Effect of inhaled indomethacin on distilled water-induced airway epithelial cell swelling

Changes in lung sounds during asthma progression in a guinea pig model

BACKGROUND

Lung sound analysis is useful for objectively evaluating airways even in children with asymptomatic asthma. However, the relationship between lung sounds and morphological changes in the airways has not been elucidated. We examined the relationship between lung sounds and chronic morphological changes in the airways during the progression of asthma from onset in guinea pigs.

METHODS

Eleven male guinea pigs were examined; of these, seven were used as asthma models and four as controls. The asthma models were sensitized and repeatedly challenged by inhaling albumin chicken egg. We measured lung sounds and lung function twice a week for 21 weeks. After the final antigen challenge, the lungs were excised for histological examination. We measured the ratio of airway wall thickness to the total airway area and the ratio of the internal area to the total airway area in the trachea, third bronchi, and terminal bronchioles.

RESULTS

Among the lungs sounds, the difference between the two groups was greatest with respect to inspiratory sound intensity. The ratio of airway wall thickness to the total airway area of the terminal bronchioles was greater in the asthma models than in the controls, and it correlated best with the changes in inspiratory sound intensity in the 501-1000-Hz range (r = 0.76, p < 0.003).

CONCLUSIONS

Lung sound intensity in the middle frequency range from 501 to 1000 Hz correlated with peripheral airway wall thickness. Inspiratory sound intensity appeared to be an indicator of morphological changes in small airways in asthma.

Inhaled non-steroid anti-inflammatories for children and adults with bronchiectasis

BACKGROUND

Chronic neutrophilic inflammation, in both the presence and absence of infection, is a feature of bronchiectasis in adults and children. The anti-inflammatory properties of non-steroid anti-inflammatory drugs (NSAIDs) may be beneficial in reducing airway inflammation, thus potentially improving lung function and quality of life in patients with bronchiectasis.

OBJECTIVES

To evaluate the efficacy of inhaled NSAIDs in the management of non-cystic fibrosis bronchiectasis in children and adults:• during stable bronchiectasis; and• for reduction of:∘ severity and frequency of acute respiratory exacerbations; and∘ long-term pulmonary decline.

SEARCH METHODS

We searched the Cochrane Airways Group Trials Register, which includes reports identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL). We also searched the trial registry ClinicalTrials.gov and the World Health Organization (WHO) trial portal. We carried out the latest searches on 22 September 2015.

SELECTION CRITERIA

All randomised controlled trials comparing inhaled NSAIDs versus a control (placebo or usual treatment) in children or adults with bronchiectasis not related to cystic fibrosis.

DATA COLLECTION AND ANALYSIS

We reviewed the results of searches against predetermined criteria for inclusion.

MAIN RESULTS

One small, short-term trial was eligible for inclusion. We included this study of 25 adults with chronic lung disease (only 32% of people included in the trial had bronchiectasis), as the other conditions were linked to development of bronchiectasis, and all were characterised by chronic sputum production. We were not able to obtain separate data for people with a diagnosis of bronchiectasis. We judged that the study was at a high risk of selection bias.The primary outcome (mean difference in control of bronchiectasis severity, quality of life (Qol), cough scores) was not reported in the included study. The single trial in adults reported a significant reduction in sputum production over 14 days for the treatment group (inhaled indomethacin) compared with the placebo group (mean difference (MD) -75.00 g/day; 95% confidence interval (CI) -134.61 to -15.39) and a significant improvement in the Borg Dyspnoea Scale score (MD -1.90, 95% CI -3.15 to -0.65). We noted no significant differences between groups in lung function or blood indices and no reported adverse events.

AUTHORS' CONCLUSIONS

No new studies of adults or children have been conducted since the last version of this review was published. Therefore, final conclusions have not changed. Current evidence is insufficient to support or refute the use of inhaled NSAIDs for the management of bronchiectasis in adults or children. One small trial reported a reduction in sputum production and improved dyspnoea among adults with chronic lung disease who were treated with inhaled indomethacin, indicating that additional studies on the efficacy of NSAIDs for treatment of patients with bronchiectasis are warranted.

