title: High-throughput screening of small molecules identifies hepcidin antagonists.
abstract: Anemia of inflammation (AI) is common in patients with infection, autoimmune diseases, cancer, and chronic kidney disease. Unless the underlying condition can be reversed, treatment options are limited to erythropoiesis-stimulating agents with or without intravenous iron therapy, modalities that are not always effective and can cause serious adverse effects. Hepcidin, the iron regulatory hormone, has been identified as a pathogenic factor in the development of AI. To explore new therapeutic options for AI and other iron-related disorders caused by hepcidin excess, we developed a cell-based screen to identify hepcidin antagonists. Of the 70,000 small molecules in the library, we identified 14 compounds that antagonized the hepcidin effect on ferroportin. One of these was fursultiamine, a Food and Drug Administration (FDA)-approved thiamine derivative. Fursultiamine directly interfered with hepcidin binding to its receptor, ferroportin, by blocking ferroportin C326 thiol residue essential for hepcidin binding. Consequently, fursultiamine prevented hepcidin-induced ferroportin ubiquitination, endocytosis, and degradation in vitro and allowed continuous cellular iron export despite the presence of hepcidin, with IC(50) in the submicromolar range. Thiamine, the fursultiamine metabolite, and benfotiamine, another thiamine derivative, did not interfere with the effect of hepcidin on ferroportin. Other FDA-approved thiol-reactive compounds were at least 1000-fold less potent than fursultiamine in antagonizing hepcidin. In vivo, fursultiamine did not reproducibly antagonize the effect of hepcidin on serum iron, likely because of its rapid conversion to inactive metabolites. Fursultiamine is a unique antagonist of hepcidin in vitro that could serve as a template for the development of drug candidates that inhibit the hepcidin-ferroportin interaction.
authors.affiliation: Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
authors.forename: Eileen
authors.initials: E
authors.lastname: Fung
authors.forename: Priscilla
authors.initials: P
authors.lastname: Sugianto
authors.forename: Jason
authors.initials: J
authors.lastname: Hsu
authors.forename: Robert
authors.initials: R
authors.lastname: Damoiseaux
authors.forename: Tomas
authors.initials: T
authors.lastname: Ganz
authors.forename: Elizabeta
authors.initials: E
authors.lastname: Nemeth
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D004705:Endocytosis / Q000187:drug effects / Q000235:genetics; D005666:Fursultiamin / Q000494:pharmacology; D057809:HEK293 Cells; D064451:Hepcidins; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D007501:Iron / Q000378:metabolism; D019189:Iron Metabolism Disorders / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000235:genetics; D059748:Proteolysis / Q000187:drug effects; D011973:Receptors, LDL / Q000235:genetics / Q000378:metabolism; D054852:Small Molecule Libraries / Q000494:pharmacology*; D013831:Thiamine / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination / Q000187:drug effects / Q000235:genetics; D000098742:Ferroportin
chemical_list: D023181:Antimicrobial Cationic Peptides; D027682:Cation Transport Proteins; C578702:HAMP protein, human; C579599:Hamp protein, mouse; D064451:Hepcidins; C573412:LDLR protein, human; D011973:Receptors, LDL; D054852:Small Molecule Libraries; D000098742:Ferroportin; D005666:Fursultiamin; D007501:Iron; D013831:Thiamine