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Mediators of Inflammation
Volume 2011 (2011), Article ID 745340, 9 pages
http://dx.doi.org/10.1155/2011/745340
Research Article

Novel Biphasic Role of LipoxinA4 on Expression of Cyclooxygenase-2 in Lipopolysaccharide-Stimulated Lung Fibroblasts

1Department of Anaesthesia, Second Affiliated Hospital of WenZhou Medical College, Zhejiang 325003, China
2Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, Hubei Province 430030, China
3Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
4Academic Department of Critical Care, Resuscitation, Anaesthesia, and Pain, Heart of England NHS Foundation Trust, Birmingham B9 5SS, UK

Received 15 February 2011; Accepted 3 May 2011

Academic Editor: Donna-Marie McCafferty

Copyright © 2011 Shengxing Zheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Fibroblasts are important to host defence and immunity, can also as initiators of inflammation as well. As the endogenous “braking signal”, Lipoxins can regulate anti-inflammation and the resolution of inflammation. We investigated the effect of lipoxinA4 on the expression of cyclooxygenase-2 in lipopolysaccharide-stimulated lung fibroblasts. We demonstrated that the expression of cyclooxygenase-2 protein was significantly increased and peaked initially at 6 hours, with a second increase, with maximal levels occurring 24 hours after lipopolysaccharide challenge. ProstaglandinE2 levels also peaked at 6 hours, and prostaglandinD2 levels were increased at both 6 and 24 hours. Exogenous lipoxinA4 inhibited the first peak of cyclooxygenase-2 expression as well as the production of prostaglandinE2 induced by lipopolysaccharide in a dose-dependent manner. In contrast, exogenous lipoxinA4 increased the second peak of cyclooxygenase-2 expression as well as the production of prostaglandinD2 induced by lipopolysaccharide in a dose-dependent manner. LipoxinA4 receptor mRNA expression was markedly stimulated by lipopolysaccharide but inhibited by lipoxinA4. We present evidence for a novel biphasic role of lipoxinA4 on the expression of cyclooxygenase-2 in lipopolysaccharide-stimulated lung fibroblasts, whereby LXA4 has an anti-inflammatory and proresolving activity in lung fibroblasts following LPS stimulation.