Changes in alveolar macrophage enzyme content and activity in smokers and patients with chronic obstructive lung disease

An influx of polymorphonuclear and mononuclear cells into the lungs of smokers and patients with chronic obstructive lung disease (COLD) is thought to be an important factor in the development of pulmonary emphysema. Next to the synthesis and release of toxic oxygen radicals and mediators, an enhanced production and activity of proteolytic enzymes could play an important role in the pathogenesis of emphysema. In the present study changes were investigated in the broncho-alveolar lavage (BAL) fluid and BAL-cells, especially in alveolar macrophages. Pulmonary lavages were performed in the middle lobe with sterile saline of 37 degrees C in individuals, who could be divided on the basis of their history and lung function into normal/nonsmokers, normal/smokers, COLD-patients/nonsmokers and COLD-patients/smokers. Alveolar macrophages obtained by BAL were stained for different lysosomal enzymes. Isolated BAL-fluid and BAL-cells were assayed for elastolytic activity. In alveolar macrophages of smoking COLD-patients significantly more beta-glucuronidase could be demonstrated. Elastolytic activity changed with smoking habits, suggesting an enhanced release of elastolytic enzymes. No correlation was found between elastolytic activity and the amount of polymorphonuclear cells in the BAL-fluid. From these results it may be concluded that enzymes from alveolar macrophages play a more important role in the pathogenesis of emphysema than those from polymorphonuclear cells.     

Respiratory effects of cocaine freebasing among habitual cocaine users.

Smoking of alkaloidal cocaine ("crack") has become increasingly prevalent in our society. Recent evidence suggests that crack smoking can cause acute respiratory symptoms, abnormalities in lung function and, in some instances, severe, life-threatening acute lung injury. To evaluate further the relationship between frequent cocaine smoking and respiratory symptoms and lung dysfunction, we studied a sample of 177 heavy, habitual smokers of freebase cocaine (mean 6.6 gm/wk for an average of 27 months) with or without concomitant smoking of tobacco and/or marijuana. Results in this sample were compared with those in a control sample of 75 age-, sex- and race-matched nonsmokers of cocaine who did or did not also smoke tobacco and/or marijuana. After controlling for the use of other smoked substances, heavy, habitual cocaine smoking was associated with the following: (1) a high frequency of acute respiratory symptoms (cough, black sputum, chest pain) in temporal association with freebase use; (2) an obstructive ventilatory abnormality involving the large airways; and (3) a mild but significant impairment in the diffusing capacity of the lung. These findings suggest that heavy, habitual crack smoking produces (1) respiratory tract injury manifested by acute respiratory symptoms and evidence of chronic airflow obstruction in large airways, and (2) an abnormality in diffusion of gas at the alveolar-capillary level. The mechanism of the diffusion defect is unknown but could reflect damage to the alveolar-capillary membrane. Further study of the magnitude, persistence, reversibility, mechanism and clinical significance of the abnormality in diffusing capacity is needed.     

Respiratory Effects of Cocaine Freebasing Among Habitual Cocaine Users

Smoking of alkaloidal cocaine ("crack") has become increasingly prevalent in our society. Recent evidence suggests that crack smoking can cause acute respiratory symptoms, abnormalities in lung function and, in some instances, sever, life-threatening acute lung unjury. To evalute further the relationship between frequent cocaine smoking and respiratory symptoms and lyng dysfunction, we studied a sample of 177 heavy, habitual smokers of freebase cocaine (mean 6.6 gm/wk for an average of 27 months) with or without concomitant smoking of tobacco and/or marijuana. Results in this sample were compared with those in a control sample of 75 age-, sex- and race-matched nonsmokers of cocaine who did or did not also smoke tobacco and/or marijuana. After controlling for the use of other smoked substances, heavy, habitual cocaine smoking was associated with the following: (1) a high frequency of acute respiratory symptoms (cough, black sputum, chest pain) in temporal association with freebase use; (2) an obstructive ventilatory abnormality involving the large airways; and (3) a mild but significant impairment in the diffusing capacity of the lung. These findings suggest that heavy, habitual crack smoking produces (1) respiratory tract injury manifested by acute respiratory symptoms and evidence of chronic airflow obstruction in large airways, and (2) an abnormality in diffusion of has at the alveolar-capillary level. The mechanism of the diffusion defect is unknown but could reflect damage to the alveolar-capillary membrane. Further study of the magnitude, persistence, reversibility, mechanism and clinical significance of the abnormality in diffusing capacity is needed.     

