Expression of JP-8-induced inflammatory genes in AEII cells is mediated by NF-kappaB and PARP-1.

Lung epithelial cells are critical in the regulation of airway inflammation in response to environmental pollutants. Altered activation of NF-kappaB is associated with expression of several proinflammatory factors in respiratory epithelial cells in response to an insult. Here we show that a low threshold dose (8 microg/ml) of the jet fuel JP-8 induces in a rat alveolar epithelial cell line (RLE-6TN) a prolonged activation of NF-kappaB as well as the increased expression of the proinflammatory cytokines TNF-alpha and IL-8, which are regulated by NF-kappaB. The up-regulation of IL-6 mRNA in cells exposed to JP-8 appears to be a reaction of RLE-6TN cells to reduce the enhancement of proinflammatory mediators in response to the fuel. Moreover, lung tissues from rats exposed to occupational levels of JP-8 by nasal aerosol also showed dysregulated expression of TNF-alpha, IL-8, and IL-6, confirming the in vitro data. The poly(ADP-ribosyl)ation of PARP-1, a coactivator of NF-kappaB, was coincident with the prolonged activation of NF-kappaB during JP-8 treatment. These results evidenced that a persistent exposure of the airway epithelium to aromatic hydrocarbons may have deleterious effects on pulmonary function.