IL-4 mediated gene expression profiles in vascular endothelial cells

Endothelial cell activation and dysfunction underlie many vascular disorders, including atherosclerosis and inflammation. Here, we show that interleukin (IL)-4 markedly induced vascular cell adhesion molecule (VCAM)-1, both in cultured endothelial cells and in the intact endothelium in mice. Combined treatment with IL-4 and tumor necrosis factor (TNF)- alpha resulted in further, sustained induction of VCAM-1 expression. IL-4-mediated induction of VCAM-1 and secondary monocyte adhesion was predominantly regulated by the transcription factor, STAT6. Genome-wide survey of IL-4-mediated STAT6 binding from sequential chromatin-immunoprecipitation with deep-sequencing (ChIP-seq) in endothelial cells revealed regions of transient and sustained transcription factor binding. By combining DNA microarrays and ChIP-seq at the same time points, the majority of IL-4-responsive genes were shown to be STAT6-dependent and associated with direct STAT6 binding to their promoter. IL-4-mediated stable binding of STAT6 led to sustained target gene expression. Moreover, our strategy led to the identification of a novel functionally important STAT6 binding site within -16 kb upstream of the VCAM-1 gene. Taken together, these findings support a critical role for STAT6 in mediating IL-4 signal transduction in endothelial cells. Identification of a novel IL-4-mediated VCAM-1 enhancer may provide a foundation for targeted therapy in vascular disease (ChIP-seq data not submitted to GEO).

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Tozawa H, Kanki Y, Suehiro J, Tsutsumi S, Kohro T, Wada Y, Aburatani H, Aird WC, Kodama T, Minami T