Coronavirus disease (COVID-19) is currently a serious global issue. Epidemiological studies have identified air pollutants, including particulate matter (PM), as a risk factor for COVID-19 infection and severity of illness, in addition to numerous factors such as pre-existing conditions, aging and smoking. However, the mechanisms by which air pollution is involved in the manifestation and/or progression of COVID-19 is still unknown. In this study, we used a mouse model exposed to crude PM, collected by the cyclone method, to evaluate the pulmonary expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine type 2 (TMPRSS2), the two molecules required for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells. Multiplex immunohistochemical analysis revealed that exposure to PM increased the expression of these two molecules at the same site. Furthermore, image cytometry analysis revealed increased expression of these proteins, particularly, in the alveolar type 2 cells and macrophages, which are potential targets for SARS-CoV-2. Our findings provide an experimental evidence that exposure to PM may adversely affect the manifestation and progression of COVID-19, mediated by the impact of SARS-CoV-2 on the site of entry. The study results suggest that examining these effects might help to advance our understanding of COVID-19 and aid the development of appropriate social interventions.

冠状病毒病 (COVID-19) 目前是一个严重的全球性问题。流行病学研究已将包括颗粒物 (PM) 在内的空气污染物确定为 COVID-19 感染和疾病严重程度的风险因素，此外还有许多因素，如原有疾病、衰老和吸烟。然而，空气污染参与 COVID-19 的表现和/或进展的机制仍然未知。在这项研究中，我们使用通过旋风法收集的暴露于粗 PM 的小鼠模型来评估血管紧张素转换酶 2 (ACE2) 和跨膜蛋白酶丝氨酸 2 型 (TMPRSS2) 的肺表达，这两种分子是严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 进入宿主细胞。多重免疫组织化学分析显示，暴露于 PM 会增加这两种分子在同一部位的表达。此外，图像细胞术分析显示这些蛋白质的表达增加，特别是在肺泡 2 型细胞和巨噬细胞中，它们是 SARS-CoV-2 的潜在靶标。我们的研究结果提供了一个实验证据，表明暴露于 PM 可能会对 COVID-19 的表现和进展产生不利影响，这是由 SARS-CoV-2 对进入部位的影响所介导的。研究结果表明，检查这些影响可能有助于增进我们对 COVID-19 的理解，并有助于制定适当的社会干预措施。在肺泡 2 型细胞和巨噬细胞中，它们是 SARS-CoV-2 的潜在靶标。我们的研究结果提供了一个实验证据，表明暴露于 PM 可能会对 COVID-19 的表现和进展产生不利影响，这是由 SARS-CoV-2 对进入部位的影响所介导的。研究结果表明，检查这些影响可能有助于增进我们对 COVID-19 的理解，并有助于制定适当的社会干预措施。在肺泡 2 型细胞和巨噬细胞中，它们是 SARS-CoV-2 的潜在靶标。我们的研究结果提供了一个实验证据，表明暴露于 PM 可能会对 COVID-19 的表现和进展产生不利影响，这是由 SARS-CoV-2 对进入部位的影响所介导的。研究结果表明，检查这些影响可能有助于增进我们对 COVID-19 的理解，并有助于制定适当的社会干预措施。