Insulin-like Growth Factor Binding Protein 3 in Inflammatory Bowel Disease

Author： Kirman Irena Whelan Richard Jain Suvinit Nielsen Sara Seidelin Jakob Nielsen Ole

ISSN： 0163-2116

Source： Digestive Diseases and Sciences, Vol.50, Iss.4, 2005-04, pp. : 780-784

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Epithelial cell growth regulation has been reported to be altered in inflammatory bowel disease (IBD) patients. The cell growth regulatory factor, insulin-like growth factor binding protein 3 (IGFBP-3), may be partly responsible for this phenomenon. So far, IGFBP-3 levels have been assessed as values of total protein, which is a sum of bioactive intact 43- to 45-kDa protein and its inactive proteolytic cleavage fragments. We aimed to assess the levels of intact IGFBP-3 and its cleaving protease MMP-9 in IBD. Patients with IBD and controls were included. Total plasma IGFBP-3 concentration was measured in ELISA. Western blot analysis, which distinguishes between intact and cleaved IGFBP-3, was performed in order to determine the ratio of intact to total protein; this ratio was used to calculate the concentration of intact IGFBP-3. The profile of plasma proteases was evaluated in zymography and MMP-9 levels were determined in ELISA. The concentration of intact IGFBP-3 was significantly decreased in patients with moderate to severe IBD activity compared to those in remission or controls. Of note, a dramatic depletion of intact IGFBP-3 was found in 7.4% of patients with IBD. Zymography revealed that the dominant gelatinase was the pro-form of MMP-9. However, no differences in MMP-9 levels were noted between those with active disease and controls. The level of intact IGFBP-3 is decreased in IBD patients with moderate to severe disease activity. This decrease may be linked to altered IGFBP-3 production or to increased cleavage by proteases other than MMP-9.