Abstract
BackgroundExposure to toluene diisocyanate (TDI) is a significant pathogenic factor for asthma. We previously reported that receptor for advanced glycation end products (RAGE) plays a key role in TDI-induced asthma; however, the mechanism is not clear. Epigenetic alterations of histone deacetylase (HDAC) are associated with allergic asthma. However, its effect in TDI-induced asthma is not known. The purpose of this study was to determine the role of RAGE and HDAC1 in the regulation of airway inflammation using a TDI-induced asthma model.MethodsBALB/c mice were sensitized, and challenged by TDI to establish murine asthma models. FPS-ZM1 (RAGE inhibitor), JNJ-26482585 and romidepsin (HDAC inhibitor) were given intraperitoneally before each challenge. The human bronchial epithelial cell line 16HBE was stimulated by TDI-human serum albumin (TDI-HSA) in vitro. RAGE knockdown cells were constructed and evaluated, and MK2006 (AKT inhibitor) was used in in vitro experiments.ResultsIn the TDI-induced asthmatic mice, airway reactivity, the level of Th2 cytokines in lymph supernatant, IgE, airway inflammation, and goblet cell metaplasia were all significantly increased. The increases were suppressed by FPS-ZM1, JNJ-26482585, and romidepsin. The expression of HDAC1, RAGE, and p-AKT/t-AKT was also upregulated in TDI-induced asthmatic mice, and the expressions were attenuated by FPS-ZM1. Knockdown of RAGE attenuated the upregulation of HDAC1 and phospho-AKT (p-AKT) in 16HBE cells stimulated by TDI-HSA. Treatment with the AKT inhibitor MK2006 suppressed TDI-induced HDAC1 expression. ConclusionRAGE mediates airway inflammation in a TDI-induced murine asthma model, partly via the HDAC1 pathway. Key words: Toluene diisocyanate, asthma, histone deacetylase 1, advanced glycosylation end product receptor
Occupational asthma risk from exposures to toluene diisocyanate: A review and risk assessment
