Figure 3: MEK/ERK inhibition worsens Ca²⁺ signaling capacity in the case of TNFα and IL-8.

Pretreatment with the MEK/ERK inhibitor U0126 at 10uM for 20 minutes before treatment with a panel of growth factors and cytokines at 10ng/mL for 30 minutes did not protect ATP-stimulated Ca²⁺ bursting responses in HUVEC. Stimulation with 100uM ATP only is depicted as Control in black bars, stimulation with ATP after growth factor or cytokine treatment is depicted in light gray bars, and ATP after U0126 pretreatment prior to growth factor or cytokine treatment is in dark gray bars. Data is shown as mean count of Ca²⁺ bursts in cells that responded with at least 3 Ca²⁺ bursts upon initial ATP stimulation, ± SEM for at least 80 cells from at least 4 separate dishes of pooled cells. Statistical analysis was done by Rank-sum test, with * indicating p<0.05 and Kruskal-Wallis with + indicating p<0.05.