Combined toxic effects of CBNPs and Pb on rat alveolar macrophage apoptosis and autophagy flux

Carbon black (CB) and heavy metals are the main components of Particulate Matter (PM). Although the individual toxicities of CB and heavy metals have been extensively studied, the combined toxicity is much less understood. In this study, we choose the nano carbon black (CBNPs) and Pb 2+ to simulate fine particles in the atmosphere and study the combined toxic effect on rat alveolar macrophages. The data showed that CBNPs could adsorb Pb 2+ to form CBNPs-Pb 2+ complex and displayed an altered physical properties by particle characterization. CBNPs-Pb 2+ synergistically induced rat alveolar macrophages apoptosis and blocked autophagy flux compared with CBNPs and Pb 2+ individually. Consistent with this, CBNPs-Pb 2+ could impair the mitochondrial membrane potential (MMP), activate apoptotic signaling pathways, inhibit lysosomal function.