Polyglutamation of antifolates is not required for induction of extracellular release of adenosine or expression of their anti-inflammatory effects.
Methotrexate (MTX) exerts an anti-inflammatory effect, reportedly by enhancing the release of adenosine, through an accumulation of 5-amino-4-imidazolecarboxamide ribonucleotide (AICAR). To examine the role of polyglutamation in promoting anti-inflammatory effects by antifolates, we tested whether a new antifolate designed to be resistant to intracellular polyglutamation (MX-68) exhibited anti-inflammatory effects and stimulated adenosine release. Both MX-68 and MTX (at concentrations greater than 0.1 microM) increased the release of adenosine from Daudi cells in vitro. Inhibition of AICAR synthesis suppressed adenosine release by MX-68 and MTX. The anti-inflammatory effects of antifolates were estimated using the murine air pouch model, in which a BALB/c mouse was intraperitoneally injected with MX-68 or MTX once a week for 3 weeks. MX-68 (0.5 mg kg(-1) week(-1)), as well as MTX, inhibited infiltration of leukocytes into the air pouch. This inhibitory effect was suppressed in the presence of an adenosine A(2) receptor antagonist, 3,7-dimethyl-1-propargylxanthine (DMPX). These results suggest that MX-68, like MTX, exerts anti-inflammatory effects through the accumulation of AICAR and release of adenosine. These results suggest that polyglutamation of antifolate is not required for expression of anti-inflammatory effects.
Urakawa
K
K
Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135, Komakado, Shizuoka 412-8513, Gotemba, Japan. urakawakzm@chugai-pharm.co.jp
Mihara
M
M
Suzuki
T
T
Kawamura
A
A
Akamatsu
K
K
Takeda
Y
Y
Kamatani
N
N
D015074:2-Aminoadipic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism / Q000494:pharmacology*; D002417:Cattle; D002460:Cell Line; D005110:Extracellular Space / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005493:Folic Acid Antagonists / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008727:Methotrexate / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D011624:Pteroylpolyglutamic Acids / Q000378:metabolism*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005493:Folic Acid Antagonists; C104193:N-(1-((2,4-diamino-6-pteridinyl)methyl)-3,4-dihydro -2H-1,4-benzothiazine-7-carbonyl)-L-2-aminoadipic acid; D011624:Pteroylpolyglutamic Acids; D015074:2-Aminoadipic Acid; D000241:Adenosine; D008727:Methotrexate