High-affinity P2Y2 and low-affinity P2X7 receptor interaction modulates ATP-mediated calcium signaling in murine osteoblasts
Fig 1
ATP-induced Ca2+ response characteristics are conserved across murine osteoblast lines.
Fura2-loaded BMP2-transfected C2C12 osteoblastic cells (C2-OB), bone-marrow-derived osteoblasts (BM-OB), or compact-bone-derived osteoblasts (CB-OB) were stimulated with ATP (10−8 to 10−3 M), changes in [Ca2+]i were recorded, and characteristic parameters of individual cell-level Ca2+ responses were quantified. (A) Representative ATP-induced Ca2+ signature responses for different osteoblastic lines. Recording duration: 120 s. (B) Activation time, magnitude and oscillatory characteristics of Ca2+ responses in different osteoblastic cells were aligned to obtain consensus on dose-dependency behaviours (see S1 Fig for intermediary alignment steps). Data are response means, normalized to peak dose-response. Solid curves: Loess curves fit to normalized response means. Vertical solid lines: peak magnitude; Vertical dashed lines: peak oscillatory activity; CI: confidence interval, M: molar concentration.