Transcriptomic Changes in Human Pulmonary Fibroblasts Following Microplastics Exposure

To assess the cellular effects of polystyrene (PS) micro- and nanoparticles, human pulmonary fibroblasts (HPFs) were exposed to spherical PS particles of two diameters (100 nm and 1 µm) across multiple concentrations. For 100 nm particles, the concentrations were 0.1 g/L (A), 0.01 g/L (B), and 0.001 g/L (C); for 1 µm particles, 0.1 g/L (A), 0.05 g/L (D), 0.01 g/L (B), and 0.001 g/L (C) were tested. In summary, our data show that both particle size and concentration critically influence the cellular response to microplastics. At low concentrations (0.001 g/L), smaller particles (100 nm) induced transcriptional activation of mitochondrial and biosynthetic genes, suggesting early metabolic adaptation. In contrast, high concentrations (0.1 g/L), particularly of larger particles (1 µm), led to suppression of metabolic, mitochondrial, and proteostatic pathways, indicating functional impairment and potential cellular stress.