HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 292/2/L422    most recent 00204.2006v1 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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Cao, D. Articles by Samet, J. M. Search for Related Content PubMed PubMed Citation Articles by Cao, D. Articles by Samet, J. M.

Diesel exhaust particulate-induced activation of Stat3 requires activities of EGFR and Src in airway epithelial cells

¹Center for Environmental Medicine, Asthma and Lung Biology, ²Curriculum in Toxicology, and ³Department of Pharmacology, University of North Carolina, Chapel Hill; and ⁴Human Studies Division, United States Environmental Protection Agency, Research Triangle Park, North Carolina

Submitted 6 June 2006 ; accepted in final form 4 October 2006

In vivo exposure to diesel exhaust particles (DEP) elicits acute inflammatory responses in the lung characterized by inflammatory cell influx and elevated expression of mediators such as cytokines and chemokines. Signal transducers and activators of transcription (STAT) proteins are a family of cytoplasmic transcription factors that are key transducers of signaling in response to cytokine and growth factor stimulation. One member of the STAT family, Stat3, has been implicated as a regulator of inflammation but has not been studied in regard to DEP exposure. The results of this study show that DEP induces Stat3 phosphorylation as early as 1 h following stimulation and that phosphorylated Stat3 translocates into the nucleus. Inhibition of epidermal growth factor receptor (EGFR) and Src activities by the inhibitors PD-153035 and PP2, respectively, abolished the activation of Stat3 by DEP, suggesting that Stat3 activation by DEP requires EGFR and Src kinase activation. The present study suggests that oxidative stress induced by DEP may play a critical role in activating EGFR signaling, as evidenced by the fact that pretreatment with antioxidant prevented the activation of EGFR and Stat3. These findings demonstrate that DEP inhalation can activate proinflammatory Stat3 signaling in vitro.

signal transducer and activator of transcription 3; epidermal growth factor receptor; reactive oxygen species; human airway epithelial cells; diesel exhaust particles