Original Article: Increased mucosal expression of GATA-3 and STAT-4 in pediatric ulcerative colitis: GATA-3 and STAT-4 in pediatric UC

Background: Serum pro-inflammatory cytokine levels are frequently elevated in the acute phase of pediatric inflammatory bowel disease (IBD). Because the role of pro-inflammatory cytokine in the acute phase of pediatric IBD has not been well investigated, the serum levels of pro-inflammatory cytokines and the expression of Th1 and Th2 signaling molecules in mucosa from the acute phase of pediatric IBD were examined. Methods: Twenty children with ulcerative colitis (UC; mean age, 9.95 +/- 4.10 years) and 12 with Crohn's disease (CD; mean age, 10.0 +/- 4.90 years) were enrolled for the serum cytokine (interleukin [IL]-4, IL-5, IL-6, tumor necrosis factor-alpha, tumor growth factor-beta 1, and interferon-gamma) assay. Expression of T-helper cell 1 (Th1) (T-box expressed in T cells: T-bet and signal transducer and activator of transcription-4: STAT-4) and Th2 (GATA-3 and STAT-6) signaling molecules was examined on real-time polymerase chain reaction using mucosal samples from eight children in the acute phase of UC, eight with CD and eight controls. Results: Significant elevation of serum IL-4 and IL-6 levels was detected at the acute phase of pediatric UC and CD compared with levels at remission (P < 0.05 in each). The mucosal expression of GATA-3 and STAT-4 was significantly enhanced in the acute phase of pediatric UC compared with normal mucosa. No significant difference was observed in the expression of all examined molecules in the acute phase of pediatric CD. Conclusions: IL-4 and its signaling molecule GATA-3, as well as the Th1 signaling molecule STAT-4, are involved in the pathogenesis of acute phase of pediatric UC.