Chromatin immunoprecipitation (ChIP) scanning identifies primary glucocorticoid receptor target genes

Abstract

The global physiological effects of glucocorticoids are well established, and the framework of transcriptional regulation by the glucocorticoid receptor (GR) has been described. However, the genes directly under GR control that trigger these physiological effects are largely unknown. To address this issue in a single cell type, we identified glucocorticoid-responsive genes in A549 human lung adenocarcinoma cells by microarray analysis and quantitative real-time PCR. Reduction of GR expression by RNA interference diminished the effects of dexamethasone on all tested target genes, thus confirming the essential role of GR in glucocorticoid-regulated gene expression. To identify primary GR target genes, in which GR is a component of the transciptional regulatory complex, we developed a strategy that uses chromatin immunoprecipitation to scan putative regulatory regions of target genes for sites occupied by specifically bound GR. We screened 11 glucocorticoid-regulated genes, and we identified GR-binding regions for eight of them (five induced and three repressed). Thus, our approach provides a means for rapid identification of primary GR target genes and glucocorticoid-response elements, which will facilitate analyses of transcriptional regulatory mechanisms and determination of hormone-regulated gene networks.

Anti-inflammatory functions of glucocorticoid-induced genes

“…GCs upregulate glucocorticoid inducible leucine zipper (GILZ) expression in T cells (Asselin-Labat et al, 2004;D'Adamio et al, 1997;Mittelstadt and Ashwell, 2001;Riccardi et al, 2001), mast cells , eosinophils (Arthaningtyas et al, 2005), epithelial (Bhalla et al, 2006;Chivers et al, 2006;Eddleston et al, 2007;Soundararajan et al, 2005;Wang et al, 2004), and myeloid cells (Berrebi et al, 2003;Cohen et al, 2006;Ehrchen et al, 2007). Relatively high basal GILZ expression has also been recorded in brain, lung and skeletal muscle .…”

“…GR interacted in vivo with a distal 5' region of the GILZ locus that contains four divergent GRE sequences (Wang et al, 2004). Both these GR binding sites and FoxO3…”

Differences in FKBP51 Regulation Following Chronic Social Defeat Stress Correlate with Individual Stress Sensitivity: Influence of Paroxetine Treatment

“…To test whether varying FKBP51 levels would result in an altered GR sensitivity, we also measured the expression of a known GR target gene, MT-1 (Wang et al, 2004). MT-1 mRNA expression in the CA1 of the hippocampus was correlated to both FKBP51 levels in the same region ( Figure 5a) and struggling time in the FST (Figure 5b).…”

Dual regulation of glucocorticoid-induced leucine zipper (GILZ) by the glucocorticoid receptor and the PI3-kinase/AKT pathways in multiple myeloma

“…The promoter of GILZ contains 6 glucocorticoid responsive elements (GRE), along with binding sites for forkhead box class O (FOXO) family proteins, signal transducer and activator of transcription 6 (STAT6), nuclear factor of activated T cells (NFAT), Octamer, and c-myc [18][19][20]. The regulation of GILZ expression has been studied in a murine T lymphocyte line where FOXO3 was shown to activate GILZ expression independent of GCs [18,19].…”