Axonal mRNA in uninjured and regenerating cortical mammalian axons.
Axonal mRNA in uninjured and regenerating cortical mammalian axons.
复制标题
未损伤和再生的哺乳动物皮质轴突中的轴突 mRNA。
DOI：
10.1523/jneurosci.6130-08.2009
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发表时间：
2009-04-15
期刊：
影响因子：
--
通讯作者：
Cotman CW
中科院分区：
文献类型：
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作者：
Taylor AM;Berchtold NC;Perreau VM;Tu CH;Li Jeon N;Cotman CW
使用一种新型微流体室，可以分离轴突而不受非轴突材料污染，我们首次从幼稚、成熟的中枢神经系统轴突中纯化了 mRNA，并鉴定了 >300 个 mRNA 转录本的存在。我们证明转录本本质上是轴突，并且未受伤的 CNS 轴突中存在的许多转录本与先前在 PNS 损伤条件下的 DRG 轴突中鉴定的转录本重叠。在成熟皮质轴突中检测到的轴突转录物富含蛋白质翻译机制、运输、细胞骨架成分和线粒体维护。接下来，我们研究了轴突切开后轴突 mRNA 库如何变化，揭示了与细胞内运输、线粒体和细胞骨架相关的许多基因转录本在损伤两天后显示出定位减少。相比之下，与轴突靶向和突触功能相关的基因转录物显示出在再生皮质轴突中的定位增加，这表明轴突生长和靶向的能力增加，并且在损伤后再生中枢神经系统轴突中对突触形成和突触前功能的支持增加。我们的数据表明，中枢神经系统轴突包含许多具有不同功能的 mRNA 种类，并表明，与无脊椎动物和三七总皂甙轴突一样，中枢神经系统轴突在局部合成蛋白质，保持一定程度的细胞体自主性。
Using a novel microfluidic chamber that allows the isolation of axons without contamination by non-axonal material, we have for the first time purified mRNA from naïve, matured CNS axons, and identified the presence of >300 mRNA transcripts. We demonstrate that the transcripts are axonal in nature, and that many of the transcripts present in uninjured CNS axons overlap with those previously identified in PNS injury-conditioned DRG axons. The axonal transcripts detected in matured cortical axons are enriched for protein translational machinery, transport, cytoskeletal components, and mitochondrial maintenance. We next investigated how the axonal mRNA pool changes after axotomy, revealing that numerous gene transcripts related to intracellular transport, mitochondria and the cytoskeleton show decreased localization two days after injury. In contrast, gene transcripts related to axonal targeting and synaptic function show increased localization in regenerating cortical axons, suggesting that there is an increased capacity for axonal outgrowth and targeting, and increased support for synapse formation and presynaptic function in regenerating CNS axons after injury. Our data demonstrate that CNS axons contain many mRNA species of diverse functions, and suggest that, like invertebrate and PNS axons, CNS axons synthesize proteins locally, maintaining a degree of autonomy from the cell body.