Murashov Alexander K, Chintalgattu Vishnu, Islamov Rustem R, Lever Teresa E, Pak Elena S, Sierpinski Paulina L, Katwa Laxmansa C, Van Scott Michael R
Department of Physiology, Brody School of Medicine, East Carolina University, 600 Moye Blvd., Greenville, NC 27834, USA.
FASEB J. 2007 Mar;21(3):656-70. doi: 10.1096/fj.06-6155com. Epub 2007 Jan 5.
Recent observations demonstrated that translation of mRNAs may occur in axonal processes at sites that are long distances away from the neuronal perikaria. While axonal protein synthesis has been documented in several studies, the mechanism of its regulation remains unclear. The aim of this study was to investigate whether RNA interference (RNAi) may be one of the pathways that control local protein synthesis in axons. Here we show that sciatic nerve contains Argonaute2 nuclease, fragile X mental retardation protein, p100 nuclease, and Gemin3 helicase-components of the RNA-induced silencing complex (RISC). Application of short-interfering RNAs against neuronal beta-tubulin to the sciatic nerve initiated RISC formation, causing a decrease in levels of neuronal beta-tubulin III mRNA and corresponding protein, as well as a significant reduction in retrograde labeling of lumbar motor neurons. Our observations indicate that RNAi is functional in peripheral mammalian axons and is independent from the neuronal cell body or Schwann cells. We introduce a concept of local regulation of axonal translation via RNAi.
最近的观察结果表明，mRNA的翻译可能发生在轴突过程中距离神经元胞体很远的部位。虽然在多项研究中已记录到轴突蛋白合成，但对其调控机制仍不清楚。本研究的目的是调查RNA干扰（RNAi）是否可能是控制轴突局部蛋白合成的途径之一。在此我们表明，坐骨神经含有Argonaute2核酸酶、脆性X智力低下蛋白、p100核酸酶和Gemin3解旋酶——RNA诱导沉默复合体（RISC）的组成成分。将针对神经元β-微管蛋白的小干扰RNA应用于坐骨神经可启动RISC形成，导致神经元β-微管蛋白III mRNA和相应蛋白水平降低，以及腰段运动神经元逆行标记显著减少。我们的观察结果表明，RNAi在周围哺乳动物轴突中具有功能，且独立于神经元胞体或施万细胞。我们引入了通过RNAi对轴突翻译进行局部调控的概念。
