Better explicating the strengths and shortcomings of these models will help refine projections and improve transparency in the years ahead.
Image credit: Witsawat.S.
Edited by Jennifer M. Heemstra, Emory University, and accepted by Editorial Board Member Thomas E. Mallouk March 18, 2019 (received for review December 6, 2018)
Significance
Multivalent ligands have tremendous potential as therapeutic agents; however, their efficacy is limited by delivery issues, poor cell permeability, and toxicity. We report here a strategy wherein multivalent ligands are designed to be intrinsically cell-penetrating, allowing them to target the expanded trinucleotide repeat sequences of DNA and RNA that cause myotonic dystrophy type 1 (DM1). The multivalent ligand studied shows cell permeability and low toxicity both in cells and in mice. Importantly, the ligand reduced or eliminated DM1 defects in DM1 cells and in vivo, validating the multivalent strategy. The approach should be broadly applicable to other repeat expansion diseases and to any multivalent oligomeric therapeutic agent whose activity can accommodate structural elements that mimic cell-penetrating peptides.
Abstract
Developing highly active, multivalent ligands as therapeutic agents is challenging because of delivery issues, limited cell permeability, and toxicity. Here, we report intrinsically cell-penetrating multivalent ligands that target the trinucleotide repeat DNA and RNA in myotonic dystrophy type 1 (DM1), interrupting the disease progression in two ways. The oligomeric ligands are designed based on the repetitive structure of the target with recognition moieties alternating with bisamidinium groove binders to provide an amphiphilic and polycationic structure, mimicking cell-penetrating peptides. Multiple biological studies suggested the success of our multivalency strategy. The designed oligomers maintained cell permeability and exhibited no apparent toxicity both in cells and in mice at working concentrations. Furthermore, the oligomers showed important activities in DM1 cells and in a DM1 liver mouse model, reducing or eliminating prominent DM1 features. Phenotypic recovery of the climbing defect in adult DM1 Drosophila was also observed. This design strategy should be applicable to other repeat expansion diseases and more generally to DNA/RNA-targeted therapeutics.
- multivalent ligand
- DNA/RNA-targeting therapeutics
- cell-penetrating peptide mimic
- myotonic dystrophy type 1
- trinucleotide repeat expansion diseases
Footnotes
↵1J.L. and Y.B. contributed equally to this work.
- ↵2To whom correspondence may be addressed. Email: sczimmer{at}illinois.edu or kalsotra{at}illinois.edu.
Author contributions: J.L., Y.B., U.V.C., S.P., K.Y., L.M.L., L.D.H., H.Y.E.C., A.K., and S.C.Z. designed research; J.L., Y.B., U.V.C., S.P., K.Y., L.M.L., L.D.H., and J.F.S. performed research; J.L., U.V.C., S.P., L.D.H., J.F.S., H.Y.E.C., and A.K. analyzed data; and J.L., Y.B., L.D.H., H.Y.E.C., A.K., and S.C.Z. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission. J.M.H. is a guest editor invited by the Editorial Board.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1820827116/-/DCSupplemental.
Published under the PNAS license.
Intrinsically cell-penetrating multivalent and multitargeting ligands for myotonic dystrophy type 1
Article Classifications
- Physical Sciences
- Chemistry
- Biological Sciences
- Biochemistry
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