Dipartimento di Biologia e Biotecnologie Charles Darwin, Sapienza University of Rome, 00185 Rome, Italy.
Environ Res. 2011 Aug;111(6):765-74. doi: 10.1016/j.envres.2011.06.005. Epub 2011 Jul 8.
Insight into the mechanisms by which ambient air particulate matter mediates adverse health effects is needed to provide biological plausibility to epidemiological studies demonstrating an association between PM(10) exposure and increased morbidity and mortality. In vitro studies of the effects of air pollution on human cells help to establish conditions for the analysis of cause-effect relationships. One of the major challenges is to test native atmosphere in its complexity, rather than the various components individually. We have developed an in vitro system in which human monocyte-macrophage U937 cells are directly exposed to filters containing different amounts of PM(10) collected in the city of Rome. Transcriptional profiling obtained after short exposure (1h) of cells to a filter containing 1666μg PM(10) (77.6μg/cm(2)) using a macroarray panel of 1176 genes reveals a significant change in the mRNA level (>2 fold) for 87 genes relative to cells exposed to a control filter. Overall, 9 out of 87 modulated genes were annotated as "lung cancer". qRT-PCR confirmed the induction of relevant genes involved in DNA repair and apoptosis, specifically: ERCC1, TDG, DAD1 and MCL1. In cells exposed for 10min, 1h and 3h to different amounts of PM(10), transcription of TNFα and TRAP1, which code for a key pro-inflammatory cytokine and a mitochondrial protein involved in cell protection from oxidative stress, respectively, was shown to be modulated in a time-dependent, but not a dose-dependent manner. Taken together, these data indicate that it is possible to analyze the effects of untreated particulate matter on human cells by the direct-exposure approach we have developed, possibly providing new clues to traffic-related health hazard.
要为流行病学研究提供生物学依据，证明 PM（10）暴露与发病率和死亡率增加之间存在关联，就需要深入了解环境空气中颗粒物介导不良健康影响的机制。体外研究空气污染对人体细胞的影响有助于确定分析因果关系的条件。主要挑战之一是测试大气的复杂性，而不是单独测试各种成分。我们已经开发了一种体外系统，其中人单核细胞-巨噬细胞 U937 细胞直接暴露于含有不同量 PM（10）的过滤器中，这些 PM（10）是在罗马市收集的。使用包含 1176 个基因的宏阵列面板，对细胞进行短时间（1 小时）暴露于含有 1666μg PM（10）（77.6μg/cm（2））的过滤器后，获得转录谱，发现 87 个基因的 mRNA 水平（>2 倍）发生显著变化，与暴露于对照过滤器的细胞相比。总的来说，在 87 个被调节的基因中，有 9 个被注释为“肺癌”。qRT-PCR 证实了与 DNA 修复和细胞凋亡相关的基因的诱导，特别是 ERCC1、TDG、DAD1 和 MCL1。在细胞暴露于不同量 PM（10）的 10min、1h 和 3h 时，分别编码关键促炎细胞因子和线粒体蛋白的 TNFα 和 TRAP1 的转录被证明以时间依赖性但非剂量依赖性方式被调节。综上所述，这些数据表明，通过我们开发的直接暴露方法，可以分析未经处理的颗粒物对人体细胞的影响，可能为交通相关健康危害提供新线索。
