FIGURE 5.

Activation of P2Y₁₁ receptors stimulates the release of soluble TNF receptors. (a) P2RY11‐transfected cells were cultured for 24 h with or without P2Y₁₁ receptor agonist (ATPγS). To confirm that agonist‐mediated cytokine secretion was specific to stimulation of P2Y₁₁ receptors, the cells were also stimulated with agonist in the presence of the specific P2Y₁₁ receptor antagonist NF340. Cell culture supernatants were subjected to a human cytokine antibody array. The G‐Series arrays are semiquantitative featuring fluorescent signal detection (a.u., arbitrary units) (left panel). sTNFR1 release was subsequently validated by ELISA (right panel). IL‐6 and IL‐8, which already emerged from the secretome analysis, served as an internal control. (b) M2 macrophages were treated for 24 h with the P2Y₁₁ receptor agonist (ATPγS). The antagonist NF340 was used to confirm that agonist‐mediated responses were specific to stimulation of P2Y₁₁ receptors. sTNFR1 and sTNFR2 as well as IL‐8 were measured in cell culture supernatants. Data are means ± SEM from five independent donors. *P ≤ .05, significantly different from control; ^# P < .05, significantly different from corresponding concentration of ATPγS only; one‐way ANOVA