Identification of early biomarkers of inflammation produced by keratinocytes exposed to jet fuels jet A, JP-8, and JP-8(100)

Abstract

The purpose of this study was to identify biomarkers of inflammation in normal human epidermal keratinocytes (NHEK) exposed to three jet fuel mixtures, Jet A, JP8, and JP8(100). NHEK were treated over 24 hours with 0.1% jet fuels, and mRNA production and protein release of two proinflammatory cytokines, IL‐8 and TNF‐α, were determined. Using an enzyme‐linked immunosorbent assay (ELISA), NHEK were found to release both TNF‐α and IL‐8 in response to exposure to all three jet fuels. IL‐8 release was noted within 8 hours and continued to rise through 24 hours compared to controls. Maximal levels of TNF‐α release were seen at 4 hours and decreased in a time‐dependent manner, although these levels remained above control levels at all time points assayed. mRNA for IL‐8 was elevated 4 hours following exposure to the fuels, which was detected via a quantitative competitive reverse transcriptase‐polymerase chain reaction (RT‐PCR). mRNA for TNF‐α was detected at all time points assayed but was not quantified. These results demonstrate that jet fuels induce the production and release of proinflammatory cytokines in NHEK and thus create the potential for chronic inflammation, which may contribute to the development or progression of disease states in the skin. © 2000 John Wiley & Sons, Inc. J Biochem Toxicol 14:231–237, 2000