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Gao J, Lei T, Wang H, Luo K, Wang Y, Cui B, Yu Z, Hu X, Zhang F, Chen Y, Ding W, Lu Z. Dimethylarginine dimethylaminohydrolase 1 protects PM 2.5 exposure-induced lung injury in mice by repressing inflammation and oxidative stress. Part Fibre Toxicol 2022; 19:64. [PMID: 36242005 PMCID: PMC9569114 DOI: 10.1186/s12989-022-00505-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 10/06/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Airborne fine particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5) pollution is associated with the prevalence of respiratory diseases, including asthma, bronchitis and chronic obstructive pulmonary disease. In patients with those diseases, circulating asymmetric dimethylarginine (ADMA) levels are increased, which contributes to airway nitric oxide deficiency, oxidative stress and inflammation. Overexpression of dimethylarginine dimethylaminohydrolase 1 (DDAH1), an enzyme degrading ADMA, exerts protective effects in animal models. However, the impact of DDAH1/ADMA on PM2.5-induced lung injury has not been investigated. METHODS Ddah1-/- and DDAH1-transgenic mice, as well as their respective wild-type (WT) littermates, were exposed to either filtered air or airborne PM2.5 (mean daily concentration ~ 50 µg/m3) for 6 months through a whole-body exposure system. Mice were also acutely exposed to 10 mg/kg PM2.5 and/or exogenous ADMA (2 mg/kg) via intratracheal instillation every other day for 2 weeks. Inflammatory response, oxidative stress and related gene expressions in the lungs were examined. In addition, RAW264.7 cells were exposed to PM2.5 and/or ADMA and the changes in intracellular oxidative stress and inflammatory response were determined. RESULTS Ddah1-/- mice developed more severe lung injury than WT mice after long-term PM2.5 exposure, which was associated with greater induction of pulmonary oxidative stress and inflammation. In the lungs of PM2.5-exposed mice, Ddah1 deficiency increased protein expression of p-p65, iNOS and Bax, and decreased protein expression of Bcl-2, SOD1 and peroxiredoxin 4. Conversely, DDAH1 overexpression significantly alleviated lung injury, attenuated pulmonary oxidative stress and inflammation, and exerted opposite effects on those proteins in PM2.5-exposed mice. In addition, exogenous ADMA administration could mimic the effect of Ddah1 deficiency on PM2.5-induced lung injury, oxidative stress and inflammation. In PM2.5-exposed macrophages, ADMA aggravated the inflammatory response and oxidative stress in an iNOS-dependent manner. CONCLUSION Our data revealed that DDAH1 has a marked protective effect on long-term PM2.5 exposure-induced lung injury.
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Affiliation(s)
- Junling Gao
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Tong Lei
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Hongyun Wang
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China.,Cardiac Regeneration and Ageing Lab, Institute of Cardiovascular Sciences, School of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Kai Luo
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Yuanli Wang
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Bingqing Cui
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Zhuoran Yu
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Xiaoqi Hu
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Fang Zhang
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China
| | - Yingjie Chen
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - Wenjun Ding
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China.
| | - Zhongbing Lu
- College of Life Sciences, University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing, 100049, China.
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