Acute exposure to PM2.5 triggers lung inflammatory response and apoptosis in rat.

Severe haze events, especially with high concentration of fine particulate matter (PM2.5), are frequent in China, which have gained increasing attention among public. The purpose of our study was explored the toxic effects and potential damage mechanisms about PM2.5 acute exposure. Here, the diverse dosages of PM2.5 were used to treat SD rats and human bronchial epithelial cell (BEAS-2B) for 24 h, and then the bioassays were performed at the end of exposure. The results show that acute exposure to diverse dosages of PM2.5 could trigger the inflammatory response and apoptosis. The severely oxidative stress may contribute to the apoptosis. Also, the activation of Nrf2-ARE pathway was an important compensatory process of antioxidant damage during the early stage of acute exposure to PM2.5. Furthermore, the HO-1 was suppression by siRNA that promoted cell apoptosis triggered by PM2.5. In other words, enhancing the expression of HO-1 may mitigate the cell apoptosis caused by acute exposure to PM2.5. In summary, our findings present the first time that prevent or mitigate the damage triggered by PM2.5 through antioxidant approaches was a promising strategy.