Background: Chronic obstructive pulmonary disease (COPD) is a health problem that results in death, commonly due to the development of pulmonary hypertension (PH). Here, by utilizing a mouse model of intratracheal elastase-induced emphysema that presents three different phases of COPD, we sought to observe whether budesonide/glycopyrronium/formoterol fumarate (BGF) triple therapy could prevent COPD-PH in addition to ameliorating COPD progression.
Methods: We utilized intratracheal elastase-induced emphysema mouse model and performed experiments in three phases illustrating COPD progression: inflammatory (1 day post-elastase), emphysema (3 weeks post-elastase) and PH (4 weeks post-elastase), while treatments of BGF and controls (vehicle, one-drug, and two-drug combinations) were started in prior to elastase instillation (inflammatory phase), at day 7 (emphysema), or at day 14 (PH phase). Phenotype analyses were performed in each phase. In vitro, A549 cells or isolated mouse lung endothelial cells (MLEC) were treated with TNFα with/without BGF treatment to analyze NFκB signaling and cytokine expression changes.
Results: We observed significant reductions in the proinflammatory phenotype observed in the lungs and bronchoalveolar lavage fluid (BALF) 1 day after elastase administration in mice treated with BGF compared with that in mice administered elastase alone (BALF neutrophil percentage, p = 0.0011 for PBS/Vehicle vs. PBS/Elastase, p = 0.0161 for PBS/Elastase vs. BGF). In contrast, only BGF treatment significantly ameliorated the elastase-induced emphysematous lung structure and desaturation after three weeks of elastase instillation (mean linear intercept, p = 0.0156 for PBS/Vehicle vs. PBS/Elastase, p = 0.0274 for PBS/Elastase vs. BGF). Furthermore, BGF treatment prevented COPD-PH development, as shown by improvements in the hemodynamic and histological phenotypes four weeks after elastase treatment (right ventricular systolic pressure, p = 0.0062 for PBS/Vehicle vs. PBS/Elastase, p = 0.027 for PBS/Elastase vs. BGF). Molecularly, BGF acts by inhibiting NFκB-p65 phosphorylation and subsequently decreasing the mRNA expression of proinflammatory cytokines in both alveolar epithelial and pulmonary endothelial cells.
Conclusion: Our results collectively showed that BGF treatment could prevent PH in addition to ameliorating COPD progression via the inhibition of inflammatory NFκB signaling.
Keywords: Budesionde; Chronic obstructive pulmonary disease; Formoterol fumarate; Glycopyrronium; NFκB; Pulmonary hypertension.
© 2022. The Author(s).