Int J Biol Sci 2018; 14(5):557-564. doi:10.7150/ijbs.24546 This issue

Research Paper

PM2.5 induces autophagy-mediated cell death via NOS2 signaling in human bronchial epithelium cells

Xiao-Ming Zhu1, Qin Wang2, Wei-Wei Xing1, Min-Hui Long1, Wen-Liang Fu1, Wen-Rong Xia1, Chen Jin1, Ning Guo1, Dong-Qun Xu2✉, Dong-Gang Xu1✉

1. Institute of Military Cognitive and Brain Sciences, Academy of Military Medical Sciences, Beijing, 100850, China
2. Institute for Environmental Health and Related Product Safety, China, CDC, Beijing, 100021, China

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license ( See for full terms and conditions.
Zhu XM, Wang Q, Xing WW, Long MH, Fu WL, Xia WR, Jin C, Guo N, Xu DQ, Xu DG. PM2.5 induces autophagy-mediated cell death via NOS2 signaling in human bronchial epithelium cells. Int J Biol Sci 2018; 14(5):557-564. doi:10.7150/ijbs.24546. Available from

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Graphic abstract

The biggest victim of ambient air pollution is the respiratory system. Mainly because of the harmful components, especially the particulate matters with an aerodynamic diameter of ≤ 2.5µm (PM2.5), can be directly inhaled and deeply penetrate into the lung alveoli, thus causing severe lung dysfunction, including chronic cough, bronchitis and asthma, even lung cancer. Unfortunately, the toxicological mechanisms of PM2.5 associations with these adverse respiratory outcomes have still not been clearly unveiled. Here, we found that PM2.5 rapidly induced inflammatory responses, oxidative injure and cell death in human bronchial epithelium cells through upregulation of IL-6 expression, ROS production and apoptosis. Furthermore, PM2.5 specifically induced nitric oxide synthase 2 (NOS2) expression and NO generation to elevate excessive autophagy. Finally, disruption of NOS2 signaling effectively blocked autophayosome formation and the subsequent cell death. Our novel findings systemically reveled the role of autophagy-mediated cell death in PM2.5-treated human bronchial epithelium cells and provided potential strategy for future clinic intervention.

Keywords: Particulate matters two point five (PM2.5), Human bronchial epithelium cells, Autophagy-mediated cell death, NOS2 signaling, Clinic intervention