Extracellular Vesicles from Airway Secretions: New Insights in Lung Diseases

Abstract

Lung diseases (LD) are one of the most common causes of death worldwide. Although it is known that chronic airway inflammation and excessive tissue repair are processes associated with LD such as asthma, chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis (IPF), their specific pathways remain unclear. Extracellular vesicles (EVs) are heterogeneous nanoscale membrane vesicles with an important role in cell-to-cell communication. EVs are present in general biofluids as plasma or urine but also in secretions of the airway as bronchoalveolar lavage fluid (BALF), induced sputum (IS), nasal lavage (NL) or pharyngeal lavage. Alterations of airway EV cargo could be crucial for understanding LD. Airway EVs have shown a role in the pathogenesis of some LD such as eosinophil increase in asthma, the promotion of lung cancer in vitro models in COPD and as biomarkers to distinguishing IPF in patients with diffuse lung diseases. In addition, they also have a promising future as therapeutics for LD. In this review, we focus on the importance of airway secretions in LD, the pivotal role of EVs from those secretions on their pathophysiology and their potential for biomarker discovery.

Side-Directed Release of Differential Extracellular Vesicle-associated microRNA Profiles from Bronchial Epithelial Cells of Healthy and Asthmatic Subjects

“…According to the results of the NanoFCM particle characterization, EV populations isolated from the apical cell side were mainly composed of vesicles with diameters matching the size range of the exosomes. Contrarily, on the basolateral cell side, median vesicle diameters were noticeably larger, consistent rather with the size of the microvesicles than with the exosomes [37,38]. FACS analysis for exosomal marker proteins revealed the presence of exosomes in both apical and basolateral samples, although apical EVs seemed to express exosomal marker proteins to a greater extent than the basolateral vesicles.…”

Exosomal Micro-RNAs as Intercellular Communicators in Idiopathic Pulmonary Fibrosis

“…Besides, the membrane composition of EVs is highly dynamic, heterogeneous and dependent on the cellular source and environmental conditions [ 50 ]. EVs are released by almost all cell types such as platelets, tumor cells, dendritic cells, T and B lymphocytes, eosinophils, epithelial cells, endothelial cells, and mesenchymal stem cells (MSCs) [ 51 ]. Currently, some databases on EV composition as EVpedia, Exocarta and Vesiclepedia [ 52 , 53 , 54 ] include the most recent information about their composition.…”

Current and prospective applications of exosomal microRNAs in pulmonary fibrosis (Review)

“…Although BALF analysis is the most commonly used technique for the assessment IPF, induced sputum has been regarded as a safer and less invasive method and has been shown to be clinically valuable for respiratory diseases ( 110 , 111 ). Previous research has demonstrated that the expression and production of proteins, such as insulin-like growth factor binding protein 2, IL-8 and MMP-7 in the sputum of patients with IPF is significantly increased, which may be related to the disease ( 112 ).…”