OZONE EXPOSURE AND THE PRODUCTION OF REACTIVE OXYGEN SPECIES BY BRONCHOALVEOLAR CELLS IN HUMANS

Exposure to ozone injures respiratory epithelium, and the mechanisms may involve the generation of reactive oxygen species (ROS). This study tested the hypothesis that ozone exposure increases the airway burden of ROS to a greater degree in smokers than nonsmokers, and that this effect is independent of ozone-induced changes in spirometry. Healthy subjects were selected as either responders (decrement in FEV₁ > 15%) or non responders (decrement in FEV₁ < 5%) to ozone; each underwent 2 exposures to ozone and 1 to air, with bronchoalveolar lavage (BAL) performed 30 min (early) and 18 h (late) after exposure. Release of superoxide anion (O₂^-) was used as a measure of ROS release by all BAL cells, and flow cytometry was used to detect ROS production in alveolar macrophages (AM) only. Recovery of AM was approximately threefold greater in smokers than nonsmokers. Unstimulated, but not stimulated, cells obtained by BAL from smokers released approximately twofold greater amounts of O₂^- than cells from non smokers, both early and late after ozone exposure (p = .012 and p = .046, respectively). Stimulated, but not unstimulated, ROS generation by AM from smokers increased following ozone exposure, but the ozone effect was not significant. ROS production by AM decreased in nonsmokers (air vs. ozone late, p     

Increased expression of CD4+IL-17+ cells in the lung tissue of patients with stable chronic obstructive pulmonary disease (COPD) and smokers

CD4⁺IL-17⁺ cells have an important role in controlling immune and inflammatory reactions. The authors of the present study hypothesize that these cells may be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). To characterize the frequency of CD4⁺IL-17⁺ cells in the lung alveolar walls, small airways and muscular pulmonary arteries of nonsmokers, smokers with normal lung function and COPD patients, CD4⁺IL-17⁺ cell number was assessed using double immunofluorescence staining, and IL-17 and IL-21 expression were measured using real-time quantitative PCR in the peripheral lung tissues of 10 nonsmokers, 10 smokers with normal lung function and 10 smokers with stable COPD. In the lung alveolar walls, the number of CD4⁺IL-17⁺ cells was increased in COPD patients compared with nonsmokers and in normal smokers compared with nonsmokers. In the small airways, the CD4⁺IL-17⁺ cell numbers were higher in COPD patients than in normal smokers and nonsmokers. A positive correlation was observed between CD4⁺IL-17⁺ cell expression and pathological changes in the lung tissue. In the small airways, the number of CD4⁺IL-17⁺ cells was positively correlated with airflow limitations. The IL-17 mRNA levels in lung tissues were increased in COPD patients and normal smokers compared with nonsmokers. Increased CD4⁺IL-17⁺ cell number in lung tissue is involved in chronic inflammation of the lungs and parallels lung injury aggravation in COPD patients and in smokers without airway limitations. These findings contribute to a better understanding of CD4⁺ cell-related pathogenesis in COPD.     

Bleomycin increases superoxide anion generation by pig peripheral alveolar macrophages

Pulmonary fibrosis is the major toxic effect of bleomycin chemotherapy; however, the molecular mechanisms of the pathological process are unknown. Since alveolar macrophages produce toxic oxygen metabolites and these can damage lung cells, the effect of bleomycin on superoxide anion production was investigated in subpopulations of pig alveolar macrophages. Cells were lavaged from the lung and separated into three subpopulations according to their density. Their capacity to generate superoxide anions increased the more distally they were located. Bleomycin (5.0 milliunits/ml) increased the rate of superoxide production by 75 +/- 24% in dense alveolar macrophages located in the lung periphery. Hydrocortisone (10.0 micrograms/ml) inhibited this superoxide production by 33 +/- 10%. Results from this study suggest that an excess production of superoxide anions by alveolar macrophages may be the underlying cause of bleomycin pulmonary toxicity.     

