1. Department of Comprehensive Medicine, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, P.R. China
2. Department of Pathology, College of Basic Sciences, Ningxia Medical University, Yinchuan, Ningxia, P.R. China
3. Department of Environmental, Earth and Geospatial Sciences, North Carolina Central University, Durham, North Carolina, USA.
4. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute and Technological Enterprise (BRITE), North Carolina Central University, Durham, North Carolina, USA.
5. Department of Neurological Surgery, University of Wisconsin, School of Medicine and Public Health, Madison, WI 53792, USA
6. Department of Epidemiology and Biostatistics, School of Public Health, Ningxia Medical University, Yinchuan, China
† Equal contribution
Silver nanoparticles (AgNP), one of the most commonly used engineered nanomaterial for biomedical and industrial applications, has shown a toxic potential to our ecosystems and humans. In this study, murine hippocampal neuronal HT22 cells were used to delineate subcellular responses and mechanisms to AgNP by assessing the response levels of caspase-3, mitochondrial oxygen consumption, reactive oxygen species (ROS), and mitochondrial membrane potential in addition to cell viability testing. Selenium, an essential trace element that has been known to carry protecting property from heavy metals, was tested for its ameliorating potential in the cells exposed to AgNP. Results showed that AgNP reduced cell viability. The toxicity was associated with mitochondrial membrane depolarization, increased accumulation of ROS, elevated mitochondrial oxygen consumption, and caspase-3 activation. Treatment with sodium selenite reduced cell death, stabilized mitochondrial membrane potential and oxygen consumption rate, and prevented accumulation of ROS and activation of caspase-3. It is concluded that AgNP induces mitochondrial stress and treatment with selenite is capable of preventing the adverse effects of AgNP on the mitochondria.
Keywords: Engineered nanomaterial, Silver nanoparticles, Mitochondrial stress, Caspase, Reactive Oxygen Species, Cell death, Selenium