Department of Pharmacology, Medical University of Bialystok, Bialystok, Poland.
Adv Exp Med Biol. 2020;1271:61-68. doi: 10.1007/5584_2019_474.
The ability of air particulate matter (PM) to cause reactive oxygen species-driven protein damage is associated with both COPD and lung cancer, but the mechanisms are unsettled. In this study, we investigated the co-expression of Hsp70 and the autophagy marker protein LC3 in A549 cells (alveolar epithelial cell line) and THP-1 cells (monocyte/macrophage cells) grown in media supplemented with 100 μg/mL of four types of PM: carbon black (CB), urban dust (UD), nanoparticulate CB (NPCB), and nanoparticulate CB coated with benzo(a)pyrene (NPCB-BaP). Fluorescent monoclonal antibodies and flow cytometry were used to assess the expression and co-expression of HSP70 and LC3 proteins. Hsp70 expression was significantly increased by all PM, while LC3 was decreased by CB in A549 cells, unchanged by CB and UD in THP-1 cells and increased by NPCB and NPCB-BaP in both cell types. All PMs increased the Hsp70/LC3 ratio in binary scatterplots; the relationship was positive and linear, which may reflect chaperone-dependent autophagy. The UD was the only PM type that affected the slopes of the spatial trend lines and altered binary patterns of Hsp70/LC3 distribution in THP1 cells. These findings provide an insight into the molecular mechanisms regulating proteostasis in PM-exposed cells through the chaperone-autophagy system in the cytoplasm.
空气颗粒物（PM）引起活性氧物种驱动的蛋白质损伤的能力与 COPD 和肺癌都有关，但机制尚未确定。在这项研究中，我们研究了四种类型的 PM（炭黑（CB）、城市尘埃（UD）、纳米颗粒 CB（NPCB）和涂有苯并芘的纳米颗粒 CB（NPCB-BaP））在补充有 100μg/mL PM 的培养基中培养的 A549 细胞（肺泡上皮细胞系）和 THP-1 细胞（单核细胞/巨噬细胞）中 Hsp70 和自噬标记蛋白 LC3 的共表达。使用荧光单克隆抗体和流式细胞术评估 HSP70 和 LC3 蛋白的表达和共表达。所有 PM 均显著增加了 Hsp70 的表达，而 CB 在 A549 细胞中降低了 LC3 的表达，CB 和 UD 在 THP-1 细胞中未改变，NPCB 和 NPCB-BaP 在两种细胞类型中均增加了 LC3 的表达。所有 PM 均在二值散点图中增加了 Hsp70/LC3 比值；这种关系是正线性的，这可能反映了伴侣蛋白依赖的自噬。UD 是唯一一种影响 THP1 细胞中 Hsp70/LC3 分布的空间趋势线斜率和改变二元模式的 PM 类型。这些发现为通过细胞质中的伴侣蛋白-自噬系统调节 PM 暴露细胞中的蛋白质稳定性的分子机制提供了深入了解。
