A Miniaturized Screen of a Schistosoma mansoni Serotonergic G Protein-Coupled Receptor Identifies Novel Classes of Parasite-Selective Inhibitors. PLoS Pathog 2016 May;12(5):e1005651
Date
05/18/2016Pubmed ID
27187180Pubmed Central ID
PMC4871480DOI
10.1371/journal.ppat.1005651Scopus ID
2-s2.0-84973334825 (requires institutional sign-in at Scopus site) 30 CitationsAbstract
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.
Author List
Chan JD, McCorvy JD, Acharya S, Johns ME, Day TA, Roth BL, Marchant JSAuthors
Jonathan S. Marchant PhD Chair, Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of WisconsinJohn McCorvy PhD Assistant Professor in the Cell Biology, Neurobiology and Anatomy department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsBlotting, Western
Drug Evaluation, Preclinical
Female
HEK293 Cells
High-Throughput Screening Assays
Humans
Mice
Receptors, G-Protein-Coupled
Schistosoma mansoni
Schistosomiasis mansoni