大鼠脊髓损伤后GFAP、cPLA2的表达变化及相关性研究

Expression and relationship of GFAP and cPLA2 in spinal cord injury

目的研究大鼠脊髓半横断损伤后胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和胞浆型磷脂酶A2(cytosolic phospholipase A2,cPLA2)的表达与分布,并分析其相关性,探讨两者在脊髓损伤后表达的意义和可能的内在关系。方法 30只SD大鼠随机分为脊髓损伤组(1、3、7、14和21 d)与假手术组,脊髓损伤组用T10节段半横断法(右侧)造模,而假手术组只行椎板切除不损伤脊髓。在各时间点取材后用尼氏染色观察脊髓组织病理学改变,采用免疫组织化学法检测脊髓组织GFAP与cPLA2表达,并经Motic Images Advanced软件处理后进行Pearson相关性分析。结果尼氏染色示脊髓损伤后神经元坏死,肿胀,空泡形成,形态不完整。免疫组织化学法示脊髓损伤后可见GFAP与cPLA2表达均增高,其中GFAP在各时间点表达逐渐增多,cPLA2表达在损伤后14 d达到高峰,GFAP与cPLA2阳性产物面积相关性分析提示其相关系数为0.74,差异无统计学意义(P=0.15),两者平均光密度值行相关分析后,相关系数为0.90,具有统计学意义(P=0.04)。结论大鼠脊髓损伤后GFAP与cPLA2表达均增多,且两者在损伤过程中表达具有相关性。

[Objective] To investigate the expression and distribution of GFAP and cPLA2 in spinal cord hemisection injury. [Methods] 30 adult SD rats are randomly divided into two groups, sham group （n =5）, spinal cord injury group （n =25）. Animal model is made by spinal cord hemisection in the TI0 segment. The sham group just gets laminectomy without injury the spinal cord. The neural tissues are evaluated in pathology and imInunohistochemistry at lst/d, 3rd/d, 7th/d, 14th/d, 21st/d after the procedures. All the pictures are processed by Motic Images Advanced and analyzed by Pearson test. [Results] Nissl staining shows neuron necrosis, swelling and bubbles, without integrated neural structure in spinal cord injury, cPLA2 and GFAP expression are increased after injury, and GFAP increases gradually. The expression of cPLA2 reaches its peak at 21 d. The cPLA2 is significantly correlated with GFAP under Pearson correlation analysis （r=0.90, P =0.04） in mean optical density. [Conclusion] The expression of cPLA2 and GFAP are increased after spinal cord injury, and they may be related during injury.