Silica Nanoparticles Induce Oxidative Stress and Autophagy but Not Apoptosis in the MRC-5 Cell Line

Abstract

This study evaluated the in vitro effects of 62.5 µg/mL silica nanoparticles (SiO2 NPs) on MRC-5 human lung fibroblast cells for 24, 48 and 72 h. The nanoparticles’ morphology, composition, and structure were investigated using high resolution transmission electron microscopy, selected area electron diffraction and X-ray diffraction. Our study showed a decreased cell viability and the induction of cellular oxidative stress as evidenced by an increased level of reactive oxygen species (ROS), carbonyl groups, and advanced oxidation protein products after 24, 48, and 72 h, as well as a decreased concentration of glutathione (GSH) and protein sulfhydryl groups. The protein expression of Hsp27, Hsp60, and Hsp90 decreased at all time intervals, while the level of protein Hsp70 remained unchanged during the exposure. Similarly, the expression of p53, MDM2 and Bcl-2 was significantly decreased for all time intervals, while the expression of Bax, a marker for apoptosis, was insignificantly downregulated. These results correlated with the increase of pro-caspase 3 expression. The role of autophagy in cellular response to SiO2 NPs was demonstrated by a fluorescence-labeled method and by an increased level of LC3-II/LC3-I ratio. Taken together, our data suggested that SiO2 NPs induced ROS-mediated autophagy in MRC-5 cells as a possible mechanism of cell survival.

The Effect of Silica Nanoparticles on Human Corneal Epithelial Cells

“…As mentioned earlier, HCEC is the first encounter cells of topically instilled eye drop. It is already known that SiNPs can induce oxidative stress and autophagy when cultured with various types of cells373839. The increased ROS generation observed in our study is consistent with previous reports.…”

Graphene oxide induces cytotoxicity and oxidative stress in bluegill sunfish cells

“…Human lung epithelial cells exposed to nickel NPs have shown a significant rise in LPO (Ahamed, ). The MRC‐5 cells exposed to SiO 2 NPs have also shown an increment in LPO identical to our studies (Petrache Voicu et al, ). Identical to our results a significant increase in LPO was prominent in WAG cells exposed to TiO 2 and ZnO NPs (Dubey, Goswami, Yadav, & Chaudhary, ).…”

Mass spectrometry-based proteomics for system-level characterization of biological responses to engineered nanomaterials

“…The authors used fluorescein-5-thiosemicarbazide to label protein carbonyls, which were later separated and visualized on a 2D-gel. However, an overall increase of carbonyl groups was observed in MRC-5 human lung fibroblast cells following exposure to SiO 2 ENMs [66]. In a more comprehensive study, the effects on protein carbonylation of a panel of 24 representative ENMs, including amorphous silica, metal oxide, carbon nanotubes, and silver, were assessed in NRK-52E cells [31].…”

“…For example, the ROS level in MRC-5 human lung fibroblast cells increased after 24, 48, and 72 h exposure to SiO 2 ENMs. On the other hand, the levels of glutathione (GSH) decreased at all time points measured [66]. Likewise, the free GSH levels in macrophages were also decreased under the treatment of copper-based ENMs, indicative of a shift in redox homeostasis [70].…”