The stratum corneum represents the first skin barrier against chemical and physical damage. These unique properties are based on its peculiar lipid composition with ceramides (CERs) as the main protagonists. In this study, the structural and chemical properties of the α-OH phytosphingosine [AP] CER class have been investigated. α-OH CERs are present in the stratum corneum in their d-forms; however, in most model systems the diastereomer mixture with the synthetically produced l-form is used. The d-form is well-known to form a hydrogen bonding network that helps to reduce the permeability of the lipid matrix, while the l-form does not show any hydrogen bonding network formation. In this paper, 2D (monolayers) and 3D (aqueous dispersions) models have been used to thoroughly study the physical-chemical behaviors of CER[AP] diastereomers taking into account how the symmetry of the chain pattern influences the behavior of the molecules. The chains of both diastereomers arrange in an oblique unit cell, but only the d-CER[AP] forms a supramolecular lattice (subgel phase) in both model systems. Interestingly, the chain pattern does not play any role in structure formation since the hydrogen bonding network dictates the packing properties. The 1:1 mixture of the diastereomers phase separates into two domains: one is composed of practically pure d-form and the other one is composed of a mixture of the l-form with a certain amount of d-form molecules.

• MeSH
• ceramidy * MeSH
• epidermis MeSH
• kůže * MeSH
• sfingosin analogy a deriváty   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ceramidy * MeSH
• phytosphingosine MeSH Prohlížeč
• sfingosin MeSH

INTRODUCTION: The pathogenesis of preterm labor is fragmentarily explained. The most widely accepted theory points out to infection and inflammation as possible causes, which can be mediated by potentially different factors, including sphingolipid mediators. Sphingolipids are a class of lipids that have been shown as important mediators in various cell processes such as: proliferation, growth, apoptosis, stress response, necrosis and inflammation. The aim of the study was to assess plasma concentrations of selected sphingolipids in patients with preterm labor. MATERIAL AND METHODS: We used ultra-high performance liquid chromatography with triple mass spectrometry (UHPLC-ESI-MS/MS) to assess plasma concentrations of the 11 sphingolipids in patients presenting with symptoms of preterm labor (n=61) and threatened preterm labor (n=40). RESULTS: We observed a statistically significant increase (p-value<0.004) in plasma concentrations of C16-Cer in patients with preterm labor as compared to the control group. We also found C16-Cer to be the best predictor of preterm labor in the group of patients with symptoms occurring after 32 weeks of gestation. CONCLUSIONS: Our findings show a possible involvement of selected sphingolipids, especially C16-Cer, in the pathogenesis of preterm labor. Their role as predictors of preterm delivery needs to be validated in the future on larger group of patients.

• Klíčová slova
• C16 ceramide, Inflammation, Preterm labor, Sphingolipids,
• MeSH
• biologické markery krev   MeSH
• ceramidy krev   MeSH
• dospělí MeSH
• gestační stáří MeSH
• lidé MeSH
• novorozenec nedonošený MeSH
• předčasná porodní činnost krev   diagnóza   patofyziologie   MeSH
• senzitivita a specificita MeSH
• studie případů a kontrol MeSH
• tandemová hmotnostní spektrometrie MeSH
• těhotenství MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biologické markery MeSH
• ceramidy MeSH
• N-palmitoylsphingosine MeSH Prohlížeč

Omega-O-acyl ceramides such as 32-linoleoyloxydotriacontanoyl sphingosine (Cer[EOS]) are essential components of the lipid skin barrier, which protects our body from excessive water loss and the penetration of unwanted substances. These ceramides drive the lipid assembly to epidermal-specific long periodicity phase (LPP), structurally much different than conventional lipid bilayers. Here, we synthesized Cer[EOS] with selectively deuterated segments of the ultralong N-acyl chain or deuterated or 13C-labeled linoleic acid and studied their molecular behavior in a skin lipid model. Solid-state 2H NMR data revealed surprising molecular dynamics for the ultralong N-acyl chain of Cer[EOS] with increased isotropic motion toward the isotropic ester-bound linoleate. The sphingosine moiety of Cer[EOS] is also highly mobile at skin temperature, in stark contrast to the other LPP components, N-lignoceroyl sphingosine acyl, lignoceric acid, and cholesterol, which are predominantly rigid. The dynamics of the linoleic chain is quantitatively described by distributions of correlation times and using dynamic detector analysis. These NMR results along with neutron diffraction data suggest an LPP structure with alternating fluid (sphingosine chain-rich), rigid (acyl chain-rich), isotropic (linoleate-rich), rigid (acyl-chain rich), and fluid layers (sphingosine chain-rich). Such an arrangement of the skin barrier lipids with rigid layers separated with two different dynamic "fillings" i) agrees well with ultrastructural data, ii) satisfies the need for simultaneous rigidity (to ensure low permeability) and fluidity (to ensure elasticity, accommodate enzymes, or antimicrobial peptides), and iii) offers a straightforward way to remodel the lamellar body lipids into the final lipid barrier.

