Tissues differentially secrete multiple colony stimulating factors under conditions of homeostasis and inflammation, orientating recruited circulating monocytes to differentiate to macrophage with differing functional phenotypes. Here, we investigated ATP-evoked intracellular Ca2+ responses in human macrophage differentiated with macrophage colony-stimulating factor (M-CSF). Extracellular ATP evoked (EC50 13.3 ± 1.4 µM) robust biphasic intracellular Ca2+ responses that showed a dependency on both metabotropic (P2Y) and ionotropic (P2X) receptors. qRT-PCR and immunocytochemistry revealed the expression of P2Y1, P2Y2, P2Y6, P2Y11, P2Y13, P2X1, P2X4, P2X5, and P2X7. Pharmacological analysis revealed contribution of only P2X4 and P2Y11 to the Ca2+ response evoked by maximal ATP concentrations (100 µM). This study reveals the contribution of P2X4 and P2Y11 receptor activation to ATP-evoked intracellular Ca2+ responses, and makes comparison with macrophage differentiated using granulocyte colony-stimulating factor (GM-CSF).
- Calcium signaling