Fig. 6
Conversion of ATP to Adenosine by Two Ecto-nucleotidases Expressed in the OE
(A) Ligand specificity (left, n = 3) and sensitivity (right, n = 4) of A2c receptor examined by cAMP production assay in CHO-K1 cells. A2c is activated only by adenosine with high specificity and sensitivity. Unpaired t test (p = 0.00000016). ∗∗∗p < 0.001.
(B) Double fluorescence in situ hybridization for A2c (magenta) and CD73 or TNAP (green) on OE sections (n = 3–4). Insets: magnified views of the boxed regions. Note the co-expression of A2c and CD73. Scale bar, 20 μm.
(C) Expression of TNAP and CD73 together with A2c in CHO-K1 cells results in A2c activation by AMP, ADP, and ATP as well as adenosine (1 mM) (n = 6). Unpaired t test (AMP, TNAP/CD73 +/–, p = 0.014; –/+, p = 0.0000044; +/+, p = 0.0000067; ADP, +/+, p = 0.0088; ATP, +/+, p = 0.0032).