Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034067 (emphysema)
 11,506 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The de novo pathway of ceramide synthesis has been implicated in the pathogenesis of excessive lung apoptosis and murine emphysema. Intracellular and paracellular-generated ceramides may trigger apoptosis and propagate the death signals to neighboring cells, respectively. In this study we compared the sphingolipid signaling pathways triggered by the paracellular- versus intracellular-generated ceramides as they induce lung endothelial cell apoptosis, a process important in emphysema development. Intermediate-chain length (C(8:0)) extracellular ceramides, used as a surrogate of paracellular ceramides, triggered caspase-3 activation in primary mouse lung endothelial cells, similar to TNF-alpha-generated endogenous ceramides. Inhibitory siRNA against serine palmitoyl transferase subunit 1 but not acid sphingomyelinase inhibited both C(8:0) ceramide- and TNF-alpha (plus cycloheximide)-induced apoptosis, consistent with the requirement for activation of the de novo pathway of sphingolipid synthesis. Tandem mass spectrometry analysis detected increases in both relative and absolute levels of C(16:0) ceramide in response to C(8:0) and TNF-alpha treatments. These results implicate the de novo pathway of ceramide synthesis in the apoptotic effects of both paracellular ceramides and TNF-alpha-stimulated intracellular ceramides in primary lung endothelial cells. The serine palmitoyl synthase-regulated ceramides synthesis may contribute to the amplification of pulmonary vascular injury induced by excessive ceramides.
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PMID:Apoptotic sphingolipid signaling by ceramides in lung endothelial cells. 1819 2

Tumor necrosis factor (TNF)-alpha is a key pro-inflammatory cytokine, thought to be important in the pathogenesis of pulmonary emphysema. TNF-alpha overexpression in the lung leads to the phenotypic features of pulmonary emphysema, pulmonary hypertension, and right ventricular hypertrophy in mice bred in Denver, 5240 feet/1600 m of altitude. This study hypothesized that the altitude could affect the development of pulmonary emphysema as well as pulmonary hypertension. To investigate the effect of the altitude, TNF-alpha transgenic mice were bred at sea level, Fukuoka, Japan. The pulmonary physiology and histology demonstrated similar development of pulmonary emphysema, compared to the mice bred in Denver. With respect to pulmonary hypertension, right ventricular hypertrophy was attenuated. Interestingly, mortality rate was significant lower in the mice bred at sea level. In contrast with the results in Denver, a significant decrease of vascular endothelial growth factor (VEGF) and its receptors expression was not found. From these data, we consider that the altitude affects development of pulmonary hypertension through the expression of VEGF and its receptors. In contrast, the effect of altitude was not clear regarding the development of pulmonary emphysema.
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PMID:Attenuation of pulmonary hypertension, but not emphysematous change, by breeding emphysema model mice at sea level. 1820 85

Cigarette smoke is the most important cause for the development of chronic obstructive pulmonary disease (COPD). Since only a minority of smokers and some nonsmokers develop COPD, other factors must be involved as well. NO2 is an important air pollutant associated with respiratory symptoms in humans and emphysema development in animal models. We hypothesized that combined exposure to NO2 and cigarette smoke will enhance pulmonary inflammation and emphysema development. Mice were exposed to 20 ppm NO2 for 17 h/day, to 24 puffs of cigarette smoke 2 times per day, to their combination, or to control air for 5 days/wk during 4 wk. Following the last NO2 exposure and within 24 h after the last smoke exposure the mice were sacrificed. Lungs were removed and analyzed for several inflammatory parameters and emphysema. Cigarette smoke exposure increased eosinophil numbers and levels of tumor necrosis factor (TNF)-alpha, KC, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6. NO2 exposure increased goblet cells, eosinophils, and the levels of IL-6, while it decreased the levels of IL-10. Four weeks of NO2, cigarette smoke, or their combination was not sufficient to induce significant emphysema, nor did it lead to increased numbers of lymphocytes, neutrophils, or macrophages in lung tissue. Instead, NO2 exposure attenuated the smoke-induced increases in levels of TNF-alpha, KC, and MCP-1. These dampening effects of NO2 may be due to modulating effects of NO2 on cytokine production by macrophages and epithelial cells, which have been reported earlier. The next step is to translate these findings of combined, controlled exposure in animals to the human situation.
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PMID:Nitrogen dioxide exposure attenuates cigarette smoke-induced cytokine production in mice. 1823 32

