Novel endosomolytic compounds enable highly potent delivery of antisense oligonucleotides

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Title: Novel endosomolytic compounds enable highly potent delivery of antisense oligonucleotides
Authors: Bost, JP
Ojansivu, M
Munson, MJ
Wesén, E
Gallud, A
Gupta, D
Gustafsson, O
Saher, O
Rädler, J
Higgins, SG
Lehto, T
Holme, MN
Dahlén, A
Engkvist, O
Strömstedt, P-E
Andersson, S
Edvard Smith, CI
Stevens, MM
Esbjörner, EK
Collén, A
El Andaloussi, S
Item Type: Journal Article
Abstract: The therapeutic and research potentials of oligonucleotides (ONs) have been hampered in part by their inability to effectively escape endosomal compartments to reach their cytosolic and nuclear targets. Splice-switching ONs (SSOs) can be used with endosomolytic small molecule compounds to increase functional delivery. So far, development of these compounds has been hindered by a lack of high-resolution methods that can correlate SSO trafficking with SSO activity. Here we present in-depth characterization of two novel endosomolytic compounds by using a combination of microscopic and functional assays with high spatiotemporal resolution. This system allows the visualization of SSO trafficking, evaluation of endosomal membrane rupture, and quantitates SSO functional activity on a protein level in the presence of endosomolytic compounds. We confirm that the leakage of SSO into the cytosol occurs in parallel with the physical engorgement of LAMP1-positive late endosomes and lysosomes. We conclude that the new compounds interfere with SSO trafficking to the LAMP1-positive endosomal compartments while inducing endosomal membrane rupture and concurrent ON escape into the cytosol. The efficacy of these compounds advocates their use as novel, potent, and quick-acting transfection reagents for antisense ONs.
Issue Date: 1-Mar-2022
Date of Acceptance: 8-Feb-2022
DOI: 10.1038/s42003-022-03132-2
ISSN: 2399-3642
Publisher: Nature Research
Journal / Book Title: Communications Biology
Volume: 5
Issue: 1
Copyright Statement: © The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit
Sponsor/Funder: Wellcome Trust
Funder's Grant Number: 098411/Z/12/Z
Publication Status: Published
Conference Place: England
Open Access location:
Article Number: ARTN 185
Appears in Collections:Materials
Faculty of Natural Sciences

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