Characterization of a novel three-dimensional outgrowth model of human bronchial mucosa

Recently it has been hypothesized that a reactivation of the epithelial-mesenchymal trophic unit (EMTU) of the respiratory mucosa, caused by extensive epithelial damage, may be responsible for the pathogenesis of asthma. However, most research on this subject so far has been limited by the unavailability of in vitro models correctly mimicking the three-dimensional architecture of the properly differentiated human bronchial mucosa. For this reason, we have developed a novel 3D outgrowth model, obtained from bronchial biopsies and composed of both human bronchial epithelial cells (goblet and columnar cells) and fibroblasts with their basement membrane. Here we present the preliminary data obtained by both SEM and TEM on the characterization of these bronchial outgrowths showing that cells and matrices within the 3D structures are well differentiated, presenting all the normal features of human bronchial mucosa such as microvilli, cilia, mucus, tight junctions, collagens etc. We also show the effects of medium-term treatment with cigarette smoke extracts in terms of cell survival and remodeling.