端粒酶在大鼠脊髓胶质瘢痕中表达及其与瘢痕形成的关系

Expression of telomerase in glial scar of rats with spinal cord injury and the relationship with the formation of glial scar

目的探讨端粒酶在大鼠脊髓胶质瘢痕中的表达及其与脊髓胶质瘢痕形成和发展的关系。方法 SD大鼠80只随机分为观察组和对照组各40只,观察组为脊髓损伤组,采用改良Allens重物坠落法造模;对照组为假手术组,仅打开椎板,暴露脊髓,不造成脊髓损伤。分别于术后1,3,5,7,14,28,42,56d取标本,用PCR-ELISA端粒酶检测法检测端粒酶表达,ELISA法检测胶质酸性纤维蛋白的表达,采用组织病理学观察胶质瘢痕的形成和发展。结果术后各时间点观察组端粒酶及胶质酸性纤维蛋白表达水平明显高于对照组(P<0.01);组织病理检测结果显示,观察组各时间点胶质瘢痕较对照组严重;观察组胶质瘢痕中胶质酸性纤维蛋白的表达与端粒酶表达变化呈正相关(r=0.755,P<0.01)。结论端粒酶在脊髓胶质瘢痕中呈动态表达,可能是促进胶质瘢痕形成的重要因素。

Objective To detect the expression of telomerase in glial scar and its correlation with the formation and development of glial scar in rats with spinal cord injury. Methods Eighty SD rats were randomly divided into experimental group and control group （sham group）. Spinal cord injury was induced by a modified impinger of Allen＇s impacting in the experimental group. In control group （sham group）, the vertebral plate was openned to expose the spinal cord without injuring the spinal cord. The telomerase expression was detected with PCR-ELISA by day 1, 3, 5, 7, 14, 28, 42 and 56 after injury. The glial scar formation and development was observed with the pathologic technique and the expression of glial fibrillary acidic protein （GFAP） in glial scar was detected with ELISA. Results The expression levels of telomerase and GFAP were significantly higher in experimental group than those in control group by all time points after spinal cord injury （P〈0.01）. The pathological examination showed that glial scar was severer in experimental group than that in control group. The expression of GFAP was positively correlated with the expression of telomerase （r= 0. 755, P〈0.01）. Conclusion Telomerase is in a dynamic expression in glial scar and may be an important factor for promoting the formation of glial scar.