The stratum corneum (SC) plays a fundamental role in the barrier function of the skin. The SC consists of corneocytes embedded in a lipid matrix.

Source: International Journal of Cosmetic Science, Volume 37, Number 1, pp. 158-158 (2015) ISBN: 0142-5463

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…

The lipid matrix of the skin's stratum corneum plays a key role in the barrier function, which protects the body from desiccation. The lipids that make up this matrix consist of ceramides, cholesterol, and free fatty acids, and can form two coexisting crystalline lamellar phases: the long periodicity…

An important feature of atopic eczema (AE) is a decreased skin barrier function. The stratum corneum (SC) lipids - comprised of ceramides (CERs), free fatty acids (FFAs) and cholesterol - fulfill a predominant role in the skin barrier function.

In order to gain a better insight into the basis of the rapid jasmonic acid (JA)-mediated stress response, an integrated approach using a targeted high-resolution mass spectrometry-based (HRMS) platform, was conducted to monitor the metabolism of JA using the model system of cell suspension cultures…

Our in-house human skin equivalents contain all stratum corneum (SC) barrier lipid classes, but have a reduced level of free fatty acids (FAs), of which a part is mono-unsaturated. These differences lead to an altered SC lipid organization and thereby a reduced barrier function compared to human skin.…

The stratum corneum is the outermost skin layer and consists of dead cells embedded in a lipid matrix.

Synthesis and application of chemical biology tools to study immunomodulatory signaling lipids.

The research described in this thesis shows that hypercholesterolemia, a well-established risk factor for atherosclerosis, can impact skin lipid pool and barrier function already at young age. In the field of atherosclerosis, we showed that the small peptide Lyp-1 can be used as a targeting molecule…

Structure-affinity relationship (SAR) and structure-kinetics relationship (SKR) studies were combined to investigate a series of biphenyl anthranilic acid agonists for the HCA2 receptor.

Barrier function is the natural role of the skin. The lipid matrix present in the outermost layer of the skin, the stratum corneum is important for this function.

Evolution acts via mutations in amino acid sequences. Substitution of essential amino acids leads to a nonfunctional protein. l.

We are developing biology-driven platforms to measure metabolites based on liquid chromatography-mass spectrometry (LC-MS), gas chromatography-MS (GC-MS), and capillary electrophoresis-MS (CE-MS).

The BioMedical Metabolomics Facility Leiden (BMFL) offers a highly structured environment for advanced metabolomics studies. BMFL builds on fully validated, state-of-the-art platforms that each cover a part of the human metabolism and together span the complete human metabolome.

Antibiotic resistance, caused by widespread use of antibiotics, leads to bacterial infections that are difficult, if not impossible, to treat and is a major worldwide health concern.

Promotor: G.A. van der Marel, Co-promotor: J.D.C. Codée

Lipid signaling is an essential biological event/process in a plethora of pathophysiological conditions. The underlying idea of this thesis is that many of the roles and the complex interplay of the individual signaling lipids in inflammatory processes and related conditions in health and disease is…

PhD defence

Salicylic acid (SA) is a plant hormone, which is involved in the defense responses to pathogens and to abiotic stress, and in the regulation of plant growth and development.

There is considerable need for improved skin models to develop safe and efficient drugs for skin delivery as well as for cosmetic and chemical product testing on the skin.

How are the epidermal lipid pathways involved in health and disease.

The drug BIA 10-2474 inhibits fatty acid amide hydrolase (FAAH), a lipase that degrades a specific endocannabinoid. On the basis of this activity, BIA 10-2474 was being developed as a potential treatment for anxiety and pain. In a phase 1 trial of the drug, one subject died, and four others suffered…

It is the aim of this project to better understand how the physical properties of lipids influences the structure and overall barrier function of the skin.

The lipid matrix in the stratum corneum (SC), the upper layer of the skin, plays a critical role in the skin barrier. The matrix consists of ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs).

N-acylethanolamines (NAEs), which include the endocannabinoid anandamide, represent an important family of signaling lipids in the brain. The lack of chemical probes that modulate NAE biosynthesis in living systems hamper the understanding of the biological role of these lipids.

Key publications of the Skin Barrier and Vaccination group.

This thesis presents the first synthetic peptides ADP-ribosylated on serine, threonine, tyrosine, arginine and cysteine.

Netherton Syndrome (NTS) is a rare genetic skin disease caused by mutations in the serine protease inhibitor Kazal-type 5 gene, which encodes the lympho-epithelial Kazal-type-related inhibitor. NTS patients have a profound impaired skin barrier function. Because SC lipids play a crucial role in the…

The skin barrier function is provided by the stratum corneum (SC). The lipids in the SC are composed of three lipid classes: ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs) which form two crystalline lamellar structures. In the present study, we investigate the effect of CER chain length…

Ceramides (CERs), cholesterol, and free fatty acids (FFAs) are the main lipid classes in human stratum corneum (SC, outermost skin layer), but no studies report on the detailed analysis of these classes in a single platform.

Promotores: Prof.dr. C.A.M.J.J. van den Hondel, Prof.dr. V. Meyer (Technische Universität Berlin)

The outermost layer of the skin, the stratum corneum (SC), is responsible for the skin barrier function, protecting the body from pathogens, chemicals and other unwanted substances from the external environment. The SC lipid matrix provides the only continuous pathway through the SC and is considered…

Promotors: Prof.dr. E. Bouwman, Prof.dr. E. Drent

Pharmacologist Walter Boiten developed a new method to determine the amount of lipids in a person's skin. With this method he tested the effects of a new cream he developed for eczema patients. The first results are promising. Boiten defends his dissertation on 15 January.

BACKGROUND: Explant human skin equivalents (Ex-HSEs) can be generated by placing a 4mm skin biopsy onto a dermal equivalent. The keratinocytes migrate from the biopsy onto the dermal equivalent, differentiate and form the epidermis of 1(st) generation Ex-HSEs. This is especially suitable for the expansion…

Current research at the Skin Barrier and Vaccination group.

Tineke Berkers has won an award for outstanding contribution for her poster at the Gordon Research Conference at Waterville Valley, USA.

People with relatively high levels of lipids in their blood are less likely to develop allergic conditions such as eczema and asthma. These lipids cause genes that play a key role in allergic reactions to be less active. Researchers from the Leiden University Medical Center (LUMC) have published an…

Specific fatty acid-sugar molecules allow leprosy bacteria, among others, to hide from our immune system. How exactly is not entirely clear. Hessel van Dijk, who received his PhD on 13 October, replicated the molecules, helping to solve a piece of the puzzle. Van Dijk's dissertation is titled: Synthesis…

This thesis describes the use of bioorthogonal proteins in immunological settings. It provides an introduction towards the field of protein modification, which was used throughout the thesis for the expression of proteins containing unnatural amino acids.

Promotor: M.T.M. Koper, Co-Promotor: L.B.F. Juurlink

Promotor: A.P. IJzerman

BlaC is the β-lactamase of Mycobacterium tuberculosis. We show that it can recover from inhibition by clavulanic acid and that phosphate helps it do so.

The soil ecosystem consists of the largest reservoir of biodiversity on Earth.

An interdisciplinary photo exhibition about crafts and craftsmanship in different cultures will open at Oude UB on 6 October. At the opening Fridus Steijlen will give an introduction to the Tau Tau puppets that are made in Sulawesi, Indonesia.

Activity-based protein profiling (ABPP, also termed chemical proteomics), is one of the pillars of chemical biology, and at LED3 we have taken it to the next level. ABPP allows the assessment of protein function in live cells and tissues, which means that the activity of a complete protein family can…