Related Experiment Video

Updated: Jun 7, 2026

Lung microRNA Profiling Across the Estrous Cycle in Ozone-exposed Mice
07:07

Lung microRNA Profiling Across the Estrous Cycle in Ozone-exposed Mice

Published on: January 7, 2019

MicroRNA expression in induced sputum of smokers and patients with chronic obstructive pulmonary disease

Geert R Van Pottelberge1, Pieter Mestdagh, Ken R Bracke

  • 1Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium.

American Journal of Respiratory and Critical Care Medicine
|November 2, 2010
PubMed
Abstract

Insights

MicroRNAs (miRNAs) like let-7c are reduced in chronic obstructive pulmonary disease (COPD) patients, correlating with increased TNFR-II. This finding offers insights into COPD pathogenesis and potential therapeutic targets.

Area of Science:

  • Pulmonary Medicine
  • Molecular Biology
  • Genetics

Background:

  • Chronic obstructive pulmonary disease (COPD) involves progressive airway inflammation and disrupted pulmonary cell homeostasis.
  • MicroRNAs (miRNAs) are key regulators of gene expression, influencing cellular processes relevant to COPD.

Purpose of the Study:

  • To identify specific miRNA expression profiles in induced sputum of COPD patients.
  • To compare miRNA expression between COPD patients and individuals without airflow limitation.

Main Methods:

  • Quantitative polymerase chain reaction (qPCR) was used to evaluate the expression of 627 miRNAs in sputum supernatant.
  • Differential expression was validated in an independent cohort, followed by in silico target gene analysis and ELISA for protein validation.

Main Results:

  • Thirty-four miRNAs showed differential expression between smokers and non-smokers without airflow limitation.
  • Eight miRNAs, including let-7c and miR-125b, were significantly downregulated in COPD patients compared to healthy individuals.
  • Reduced let-7c levels in severe COPD sputum correlated with increased tumor necrosis factor receptor type II (TNFR-II) protein.

Conclusions:

  • let-7c is significantly decreased in the sputum of current smokers with COPD.
  • The reduced let-7c expression is associated with elevated TNFR-II levels, suggesting a role in COPD pathogenesis.

More Related Videos

Measuring Carbon Content in Airway Macrophages Exposed to Carbon-Containing Particulate Matters05:18

Measuring Carbon Content in Airway Macrophages Exposed to Carbon-Containing Particulate Matters

Published on: July 12, 2024

Isolation of Mouse Respiratory Epithelial Cells and Exposure to Experimental Cigarette Smoke at Air Liquid Interface10:47

Isolation of Mouse Respiratory Epithelial Cells and Exposure to Experimental Cigarette Smoke at Air Liquid Interface

Published on: February 21, 2011

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...
Microbiota of the Respiratory Tract01:29

Microbiota of the Respiratory Tract

The human respiratory tract, comprising the upper and lower segments, serves as a critical interface with the external environment. The upper respiratory tract (URT)—including the nostrils, sinuses, pharynx, and oropharynx—is heavily colonized by microbes, while the lower respiratory tract (LRT), composed of the larynx, trachea, bronchi, and lungs, was long thought to be sterile. However, recent molecular studies have revealed that the lungs are not devoid of microbes but act more like...
Chronic Obstructive Pulmonary Disease-II: Pathophysiology01:20

Chronic Obstructive Pulmonary Disease-II: Pathophysiology

Chronic Obstructive Pulmonary Disease (COPD) pathophysiology is intricate and multifaceted, involving a complex interplay of physiological processes. Understanding these mechanisms is crucial for effectively managing and treating COPD. Here is an in-depth look at the critical elements in the pathophysiology of COPD:
Chronic Inflammation
Chronic Obstructive Pulmonary Disease01:24

Chronic Obstructive Pulmonary Disease

COPD is defined as a heterogeneous lung condition marked by persistent respiratory symptoms such as dyspnea, cough, and sputum production, caused by abnormalities in the airways that cause airflow obstruction.
Smoking is a primary risk factor for COPD, with over 80% of patients having a history of it. Patients typically experience progressive dyspnea or labored breathing, frequent coughing, and recurrent pulmonary infections. Many eventually succumb to respiratory failure, characterized by...
Chronic Obstructive Pulmonary Disease I: Introduction01:23

Chronic Obstructive Pulmonary Disease I: Introduction

Chronic obstructive pulmonary disease is a common, preventable, and treatable respiratory disorder characterized by persistent symptoms and progressive airflow limitation. This limitation results from a combination of small-airway disease (obstructive bronchiolitis) and parenchymal destruction (emphysema), both driven by chronic inflammation from exposure to harmful particles or gases.The disease includes two main pathological entities: emphysema, marked by destruction of alveolar walls and...
MicroRNAs01:22

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns (non-coding regions of a gene) or intergenic regions (stretches of DNA present between genes). Several processing steps are required to form biologically active, mature miRNA. The initial transcript, called primary miRNA (pri-mRNA), base-pairs with itself, forming a stem-loop structure. Within the nucleus, an endonuclease enzyme, called Drosha, shortens the stem-loop structure into hairpin-shaped pre-miRNA. After the pre-miRNA...