Department of Hygiene and Public Health I, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
Toxicol In Vitro. 2018 Feb;46:148-154. doi: 10.1016/j.tiv.2017.10.009. Epub 2017 Oct 5.
Although silver nanoparticles (AgNPs) are widely used in consumer and medical products, the mechanism by which AgNPs cause pulmonary damage is unclear. AgNPs are incorporated into cells and processed via the autophagy pathway. We examined the effects of AgNP exposure on autophagic flux and expression of transcription factor EB (TFEB) in A549 lung adenocarcinoma cells. In cells exposed to citrate-coated 60-nm AgNPs, confocal laser microscopic examination showed a decrease in the LysoTracker fluorescence signal and an increase in that of Cyto-ID, indicating lysosomal pH alkalization and autophagosome formation, respectively. The proteins p62 and microtubule-associated protein light chain 3B-II (LC3B-II) are both degraded by autophagy, and their levels increased depending on AgNP dose. Furthermore, AgNP-induced increase in LC3B-II was not enhanced by treatment with the autophagic inhibitor bafilomycin A1. TFEB mRNA levels, and protein levels in cytosolic and nuclear fractions, were suppressed by exposure to AgNPs, suggesting transcriptional inhibition of TFEB expression. Overexpression of TFEB did not suppress AgNP-induced LC3B-II accumulation and cellular damage, indicating that impairment of autophagic flux and cellular damage by AgNPs might not be primarily caused by reduced TFEB expression. The present study suggests that AgNP-induced lysosomal dysfunction plays a principal role in the autophagic flux defect.
尽管纳米银颗粒(AgNPs)广泛应用于消费和医疗产品,但 AgNPs 导致肺部损伤的机制尚不清楚。AgNPs 被细胞内吞并通过自噬途径进行处理。我们研究了 AgNP 暴露对 A549 肺腺癌细胞自噬流和转录因子 EB(TFEB)表达的影响。在暴露于柠檬酸包覆的 60nmAgNPs 的细胞中,共聚焦激光显微镜检查显示溶酶体荧光信号减少,Cyto-ID 荧光信号增加,分别表明溶酶体 pH 碱化和自噬体形成。自噬体降解蛋白 p62 和微管相关蛋白轻链 3B-II(LC3B-II),其水平随 AgNP 剂量增加而增加。此外,AgNP 诱导的 LC3B-II 增加不受自噬抑制剂巴弗洛霉素 A1 的增强。AgNPs 暴露抑制 TFEB mRNA 水平和胞质和核部分的 TFEB 蛋白水平,表明 TFEB 表达的转录抑制。TFEB 的过表达不能抑制 AgNP 诱导的 LC3B-II 积累和细胞损伤,表明 AgNPs 引起的自噬流缺陷和细胞损伤可能不是主要由 TFEB 表达减少引起的。本研究表明,AgNP 诱导的溶酶体功能障碍在自噬流缺陷中起主要作用。
Food Chem Toxicol. 2020-10
Toxicol Appl Pharmacol. 2020-6-5
Nanotoxicology. 2016-10
Acta Pharm Sin B. 2024-6
Int J Mol Sci. 2023-10-20
Pharmaceuticals (Basel). 2022-8-5
Nanomaterials (Basel). 2022-7-5
Int J Nanomedicine. 2022
Int J Mol Sci. 2021-4-30
Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2021-3