Structural remodeling of fibrous astrocytes after axonal injury.
Structural remodeling of fibrous astrocytes after axonal injury.
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DOI：
10.1523/jneurosci.3605-10.2010
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发表时间：
2010-10-20
期刊：
影响因子：
--
通讯作者：
Jakobs TC
中科院分区：
文献类型：
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作者：
Sun D;Lye-Barthel M;Masland RH;Jakobs TC
反应性星形胶质细胞是许多CNS损伤和神经变性的病理标志。其特征在于索马和突起的肥大以及胶质细胞酸性蛋白（GFAP）表达的增加。由于细胞在免疫染色中彼此模糊，因此对单个反应性星形胶质细胞的行为以及单个星形胶质细胞联合收割机如何形成胶质瘢痕知之甚少。我们已经研究了纤维星形胶质细胞轴突变性的反应，使用转基因小鼠株表达增强型绿色荧光蛋白（EGFP）的小亚群的星形胶质细胞。视神经和胼胝体中的纤维星形胶质细胞最初通过索马和突起的肥大对损伤作出反应。它们收缩了它们的主要过程，简化了它们的形状，大大减少了它们的空间覆盖范围。在挤压后三天，定量分析显示初级突起的厚度增加了近两倍，离开索马的初级突起的数量减少了一半，空间覆盖范围减少了八倍。在接下来的一周里，它们部分地重新延长了长过程，恢复到接近正常的形态和广泛的空间重叠。由此产生的胶质瘢痕由星形胶质细胞突起的不规则排列组成，与它们最初的有序排列形成对比。这些变化与灰质反应性原生质星形胶质细胞的报告形成鲜明对比，其中过程和分支的数量增加，但细胞在整个对损伤的反应过程中继续保持非重叠的个体区域。
Reactive astrocytes are a pathological hallmark of many CNS injuries and neurodegenerations. They are characterized by hypertrophy of the soma and processes and an increase in the expression of glial fibrillary acidic protein (GFAP). Because the cells obscure each other in immunostaining, little is known about the behavior of a single reactive astrocyte, nor how single astrocytes combine to form the glial scar. We have investigated the reaction of fibrous astrocytes to axonal degeneration using a transgenic mouse strain expressing enhanced green fluorescent protein (EGFP) in small subsets of astrocytes. Fibrous astrocytes in the optic nerve and corpus callosum initially react to injury by hypertrophy of the soma and processes. They retract their primary processes, simplifying their shape and dramatically reducing their spatial coverage. At three days post-crush, quantitative analysis revealed nearly a two-fold increase in the thickness of the primary processes, a halving of the number of primary processes leaving the soma and an eight-fold reduction in the spatial coverage. In the subsequent week, they partially re-extend long processes, returning to a near normal morphology and an extensive spatial overlap. The resulting glial scar consists of an irregular array of astrocyte processes, contrasting with their original orderly arrangement. These changes are in distinct contrast to those reported for reactive protoplasmic astrocytes of the grey matter, in which the number of processes and branchings increase, but the cells continue to maintain non-overlapping individual territories throughout their response to injury.