脊髓损伤后星形胶质细胞增生动态变化分析

目的:分析脊髓损伤(SCI)后星形胶质细胞(Ast)增生动态变化。方法:建立Ast划痕损伤模型及大鼠SCI模型,在多个时间点(0、6、12、24、48、72 h)观察Ast划痕损伤后细胞形态、增殖及迁徙的变化,并设立对照组应用ELISA法检测划痕损伤后各个时间点Ast分泌致炎因子TNF-α、IL-1β、IL-6表达量;应用免疫荧光染色及Western blot分析不同时间点(0、1、3、7、14、28 d)大鼠SCI后GFAP的表达量变化。结果:划痕损伤后12 h划痕边缘已出现部分细胞增生及增殖细胞(Brdu染色阳性细胞),损伤后24 h细胞已明显增生并大量增殖,损伤后48 h细胞体普遍增大,突起明显增多,同时有大量细胞已迁徙至划痕中央处,损伤后72 h增生的细胞及迁徙至划痕的细胞几乎已覆盖划痕,部分形成瘢痕;与对照组比较,损伤后12 h TNF-α、IL-1β、IL-6均明显增加(P<0.05),24、48及72 h TNF-α、IL-1β、IL-6表达量增加更加明显(P<0.01)。大鼠SCI模型显示SCI后1 d GFAP表达量增加不明显,3 d后明显增加,而且一直呈增加趋势,14²8 d后形成表达高峰。结论:Ast活化增生是SCI后一个持续且普遍的标志性病理生理过程。

The Pattern of Astrogliosis after Spinal Cord Injury

Objective:To investigate the astrogliosis dynamic changes after spinal cord injury(SCI).Methods:The Astrocyte scratch wound model in vitro and rats SCI model was established.The changes of astrocyte morphology,proliferation and migration were observed at a series of time points(0,6,12,24,48,72 h) in astrocytic scratch wound model while the expression of pro-inflammatory cytokines TNF-α,IL-1βand IL-6 were investigated by ELISA method.The immunofluorescence staining and western blot methods were used to evaluate the expression of GFAP in rats after SCI.Results:At 12 h after scratch wound,hypertrophic astrocyte and proliferative astrocytes emerged at the scratch wound edge.Astrocyte became obviously hypertrophic and massively proliferated at 24 h.The soma became generally hypertrophic and the neurites obviously increased.A large number of astrocytes migrated to the epicenter of scratch wound at 48 h and proliferative and migratory astrocytes almost overlapped scratch wound and partly formed glial scar at 72 h.Meanwhile,the expressions of TNF-α,IL-1βand IL-6 were significant increased at 12 h(P<0.05)which continued to increase at 24 h,48 h and 72 h after scratch wound compared to control group(P<0.01).The expression of GFAP did not obviously increased at 1d after SCI,which began to increase after day 3 and reached the peak at 14 to 28 d after SCI.Conclusion:Astrocytosis is a continuous and general hallmark of pathophysiological process after SCI.