Monounsaturated Fatty Acids Reduce the Barrier of Stratum Corneum Lipid Membranes by Enhancing the Formation of a Hexagonal Lateral Packing

Abstract

The effectiveness of the skin barrier underlies the outer layer of the skin: the stratum corneum (SC). However, in several skin diseases this barrier is impaired. In two inflammatory skin diseases, atopic eczema and Netherton syndrome, an increased level of monounsaturated fatty acids (MUFAs) has been observed as opposed to healthy skin. In the present study, we aimed to investigate the effect of MUFAs on the lipid organization and skin lipid barrier using an in vitro model membrane system, the stratum corneum substitute (SCS), mimicking the SC lipid composition and organization. To achieve our goal, the SCS has been prepared with increasing levels of MUFAs using various chain length. Permeation studies and trans-epidermal water loss measurements show that an increment of MUFAs reduces the lipid barrier in the SCS. The increased level of unsaturation exerts its effect by reducing the packing density in the lipid organization, while the lamellar phases are not affected. Our findings indicate that increased levels of MUFAs may contribute to the impaired skin barrier in diseased skin.

Effect of monoglycerides and fatty acids on a ceramide bilayer

“…There are two proposed mechanisms of action of lipidic penetration enhancers: lipid fluidisation and lipid phase separation. The first one involves disruption of the highly ordered SC lipid matrix, thereby increasing the diffusion of drugs 22,25,73,74 and the second one proposes that the enhancer forms a separate domain within the lipid phase which acts as permeable defects of the skin barrier. 22,24,73,75 In our simulations we have not observed any lipid phase separation; in all the studies oils are found to be completely miscible with the ceramides.…”

Exploring the potentials of nurture: 2nd and 3rd generation explant human skin equivalents

“…Only a hexagonal lateral packing was observed in the 2 nd and 3 rd generation outgrowths, similar to other epidermal and full thickness HSEs [12,[25][26][27]. The abundant formation of a hexagonal packing in culture may be explained by: a reduction in SC FFAs levels and in their chain lengths or by an increase in the relative levels of MUFAs [28].…”

“…In contrast to the lateral packing, the LPP repeat distance can be maintained in all three Ex-HSE generations. Studies using model lipid systems also suggest that increased levels of MUFAs mainly affects the lateral packing while the lamellar phases are not changed [28].…”

Psoriasis-Associated Late Cornified Envelope (LCE) Proteins Have Antibacterial Activity

“…In short, SC was isolated from ex vivo ski or 3D epidermal equivalents and used in the diffusion set-up was described previously (Mojumdar et al , 2014) using 0.34 mg/ml hydrocortisone in acetate buffer (pH 5.0) as diffusion fluid with 2–2,5 ml/hour flow speed. Samples were collected for a period of 15 hours, with a sampling time of 60 minutes.…”