Elevated expression of NOS mRNA and protein in coeliac disease

Background: The role of nitric oxide synthase (NOS) in the pathophysiology of coeliae disease (CD) was investigated. Methods: We examined mRNA (reverse transcription multiplex polymerase chain reaction) and protein expression (Western blotting) of i,e and nNOS in enterocytes isolated from the duodenum of patients with untreated CD (n =22) and iron deficiency anaemia (IDA, n = 22). Expression of IL1 beta and TNF alpha two pivotal "NOS-controlling" cytokines, was also studied. Results: Enterocytes from both patient groups were negative for eNOS and TNFa message but positive for n and iNOS. nNOS gene expression was not statistically different between groups (158.38 +/- 29.11% vs. 114.95 +/- 24.17%, IDA vs. CD, p =0.07, Mann-Whitney U). iNOS expression was higher in patients with CD when compared to patients with IDA (96.95 +/- 17.82% vs. 48.76 +/- 8.07%, p < 0.006). Low levels of lL1 beta mRNA (15.66 +/- 3.70%) were detected in nine samples-all of these samples were isolated from patients with CD representing a positive result in 40% of coeliac patients. In support of these observations, patients with CD expressed more iNOS protein than those with IDA (159.7 +/- 14.9% vs. 69.8 +/- 20%, p < 0.05). Conclusion: These results suggest that iNOS could be an important mediator in coeliac disease. Expression of this regulatory protein may be under the control of IL1 beta. (c) 2005 Elsevier B.V. All rights reserved.