RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA.
Department of Neurology, Massachusetts General Institute for Neurodegenerative Disease, Boston, MA, USA.
Nat Biotechnol. 2019 Aug;37(8):884-894. doi: 10.1038/s41587-019-0205-0. Epub 2019 Aug 2.
Sustained silencing of gene expression throughout the brain using small interfering RNAs (siRNAs) has not been achieved. Here we describe an siRNA architecture, divalent siRNA (di-siRNA), that supports potent, sustained gene silencing in the central nervous system (CNS) of mice and nonhuman primates following a single injection into the cerebrospinal fluid. Di-siRNAs are composed of two fully chemically modified, phosphorothioate-containing siRNAs connected by a linker. In mice, di-siRNAs induced the potent silencing of huntingtin, the causative gene in Huntington's disease, reducing messenger RNA and protein throughout the brain. Silencing persisted for at least 6 months, with the degree of gene silencing correlating to levels of guide strand tissue accumulation. In cynomolgus macaques, a bolus injection of di-siRNA showed substantial distribution and robust silencing throughout the brain and spinal cord without detectable toxicity and with minimal off-target effects. This siRNA design may enable RNA interference-based gene silencing in the CNS for the treatment of neurological disorders.
使用小干扰 RNA（siRNA）在整个大脑中持续沉默基因表达尚未实现。在这里，我们描述了一种 siRNA 结构，即二价 siRNA（di-siRNA），它在单次注射到脑脊液后，能够在小鼠和非人类灵长类动物的中枢神经系统（CNS）中实现强大、持续的基因沉默。di-siRNA 由两条完全化学修饰、含硫代磷酸酯的 siRNA 通过连接子连接而成。在小鼠中，di-siRNA 诱导亨廷顿病致病基因 huntingtin 的有效沉默，从而减少整个大脑中的信使 RNA 和蛋白质。沉默持续至少 6 个月，基因沉默的程度与引导链组织积累的水平相关。在食蟹猴中，di-siRNA 的单次注射显示出在大脑和脊髓中的广泛分布和强大的沉默，没有可检测的毒性和最小的脱靶效应。这种 siRNA 设计可能能够实现基于 RNA 干扰的 CNS 基因沉默，用于治疗神经疾病。
