Spot The Difference: Proteasome Composition Differs In Crohn Disease And Ulcerative Colitis

Main Category: GastroIntestinal / Gastroenterology
Also Included In: Crohn's / IBD
Article Date: 28 Nov 2006 - 8:00 PDT


Crohn disease (CD) and ulcerative colitis (UC) are the two most common inflammatory bowel diseases. Both are caused by chronic inflammation in the intestine, although the types of inflammation underlying these disorders differ -- CD is characterized by a Th1 inflammatory response and UC by a Th2 inflammatory response. One potential molecular explanation for the different types of inflammation observed in these two diseases is reported in a study that appears online on November 22 in advance of publication in the December print issue of the Journal of Clinical Investigation. In this study, Ulrich Steinhoff and colleagues at the Max Planck Institute of Infection Biology, Germany, showed that the composition of enzymatic complexes that degrade proteins (known as proteasomes) in the inflamed mucosa of patients with CD differed markedly from the composition of proteasomes in the mucosa of healthy individuals. By contrast, proteasomes in the inflamed mucosa of patients with UC differed only slightly from those in healthy individuals. These differences meant that proteasomes from individuals with CD were more efficient at degrading an inhibitor of NF-kappa-B and processing an NF-kappa-B precursor than proteasomes from individuals with UC, such that the inflammatory mucosa of patients with CD had increased amounts of active NF-kappa-B, an inducer of pro-inflammatory gene expression. This study therefore provides a potential molecular explanation for the different inflammatory responses underlying CD and UC.

TITLE: Proteasome-mediated degradation of I-kappa-B-alpha and processing of p105 in Crohn disease and ulcerative colitis

AUTHOR CONTACT:

Ulrich Steinhoff
Max Planck Institute of Infection Biology, Berlin, Germany.

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JCI table of contents: November 22, 2006

Contact: Karen Honey
Journal of Clinical Investigation

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