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ZnO Nanoparticles Treatment Induces Apoptosis by Increasing Intracellular ROS Levels in LTEP-a-2 Cells.

Wang C, Hu X, Gao Y, Ji Y - Biomed Res Int (2015)

Bottom Line: Both intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) were examined by a microplate-reader method.Results showed that ZnO NPs (≥ 0.01 μg/mL) significantly inhibited proliferation (P < 0.05) and induced substantial apoptosis in LTEP-a-2 cells after 4 h of exposure.The intracellular ROS level rose up to 30-40% corresponding to significant depletion (approximately 70-80%) in GSH content in LTEP-a-2 cells (P < 0.05), suggesting that ZnO NPs induced apoptosis mainly through increased ROS production.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Road, Laishan District, Yantai 264003, China ; University of Chinese Academy of Sciences, Beijing 100049, China.

ABSTRACT
Owing to the wide use of novel nanoparticles (NPs) such as zinc oxide (ZnO) in all aspects of life, toxicological research on ZnO NPs is receiving increasing attention in these days. In this study, the toxicity of ZnO NPs in a human pulmonary adenocarcinoma cell line LTEP-a-2 was tested in vitro. Log-phase cells were exposed to different levels of ZnO NPs for hours, followed by colorimetric cell viability assay using tetrazolium salt and cell survival rate assay using trypan blue dye. Cell morphological changes were observed by Giemsa staining and light microscopy. Apoptosis was detected by using fluorescence microscopy and caspase-3 activity assay. Both intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) were examined by a microplate-reader method. Results showed that ZnO NPs (≥ 0.01 μg/mL) significantly inhibited proliferation (P < 0.05) and induced substantial apoptosis in LTEP-a-2 cells after 4 h of exposure. The intracellular ROS level rose up to 30-40% corresponding to significant depletion (approximately 70-80%) in GSH content in LTEP-a-2 cells (P < 0.05), suggesting that ZnO NPs induced apoptosis mainly through increased ROS production. This study elucidates the toxicological mechanism of ZnO NPs in human pulmonary adenocarcinoma cells and provides reference data for application of nanomaterials in the environment.

No MeSH data available.


Related in: MedlinePlus

ZnO nanoparticles-induced morphological changes in LTEP-a-2 cells examined by Giemsa staining. Note significant changes in cells after 4 h of exposure to ZnO NPs (0 μg/mL, control).
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fig4: ZnO nanoparticles-induced morphological changes in LTEP-a-2 cells examined by Giemsa staining. Note significant changes in cells after 4 h of exposure to ZnO NPs (0 μg/mL, control).

Mentions: Giemsa staining is commonly used for identifying morphological changes of monocytes/macrophages in cell preparation [28]. In the present study, Giesma staining was used to examine ZnO NPs-induced morphological changes in LTEP-a-2 cells for further characterizing the cytotoxicity of this nanomaterial. Microscopic examinations revealed that Giemsa-stained control cells (0 μg/mL ZnO NPs) predominantly had round regular cell margins and large nuclei (Figure 4); that is, the control cells were associated with rapid DNA synthesis and fast proliferation. With increasing concentrations of ZnO NPs (0.05, 0.1, and 0.5 μg/mL), there were evident increases in the number of pyknotic shrinking cells following a dose-dependent manner (Figure 4); the increasing morphological changes in the presence of ZnO NPs coincided well with the declines in cell survival rate (Figure 3); thus they were associated with proliferation inhibition and/or cell death.


ZnO Nanoparticles Treatment Induces Apoptosis by Increasing Intracellular ROS Levels in LTEP-a-2 Cells.

Wang C, Hu X, Gao Y, Ji Y - Biomed Res Int (2015)

ZnO nanoparticles-induced morphological changes in LTEP-a-2 cells examined by Giemsa staining. Note significant changes in cells after 4 h of exposure to ZnO NPs (0 μg/mL, control).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4538331&req=5

fig4: ZnO nanoparticles-induced morphological changes in LTEP-a-2 cells examined by Giemsa staining. Note significant changes in cells after 4 h of exposure to ZnO NPs (0 μg/mL, control).
Mentions: Giemsa staining is commonly used for identifying morphological changes of monocytes/macrophages in cell preparation [28]. In the present study, Giesma staining was used to examine ZnO NPs-induced morphological changes in LTEP-a-2 cells for further characterizing the cytotoxicity of this nanomaterial. Microscopic examinations revealed that Giemsa-stained control cells (0 μg/mL ZnO NPs) predominantly had round regular cell margins and large nuclei (Figure 4); that is, the control cells were associated with rapid DNA synthesis and fast proliferation. With increasing concentrations of ZnO NPs (0.05, 0.1, and 0.5 μg/mL), there were evident increases in the number of pyknotic shrinking cells following a dose-dependent manner (Figure 4); the increasing morphological changes in the presence of ZnO NPs coincided well with the declines in cell survival rate (Figure 3); thus they were associated with proliferation inhibition and/or cell death.

Bottom Line: Both intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) were examined by a microplate-reader method.Results showed that ZnO NPs (≥ 0.01 μg/mL) significantly inhibited proliferation (P < 0.05) and induced substantial apoptosis in LTEP-a-2 cells after 4 h of exposure.The intracellular ROS level rose up to 30-40% corresponding to significant depletion (approximately 70-80%) in GSH content in LTEP-a-2 cells (P < 0.05), suggesting that ZnO NPs induced apoptosis mainly through increased ROS production.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Road, Laishan District, Yantai 264003, China ; University of Chinese Academy of Sciences, Beijing 100049, China.

ABSTRACT
Owing to the wide use of novel nanoparticles (NPs) such as zinc oxide (ZnO) in all aspects of life, toxicological research on ZnO NPs is receiving increasing attention in these days. In this study, the toxicity of ZnO NPs in a human pulmonary adenocarcinoma cell line LTEP-a-2 was tested in vitro. Log-phase cells were exposed to different levels of ZnO NPs for hours, followed by colorimetric cell viability assay using tetrazolium salt and cell survival rate assay using trypan blue dye. Cell morphological changes were observed by Giemsa staining and light microscopy. Apoptosis was detected by using fluorescence microscopy and caspase-3 activity assay. Both intracellular reactive oxygen species (ROS) and reduced glutathione (GSH) were examined by a microplate-reader method. Results showed that ZnO NPs (≥ 0.01 μg/mL) significantly inhibited proliferation (P < 0.05) and induced substantial apoptosis in LTEP-a-2 cells after 4 h of exposure. The intracellular ROS level rose up to 30-40% corresponding to significant depletion (approximately 70-80%) in GSH content in LTEP-a-2 cells (P < 0.05), suggesting that ZnO NPs induced apoptosis mainly through increased ROS production. This study elucidates the toxicological mechanism of ZnO NPs in human pulmonary adenocarcinoma cells and provides reference data for application of nanomaterials in the environment.

No MeSH data available.


Related in: MedlinePlus