Possible contribution of pannexin-1 to ATP release in human upper airway epithelia

Pannexins are a family of transmembrane nonselective channel proteins that participate in the release of ATP into extracellular space. Previous studies have suggested that pannexin-1 (Panx1) may constitute a local autocrine/paracrine system via transmitter ATP in association with the purinergic P2X7 receptor. In this study, we investigate the expressions of Panx1 and P2X7 in human nasal mucosa, together with hypotonic stress-induced ATP release from this tissue. Twenty men and one woman ranging in age from 10 to 82 years with an average age of 44.2 ± 4.4 years participated in the study. Inferior turbinates were collected from patients with chronic hypertrophic rhinitis during endoscopic endonasal surgery. The expressions of Panx1 and P2X7 were examined by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). We also examined hypotonic stress-induced ATP release from the turbinate mucosa and the effects of channel blockers in an ex vivo experiment. Substantial expressions of both proteins were observed in human nasal mucosa. The immunoreactivity for Panx1 was stronger than that for P2X7. The presence of the transcripts of Panx1 and P2X7 was also shown by qRT-PCR. Ten and 100 μmol/L carbenoxolone (a Panx1 channel blocker) significantly inhibited the ATP release from the nasal mucosa, but flufenamic acid (a connexin channel blocker) and gadolinium (a stretch-activated channel blocker) did not. These results indicate the coexistence of Panx1 and P2X7 in, and Panx1-dependent ATP release from, the human nasal mucosa, suggesting the possible participation of these molecules in the physiological functions of the upper airway.

Effect of NSAIDs on Na⁺/H⁺ exchanger activity in rat colonic crypts

Nonsteroidal anti-inflammatory drugs (NSAIDs; 1) are widely recommended for several acute and chronic conditions. For example, both indomethacin and aspirin are taken for pain relief. Aspirin is also used for prevention of myocardial infarction, and indomethacin can be administered orally or as a suppository for patients with rheumatoid disease and other chronic inflammatory states. However, use of NSAIDs can cause damage to the mucosal barrier surrounding the gastrointestinal (GI) tract, increasing the risk of ulcer formation. While microencapsulation of NSAIDs has been shown to reduce upper GI injury, sustained release in the lower GI tract and colon may cause epithelial erosion due to increased acidification. The use of suppositories has also been linked to rectal and lower GI bleeding. In this study, we investigated the role of NSAIDs aspirin and indomethacin on Na⁺/H⁺ exchanger (NHE) activity in rat colonic crypts. By comparing average rates of pH recovery between control and NSAID perfusion runs, we were able to determine that both aspirin and indomethacin increase hydrogen extrusion into the colonic lumen. Through treatment with 5-ethylisopropyl amiloride (EIPA), amiloride, and zoniporide dihydrochloride, we further demonstrated that indomethacin specifically enhances proton excretion through regulation of apical NHE-3 and NHE-2 and to a lesser extent on basolateral NHE-1 and NHE-4. Our results suggest that clinical exposure to NSAIDs may affect colonic tissue at the site of selected NHE isoforms, resulting in modulation of transport and barrier function.

Inhaled non-steroid anti-inflammatories for children and adults with bronchiectasis

BACKGROUND

Chronic neutrophilic inflammation, both in the presence and absence of infection, is a feature of bronchiectasis in adults and children. The anti-inflammatory properties of non-steroid anti-inflammatory drugs (NSAIDs) may be beneficial in reducing airway inflammation and thus potentially improve lung function and quality of life in patients with bronchiectasis.

OBJECTIVES

To evaluate the efficacy of inhaled NSAIDs in the management of non-cystic fibrosis bronchiectasis in children and adults.

SEARCH STRATEGY

We searched the Cochrane Airways Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 3), MEDLINE, OLDMEDLINE and EMBASE databases. The latest searches were carried out in October 2009

SELECTION CRITERIA

All randomised controlled trials comparing inhaled NSAIDs to a control group (placebo or usual treatment) in children or adults with bronchiectasis not related to cystic fibrosis.

DATA COLLECTION AND ANALYSIS

We reviewed the results of the searches against pre-determined criteria for inclusion.

