Highly efficient gene silencing in mouse brain by overhanging‐duplex oligonucleotides via intraventricular route

Abstract

Gapmer‐type antisense oligonucleotides have not yet been approved for the treatment of central nervous system diseases, whereas steric‐blocking‐type antisense oligonucleotides have been well‐developed for clinical use. We here characterize a new type of double‐stranded oligonucleotides, overhanging‐duplex oligonucleotides, which are composed of the parent gapmer and its extended complementary RNA. By intracerebroventricular injection, overhanging oligonucleotides show greater silencing potency with more efficient delivery into mouse brains than the parent single‐stranded gapmer. Structure–activity relationship analyses reveal that the potency enhancement requires 13‐mer or more overhanging oligonucleotides with a phosphorothioate backbone. Overhanging oligonucleotides provide a new platform of therapeutic oligonucleotides for gene modulation in the central nervous system.

Change of intracellular calcium level causes acute neurotoxicity by antisense oligonucleotides via CSF route

“…injection into mice. 32 However, we have not yet reported that ASO3 has moderate neurotoxicity at the acute phase. We chose these three ASOs because we elucidate the general mechanisms underlying acute neurotoxicity via the intrathecal (IT) route using these ASOs with different lengths and chemical modifications.…”

“…The chosen three toxic oligonucleotides with a PS backbone were two DNA/LNA gapmer-type ASOs 32 targeting mouse beta-site amyloid precursor protein cleaving enzyme ( Bace1 ) and microtubule-associated protein tau ( Mapt ) mRNAs, respectively, and one 20mer DNA/MOE gapmer-type ASO 33 targeting metastasis-associated lung adenocarcinoma transcript 1 ( Malat1 ) long non-coding RNA (as shown in Table S1 ). ASO1 was reported by Hagedorn et al.…”

“…i.c.v. bolus administrations were performed as previously described 32 with the following modifications. For ASO injection with pretreatment of other reagents, mice were administrated with the modulators at 10 μL/2 min.…”

DNAzymes: Expanding the Potential of Nucleic Acid Therapeutics

“…3 ). Binding of the leash sequence to the DNAzyme resulted in the formation of a duplex (made up of double-stranded DNA or RNA) and allowed the “escort” of the DNAzyme to target tissues [ 84 , 92–94 ]. In addition, DNAzyme stability is increased owing to the DNA/RNA or DNA/DNA duplex region being inherently more stable than single-stranded (ssDNA) DNA (DNAzyme) in the cellular environment.…”

Recent Advances in RNA Therapy and Its Carriers to Treat the Single-Gene Neurological Disorders

“…Up to date, three gapmers have been approved for clinical use, Mipomersen, Inotersen, and Volanesorsen. In addition to the single stranded oligonucleotides, double stranded DNA-RNA heteroduplex oligonucleotides (HDO) [ 30 , 31 ], and overhanging heteroduplex oligonucleotides (ODO) [ 32 ] were recently reported to have more potent gene silencing activities.…”