Air–Liquid Interface (ALI) Exposure of Human Bronchial Epithelial Cells to Whole Gasoline Engine Exhaust Disrupts Autophagy and Proinflammatory Responses

Gasoline engine exhaust (GEE) has been reported to contribute to the pathogenesis of pulmonary diseases. Autophagy, proinflammatory cytokines, and the NF-κB pathway core protein may play roles in the development of lung diseases caused by GEE. However, little is known about the possible toxic effects. Herein, we aimed to examine the crosstalk between GEE and the expression levels of autophagy-associated proteins (microtubule-associated proteins 1A/1B light chain 3A (LC3I/II)), proinflammatory cytokine genes (including <i>interleukin-1β</i> (<i>IL-1β</i>), <i>IL-6</i> and <i>IL-8</i>), and the NF-kB pathway core protein p65 by conducting an air-liquid interface exposure study in BEAS-2B cells. A CCK-8 assay was conducted to explore the viability of BEAS-2B cells exposed to GEE and 3-methyladenine (3-MA). The protein expression levels of LC3I/II and p65 were detected using Western blotting. The gene expression levels of <i>LC3B</i>, <i>IL-1β</i>, <i>IL-6</i>, and <i>IL-8</i> were measured using real-time PCR. We found that GEE decreased the viability of BEAS-2B cells in a dose-dependent manner, whereas 10%GEE exposure and 2.5 mM 3-MA had no significant effect. As the dose of GEE increased, LC3I/II protein and gene expression levels, proinflammatory cytokine gene expression levels, and p65 protein expression levels showed varying degrees of changes. Additionally, after treatment with 3-MA, these indicators tended to decrease, but only the gene expression levels of proinflammatory cytokines were statistically significant. These results suggest that GEE could interfere with autophagy and induce an inflammatory response in human bronchial epithelial cells, and that modest changes in autophagy could significantly alleviate this response, thereby providing new insights for the understanding of lung injury caused by GEE.