Depressant effects of ambroxol and erdosteine on cytokine synthesis,granule enzyme release,and free radical production in rat alveolar macrophages activated by lipopolysaccharide

The present study examined the effects of ambroxol and erdosteine, bronchial expectorants, on the cytokine synthesis, granule enzyme release, and free radical production in rat alveolar macrophages activated by lipopolysaccharide. Ambroxol and erdosteine significantly decreased the production of tumour necrosis factors-alpha, interleukin-1beta, and interleukin-6 in alveolar macrophages activated by lipopolysaccharide. These drugs significantly reduced the production of superoxide anion, hydrogen peroxide, and nitric oxide and the release of acid phosphatase and lysozyme in lipopolysaccharide-activated macrophages. Ambroxol and erdosteine showed no scavenging effect on superoxide anion and hydrogen peroxide, whereas both drugs effectively decomposed nitric oxide. The results show that ambroxol and erdosteine may inhibit the responses, including cytokine synthesis and free radical production, in rat alveolar macrophages activated by lipopolysaccharide. Unlike the production of reactive oxygen species, the inhibitory effect of ambroxol and erdosteine on the production of nitric oxide in lipopolysaccharide-activated alveolar macrophages may be accomplished by a scavenging action on the species and inhibition of the respiratory burst.     

Daily patterns of alcohol, cigarette, and marijuana use in adolescent smokers and nonsmokers

Timeline followback (TLFB) methodology was used to assess the daily use of cigarettes, alcohol, and marijuana in adolescent cigarette smokers and nonsmokers over the prior 30 days. Adolescent smokers reported more frequent daily use of both alcohol and marijuana than nonsmokers did. Of those smokers and nonsmokers who drank alcohol and used marijuana, smokers reported more frequent daily use of alcohol, but not marijuana. In examining daily use patterns, there were very few instances when adolescent smokers used alcohol but did not smoke cigarettes, and smokers used marijuana alone on more days than alcohol alone. One-fifth of the adolescent smokers used all three substances on the same day in the past month. There were no significant differences in the patterns of alcohol and marijuana use between female and male smokers, regardless of age. Implications for clinical interventions and future research are discussed.     

Depressant Effects of Ambroxol and Erdosteine on Cytokine Synthesis,Granule Enzyme Release,and Free Radical Production in Rat Alveolar Macrophages Activated by Lipopolysaccharide

Abstract: The present study examined the effects of ambroxol and erdosteine, bronchial expectorants, on the cytokine synthesis, granule enzyme release, and free radical production in rat alveolar macrophages activated by lipopolysaccharide. Ambroxol and erdosteine significantly decreased the production of tumour necrosis factors‐α, interleukin‐1β, and interleukin‐6 in alveolar macrophages activated by lipopolysaccharide. These drugs significantly reduced the production of superoxide anion, hydrogen peroxide, and nitric oxide and the release of acid phosphatase and lysozyme in lipopolysaccharide‐activated macrophages. Ambroxol and erdosteine showed no scavenging effect on superoxide anion and hydrogen peroxide, whereas both drugs effectively decomposed nitric oxide. The results show that ambroxol and erdosteine may inhibit the responses, including cytokine synthesis and free radical production, in rat alveolar macrophages activated by lipopolysaccharide. Unlike the production of reactive oxygen species, the inhibitory effect of ambroxol and erdosteine on the production of nitric oxide in lipopolysaccharide‐activated alveolar macrophages may be accomplished by a scavenging action on the species and inhibition of the respiratory burst.     

