Dissecting the Mechanisms of Transcriptional Synergy in Response to Proinflammatory Cytokines in Endothelial Cells

Combinatorial cytokine signaling is implicated in the pathogenesis of diseases of the cardiovascular system ranging from acute combinatorial cytokine signaling observed in complications from SARS-COVID19 infection to chronic combinatorial cytokine signaling observed in atherosclerosis. There remains a large gap of our understanding how combinatorial cytokine signaling interface to drive proinflammatory programs. We hypothesize that stimulation of HAECs with IFNg and TNFa promotes synergistic gene transcription through the coordinated interplay between p65, STAT1, p300/CBP, and BRD4. Our work demonstrates through the generation of novel statistical framework that IFNg and TNFa dual stimulation for one hour results in the synergistic induction of a small subset of proinflammatory genes. Prolonged dual cytokine stimulation results in synergistic levels of protein expression and cell death. Treatment with A-485 and/or JQ1 reduces levels of synergistic gene and protein expression along with improvements in cell viability. Defining synergistic responses and identifying their unique transcriptional dependencies opens the door to understanding how disparate cytokine signaling drives proinflammatory responses and how these responses can be targeted.