Yang H Y, Lieska N, Kriho V, Wu C M, Pappas G D
Department of Anatomy, University of Illinois at Chicago 60612, USA.
Exp Neurol. 1997 Jul;146(1):199-205. doi: 10.1006/exnr.1997.6518.
We have identified an early-appearing intermediate filament-associated protein (IFAP-70/280 kDa) in radial glia and their immediate derivatives. This IFAP is absent in the adult CNS. In this study, we examined the reexpression of this early glial differentiation trait in rat reactive astrocytes induced by stab injury of the cerebrum. Double-label immunofluorescence microscopy demonstrated that by 36 h postlesion, IFAP-70/280 kDa was present in a few GFAP-positive astrocytes in the area adjacent to the wound. As the gliotic reaction progressed, the number of IFAP-positive reactive astrocytes increased and by 5-6 days postlesion, IFAP-70/280 kDa was present in most of the hypertrophied astrocytes in tissue immediately adjacent to the wound. By 8 days postlesion, while the number of IFAP-negative reactive astrocytes away from the wound diminished, the IFAP-containing reactive astrocytes close to the wound persisted. Concurrently, they began to change from a stellate form to an elongated shape, with their longitudinal axes radiating from the wound. The immunoreactivity of this IFAP started to diminish at 20 days postlesion, and by 30 days postlesion, it was not observed in the remaining gliotic cells. These results demonstrate that reactive astrocytes induced by stab-wound injury can be divided into two subtypes: persistent IFAP-70/280 kDa-containing cells which are close to the wound in the area of the glial scar and transient IFAP-70/280 kDa-negative cells which are farther from the wound. The reappearance of IFAP-70/280 kDa also suggests that some reactive astrocytes have the capacity to recapitulate early developmental stages.
我们在放射状胶质细胞及其直接衍生物中鉴定出一种早期出现的中间丝相关蛋白（IFAP-70/280 kDa）。这种IFAP在成年中枢神经系统中不存在。在本研究中，我们检测了大鼠大脑刺伤诱导的反应性星形胶质细胞中这种早期胶质细胞分化特征的重新表达。双标免疫荧光显微镜显示，损伤后36小时，IFAP-70/280 kDa存在于伤口附近区域的一些GFAP阳性星形胶质细胞中。随着胶质增生反应的进展，IFAP阳性反应性星形胶质细胞的数量增加，损伤后5-6天，IFAP-70/280 kDa存在于紧邻伤口组织中的大多数肥大星形胶质细胞中。损伤后8天，远离伤口的IFAP阴性反应性星形胶质细胞数量减少，而靠近伤口的含IFAP的反应性星形胶质细胞持续存在。同时，它们开始从星状形态转变为细长形状，其纵轴从伤口放射状延伸。这种IFAP的免疫反应性在损伤后20天开始减弱，损伤后30天，在剩余的胶质增生细胞中未观察到。这些结果表明，刺伤损伤诱导的反应性星形胶质细胞可分为两种亚型：在胶质瘢痕区域靠近伤口的持续含IFAP-70/280 kDa的细胞和远离伤口的短暂IFAP-70/280 kDa阴性细胞。IFAP-70/280 kDa的重新出现还表明，一些反应性星形胶质细胞有能力重现早期发育阶段。
