Related Experiment Video
Updated: Mar 7, 2026
A Reversible, Non-invasive Method for Airway Resistance Measurements and Bronchoalveolar Lavage Fluid Sampling in Mice
Published on: April 13, 2010
Altered miR-155 Expression in Allergic Asthmatic Airways
C Malmhäll1, K Johansson1, C Winkler2
1Krefting Research Centre, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Abstract:
We and others have previously identified microRNAs (miRNAs) with pathological roles in animal models of asthma, where miR-146a and miR-155 have been described to play important roles in inflammatory responses. To date, few studies have investigated miRNA expression in human asthmatics. In the current study, significantly lower levels of miR-155 were detected in cell-free sputum from allergic asthmatics compared to healthy controls. Induced sputum isolated from allergic asthmatics in and out of pollen season revealed that miR-155 expression, but not miR-146a, is reduced in lymphocytes in season compared to post-season. In contrast, miR-155 was found to increase, whereas miR-146a decreased in PBMCs and cell-free PBMC culture media upon T cell receptor stimulation via αCD3/CD28 in both allergic asthmatics and healthy controls. Our findings suggest that miR-155 is differentially expressed ex vivo in airways of allergic asthmatics compared to healthy controls, which may have implications in the local immune response in allergic asthma.
Insights
MicroRNA-155 (miR-155) levels are lower in the airways of allergic asthma patients. This finding suggests miR-155 may play a role in the local immune response of allergic asthma.
Area of Science:
- Immunology
- Molecular Biology
- Respiratory Medicine
Background:
- MicroRNAs (miRNAs) are implicated in asthma pathogenesis, with miR-146a and miR-155 known to influence inflammatory responses in animal models.
- Limited research exists on miRNA expression profiles in human asthma patients.
Purpose of the Study:
- To investigate the expression levels of miR-155 and miR-146a in allergic asthmatics compared to healthy individuals.
- To explore the dynamic changes in miRNA expression in relation to allergic asthma and seasonal variations.
Main Methods:
- Quantitative analysis of miR-155 and miR-146a in cell-free sputum and isolated lymphocytes from allergic asthmatics and healthy controls.
- Assessment of miRNA expression in peripheral blood mononuclear cells (PBMCs) and their culture media following T cell receptor stimulation.
Main Results:
- Significantly lower levels of miR-155 were observed in cell-free sputum of allergic asthmatics versus controls.
- miR-155 expression decreased in lymphocytes during pollen season in asthmatics, unlike miR-146a.
- In vitro stimulation of PBMCs showed miR-155 increased while miR-146a decreased in both asthmatics and controls.
Conclusions:
- miR-155 exhibits differential expression ex vivo in the airways of allergic asthmatics.
- These findings suggest a potential role for miR-155 in the local immune response mechanisms underlying allergic asthma.
Related Concept Videos
01:20Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
01:26Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
01:25Antiasthma Drugs: Mast Cell Stabilizers and Anti-IgE Drugs
Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without...
01:29Asthma-I: Introduction
01:19Antiasthma Drugs: Leukotriene Modifiers
Leukotriene modifiers work through two distinct mechanisms: