大鼠脊髓损伤后胶质细胞生长因子的mRNA表达变化

Expression of glial growth factor mRNA after spinal cord injury in rats

目的:探讨胶质细胞生长因子(glialgrowthfactor,GGF)在大鼠脊髓损伤后的表达变化及意义。方法:采用改良Allen′s脊髓损伤打击模型,用逆转录聚合酶链式反应法(RT-PCR)检测胚胎大鼠脊髓内、正常成年大鼠脊髓内以及脊髓损伤后不同时间点伤段脊髓组织中GGF的mRNA表达。结果:GGF在成年大鼠正常脊髓内低水平表达,在胚胎脊髓中高水平表达。大鼠脊髓损伤后GGF的mRNA表达持续降低,在脊髓损伤后5d达到最低峰,之后GGF的mRNA表达可逐渐恢复。结论:GGF在脊髓生长发育中起重要作用;大鼠脊髓损伤后GGF的表达降低可能与脊髓损伤后少突胶质细胞大量死亡或凋亡有关,与脊髓损伤后轴突无法再生、脱髓鞘的髓鞘再生困难有关。

Objective：To study the expression of glial growth factor（GGF） mRNA in spinal cord after spinal cord injury. （SCI） in rats.Method：The contusion model of SCI resulting incomplete paraplegia in rats was established according to the method of modified Allen＇s.The expression of mRNAs encoding the GGF in the rat spinal cord after SCl,as well as in the spinal cord of normal rat and E16 and El8 embryos was measured through reverse transeription polymerase chain reaction （RT-PCR）.Resuit：The expression level of GGF mRNA was low in adult rats while significantly higher in El6 and El8 embryos（P〈0.01 ）.The expression level of GGF mRNA appeared to decrease during the first 5 days after SCI,thereafter it appeared to recover in the next two weeks.Conclusion：High level expression of GGF in embryos spinal cord of rats indicates that GGF may play an important role in the progression of spinal cord.The early reduction of GGF expression in the injury, site of spinal cord after SCI may be related to the widely necrosis or apoptosis of oligodendroeyte, and thus result in the difficulty of axon regeneration and remyelination in the spinal cord after SCI.