Related Experiment Video
Updated: Sep 28, 2025
Bioluminescence Imaging of NADPH Oxidase Activity in Different Animal Models
Published on: October 22, 2012
NADPH oxidase 4 signaling in a ventilator-induced lung injury mouse model
Sang Hoon Lee1, Mi Hwa Shin1, Ah Young Leem1
1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Institute of Chest Diseases, Severance Hospital, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, 120-752, South Korea.
Background:
For patients with acute respiratory distress syndrome, a ventilator is essential to supply oxygen to tissues, but it may also cause lung damage. In this study, we investigated the role of NOX4 using NOX4 knockout (KO) mice and NOX4 inhibitors in a ventilator-induced lung injury (VILI) model.
Methods:
Wild-type (WT) male C57BL/6J mice and NOX4 knockout (KO) male mice were divided into five groups: (1) control group; (2) high tidal ventilation (HTV) group: WT mice + HTV ± DMSO; (3) NOX4 KO group; (4) NOX4 KO with HTV group; (5) NOX4 inhibitor group: WT mice + HTV + NOX4 inhibitor. In the VILI model, the supine position was maintained at 24 mL/kg volume, 0 cm H2O PEEP, 100/min respiratory rate, and 0.21 inspired oxygen fraction. In the NOX4 inhibitor group, 50 μL anti-GKT 137831 inhibitor was injected intraperitoneally, 2 h after ventilator use. After 5 h of HTV, mice in the ventilator group were euthanized, and their lung tissues were obtained for further analysis. In addition, the relationship between EphA2 (which is related to lung injury) and NOX4 was investigated using EphA2 KO mice, and NOX4 and EphA2 levels in the bronchoalveolar lavage fluid (BALF) of 38 patients with pneumonia were examined.
Results:
Cell counts from BALFs were significantly lower in the NOX4 KO with HTV group (p < 0.01) and EphA2 KO with HTV group (p < 0.001) compared to that in the HTV group. In the NOX4 inhibitor group, cell counts and protein concentrations from BALF were significantly lower than those in the HTV group (both, p < 0.001). In the NOX4 KO group and the NOX4 inhibitor group, EphA2 levels were significantly lower than those in the HTV group (p < 0.001). In patients with respiratory disease, NOX4 and EphA2 levels were significantly higher in patients with pneumonia and patients who received ventilator treatment in the intensive care unit.
Conclusion:
In the VILI model with high tidal volume, NOX4 KO, EphA2 KO or monoclonal antibodies attenuated the VILI. NOX4 and EphA2 levels were significantly higher in patients with pneumonia and especially in mechanical ventilated in the ICU. Inhibition of Nox4 is a potential therapeutic target for the prevention and reduction of VILI.
Insights
Ventilator-induced lung injury (VILI) was reduced in mice lacking NOX4 or treated with a NOX4 inhibitor. Elevated NOX4 and EphA2 levels in pneumonia patients suggest NOX4 as a therapeutic target for VILI.
Area of Science:
- Biomedical Research
- Pulmonary Medicine
- Molecular Biology
Background:
- Mechanical ventilation is crucial for acute respiratory distress syndrome (ARDS) patients but can cause lung damage.
- The role of NOX4 in ventilator-induced lung injury (VILI) requires further investigation.
Purpose of the Study:
- To investigate the protective role of NOX4 knockout (KO) and NOX4 inhibitors in a VILI mouse model.
- To explore the relationship between NOX4, EphA2, and VILI in both animal models and human patients.
Main Methods:
- Utilized NOX4 knockout (KO) and wild-type (WT) mice in a high tidal ventilation (HTV) model.
- Administered a NOX4 inhibitor (anti-GKT 137831) to WT mice undergoing HTV.
- Analyzed bronchoalveolar lavage fluid (BALF) and lung tissues for cell counts, protein concentration, and EphA2 levels.
- Examined NOX4 and EphA2 levels in BALF from pneumonia patients.
Main Results:
- NOX4 KO and NOX4 inhibitor treatments significantly reduced VILI indicators (cell counts, protein) in mice.
- EphA2 KO also attenuated VILI, and NOX4/EphA2 levels were reduced by NOX4 inhibition.
- Elevated NOX4 and EphA2 levels were observed in pneumonia patients, particularly those on mechanical ventilation.
Conclusions:
- NOX4 knockout, EphA2 knockout, or antibody treatment attenuated VILI in a high tidal volume model.
- NOX4 and EphA2 are upregulated in pneumonia patients requiring mechanical ventilation.
- Inhibiting NOX4 presents a potential therapeutic strategy for preventing and mitigating VILI.
