Quantification of chemokine and chemokine receptor gene expression in duodenal mucosa of dogs with inflammatory bowel disease

Although chemokines and their receptors play an integral role in the regulation of the immune response, there is very little information about their involvement in canine inflammatory bowel disease (IBD). The objective of this study was to evaluate the mRNA expression of 9 selected chemokines and 6 chemokine receptors by real-time reverse transcription PCR in the duodenal mucosa from 21 dogs with IBD and 25 control dogs. The transcription levels of monocyte chemotactic protein-1 (MCP-1)/CCL2, macrophage inflammatory protein-3 alpha (MIP-3α)/CCL20, thymus-expressed chemokine (TECK)/CCL25, mucosae-associated epithelial chemokine (MEC)/CCL28 and IL-8/CXCL8 mRNA in IBD dogs were significantly higher than the corresponding levels in control dogs, but there was no significant difference in the mRNA levels of the chemokine receptors between the 2 groups. In addition, the CCL2 and CXCL8 mRNA levels were significantly higher in the high clinical severity score group than in the low clinical severity score group. However, there was no correlation between chemokine or chemokine receptor mRNA expressions and histopathological severity score. The present results suggest that several chemokines may play important roles in the pathogenesis of canine IBD.