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)

Asthma and chronic obstructive pulmonary disease (COPD) are complex conditions with imprecise definitions that make definitive morphological comparisons difficult. Asthma may be divided into extrinsic (allergic), intrinsic (late onset), and occupational forms. The airways in fatal asthma are occluded by markedly tenacious plugs of exudate and mucus; there is fragility of airway surface epithelium, thickening of the reticular basement membrane, and bronchial vessel dilatation, congestion, and edema. There is enlargement of bronchial smooth muscle and also of submucosal gland mass, particularly in medium-sized bronchi. There is increased inflammatory infiltrate comprising activated lymphocytes and eosinophils with release of granular content in the latter; the allergic inflammation is associated with gene expression for interleukins IL-4 and IL-5 (ie, TH2 phenotype) and also GMCSF and TNF alpha. Many of these changes are already present in mild forms of asthma. In comparison, three conditions contribute to COPD: (1) In chronic bronchitis there is inflammation associated with mucous hypersecretion, enlargement of tracheo-bronchial submucosal glands, and a disproportionate increase of acidic mucus. The reticular basement membrane is not consistently thickened. (2) In small (peripheral) airways disease there is a macrophage bronchiolitis, mucous metaplasia and hyperplasia, increased intraluminal mucus, increased wall muscle, fibrosis, and airway stenoses. Respiratory bronchiolitis and loss of alveolar wall attachments are important lesions. (3) Emphysema involves elastolytic destruction of the alveolar wall; its overall severity, rather than type, appears to be an important determinant of chronic irreversible deterioration of airflow in COPD.
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PMID:Comparative morphology of the airways in asthma and chronic obstructive pulmonary disease. 795 95

Asthma and chronic obstructive pulmonary disease (COPD) are complex conditions with imprecise definitions, which make definitive morphological comparisons difficult. The airways in asthma are occluded by tenacious plugs of exudate and mucus, and there is fragility of airway surface epithelium, thickening of the reticular layer beneath the epithelial basal lamina (the last two not usually features of COPD), and bronchial vessel congestion and oedema. There is an increased inflammatory infiltrate comprising 'activated' lymphocytes and eosinophils with release of granular content in the latter, and enlargement of bronchial smooth muscle, particularly in medium-sized bronchi. CD4+ve lymphocytes predominate over CD8+ve cells and neutrophils are sparse. In contrast, three conditions contribute to COPD. In chronic bronchitis there is cough and mucous hypersecretion with enlargement of tracheobronchial submucosal glands and a disproportionate increase of mucous acini. CD8+ve lymphocytes predominate over CD4+ve cells and there are increased numbers of subepithelial macrophages and intra-epithelial neutrophils. Exacerbations of bronchitis are associated with a tissue eosinophilia, apparent absence of IL-5 protein but gene expression for IL-4 and IL-5 is present. In small or peripheral airways disease, there is inflammation of bronchioli and mucous metaplasia and hyperplasia, with increased intraluminal mucus, increased wall muscle, fibrosis, and airway stenoses (also referred to as chronic obstructive bronchiolitis). Respiratory bronchiolitis involving increased numbers of pigmented macrophages is a critically important early lesion. Increasingly severe peribronchiolitis includes infiltration of T lymphocytes in which the CD8+ subset again predominates. These inflammatory changes may predispose to the development of centrilobular emphysema and reduced FEV1 via the destruction of alveolar attachments. In emphysema there is abnormal, permanent enlargement of airspaces distal to the terminal bronchiolus (i.e. within the acinus) accompanied by destruction of alveolar walls and without obvious fibrosis. The severity of emphysema, rather than type, appears to be the most important determinant of chronic deterioration of airflow, and in this there may be significant loss of elastic recoil and microscopic emphysema prior to the observed macroscopic destruction of the acinus.
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PMID:Differences and similarities between chronic obstructive pulmonary disease and asthma. 1042 18

Chronic obstructive pulmonary disease (COPD) is a cytotoxic T lymphocyte (CD8)- and macrophage (CD68)-predominant chronic inflammatory disorder of the conducting airways and alveoli. This is often associated with a neutrophilia, inflammation of small airways and destruction of tissue beyond the terminal bronchiolus, i.e. emphysema. In contrast, asthma is a helper T cell (CD4; type 2)-predominant chronic inflammatory disorder of the conducting airways in which there is T lymphocyte-derived gene expression for interleukin (IL)-4 and IL-5 but not interferon gamma. There is fragility of airway surface epithelium, thickening of the reticular basement membrane, bronchial vessel congestion and (when severe) an increase in the mass of bronchial smooth muscle. This is usually (but not always) associated with tissue and peripheral blood eosinophilia rather than a neutrophilia and there is exudative plugging of the airways. These differences of inflammatory profile, remodelling and lung function are seen when smokers with COPD are compared with non-smoking mild asthmatics. However there may be important similarities and overlap, particularly in more severe asthma when neutrophils predominate and in the older and or smoking asthmatic when reversibility of airflow is less obvious. We have recently demonstrated gene expression for IL-4 and IL-5 in and around the mucus-secreting glands of airways resected from smokers without a history of asthma. Also exacerbations of bronchitis may be associated with a tissue eosinophilia. On examination of bronchial biopsies from these patients we show surprisingly strong gene expression for IL-4, IL-5 and even human eotaxin and RANTES (regulated on activation normal T cell expressed and secreted). Whilst CD4 T lymphocytes of the Th2 phenotype might be expressing these cytokines in bronchitis, CD8 T lymphocytes are also capable of secreting IL-4 and IL-5. Viruses may modulate these changes in distinct lymphocyte functional phenotypes. The relevance and importance of CD4/CD8 T lymphocyte ratio to the development of COPD is discussed.
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PMID:Lymphocytes, chronic bronchitis and chronic obstructive pulmonary disease. 1119 94

