Unjamming and cell shape in the asthmatic airway epithelium

Epithelial cells are mostly quiescent when they are mature and uninjured, but they undergo collective migration during morphogenesis, cancer metastasis, and wound repair. We have recently reported (Nature Materials, Park et al, 2015) that, during differentiation, airway epithelial cells in air-liquid interface culture undergo a transition from a fluid-like, mobile “unjammed” state toward a solid-like, immobile “jammed” state. This transition toward the jammed state is substantially delayed in cells from asthmatic donors, compared with cells from normal donors. Furthermore, mature, jammed cells undergo a transition toward the unjammed state when they are subjected to compressive stress that mimics bronchoconstriction, a process that occurs during asthma exacerbations. These jamming and unjamming transitions are accompanied by unique changes in cell shape that are associated with intercellular forces.