Mathematical model for calcium-assisted epidermal homeostasis

Abstract

Using a mathematical model of the epidermis, we propose a mechanism of epidermal homeostasis mediated by calcium dynamics. We show that calcium dynamics beneath the stratum corneum can reduce spatio-temporal fluctuations of the layered structure of the epidermis. We also demonstrate that our model can reproduce experimental results that the recovery from a barrier disruption is faster when the disrupted site is exposed to air. In particular, simulation results indicate that the recovery speed depends on the size of barrier disruption.

Type XVII collagen coordinates proliferation in the interfollicular epidermis

“…To explain the transient epidermal hyperproliferation of the Col17a1 −/− neonatal IFE, we exploited an in silico model (Kobayashi et al, 2016) to recapitulate the epidermal development. As COL17 serves as a linker between the epidermis and dermis and is expressed in basal cells, most of which are committed progenitor cells in the epidermis (Doupé and Jones, 2012; Lim et al, 2013), epidermal thickness was calculated upon the loosening of the attachment of committed progenitor cells to the BMZ.…”

“…The authors Y. K. and M. N. previously introduced a mathematical model that could simulate the homeostasis of the epidermis (Kobayashi et al, 2016). In this model, the four epidermal processes were taken into account: (i) the kinetic interactions of epidermal cells, (ii) the reproduction of stem cells and daughter cells, (iii) differentiation, and (iv) calcium dynamics.…”

“…The differentiation processes and calcium dynamics were the same as in the manuscript (Kobayashi et al, 2016), which were summarized as follows: each suprabasal cell was assigned a degree of differentiation $S$ as an internal variable. When $S$ reached the threshold $S^{*}$, the cell underwent terminal differentiation and became a cornified cell.…”

Model for calcium-mediated reduction of structural fluctuations in epidermis

“…Motivated by these observations, we have recently proposed a mathematical model of the epidermis, which has revealed that calcium dynamics can stabilize the structure of the SC [5,6]. This model was based on particle dynamics for cell movements and reactiondiffusion process for calcium dynamics, where individual cells are assigned the degree of differentiation as an inner variable, which is affected by calcium dynamics.…”

A 3D self-organizing multicellular epidermis model of barrier formation and hydration with realistic cell morphology based on EPISIM

“…We use a cell-centred agent-based modelling approach to encompass the life-history of individual cells in their 3D environment. This approach has been used previously to model several aspects of epidermal biology, ranging from simple keratinocyte cultures1516, to models of tissue homeostasis17181920. However, 3D cell-centred agent-based models oversimplify keratinocyte morphology with spheres – an approximation that falls apart for cells in the stratum granulosum (SG) and particularly for the stratum corneum (SC): Here, cells typically measure 30 μm in length and width, but less than 1 μm in height10.…”