Local synthesis of axonal and presynaptic RNA in squid model systems
Local synthesis of axonal and presynaptic RNA in squid model systems
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DOI：
10.1111/j.1460-9568.2007.05304.x
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发表时间：
2007-01-01
影响因子：
3.4
通讯作者：
Giuditta, Antonio
中科院分区：
文献类型：
--
作者：
Eyman, Maria;Cefaliello, Carolina;Giuditta, Antonio
轴突和神经末梢中蛋白质合成的活跃系统的存在提出了相应RNA的细胞起源的问题。我们目前的实验表明，除了可能起源于神经元胞体外，轴浆RNA还可能起源于轴突周围的胶质细胞，而突触前RNA则起源于邻近的细胞，可能是胶质细胞。事实上，在灌流的鱿鱼巨型轴突中，新合成的RNA被轴突去极化或神经胶质谷氨酸和乙酰胆碱受体激动剂强烈刺激。同样，将鱿鱼视叶切片与[H-3]尿苷孵育后，从视网膜光感受器神经元的神经末梢衍生的大型突触体内会显著积聚[H-3]RNA。由于这些神经元的胞体位于视叶之外，数据表明突触前RNA是在局部合成的，推测是由突触周围神经胶质细胞合成的。总体而言，我们的结果支持这样的观点，即轴突和突触前区域具有局部基因表达系统，这可能被证明是这些体外神经元域的维持和可塑性所必需的。
The presence of active systems of protein synthesis in axons and nerve endings raises the question of the cellular origin of the corresponding RNAs. Our present experiments demonstrate that, besides a possible derivation from neuronal cell bodies, axoplasmic RNAs originate in periaxonal glial cells and presynaptic RNAs derive from nearby cells, presumably glial cells. Indeed, in perfused squid giant axons, delivery of newly synthesized RNA to the axon perfusate is strongly stimulated by axonal depolarization or agonists of glial glutamate and acetylcholine receptors. Likewise, incubation of squid optic lobe slices with [H-3]uridine leads to a marked accumulation of [H-3]RNA in the large synaptosomes derived from the nerve terminals of retinal photoreceptor neurons. As the cell bodies of these neurons lie outside the optic lobe, the data demonstrate that presynaptic RNA is locally synthesized, presumably by perisynaptic glial cells. Overall, our results support the view that axons and presynaptic regions are endowed with local systems of gene expression which may prove essential for the maintenance and plasticity of these extrasomatic neuronal domains.