Conclusions
In conclusion, short-term exposure to PM1 increased the ACE2 overexpression in lungs. Long-term exposure to PM1 decreased the ACE2 overexpression in emphysema. Air pollution may be a risk for SARS-CoV-2 adhesion during the development of COPD.
Methods
Sprague Dawley rats were exposed to unconcentrated traffic-related air pollution for 3 and 6 months. We examined lung injury markers, oxidative stress, inflammation, emphysema, ACE2 and angiotensin II receptor type 1 (AT1) and 2 (AT2) in the lungs after exposure.
Results
Lung injury occurred due to an increase in permeability and lactate dehydrogenase cytotoxicity was observed after 6 months of exposure to fine particulate matter of <1 μm in aerodynamic diameter (PM1). An α1-antitrypsin deficiency and neutrophil elastase production with emphysema development were observed after 6 months of PM1 exposure. 8-isoprostane and interleukin-6 were increased after 3 and 6 months of PM1 exposure. Caspase-3 was increased after exposure to PM1 for 6 months. Upregulation of ACE2 was found after 3 months of PM1 exposure; however, ACE2 had decreased by 6 months of PM1 exposure. AT1 and AT2 had significantly decreased after exposure to PM1 for 6 months. Furthermore, smooth muscle hypertrophy had occurred after 6 months of PM1 exposure. Conclusions: In