Elevated pressure induced astrocyte damage in the optic nerve
Elevated pressure induced astrocyte damage in the optic nerve
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DOI：
10.1016/j.brainres.2008.09.044
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发表时间：
2008-12-09
期刊：
影响因子：
2.9
通讯作者：
Yu, Dao-Yi
中科院分区：
文献类型：
--
作者：
Balaratnasingam, Chandrakumar;Morgan, William H.;Yu, Dao-Yi
星形胶质细胞与中枢神经系统(CNS)神经元保持着密切的关系，在调节其生化环境中起着至关重要的作用。众所周知，中枢神经系统中神经组织压力的升高会导致轴突变性，但星形胶质细胞在神经损伤早期的反应还没有得到详细的研究。视神经是研究中枢神经系统轴突损伤的一个容易获得的模型。我们实验室以前的工作表明，眼压的急剧升高会导致视神经头内轴突细胞骨架的改变和轴突运输迟缓。轴突改变以时间依赖的方式发生，改变的幅度与眼压上升的持续时间成正比。用胶质纤维酸性蛋白(GFAP)作为星形胶质细胞的标记物，研究了压力对视神经头星形胶质细胞结构的影响。使用共聚焦显微镜，我们发现眼压升高导致星形胶质细胞的形态变化，这与先前关于肿胀的报道一致。此外，这些星形胶质细胞内的GFAP强度也降低。这些变化以时间依赖的方式发生，变化的时间顺序与轴突变化的时间顺序一致。星形胶质细胞改变的区域未见细胞凋亡的迹象。本研究结果为神经组织压力升高早期既有星形胶质细胞损伤又有轴索损伤提供了证据。(C)2008爱思唯尔B.V.保留所有权利。
Astrocytes maintain an intimate relationship with central nervous system (CNS) neurons and play a crucial role in regulating their biochemical environment. A rise in neural tissue pressure in the CNS is known to lead to axonal degeneration however the response of astrocytes during the early stages of neural injury has not been studied in great detail. The optic nerve is a readily accessible model in which to study CNS axonal injury. Previous work from our laboratory has shown that an acute increase in intraocular pressure (IOP) results in axonal cytoskeleton changes and axonal transport retardation within the optic nerve head. Axonal changes occurred in a time-dependent manner with the magnitude of change being proportional to the duration of the IOP rise. Using glial fibrillary acidic protein (GFAP) as a marker of astrocytes we have now studied pressure induced changes in astrocyte structure in the optic nerve head. Using confocal microscopy we found that an increase in IOP resulted in morphological changes in the astrocytes that were consistent with previous reports of swelling. In addition there was also a decrease in GFAP intensity within these astrocytes. These changes occurred in a time-dependent manner with the chronology of change coinciding with that of axonal change. There was no evidence of apoptosis in regions where astrocyte changes were found. The present results provide evidence that in the early stages of neural tissue pressure rise there are both astrocyte and axonal injury. (C) 2008 Elsevier B.V. All rights reserved.