Department of Air quality and Noise, Division of Climate and Environmental Health, Norwegian Institute of Public Health, PO Box 222, Skøyen, Oslo, 0213, Norway.
Department of Industrial Economics and Technology Management, Norwegian University of Science and Technology, NTNU, Trondheim, Norway.
Part Fibre Toxicol. 2023 Aug 3;20(1):31. doi: 10.1186/s12989-023-00542-w.
Traffic-derived particles are important contributors to the adverse health effects of ambient particulate matter (PM). In Nordic countries, mineral particles from road pavement and diesel exhaust particles (DEP) are important constituents of traffic-derived PM. In the present study we compared the pro-inflammatory responses of mineral particles and DEP to PM from two road tunnels, and examined the mechanisms involved.
The pro-inflammatory potential of 100 µg/mL coarse (PM), fine (PM and ultrafine PM (PM) sampled in two road tunnels paved with different stone materials was assessed in human bronchial epithelial cells (HBEC3-KT), and compared to DEP and particles derived from the respective stone materials. Release of pro-inflammatory cytokines (CXCL8, IL-1α, IL-1β) was measured by ELISA, while the expression of genes related to inflammation (COX2, CXCL8, IL-1α, IL-1β, TNF-α), redox responses (HO-1) and metabolism (CYP1A1, CYP1B1, PAI-2) was determined by qPCR. The roles of the aryl hydrocarbon receptor (AhR) and reactive oxygen species (ROS) were examined by treatment with the AhR-inhibitor CH223191 and the anti-oxidant N-acetyl cysteine (NAC).
Road tunnel PM caused time-dependent increases in expression of CXCL8, COX2, IL-1α, IL-1β, TNF-α, COX2, PAI-2, CYP1A1, CYP1B1 and HO-1, with fine PM as more potent than coarse PM at early time-points. The stone particle samples and DEP induced lower cytokine release than all size-fractionated PM samples for one tunnel, and versus fine PM for the other tunnel. CH223191 partially reduced release and expression of IL-1α and CXCL8, and expression of COX2, for fine and coarse PM, depending on tunnel, response and time-point. Whereas expression of CYP1A1 was markedly reduced by CH223191, HO-1 expression was not affected. NAC reduced the release and expression of IL-1α and CXCL8, and COX2 expression, but augmented expression of CYP1A1 and HO-1.
The results indicate that the pro-inflammatory responses of road tunnel PM in HBEC3-KT cells are not attributed to the mineral particles or DEP alone. The pro-inflammatory responses seem to involve AhR-dependent mechanisms, suggesting a role for organic constituents. ROS-mediated mechanisms were also involved, probably through AhR-independent pathways. DEP may be a contributor to the AhR-dependent responses, although other sources may be of importance.
交通衍生颗粒是大气颗粒物（PM）对健康产生不良影响的重要因素。在北欧国家，来自路面的矿物颗粒和柴油 exhaust 颗粒（DEP）是交通衍生 PM 的重要组成部分。在本研究中，我们比较了两条道路隧道中 PM 中矿物颗粒和 DEP 的促炎反应，并研究了其中涉及的机制。
通过酶联免疫吸附试验（ELISA）测定了来自两条不同石材路面的隧道中采集的粗（PM）、细（PM 和超细 PM（PM））100µg/mL 浓度下的促炎潜能，并与 DEP 和各自石材材料衍生的颗粒进行了比较。通过 qPCR 测定了与炎症相关的基因（COX2、CXCL8、IL-1α、IL-1β、TNF-α）、氧化还原反应（HO-1）和代谢（CYP1A1、CYP1B1、PAI-2）的表达。通过用芳香烃受体（AhR）抑制剂 CH223191 和抗氧化剂 N-乙酰半胱氨酸（NAC）处理，研究了 AhR 和活性氧（ROS）的作用。
隧道 PM 导致 CXCL8、COX2、IL-1α、IL-1β、TNF-α、COX2、PAI-2、CYP1A1、CYP1B1 和 HO-1 的表达呈时间依赖性增加，其中细颗粒 PM 在早期时间点比粗颗粒 PM 更有效。对于一条隧道，石材颗粒样本和 DEP 诱导的细胞因子释放低于所有大小分级的 PM 样本，而对于另一条隧道，则低于细颗粒 PM。CH223191 部分降低了细和粗 PM 诱导的 IL-1α 和 CXCL8 的释放和表达，以及 COX2 的表达，这取决于隧道、反应和时间点。而 CH223191 显著降低了 CYP1A1 的表达，但不影响 HO-1 的表达。NAC 降低了 IL-1α 和 CXCL8 的释放和表达，以及 COX2 的表达，但增加了 CYP1A1 和 HO-1 的表达。
结果表明，HBEC3-KT 细胞中道路隧道 PM 的促炎反应并非仅归因于矿物颗粒或 DEP。促炎反应似乎涉及 AhR 依赖性机制，表明有机成分的作用。ROS 介导的机制也参与其中，可能通过 AhR 非依赖性途径。DEP 可能是 AhR 依赖性反应的一个贡献因素，尽管其他来源可能更为重要。
