Active regulation of the epidermal calcium profile

Adams, M. P., Mallet, D. G. and Pettet, G. J. (2012) Active regulation of the epidermal calcium profile. Journal of Theoretical Biology, 301 112-121. doi:10.1016/j.jtbi.2012.02.017


Author Adams, M. P.
Mallet, D. G.
Pettet, G. J.
Title Active regulation of the epidermal calcium profile
Journal name Journal of Theoretical Biology   Check publisher's open access policy
ISSN 0022-5193
1095-8541
Publication date 2012-05
Sub-type Article (original research)
DOI 10.1016/j.jtbi.2012.02.017
Volume 301
Start page 112
End page 121
Total pages 10
Place of publication London, United Kingdom
Publisher Academic Press
Language eng
Abstract A distinct calcium profile is strongly implicated in regulating the multi-layered structure of the epidermis. However, the mechanisms that govern the regulation of this calcium profile are currently unclear. It clearly depends on the relatively impermeable barrier of the stratum corneum (passive regulation) but may also depend on calcium exchanges between keratinocytes and extracellular fluid (active regulation). Using a mathematical model that treats the viable sublayers of unwounded human and murine epidermis as porous media and assumes that their calcium profiles are passively regulated, we demonstrate that these profiles are also actively regulated. To obtain this result, we found that diffusion governs extracellular calcium motion in the viable epidermis and hence intracellular calcium is the main source of the epidermal calcium profile. Then, by comparison with experimental calcium profiles and combination with a hypothesised cell velocity distribution in the viable epidermis, we found that the net influx of calcium ions into keratinocytes from extracellular fluid may be constant and positive throughout the stratum basale and stratum spinosum, and that there is a net outflux of these ions in the stratum granulosum. Hence, the calcium exchange between keratinocytes and extracellular fluid differs distinctly between the stratum granulosum and the underlying sublayers, and these differences actively regulate the epidermal calcium profile. Our results also indicate that plasma membrane dysfunction may be an early event during keratinocyte disintegration in the stratum granulosum.
Keyword Epidermis
Epithelium
Porous medium
Calcium profile
Calcium gradient
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Chemical Engineering Publications
 
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Created: Fri, 13 Sep 2013, 11:47:41 EST by Matthew Adams on behalf of School of Chemical Engineering