Uniaxial stretching device for studying maturity-dependent morphological response of epithelial cell monolayers to tensile strain

Immature cell monolayers are vulnerable to tensile strain, which can cause severe diseases including fibrosis, cancer, and atherosclerosis. However, little is known about how immature cell monolayers respond to tensile strain. To study the effect of tensile strain on the morphology of cells in immature monolayers, we developed a miniaturized stretching device that allows stable real-time imaging of changes in cell shape induced by uniaxial static stretching of up to 20%. Upon stretching, the shape of cells in the immature (2 day-cultured) monolayer changed dynamically, unlike in the mature (7 day-cultured) monolayer. Dynamic changes in the immature cell monolayers induced by tensile strain can be explained by the increase in di-phosphorylated myosin light chain (pp-MLC), which initiates actomyosin contraction. We suggest that our stretching-observation system can be used to investigate the morphological response of epithelial cell monolayers to tensile strain.