Exposure to airborne endotoxin in infancy may protect against asthma by promoting enhanced T(H)1 response and tolerance to allergens. On the other hand, later in life, it adversely affects patients with asthma. Endotoxin binding to receptors on macrophages and other cells generates IL-12, which inhibits IgE responses. It also generates cytokines like IL-1, TNF-alpha, and IL-8, which cause inflammation. These signal transduction pathways resemble those leading to the generation of cytokines, such as IL-4, IL-13, and IL-5, which are responsible for the inflammation of IgE-mediated allergic disease. The main difference seems to be that endotoxin recruits neutrophils, but IgE recruits eosinophils, and the details of the tissue injury from these granulocytes differ. Sources of airborne endotoxin include many agricultural dusts, aerosols from contaminated water in many industrial plants, contaminated heating and air-conditioning systems, mist-generating humidifiers, and damp or water-damaged homes. Acute inhalation of high concentrations of endotoxin can cause fever, cough, and dyspnea. Chronic inhalation of lesser amounts causes chronic bronchitis and emphysema and is associated with airway hyperresponsiveness. Airborne endotoxin adversely affects patients with asthma in 3 ways: (1) by increasing the severity of the airway inflammation; (2) by increasing the susceptibility to rhinovirus-induced colds; and (3) by causing chronic bronchitis and emphysema with development of irreversible airway obstruction after chronic exposure of adults. The most effective management is mitigating exposure. The potential of drug treatments requires further clinical investigation.
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PMID:Endotoxin-stimulated innate immunity: A contributing factor for asthma. 1149 29

The TSK/TSK mutation is embryonic lethal; embryos have been reported to die at 7-8 days of gestational age. Crossing TSK/+, IL-4+/- mice revealed that disrupting one or both IL-4 alleles allowed survival of 29 and 47%, respectively, of TSK/TSK mice. These mice failed to develop cutaneous hyperplasia but did exhibit the emphysema that is found in TSK/+ mice. We showed that IL-4 stimulation of fibroblasts increased the level of transforming growth factor-beta (TGF-beta) mRNA and that lungs of TSK/+, IL-4-/- mice had substantially less TGF-beta mRNA than lungs of TSK/+, IL-4+/+ mice. Thus IL-4 seems to regulate the expression of TGF-beta in fibroblasts, providing an explanation for the absence of cutaneous hyperplasia in TSK/+, IL-4Ralpha-/- and TSK/+, TGF-beta+/- mice.
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PMID:Disrupting the IL-4 gene rescues mice homozygous for the tight-skin mutation from embryonic death and diminishes TGF-beta production by fibroblasts. 1189 15

Immunostimulatory CpG motifs can preferentially induce Th1 immune responses and have been applied to treat Th2-dominant disease. In this study, we investigated whether a plasmid with the addition of 20 copies of an immunostimulatory CpG motif (pB-CpG20) might prevent the development of scleroderma-like syndrome in tight-skin (Tsk/+) mice. Administration of pB-CpG20 to Tsk/+mice every 3 weeks starting at the age of 1 week reduced skin thickness and collagen content compared to that of pB or saline. The reduction was long lasting even after halting the treatment. Furthermore, this treatment partially reduced the production of anti-nuclear antibodies although it did not decrease the incidence of lung emphysema. pB-CpG20 increased the number of spleen cells secreting IFN-gamma and reduced that of the cells secreting IL-4 in vivo and in vitro compared to saline. These results suggest that repeated administration of a CpG-enriched plasmid can ameliorate scleroderma-like syndrome by biasing Th1 immunity in young Tsk/+mice.
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PMID:Therapeutic effect of CpG-enriched plasmid administration on the tight-skin mouse model of scleroderma. 1584 40

