ROCK dependent volume regulation of cell shape in confluent epithelial tissue

Epithelial volume regulation is a key component to tissue stability and dynamics. The cortical cytoskeleton plays an integral role in providing mechanical resistance to swelling and shrinkage due to changes in osmotic pressure. In this study, we describe the role of ROCK dependent volume regulation of confluent renal epithelial tissue It is well studied that single cells typically recover their volume in hyperosmotic conditions in under an hour. We show that while this remains true for small epithelial colonies, confluent epithelial height and volume are permanently decreased under hyperosmotic stress. This permanent decrease is dependent on sufficient ROCK activity as well as the presence of an intact tight junction.