Exosomes from Eosinophils of Asthmatic Patients Produce Functional Alterations on Structural Lung Cells

Rationale: : Exosomes are nanovesicles that play an important role in intercellular communication releasing diverse molecules (RNA, miRNAs, proteins and lipidic mediators). Recently, our group has described that eosinophils from asthmatic subjects release exosomes. The aim of this study is to investigate the effect of eosinophil exosomes from asthmatics patients in structural lung cells.

Methods: The study was performed in two types of structural lung cells: Bronchial Smooth Muscle Cells (BSMCs) and Small Airway Epithelial Cells (SAECs). These cells were cultured with exosomes, previously purified from eosinophils from asthmatic and healthy individuals, and functional studies were carried out: apoptosis, necrosis, wound healing assays and also, we analyzed relative gene expression of important genes in asthma pathology (TSLP, Periostin, TGF-b, TNF-a, MMP9, VEGF and CCR3, CCL26, TLR3, NFkb)

Results: When BSMCs were cultured in the presence of exosomes at different times, apoptosis/necrosis rate and relative gene expression showed changes compared to cells without exosomes. The rate of apoptosis and necrosis in structural lung cells was higher in presence of exosomes, being its maximum rate at 24h. Similarly, when SAECs were cultured in the presence of exosomes, they needed more time to close the wound completely than SAECs without exosomes. Regarding the relative gene expression, we observed that the profile of gene expression is different between cells with or without exosomes.

Conclusions: The presence of exosomes from eosinophils of asthmatic alter the functionality of bronchial smooth muscle cells and airways epithelial cells.