Molecular techniques for respiratory diseases: MicroRNA and extracellular vesicles

Abstract

miRNA are a class of evolutionarily conserved non-coding 19-to 22-nt regulatory RNA. They affect various cellular functions through modulating the transcriptional and post-transcriptional levels of their target mRNA by changing the stability of protein-coding transcripts or attenuating protein translation. miRNA were discovered in the early 1990s, and they have been the focus of new research in both basic and clinical medical sciences. Today, it has become clear that specific miRNA are linked to the pathogenesis of respiratory diseases, as well as cancer and cardiovascular disease. In addition, EV, including exosomes, which are small membrane-bound vesicles secreted by cells, were found to contain various functional miRNA that can be used for diagnostic and therapeutic purposes. As body fluids, such as blood and respiratory secretions, are major miRNA sources in the body, EV carrying extracellular miRNA are considered potentially useful for the diagnosis and assessment of pathological conditions, as well as the treatment of respiratory or other diseases. Although research in the field of lung cancer is actively progressing, studies in other respiratory fields have emerged recently as well. In this review, we provide an update in the topics of miRNA and EV focused on airway inflammatory diseases, such as asthma and COPD, and explore their potential for clinical applications on respiratory diseases.

Emerging role of extracellular vesicles in the respiratory system

“…COPD is also characterized by airway remodeling and skeletal muscle dysfunction and is often caused by smoking-induced airway inflammation 41 . An increased concentration of miR-210 was found in the bronchial epithelial cell-derived EVs of patients with COPD 42 .…”

“…EV-miR-145 has been identified as essential to epithelial and smooth muscle cell functions during asthma-induced inflammation 56 , 57 . During asthma, miR-145 is inhibited, preventing eosinophilic inflammation, mucous hypersecretion, Th2 cytokine production, and airway hyperresponsiveness, all of which are physiological responses to bronchial stress such as that induced by asthma 41 , 57 . However, over 140 other plasma and sputum EV-miRNAs have been found to promote asthma symptoms and asthma-associated damage.…”

‘Omics’: The new language in medicine that we all must learn

“…microRNA reviewed by Gon et al . is not directly responsible for protein synthesis but blocks RNA transcription . They do not act on a one‐to‐one inhibition but can influence many genes simultaneously and exerts a major influence on cell and organ function.…”

Expression Analysis of Muscle-Specific miRNAs in Plasma-Derived Extracellular Vesicles from Patients with Chronic Obstructive Pulmonary Disease

“…In this context, circulating microRNAs (miRNAs) and, particularly, miRNA embedded in extracellular vesicles (EV) are gaining a growing interest in the area of respiratory medicine [8].…”