Correlation between adenine nucleotide-induced cyclic AMP elevation and extracellular adenosine formation in NG108-15 cells.
We previously demonstrated that extracellular adenine nucleotides induced cyclic AMP elevation in NG108-15 cells. This response was resistant to adenosine deaminase (ADA) and the ecto-5'-nucleotidase (CD73) inhibitor alpha,beta-methylene ADP (alpha,beta-MeADP), but was inhibited by both P1- and P2-receptor antagonists. In the present study, we investigated the relationship between adenine nucleotide-induced cyclic AMP elevation and extracellular adenosine formation. ATP, AMP and beta,gamma-methylene ATP (beta,gamma-MeATP) were time-dependently metabolized to adenosine in NG108-15 cells. Adenosine formations from ATP, AMP and beta,gamma-MeATP were not affected by alpha,beta-MeADP, but suppressed by the P2-receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). A close correlation between extracellular adenosine formation and cyclic AMP increasing effects were obtained with several adenine nucleotide agonists in NG108-15 cells as well as their parent cell line C6Bu-1 and N18TG-2 cells, all of which possess functional adenosine A2 receptors. When NG108-15 cells were incubated with [3H]ATP or [3H]AMP in the presence of ADA, [3H]adenosine was found to distribute dominantly on the cell surface. NG108-15 cells expressed mRNA for the ecto-ATPase and nucleotide pyrophosphatase, but not for CD73. These results suggest that local adenosine formation by an ecto-enzyme distinct from CD73 is involved in adenine nucleotide-induced cyclic AMP formation in NG108-15 cells.
Ohkubo
S
S
Department of Cellular Signaling, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
Kimura
J
J
Matsuoka
I
I
D000227:Adenine Nucleotides / Q000378:metabolism*; D000241:Adenosine / Q000096:biosynthesis*; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000378:metabolism / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D000242:Cyclic AMP / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005110:Extracellular Space / Q000378:metabolism; D009708:Nucleotidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D000227:Adenine Nucleotides; D004791:Enzyme Inhibitors; D058919:Purinergic P2 Receptor Antagonists; D012333:RNA, Messenger; C523965:alpha,beta-methyleneadenosine 5'-diphosphate; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D000249:Adenosine Monophosphate; D011732:Pyridoxal Phosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D009708:Nucleotidases; C030287:nucleotidase; D000241:Adenosine