Related Experiment Video

Updated: Apr 27, 2026

Methodology for Sputum Induction and Laboratory Processing
13:28

Methodology for Sputum Induction and Laboratory Processing

Published on: December 17, 2017

29.4K

Low sputum MMP-9/TIMP ratio is associated with airway narrowing in smokers with asthma

Rekha Chaudhuri1, Charles McSharry2, Jeffrey Brady3

  • 1Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK rekhachaudhuri@yahoo.com.

The European Respiratory Journal
|July 5, 2014
PubMed

Insights

Asthmatic smokers show lower matrix metalloproteinase (MMP)-9 to tissue inhibitors of metalloproteinases (TIMPs) ratios. This imbalance is linked to reduced lung function and airway remodeling in asthma patients who smoke.

Area of Science:

  • Pulmonary Medicine
  • Biochemistry
  • Respiratory Physiology

Background:

  • Asthma patients who smoke experience worse symptom control and faster lung function decline.
  • A decreased ratio of matrix metalloproteinase (MMP)-9 to tissue inhibitors of metalloproteinases (TIMPs) is linked to airway remodeling in non-smoking asthma patients.

Purpose of the Study:

  • To investigate if sputum MMP-9 activity/TIMP ratios are reduced in smokers with asthma compared to never-smokers.
  • To determine if these ratios correlate with reduced lung function and altered airway dimensions measured by CT scan.

Main Methods:

  • Measured lung function, CT-based airway dimensions, and sputum MMP-9 and TIMP levels in 81 asthmatics and 43 healthy controls.
  • Quantified respiratory epithelial MMP9 and TIMP mRNA in 31 severe asthmatics and 32 healthy controls.

Main Results:

  • Sputum MMP-9/TIMP-1 and MMP-9/TIMP-2 ratios were lower in asthmatic smokers versus never-smokers.
  • Nasal epithelial MMP9/TIMP1 and MMP9/TIMP2 expression ratios were also reduced in asthmatic smokers.
  • Low sputum ratios correlated with reduced FEV1, FEV1/FVC ratio, and airway lumen area.

Conclusions:

  • Reduced sputum MMP-9 activity/TIMP ratios in asthmatic smokers are associated with airflow obstruction and airway structural changes.
  • An imbalance of MMP-9 and TIMPs may contribute to airway remodeling in smokers with asthma.

More Related Videos

Automated Measurement of Pulmonary Emphysema and Small Airway Remodeling in Cigarette Smoke-exposed Mice10:37

Automated Measurement of Pulmonary Emphysema and Small Airway Remodeling in Cigarette Smoke-exposed Mice

Published on: January 16, 2015

12.8K
Murine Model of Allergen Induced Asthma08:05

Murine Model of Allergen Induced Asthma

Published on: May 14, 2012

40.2K

Related Concept Videos

Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features01:24

Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features

Chronic bronchitis is a key phenotype of chronic obstructive pulmonary disease (COPD), characterized by airway-centered inflammation and mucus overproduction. It develops from long-term exposure to harmful particles or gases, most commonly cigarette smoke, which triggers a persistent inflammatory response.Cellular and Structural ChangesInflammation initially affects the large bronchi and later the smaller airways, with infiltration by immune cells, including neutrophils, macrophages, and...
32
Asthma III: Clinical Manifestations01:13

Asthma III: Clinical Manifestations

Asthma presents with a characteristic pattern of episodic respiratory symptoms that reflect underlying airway inflammation, bronchoconstriction, and mucus hypersecretion. Although severity varies among individuals, certain clinical manifestations are considered hallmarks of the disorder and often guide diagnosis and assessment.Respiratory SymptomsA persistent cough is one of the most common early features of asthma. It is frequently dry and tends to worsen at night or in the early morning,...
38
Asthma I: Introduction01:28

Asthma I: Introduction

Asthma is a chronic inflammatory disorder of the airways characterized by variable airflow obstruction and heightened bronchial responsiveness to a wide range of triggers. The underlying inflammation leads to airway swelling, mucus hypersecretion, and smooth muscle constriction, all of which narrow the airway lumen and impede airflow. Clinically, asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, symptoms that typically vary in intensity and...
88
Chronic Obstructive Pulmonary Disease II: Emphysema01:23

Chronic Obstructive Pulmonary Disease II: Emphysema

Emphysema, a major phenotype of chronic obstructive pulmonary disease (COPD), is characterized by irreversible destruction of alveolar walls and permanent enlargement of distal airspaces. Unlike chronic bronchitis, which primarily affects the airways, emphysema predominantly involves the lung parenchyma, where structural damage leads to airflow limitation.PathophysiologyIt most commonly results from prolonged exposure to cigarette smoke and other toxic gases, particularly cigarette smoke.
26
Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies01:27

Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies

Assessing and diagnosing Chronic Obstructive Pulmonary Disease (COPD) involves a detailed approach that includes a comprehensive review of medical history, physical examination, and a variety of diagnostic tests. This thorough evaluation is essential to ensure an accurate diagnosis and guide effective management strategies.
Medical History
3.4K
Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture01:26

Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture

Sputum studies are a critical part of diagnosing and treating numerous respiratory conditions. These studies involve obtaining sputum samples for analysis to identify pathogenic organisms and assess the presence of abnormal cells indicative of malignant conditions. This lesson will delve into three fundamental sputum studies: Gram Stain, Cytology, and Acid-fast Smear and Culture.
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
1.3K