Genome-Wide Mapping Defines a Role for C/EBPβ and c-Jun in Non-Canonical Cyclic AMP Signalling

Abstract

The novel exchange protein activated by cyclic AMP (EPAC1) activator, I942, induces expression of the suppressor of cytokine signalling 3 (SOCS3) gene, thereby inhibiting interleukin 6 (IL6) inflammatory processes in human umbilical vein endothelial cells (HUVECs). Here we use RNA-SEQ and ChIP-SEQ to determine global gene responses to I942, in comparison with cyclic AMP production promoted by forskolin and rolipram (F/R). We found that I942 promoted significant changes in the RNA expression of 1413 genes, largely associated with microtubule stability and cell cycle progression, whereas F/R regulated 197 genes linked to endothelial cell function, including chemokine production and platelet aggregation. A further 108 genes were regulated by both treatments, including endothelial regulatory genes involved in purinergic signalling and cell junction organization. ChIP-SEQ demonstrated that F/R induced genome-wide recruitment of C/EBPβ and c-Jun transcription factors, whereas I942 promoted recruitment of c-Jun to genes associated with IL6 signalling, with little effect on C/EBPβ activation. Despite this, certain key inflammatory genes, including IL6, VEGF, CCL2/MCP1, VCAM1, SELE and ICAM1 were regulated by I942 without significant c-Jun recruitment, suggesting an additional, indirect mode of action for I942. In this regard, SOCS3 induction by I942 was found to require c-Jun and was associated with suppression of IL6-promoted ERK MAP kinase and AKT activity and induction of ICAM1. Pharmacological inhibition of ERK and AKT also potentiated ICAM1 induction by I942. We therefore propose that c-Jun activation by I942 regulates endothelial gene expression in HUVECs through direct mechanisms, involving recruitment of c-Jun or, as for ICAM1, through indirect regulation of tertiary regulators, including SOCS3.

The P2Y11 receptor of human M2 macrophages activates canonical and IL-1 receptor signaling to translate the extracellular danger signal ATP into anti-inflammatory and pro-angiogenic responses

“…We not only provide evidence for P2Y 11 /IL-1R crosstalk in human M2 macrophages but also identify several novel P2Y 11 target genes. In addition, the cAMP effector Epac1, a well-established inducer of suppressor of cytokine signaling 3 (SOCS3) [ 18 , 19 ], turns out to be a regulator of P2Y 11 /IL-1R signaling. Collectively, the observed signature of response is consistent with a P2Y 11 -driven polarization of anti-inflammatory and pro-angiogenic M2 macrophages.…”

Meta-analysis of transcriptome datasets: An alternative method to study IL-6 regulation in coronavirus disease 2019

“…In other studies, expression of IL-6 and SERPINA1 was increased with disease progression [35] , [36] . SOCS3 expression has been shown to be negatively correlated with IL-6 expression [37] , [38] , [39] , [40] . A negative correlation between expression of TPCN1 and TOMM20 and IL-6 expression has been documented [40] , [41] .…”

Special Issue on “New Advances in Cyclic AMP Signalling”—An Editorial Overview

“…Indeed, the review by Smith et al [ 8 ] details how PKA and EPAC1 suppresses vascular smooth muscle cell proliferation through cytoskeleton remodelling and proliferation-associated gene expression through TEAD transcription factors, highlighting further potential drug targets for the treatment of restenosis after angioplasty, vein graft intimal thickening, and atherosclerosis [ 8 ]. These new cyclic AMP-dependent transcription factor pathways are complemented by new findings from the Yarwood lab that demonstrate that EPAC1 and C/EBP and c-Jun transcription factors mediate cyclic AMP-regulated inflammatory gene expression in vascular endothelial cells, which also provides a new drug-able route for the treatment of inflammation that is associated with vascular disease [ 36 ].…”