Lung injury, inflammation and Akt signaling following inhalation of particulate hexavalent chromium.

Published

Journal Article

Certain particulate hexavalent chromium [Cr(VI)] compounds are human respiratory carcinogens that release genotoxic soluble chromate, and are associated with fibrosis, fibrosarcomas, adenocarcinomas and squamous cell carcinomas of the lung. We postulate that inflammatory processes and mediators may contribute to the etiology of Cr(VI) carcinogenesis, however the immediate (0-24 h) pathologic injury and immune responses after exposure to particulate chromates have not been adequately investigated. Our aim was to determine the nature of the lung injury, inflammatory response, and survival signaling responses following intranasal exposure of BALB/c mice to particulate basic zinc chromate. Factors associated with lung injury, inflammation and survival signaling were measured in airway lavage fluid and in lung tissue. A single chromate exposure induced an acute immune response in the lung, characterized by a rapid and significant increase in IL-6 and GRO-alpha levels, an influx of neutrophils, and a decline in macrophages in lung airways. Histological examination of lung tissue in animals challenged with a single chromate exposure revealed an increase in bronchiolar cell apoptosis and mucosal injury. Furthermore, chromate exposure induced injury and inflammation that progressed to alveolar and interstitial pneumonitis. Finally, a single Cr(VI) challenge resulted in a rapid and persistent increase in the number of airways immunoreactive for phosphorylation of the survival signaling protein Akt, on serine 473. These data illustrate that chromate induces both survival signaling and an inflammatory response in the lung, which we postulate may contribute to early oncogenesis.

Full Text

Duke Authors

Cited Authors

  • Beaver, LM; Stemmy, EJ; Constant, SL; Schwartz, A; Little, LG; Gigley, JP; Chun, G; Sugden, KD; Ceryak, SM; Patierno, SR

Published Date

  • February 15, 2009

Published In

Volume / Issue

  • 235 / 1

Start / End Page

  • 47 - 56

PubMed ID

  • 19109987

Pubmed Central ID

  • 19109987

Electronic International Standard Serial Number (EISSN)

  • 1096-0333

Digital Object Identifier (DOI)

  • 10.1016/j.taap.2008.11.018

Language

  • eng

Conference Location

  • United States