Boeglin et al., "Lipoxygenases mediate the effect of essential fatty acid in skin barrier formation: A proposed role in releasing omega-hydroxyceramide for construction of the corneocyte
lipid envelope," The Journal of Biological Chemistry, vol.
At the transition to the SC, the polymer is processed to the monomer by proteases such as Prss8 and SASPase [28, 29] and then binds to keratin and forms the fundamental structure of the corneocytes
. At the outermost layer of the SC, FLG is citrullinated by peptidylarginine deiminase and then dissociated from keratin filaments .
* The corneocytes
are expanded in soft cerumen, but not in hard cerumen.
When discussing with parents how the protective barrier functions considering the strateum corneum as a brick wall with the corneocytes
as bricks and the lipids as cement can be a useful analogy to illustrate how the decreased barrier function of the corneum stratum makes an infant's skin more permeable and inclined to dryness (Elias, 1996).
Genetic disorders of keratinisation may lead to the production of defective corneocytes
, which detach easily such as in ichthyosis (Figure 2).
Indeed, surfactants remove lipids and denaturate corneocyte
proteins, thus revealing sites available for staining deposition and transient corneocyte
edema as well .
The reason for this is not clear, but one theory is that the increase in corneocyte
surface area seen in elderly skin may cause increased stratum corneum water transit times.
clusters are bundles of cemented keratin filaments, which have retained a large degree of cohesion with one another and detach as such from the surface of the stratum corneum.
It was first proposed 3 decades ago and now is widely appreciated that the structure of the stratum corneum is analogous to that of a brick wall, with corneocyte
"bricks" held in place by the extracellular matrix "mortar." (1-3) The stratum corneum barrier relies predominantly on the extracellular matrix, where lamellar bilayers block the outflow of water into the environment and prevent the ingress of toxic substances, allergens, and microbial pathogens into the body.
"Our objective was the construction of a three-dimensional model of the stratum corneum, corneocyte
arrangements and lipid pathlengths," said Dr.
Diffusion is modeled as a two-dimensional random walk through the biphasic (lipid and corneocyte
) stratum corneum.