Abstracts (complete list) - Wissenschaft Online

Ulrich Steinhoff, Alexander Visekruna, Anjo Kroesen
The proteasome controls NF-κB-mediated inflammation in IBD
patients
Proteasomes are the central proteolytic machinery of cells involved in degradation of
proteins and generation of MHC class I epitopes. Additionally they play a central role in
regulation of inflammatory processes mediated by NF-κB. We analyzed the structure
and function of 20S proteasomes in normal and inflamed intestinal tissues from Crohn’s
disease (CD)and ulcerative colitis (UC) patients.
Our results show tissue-specific differences in proteasome composition as previously
reported in mice.
However, we found marked differences in proteasome composition between CD and UC
patients. Inflammation affected the proteasome composition only in CD patients with
strong expression of immunosubunits in the inflamed tissues.
Immunoproteasomes isolated from CD patients degraded IκBα and processed p105
much faster than constitutive proteasomes from UC patients. Immunohistochemical
analysis confirmed that the amount of activated NF-κB correlated with the expression of
immunoprotesasomes.
This demonstrates that the mechanism of inflammation differs between UC and CD
patients and that proteasomes are crucially involved in Th1-mediated inflammation.