The soft mechanical signature of glial scars in the central nervous system.
The soft mechanical signature of glial scars in the central nervous system.
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DOI：
10.1038/ncomms14787
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发表时间：
2017-03-20
影响因子：
16.6
通讯作者：
Franze K
中科院分区：
文献类型：
--
作者：
Moeendarbary E;Weber IP;Sheridan GK;Koser DE;Soleman S;Haenzi B;Bradbury EJ;Fawcett J;Franze K
中枢神经系统（CNS）损伤改变了神经组织的分子和细胞组成，并导致神经胶质瘢痕形成，从而抑制受损轴突的再生。哺乳动物神经胶质瘢痕被认为是神经元再生的化学和机械屏障。虽然已经投入了巨大的努力来识别疤痕的分子特征，但对其机械特性知之甚少。在这里，我们的特点是时空变化的弹性刚度损伤大鼠新皮层和脊髓在1.5和3周后，使用原子力显微镜损伤。与其他哺乳动物组织中的瘢痕相反，CNS组织在损伤后显著软化。胶质中间丝（GFAP，波形蛋白）和细胞外基质成分（层粘连蛋白，胶原IV）的表达水平与组织软化相关。由于组织硬度是神经元生长的调节因子，我们的研究结果可能有助于理解为什么哺乳动物神经元在损伤后不能再生。神经胶质瘢痕被认为提供了一个生物化学和机械屏障，神经元再生损伤后，但瘢痕的机械性能还没有详细研究。在这里，作者对受伤的大鼠皮层和脊髓的胶质瘢痕进行了原子力显微镜测量，发现脑组织对损伤做出了反应。
Injury to the central nervous system (CNS) alters the molecular and cellular composition of neural tissue and leads to glial scarring, which inhibits the regrowth of damaged axons. Mammalian glial scars supposedly form a chemical and mechanical barrier to neuronal regeneration. While tremendous effort has been devoted to identifying molecular characteristics of the scar, very little is known about its mechanical properties. Here we characterize spatiotemporal changes of the elastic stiffness of the injured rat neocortex and spinal cord at 1.5 and three weeks post-injury using atomic force microscopy. In contrast to scars in other mammalian tissues, CNS tissue significantly softens after injury. Expression levels of glial intermediate filaments (GFAP, vimentin) and extracellular matrix components (laminin, collagen IV) correlate with tissue softening. As tissue stiffness is a regulator of neuronal growth, our results may help to understand why mammalian neurons do not regenerate after injury. Glial scars are thought to provide a biochemical and mechanical barrier to neuronal regeneration post-injury, but the mechanical properties of the scars have not been studied in detail. Here the authors perform atomic force microscopy measurements of glial scars from the injured rat cortex and spinal cord, and find that brain tissue softens in response to the injury.