Fig. 2

NAO and Ceramic brake-wear PM induce the greatest oxidative stress. ATII cells were exposed to 8, 16, and 32 µg/cm² of the 5 different vehicle-derived PM types for 24 h. A LDH release was measured, with higher LDH release indicating higher cytotoxicity; LDH release was determined using a CytoTox 96^® Non-Radioactive Cytotoxicity Assay kit, n = 3. B ROS generation was assessed in ATII cells via oxidation of H₂-DCF into the fluorescent DCF after 24 h of exposure to PM; tert-Butyl hydroperoxide (TBHP) was used as a positive control for ROS induction, n = 5. C ATII Haem Oxygenase-1 (HMOX1) expression was determined using RT-qPCR after exposure to 8 µg/cm² of the 5 different PM types, for 2, 6 and 24 h, n = 3 for 2 h exposure. n = 5 for 6 and 24 h exposure. D ATII cell Glutamate-Cysteine Ligase Modifier Subunit (GCLM) expression was determined using RT-qPCR after exposure to 8 µg/cm² of the 5 different PM types, for 2, 6 and 24 h, n = 3. Data was represented as mean + SEM, and a RM one-way ANOVA test was used with a Dunnett’s post-hoc test to determine significance compared to the control. * = p ≤ 0.05, ** = p ≤ 0.01, **** = p ≤ 0.0001