Positional cloning and pathway analysis of the asthma susceptibility gene, NPSR1 (original) (raw)
Related papers
New Insights into Asthma Pathogenesis
Allergy & Clinical Immunology International - Journal of the World Allergy Organization, 2004
Although Th-2-mediated inflammation is a key therapeutic target in asthma, its relationship to altered structure and functions of the airways is largely unknown. In addition to inflammation, asthma is a disorder involving the airway epithelium that is more vulnerable to environmental injury and responds to this by impaired healing. This establishes a chronic wound scenario that is capable of sustaining chronic inflammation as well as remodeling. This response occurs as a consequence of activation of the epithelial-mesenchymal unit, involving reciprocal activities of growth factors belonging to the fibroblast growth factor, epidermal growth factor, and transforming growth factor- families. The observation that structural changes in the airways in children at or before the onset of asthma occurs irrespective of inflammation might suggest that premodeling is required before Th-2 inflammatory responses can be sustained. Once established, altered function of constitutive airway cells, including fibroblasts, smooth muscle, nerves, and the epithelium, provides an abnormal microenvironment in which to generate a separate set of signals that underpin the acute/subacute inflammation characteristic of asthma exacerbations, triggered by viruses, pollutants, and allergens.
Environmental Health Perspectives, 1995
Results of studies of the epidemiology, physiology, histopathology, and cell biology of asthma have revised our conception of the disease. Epidemiologic studies have shown asthma to be an important cause of death, suffering, and economic hardship. Physiologic studies have shown that asthma is a chronic illness characterized by persistent bronchial hyperreactivity. Histopathologic studies have shown characteristic changes: epithelial damage, deposition of collagen beneath the basement membrane, eosinophilic and lymphocytic infiltration, and hypertrophy and hyperplasia of goblet cells, submucosal glands, and airway smooth muscle. Studies of the functions of cells in the airway mucosa suggest that asthma may be fundamentally mediated by a difference in the type of lymphocyte predominating in the airway mucosa but may also involve complex interactions among resident and migratory cells. Asthma may thus result from sensitization of a subpopulation of CD4+ lymphocytes, the Th2 subtype, in the airways. These lymphocytes produce a family of cytokines that favor IgE production and the growth and activation of mast cells and eosinophils, arming the airways with the mechanisms of response to subsequent reexposure to the allergen. This conceptual model has stimulated research along lines that will almost certainly lead to powerful new treatments, and it has already put current therapies in a new light, clarifying the role of antiinflammatory agents, especially of inhaled corticosteroids. This conceptual model has some limitations: it ignores new evidence on the role of the mast cell in producing cytokines and depends on results of studies of the effects of inhalation of allergen, although most asthma exacerbations are provoked by viral respiratory infection. Preliminary studies suggest that viral infection and allergen inhalation may involve the activation of different pathways, with viral infection activating production of cytokines by airway epithelial cells. Similar study of the mechanisms activated by inhalation of air toxics may provide important clues as to how they might induce or exacerbate asthma.
New insights into the pathogenesis of asthma
Journal of Clinical Investigation, 2003
Asthma is a disease whose ability to cause episodic symptomatology has been appreciated since antiquity. Although the fine points of the definition can be debated, it is reasonable to think of asthma as a pulmonary disorder characterized by the generalized reversible obstruction of airflow and to define reversibility as a greater than 12% increase in the patient's forced expiratory volume in 1 second (FEV 1 ) that occurs either spontaneously or with therapy. Airway hyperresponsiveness, an exaggerated bronchospastic response to nonspecific agents such as methacholine and histamine or specific antigens, is the physiologic cornerstone of this disorder. A diagnosis of asthma is established based on a history of recurrent wheeze, cough, or shortness of breath, reversible airway obstruction demonstrated by pulmonary-function testing, and, in cases where questions exist, a methacholine challenge demonstrating airway hyperresponsiveness. It has long been assumed that patients with asthma experience intermittent attacks and have relatively normal lung function during intervening periods. More recent studies have demonstrated that asthma can cause progressive lung impairment and, in some patients, eventuate in partially reversible or irreversible airway obstruction.