Cigarette smoking is associated with the development of inflammatory lung diseases representing major health problems world-wide. We hypothesized that the redox-regulating molecule thioredoxin-1 (TRX), which shows anti-inflammatory, antioxidative, and antiapoptotic effects, could be induced by cigarette smoke (CS) and contribute to protect against CS-induced inflammation and lung destruction. In an acute study, human TRX transgenic mice and C57BL6/J mice were exposed to mainstream CS for 3 days. In the lungs of CS-exposed mice, bronchial epithelial injury and bronchoalveolar lavage neutrophilia were observed. Oxidative stress and apoptosis were enhanced, and the expression of cytokines macrophage inflammatory protein-2 and tumor necrosis factor (TNF)-alpha was increased 15.3- and 2.4-fold, respectively. Compared with C57BL6/J mice, TRX-transgenic mice had significantly less inflammation, oxidative damage, and apoptosis, as well as decreased levels of matrix metalloprotease-12 mRNA and serum TNF-alpha. When recombinant human TRX (40 microg/body/day, 3 days) was injected i.p. into CS-exposed C57BL6/J mice, a significant effect to offer protection against CS-induced lung injury was observed through suppression of neutrophil influx. In the chronic study, TRX-transgenic mice and C57BL6/J mice were exposed to CS for 6 months. This chronic exposure caused pulmonary emphysema in C57BL6/J mice accompanying prominent infiltration of macrophages and neutrophils to lung. These pathological changes were significantly suppressed in TRX-transgenic mice. In conclusion, TRX induction ameliorated CS-induced lung inflammation and emphysema in mice. TRX-1 may therefore play a preventive or therapeutic role in lung inflammatory disorders such as chronic obstructive pulmonary disease.
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PMID:Thioredoxin-1 ameliorates cigarette smoke-induced lung inflammation and emphysema in mice. 1825 71

Idiopathic pulmonary fibrosis has been associated with emphysema in cigarette smokers as a new clinical entity: combined pulmonary fibrosis and emphysema (CPFE). In order to compare histomorphometrical, roentgenological and immunohistochemical aspects of usual interstitial pneumonia (UIP) with and without associated pulmonary emphysema, 17 patients with biopsy-proven UIP were evaluated. Morphometrical evaluation of lung parenchyma destruction was used to divide patients in two subgroups: emphysema/UIP (n=9) and UIP alone (n=8); four patients with biopsy-proven emphysema without fibrosis were also evaluated. At HRTC scan, emphysematous lesions were prevalent in the upper fields of both emphysema/UIP and emphysema groups and the distribution of fibrotic lesions was similar in emphysema/UIP compared to UIP alone. The semiquantitative histopathological fibrotic score was also similar in emphysema/UIP and UIP alone. In addition, the expression of tumor necrosis factor (TNF)-alpha, matrix metalloproteinase (MMP)-2, MMP-9, MMP-7 and membrane type 1-metalloproteinase (MT1-MMP) by fibroblasts of myofibroblastic foci was similar in emphysema/UIP and UIP alone patients. In contrast, fibroblasts in areas of parenchymal destruction of emphysema/UIP expressed MMP-2, MMP-9, MMP-7 and MT1-MMP at variable but significantly higher levels when compared to emphysema subjects, in the presence of similar levels of TIMP-1, TIMP-2 and TNF-alpha. Fibrotic and emphysematous lesions in emphysema/UIP patients appear to follow the roentgenological and histopathological patterns expected for either UIP or emphysema. Interstitial fibroblast activation is more pronounced in the areas of lung destruction in emphysema/UIP compared to those with emphysema alone, as for exaggerated tissue remodeling.
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PMID:HRCT and histopathological evaluation of fibrosis and tissue destruction in IPF associated with pulmonary emphysema. 1872 34

