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This Article Full Text Full Text (PDF) Supplemental Figures All Versions of this Article: 295/5/L800    most recent 90264.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Ichikawa, T. Articles by Ichinose, M. PubMed PubMed Citation Articles by Ichikawa, T. Articles by Ichinose, M.

Peroxynitrite augments fibroblast-mediated tissue remodeling via myofibroblast differentiation

Third Department of Internal Medicine, Wakayama Medical University, School of Medicine, Kimiidera, Wakayama, Japan

Submitted 7 April 2008 ; accepted in final form 5 September 2008

Irreversible airflow limitation in asthma is associated with airway remodeling in which the differentiation of fibroblasts to myofibroblasts plays a pivotal role. In asthmatic airways, excessive production of reactive nitrogen species (RNS) has been observed. The aim of this study is to evaluate whether peroxynitrite, one of the RNS, can affect the differentiation of fibroblasts to myofibroblasts. Human fetal lung fibroblasts were treated with various concentrations of authentic peroxynitrite or a peroxynitrite donor 3-morpholinosydnonimine hydrochloride (SIN-1), and the expressions of -smooth muscle actin (-SMA) and desmin, markers of myofibroblast differentiation, were evaluated. The releases of transforming growth factor-β₁ (TGF-β₁) and ECM proteins including fibronectin and collagen I were assessed. To clarify the mechanism in this differentiation, the effect of anti-TGF-β antibody or NF-B inhibitors on the -SMA expression and ECM production was assessed. Peroxynitrite and SIN-1 significantly augmented the -SMA expression compared with control in a concentration-dependent manner (P < 0.01 and P < 0.05, respectively). Peroxynitrite significantly increased desmin and TGF-β₁ production (P < 0.01). Peroxynitrite enhanced the translocation of NF-B into the nucleus confirmed by immunocytostaining and immunoblotting. Peroxynitrite-augmented -SMA expression was blocked by NF-B inhibitors, MG132 and caffeic acid phenethyl ester (CAPE), and anti-TGF-β antibody. CAPE completely inhibited the peroxynitrite-augmented TGF-β₁ release. The production of fibronectin and collagen I was significantly increased by peroxynitrite (P < 0.01) and inhibited by anti-TGF-β antibody. These results suggest that RNS can affect the differentiation to myofibroblasts and excessive ECM production via a NF-B-TGF-β₁-dependent pathway.

reactive nitrogen species; airway remodeling; asthma; -smooth muscle actin; nuclear factor-B