Induction of pro-inflammatory signals by 1-nitropyrene in cultured BEAS-2B cells

Nitropyrene (1-NP) is classified as Group 2B carcinogen and is one of the main components of diesel exhaust particles (DEP), which are generated from incomplete combustion of automobile engines to cause human cancer or inflammatory diseases. Although many reports on the mutagenesis or carcinogenesis of 1-NP have been released, non-carcinogenic toxicities of 1-NP have not been widely studied. In this study, induction of pro-inflammatory signals by 1-NP was investigated using cultured human bronchial epithelial cells, BEAS-2B. By using microarray analysis and RT-PCR technique, it was found that 1-NP induced the expression of genes related to the pro-inflammatory responses such as pentaxin, IL-1beta, IL-6, IL-8, C-X-C motif ligand 2 (CXCL2), and TNF-alpha. 1-NP was also found to induce ROS generation and intracellular GSH decrease. It suggested that 1-NP may be a pivotal component of DEP to cause inflammatory diseases.