Presentation Type

Poster

Keywords

Biology, inositol triphosphate, apoptosis, human alveolar lung cells, nanoparticles, stress signaling

Department

Biology

Major

Biology

Abstract

The signaling of cell stress in response to organelle dysfunction, toxin exposure, and mutation is complex; generating responses that can include adaptation, or in severe cases, cellular apoptosis. Nanoparticles (20-100 nm diameter) have been shown to induce cell stress in lung cells, potentially identifying a cause of lung disease in areas with high levels of particulate-based air pollution. This study examines the effect of carbon black (CB) and titanium dioxide (TiO2) nanoparticles on stress signaling and apoptosis in cultured A549 human alveolar epithelial cells. CB and TiO2 powders were dispersed throughout a buffered solution containing bovine serum albumin using probe sonication. Particle size analysis was performed, revealing stable nanoparticle complexes ranging from 75 nm for CB and from 172 nm for TiO2. A range of nanoparticle doses between 5 and 100 μg/mL were evaluated for toxicity using a visual inspection for DAPI-stained apoptotic nuclei. This assay revealed a peak of cell death activation at 75 μg/mL for CB and 100 μg/mL for TiO2 though the CB was more effective at inducing apoptosis than TiO2. A live/dead-cell fluorescent protease assay confirmed CB to significantly decrease cell viability. Further studies revealed acute CB exposure, but not TiO2 exposure, to induce reactive oxygen species (ROS). Interestingly, inhibition of nanoparticle-induced calcium release by the inositol triphosphate receptor (ITPR) inhibited ROS production, suggesting a role for ER Ca2+ stores in activating ROS production. Further research is underway to determine which stress/apoptotic signaling pathways are induced downstream of nanoparticle exposure.

Faculty Mentor

Jay Brewster

Funding Source or Research Program

Summer Undergraduate Research Program, Undergraduate Research Fellowship

Location

Waves Cafeteria, Tyler Campus Center

Start Date

21-3-2014 2:00 PM

End Date

21-3-2014 3:00 PM

Share

COinS
 
Mar 21st, 2:00 PM Mar 21st, 3:00 PM

Nanoparticle exposure activates an inositol triphosphate receptor-dependent elevation of reactive oxygen species and apoptosis in human alveolar lung cells

Waves Cafeteria, Tyler Campus Center

The signaling of cell stress in response to organelle dysfunction, toxin exposure, and mutation is complex; generating responses that can include adaptation, or in severe cases, cellular apoptosis. Nanoparticles (20-100 nm diameter) have been shown to induce cell stress in lung cells, potentially identifying a cause of lung disease in areas with high levels of particulate-based air pollution. This study examines the effect of carbon black (CB) and titanium dioxide (TiO2) nanoparticles on stress signaling and apoptosis in cultured A549 human alveolar epithelial cells. CB and TiO2 powders were dispersed throughout a buffered solution containing bovine serum albumin using probe sonication. Particle size analysis was performed, revealing stable nanoparticle complexes ranging from 75 nm for CB and from 172 nm for TiO2. A range of nanoparticle doses between 5 and 100 μg/mL were evaluated for toxicity using a visual inspection for DAPI-stained apoptotic nuclei. This assay revealed a peak of cell death activation at 75 μg/mL for CB and 100 μg/mL for TiO2 though the CB was more effective at inducing apoptosis than TiO2. A live/dead-cell fluorescent protease assay confirmed CB to significantly decrease cell viability. Further studies revealed acute CB exposure, but not TiO2 exposure, to induce reactive oxygen species (ROS). Interestingly, inhibition of nanoparticle-induced calcium release by the inositol triphosphate receptor (ITPR) inhibited ROS production, suggesting a role for ER Ca2+ stores in activating ROS production. Further research is underway to determine which stress/apoptotic signaling pathways are induced downstream of nanoparticle exposure.