title: A Miniaturized Screen of a Schistosoma mansoni Serotonergic G Protein-Coupled Receptor Identifies Novel Classes of Parasite-Selective Inhibitors.
abstract: Schistosomiasis is a tropical parasitic disease afflicting ~200 million people worldwide and current therapy depends on a single drug (praziquantel) which exhibits several non-optimal features. These shortcomings underpin the need for next generation anthelmintics, but the process of validating physiologically relevant targets ('target selection') and pharmacologically profiling them is challenging. Remarkably, even though over a quarter of current human therapeutics target rhodopsin-like G protein coupled receptors (GPCRs), no library screen of a flatworm GPCR has yet been reported. Here, we have pharmacologically profiled a schistosome serotonergic GPCR (Sm.5HTR) implicated as a downstream modulator of PZQ efficacy, in a miniaturized screening assay compatible with high content screening. This approach employs a split luciferase based biosensor sensitive to cellular cAMP levels that resolves the proximal kinetics of GPCR modulation in intact cells. Data evidence a divergent pharmacological signature between the parasitic serotonergic receptor and the closest human GPCR homolog (Hs.5HTR7), supporting the feasibility of optimizing parasitic selective pharmacophores. New ligands, and chemical series, with potency and selectivity for Sm.5HTR over Hs.5HTR7 are identified in vitro and validated for in vivo efficacy against schistosomules and adult worms. Sm.5HTR also displayed a property resembling irreversible inactivation, a phenomenon discovered at Hs.5HTR7, which enhances the appeal of this abundantly expressed parasite GPCR as a target for anthelmintic ligand design. Overall, these data underscore the feasibility of profiling flatworm GPCRs in a high throughput screening format competent to resolve different classes of GPCR modulators. Further, these data underscore the promise of Sm.5HTR as a chemotherapeutically vulnerable node for development of next generation anthelmintics.
authors.affiliation: Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: John D
authors.initials: JD
authors.lastname: Chan
authors.affiliation: Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
authors.forename: John D
authors.initials: JD
authors.lastname: McCorvy
authors.affiliation: Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Sreemoyee
authors.initials: S
authors.lastname: Acharya
authors.affiliation: Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Malcolm E
authors.identifier: 0000-0003-1587-2509
authors.initials: ME
authors.lastname: Johns
authors.affiliation: Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Day
authors.affiliation: Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.|Division of Chemical Biology and Medicinal Chemistry, Eshelmann School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.|National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.
authors.forename: Bryan L
authors.initials: BL
authors.lastname: Roth
authors.affiliation: Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, United States of America.|Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, United States of America.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Marchant
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004353:Drug Evaluation, Preclinical; D005260:Female; D057809:HEK293 Cells; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D051379:Mice; D043562:Receptors, G-Protein-Coupled / Q000032:analysis*; D012550:Schistosoma mansoni / Q000378:metabolism*; D012555:Schistosomiasis mansoni
chemical_list: D043562:Receptors, G-Protein-Coupled