Effects of TiO2 and Co3O4 Nanoparticles on Circulating Angiogenic Cells

Abstract

Background and AimSparse evidence suggests a possible link between exposure to airborne nanoparticles (NPs) and cardiovascular (CV) risk, perhaps through mechanisms involving oxidative stress and inflammation. We assessed the effects of TiO2 and Co3O4 NPs in human circulating angiogenic cells (CACs), which take part in vascular endothelium repair/replacement.MethodsCACs were isolated from healthy donors’ buffy coats after culturing lymphomonocytes on fibronectin-coated dishes in endothelial medium for 7 days. CACs were pre-incubated with increasing concentration of TiO2 and Co3O4 (from 1 to 100 μg/ml) to test the effects of NP – characterized by Transmission Electron Microscopy – on CAC viability, apoptosis (caspase 3/7 activation), function (fibronectin adhesion assay), oxidative stress and inflammatory cytokine gene expression.ResultsNeither oxidative stress nor cell death were associated with exposure to TiO2 NP (except at the highest concentration tested), which, however, induced a higher pro-inflammatory effect compared to Co3O4 NPs (p<0.01). Exposure to Co3O4 NPs significantly reduced cell viability (p<0.01) and increased caspase activity (p<0.01), lipid peroxidation end-products (p<0.05) and pro-inflammatory cytokine gene expression (p<0.05 or lower). Notably, CAC functional activity was impaired after exposure to both TiO2 (p<0.05 or lower) and Co3O4 (p<0.01) NPs.ConclusionsIn vitro exposure to TiO2 and Co3O4 NPs exerts detrimental effects on CAC viability and function, possibly mediated by accelerated apoptosis, increased oxidant stress (Co3O4 NPs only) and enhancement of inflammatory pathways (both TiO2 and Co3O4 NPs). Such adverse effects may be relevant for a potential role of exposure to TiO2 and Co3O4 NPs in enhancing CV risk in humans.

Sodium-glucose cotransporter 2 inhibitors antagonize lipotoxicity in human myeloid angiogenic cells and ADP-dependent activation in human platelets: potential relevance to prevention of cardiovascular events

“…To evaluate potential SGLT2i cytotoxic action in MAC, we assessed cell viability by using VisionBlue fluorescence cell viability assay kit (Biovision, Mountain View, CA), following manufacturer's instructions, as already reported [16,21,23]. Briefly, MACs were cultured in 96-well culture plates at a density of 2.5 × 10 5 cells per well (in a volume of 100 µl of culture medium) and exposed to EMPA and DAPA (1, 10 and 100 µM) for 16 h. Ten microliters of VisionBlue reagent was added in each well and, following incubation (2 h at 37 °C), the fluorescent product was measured (excitation: 540 nm, emission: 586 nm) using Cary Eclipse spectrophotometer (Varian/Agilent, Santa Clara, CA, USA).…”

“…cDNA was obtained by iScript Reverse Transcription Kit (Bio-Rad Laboratories, Inc. Hercules, Ca, USA) starting from 250 ng of total RNA. Interleukin (IL)-1β, IL-8, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) gene expression was tested using SsoAdvanced Universal Probes Supermix (Bio-Rad) with TaqMan primers and probes (IL-1β: Hs01555410_m1; IL-8: Hs00174103_m1; TNF-α: Hs00174128_m1; MCP-1: Hs00234140_m1) (Applied Biosystems, Carlsbad, CA, USA) on a CFX Connect Real-Time (Bio-Rad), as previously reported [16,23]. Specific thermal cycling conditions were used: 98 °C for 30 s, followed by 40 amplification cycles (95 °C for 3 s; 60 °C for 20 s).…”

Oxidative stress by inorganic nanoparticles

“…Examples include cell senescence, cell death, proliferation, growth arrest, autophagy, and adaptation. Human circulating angiogenic cells (CACs) exposed to increasing concentrations (up to 100 µg/mL) of TiO 2 and tricobalt tetraoxide (Co 3 O 4 ) NPs exhibit significant reduction in cell viability, enhanced caspase activity, increased lipid peroxidation end products and upregulation of proinflammatory cytokine gene expression . After treatment by these NPs, CACs in vascular endothelium repair and replacement were subsequently impaired.…”

Assessment of Cellular Responses in Kidney Cells Exposed to Cobalt Oxide Nanoparticles

“…Similarly, Co 3 O 4 nanoparticles induced apoptosis (at 10-25 µg/mL) in leukemic cancer cells [24]. Spigoni et al [35] reported that Co 3 O 4 nanoparticles significantly reduced cell viability, and induced apoptosis, oxidative stress, caspase activity, and pro-inflammatory cytokine gene expression in vitro. They indicated that the adverse effects might be relevant for a potential role of exposure to titanium dioxide (TiO 2 ) and Co 3 O 4 nanoparticles in enhancing cardiovascular risk in humans.…”