Anti-inflammatory and antioxidant effects of cerium oxide nanoparticles in human endothelial cells

Abstract

Purpose: The vascular endothelium, by virtue of its strategic location and important role in cardiovascular disease, represents an important target for drug or gene therapy. Studies have focused on targeting the endothelium with nanoparticles, as therapeutic agents. Cerium oxide nanoparticles (nanoceria) have attracted much attention due to their wide range of beneficial effects. We evaluated the cytocompatibility and the anti-inflammatory and anti-oxidant effects of nanoceria on endothelial umbilical vein endothelail cells (HUVECs). Methods and results: HUVECs were incubated for 24 and 48h with nanoceria in cell culture medium at 50 μg/mL. Cell viability was assayed by WST-1 assay, vascular adhesion molecule (VCAM-1) expression by surface enzyme immunoassay, intracellular ROS production by the fluorescent probe 6-carboxy-2'-7'-dichlorofluoresceine, cytokine production by ELISA assay and interaction nanoparticles/cells evaluated by transmission electron microscopy (TEM). Nanoceria did not affect cell growth and vitality in HUVECs at any of the incubation time. Nanoceria reduced the H2O2 (25 μmol/L)-induced ROS production in a time-dependent manner (-40%±10%, -26%±8%, p<0.05, at 48 and 24 h, respectively) and VCAM-1 surface exposure induced by TNF-α (25 ng/mL). (-35%± 6% at 24 h, p<0.01). Moreover, nanoceria significantly reduced IL-6 (38±1.9 pg/mL and 34±1.5 pg/mL vs TNF-α 45±2.25 pg/mL, at 24 and 48h respectively, p<0.05) and Il-8 (633±31 pg/mL and 807±40 pg/mL vs TNF-α 885±27 pg/mL, at 24 and 48h respectively, p<0.05) release in cell culture medium after stimulation with TNF-α. TEM analysis revealed that nanoceria was uptake by HUVECs and after 24h its localization found mostly in the cytoplasm without a preferential subcellular site. Conclusions: These findings highlight the antioxidant and antiinflammatory activity of nanoceria in the endothelium, that combined with lack of toxicity, makes it an extremely promising therapeutic tool.