Decreased serum cotinine levels in smokers of both tobacco and marijuana as compared with smokers of tobacco only

Serum and salivary cotinine levels were determined in tobacco smokers (n=125) tobacco (n=47) or who smoked both marijuana and tobacco (n=78) as part of a field study of the pulmonary effects of heavy, habitual use of marijuana alone or with tobacco. After adjustment for current daily amount of tobacco use and time since the last tobacco cigarette was smoked, the smokers of both marijuana and tobacco were found to have lower levels of cotinine then those who smoked only tobacco, in serum [258±113 ng/ml (S.D.) and 332±109, respectively; P=0.003] and in saliva (331±170 and 395±170, respectively; P=0.058). Serum cotinine showed a significantly negative relationship to the daily amount of marijuana currently smoked (p=0.026). Possible explanations include inhibition by marijuana component(s) of the enzymes that participate in the conversion of nicotine to cotinine, differences in nicotine absorption patterns between the two groups of tobacco smokers, and acceleration of cotinine metabolism by marijuana smoking. Carefully controlled pharmacokinetic studies, not possible in a large-scale survey such as this one, are required both to confirm the differences in blood cotinine levels observed between the dual smokers of tobacco only and to define more clearly nicotine-marijuana interactions.     

Changes in the broncho-alveolar lavage fluid in smokers and patients with chronic obstructive lung disease

Direct contact of the cells normally present in the bronchial lumen, such as alveolar macrophages, with air pollutants (e.g. cigarette smoke) can lead to the activation of these cells. This activation is beneficial for the cleaning task these cells have in the bronchial tree, but also leads to the release of chemotactic substances, toxic oxygen radicals, enzymes and mediators responsible for bronchial obstruction. As a first step in these processes, an enhanced chemotactic activity can attract neutrophils to the bronchial lumen, where they help by cleaning the lungs from possible dangerous intruders, but can also cause damage to the normal lung architecture. In the present study concerned with the pathogenesis of chronic obstructive lung disease (COLD), broncho-alveolar lavage (BAL) was performed in 35 individuals, who could be divided on he basis of their history and lung function into normal/nonsmokers, normal/smokers, COLD-patients/nonsmokers and COLD-patients/smokers. Neutrophilic chemotactic activity was assayed using Boyden chambers where the patients' own neutrophils were tested. More neutrophils and more neutrophilic chemotactic activity were found in the BAL-fluid of the smokers and COLD-patients. A correlation was demonstrated between the amount of chemotactic activity released during the incubation of cells obtained by BAL and the airway resistance or the airway conductance. These data suggest an enhanced chemotactic activity as one of the initiating factors in the pathogenesis of chronic obstructive lung disease.     

Adolescent tobacco use and substance abuse treatment outcomes

This study investigated the relationship between cigarette-smoking status and 12-month alcohol and marijuana treatment outcomes in a sample of 1,779 adolescents from the Drug Abuse Treatment Outcomes Study for Adolescents. Participants were classified into four groups based on change in cigarette-smoking status from intake to the 12-month follow-up: persistent smokers, nonsmokers, quitters, and smoking initiators. Logistic regression was used to predict likelihood of relapse to alcohol, marijuana, and other drugs after controlling for intake levels and demographic/treatment characteristics. Results found persistent smokers and smoking initiators to have significantly greater odds of alcohol and marijuana relapse compared with quitters. Furthermore, persistent smokers and smoking initiators were also found to have distinctively shorter periods to marijuana relapse at follow-up. Implications for the implementation of tobacco cessation treatment in the context of substance abuse treatment for adolescents are discussed.     

