Breathing on Chip: Biomechanical forces change airway epithelial cell biology ina human Airway Lung-Chip

Abstract

Human lung function is intricately linked to blood flow and breathing cycles, but it remains unknown how these dynamic cues shape human airway epithelial biology. Here we report a state-of-the-art protocol for studying effects of physiological airflow and stretch on differentiation, cellular composition, and mucociliary clearance of human primary airway epithelial cells cultured on a perfused airway chip. Perfused epithelial tissue cultures developed a large airway-like cellular composition with accelerated maturation and polarization of mucociliary clearance when compared to traditional (static) culture methods. Additional application of airflow and stretch to the airway chip resulted in a cellular composition more comparable to the small(er) airways, reduced baseline secretion of interleukin-8 and other inflammatory proteins, and reduced gene expression of matrix metalloproteinase (MMP) 9, fibronectin, and other extracellular matrix factors. These results indicate that breathing-like mechanical stimuli are important modulators of airway epithelial cell differentiation and homeostasis and that their fine-tuned application could generate models of specific epithelial regions, pathologies, and mucociliary (dys)function.