Adenosine Deaminase Inhibition Prevents Clostridium difficile Toxin A-Induced Enteritis in Mice

作者：Torquato de Araujo Junqueira Ana Flavia; Martins Dias Adriana Abalen; Vale Mariana Lima; Gruner Turco Spilborghs Graziela Machado; Bossa Aline Siqueira; Lima Bruno Bezerra; Carvalho Alex Fiorini; Guerrant Richard Littleton; Ribeiro Ronaldo Albuquerque; Brito Gerly Anne^*

来源：Infection and Immunity, 2011, 79(2): 653-662.

DOI：10.1128/IAI.01159-10

Toxin A (TxA) is able to induce most of the classical features of Clostridium difficile-associated disease in animal models. The objective of this study was to determine the effect of an inhibitor of adenosine deaminase, EHNA [erythro-9-(2-hydroxy-3-nonyl)-adenine], on TxA-induced enteritis in C57BL6 mice and on the gene expression of adenosine receptors. EHNA (90 mu mol/kg) or phosphate-buffered saline (PBS) was injected intraperitoneally (i.p.) 30 min prior to TxA (50 mu g) or PBS injection into the ileal loop. A(2A) adenosine receptor agonist (ATL313; 5 nM) was injected in the ileal loop immediately before TxA (50 mu g) in mice pretreated with EHNA. The animals were euthanized 3 h later. The changes in the tissue were assessed by the evaluation of ileal loop weight/length and secretion volume/length ratios, histological analysis, myeloperoxidase assay (MPO), the local expression of inducible nitric oxide synthase (NOS2), pentraxin 3 (PTX3), NF-kappa B, tumor necrosis factor alpha (TNF-alpha), and interleukin-1 beta (IL-1 beta) by immunohistochemistry and/or quantitative reverse transcription-PCR (qRT-PCR). The gene expression profiles of A(1), A(2A), A(2B), and A(3) adenosine receptors also were evaluated by qRT-PCR. Adenosine deaminase inhibition, by EHNA, reduced tissue injury, neutrophil infiltration, and the levels of proinflammatory cytokines (TNF-alpha and IL-1 beta) as well as the expression of NOS2, NF-kappa B, and PTX3 in the ileum of mice injected with TxA. ATL313 had no additional effect on EHNA action. TxA increased the gene expression of A(1) and A(2A) adenosine receptors. Our findings show that the inhibition of adenosine deaminase by EHNA can prevent Clostridium difficile TxA-induced damage and inflammation possibly through the A(2A) adenosine receptor, suggesting that the modulation of adenosine/adenosine deaminase represents an important tool in the management of C. difficile-induced disease.

• 出版日期2011-2