MAIN RESULTS

One small, short-term trial was eligible for inclusion. We included this study of 25 adults with chronic lung disease (including bronchiectasis) as the other conditions were linked to development of bronchiectasis and all had chronic sputum production.The single trial in adults reported a significant reduction in sputum production over 14 days in the treatment group (inhaled indomethacin) compared to placebo (difference -75.00 g/day; 95% CI -134.61 to -15.39) and a significant improvement in a dyspnoea score (difference -1.90; 95% CI -3.15 to -0.65). There was no significant difference between groups in lung function or blood indices. No adverse events were reported.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to support or refute the use of inhaled NSAIDs in the management of bronchiectasis in adults or children. One small trial reported a reduction in sputum production and improved dyspnoea in adults with chronic lung disease who were treated with inhaled indomethacin, indicating that further studies on the efficacy of NSAIDs in treating patients with bronchiectasis are warranted.

Aspirin and indomethacin reduce lung inflammation of mice exposed to cigarette smoke

Neutrophil accumulation response to cigarette smoke (CS) in humans and animal models is believed to play an important role in pathogenesis of many tobacco-related lung diseases. Here we evaluated the lung anti-inflammatory effect of aspirin and indomethacin in mice exposed to CS. C57BL/6 mice were exposed to four cigarettes per day during 4 days and were treated i.p. with aspirin or indomethacin, administered each day 1h before CS exposure. Twenty four hours after the last exposure, cells and inflammatory mediators were assessed in bronchoalveolar lavage (BAL) fluid and the lungs used for evaluation of lipid peroxidation, p38 mitogen-activated protein kinase (MAPK) phosphorylation and nuclear transcription factor kappaB (NF-kappaB) activation. Exposure to CS resulted in a marked lung neutrophilia. Moreover, the levels of oxidative stress-related lipid peroxidation, prostaglandin E(2) (PGE(2)), interleukin 1beta (IL-1beta), monocyte chemotactic protein 1 (MCP-1), and activated NF-kappaB and p38 MAPK were greatly increased in CS group. Aspirin or indomethacin treatment led to a significant reduction of neutrophil influx, but only aspirin resulted in dramatic decrease of inflammatory mediators. Moreover, both drugs reduced lung p38 MAPK and NF-kappaB activation induced by CS. These results demonstrate that short-term CS exposure has profound airway inflammatory effects counteracted by the anti-inflammatory agents aspirin and indomethacin, probably through COX-dependent and -independent mechanisms.

Effect of Inhaled Histamine on Airway Epithelial Cell Swelling in Ozone-Exposed Guinea Pigs

BACKGROUND

It has been reported that histamine stimulates ion channels on airway epithelial cells and induces changes in osmolarity and the ion composition of the periciliary field of airway epithelia.

OBJECTIVE

To investigate the effect of inhaled histamine on epithelial cell swelling, we studied the role of airway epithelial cells under histamine inhalation challenge in an animal model of airway inflammation using ozone exposure.

METHOD

After exposure to 3.0 ppm ozone for 2 h, guinea pigs were anesthetized and tracheostomized, and then, lung resistance (R(L)) was measured. Histamine inhalation challenge and histological examination were performed.

RESULT

The values of R(L) before histamine inhalation in the control group and the ozone-exposed group were 0.26 +/- 0.11 and 0.45 +/- 0.34 cm H(2)O/s, respectively. R(L) increased significantly after histamine inhalation both in the control and the ozone-exposed groups. The threshold of histamine (PC(200)) in the ozone-exposed group was significantly lower than that in the control group. A significant swelling of the epithelial cells after histamine inhalation was observed both in the control and the ozone-exposed groups, with a greater increase in the ozone-exposed group compared with the control group. However, no change in wall thickness was observed in the histamine/antihistamine or the ozone/histamine/antihistamine group.

CONCLUSION

Our results suggest the possibility that the airway epithelial cell swelling plays a role in the increase in R(L) after histamine inhalation, especially in the presence of airway inflammation.

