Abstract 14580: Determining the Transcription Factor Network Controlling Gene Locus Activity of the Inotropic Factor S100A1 in the Heart

• Published in: Circulation (New York, N.Y.) Vol. 138; no. Suppl_1 Suppl 1; p. A14580
• Main Authors: Busch, Martin, Adrian, Lukas, Guenther, Fabian, Haas, Jan, Meder, Benjamin, Dieterich, Christoph, Boerries, Melanie, Katus, Hugo A, Most, Patrick
• Format: Journal Article
• Language: English
• Published: by the American College of Cardiology Foundation and the American Heart Association, Inc 06.11.2018
• ISSN: 0009-7322; 1524-4539

IntroductionDownregulation of S100A1 gene expression is a hallmark of advanced human heart failure and leads to premature cardiac performance failure and death. As a S100A1 gene replacement therapy is nearing clinical development, understanding the mechanisms that govern S100A1 gene locus regulation may be key to advanced gene editing strategies preventing detrimental cardiac S100A1 downregulation.Methods/ResultsSerial RNAseq. analyses unveiled that the S100A1 expression increases in developing mouse hearts are unexpectedly recapitulated during compensated cardiac hypertrophy. To decipher the transcription factor (TF) network that may similarly activate the S100A1 gene locus both in health and early cardiac disease, we combined computational approaches with serial transcriptome analyses of H9C2 cardioblasts showing robust S100A1 mRNA and protein expression increase upon cardiac differentiation. First, in silico TF consensus motif (con.motif) enrichment from differentially regulated genes was used to predict putatively active TFs. Secondly, only TFs with a con.motif in the S100A1 promoter and validated cardiac abundance by RT-PCR were selected for anti-TF RNA interference screens in H9C2 cells using S100A1 transcription as major read-out. This screen identified ten TFs, including zink finger and coiled-coil TFs (e.g. KLFs) and STATs, with yet unknown abilities to independently positively and negatively regulate S100A1 expression. Thirdly, TFs validated by site-directed mutagenesis S100A1 promoter-luciferase reporter assays were chosen for CRISPR-cas9 mediated inhibition and in vivo tests in compensated cardiac hypertrophy to target S100A1 expression. Fourthly, the TF protein-protein network was reconstructed to identify interactions between TFs regulating S100A1.ConclusionIn summary, we developed an integrated bioinformatical-experimental pipeline to model the TF factor network that drives cardiac S100A1 expression and target novel TFs that will be subject to therapeutic gene editing approaches in vivo to preserve cardiac S100A1 expression in disease models.