The composition of diesel exhaust particles affects differently the cell signaling and cytoskeleton in bronchial epithelial cells

Backgroung: Diesel exhaust particles (DEP) have a major contribution of the ultrafine particles to the air pollution. Hydrocarbons and metals adsorbed on surface of DEP cause physiological and molecular disturbances in cells of the respiratory system. Methods : We used four samples of DEP with different compositions after treatment: 1) Acid extraction (HNO 3 65%) to remove mainly metals (DEP/NA); 2) solvents: a) methanol to remove organic composed with high and medium polarity (DEP/MET), b) hexane to remove organic compound with low polarity (DEP/MET) and DEP crude to study MAPKs activation (ERK and JNK) and cell rheology (OMTC technical). The cells were exposed to 100µg/mL of DEPs fractions in air-liquid system during 15, 30 and 60 minutes. The MAPKs JNK and ERK are activated simultaneously in DEP crude and DEP/MET. Results: In DEP/NA and DEP/HEX only JNK was activated. The compositions of DEP/MET are mainly iron, cupper and cadmium and Benz[a]anthracene and pyrene. DEP/NA and DEP/HEX had a reduction of 50% of PHAs concentration, but the copper and cadmium appear to be the most available causing JNK activation, significant (p=0.03) reduction in fiber coherence and increased viscoelasticity at short time (15 minutes). Conclusion: The adverse findings detected after exposure to DEPs fractions represents the toxic potential of diesel compounds and could be consequence of using bad fuel with low-technology engines. In addition the activation of these MAPKs is a major indication that the chemical composition of the DEP around the world can influence the onset of or worsening of respiratory diseases via MAPKs activation.