• Klíčová slova
• NMR spectroscopy, lipid assembly, lipid chain order, long periodicity phase, molecular dynamics, neutron diffraction, stratum corneum models,
• MeSH
• ceramidy chemie   MeSH
• epidermis MeSH
• kůže chemie   MeSH
• kyselina linolová * MeSH
• sfingosin analýza   MeSH
• simulace molekulární dynamiky * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ceramidy MeSH
• kyselina linolová * MeSH
• sfingosin MeSH

Gentiana lutea is a bitter herb that is traditionally used to improve gastric disorders. Recently, we have shown that Gentiana lutea extract (GE) also modulates the lipid metabolism of human keratinocytes in vitro and in vivo. In the present study, we investigated the role of GE on ceramide synthesis in human primary keratinocytes (HPKs) and psoriasis-like keratinocytes. We could demonstrate that GE increased the concentrations of glucosylceramides and the ceramide AS/AdS subclass without affecting the overall ceramide content in HPKs. The expression of ceramide synthase 3 (CERS3) and elongases (ELOVL1 and 4) was reduced in psoriasis lesions compared to healthy skin. Psoriasis-like HPKs, generated by stimulating HPKs with cytokines that are involved in the pathogenesis of psoriasis (IL-17, TNF-α, IL-22 and IFN-γ) showed increased levels of IL-6, IL-8 and increased expression of DEFB4A, as well as decreased expression of ELOVL4. The treatment with GE partly rescued the reduced expression of ELOVL4 in psoriasis-like HPKs and augmented CERS3 expression. This study has shown that GE modulates ceramide synthesis in keratinocytes. Therefore, GE might be a novel topical treatment for skin diseases with an altered lipid composition such as psoriasis.

• Klíčová slova
• CerS, ELOVL, Gentiana lutea, ceramides, skin,
• MeSH
• ceramidy metabolismus   MeSH
• elongasy mastných kyselin genetika   metabolismus   MeSH
• Gentiana chemie   MeSH
• keratinocyty cytologie   účinky léků   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• membránové proteiny genetika   metabolismus   MeSH
• metabolismus lipidů účinky léků   MeSH
• oční proteiny genetika   metabolismus   MeSH
• primární buněčná kultura MeSH
• psoriáza genetika   metabolismus   MeSH
• regulace genové exprese účinky léků   MeSH
• rostlinné extrakty chemie   farmakologie   MeSH
• sfingosin-N-acyltransferasa genetika   metabolismus   MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ceramidy MeSH
• CERS3 protein, human MeSH Prohlížeč
• elongasy mastných kyselin MeSH
• ELOVL1 protein, human MeSH Prohlížeč
• ELOVL4 protein, human MeSH Prohlížeč
• membránové proteiny MeSH
• oční proteiny MeSH
• rostlinné extrakty MeSH
• sfingosin-N-acyltransferasa MeSH

• MeSH
• extinkce (psychologie) * MeSH
• hlad MeSH
• klasické podmiňování * MeSH
• krysa rodu Rattus MeSH
• podněty * MeSH
• strach MeSH
• zvířata MeSH
• zvuk MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Ceramides (Cers) with α-hydroxylated acyl chains comprise about a third of all extractable skin Cers and are required for permeability barrier homeostasis. We have probed here the effects of Cer hydroxylation on their behavior in lipid models comprising the major SC lipids, Cer/free fatty acids (C 16-C 24)/cholesterol, and a minor component, cholesteryl sulfate. Namely, Cers with (R)-α-hydroxy lignoceroyl chains attached to sphingosine (Cer AS), dihydrosphingosine (Cer AdS), and phytosphingosine (Cer AP) were compared to their unnatural (S)-diastereomers and to Cers with non-hydroxylated lignoceroyl chains attached to sphingosine (Cer NS), dihydrosphingosine (Cer NdS), and phytosphingosine (Cer NP). By comparing several biophysical parameters (lamellar organization by X-ray diffraction, chain order, lateral packing, phase transitions, and lipid mixing by infrared spectroscopy using deuterated lipids) and the permeabilities of these models (water loss and two permeability markers), we conclude that there is no general or common consequence of Cer α-hydroxylation. Instead, we found a rich mix of effects, highly dependent on the sphingoid base chain, configuration at the α-carbon, and permeability marker used. We found that the model membranes with unnatural Cer (S)-AS have fewer orthorhombically packed lipid chains than those based on the (R)-diastereomer. In addition, physiological (R)-configuration decreases the permeability of membranes, with Cer (R)-AdS to theophylline, and increases the lipid chain order in model systems with natural Cer (R)-AP. Thus, each Cer subclass makes a distinct contribution to the structural organization and function of the skin lipid barrier.

