Pulmonary inflammation induced by low-dose particulate matter exposure in mice. - GreenMedInfo Summary
Pulmonary inflammation induced by low-dose particulate matter exposure in mice.
Am J Physiol Lung Cell Mol Physiol. 2019 Sep 1 ;317(3):L424-L430. Epub 2019 Jul 31. PMID: 31364371
Yik Lung Chan
Air pollution is a ubiquitous problem and comprises gaseous and particulate matter (PM). Epidemiological studies have clearly shown that exposure to PM is associated with impaired lung function and the development of lung diseases, such as chronic obstructive pulmonary disease and asthma. To understand the mechanisms involved, animal models are often used. However, the majority of such models represent high levels of exposure and are not representative of the exposure levels in less polluted countries, such as Australia. Therefore, in this study, we aimed to determine whether low dose PMexposure has any detrimental effect on the lungs. Mice were intranasally exposed to saline or traffic-related PM(1μg or 5μg/day) for 3 wk. Bronchoalveolar lavage (BAL) and lung tissue were analyzed. PMat 1μg did not significantly affect inflammatory and mitochondrial markers. At 5 μg, PMexposure increased lymphocytes and macrophages in BAL fluid. Increased NACHT, LRR and PYD domains-containing protein 3 (NLRP3) and IL-1β production occurred following PMexposure. PM(5μg) exposure reduced mitochondrial antioxidant manganese superoxide (antioxidant defense system) and mitochondrial fusion marker (OPA-1), while it increased fission marker (Drp-1). Autophagy marker light-chain 3 microtubule-associated protein (LC3)-II and phosphorylated-AMPK were reduced, and apoptosis marker (caspase 3) was increased. No significant change of remodeling markers was observed. In conclusion, a subchronic low-level exposure to PM can have an adverse effect on lung health, which should be taken into consideration for the planning of roads and residential buildings.