title: Monolayer stress microscopy: limitations, artifacts, and accuracy of recovered intercellular stresses.
abstract: In wound healing, tissue growth, and certain cancers, the epithelial or the endothelial monolayer sheet expands. Within the expanding monolayer sheet, migration of the individual cell is strongly guided by physical forces imposed by adjacent cells. This process is called plithotaxis and was discovered using Monolayer Stress Microscopy (MSM). MSM rests upon certain simplifying assumptions, however, concerning boundary conditions, cell material properties and system dimensionality. To assess the validity of these assumptions and to quantify associated errors, here we report new analytical, numerical, and experimental investigations. For several commonly used experimental monolayer systems, the simplifying assumptions used previously lead to errors that are shown to be quite small. Out-of-plane components of displacement and traction fields can be safely neglected, and characteristic features of intercellular stresses that underlie plithotaxis remain largely unaffected. Taken together, these findings validate Monolayer Stress Microscopy within broad but well-defined limits of applicability.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA. dhananjay@alumni.brown.edu
authors.forename: Dhananjay T
authors.initials: DT
authors.lastname: Tambe
authors.forename: Ugo
authors.initials: U
authors.lastname: Croutelle
authors.forename: Xavier
authors.initials: X
authors.lastname: Trepat
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Park
authors.forename: Jae Hun
authors.initials: JH
authors.lastname: Kim
authors.forename: Emil
authors.initials: E
authors.lastname: Millet
authors.forename: James P
authors.initials: JP
authors.lastname: Butler
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fredberg
mesh_terms: D000465:Algorithms; D016477:Artifacts; D018929:Cell Culture Techniques; D008853:Microscopy / Q000379:methods* / Q000592:standards*; D015233:Models, Statistical; D012680:Sensitivity and Specificity; D013312:Stress, Physiological