Interleukin-1beta (IL-1beta), a proinflammatory cytokine, is elevated in cigarette smokers. To determine whether IL-1beta plays a role in the pathogenesis of cigarette smoke-induced emphysema and small airway remodeling, IL-1 receptor knockout (IL1RKO), TNF-alpha receptor knockout (TNFRKO), or C57Bl/6 (control) mice were exposed to cigarette smoke acutely or for up to 6 months. With a single acute exposure, smoke elevated IL-1beta in C57Bl/6 mice. IL1RKO mice were protected against acute smoke-mediated increases in lavage inflammatory cells and matrix breakdown. In C57Bl/6 mice, acute smoke-mediated increases in inflammatory cells, serum IL-1beta, and serum TNF-alpha were blocked by z-VAD-fmk, a pan-caspase inhibitor, or z-WEHD-fmk, a caspase-1 (IL-1-converting enzyme, [ICE]) inhibitor. With 6 months of exposure, IL-1beta was no longer increased, but IL-18 was elevated. After 6 months of exposure, IL1RKO mice were 65% protected against emphysema, whereas TNFRKO mice were 83% protected. Both strains were completely protected against small airway remodeling. Lavage desmosine, hydroxyproline, and hyaluronan, matrix breakdown markers, were elevated in C57 but not IL1RKO mice. We conclude that IL-1beta plays a significant role in induction of murine emphysema and small airway remodeling, and is comparable to TNF-alpha in its effects. The protective effects of caspase inhibitors appear to be related to inhibition of ICE and raise the question of whether models that ameliorate emphysema with caspase inhibitors are really blocking IL-1beta (and IL-18) activation rather than blocking apoptosis.
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PMID:The role of interleukin-1beta in murine cigarette smoke-induced emphysema and small airway remodeling. 1893 27

Cigarette smoking is the most commonly encountered risk factor for chronic obstructive pulmonary disease (COPD), reflected by irreversible airflow limitation, frequently associated with airspace enlargement and pulmonary inflammation. In addition, COPD has systemic consequences, including systemic inflammation, muscle wasting, and loss of muscle oxidative phenotype. However, the role of smoking in the development of these extrapulmonary manifestations remains rather unexplored. Mice were exposed to cigarette smoke or control air for 6 months. Subsequently, emphysema was assessed by morphometry of lung tissue, and blood cytokine and chemokine levels were determined by a multiplex assay. Soleus, plantaris, gastrocnemius, and tibialis muscles were dissected and weighed. Muscle fiber typing was performed based on I, IIA, IIB, and IIX myosin heavy-chain isoform composition. Lungs of the smoke-exposed animals showed pulmonary inflammation and emphysema. Moreover, circulating levels of primarily proinflammatory proteins, especially TNF-alpha, were elevated after smoke exposure. Despite an attenuated body weight gain, only the soleus showed a tendency toward lower muscle weight after smoke exposure. Oxidative fiber type IIA proportion was significantly reduced in the soleus. Muscle oxidative enzyme activity was slightly reduced after smoke exposure, being most prominent for citrate synthase in the soleus and tibialis. In this mouse model, chronic cigarette smoke exposure resulted in systemic features that closely resemble the early signs of the extrapulmonary manifestations observed in patients with COPD.
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PMID:Extrapulmonary manifestations of chronic obstructive pulmonary disease in a mouse model of chronic cigarette smoke exposure. 1898 19

