Relevance of DPP IV/CD26 among the Gut-brain Axis during Experimental Colitis

Inflammatory bowel diseases (IBD) represent a group of chronic conditions of the gastrointestinal tract of unknown etiology. Latest knowledge accentuates the bidirectional connection between the central and enteric nervous systems. An important role of peptidases has been proposed in maintaining the homeostasis in the gut. One of them is dipeptidil-peptidase IV (DPP IV/CD26), a multifunctional glycoprotein found in both soluble and membrane-bound form in living organisms. In order to evaluate the relevance of DPP IV/CD26 among the gut-brain axis, a TNBS (Crohn-like) model of colitis has been induced in CD26 deficient and wild type mice. Results of this study showed that CD26 deficient mice show specificity in histological damage compared to wild type mice. A decreased DPP IV/CD26 activity was found in serum, colon and brain in wild type mice with colitis, while CD26 protein expression was increased in colon of those mice. DPP IV/CD26-like activity was decreased only in colon of CD26 deficient mice. Changes occurring during inflammatory processes in colon reflected on investigated parameters in brain. Therefore, our results indicate the importance of the gut-brain axis in the pathogenesis of IBD. (doi: 10.5562/cca1813)