Cercosporamide inhibits bone morphogenetic protein receptor type I kinase activity in zebrafish.

Jelmer Hoeksma,Gerard C M Van Der Zon,Jeroen Den Hertog,Peter Ten Dijke

doi:10.1242/dmm.045971

Abstract

ABSTRACTZebrafish models are well-established tools for investigating the underlying mechanisms of diseases. Here, we identified cercosporamide, a metabolite from the fungus Ascochyta aquiliqiae, as a potent bone morphogenetic protein receptor (BMPR) type I kinase inhibitor through a zebrafish embryo phenotypic screen. The developmental defects in zebrafish, including lack of the ventral fin, induced by cercosporamide were strikingly similar to the phenotypes caused by renowned small-molecule BMPR type I kinase inhibitors and inactivating mutations in zebrafish BMPRs. In mammalian cell-based assays, cercosporamide blocked BMP/SMAD-dependent transcriptional reporter activity and BMP-induced SMAD1/5-phosphorylation. Biochemical assays with a panel of purified recombinant kinases demonstrated that cercosporamide directly inhibited kinase activity of type I BMPRs [also called activin receptor-like kinases (ALKs)]. In mammalian cells, cercosporamide selectively inhibited constitutively active BMPR type I-induced SMAD1/5 phosphorylation. Importantly, cercosporamide rescued the developmental defects caused by constitutively active Alk2 in zebrafish embryos. We believe that cercosporamide could be the first of a new class of molecules with potential to be developed further for clinical use against diseases that are causally linked to overactivation of BMPR signaling, including fibrodysplasia ossificans progressiva and diffuse intrinsic pontine glioma.This article has an associated First Person interview with the first author of the paper.

Highlights

Zebrafish (Danio rerio) is an attractive model for studying the biological effects of genetic mutations and chemical compounds in vivo
We demonstrate that cercosporamide inhibited Bone morphogenetic proteins (BMPs)/SMAD signaling in mammalian cells and zebrafish embryos
Several embryos displayed the formation of secondary tissue, which was not observed in the non-treated control (Fig. 1A,B). This phenotype is strikingly similar to the phenotype induced by known bone morphogenetic protein receptor (BMPR) type I kinase inhibitors such as dorsomorphin, LDN-193189 and DMH-1 (Fig. 1C), and to BMP mutants previously reported in multiple studies (Gebruers et al, 2013; Yang and Thorpe, 2011; Yu et al, 2008)

Summary

Introduction

Zebrafish (Danio rerio) is an attractive model for studying the biological effects of genetic mutations and chemical compounds in vivo. Zebrafish are vertebrates with a highly conserved physiology that develop all organs and primary tissues in several days (Kimmel et al, 1995). Zebrafish embryos are transparent, which makes development easy to follow and defects. Large numbers of eggs can be obtained, owing to their high fecundity, making zebrafish the perfect model for genetic studies and high-throughput compound screens (den Hertog, 2005; Wiley et al, 2017)

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