplantation of Schwann cells,we observed the changes of c-fos after spinal cord injury and the changes after transplantation of microencapsulated sciatic nerve's tissue/cells by using immunohistochemistry method.Methods: Bilateral sciatic nerves of rabbits were dissected under sterile conditions and made into nerve's tissue/cells suspension. Following centrifugation, the tissue/cells were mixed with 1.5% sodium alginate solution. The mixture was then extruded using a droplet generation device into 20mmol/L barium chloride solution to form barium-alginate capsules. A total of 95 adult Sprague-Dawley rats were randomly divided into four groups: Group A,B,C and D. five rats of Group D were normal control. Thirty animals in each group of A, B and C were performed a lateral hemisection of spinal cord at right T10 level,then gelatin sponge alone, with nerve's tissue/cells suspension and with microencapsulated nerve's tissue/cells were implanted into the injured area respectively. 6h,12h,24h,3d,7d and 14d postinjury, 5 rats of each group in A, B and C as well as the normal rats were anesthetized and perfused transcardially with 4% paraformaldehyde. The two segments of caudal spinal cord of the injury level and the ipsilateral dorsal root ganglion were taken out. The spinal cord and the DRG of the normal rats at corresponding level were removed. Immunohistochemical staining and image analysis techniques were used to detect the changes of SP in the spinal dorsal horn and the DRG .Results:After hemisected SCI the number of the positive neurons the mean optical density were increase on the six hour.Gray matter c-Fos protein expression increases obviously. Anterior horn and posterior horn neuron has the expression. The masculine cell c-Fos protein dyes the yellowish brown color located at the cell nucleus, After hemisected SCI it was started to reduce on the 12th hour and then it was started to increase on the 24th hour.But still it was higher than the normal group(4.05±0.38).After hemisected SCI the masculine cell of reduces on the three day. Compared with normal group,there were no significant changes in spinal dorsal horn on the 1st week and 2st week(P <0.05).The c-fos expression in the A was definitely lower than in the C or in the B,the difference 6h,12h,24h,3d after operation is significant(P <0.05).The c-fos expression difference between the B and the C is significant(P <0.05).The diffence between all three groups was not significant 7d or 14d after operation(P> 0.05).Conclusion (1) The results indicate that allograft of micro-encapsulated SCs can increase the expression of c-fos spinal dorsal horn,and protect sensory neurons after SCI. (2) allograft of micro-encapsulated SCs can reduce secondary spinal cord injury by down-regulation of c-fos expression on some degree.