Carbon Black Nanoparticles Promote Endothelial Activation and Lipid Accumulation in Macrophages Independently of Intracellular ROS Production

Abstract

Exposure to nanoparticles (NPs) may cause vascular effects including endothelial dysfunction and foam cell formation, with oxidative stress and inflammation as supposed central mechanisms. We investigated oxidative stress, endothelial dysfunction and lipid accumulation caused by nano-sized carbon black (CB) exposure in cultured human umbilical vein endothelial cells (HUVECs), THP-1 (monocytes) and THP-1 derived macrophages (THP-1a). The proliferation of HUVECs or co-cultures of HUVECs and THP-1 cells were unaffected by CB exposure, whereas there was increased cytotoxicity, assessed by the LDH and WST-1 assays, especially in THP-1 and THP-1a cells. The CB exposure decreased the glutathione (GSH) content in THP-1 and THP-1a cells, whereas GSH was increased in HUVECs. The reactive oxygen species (ROS) production was increased in all cell types after CB exposure. A reduction of the intracellular GSH concentration by buthionine sulfoximine (BSO) pre-treatment further increased the CB-induced ROS production in THP-1 cells and HUVECs. The expression of adhesion molecules ICAM-1 and VCAM-1, but not adhesion of THP-1 to HUVECs or culture dishes, was elevated by CB exposure, whereas these effects were unaffected by BSO pre-treatment. qRT-PCR showed increased VCAM1 expression, but no change in GCLM and HMOX1 expression in CB-exposed HUVECs. Pre-exposure to CB induced lipid accumulation in THP-1a cells, which was not affected by the presence of the antioxidant N-acetylcysteine. In addition, the concentrations of CB to induce lipid accumulation were lower than the concentrations to promote intracellular ROS production in THP-1a cells. In conclusion, exposure to nano-sized CB induced endothelial dysfunction and foam cell formation, which was not dependent on intracellular ROS production.

Carbon nanoparticle induced cytotoxicity in human mesenchymal stem cells through upregulation of TNF3, NFKBIA and BCL2L1 genes

“…Additionally, our cell viability results suggest that CNPs significantly reduce cell viability in hMSCs in a dose-and timedependent manner. Our results are consistent with previous studies, which have demonstrated that nanoparticles (carbon black, gold, silver, silica, iron oxide) exhibit dose-, time-and sizedependent cytotoxicity in various cell lines (Coradeghini et al, 2013;Gliga et al, 2014;Yang et al, 2015;Napierska et al, 2009;Kim et al, 2012;Sahu et al, 2014;Cao et al, 2014).…”

“…Nanotoxicologists are beginning to evaluate the potential risks of engineered nanoparticles on health and the environment to overcome the insufficient toxicological information and current regulatory regimes in an effort to ensure the safe development and use of nanomaterials in commercial products (Aitken et al, 2009). Numerous studies have demonstrated that engineered nanoparticles exhibited toxic effects on various mammalian cell lines and animal models (Barlow et al, 2005;Vesterdal et al, 2012;Danielsen et al, 2008;Folkmann et al, 2012;Card et al, 2008;Kroll et al, 2011;Castranova, 2011). Moreover, engineered nanoparticles exhibited cytotoxic effects based on their size, shape, aggregation state, surface charge and surface area (Albanese et al, 2012;Powers et al, 2007).…”

Automobile diesel exhaust particles induce lipid droplet formation in macrophages in vitro

“…The formation of lipid droplets was also measured by fluorescence microscopy as previously described (Cao et al, 2014b). Briefly, A-DEP exposed THP-1 macrophages seeded on pre-coated 8-well microscopy chamber slides were washed twice with PBS and fixed by 4% paraformaldehyde for 30 min at room temperature.…”

“…The green fluorescence was quantified using a Leica microscope with 40× magnification in 5 randomly selected areas (n = 5), with each sample captured as a z-stack. After 3D deconvolution and 3D projection, the fluorescent areas in each independent area were analyzed by ImageJ and normalized by the number of cells (Cao et al, 2014b).…”

Thermoresponsive Polymers with Lower Critical Solution Temperature‐ or Upper Critical Solution Temperature‐Type Phase Behaviour Do Not Induce Toxicity to Human Endothelial Cells

“…4), which supports the results of LDH assay. In a previous report, it was shown that carbon black nanoparticles significantly decreased mitochondrial viability in HUVECs, THP-1 monocytes and THP-1 macrophages, whereas LDH release was only significantly elevated in nanoparticle-exposed THP-1 monocytes [20]. Thus, it Fig.…”