Figure 3.

A20 can mediate signaling cross-talk between inflammatory stimuli. (A) Quantitated A20 and IκBα mRNA expression in MEFs stimulated with 1 ng/mL TNF or IL-1, as measured by RPA. (B) Nuclear NF-κB activity was measured via EMSA in wild-type, a20^−/−, and iκbα^−/− cells in response to 1 ng/mL TNF or IL-1 stimulation. (C) Simulation of TNF–NF-κB dose response in naïve (black) and IL-1 pretreated (blue) cells. Computational simulations calculated the maximal nuclear NF-κB activity for TNF doses ranging from 10⁻³ to 10³ ng/mL. IL-1 pretreatment was simulated as a 1-h stimulation followed by 1 h of “rest” prior to TNF stimulation. (D) Nuclear NF-κB activity in response to persistent TNF stimulation (0.1 or 1 ng/mL) was measured by EMSA in wild-type and a20^−/− cells that were naïve (−) or pretreated with IL-1 for 1 h, followed by 1 h or 24 h of “rest.”