Stratum corneum Lipid Function

Abstract

The stratum corneum contains a complex mixture of polar and nonpolar lipids in its intercellular spaces. These lipids, present in form of multiple lamellae, have been investigated for their role in providing the epidermal barrier to transcutaneous water loss, the selective barrier from the inside to the outside of the organism and partly the process of physiological desquamation. The composition of these lipids varies from species to species, with the body region and the degree of keratinocyte differentiation. The most undifferentiated layers of the epidermis contain typical membrane lipids, phospholipids, while more differentiated layers contain ceramides, cholesterol and free fatty acids. Essential fatty acids are essential for the maintenance of the lamellar structures and epidermal barrier function. Epidermal linoleic and arachidonic acids derive from exogenous sources. Only recently attempts have been made to elucidate the timing and regulation of epidermal fatty acid metabolism. Keratinocytes do not express a low molecular weight fatty acid binding protein like other cells active in lipid metabolism, but may employ alternative ways in fatty acid uptake and metabolism.

The Tape-Stripping Technique as a Method for Drug Quantification in Skin

“…In this way, increasing age is related to decreased skin thickness [98] and a variation in skin lipids [99] and flora [100]. The anatomical region also influences lipid distribution [101,102], microflora [103] and physical parameters such as TEWL [104]. However, there are already a few studies reporting conflicting results for the effect of gender [105] on skin physiology, as well as for the effect of anatomical site, pressure, pressure duration and tape removal rate in skin physiology [42], or the effect of skin transport technology, as iontophoresis, on human skin [106].…”

The natural marine anhydrophytosphingosine, Jaspine B, induces apoptosis in melanoma cells by interfering with ceramide metabolism

“…Also, some mammalian cells, specifically those in skin, intestines, and kidney, have been shown to contain a considerable amount of phytosphingosine-based SLs. In skin, phytosphingosine is a lipid occurring naturally in the stratum corneum, both in its free form and as part of the major fraction of ceramides [34]. However, the effect of phytosphingosine on melanoma development has never been examined.…”

Epidermal differentiation and keratin gene expression

“…Several other changes occur in the later stages of differentiation. Membrane-coating granules, made ear lier, fuse with the plasma membrane and release lipids into intercellular spaces of granular and stratum comeum cells (for a review, see Schurer et al, 1991). In addition, gluta mine-and lysine-rich proteins are deposited on the inner surface of the plasma membrane (Rice and Green, 1979).…”