IL-13 Augments Compressive Stress–Induced Tissue Factor Expression in Human Airway Epithelial Cells

Abstract

Tissue factor (TF) is best known as a cellular initiator of coagulation, but it is also a multifunctional protein that has been implicated in multiple pathophysiologic conditions, including asthma. In the lung, airway epithelial cells express TF, but it is unknown how TF expression is regulated by asthma-associated mediators. We investigated the role of IL-13, a type 2 cytokine, alone and in combination with compressive stress, which mimics asthmatic bronchoconstriction, on TF expression and release of TF-positive extracellular vesicles from primary normal human bronchial epithelial cells. Well-differentiated normal human bronchial epithelial cells were treated with IL-13 and compressive stress, alone and in combination. TF mRNA, protein and activity were measured in the cells and conditioned media. TF was also measured in the bronchoalveolar lavage (BAL) fluid of allergen-challenged mice and patients with asthma. IL-13 and compressive stress increased TF expression, but only compressive stress induced TF-positive extracellular vesicle release. Pretreatment with IL-13 augmented compressive stress-induced TF expression and release. TF protein and activity in BAL fluid were increased in allergen-sensitized and -challenged mice. TF was elevated in the BAL fluid of patients with mild asthma after an allergen challenge. Our in vitro and in vivo data indicate close cooperation between mechanical and inflammatory stimuli on TF expression and release of TF-positive extracellular vesicles in the lungs, which may contribute to pathophysiology of asthma.Keywords: asthma; bronchoconstriction; mechanotransduction; coagulation; airway epithelium Clinical RelevanceTwo critical components of asthma-IL-13 and bronchoconstriction-cooperatively work to induce tissue factor (TF) expression and release of TF-positive extracellular vesicles from well-differentiated human bronchial epithelial cells. Furthermore, in both mice and humans, allergen challenge increases the release of TF into bronchoalveolar lavage fluid.Asthma is characterized by chronic airway inflammation and airway hyperresponsiveness (1, 2). Although the immune system is certainly implicated in asthma, a growing body of evidence suggests that airway epithelial cells also initiate and perpetuate disease (3, 4). During asthma exacerbations, airway smooth muscle contracts excessively and the airway becomes narrowed, resulting in buckling of the airway epithelium (5, 6). Epithelial cells in such buckled airways are subjected to a compressive mechanical stress of approximately 30 cm H 2 O (7). Using an in vitro system mimicking the Correspondence and requests for reprints should be addressed to Jin

Genomic signatures of the unjamming transition in compressed human bronchial epithelial cells

“…Our analysis linked, at the genomic level, the response of non-asthmatic HBEC to pressure both to the UJT and the tissue remodeling in asthmatic airways. We identified common genomic patterns that induce ECM remodeling in both asthmatic and nonasthmatic unjammed HBECs, thus suggesting at the molecular level a connection between airway remodeling, bronchoconstriction and UJT as described in previous studies 21,26,27,29,36,37,91,97 .…”

“…HBECs, grew them to confluence under Air Liquid Interface (ALI), and then exposed them to an apico-to-basal pressure difference of 30 cm H2O 15,26,29,30,[36][37][38] (see Materials and Methods). Following the same experimental protocol described in Kılıç et al 30 , this pressure was maintained for 3 hours and then released ( Fig.…”

“…During bronchoconstriction, the airway becomes extensively narrowed and contracted, and airway caliber is reduced 89 , resulting in excessive mechanical compression of the epithelial layer 90 (similar to ~30 cm H2O compression). A similar compression applied in our experimental system recapitulates key anatomic and pathophysiologic features as shown during asthmatic bronchoconstriction 23,24,26,29,37,91 , so we investigated the potential existence of common molecular components involved in the unjamming of both asthmatic and compressed normal epithelial cells. To achieve this task, we assessed the transcriptional profile of ALI-cultured HBECs from four asthmatic donors through bulk RNA-Seq.…”

In primary airway epithelial cells, the unjamming transition is distinct from the epithelial-to-mesenchymal transition

“…Finally, we have established in previous reports that pathologic responses increase with increasing compressive stress but exhibit a maximum response at 20-30 cm H 2 O. These pathologic responses include asthmatic airway remodeling [81][82][83][84][85][86][87][88][89][90] and a robust UJT [37][38][39] .…”

Irradiation Induces Epithelial Cell Unjamming

“…Informed consent was obtained from authorized representatives of all organ donors. As previously described (Park et al, 2015;Mitchel et al, 2016), HBE cells were seeded on transwells coated with 0.05 mg/ml rat tail collagen 1 and maintained in ALI culture until the cells were well-differentiated as determined by immunofluorescent staining for goblet cells marked for MUC5AC, ciliated cells marked for FOXJ1 and b4-tubulin, and basal cells marked for p63α ( Figure 2D).…”