Discovery by organism based high-throughput screening of new multi-stage compounds affecting Schistosoma mansoni viability, egg formation and production

PLoS Negl Trop Dis. 2017 Oct 6;11(10):e0005994. doi: 10.1371/journal.pntd.0005994. eCollection 2017 Oct.

Abstract

Schistosomiasis, one of the most prevalent neglected parasitic diseases affecting humans and animals, is caused by the Platyhelminthes of the genus Schistosoma. Schistosomes are the only trematodes to have evolved sexual dimorphism and the constant pairing with a male is essential for the sexual maturation of the female. Pairing is required for the full development of the two major female organs, ovary and vitellarium that are involved in the production of different cell types such as oocytes and vitellocytes, which represent the core elements of the whole egg machinery. Sexually mature females can produce a large number of eggs each day. Due to the importance of egg production for both life cycle and pathogenesis, there is significant interest in the search for new strategies and compounds not only affecting parasite viability but also egg production. Here we use a recently developed high-throughput organism-based approach, based on ATP quantitation in the schistosomula larval stage of Schistosoma mansoni for the screening of a large compound library, and describe a pharmacophore-based drug selection approach and phenotypic analyses to identify novel multi-stage schistosomicidal compounds. Interestingly, worm pairs treated with seven of the eight compounds identified show a phenotype characterized by defects in eggshell assemblage within the ootype and egg formation with degenerated oocytes and vitelline cells engulfment in the uterus and/or oviduct. We describe promising new molecules that not only impair the schistosomula larval stage but also impact juvenile and adult worm viability and egg formation and production in vitro.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Drug Discovery / methods*
  • Female
  • High-Throughput Screening Assays / methods
  • Humans
  • Larva / drug effects
  • Life Cycle Stages / drug effects
  • Male
  • Oocytes / drug effects
  • Oocytes / physiology
  • Ovum / drug effects
  • Schistosoma mansoni / drug effects*
  • Schistosoma mansoni / growth & development
  • Schistosoma mansoni / isolation & purification
  • Schistosoma mansoni / physiology*
  • Schistosomiasis mansoni / parasitology
  • Schistosomicides / pharmacology*
  • Small Molecule Libraries

Substances

  • Schistosomicides
  • Small Molecule Libraries
  • Adenosine Triphosphate

Grants and funding

This work was partially supported by the CNR (National Research Council)-CNCCS (Collezione Nazionale di Composti Chimici e Centro di screening) Project DSB.AD011.001.003 “Rare, Neglected and Poverty Related Diseases - Schistodiscovery” (GR, AB) and by MIUR (Ministero dell'Istruzione Università e Ricerca) Project PRIN 20154JRJPP_006 "Towards multi-stage drugs to fight poverty related and neglected parasitic diseases: Synthetic and natural compounds directed against Leishmania, Plasmodium and Schistosoma life stages and assessment of their mechanisms of action" (GR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.