Animal model of cigarette smoke (CS) –induced chronic obstructive pulmonary disease (COPD) is the primary testing methodology for drug therapies and studies on pathogenic mechanisms of disease. However, researchers have rarely run simultaneous or side-by-side tests of whole-body and nose-only CS exposure in building their mouse models of COPD. We compared and evaluated these two different methods of CS exposure, plus airway Lipopolysaccharides (LPS) inhalation, in building our COPD mouse model. Compared with the control group, CS exposed mice showed significant increased inspiratory resistance, functional residual capacity, right ventricular hypertrophy index, and total cell count in BALF. Moreover, histological staining exhibited goblet cell hyperplasia, lung inflammation, thickening of smooth muscle layer on bronchia, and lung angiogenesis in both methods of CS exposure. Our data indicated that a viable mouse model of COPD can be established by combining the results from whole-body CS exposure, nose-only CS exposure, and airway LPS inhalation testing. However, in our study, we also found that, given the same amount of particulate intake, changes in right ventricular pressure and intimal thickening of pulmonary small artery are a little more serious in nose-only CS exposure method than changes in the whole-body CS exposure method.

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterized by abnormal inflammation, persistent and progressive lung function decline. The anti-inflammatory actions of tanshinone IIA, which is the most important active component from Chinese herbal medicine Danshen, have been well studied. However, it remains unknown whether sodium tanshinone IIA sulfonate (STS) protects against the development of COPD. Here we found that STS inhalation (5 mg/kg, 30 min per session, twice a day) significantly attenuated lung function decline, airspace enlargement, mucus production, bronchial collagen deposition, inflammatory responses and oxidative stress caused by cigarette smoke (CS) and lipopolysaccharide (LPS) exposures in mice. Moreover, treatment with STS (10 μg/ml) reduced CS extract (CSE)-induced IL-6 and IL-8 secretion in human bronchial epithelial (16HBE) cells. The anti-inflammatory actions of STS were associated with inhibition of ERK1/2 and NF-κB activations. Interestingly, STS inhibited CS-induced reduction of cystic fibrosis transmembrane conductance regulator (CFTR) in mouse lungs and in 16HBE cells. Treatment with a specific CFTR inhibitor CFTR-Inh172 augmented CSE-induced ERK1/2 and NF-κB-dependent inflammatory responses, but abolished the inhibitory action of STS on IL-6 and IL-8 secretion in 16HBE cells. These results demonstrate that CS-induced COPD and down-regulation of CFTR are prevented by STS.

Aberrant activation of hypoxia-inducible factor (HIF)-1α is frequently encountered and promotes oxidative stress and inflammation in chronic obstructive pulmonary disease (COPD). The present study investigated whether sodium tanshinone IIA sulfonate (STS), a water-soluble derivative of tanshinone IIA, can mediate its effect through inhibiting HIF-1α–induced oxidative stress and inflammation in cigarette smoke (CS)-induced COPD in mice. Here, we found that STS improved pulmonary function, ameliorated emphysema and decreased the infiltration of inflammatory cells in the lungs of CS-exposed mice. STS reduced CS- and cigarette smoke extract (CSE)-induced upregulation of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the lungs and macrophages. STS also inhibited CSE-induced reactive oxygen species (ROS) production, as well as the upregulation of heme oxygenase (HO)-1, NOX1 and matrix metalloproteinase (MMP)-9 in macrophages. In addition, STS suppressed HIF-1α expression in vivo and in vitro, and pretreatment with HIF-1α siRNA reduced CSE-induced elevation of TNF-α, IL-1β, and HO-1 content in the macrophages. Moreover, we found that STS inhibited CSE-induced the phosphorylation of ERK, p38 MAPK and JNK in macrophages, and inhibition of these signaling molecules significantly repressed CSE-induced HIF-1α expression. It indicated that STS inhibits CSE-induced HIF-1α expression likely by blocking MAPK signaling. Furthermore, STS also promoted HIF-1α protein degradation in CSE-stimulated macrophages. Taken together, these results suggest that STS prevents COPD development possibly through the inhibition of HIF-1α signaling, and may be a novel strategy for the treatment of COPD.