• Klíčová slova
• biophysics, ceramides, hydroxylation, lipids, permeability, skin barrier, stratum corneum,
• MeSH
• acylace MeSH
• ceramidy chemie   MeSH
• hydroxylace MeSH
• kůže chemie   metabolismus   MeSH
• lidé MeSH
• permeabilita MeSH
• sfingosin analogy a deriváty   chemie   MeSH
• změna skupenství * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ceramidy MeSH
• phytosphingosine MeSH Prohlížeč
• safingol MeSH Prohlížeč
• sfingosin MeSH

Ceramides (Cers) are significant constituents of the stratum corneum (SC), the uppermost skin layer responsible for skin barrier properties. Cers are a heterogeneous group of lipids whose mutual interactions are still unclear. To better understand these interactions, we characterized model membranes containing stearic acid, cholesterol, cholesterol sulfate and one or more of the following ceramides: N-stearoyl-sphingosine (CerNS), N-stearoyl-phytosphingosine (CerNP) and N-(2-hydroxy)stearoyl-phytosphingosine (CerAP). Small angle X-ray scattering and FTIR spectroscopy were used to study lipid arrangement, phase separation and thermotropic behaviour. In the one-Cer systems, the membranes with CerNP showed strong hydrogen bonding and significant phase separation, even after phase transition, while the systems containing CerAP and CerNS had increased lipid miscibility. The multi-Cer systems exhibited different behaviour. In particular, the membrane containing all three Cers was a highly miscible system with narrow one-step phase transition, which, of all the studied samples, occurred at the lowest temperatures. Our results show that even a small variation in Cer structure results in substantially different phase behaviour, which is further affected by the presence of other Cer subclasses. Interestingly, the phase behaviour of the most complex three-Cer system was simpler than that of the others, highlighting the importance of lipid diversity in real SC.

• Klíčová slova
• Ceramides, FTIR, Model membranes, Skin delivery, Stratum corneum lipids, X-ray scattering,
• MeSH
• ceramidy chemie   MeSH
• hydroxylace MeSH
• kůže chemie   MeSH
• membránové lipidy chemie   MeSH
• sfingosin analogy a deriváty   chemie   MeSH
• teplota MeSH
• změna skupenství MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ceramidy MeSH
• membránové lipidy MeSH
• phytosphingosine MeSH Prohlížeč
• sfingosin MeSH

Ceramides (Cers) with ultralong (∼32-carbon) chains and ω-esterified linoleic acid, composing a subclass called omega-O-acylceramides (acylCers), are indispensable components of the skin barrier. Normal barriers typically contain acylCer concentrations of ∼10 mol%; diminished concentrations, along with altered or missing long periodicity lamellar phase (LPP), and increased permeability accompany an array of skin disorders, including atopic dermatitis, psoriasis, and ichthyoses. We developed model membranes to investigate the effects of the acylCer structure and concentration on skin lipid organization and permeability. The model membrane systems contained six to nine Cer subclasses as well as fatty acids, cholesterol, and cholesterol sulfate; acylCer content-namely, acylCers containing sphingosine (Cer EOS), dihydrosphingosine (Cer EOdS), and phytosphingosine (Cer EOP) ranged from zero to 30 mol%. Systems with normal physiologic concentrations of acylCer mixture mimicked the permeability and nanostructure of human skin lipids (with regard to LPP, chain order, and lateral packing). The models also showed that the sphingoid base in acylCer significantly affects the membrane architecture and permeability and that Cer EOP, notably, is a weaker barrier component than Cer EOS and Cer EOdS. Membranes with diminished or missing acylCers displayed some of the hallmarks of diseased skin lipid barriers (i.e., lack of LPP, less ordered lipids, less orthorhombic chain packing, and increased permeability). These results could inform the rational design of new and improved strategies for the barrier-targeted treatment of skin diseases.

