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Efficient, non-toxic anion transport by synthetic carriers in cells and epithelia

Nature Chemistry volume 8, pages 24–32 (2016)Cite this article

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Abstract

Transmembrane anion transporters (anionophores) have potential for new modes of biological activity, including therapeutic applications. In particular they might replace the activity of defective anion channels in conditions such as cystic fibrosis. However, data on the biological effects of anionophores are scarce, and it remains uncertain whether such molecules are fundamentally toxic. Here, we report a biological study of an extensive series of powerful anion carriers. Fifteen anionophores were assayed in single cells by monitoring anion transport in real time through fluorescence emission from halide-sensitive yellow fluorescent protein. A bis-(p-nitrophenyl)ureidodecalin shows especially promising activity, including deliverability, potency and persistence. Electrophysiological tests show strong effects in epithelia, close to those of natural anion channels. Toxicity assays yield negative results in three cell lines, suggesting that promotion of anion transport may not be deleterious to cells. We therefore conclude that synthetic anion carriers are realistic candidates for further investigation as treatments for cystic fibrosis.

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Figure 1: Structures of anionophores.
Figure 2: Evaluation of anionophore-mediated anion transport in YFP-FRT cells by fluorescence microscopy.
Figure 3: Anion transport by the decalin bis-urea 13 is concentration-dependent and persistent.
Figure 4: Anionophores generate persistent apical membrane Cl− currents in YFP-FRT epithelia
Figure 5: Evaluation of anionophore toxicity using MDCK, FRT and HeLa cells.

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Acknowledgements

The authors thank A.S. Verkman for the gift of FRT cells expressing YFP-H148Q/I152L, the Wolfson Bioimaging Facility (University of Bristol) and M.A. Jepson and A.D. Leard for help and advice. This work was supported by the Engineering and Physical Sciences Research Council (grants nos. EP/F03623X/1 and EP/J00961X/1). O.J. thanks K. Rissanen for a postdoctoral position through the Academy of Finland (grant no. 265328) and the University of Jyväskylä for an international mobility grant.

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Authors and Affiliations

  1. School of Physiology and Pharmacology, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK

    Hongyu Li & David N. Sheppard

  2. School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK

    Hennie Valkenier, Luke W. Judd, Peter R. Brotherhood, Sabir Hussain, James A. Cooper, Ondřej Jurček, Hazel A. Sparkes & Anthony P. Davis

  3. Department of Chemistry, University of Jyväskylä, PO Box 35, Jyväskylä, FI-40014, Finland

    Ondřej Jurček

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Contributions

A.P.D., D.N.S. and H.L. conceived and designed the experiments. H.L., H.V., L.W.J., P.R.B., S.H., J.A.C., O.J. and H.A.S. performed the research. A.P.D., D.N.S, H.L. and H.V. analysed the data and co-wrote the manuscript. A.P.D. and D.N.S. directed the study.

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Correspondence to David N. Sheppard or Anthony P. Davis.

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The authors declare no competing financial interests.

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Crystallographic data for compound 13 (CIF 851 kb)

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Li, H., Valkenier, H., Judd, L. et al. Efficient, non-toxic anion transport by synthetic carriers in cells and epithelia. Nature Chem 8, 24–32 (2016). https://doi.org/10.1038/nchem.2384

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