Diesel exhaust nanoparticles: Cellular adaptation in lung epithelial and fibroblast cells - An in vitro study

Diesel exhaust particles (DEnP) represent a major urban air pollutant with known adverse effects on human health, yet detailed cellular interactions at the nanoscale are poorly understood. This study aims to elucidate the cellular responses and adaptation mechanisms of human lung epithelial and fibroblast-like cell lines exposed to Mexican diesel exhaust nanoparticles. Exhaust samples from cold and warm engine emissions were analyzed for polyaromatic hydrocarbons, organic matter, and elemental composition using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, the DEnP nanostructure was scrutinized using 3D topographical image analysis. In vitro assays assessed cell proliferation, adhesion molecule expression (ICAM-1, VCAM-1), and proteins related to endocytosis (clathrin and dynamin) in response to DEnP exposure. SEM and TEM analyses revealed distinct nanoparticle forms and compositions, with significant increases in cell proliferation, endocytosis, and adhesion molecule expression observed, suggesting robust cellular adaptation mechanisms to counteract DEnP-induced stress. The study confirms significant cellular adaptations in response to DEnP, underscoring the need for preventive strategies to mitigate the impacts of exposure. These findings provide a foundation for further investigation into long-term cellular adaptations and their implications for pulmonary health.