The Oxidation Catalytic Converter Reduces the Inhibitory Activity of Soluble Organic Fractions of Diesel Particles on Intercellular Communication

Abstract

The genotoxicity of diesel particles has been widely documented, and their tumor promoting effect has been reported recently using the gap junction intercellular communication (GJIC) assay. In our study, the ability of soluble organic fractions (SOF) of diesel particles emitted from cars equipped (WC) or not (WoutC) with the oxidation catalytic converter (OCC) and of particle SOF from an outdoor high polluted place (OHPP) to inhibit GJIC has been evaluated with two cell lines: a rat liver epithelial cell line (REL cells) and a rat pulmonary alveolar type II cell line (3T cells). With both cell lines, our results demonstrate that GJIC is strongly inhibited by WoutC, whereas it is much less reduced by WC ones: for REL cells, the activity of WC particles is 1/4 of the one of WoutC. Also, we show that the inhibition induced by WoutC is associated with a change in the GJ protein localization. Our results clearly show the effectiveness of the OCC technology in reducing both the tumor promoting activity and the genotoxicity of diesel particle SOF.