University of Lodz, Faculty of Biology and Environmental Protection, Department of Biophysics of Environmental Pollution, 141/143 Pomorska St., 90-236, Lodz, Poland.
University of Lodz, Faculty of Biology and Environmental Protection, Department of Biophysics of Environmental Pollution, 141/143 Pomorska St., 90-236, Lodz, Poland.
Chemosphere. 2023 Sep;335:139137. doi: 10.1016/j.chemosphere.2023.139137. Epub 2023 Jun 5.
Particles of various types of plastics, including polystyrene nanoparticles (PS-NPs), have been determined in human blood, placenta, and lungs. These findings suggest a potential detrimental effect of PS-NPs on bloodstream cells. The purpose of this study was to assess the mechanism underlying PS-NPs-induced apoptosis in human peripheral blood mononuclear cells (PBMCs). Non-functionalized PS-NPs of three diameters: 29 nm, 44 nm, and 72 nm were studied used in this research. PBMCs were isolated from human leukocyte-platelet buffy coat and treated with PS-NPs at concentrations ranging from 0.001 to 200 μg/mL for 24 h. Apoptotic mechanism of action was evaluated by determining the level of cytosolic calcium ions, as well as mitochondrial transmembrane potential, and ATP levels. Furthermore, detection of caspase-8, -9, and -3 activation, as well as mTOR level was conducted. The presence of apoptotic PBMCs was confirmed by the method of double staining of the cells with propidium iodide and FITC-conjugated Annexin V. We found that all tested NPs increased calcium ion and depleted mitochondrial transmembrane potential levels. The tested NPs also activated caspase-9 and caspase-3, and the smallest NPs of 29 nm of diameter also activated caspase-8. The results clearly showed that apoptotic changes and an increase of mTOR level depended on the size of the tested NPs, while the smallest particles caused the greatest alterations. PS-NPs of 26 nm of diameter activated the extrinsic pathway (increased caspase-8 activity), as well as intrinsic (mitochondrial) pathway (increased caspase-9 activity, raised calcium ion level, and decreased transmembrane mitochondrial potential) of apoptosis. All PS-NPs increased mTOR level at the concentrations smaller than those that induced apoptosis and its level returned to control value when the process of apoptosis escalated.
各种类型的塑料颗粒，包括聚苯乙烯纳米颗粒（PS-NPs），已在人体血液、胎盘和肺部中被发现。这些发现表明 PS-NPs 对血液细胞可能有潜在的有害影响。本研究旨在评估 PS-NPs 诱导人外周血单个核细胞（PBMCs）凋亡的机制。本研究使用三种直径的非功能化 PS-NPs：29nm、44nm 和 72nm。从人白细胞-血小板缓冲层中分离 PBMCs，并在浓度范围为 0.001 至 200μg/mL 的 PS-NPs 下处理 24 小时。通过测定细胞质钙离子水平、线粒体跨膜电位和 ATP 水平来评估凋亡作用机制。此外，还检测了 caspase-8、-9 和 -3 的激活以及 mTOR 水平。通过碘化丙啶和 FITC 缀合的 Annexin V 双重染色细胞的方法来确认凋亡 PBMCs 的存在。我们发现所有测试的 NPs 均增加了钙离子并耗竭了线粒体跨膜电位。测试的 NPs 还激活了 caspase-9 和 caspase-3，而直径 29nm 的最小 NPs 还激活了 caspase-8。结果清楚地表明，凋亡变化和 mTOR 水平的增加取决于所测试的 NPs 的大小，而最小的颗粒会引起最大的变化。直径 26nm 的 PS-NPs 激活了外源性途径（增加 caspase-8 活性）以及内源性（线粒体）途径（增加 caspase-9 活性、提高钙离子水平和降低跨膜线粒体电位）的凋亡。所有 PS-NPs 在引起凋亡的浓度以下均增加了 mTOR 水平，当凋亡过程加剧时，其水平恢复到对照值。
