Prakash Thazha P, Lima Walt F, Murray Heather M, Li Wenyu, Kinberger Garth A, Chappell Alfred E, Gaus Hans, Seth Punit P, Bhat Balkrishen, Crooke Stanley T, Swayze Eric E
Isis Pharmaceuticals Inc., 2855 Gazelle Ct, Carlsbad, CA 92010, USA
Isis Pharmaceuticals Inc., 2855 Gazelle Ct, Carlsbad, CA 92010, USA.
Nucleic Acids Res. 2015 Mar 31;43(6):2993-3011. doi: 10.1093/nar/gkv162. Epub 2015 Mar 9.
The ss-siRNA activity in vivo requires a metabolically stable 5'-phosphate analog. In this report we used crystal structure of the 5'-phosphate binding pocket of Ago-2 bound with guide strand to design and synthesize ss-siRNAs containing various 5'-phosphate analogs. Our results indicate that the electronic and spatial orientation of the 5'-phosphate analog was critical for ss-siRNA activity. Chemically modified ss-siRNA targeting human apoC III mRNA demonstrated good potency for inhibiting ApoC III mRNA and protein in transgenic mice. Moreover, ApoC III ss-siRNAs were able to reduce the triglyceride and LDL cholesterol in transgenic mice demonstrating pharmacological effect of ss-siRNA. Our study provides guidance to develop surrogate phosphate analog for ss-siRNA and demonstrates that ss-siRNA provides an alternative strategy for therapeutic gene silencing.
体内的单链小干扰RNA（ss-siRNA）活性需要代谢稳定的5'-磷酸类似物。在本报告中，我们利用与引导链结合的Ago-2的5'-磷酸结合口袋的晶体结构来设计和合成含有各种5'-磷酸类似物的ss-siRNA。我们的结果表明，5'-磷酸类似物的电子和空间取向对ss-siRNA活性至关重要。靶向人载脂蛋白C III（apoC III）mRNA的化学修饰ss-siRNA在转基因小鼠中显示出良好的抑制apoC III mRNA和蛋白质的效力。此外，ApoC III ss-siRNA能够降低转基因小鼠中的甘油三酯和低密度脂蛋白胆固醇，证明了ss-siRNA的药理作用。我们的研究为开发ss-siRNA的替代磷酸类似物提供了指导，并证明ss-siRNA为治疗性基因沉默提供了一种替代策略。
