Dataset Information

Chimeric Antisense Oligonucleotide Conjugated to ?-Tocopherol.

ABSTRACT: We developed an efficient system for delivering short interfering RNA (siRNA) to the liver by using ?-tocopherol conjugation. The ?-tocopherol-conjugated siRNA was effective and safe for RNA interference-mediated gene silencing in vivo. In contrast, when the 13-mer LNA (locked nucleic acid)-DNA gapmer antisense oligonucleotide (ASO) was directly conjugated with ?-tocopherol it showed markedly reduced silencing activity in mouse liver. Here, therefore, we tried to extend the 5'-end of the ASO sequence by using 5'-?-tocopherol-conjugated 4- to 7-mers of unlocked nucleic acid (UNA) as a "second wing." Intravenous injection of mice with this ?-tocopherol-conjugated chimeric ASO achieved more potent silencing than ASO alone in the liver, suggesting increased delivery of the ASO to the liver. Within the cells, the UNA wing was cleaved or degraded and ?-tocopherol was released from the 13-mer gapmer ASO, resulting in activation of the gapmer. The ?-tocopherol-conjugated chimeric ASO showed high efficacy, with hepatic tropism, and was effective and safe for gene silencing in vivo. We have thus identified a new, effective LNA-DNA gapmer structure in which drug delivery system (DDS) molecules are bound to ASO with UNA sequences.

SUBMITTER: Nishina T

PROVIDER: S-EPMC4345304 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature

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Chimeric Antisense Oligonucleotide Conjugated to α-Tocopherol.

Nishina Tomoko T Numata Junna J Nishina Kazutaka K Yoshida-Tanaka Kie K Nitta Keiko K Piao Wenying W Iwata Rintaro R Ito Shingo S Kuwahara Hiroya H Wada Takeshi T Mizusawa Hidehiro H Yokota Takanori T

Molecular therapy. Nucleic acids 20150113

We developed an efficient system for delivering short interfering RNA (siRNA) to the liver by using α-tocopherol conjugation. The α-tocopherol-conjugated siRNA was effective and safe for RNA interference-mediated gene silencing in vivo. In contrast, when the 13-mer LNA (locked nucleic acid)-DNA gapmer antisense oligonucleotide (ASO) was directly conjugated with α-tocopherol it showed markedly reduced silencing activity in mouse liver. Here, therefore, we tried to extend the 5'-end of the ASO seq ...[more]

PMID: 25584900

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Project description:AimsAmyloidogenic transthyretin (ATTR) amyloidosis is a fatal disease characterized by progressive cardiomyopathy and/or polyneuropathy. AKCEA-TTR-LRx (ION-682884) is a ligand-conjugated antisense drug designed for receptor-mediated uptake by hepatocytes, the primary source of circulating transthyretin (TTR). Enhanced delivery of the antisense pharmacophore is expected to increase drug potency and support lower, less frequent dosing in treatment.Methods and resultsAKCEA-TTR-LRx demonstrated an approximate 50-fold and 30-fold increase in potency compared with the unconjugated antisense drug, inotersen, in human hepatocyte cell culture and mice expressing a mutated human genomic TTR sequence, respectively. This increase in potency was supported by a preferential distribution of AKCEA-TTR-LRx to liver hepatocytes in the transgenic hTTR mouse model. A randomized, placebo-controlled, phase 1 study was conducted to evaluate AKCEA-TTR-LRx in healthy volunteers (ClinicalTrials.gov: NCT03728634). Eligible participants were assigned to one of three multiple-dose cohorts (45, 60, and 90 mg) or a single-dose cohort (120 mg), and then randomized 10:2 (active : placebo) to receive a total of 4 SC doses (Day 1, 29, 57, and 85) in the multiple-dose cohorts or 1 SC dose in the single-dose cohort. The primary endpoint was safety and tolerability; pharmacokinetics and pharmacodynamics were secondary endpoints. All randomized participants completed treatment. No serious adverse events were reported. In the multiple-dose cohorts, AKCEA-TTR-LRx reduced TTR levels from baseline to 2 weeks after the last dose of 45, 60, or 90 mg by a mean (SD) of -85.7% (8.0), -90.5% (7.4), and -93.8% (3.4), compared with -5.9% (14.0) for pooled placebo (P < 0.001). A maximum mean (SD) reduction in TTR levels of -86.3% (6.5) from baseline was achieved after a single dose of 120 mg AKCEA-TTR-LRx .ConclusionsThese findings suggest an improved safety and tolerability profile with the increase in potency achieved by productive receptor-mediated uptake of AKCEA-TTR-LRx by hepatocytes and supports further development of AKCEA-TTR-LRx for the treatment of ATTR polyneuropathy and cardiomyopathy.

Project description:Alpha-1 Antitrypsin (AAT) is a serum protease inhibitor that regulates increased lung protease production induced by cigarette smoking. Mutations in the Serpina1 gene cause AAT to form hepatoxic polymers, which can lead to reduced availability for the protein's primary function and severe liver disease. An AAT antisense oligonucleotide (ASO) was previously identified to be beneficial for the AATD liver disease by blocking the mutated AAT transcripts. Here we hypothesized that knockdown of AAT aggravates murine lung injury during smoke exposure and acute exacerbations of chronic obstructive pulmonary disease (COPD). C57BL/6J mice were randomly divided into 4 groups each for the smoking and smoke-flu injury models. The ASO and control (No-ASO) were injected subcutaneously starting with smoking or four days prior to influenza infection and then injected weekly at 50 mg/kg body weight. ASO treatment during a 3-month smoke exposure significantly decreased the serum and lung AAT expression, resulting in increased Cela1 expression and elastase activity. However, despite the decrease in AAT, neither the inflammatory cell counts in the bronchoalveolar lavage fluid (BALF) nor the lung structural changes were significantly worsened by ASO treatment. We observed significant differences in inflammation and emphysema due to smoke exposure, but did not observe an ASO treatment effect. Similarly, with the smoke-flu model, differences were only observed between smoke-flu and room air controls, but not as a result of ASO treatment. Off-target effects or compensatory mechanisms may account for this finding. Alternatively, the reduction of AAT with ASO treatment, while sufficient to protect from liver injury, may not be robust enough to lead to lung injury. The results also suggest that previously described AAT ASO treatment for AAT mutation related liver disease may attenuate hepatic injury without being detrimental to the lungs. These potential mechanisms need to be further investigated in order to fully understand the impact of AAT inhibition on protease-antiprotease imbalance in the murine smoke exposure model.

Dataset Information

Chimeric Antisense Oligonucleotide Conjugated to ?-Tocopherol.

Publications

Chimeric Antisense Oligonucleotide Conjugated to α-Tocopherol.

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