Open AccessRecombinant Ecto-5′-Nucleotidase (CD73) Has Long Lasting Antinociceptive Effects That are Dependent on Adenosine A1Receptor Activation
Author(s) -
Nathaniel A. Sowa,
Meagen K Voss,
Mark J. Zylka
Publication year - 2010
Publication title -
molecular pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.081
H-Index - 83
ISSN - 1744-8069
DOI - 10.1186/1744-8069-6-20
Subject(s) - adenosine , pharmacology , nociception , chemistry , adenosine a1 receptor , nucleotidase , adenosine receptor , receptor , biochemistry , medicine , agonist
Background Ecto-5'-nucleotidase (NT5E, also known as CD73) hydrolyzes extracellular adenosine 5'-monophosphate (AMP) to adenosine in nociceptive circuits. Since adenosine has antinociceptive effects in rodents and humans, we hypothesized that NT5E, an enzyme that generates adenosine, might also have antinociceptive effects in vivo . Results To test this hypothesis, we purified a soluble version of mouse NT5E (mNT5E) using the baculovirus expression system. Recombinant mNT5E hydrolyzed AMP in biochemical assays and was inhibited by α,β-methylene-adenosine 5'-diphosphate (α,β-me-ADP; IC 50 = 0.43 μM), a selective inhibitor of NT5E. mNT5E exhibited a dose-dependent thermal antinociceptive effect that lasted for two days when injected intrathecally in wild-type mice. In addition, mNT5E had thermal antihyperalgesic and mechanical antiallodynic effects that lasted for two days in the complete Freund's adjuvant (CFA) model of inflammatory pain and the spared nerve injury (SNI) model of neuropathic pain. In contrast, mNT5E had no antinociceptive effects when injected intrathecally into adenosine A 1 receptor ( A 1 R, Adora1 ) knockout mice. Conclusion Our data indicate that the long lasting antinociceptive effects of mNT5E are due to hydrolysis of AMP followed by activation of A 1 R. Moreover, our data suggest recombinant NT5E could be used to treat chronic pain and to study many other physiological processes that are regulated by NT5E.