微囊化兔坐骨神经组织细胞移植对大鼠损伤脊髓后IκBα表达的影响及意义

目的探讨微囊化兔坐骨神经组织细胞移植于大鼠损伤脊髓后对其IκBα的表达及活性的影响。方法家兔10只用于制备兔坐骨神经组织的胞悬液。成年SD大鼠120只随机分为4组：微囊组（微囊化兔坐骨神经组织细胞移植组，n=36）、细胞组（坐骨神经组织细胞移植组，71—36）、单损组（单纯损伤组，n=36）、假手术组（n=12）。微囊组、细胞组和单损组大鼠在脊髓半横断伤后，立即于损伤处分别植入明胶海绵吸附的10uL微囊化坐骨神经组织细胞、明胶海绵吸附的10uL坐骨神经组织细胞以及明胶海绵吸附的10uL生理盐水。分别于术后6h、12h、24h、3d、7d、14d（每个时相取6只大鼠）取出损伤部位脊髓标本，假手术组（每个时相取2只大鼠）则取相应节段脊髓。石蜡包埋后切片，行免疫组织化学染色观IκBα的表达变化。结果IκBα阳性细胞主要见于神经元细胞及胶质细胞的胞浆内。大鼠脊髓损伤后上述细胞IκBα表达降低，24h降到最低点．3d后表达开始回升，7d逐步恢复正常水平。微囊组与单损组、细胞组比较差异有显著性（P〈0．05）。结论微囊化兔坐骨神经组织细胞移植于大鼠损伤脊髓后，可以通过抑制IκBα磷酸化降解环节，从而抑制炎症反应。

Expression of Transplantation of Microencapsulated Rabbit Sciatic Nerve on the Expression of IκBα after Spinal Cord Injury in Rats

Objective To investigate the effects of transplantation of microencapsulated rabbit sciatic nerve tissue/cells on IκBα activity and expression after spinal cord injury（SCI） in rats. Methods The rabbit sciatic nerve tissue/cells suspension was prepared from ten rabbits. SCI was conducted by hemisection injury of spinal cord. A total of 120 adult Sprague Dawley rats were randomly divided into four groups：36 rats in microencapsulated group （10uL microencapsulated sciatic nerve tissue/cells suspension absorbed in gelatin sponge was transplanted into the SCI site immediately after SCI）, 36 rats in cellular group （10uL sciatic nerve tissue/cells suspension absorbed in gelatin sponge was transplanted into the SCI site immediately after SCI）, 36 rats in injury control group （10uL physiological saline absorbed in gelatin sponge was administered to the SCI site immediately after SCI）, 12 rats in sham-injury controll group （spinal cord was neither injured nor transplanted, with vertebrae removed only）. For microeneapsulated group, cellular group, and injury control group, spinal cord samples were taken out from 6 rats in each group respectively 6 h,12 h,24 h,3 d,7 d,and 14 d after SCI, while corresponding samples were collected from 2 rats in sham-injury group each time. All samples were postfixed and embedded in paraffin and then sectioned, followed by undergoing immunohistochemical stain for detection of IκBα. Re sults The IκBα protein are mainly seen in the cytoplasm of neurons and gliocytes. The expression of IκBα decreased and reached the lowest level 24 hours after SCI, and began to rise 3 d after, and gradually returned to normal level 7 d after. The expression level of IκBα in microcapsulated group was significantly different from those in injury control group and cellular group （P〈0.05）. Conclusion It suggests that the transplantation of microencapsulated rabbit sciatic nerve tissue/cells could inhibit the phosphorylation of IκBα, thus accordingly suppress inflammatory re