Smokers have reduced nitric oxide production by conducting airways but normal levels in the alveoli

Air exhaled by cigarette smokers contains reduced amounts of nitric oxide (NO). Measurement of NO at different expiratory flow rates permits calculation of NO production by the conducting airways (Vaw(NO)) and alveolar concentration of NO (P(ALV)). An independent measurement of diffusing capacity of the alveolar compartment (D(LNO)) multiplied by P(ALV) allows calculation of NO production by the alveoli (V(LNO)). Twelve asymptomatic cigarette smokers and 22 age-matched nonsmokers had measurements of D(LNO) and expired NO at constant expiratory flow rates varying from 60 to 1500 ml/s. Vaw(NO) in smokers was only 22 +/- 11 nl/min (mean +/- standard deviation, SD) compared to 70 +/- 37 nl/min in nonsmokers (p < .0001). In contrast, V(LNO) showed no significant difference (smokers: 203 +/- 104 nl/min, nonsmokers: 209 +/- 74 nl/min, p = .86). These data show that the diminished NO expired by smokers results from diminished NO production by the tissues of the conducting airways but normal values produced by the alveoli.     

Resveratrol impairs the release of steroid-resistant cytokines from bacterial endotoxin-exposed alveolar macrophages in chronic obstructive pulmonary disease

Airway inflammation in chronic obstructive pulmonary disease (COPD) is believed to be insensitive to corticosteroids. However, corticosteroids are recommended in COPD (GOLD stages III, IV) with frequent exacerbations. Resveratrol has anti-inflammatory properties and could be an alternative to corticosteroids in COPD therapy. We investigated the effect of dexamethasone versus resveratrol on the release of COPD-related inflammatory mediators (IL-6, IL-8, GM-CSF and MCP-1) and matrix-metalloprotease-9 (MMP-9) from alveolar macrophages exposed to gram-negative bacterial endotoxin (lipopolysaccharide, LPS). We compared never-smokers, current smokers without airway obstruction and current smokers with COPD. The cytokines and MMP-9 were measured in cell culture supernatants with ELISA. The release of IL-8 and MMP-9 from LPS-exposed alveolar macrophages was increased in COPD, the release of GM-CSF and IL-6 was decreased in COPD and the release of MCP-1 was without differences between the cohorts. Dexamethasone impaired the release of all cytokines and MMP-9 from LPS-exposed alveolar macrophages of all cohorts, but for IL-8 and GM-CSF this effect was reduced in COPD. In alveolar macrophages of COPD, there was an almost complete reduction in IL-6 release but only a partial reduction in IL-8, GM-CSF, MCP-1 and MMP-9 release demonstrating a partial corticosteroid-insensitivity. In contrast, resveratrol almost completely reduced the release of all cytokines and MMP-9 without significant differences between the cohorts. Our data provide evidence for a corticosteroid resistance of alveolar macrophage-dependent inflammatory responses induced by gram-negative bacteria in COPD and thus question the utility of corticosteroids in COPD therapy. Instead, resveratrol may prove an alternative.     

Oxidants in the gas phase of cigarette smoke pass through the lung alveolar wall and raise systemic oxidative stress

Cigarette smoking-induced oxidative stress plays a key role in the pathogenesis of atherosclerosis in smokers. Aqueous cigarette smoke extract (CSE) contains stable oxidants, peroxynitrite-like reactants, which have the ability to oxidize and nitrate low-density lipoprotein (LDL). We examined whether oxidants in CSE can penetrate into the blood through the lung alveolar wall and cause oxidative vascular injury. The oxidants in CSE and sodium peroxynitrite could easily pass through the reconstituted basement membrane. When CSE or sodium peroxynitrite solution was infused into the alveolar air space of an isolated rat lung mounted in tyrosine solution, CSE gradually increased the 3-nitrotyrosine levels in the external tyrosine solution while sodium peroxynitrite caused a rapid increase. CSE did not activate the rat alveolar macrophages. When rats were acutely exposed to the gas phase of cigarette smoke from which tar and nicotine had been removed, both serum levels of 3-nitrotyrosine and 8-hydroxy-2'-deoxyguanine, oxidative stress markers, rapidly increased. Our results demonstrate that relatively stable oxidants in CSE can pass through the pulmonary alveolar wall into the blood and induce systemic oxidative stress, which most likely facilitates oxidative modification of LDL and endothelial dysfunction, explaining early key events in the development of atherosclerosis.     

