Suppression of TNF-alpha production in human mononuclear cells by an adenosine kinase inhibitor.
Adenosine exerts potent anti-inflammatory activities through inhibition of cytokine synthesis by activated monocytes. Adenosine is rapidly phosphorylated intracellularly by adenosine kinase. GP515, an adenosine kinase inhibitor, prevents the phosphorylation of adenosine to AMP and thereby locally enhances the adenosine concentration. GP515 has exhibited significant anti-inflammatory effects in several murine models of inflammation. In this study we investigated the effect of GP515 alone and in combination with exogenous adenosine or with rolipram, a phosphodiesterase inhibitor, on tumor necrosis factor alpha (TNF-alpha) synthesis in human peripheral blood mononuclear cells (PBMC) or whole blood. Lipopolysaccharide (LPS; 10 ng/mL)-stimulated PBMC were incubated in the absence or presence of these substances. GP515 alone showed a dose-dependent suppression of TNF-alpha production with an IC50 of 80 microM. The TNF-alpha-inhibiting effects of adenosine and GP515 were reversed in the presence of the cAMP antagonist (Rp)-cAMPS, supporting the hypothesis of a cAMP-mediated pathway. Combinations of GP515 with either adenosine or rolipram led to an additive inhibition of TNF-alpha synthesis. These experiments are the first to demonstrate efficacy of an adenosine kinase inhibitor in TNF-alpha suppression in cells of human origin. The findings form a basis to investigate these strategies in animal models of TNF-alpha-mediated chronic inflammatory diseases.
Division of Clinical Pharmacology, Medizinische Klinik, Klinikum Innenstadt, University of Munich, Germany.
A
A
Eigler
V
V
Matschke
G
G
Hartmann
S
S
Erhardt
D
D
Boyle
G S
GS
Firestein
S
S
Endres
D000241:Adenosine / Q000378:metabolism* / Q000494:pharmacology; D000248:Adenosine Kinase / Q000037:antagonists & inhibitors* / Q000502:physiology; D000249:Adenosine Monophosphate / Q000096:biosynthesis; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D012263:Ribonucleosides / Q000008:administration & dosage / Q000494:pharmacology*; D020889:Rolipram / Q000008:administration & dosage / Q000494:pharmacology; D015290:Second Messenger Systems / Q000502:physiology; D013873:Thionucleotides / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004791:Enzyme Inhibitors; D010726:Phosphodiesterase Inhibitors; D012263:Ribonucleosides; D013873:Thionucleotides; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; C087698:GP 1-515; C016957:adenosine-3',5'-cyclic phosphorothioate; D000249:Adenosine Monophosphate; D000242:Cyclic AMP; D000248:Adenosine Kinase; D017868:Cyclic AMP-Dependent Protein Kinases; D020889:Rolipram; D000241:Adenosine