A2AR activation modifies RANKL/OPG secretion from osteoblast. A) RANKL, OPG, osteocalcin, Runx2, and osteonectin mRNA fold change in murine osteoblast precursors after 24 h challenge with osteogenic medium in the presence of CGS21680, alone or with ZM241385, compared with control (n = 4). B) RANKL and OPG mRNA fold change in murine osteoblast precursors after 24 h challenge with osteogenic medium in the presence of CGS21680, alone or with ZM241385, and in combination with Sema3A compared with control (n = 4). ***P < 0.001, **P < 0.01, *P > 0.05 (ANOVA).