Mansour H, Asher R, Dahl D, Labkovsky B, Perides G, Bignami A
Spinal Cord Injury Research Laboratory, Department of Veterans Affairs Medical Center, West Roxbury, MA 02132.
J Neurosci Res. 1990 Mar;25(3):300-11. doi: 10.1002/jnr.490250306.
Two distinct types of reactive astrocytes were studied in rat CNS. Reactive astrocytes secondary to penetrating trauma (anisomorphic gliosis) were induced by stab wounds to the brain. Reactive astrocytes secondary to Wallerian degeneration (isomorphic gliosis) were induced in spinal cord dorsal columns by dorsal rhizotomy proximal to dorsal root ganglia. Anisomorphic glial scars did not stain with antibodies to the glial hyaluronate-binding protein (GHAP), a structural glycoprotein of white matter extracellular matrix. Conversely, isomorphic glial scars were still GHAP-positive 3 months after dorsal root transection. Only after 5 months did GHAP immunoreactivity start to disappear from the isomorphic glial scar. Extensive dorsal rhizotomy was performed at the lumbar level to produce Wallerian degeneration of spinal cord dorsal columns. One month later, the rats were reoperated and two thoracic dorsal roots were implanted in the degenerated dorsal columns. The rats were examined 1 month after grafting. As expected, there was a dense anisomorphic glial scar at the site of surgery, while the dorsal columns above the graft showed isomorphic gliosis. Extensive axonal growth was observed in the dense glial scar surrounding the graft. Conversely, no axonal growth was observed in the degenerated dorsal columns undergoing isomorphic gliosis above the implant. The findings suggested that GHAP-negative astrocytes responding to traumatic injury are permissive for axonal growth and that GHAP-positive astrocytes responding to Wallerian degeneration are not permissive.
在大鼠中枢神经系统中研究了两种不同类型的反应性星形胶质细胞。穿透性创伤继发的反应性星形胶质细胞（异形性胶质增生）由脑部刺伤诱导产生。沃勒变性继发的反应性星形胶质细胞（同形性胶质增生）通过在背根神经节近端进行背根切断术在脊髓背柱中诱导产生。异形性胶质瘢痕不能被针对胶质透明质酸结合蛋白（GHAP）的抗体染色，GHAP是白质细胞外基质的一种结构糖蛋白。相反，在背根切断术后3个月，同形性胶质瘢痕仍然呈GHAP阳性。仅在5个月后，GHAP免疫反应性才开始从同形性胶质瘢痕中消失。在腰段进行广泛的背根切断术以产生脊髓背柱的沃勒变性。1个月后，对大鼠再次进行手术，并将两条胸段背根植入变性的背柱中。移植后1个月对大鼠进行检查。正如预期的那样，手术部位出现了致密的异形性胶质瘢痕，而移植上方的背柱显示出同形性胶质增生。在移植周围致密的胶质瘢痕中观察到广泛的轴突生长。相反，在植入物上方发生同形性胶质增生的变性背柱中未观察到轴突生长。这些发现表明，对创伤性损伤作出反应且GHAP阴性的星形胶质细胞对轴突生长具有促进作用，而对沃勒变性作出反应且GHAP阳性的星形胶质细胞则不具有促进作用。