Animal models of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) provide potentially useful ways to test drug therapies, either by direct administration of the treatment of interest, or by use of genetically modified animals that mimic the actions of the drug of interest. Evaluation of the potential effects of a drug in animal models requires a long-term (generally 6-mo) smoke exposure to produce/prevent lesions because acute models do not completely predict chronic events. There are now more than 30 chronic studies in the literature which, in aggregate, show that antiproteolytic therapies, antiinflammatory therapies, and antioxidant therapies substantially or completely prevent emphysema, small airway remodeling, and pulmonary hypertension in laboratory animals. However, the few corresponding trials in humans (anti-TNF-alpha therapy, PDE4 inhibitors) have produced only minor improvements or failed to prevent disease progression. New data from our laboratory indicates that, at least for murine emphysema, the development of disease goes through different phases, with early repair and late failure to repair smoke-induced damage. These observations suggest that the potential effects of drug treatment in humans may vary depending on the stage of the disease and that treatment may be more effective in relatively early disease. An additional complicating factor is that interventions that ameliorate emphysema may or may not prevent small airway remodeling and/or pulmonary hypertension, suggesting that different therapeutic approaches may be needed for the various different anatomic lesions of COPD.
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PMID:Testing drugs in animal models of cigarette smoke-induced chronic obstructive pulmonary disease. 1974 Dec 68

The aim of this study was to determine the impact of HRCT-confirmed emphysema on biomarkers evaluating airway and systemic inflammation in COPD patients. Forty-nine consecutive male COPD outpatients with stable COPD were divided in two groups according to the presence or absence of emphysema on HRCT. Patients underwent pulmonary function tests, plus assessment of exercise capacity, body composition and quality of life. Biomarkers were measured in serum (CRP, interleukin-6, TNF-alpha, leptin, adiponectin, osteocalcin, insulin growth factor-1, and systemic oxidative stress), in plasma (fibrinogen and VEGF) and in whole blood (B-type natriuretic peptide). TNF-alpha, 8-isoprostane and pH were additionally measured in exhaled breath condensate. Patients with emphysema had more severe lung function impairment, lower body-mass index and fat-free mass index, and poorer quality of life. Additionally, they presented increased systemic oxidative stress and plasma fibrinogen and lower BNP compared to patients without emphysema. After proper adjustment for disease severity, all differences remained with the exceptions of body-mass index, fat-free mass index and BNP. COPD patients with HRCT-confirmed emphysema present increased systemic oxidative stress and fibrinogen, suggesting that they may be more prone to the systemic consequences of COPD compared to patients without emphysema.
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PMID:Systemic and airway inflammation and the presence of emphysema in patients with COPD. 1985 37

Macrophages are key inflammatory cells in chronic obstructive pulmonary disease (COPD). The pathophysiology of cigarette smoke-induced lung emphysema is complex but there is a clear role for reactive oxygen species (ROS, such as peroxynitrite), tumor necrosis factor (TNF-alpha) and interleukin (IL)-8. We investigated whether TNF-alpha or cigarette smoke medium (CSM) alone or in combination induces the production of IL-8 by human macrophages or monocyte lymphoma U937. CSM and TNF-alpha induce a dose- and time-dependent increase in IL-8 production. Interestingly, when sub-threshold concentrations of CSM and TNF-alpha were co-incubated, a 1500% increase in IL-8 production was observed compared to either of the compounds alone. Similar results were obtained with TNF-alpha and the peroxynitrite donor SIN-1. Moreover, the overproduction of IL-8 was associated with an enhanced increase in the translocation of NF-kappaB and an enhanced decrease in glutathione levels. Preincubation of the cells with antioxidants, such as N-acetyl-L-cysteine (NAC), prevented the overproduction of IL-8 and activation of NF-kappaB. In conclusion, CSM exposure of macrophages up-regulates the expression and the production of IL-8 via reactive oxygen species and NF-kappaB activation. Moreover, CSM dramatically enhances the production of IL-8 in combination with TNF-alpha. Based upon the strong synergistic action, a combination therapy directed against ROS and TNF-alpha could be a new approach to stop the progression in lung damage during emphysema.
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PMID:IL-8 production by macrophages is synergistically enhanced when cigarette smoke is combined with TNF-alpha. 1987


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