Efficient in vivo delivery of siRNA to the liver by conjugation of α-tocopherol
Efficient in vivo delivery of siRNA to the liver by conjugation of α-tocopherol
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DOI：
10.1038/mt.2008.14
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发表时间：
2008-04-01
影响因子：
12.4
通讯作者：
Yokota, Takanori
中科院分区：
文献类型：
--
作者：
Nishina, Kazutaka;Unno, Toshinori;Yokota, Takanori
RNA干扰是靶点特异性敲除基因表达的有力工具。然而，有效和安全的体内递送短干扰RNA(SiRNA)到靶器官，这是治疗应用必不可少的，还没有建立。在本研究中，我们使用α-生育酚(维生素E)作为体内siRNA的载体分子，它有自己的生理转运途径，可以到达大多数器官。α-生育酚在5‘端与27/29聚体siRNA的反义链共价结合(Toc-siRNA)。27/29聚体Toc-siRNA被设计为被DICER切割，在释放α-生育酚后产生成熟的21/21聚体siRNA。与抗氧化活性有关的α-生育酚的C6羟基被取消。利用该载体，静脉注射针对载脂蛋白B(ApoB)的2 mg/kg的Toc-siRNA，可有效减少肝脏内源性apoB信使RNA(MRNA)的表达。ApoB基因的表达下调表现为肝脏中脂滴的聚集。生化和病理分析均未发现干扰素(IFN)的诱导或其他明显副作用。这些结果表明，Toc-siRNA对RNA干扰介导的体内基因沉默是有效和安全的。
RNA interference is a powerful tool for target-specific knockdown of gene expression. However, efficient and safe in vivo delivery of short interfering RNA (siRNA) to the target organ, which is essential for therapeutic applications, has not been established. In this study we used alpha-tocopherol (vitamin E), which has its own physiological transport pathway to most of the organs, as a carrier molecule of siRNA in vivo. The alpha-tocopherol was covalently bound to the antisense strand of 27/29-mer siRNA at the 5'-end (Toc-siRNA). The 27/29-mer Toc-siRNA was designed to be cleaved by Dicer, producing a mature form of 21/21-mer siRNA after releasing alpha-tocopherol. The C6 hydroxyl group of alpha-tocopherol, associated with antioxidant activity, was abolished. Using this new vector, intravenous injection of 2 mg/kg of Toc-siRNA, targeting apolipoprotein B (apoB), achieved efficient reduction of endogenous apoB messenger RNA (mRNA) in the liver. The downregulation of apoB mRNA was confirmed by the accumulation of lipid droplets in the liver as a phenotype. Neither induction of interferons (IFNs) nor other overt side effects were revealed by biochemical and pathological analyses. These findings indicate that Toc-siRNA is effective and safe for RNA interference-mediated gene silencing in vivo.