大鼠脊髓损伤后星形胶质细胞特异性表达Gc的研究

ASTROCYTE IN CNS OF RAT CAN EXPRESS Gc AFTER SPINAL CORD INJURY

用免疫组织化学方法观察了脊髓的星形胶质细胞在损伤后出现的抗原性改变并对其改变的意义进行了探讨。实验选用Wistar大鼠 2 0只。实验组 10只 ,对脊髓 T1 0 节段进行完全横断 ;对照组 10只 ,只进行 T1 0 椎板切除术 ,不损伤脊髓。在术后第 1、3、5、7、14 d分别对 2 0只大鼠灌流固定 ,并取出 3 cm长手术段脊髓。用 anti-Galactocerebrosides( anti-Gc)和 anti-glial fibrillaryacidic protein( anti-GFAP)抗体对脊髓进行标记。结果表明 :脊髓损伤后第 7d,增生肥大的星形胶质细胞可以同时被 anti-GF AP和 anti-Gc标记 (荧光双标 )。此抗原表型改变至术后 14 d依然显现。被双标的星形胶质细胞在形态上与成熟的正常胶质细胞基本相同 ,而少突胶质细胞只为 anti-Gc单独标记。对照组脊髓星形胶质细胞和少突胶质细胞只为 anti-GFAP、anti-Gc分别标记。本实验结果提示 :大鼠脊髓受损后 ,星形胶质细胞出现 GFAP和 Gc二种抗原表型。此结果首次表明成熟哺乳动物脊髓损伤后星形胶质细胞也可出现类似少突胶质细胞特异性抗原抗体改变。这可能是星形胶质细胞对脊髓创伤的一种特异性反应。

By using immunohistochemistry method, we observed the change of the antigen in astrocytes after transection of rat spinal cord and evaluated the significance of such a change. Spinal cord samples from rats of 1, 3, 5, 7 or 14 days after the rat T 10 spinal cord was transected and samples from control animals(normal rats) were used for immunohistochemistry reaction with anti Gc and anti GFAP antibodies respectively/together. The astrocytes demonstrated both Gc like immunoreactivity (Gc LI) and GFAP like immunoreactivity (GFPA LI) 7 days after the injury, which lasted till 14 days after the injury. While oligodendrocytes demonstrated only Gc LI. Samples from normal rats demonstrated GFAP LI or Gc LI for astrocytes or oligodendrocytes respectively. After spinal cord injury, the astrocytes demonstrated both GFAP LI and Gc LI. The present study suggests that the astrocytes within the spinal cord of adult mammalian animals can express some antigen that is specific for oligodendriocytes after spinal cord injury. This change may be possibly a specific reaction to spinal cord injury. Thus, our result can offer some clue for elucidating the role of local microenvironment in the restoration of spinal cord from injury.