ZFIN ID: ZDB-PUB-180713-14
A High-Content Screen Reveals New Small-Molecule Enhancers of Ras/Mapk Signaling as Probes for Zebrafish Heart Development
Saydmohammed, M., Vollmer, L.L., Onuoha, E.O., Maskrey, T.S., Gibson, G., Watkins, S.C., Wipf, P., Vogt, A., Tsang, M.
Date: 2018
Source: Molecules   23(7): (Journal)
Registered Authors: Tsang, Michael
Keywords: Cognition Network Technology, Fgf signaling, heart development, high-content analysis, high-throughput screening, probe discovery, zebrafish
MeSH Terms:
  • Animals
  • Embryo, Nonmammalian/drug effects
  • Embryo, Nonmammalian/metabolism
  • Extracellular Signal-Regulated MAP Kinases/metabolism
  • Fibroblast Growth Factors/metabolism
  • Heart/drug effects
  • Heart/embryology*
  • High-Throughput Screening Assays/methods*
  • MAP Kinase Signaling System*/drug effects
  • Molecular Probes/chemistry*
  • Organ Size/drug effects
  • Small Molecule Libraries/chemistry
  • Small Molecule Libraries/pharmacology*
  • Zebrafish/embryology*
  • ras Proteins/metabolism*
PubMed: 29997348 Full text @ Molecules
Zebrafish is the preferred vertebrate model for high throughput chemical screens to discover modulators of complex biological pathways. We adapted a transgenic zebrafish line, Tg(dusp6:EGFP), which reports on fibroblast growth factor (Fgf)/Ras/Mapk activity, into a quantitative, high-content chemical screen to identify novel Fgf hyperactivators as chemical probes for zebrafish heart development and regeneration. We screened 10,000 compounds from the TimTec ActiProbe library, and identified several structurally distinct classes of molecules that enhanced Fgf/Ras/Mapk signaling. We chose three agents-ST020101, ST011282, and ST006994-for confirmatory and functional studies based on potency, repeatability with repurchased material, favorable whole organism toxicity, and evidence of structure⁻activity relationships. Functional follow-up assays confirmed that all three compounds induced the expression of Fgf target genes during zebrafish embryonic development. Moreover, these compounds increased cardiac progenitor populations by effecting a fate change from endothelial to cardiac progenitors that translated into increased numbers of cardiomyocytes. Interestingly, ST006994 augmented Fgf/Ras/Mapk signaling without increasing Erk phosphorylation, suggesting a molecular mechanism of action downstream of Erk. We posit that the ST006994 pharmacophore could become a unique chemical probe to uncover novel mechanisms of Fgf signaling during heart development and regeneration downstream of the Mapk signaling node.