Basic Research
Copyright ©The Author(s) 2005. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 7, 2005; 11(29): 4524-4529
Published online Aug 7, 2005. doi: 10.3748/wjg.v11.i29.4524
Role of interleukin 18 in acute lung inflammation induced by gut ischemia reperfusion
Yong-Jie Yang, Yun Shen, Song-Hua Chen, Xi-Rui Ge
Yong-Jie Yang, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
Yun Shen, Department of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201023, China
Song-Hua Chen, Xi-Rui Ge, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
Author contributions: All authors contributed equally to the work.
Supported by the CAS Pilot Project of Knowledge Innovation Program, No. KSCX 2-3-04-03
Correspondence to: Professor Xi-Rui Ge, Cell Resources Center, Shanghai Institutes for Biological Sciences, CAS, Shanghai 200031, China. gexirui@sibs.ac.cn
Telephone: +86-21-54920407 Fax: +86-21-54920406
Received: December 25, 2004
Revised: January 1, 2005
Accepted: January 5, 2005
Published online: August 7, 2005
Abstract

AIM: To study the changes of endogenous interleukin 18 (IL-18) levels and evaluate the role of IL-18 on lung injury following gut ischemia/reperfusion.

METHODS: A superior mesenteric artery occlusion model was selected for this research. The mice were randomly divided into four groups: Sham operation (sham), ischemia (0.5 h) followed by different times of reperfusion (I/R), and I/R pretreated with exogenous IL-18 (I/R+IL-18) or IL-18 neutralizing antibody (I/R+IL-18Ab) 15 min before ischemia. Serum IL-18 levels were detected by Western blot and ELISA, and the levels of IL-18 in lung tissue were evaluated by immunohistochemical staining. For the study of pulmonary inflammation, the lung myeloperoxidase (MPO) contents and morphological changes were evaluated.

RESULTS: Gut ischemia/reperfusion induced rapid increase of serum IL-18 levels, peaked at 1 h after reperfusion and then declined. The levels of IL-18 in lung tissue were gradually enhanced as the progress of reperfusion. Compared with I/R group, exogenous administration of IL-18 (I/R+IL-18) further remarkably enhanced the pulmonary MPO activity and inflammatory cell infiltration, and in I/R+IL-18Ab group, the content of MPO were significantly reduced and lung inflammation was also decreased.

CONCLUSION: Gut ischemia/reperfusion induces the increase of IL-18 expression, which may make IL-18 act as an important proinflammatory cytokine and contribute to gut ischemia/reperfusion-induced lung inflammation.

Keywords: IL-18; Ischemia; Reperfusion; Inflammation