Clarithromycin ameliorates pulmonary inflammation induced by short term cigarette smoke exposure in mice

Dual interleukin-17A/F deficiency protects against acute and chronic response to cigarette smoke exposure in mice

IL-17A and IL-17F are both involved in the pathogenesis of neutrophilic inflammation observed in COPD and severe asthma. To explore this, mice deficient in both Il17a and Il17f and wild type (WT) mice were exposed to cigarette smoke or environmental air for 5 to 28 days and changes in inflammatory cells in bronchoalveolar lavage (BAL) fluid were determined. We also measured the mRNA expression of keratinocyte derived chemokine (Kc), macrophage inflammatory protein-2 (Mip2), granulocyte–macrophage colony stimulating factor (Gmcsf) and matrix metalloproteinase-9 (Mmp9 ) in lung tissue after 8 days, and lung morphometric changes after 24 weeks of exposure to cigarette smoke compared to air-exposed control animals. Macrophage counts in BAL fluid initially peaked at day 8 and again on day 28, while neutrophil counts peaked between day 8 and 12 in WT mice. Mice dual deficient with Il17a and 1l17f showed similar kinetics with macrophages and neutrophils, but cell numbers at day 8 and mRNA expression of Kc, Gmcsf and Mmp9 were significantly reduced. Furthermore, airspaces in WT mice became larger after cigarette smoke exposure for 24 weeks, whereas this was not seen dual Il17a and 1l17f deficient mice. Combined Il17a and Il17f deficiency resulted in significant attenuation of neutrophilic inflammatory response and protection against structural lung changes after long term cigarette smoke exposure compared with WT mice. Dual IL-17A/F signalling plays an important role in pro-inflammatory responses associated with histological changes induced by cigarette smoke exposure.

Baicalin alleviates chronic obstructive pulmonary disease through regulation of HSP72-mediated JNK pathway

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by airway obstruction and progressive lung inflammation. As the primary ingredient of a traditional Chinese medical herb, Baicalin has been previously shown to possess anti-inflammatory abilities. Thus, the current study aimed to elucidate the mechanism by which baicalin alleviates COPD.

METHODS

Baicalin was adopted to treat cigarette smoke in extract-exposed MLE-12 cells after which cell viability and apoptosis were determined. The production of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-8 were determined by enzyme-linked immunoassay. A COPD mouse model was constructed via exposure to cigarette smoke and lipopolysaccharide, baicalin treatment. Lung function and inflammatory cell infiltration were determined and the production of Muc5AC, TNF-α, IL-6, IL-8 in the bronchoalveolar lavage fluid (BALF) was assayed by ELISA. The effect of HSP72 and JNK on COPD following treatment with baicalin was assessed both in vivo and in vitro by conducting loss- and gain- function experiments.

RESULTS

Baicalin improved lung function evidenced by reduction in inflammatory cell infiltration and Muc5AC, TNF-α, IL-6 and IL-8 levels observed in BALF in mice. Baicalin was further observed to elevate cell viability while inhibited apoptosis and TNF-α, IL-6 and IL-8 levels in MLE-12 cells. Baicalin treatment increased HSP72 expression, while its depletion reversed the effect of baicalin on COPD. HSP72 inhibited the activation of JNK, while JNK activation was found to inhibit the effect of baicalin on COPD.

CONCLUSIONS

Baicalin upregulated the expression of HSP72, resulting in the inhibition of JNK signaling activation, which ultimately alleviates COPD.

Cigarette Smoke Exposure to Pig Larynx in an Inhalation Chamber

OBJECTIVES

This study investigated the effects of cigarette smoke exposure on the pig larynx using an inhalation chamber. Specifically, we compared the effects of cigarette smoke exposure from either 3 cigarettes per day (3cd) or 15 cigarettes per day (15cd) for 20 days.

STUDY DESIGN

In vivo prospective design.

METHODS

Female pigs were exposed via an inhalation chamber to cigarette smoke (3R4F research cigarettes) from 3cd (n = 6) or 15cd (n = 6) for 20 days. Outcomes included histopathology of vocal fold and airway tissues; gene expression of interleukins, TNF-α, and VEGF; protein levels of TNF-α and IL-6; and number of coughs recorded in the chamber.

RESULTS

Pigs exposed to cigarette smoke from 15cd exhibited mild vocal fold edema as compared to the 3cd group on histopathological evaluation. There was also minimal inflammation of nasal and tracheal tissue characterized by presence of more granulocytes in the 15cd group compared to the 3cd group. Cough frequency was significantly greater for the 15cd group compared to the 3cd group.

CONCLUSIONS

A custom-designed large animal inhalation chamber successfully challenged pigs repeatedly, to varying levels of cigarette smoke. Future studies will combine such low levels of smoke exposure with other common challenges such as acid reflux to understand the multifactorial causation of laryngeal pathologies.

Management of asthma COPD overlap

OBJECTIVE

To review the latest literature on management approaches to patients with asthma chronic obstructive pulmonary disease (COPD) overlap (ACO).