• Klíčová slova
• acylceramide, ceramides, disease models, epidermis, extracellular matrix, membrane nanostructure, membranes/model, permeability, sphingolipids,
• MeSH
• ceramidy analýza   metabolismus   MeSH
• kožní nemoci metabolismus   MeSH
• kůže chemie   metabolismus   MeSH
• lidé MeSH
• membránové lipidy chemie   metabolismus   MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ceramidy MeSH
• membránové lipidy MeSH

The activity of transdermal permeation enhancers is usually evaluated in vitro on human or animal skin, but skin samples can be hard to source and highly variable. To provide a more consistent basis for evaluating the activity of permeation enhancers, we prepared relatively simple and inexpensive artificial membranes that imitate the stratum corneum (SC) lipid matrix. Our membranes were composed of stearic acid, cholesterol, cholesterol sulfate and a ceramide (CER) component consisting of N-2-hydroxystearoyl phytosphingosine (CER[AP]) and/or N-stearoyl phytosphingosine (CER[NP]). First, the permeation of theophylline (TH) and indomethacin (IND) through these membranes was compared with their permeation through porcine skin. Because the mixed CER[AP]/[NP] membrane gave the closest results to skin, this membrane was then used to test the effects of two permeation enhancers: N-dodecyl azepan-2-one (Azone) and (S)-N-acetylproline dodecyl ester (L-Pro2). Both enhancers significantly increased the flux of TH and IND through the skin and, even more markedly, through the lipid membrane, L-Pro2 having a stronger effect than Azone. Thus, our simplified model of the SC lipid membrane based on phytosphingosine CERs appears to be suitable for mimicking skin permeation.

• Klíčová slova
• Artificial model membranes, Franz diffusion cell, Permeation enhancers, Skin lipids, Transdermal absorption,
• MeSH
• aplikace kožní MeSH
• azepiny farmakologie   MeSH
• ceramidy metabolismus   MeSH
• cholesterol metabolismus   MeSH
• indomethacin farmakologie   MeSH
• kožní absorpce účinky léků   MeSH
• kůže metabolismus   MeSH
• kyseliny stearové metabolismus   MeSH
• lidé MeSH
• membránové lipidy metabolismus   MeSH
• membrány umělé MeSH
• permeabilita účinky léků   MeSH
• prasata MeSH
• theofylin farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• azepiny MeSH
• ceramidy MeSH
• cholesterol MeSH
• indomethacin MeSH
• kyseliny stearové MeSH
• laurocapram MeSH Prohlížeč
• membránové lipidy MeSH
• membrány umělé MeSH
• stearic acid MeSH Prohlížeč
• theofylin MeSH

The stratum corneum (SC) is the largest physical barrier of the human body. It protects against physical, chemical and biological damages, and avoids evaporation of water from the deepest skin layers. For its correct functioning, the homeostasis of the SC lipid matrix is fundamental. An alteration of the lipid matrix composition and in particular of its ceramide (CER) fraction can lead to the development of pathologies such as atopic dermatitis and psoriasis. Different studies showed that the direct replenishment of SC lipids on damaged skin had positive effects on the recovery of its barrier properties. In this work, cerosomes, i.e. liposomes composed of SC lipids, have been successfully prepared in order to investigate the mechanism of interaction with a model SC lipid matrix. The cerosomes contain CER[NP], D-CER[AP], stearic acid and cholesterol. In addition, hydrogenated soybean phospholipids have been added to one of the formulations leading to an increased stability at neutral pH. For the mode of action studies, monolayer models at the air-water interface and on solid support have been deployed. The results indicated that a strong interaction occurred between SC monolayers and the cerosomes. Since both systems were negatively charged, the driving force for the interaction must be based on the ability of CERs head groups to establish intermolecular hydrogen bonding networks that energetically prevailed against the electrostatic repulsion. This work proved for the first time the mode of action by which cerosomes exploit their function as skin barrier repairing agents on the SC.

• Klíčová slova
• Ceramides, Hydrogen bonding network, Langmuir monolayer, Liposomes, Skin barrier repairing agents, Stratum corneum,
• Publikační typ
• časopisecké články MeSH