Tight-skin (Tsk/+) mice develop a disease similar to human scleroderma, characterized by the spontaneous appearance of cutaneous hyperplasia, anti-nuclear antibodies, and emphysema. T helper (Th) 2 cells secreting interleukin (IL)-4 are known to play a critical role in the etiopathogenesis of this disease. Th2-mediated responses can be blocked by treatment with synthetic oligodeoxynucleotides (ODN) containing immunomodulatory CpG motifs. Thus, we examined whether CpG ODN might be of therapeutic benefit in Tsk/+ mice. Administering CpG ODN to Tsk/+ mice every 3 wk starting at 1 wk of age abrogated skin fibrosis. This reduction in skin thickness persisted even after the cessation of therapy, and was accompanied by increased serum levels of IL-12 and an increased ratio of T cells available to secrete interferon-gamma rather than IL-4. CpG ODN therapy also reduced autoantibody production, but did not inhibit the incidence of lung emphysema. Delaying the initiation of CpG ODN treatment until 6 wk of age failed to prevent skin disease. These results indicate that by preferentially promoting the development of a Th1-biased immune milieu in young Tsk/+ mice, CpG ODN can ameliorate Th2-driven scleroderma-like syndrome.
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PMID:CpG oligodeoxynucleotides prevent the development of scleroderma-like syndrome in tight-skin mice by stimulating a Th1 immune response. 1595 88

The rat has been extensively used to model asthma and somewhat less extensively to model chronic obstructive pulmonary disease (COPD). The features of asthma that have been successfully modeled include allergen-induced airway constriction, eosinophilic inflammation and allergen-induced airway hyperresponsiveness. T-cell involvement has been directly demonstrated using adoptive transfer techniques. Both CD4+ and CD8+ T cells are activated in response to allergen challenge in the sensitized rat and express Thelper2 cytokines (IL-4, IL-5 and IL-13). Repeated allergen exposure causes airway remodeling. Dry gas hyperpnea challenge also evokes increases in lung resistance, allowing exercise-induced asthma to be modeled. COPD is modeled using elastase-induced parenchymal injury to mimic emphysema. Cigarette smoke-induced airspace enlargement occurs but requires months of cigarette exposure. Inflammation and fibrosis of peripheral airways is an important aspect of COPD that is less well modeled. Novel approaches to the treatment of COPD have been reported including treatments aimed at parenchymal regeneration.
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PMID:Rat models of asthma and chronic obstructive lung disease. 1633 18

Airway epithelial inflammation associated with emphysema, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and asthma is regulated in part by alveolar type II cell chemokine signaling. Data suggest that resident lung cells use CCR3, CCR5 and CCR2 chemokine receptor/ligand systems to regulate the profile of leukocytes recruited in disease-associated inflammatory conditions. Thus studies were designed to test whether alveolar type II cells possess a Th1-activated CCR5-ligand system that modulates the Th2-activated CCR3/eotaxin-2 (CCL24), eotaxin-3 (CCL26) chemokine systems. The A549 alveolar type II epithelial-like cell culture model was used to demonstrate that alveolar type II cells constitutively express CCR5 which may be upregulated by MIP-1alpha (CCL3) whose expression was induced by the Th1 cytokines IL-1beta and IFN-gamma. Selective down-regulation of CCL26, but not CCL24, was observed in CCL3 and IL-4/CCL3 stimulated cells. Down-regulation was reversed by anti-CCR5 neutralizing antibody treatment. Thus, one mechanism through which Th1-activated CCCR5/ligand pathways modulate Th2-activated CCR3/ligand pathways is the differential down-regulation of CCL26 expression. Results suggest that the CCR3 and CCR5 receptor/ligand signaling pathways may be important targets for development of novel mechanism-based adjunctive therapies designed to abrogate the chronic inflammation associated with airway diseases.
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PMID:Modulation of eotaxin-3 (CCL26) in alveolar type II epithelial cells. 1735 Feb 79

Recently, patients with tobacco smoke induced emphysema have been shown to exhibit classical signs of T cell mediated autoimmunity characterized by autoantibody production and Th1 type responses. As the recently described Th17 type subset has been found to play a role in the pathogenesis of a number of autoimmune diseases previously considered to be Th1 driven, we sought to examine whether a Th17 type response was associated with airspace enlargement in a murine model of emphysema. Six to eight months exposure of mice to inhalation of mainstream cigarette smoke led to progressive airspace enlargement as defined by morphometric analysis. Flow cytometric analysis of the bronchoalveolar lavage (BAL) from these mice demonstrated a significant increase in the overall number of both CD4+ and CD8+ T cells present. These cells were subsequently examined for skewing towards a Th1, Th2 or Th17 phenotype by intracellular cytokine analysis. Distinct populations of BAL CD4+ T cells were found to express IFN-gamma or IL-17 demonstrating the presence of both a Th1 and Th17 type response. No expression of the Th2 associated cytokine IL-4 was detected. Further analysis of this Th17 subset demonstrated that the majority of cells with this effector phenotype express the chemokine receptor CCR6. Together these data identify a novel T cell subset associated with pulmonary inflammation as a result of cigarette smoke exposure. Given the reported roles of CCR6 and IL-17 in promoting pulmonary inflammation, this subset may play an important role in the pathogenesis of cigarette smoke induced autoimmunity.
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PMID:Airway infiltration of CD4+ CCR6+ Th17 type cells associated with chronic cigarette smoke induced airspace enlargement. 1870 44


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