Figure 4. Scavenger receptors do not mediate diesel exhaust particle (DEP)-induced H₂O₂ production in microglia.

HAPI microglia cells were pretreated with the scavenger receptor inhibitor fucoidan (100µg/ml) for 30 min followed by DEP (100 µg/ml) DEP extract (eDEP, from 100 µg/ml DEP), and carbon black (ufCB, 100 µg/ml) treatment. The production of hydrogen peroxide (H₂O₂) was measured by the catalase-inhibitable fluorescence at 3 hr post-treatment. Fucoidan failed to affect DEP, eDEP, or ufCB -induced H₂O₂ production. Samples were run in triplicates and the data are the result of 3 independent experiments (n=3). Results are expressed as percent of control and are the mean ± SEM. The raw data (fluorescence) for the control treatment range from 601 –986 across experimental replicates. An asterisks indicates a significant difference from control (2 Way ANOVA, p<0.05; fucoidin treatment main effect, p<0.05; DEP treatment main effect, p<0.05).