title: Computational modelling of epidermal stratification highlights the importance of asymmetric cell division for predictable and robust layer formation.
abstract: Skin is a complex organ tasked with, among other functions, protecting the body from the outside world. Its outermost protective layer, the epidermis, is comprised of multiple cell layers that are derived from a single-layered ectoderm during development. Using a new stochastic, multi-scale computational modelling framework, the anisotropic subcellular element method, we investigate the role of cell morphology and biophysical cell-cell interactions in the formation of this layered structure. This three-dimensional framework describes interactions between collections of hundreds to thousands of cells and (i) accounts for intracellular structure and morphology, (ii) easily incorporates complex cell-cell interactions and (iii) can be efficiently implemented on parallel architectures. We use this approach to construct a model of the developing epidermis that accounts for the internal polarity of ectodermal cells and their columnar morphology. Using this model, we show that cell detachment, which has been previously suggested to have a role in this process, leads to unpredictable, randomized stratification and that this cannot be abrogated by adjustment of cell-cell adhesion interaction strength. Polarized distribution of cell adhesion proteins, motivated by epithelial polarization, can however eliminate this detachment, and in conjunction with asymmetric cell division lead to robust and predictable development.
authors.affiliation: Center for Mathematical and Computational Biology, Department of Mathematics, University of California, Irvine, CA 92617, USA Center for Complex Biological Systems, University of California, Irvine, CA 92617, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Gord
authors.affiliation: Center for Mathematical and Computational Biology, Department of Mathematics, University of California, Irvine, CA 92617, USA Center for Complex Biological Systems, University of California, Irvine, CA 92617, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Holmes
authors.affiliation: Center for Complex Biological Systems, University of California, Irvine, CA 92617, USA Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92617, USA.
authors.forename: Xing
authors.initials: X
authors.lastname: Dai
authors.affiliation: Center for Mathematical and Computational Biology, Department of Mathematics, University of California, Irvine, CA 92617, USA Center for Complex Biological Systems, University of California, Irvine, CA 92617, USA qnie@uci.edu.
authors.forename: Qing
authors.initials: Q
authors.lastname: Nie
mesh_terms: D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D019295:Computational Biology / Q000379:methods*; D003198:Computer Simulation; D000078404:Epidermal Cells; D004817:Epidermis / Q000254:growth & development*; D008954:Models, Biological; D013997:Time Factors
keywords: anisotropic subcellular element method; asymmetric division; computational biology; epidermal development; polarity
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