Distinct gene expression of osteopontin in patients with ulcerative colitis

Background. Ulcerative colitis (UC) is a multifactorial disorder of unknown etiology. Few studies have applied genome-wide gene expression analysis in colon tissue samples of UC. We report the analysis of mucosal gene expression in UC and noninflamed control specimens. Materials and methods. This study included 7 UC patients who received a total colectomy because of severe total colitis. Normal control colon tissues were obtained at least 10 cm from the area of pathology in 3 colon cancer patients. Ten colonic tissue samples (7 UC and 3 normal control samples) were subjected to high-density oligonucleotide array analysis. To compare differences in the level of gene expression between UC and control samples, Mann-Whitney U-test was used, with significance set at P < 0.05. Results. Twenty-five genes had a 3.0similar to23.4-fold higher mRNA expression in UC samples compared with normal samples, whereas three genes had a 3.0 similar to 3.4-fold lower expression in UC samples compared with normal samples. Two genes showing more than a 10-fold increase expression in UC samples were a macrophage metalloelastase (L23808) and a osteopontin (AF052124). It has been said that macrophage metalloelastase is related to ulcer formation of the intestine, whereas osteopontin plays an important role in the pathogenesis of systemic lupus erythematosus and rheumatoid arthritis. Conclusion. Our present study supports the previous report that macrophage metalloelastase is related to ulcer formation of UC, and it also indicates the possibility that osteopontin plays an important role in the pathogenesis of UC via increased immune activity. (C) 2003 Elsevier Inc. All rights reserved.