Sustained Interleukin-1β Exposure Modulates Multiple Steps in Glucocorticoid Receptor Signaling, Promoting Split-Resistance to the Transactivation of Prominent Anti-Inflammatory Genes by Glucocorticoids

Figure 2

Sustained IL-1β reduces the whole-cell GR protein level after a DEX challenge. Cells were pretreated for 16 h with either vehicle or 5 ng/mL IL-1β and then treated for 2 h with vehicle (b1, veh/veh), 5 ng/mL IL-1β alone (b2, veh/IL-1β), 10⁻⁸ M DEX alone (b3, veh/DEX), simultaneous addition of 5 ng/mL IL-1β + 10⁻⁸ M DEX (b4, veh/IL-1β + DEX) or sustained IL-1β conditions (b5, IL-1β/IL-1β + DEX), as indicated in the table. Whole cell lysates were prepared and analyzed by Western blot with anti-GR and -β-actin antibodies. (a) Blots of a representative experiment (). (b) Quantitation of whole cell GR protein by densitometry. Data are represented as mean ± SEM percentage of total GR protein amount as compared to veh/veh treatment. ^# and ^##, difference in GR protein levels between veh/IL-1β-treated (b2) or veh/DEX-treated (b3) and veh/veh-treated cells (b1), respectively. , difference in GR protein levels between IL-1β/IL-1β + DEX-treated (b5) and veh/DEX-treated cells (b3).

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