Modulation of airway remodeling and airway inflammation by peroxisome proliferator-activated receptor gamma in a murine model of toluene diisocyanate-induced asthma.

Abstract

Toluene diisocyanate (TDI) is a leading cause of occupational asthma. Although considerable controversy remains regarding its pathogenesis, TDI-induced asthma is an inflammatory disease of the airways characterized by airway remodeling. Peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to play a critical role in the control of airway inflammatory responses. However, no data are available on the role of PPARgamma in TDI-induced asthma. We have used a mouse model for TDI-induced asthma to determine the effect of PPARgamma agonist, rosiglitazone, or pioglitazone, and PPARgamma on TDI-induced bronchial inflammation and airway remodeling. This study with the TDI-induced model of asthma revealed the following typical pathophysiological features: increased numbers of inflammatory cells of the airways, airway hyperresponsiveness, increased levels of Th2 cytokines (IL-4, IL-5, and IL-13), adhesion molecules (ICAM-1 and VCAM-1), chemokines (RANTES and eotaxin), TGF-beta1, and NF-kappaB in nuclear protein extracts. In addition, the mice exposed to TDI developed features of airway remodeling, including thickening of the peribronchial smooth muscle layer, subepithelial collagen deposition, and increased airway mucus production. Administration of PPARgamma agonists or adenovirus carrying PPARgamma2 cDNA reduced the pathophysiological symptoms of asthma and decreased the increased levels of Th2 cytokines, adhesion molecules, chemokines, TGF-beta1, and NF-kappaB in nuclear protein extracts after TDI inhalation. In addition, inhibition of NF-kappaB activation decreased the increased levels of Th2 cytokines, adhesion molecules, chemokines, and TGF-beta1 after TDI inhalation. These findings demonstrate a protective role of PPARgamma in the pathogenesis of the TDI-induced asthma phenotype.

• Authors: Kyung Sun Lee, Seoung Ju Park, So Ri Kim, Kyung Hoon Min, Sun Mi Jin, Hern Ku Lee, Yong Chul Lee
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 177 Issue 8 Pg. 5248-57 (Oct 15 2006) ISSN: 0022-1767 [Print] United States
• PMID: 17015710 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cell Adhesion Molecules
• Cytokines
• NF-kappa B
• PPAR gamma
• Transforming Growth Factor beta1
• Toluene 2,4-Diisocyanate

Topics

• Animals
• Asthma (chemically induced, immunology, pathology)
• Cell Adhesion Molecules (analysis)
• Cytokines (analysis)
• Disease Models, Animal
• Inflammation (pathology)
• Mice
• NF-kappa B (analysis)
• PPAR gamma (agonists, physiology)
• Respiratory System (pathology)
• Th2 Cells
• Toluene 2,4-Diisocyanate (adverse effects)
• Transforming Growth Factor beta1 (analysis)