Increased expression and activation of IL-12-induced Stat4 signaling in the mucosa of ulcerative colitis patients.
Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic inflammatory diseases with unsolved pathogenesis. Imbalanced Th1/Th2 may play a role in the sustained inflammation of IBD. In China, CD is rare but the incidence of UC has been rising steadily in the last two decades. We investigated the expression of IL-12 (p40) and IFN-gamma, and the activational state of Stat4 signaling in mucosal tissues at the site of disease from 30 active UC patients in comparison with 30 healthy controls. RT-PCR analyses revealed increased mRNA expression of IL-12 (p40) but not IFN-gamma in UC patients. Western blot analyses discovered, for the first time, increased levels of constitutive Stat4 in the cytoplasm and phosphorylated Stat4 in the nucleus of mucosal cells from UC patients. We conclude that a heightened, perhaps persistent, activational state of IL-12/Stat4, and/or IL-23/Stat4 signaling may be present in active Chinese UC patients, and possibly involved in chronic inflammation in UC.
Department of Gastroenterology, Beijing Chaoyang Hospital, The Capital University of Medical Sciences, Beijing 100020, China.
Yan Hua
YH
Pang
Chang Qing
CQ
Zheng
Xian Zi
XZ
Yang
Wen Jie
WJ
Zhang
D000328:Adult; D000368:Aged; D003093:Colitis, Ulcerative / Q000145:classification / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D053762:Interleukin-12 Subunit p40 / Q000096:biosynthesis* / Q000378:metabolism* / Q000502:physiology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D050797:STAT4 Transcription Factor / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology*
D053762:Interleukin-12 Subunit p40; D050797:STAT4 Transcription Factor