The American Journal of Pathology, 2011
Experimental nonhuman primate models of asthma exhibit multiple features that are characteristic of an eosinophilic/T helper 2 (Th2)-high asthma subtype, characterized by the increased expression of Th2 cytokines and responsive genes, in humans. Here, we determine the molecular pathways that are present in a house dust mite-induced rhesus asthma model by analyzing the genomewide lung gene expression profile of the rhesus model and comparing it with that of human Th2-high asthma. We find that a prespecified human Th2 inflammation gene set from human Th2-high asthma is also present in rhesus asthma and that the expression of the genes comprising this gene set is positively correlated in human and rhesus asthma. In addition, as in human Th2-high asthma, the Th2 gene set correlates with physiologic markers of allergic inflammation and disease in rhesus asthma. Comparison of lung gene expression profiles from human Th2-high asthma, the rhesus asthma model, and a common mouse asthma model indicates that genes associated with Th2 inflammation are shared by all three species. However, some pathophysiologic aspects of human asthma (ie, subepithelial fibrosis, angiogenesis, neural biology, and immune host defense biology) are better represented in the gene expression profile of the rhesus model than in the mouse model. Further study of the rhesus asthma model may yield novel insights into the pathogenesis of human Th2-high asthma.
Various Cellular and Molecular Axis Involved in the Pathogenesis of Asthma
Targeting Cellular Signalling Pathways in Lung Diseases, 2021
Asthma is a chronic inflammatory disease described by impaired lung function, airway hyperresponsiveness, episodic wheezing, and dyspnea. Asthma prevalence has risen drastically, and it is estimated that more than 339 million individuals worldwide had asthma with marked heterogeneity in pathophysiology
Medicine, 2008
asthma is a syndrome of variable airflow obstruction. it is character ized pathologically by bronchial inflammation with prominent eosinophil infiltration and remodelling changes, physiologically by bronchial hyper responsiveness, and clinically by cough, chest tightness and wheeze. cytokines secreted by cD4+ th2 type t cells play a major role in co ordinating asthmatic bronchial inflammation and remodelling, while other effector cells, particularly eosinophils and myofibroblasts, play an intermediary role in airways damage and remodelling. although the patho logical changes in the airways in association with asthma are now well described, there is a gap in our understanding of precisely how these changes cause clinical symptoms. a key aetiological factor for asthma is exposure to inhaled allergens, including occupational allergens, which are probably a major drive to t cell activation in asthma. Genetic factors governing the production of t cell cytokines and their actions on target cells, as well as variability in the structure and development of the mesenchymal elements of the bronchial mucosa, influence the risk of developing asthma. many other environmental agents exacerbate asthma but the evidence that they cause disease is much less clear.
New Insights Into the Understanding of Asthma
Chest, 1997
The prevalence of asthma is increasing, despite better understanding of its pathogenesis and improved treatments. During the past 10 years, the perception of asthma has shifted from a disease primarily characterized by altered smooth muscle function to one mainly characterized by chronic inflammation. This article reviews the evidence supporting the relationship of inflammation in both the upper and lower airways, focusing on intermittent seasonal disease as well as on the more chronic and severe forms of asthma, including that associated with aspirin intolerance. It also presents evidence to support a pivotal role for the epithelial cell, together with the mast cell and the eosinophil, in initiating and maintaining inflammation in the upper and lower airways.
Immunity and asthma: friend or foe?
Oriental Pharmacy and Experimental Medicine, 2008
Immunity is responsible for the defense mechanism of the body but in case of autoimmune diseases, its role gets diverted. Like so many other diseases, asthma is also considered as one of the most common autoimmune diseases to be occurring in community. Asthma is defined as a chronic inflammatory airway disease that is characterized by airway hyper reactivity and mucus hypersecretion that result in intermittent airway obstruction. The incidence of allergic asthma has almost doubled in the past two decades. Although, precise causative mechanism of asthma is unknown, but several mechanisms have been proposed that is immunological, pharmacological and genetic mechanisms, and airway and neurogenic inflammation. The inflammatory process observed in the asthmatic patients is the final result of a complex network of interactions between various immunological cell lineages, its mediators and secreted substances. Thus, among the mechanisms proposed, the immunological one plays a key role. Through this article, we have tried to provide some insight into immunological mechanisms in pathogenesis of asthma.