Transcriptional synergy in human aortic endothelial cells is vulnerable to combination p300/CBP and BET bromodomain inhibition
Ronan C. Bracken,
Lindsay M. Davison,
Dennis P. Buehler,
Maci E. Fulton,
Emily E. Carson,
Quanhu Sheng,
Lindsey K. Stolze,
Christelle Guillermier,
Matthew L. Steinhauser,
Jonathan D. Brown
Affiliations
Ronan C. Bracken
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
Lindsay M. Davison
Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
Dennis P. Buehler
Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
Maci E. Fulton
Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
Emily E. Carson
Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
Quanhu Sheng
Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN 3723, USA
Lindsey K. Stolze
Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN 3723, USA
Christelle Guillermier
Harvard Medical School, Boston, MA 02115, USA; Center for NanoImaging, Cambridge MA 02115, USA; Department of Medicine, Division of Genetics, Brigham and Women’s Hospital, Boston, MA 02115, USA
Matthew L. Steinhauser
Aging Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
Jonathan D. Brown
Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Corresponding author
Summary: Combinatorial signaling by proinflammatory cytokines synergizes to exacerbate toxicity to cells and tissue injury during acute infections. To explore synergism at the gene-regulatory level, we investigated the dynamics of transcription and chromatin signaling in response to dual cytokines by integrating nascent RNA imaging mass spectrometry, RNA sequencing, amplification-independent mRNA quantification, assay for transposase-accessible chromatin using sequencing (ATAC-seq), and transcription factor profiling. Costimulation with interferon-gamma (IFNγ) and tumor necrosis factor alpha (TNFα) synergistically induced a small subset of genes, including the chemokines CXCL9, -10, and -11. Gene induction coincided with increased chromatin accessibility at non-coding regions enriched for p65 and STAT1 binding sites. To discover coactivator dependencies, we conducted a targeted chemogenomic screen of transcriptional inhibitors followed by modeling of inhibitor dose-response curves. These results identified high efficacy of either p300/CREB-binding protein (CBP) or bromodomain and extra-terminal (BET) bromodomain inhibitors to disrupt induction of synergy genes. Combination p300/CBP and BET bromodomain inhibition at half-maximal inhibitory concentrations (subIC50) synergistically abrogated IFNγ/TNFα-induced chemokine gene and protein levels.