Decreased single breath carbon monoxide diffusing capacity in cocaine freebase smokers

The authors performed pulmonary function tests on 10 chronic cocaine freebase smokers. Testing occurred at least 2 weeks after stopping cocaine use. Mean single breath carbon monoxide diffusing capacity (DLCOSB) was significantly reduced (P less than 0.05) in the cocaine smokers when compared with a control group of non-smokers and non-drug users. All other parameters of lung function were normal. Since most of the cocaine smokers also smoked tobacco, the observed abnormality may have been due to an additive effect of the 2 substances. The authors conclude that smoking cocaine may damage the gas exchange surface of the lung.     

Association between cytochrome P450 3A5 polymorphism and the lung function in Saskatchewan grain workers

OBJECTIVE: The activity of the enzymes that metabolize tobacco smoke may affect the susceptibility to chronic obstructive pulmonary disease (COPD). Cytochrome P450 (CYP) 3A5 is expressed selectively over CYP3A4 in human lung, but the association between the CYP3A5 polymorphisms and the airway injury is unknown. METHODS: Two hundred and six male Saskatchewan grain workers participated in this longitudinal study, and their lung function values of forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC), respiratory symptoms, smoking status, and the occupational history were analyzed. RESULTS: A significant interactive effect was observed between the CYP3A5 genotype and current smoking status on FEV1, and the annual decline rates of FEV1 and FVC in current smokers were greater among CYP3A5*1/*3 carriers than CYP3A5*3/*3 carriers (-48.7+/-16.4 vs. -31.5+/-4.7 ml/years, P=0.02; -27.4+/-18.9 vs. -5.8+/-6.5 ml/years, P=0.04). The incidences of chronic cough and COPD were also higher in current smokers with CYP3A5*1/*3 than in nonsmokers and current smokers with CYP3A5*3/*3. The adjusted odds ratios for chronic cough and COPD current smokers with CYP3A5*1/*3 versus nonsmokers with the CYP3A5*3/*3 genotype were 11.4 (P=0.009) and 4.3 (P=0.13), respectively. CONCLUSION: The results suggest that CYP3A5*1 may be a novel genetic risk factor for airway injury in smokers, and that CYP3A5 may play a role in airway injury owing to the bioactivation of chemicals in tobacco smoke.     

Volcanic ash: toxicity to isolated lung cells

Samples of volcanic ash from Mount St. Helens were collected from Spokane, Washington, after the major eruption of May 18, 1980. The toxicity of ash to the lung was estimated by monitoring the effects of in vitro and in vivo exposure on various physiological parameters of isolated lung cells. Volcanic ash had little effect on O2 consumption of rabbit type II pneumocytes, O2 consumption or superoxide release of resting rat alveolar macrophages, or membrane integrity of rat alveolar macrophages. Ash also caused no significant lipid peroxidation in rat lung microsomes. However, volcanic ash did inhibit superoxide anion release from zymosan-stimulated rat alveolar macrophages. Since superoxide is an antibacterial substance, this result suggests that exposure to volcanic ash may adversely affect the ability of alveolar macrophages to protect the lung from infection.     

Respiratory effects of non-tobacco cigarettes.

Data from the Tucson epidemiological study of airways obstructive disease on smoking of non-tobacco cigarettes such as marijuana were analysed to determine the effect of such smoking on respiratory symptoms and pulmonary function. Among adults aged under 40, 14% had smoked non-tobacco cigarettes at some time and 9% were current users. The prevalence of respiratory symptoms was increased in smokers of non-tobacco cigarettes. After tobacco smoking had been controlled for men who smoked non-tobacco cigarettes showed significant decreases in expiratory flow rates at low lung volumes and in the ratio of the forced expiratory volume in one second to the vital capacity. This effect on pulmonary function in male non-tobacco cigarette smokers was greater than the effect of tobacco cigarette smoking. These data suggest that non-tobacco cigarette smoking may be an important risk factor in young adults with respiratory symptoms or evidence of airways obstruction.