Identification and characterization of potent and selective aquaporin-3 and aquaporin-7 inhibitors

Research output: Contribution to journalArticle

Abstract

The aquaglyceroporins are a subfamily of aquaporins that conduct both water and glycerol. Aquaporin-3 (AQP3) has an important physiological function in renal water reabsorption, and AQP3-mediated hydrogen peroxide (H2O2) permeability can enhance cytokine signaling in several cell types. The related aquaglyceroporin AQP7 is required for dendritic cell chemokine responses and antigen uptake. Selective small-molecule inhibitors are desirable tools for investigating the biological and pathological roles of these and other AQP isoforms. Here, using a calcein fluorescence quenching assay we screened a library of 7360 drug-like small molecules for inhibition of mouse AQP3 water permeability. Hit confirmation and expansion with commercially available substances identified the ortho-chloride-containing compound DFP00173, which inhibited mouse and human AQP3 with an IC50 of ~0.1-0.4 μM but had low efficacy toward mouse AQPs 7 and 9. Surprisingly, inhibitor specificity testing revealed that the methylurea-linked compound Z433927330, a partial AQP3 inhibitor (IC50 ~0.7-0.9 μM), is a potent and efficacious inhibitor of mouse AQP7 water permeability (IC50 ~0.2 μM). Stopped-flow light-scattering measurements confirmed that DFP00173 and Z433927330 inhibit AQP3 glycerol permeability in human erythrocytes. Moreover, DFP00173, Z433927330, and the previously identified AQP9 inhibitor RF03176 blocked aquaglyceroporin H2O2 permeability. Molecular docking to AQP3, AQP7, and AQP9 homology models suggested interactions between these inhibitors and aquaglyceroporins at similar binding sites. DFP00173 and Z433927330 constitute selective and potent AQP3 and AQP7 inhibitors, respectively, and contribute to a set of isoform-specific aquaglyceroporin inhibitors that will facilitate the evaluation of these AQP isoforms as drug targets.

Details

Authors
Organisations
External organisations
  • University of Bari Aldo Moro
  • 2A Pharma, Sweden
  • Aalborg University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Medical Biotechnology
Original languageEnglish
Pages (from-to) 7377-7387
Number of pages20
JournalJournal of Biological Chemistry
Volume294
Issue number18
Early online date2019 Mar 11
Publication statusPublished - 2019
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

Published under license by The American Society for Biochemistry and Molecular Biology, Inc.