Adenosine deaminase inhibition prevents Clostridium difficile toxin A-induced enteritis in mice.
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 μmol/kg) or phosphate-buffered saline (PBS) was injected intraperitoneally (i.p.) 30 min prior to TxA (50 μg) 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 μg) 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-κB, tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) by immunohistochemistry and/or quantitative reverse transcription-PCR (qRT-PCR). The gene expression profiles of A₁, A(2A), A(2B), and A₃ 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-α and IL-1β) as well as the expression of NOS2, NF-κB, and PTX3 in the ileum of mice injected with TxA. ATL313 had no additional effect on EHNA action. TxA increased the gene expression of A₁ 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.
Departamento de Morfologia-Faculdade de Medicina da Universidade Federal do Ceará, Rua Delmiro de Farias, sn-CEP 60.416-030, Fortaleza, Ceará, Brazil.
Ana Flávia Torquato
AF
de Araújo Junqueira
Adriana Abalen Martins
AA
Dias
Mariana Lima
ML
Vale
Graziela Machado Gruner Turco
GM
Spilborghs
Aline Siqueira
AS
Bossa
Bruno Bezerra
BB
Lima
Alex Fiorini
AF
Carvalho
Richard Littleton
RL
Guerrant
Ronaldo Albuquerque
RA
Ribeiro
Gerly Anne
GA
Brito
D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000243:Adenosine Deaminase / Q000378:metabolism*; D058892:Adenosine Deaminase Inhibitors / Q000494:pharmacology*; D000818:Animals; D001427:Bacterial Toxins / Q000008:administration & dosage / Q000633:toxicity*; D001593:Benzyl Compounds / Q000494:pharmacology*; D002097:C-Reactive Protein / Q000235:genetics / Q000378:metabolism; D016360:Clostridioides difficile / Q000187:drug effects; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004751:Enteritis / Q000139:chemically induced / Q000517:prevention & control*; D004761:Enterocolitis, Pseudomembranous / Q000517:prevention & control; D004768:Enterotoxins / Q000008:administration & dosage / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects; D007082:Ileum / Q000187:drug effects / Q000473:pathology; D051379:Mice; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D000099153:Pentraxins
D000225:Adenine; D000243:Adenosine Deaminase; D058892:Adenosine Deaminase Inhibitors; D001427:Bacterial Toxins; D001593:Benzyl Compounds; D002097:C-Reactive Protein; D016207:Cytokines; D004768:Enterotoxins; D016328:NF-kappa B; D009419:Nerve Tissue Proteins; D052247:Nitric Oxide Synthase Type II; D000099153:Pentraxins; C509055:erythro-(3-nonyl-p-aminobenzyl-adenine); C041348:tcdA protein, Clostridium difficile; C496317:Nos2 protein, mouse