Table of Contents
Journal of Allergy
Volume 2012 (2012), Article ID 372384, 8 pages
http://dx.doi.org/10.1155/2012/372384
Review Article

Role of the Arylhydrocarbon Receptor (AhR) in the Pathology of Asthma and COPD

1Department of Dermatology, Graduate School of Medical Sciences, Kyushu University School of Medicine, 3-1-1, Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan
2Department of Clinical and Laboratory Medicine, Akita University School of Medicine, Akila 010-8502, Japan
3Research and Clinical Center for Yusho and Dioxin, Kyushu University Hospital, Fukuoka 812-8582, Japan

Received 17 September 2011; Accepted 18 October 2011

Academic Editor: Brian Oliver

Copyright © 2012 Takahito Chiba 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

The dioxins and dioxin-like compounds in cigarette smoke and environmental pollutants modulate immunological responses. These environmental toxicants are known to cause lung cancer but have also recently been implicated in allergic and inflammatory diseases such as bronchitis, asthma, and chronic obstructive pulmonary disease (COPD). In a novel pathway of this response, the activation of a nuclear receptor, arylhydrocarbon receptor (AhR), mediates the effects of these toxins through the arachidonic acid cascade, cell differentiation, cell-cell adhesion interactions, cytokine expression, and mucin production that are implicated in the pathogenesis and exacerbation of asthma/COPD. We have previously reported that human bronchial epithelial cells express AhR, and AhR activation induces mucin production through reactive oxygen species. This review discusses the role of AhR in asthma and COPD, focusing in particular on inflammatory and resident cells in the lung. We describe the important impact that AhR activation may have on the inflammation phase in the pathology of asthma and COPD. In addition, crosstalk of AhR signaling with other ligand-activated transcription factors such as peroxisome proliferator-activated receptors (PPARs) has been well documented.