title: The study of polarisation in single cells using model cell membranes.
abstract: The apicobasal polarisation of epithelial cells within an epithelium is critical for its function as a selective barrier. Microenvironmental parameters, including cell-matrix and cell-cell interactions, contribute to the initiation and orientation of this polarity. However, it is often non-trivial to decipher the differential effects of these parameters in a controlled manner using traditional in vitro platforms. A reductionist platform, consisting of E-cadherin coupled onto laterally mobile supported lipid bilayers, was utilised to mimic E-cadherin presentation in the cell membrane. These functionalised bilayers were generated either on flat 2D surfaces or the interior surfaces of round microwells. This platform enabled the study of E-cadherin adhesion and the initiation of polarisation in a controlled environment, where the dimensionality of the microenvironment, type of protein coating and cell shape could be independently studied. A high proportion of single epithelial cells interacted with and clustered cellular E-cadherin in the presence of E-cadherin functionalised bilayers, which was reduced in the presence of integrin-mediated adhesion. The differential response in E-cadherin clustering correlated with the polarisation of E-cadherin and Na,K-ATPase, a reporter for the induction of basolateral polarity. Neither the three-dimensional presentation of E-cadherin nor the cell shape affected E-cadherin clustering or polarisation in single cells. Thus, the mobile presentation of E-cadherin was sufficient to mimic a cell-cell contact and induce basolateral polarisation in single cells.
authors: Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Zurich, Switzerland. mirren.charnley@mat.ethz.ch
authors: Mirren
authors: M
authors: Charnley
authors: Ruth
authors: R
authors: Kroschewski
authors: Marcus
authors: M
authors: Textor
mesh_terms: D000818:Animals; D015820:Cadherins / Q000378:metabolism; D018929:Cell Culture Techniques; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology* / Q000201:enzymology; D008051:Lipid Bilayers / Q000378:metabolism; D061985:Madin Darby Canine Kidney Cells; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D015820:Cadherins; D008051:Lipid Bilayers; D000254:Sodium-Potassium-Exchanging ATPase