DATA SOURCES

Studies and reports were identified from the databases of PubMed/Medline and ClinicalTrials.gov from the US National Institutes of Health and the Cochrane Register of Controlled Trials.

STUDY SELECTIONS

Studies on the management of asthma, COPD, and ACO were included in this review.

RESULTS

Patients with asthma COPD overlap tend to have greater morbidity than those with asthma or COPD alone, but the information on the best therapeutic approach to this group of patients is still limited. Current treatment recommendations rely on expert opinions, roundtable discussions, and strategy documents, because most clinical studies in asthma and COPD have excluded patients with ACO. Because of the potential risk described in patients with asthma with the use of long-acting 2 agonist monotherapy, initial therapy for patients with ACO is recommended to include a long-acting bronchodilator in conjunction with inhaled corticosteroids. Long-acting muscarinic antagonists are effective in both asthma and COPD and should be considered in ACO as an add-on treatment. If inhaler therapy is not effective, advanced therapies based on phenotyping and identification of treatable traits may be considered.

CONCLUSION

Few studies have evaluated prospectively therapies in the ACO population, and future studies need to determine best strategies for the treatment of these patients, focusing on targeting its different phenotypes and its treatable traits.

Increased matrix metalloproteinase-9 to tissue inhibitor of metalloproteinase-1 ratio in smokers with airway hyperresponsiveness and accelerated lung function decline

Background

Airway hyperresponsiveness (AHR) is associated with airway inflammation and a rapid decline in lung function and is a predictor of future risk of COPD among smokers. Alveolar macrophages (AMs) from patients with COPD release a greater amount of matrix metalloproteinase (MMP)-9. We hypothesized that the imbalance between MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) is related to AHR in smokers.

Patients and methods

Healthy smokers with AHR (AHR + S) or smokers without AHR (AHR − S; divided according to a methacholine challenge test) and nonsmokers without AHR (AHR − NS) were enrolled. Spirometry was performed during enrollment and repeated after 5 years. Initially, AMs recovered from bronchoalveolar lavage (BAL) fluid were cultured in the presence of p38 mitogen-activated protein kinase (MAPK) inhibitor (SB203580), MAPK kinase (MEK) 1/2 (the MEK of extracellular signal-regulated kinase [ERK] inhibitor, PD98059), or medium alone for 24 h. The release of MMP-9 and TIMP-1 in culture supernatants was measured by enzyme-linked immunosorbent assay.

Results

A greater reduction in forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC), FEV₁ (as a percentage of the predicted value [%pred]), and maximal mid-expiratory flow (MMEF) was observed among AHR + S in the 5-year period. There was a higher proportion of neutrophils and a lower proportion of AMs in BAL fluid recovered from AHR + S. Compared to AMs from AHR − NS and AHR − S, AMs from nonsmokers with AHR (AHR + NS) released more MMP-9 and less TIMP-1, with an increase in MMP-9/TIMP-1 ratios. The MMP-9/TIMP-1 ratio in smokers was positively correlated with the annual decline in FEV₁%pred, FVC%pred, and MMEF%pred. Both SB203580 and PD98059 significantly reduced MMP-9, but not TIMP-1, from AMs of smokers.

Conclusion

AMs of AHR + NS produce excessive MMP-9 over TIMP-1, which may be a predictor of the development of airway obstruction. Inhibition of p38 MAPK and ERK suppresses the generation of MMP-9 by AMs from smokers.

Protective effect of HwangRyunHaeDok-Tang water extract against chronic obstructive pulmonary disease induced by cigarette smoke and lipopolysaccharide in a mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Hwangryunhaedok-tang is an oriental herbal formula treated to cure inflammation and gastric disorders in China, Japan, and Korea. We explored the protective effects of Hwangryunhaedok-tang water extract (HRWE) against airway pathophysiological changes caused by cigarette smoke (CS) and lipopolysaccharide (LPS) in a mouse.

MATERIALS AND METHODS

We performed quantitative analyses of five marker components, namely geniposide, baicalin, coptisine, plamatine, and berberine, using high-performance liquid chromatography. Animals were received CS exposure (1h per day) for 7 days. LPS was administered intranasally on day 4. Mice were received HRWE at dose of 100 or 200mg/kg for 1h before CS exposure.

RESULTS

Treatment with HRWE significantly suppressed the increased inflammatory cell count induced by CS and LPS exposure. In addition, reduction in IL-6, TNF-α and IL-1β in broncho-alveolar lavage fluid (BALF) was observed after HRWE treatment. HRWE not only decreased inflammatory cell infiltration in lung, but also decreased the expression of iNOS, NF-κB and matrix metallopeptidase (MMP)-9 in lung tissues.

CONCLUSION

This study showed that HRWE can attenuate respiratory inflammation caused by CS and LPS exposure. Therefore, HRWE has potential for treating airway inflammatory disease.