Small molecules dorsomorphin and LDN-193189 inhibit myostatin/GDF8 signaling and promote functional myoblast differentiation
- J Biol Chem. 2015 Feb 6;290(6):3390-404. doi: 10.1074/jbc.M114.604397.
- 1. From the Institute for Chemistry-Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
- 2. the Structural Genomics Consortium, University of Oxford, Oxford OX3 7DQ, United Kingdom, and.
- 3. the Muscle Research Unit, Experimental and Clinical Research Center, 13125 Berlin, Germany.
- 4. From the Institute for Chemistry-Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany, [email protected].
GDF8, or myostatin, is a member of the TGF-β superfamily of secreted polypeptide growth factors. GDF8 is a potent negative regulator of myogenesis both in vivo and in vitro. We found that GDF8 signaling was inhibited by the small molecule ATP competitive inhibitors dorsomorphin and LDN-193189. These compounds were previously shown to be potent inhibitors of BMP signaling by binding to the BMP type I receptors ALK1/2/3/6. We present the crystal structure of the type II receptor ActRIIA with dorsomorphin and demonstrate that dorsomorphin or LDN-193189 target GDF8 induced SMAD2/3 signaling and repression of myogenic transcription factors. As a result, both inhibitors rescued myogenesis in myoblasts treated with GDF8. As revealed by quantitative live cell microscopy, treatment with dorsomorphin or LDN-193189 promoted the contractile activity of myotubular networks in vitro. We therefore suggest these inhibitors as suitable tools to promote functional myogenesis.