The Increased Expression of Chemokines in the Colonic Mucosa of Patients with Ulcerative Colitis

ABSTRACT

PURPOSE: To better understand the extent to which chemokines participate in the mucosal inflammatory response in patients with ulcerative colitis (UC), we assessed the expression of an array of chemokines in the colonic mucosa of UC patients. METHODS: Colonic mucosal biopsy specimens were obtained from 15 patients with UC and 12 normal controls. Messenger RNA (mRNA) levels for 10 chemokines were quantitated by reverse-transcription PCR using synthetic standard RNAs. The biopsy specimens were also cultured, and secreted chemokines in culture supernatants were assayed by ELISA. RESULTS: The mRNA expression of C-X-C (IL-8, GROalpha, GRObeta, GROgamma, ENA-78, and IP-10) and C-C (MCP-1, MIP-1beta, and RANTES), but not C (lymphotactin) chemokines was significantly higher in the affected mucosa of UC patients than in the unaffected mucosa of UC patients or in the normal mucosa of normal controls. The degree of increased expression was more prominent in the C-X-C than in the C-C chemokines. Further, the secretion of IL-8, GROalpha, ENA-78, and MCP-1 was higher in UC patients than in normal controls. Secretions of MIP-1beta and RANTES also showed a trend toward an increase in UC, but it did not reach statistical significance. CONCLUSION: The increased expression of a variety of chemokines in UC suggest that chemokines may play an important role in the immunopathogenesis of UC.