Achieving regulation of endogenous gene expression in the central nervous system (CNS) with antisense oligonucleotides (ASOs) administered systemically would facilitate the development of ASO-based therapies for neurological diseases. We demonstrate that DNA/RNA heteroduplex oligonucleotides (HDOs) conjugated to cholesterol or α-tocopherol at the 5′ end of the RNA strand reach the CNS after subcutaneous or intravenous administration in mice and rats. The HDOs distribute throughout the brain, spinal cord and peripheral tissues and suppress the expression of four target genes by up to 90% in the CNS, whereas single-stranded ASOs conjugated to cholesterol have limited activity. Gene knockdown was observed in major CNS cell types and was greatest in neurons and microglial cells. Side effects, such as thrombocytopenia and focal brain necrosis, were limited by using subcutaneous delivery or by dividing intravenous injections. By crossing the blood–brain barrier more effectively, cholesterol-conjugated HDOs may overcome the limited efficacy of ASOs targeting the CNS without requiring intrathecal administration.

通过全身给药的反义寡核苷酸 (ASO) 实现对中枢神经系统 (CNS) 内源性基因表达的调节将有助于开发基于 ASO 的神经系统疾病疗法。我们证明，在小鼠和大鼠皮下或静脉内给药后，在 RNA 链 5' 端与胆固醇或 α-生育酚缀合的 DNA/RNA 异源双链寡核苷酸 (HDO) 到达中枢神经系统。HDOs 分布在整个大脑、脊髓和外周组织中，并在 CNS 中将四个靶基因的表达抑制高达 90%，而与胆固醇结合的单链 ASOs 的活性有限。在主要的 CNS 细胞类型中观察到基因敲低，并且在神经元和小胶质细胞中最为明显。副作用，如血小板减少症和局灶性脑坏死，通过使用皮下给药或分开静脉注射来限制。通过更有效地穿过血脑屏障，胆固醇结合的 HDO 可以克服针对 CNS 的 ASO 的有限功效，而无需鞘内给药。