Novel Epigenetic Small Molecule Approaches and Single-Cell Analysis for DMD


Single Cell Analysis Approaches

Poster Number: 200


Lisa Maves, PhD, Jean-Baptiste Dupont, PhD, Gist H. Farr III, Shawn Luttrell, PhD, Melanie Morris, Arianna Gomez, Thao Pham, David Mack, PhD


1. Seattle Children's Research Institute, 2. I-Stem, INSERM/UEVE UMR 861, 3. Seattle Children's Research Institute, 4. Institute for Stem Cell and Regenerative Medicine, University of Washington, 5. University of Washington, 6. University of Washington, 7. University of Washington, 8. Institute for Stem Cell and Regenerative Medicine, University of Washington

Duchenne muscular dystrophy (DMD) is a muscle wasting disease caused by mutations in the gene dystrophin. Although DMD is a progressive degenerative disease, there is evidence for early, embryonic-stage defects in myogenesis and gene expression in DMD. By understanding how early myogenic and transcriptional defects initiate and contribute to DMD pathology, we may be better positioned to identify and utilize DMD therapies. Using single-cell RNAseq, our studies have identified one of the earliest known DMD phenotypes: a novel transcriptional trajectory of DMD human induced pluripotent stem cells (hiPSCs) undergoing myogenesis. Many of the genes deregulated in this alternative trajectory are involved in somitogenesis, advocating for a modified muscle development program in DMD cells. Furthermore, we have taken advantage of the zebrafish DMD model to identify conserved transcriptional dysregulation during zebrafish DMD embryonic development. We hypothesize that epigenetic drugs, small molecules that target chromatin modifications and transcriptional regulation, can be used to ameliorate these early DMD transcriptional defects as well as improve downstream DMD pathology. Histone deacetylase inhibitors (HDACi) are one drug class that has shown promise for DMD. However, epigenetic drugs have not been broadly and systematically studied for their benefits for DMD. We performed a novel drug screen of an epigenetic small molecule library using DMD zebrafish and identified a novel combination of epigenetic drugs that rescues muscle degeneration in DMD zebrafish. To test the mechanisms of these new drugs, and to better characterize the epigenetic perturbations in DMD, we are testing whether epigenetic drugs correct the early transcriptional dysregulation observed in DMD hiPSCs and zebrafish embryos. Our studies support the combined use of zebrafish and hiPSCs as models for understanding the developmental epigenetic defects in DMD and for identifying new potential DMD therapies.