Breathing on Chip: Dynamic flow and stretch tune cellular composition and accelerate mucociliary maturation of airway epitheliumin vitro

Abstract

Human lung function is intricately linked to the mechanics of breathing; however, it remains unknown whether and how these mechanical cues shape human lung cellular biology. While respiration-related strains and fluid flows have been suggested to promote alveolar epithelial cell function, the study of such fundamental mechanisms in the conducting airway epithelium has been hindered by the lack of suitable in vitro airway models. Here, we developed a model of human bronchial airway epithelium using well-differentiated primary cell cultures on a commercial Organs-on-Chips platform that enables the application of breathing-associated airflow and cyclic strain. It furthermore features optional endothelial cell co-culture to allow for crosstalk with the vascular compartment. Using this model, we evaluated the impact of airflow and physiological levels of cyclic strain on airway epithelial cell differentiation and function. Our findings suggest that breathing-associated mechanical stimulation changes epithelial composition, reduces secretion of IL-8, and downregulates gene expression of matrix metalloproteinase 9, fibronectin, and other extracellular matrix (ECM) factors. These results indicate that breathing-associated forces are important modulators of airway epithelial cell biology and that their fine-tuned application could generate models of specific epithelial phenotypes and pathologies.

Primary Ciliary Dyskinesia Patient-Specific hiPSC-Derived Airway Epithelium in Air-Liquid Interface Culture Recapitulates Disease Specific Phenotypes In Vitro

“…Movies that did not contain analyzable bead signals due to debris or overgrowth were excluded. Trajectories were further analyzed to compute the average trajectory speed Uk and MCC coverage C k (the fraction of the FOV containing MCC) of each FOV k using customized code in Matlab (Mathworks), as reported previously [33]. For statistical analysis, the pooled FOV-averaged trajectory speed and MCC coverage values (the U k and C k for all k = 1 .…”

Isolating Bronchial Epithelial Cells from Resected Lung Tissue for Biobanking and Establishing Well-Differentiated Air-Liquid Interface Cultures

“…Another type of advancement seen in the field of airway biology for which isolated PBECs can be used is the use of Organs-on-Chips (OoC) technology 49 , 50 . Using this technology, the influence of the mechanical forces of breathing and blood flow, such as stretch, air, and medium flow, can be studied 29 .…”

Primary Ciliary Dyskinesia patient specific hiPSC-derived airway epithelium in Air Liquid Interface culture recapitulates disease specific phenotypesin vitro

“…Since functional MCC depends on many factors, including ciliary beat coordination and orientation [31,32], CBF alone is not a good predictor of MCC [33]. Indeed, visually comparing the ciliary beat in suspended cells of all conditions revealed metachronal and coordinated beat in non-PCD pALI and iALI cultures (Suppl.…”

“…Movies that did not contain analyzable bead signals due to debris or overgrowth were excluded. Trajectories were further analyzed to compute the average trajectory speed Uk and MCC coverage C k (the fraction of the FOV containing MCC) of each FOV k using customized code in Matlab (Mathworks), as reported previously [33]. For statistical analysis, For single-cell CBF measurements, the cell layer was dissociated by incubating the ALI cultures for 20 min in prewarmed Accutase TM in a conical tube.…”