Pulmonary function and structure following mild preterm birth in lambs

Our objective was to determine whether postnatal respiratory function, lung growth, and lung structure are affected by preterm birth which did not require neonatal respiratory support. Two groups of preterm (P) lambs were delivered 2 weeks before term, at 133 days of gestational age (GA). Tissue was collected at term equivalent age (TEA, 147 days GA) in one P group and at 6 weeks post-TEA in the other. Tissue was also collected from control (C) lambs soon after term birth (TEA) and at 6 weeks post-TEA. Lung function was assessed at TEA and 6 weeks post-TEA. Respiratory system compliance (Crs/kg BWT) was not different between P and C groups at TEA, but was higher (P = 0.02) in P lambs at 6 weeks post-TEA. Pulmonary resistance was 62% higher in P lambs than controls (P = 0.07) at TEA, and remained higher at 6 weeks post-TEA. Lung weights (wet and dry) were greater (P < 0.05) in preterm animals at both ages; when adjusted for body weight, only dry lung weight remained higher at 6 weeks post-TEA. Alveoli were more numerous (P = 0.05) and smaller (P = 0.05) in preterm lambs compared to controls at both ages. Alveolar septa were 33% thicker and the blood-air barrier was 26% thicker in P lambs than in controls at TEA, and remained thicker at 6 weeks post-TEA. In P lambs, the airway epithelium was thicker at TEA and 6 weeks post-TEA. At TEA, pulmonary tropoelastin expression was 27% lower in P lambs. At 6 weeks post-TEA, dry lung weight and lung protein content were approximately 50% greater in preterm lambs than in controls (P < 0.05), whereas lung DNA, elastin, and collagen contents were similar in the two groups. We conclude that mild preterm birth per se leads to both transient and persistent changes in lung development. Persistent increases in lung protein content and in the thickness of the airway epithelium, and a greater number of smaller alveolar, may alter later lung function.

Aerosolized nanogram quantities of plasmid DNA mediate highly efficient gene delivery to mouse airway epithelium

The lung is an important target of gene therapeutic interventions. In contrast to intratracheal instillation, inhalation would be the most practical route of administration in clinical applications. Here we show that aerosolized nanogram quantities of pDNA complexed to PEI (350 ng) yielded transfection levels 15-fold higher than a 140-fold higher dose (50 microg) of the same vector applied directly to the lungs of mice via intratracheal intubation. An important efficacy parameter is the osmolarity of the aerosol and not biophysical properties of the nebulized vector. Vectors formulated and nebulized in hypoosmotic distilled water yielded 57- and 185-fold higher expression levels than those in isotonic 5% glucose or Hepes-buffered saline, respectively. Pretreatment of mice with nebulized indomethacin, which prevents water-induced airway alteration, resulted in lower gene expression, whereas pretreatment with EGTA or polidocanol, which modulate tight-junction activity, had no effect. These results, together with histological analysis of regional lung deposition and gene expression, suggest that a temporary water-induced hypoosmotic shock permeabilizes the epithelium sufficiently to allow vector uptake. The so far observed inefficiency of nonviral gene delivery to the airways may be the result of an inappropriate method of vector administration.

Effect of ozone exposure on intracellular glutathione redox state in cultured human airway epithelial cells

Intracellular oxidation and reduction (redox state) correspond closely to the surrounding environment. Most environmental factors affecting this balances such as oxidants, ultraviolet light, radioactive emissions, infections, and allergic reactions represent oxidative stress upon cells. We examined intracellular redox state after oxidative stress upon cultured human airway epithelial cells (Calu-3) by measuring reduced (GSH) or oxidized (GSSG) glutathione. We studied cytokine production, which is related to glutathione redox regulation, in response to ozone and also evaluated the effect of pretreatment with an ethyl ester of reduced glutathione (GSH-OEt) on cytokines. Ozone exposure (3.0 ppm, 3 min) time-dependently changed the redox state, while increasing production of interleukin(IL)-8 and IL-6, mRNA and protein. Treatment with GSH-OEt before ozone suppressed IL-8, but stimulated IL-6 production. Thus, oxidative stress affects intracellular glutathione redox state, in airway epithelial cells, activating signals to increase production of cytokine, modulation that may exacerbate respiratory symptoms.