title: Mechanical Characterization of Microengineered Epithelial Cysts by Using Atomic Force Microscopy.
abstract: Most organs contain interconnected tubular tissues that are one-cell-thick, polarized epithelial monolayers enclosing a fluid-filled lumen. Such tissue organization plays crucial roles in developmental and normal physiology, and the proper functioning of these tissues depends on their regulation by complex biochemical perturbations and equally important, but poorly understood, mechanical perturbations. In this study, by combining micropatterning techniques and atomic force microscopy, we developed a simple in vitro experimental platform for characterizing the mechanical properties of the MDCK II cyst, the simplest model of lumen-enclosing epithelial monolayers. By using this platform, we estimated the elasticity of the cyst monolayer and showed that the presence of a luminal space influences cyst mechanics substantially, which could be attributed to polarization and tissue-level coordination. More interestingly, the results from force-relaxation experiments showed that the cysts also displayed tissue-level poroelastic characteristics that differed slightly from those of single cells. Our study provides the first quantitative findings, to our knowledge, on the tissue-level mechanics of well-polarized epithelial cysts and offers new insights into the interplay between cyst mechanics and cyst physiology. Moreover, our simple platform is a potentially useful tool for enhancing the current understanding of cyst mechanics in health and disease.
authors.affiliation: Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong.
authors.forename: Dongshi
authors.initials: D
authors.lastname: Guan
authors.affiliation: Institute of Industrial Science (IIS), The University of Tokyo, Tokyo, Japan.
authors.forename: Daniela
authors.initials: D
authors.lastname: Serien
authors.affiliation: Institute of Industrial Science (IIS), The University of Tokyo, Tokyo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Takeuchi
authors.affiliation: Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong; Department of Physics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong. Electronic address: penger@ust.hk.
authors.forename: Penger
authors.initials: P
authors.lastname: Tong
authors.affiliation: Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong; Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong. Electronic address: eelyobas@ust.hk.
authors.forename: Levent
authors.initials: L
authors.lastname: Yobas
authors.affiliation: Division of Biomedical Engineering, The Hong Kong University of Science and Technology, Kowloon, Hong Kong; Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong; the State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong. Electronic address: bohuangp@ust.hk.
authors.forename: Pingbo
authors.initials: P
authors.lastname: Huang
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D060846:Cell Engineering; D004285:Dogs; D004548:Elasticity; D004847:Epithelial Cells / Q000166:cytology*; D061985:Madin Darby Canine Kidney Cells; D018625:Microscopy, Atomic Force; D055616:Microtechnology