Long and very long lamellar phases in model stratum corneum lipid membranes.

Abstract

Membrane models of the stratum corneum (SC) lipid barrier, either healthy or affected by recessive X-linked ichthyosis, constructed from ceramide [Cer; nonhydroxyacyl sphingosine N-tetracosanoyl-d-erythro-sphingosine (CerNS24) alone or with omega-O-acylceramide N-(32-linoleyloxy)dotriacontanoyl-d-erythro-sphingosine (CerEOS)], FFAs(C16-24), cholesterol (Chol), and sodium cholesteryl sulfate (CholS) were investigated. X-ray diffraction (XRD) revealed a previously unreported polymorphism of the membranes. In the absence of CerEOS, the membranes formed a short lamellar phase (SLP; the repeat distance d = 5.3 nm), a medium lamellar phase (MLP; d = 10.6 nm), or very long lamellar phases (VLLP; d = 15.9 and 21.2 nm). An increased CholS-to-Chol ratio modulated the membrane polymorphism, although the CholS phase separated at ≥ 7 weight% (of total lipids). The presence of CerEOS led to the stable long lamellar phase (LLP) with d = 12.2 nm and prevented VLLP formation. Our XRD results agree well with recently published cryo-electron microscopy data for vitreous skin sections, while also revealing new structures. Thus, lamellar phases with long repeat distances (MLP and VLLP) may be formed in the absence of omega-O-acylceramide, whereas these ultralong Cer species likely stabilize the final SC lipid architecture of LLP by riveting the adjacent lipid layers.

• Authors: Petra Pullmannová, Elena Ermakova, Andrej Kováčik, Lukáš Opálka, Jaroslav Maixner, Jarmila Zbytovská, Norbert Kučerka, Kateřina Vávrová
• Journal: Journal of lipid research (J Lipid Res) Vol. 60 Issue 5 Pg. 963-971 (05 2019) ISSN: 1539-7262 [Electronic] United States
• PMID: 30885924 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 Pullmannová et al.

Chemical References

• Membrane Lipids

Topics

• Cryoelectron Microscopy
• Humans
• Ichthyosis, X-Linked (genetics, metabolism, pathology)
• Membrane Lipids (chemistry, metabolism)
• Models, Biological
• Skin (chemistry, metabolism, pathology)