Digging deep for filaggrin’s function in regulating epidermal barrier formation

Grantee: Ellen van den Bogaard, Professor, Radboud University Medical Center

Amount: DKK 3,929,813

Grant category: Research grants in open competition

Year: 2022

Geography: Netherlands

The aim of Ellen’s project is to improve the understanding of the role of skin protein filaggrin (FLG) in regulating and controlling epidermal keratinocyte robustness and differentiation.

Ever since the discovery that loss-of-function mutations in the FLG gene are the main risk factor for developing Atopic Dermatitis (AD), many studies have aimed to relate the presence or absence of FLG to processes involved in skin homeostasis. The filaggrin protein is comprised of several repetitive elements as well as two unique domains, A and B. While many mutations in the filaggrin monomers are known to be important in AD, the role of the A and B domains have been less studied.

Previous investigation, featuring collaborator and postdoctoral fellow Jos P.H. Smits, discovered that mutations in these domains affect the expression of genes that are important for terminal differentiation of epidermal keratinocytes. The terminal differentiation of keratinocytes is important for the formation of the skin barrier. In this project, the team want to expand initial findings into elaborate studies using 3D skin organoids, also called “human skin equivalents” combined with in-depth molecular and functional analyses. Ellen’s group has developed many of these 3D skin equivalents to resemble both the structure and environment of real skin. By exposing the skin equivalents to relevant environmental factors, they will study how mutations in the filaggrin A and B domains affect keratinocyte differentiation and terminal fate and ultimately the overall skin barrier function. The hope is to identify potential new targets for therapeutic interventions in AD by modifying the expression of filaggrin and thereby regulating the barrier function of the skin.

Psoriasis: a microbiome-driven disease?

Grantee: Patrick Zeeuwen, Radboud University Medical Center, Nijmegen

Amount: DKK 2,545,944

Grant category: Research grants in open competition

Year: 2018

Geography: Netherlands

Psoriasis is highly prevalent and has a significant medical and socio-economic impact.

The prevailing dogma has been that abnormalities of the adaptive immune system were primary, but genetic studies have highlighted the importance of local skin-specific factors. We and others have identified epidermis-specific innate immunity genes, like beta-defensins and Late Cornified Envelope (LCE) genes, to be associated with disease development.

We recently made two exciting observations. First, deletion of LCE3B and LCE3C does not merely imply the loss of two genes but has a genomic effect that leads to a strong induction of the flanking LCE3A gene. Secondly, we found that LCE proteins, and LCE3A in particular, have broad-spectrum antimicrobial activity. We hypothesize that the LCE3B/C-del status affects the cutaneous host defense repertoire thereby shaping the skin microbiome. We aim to investigate the biology of LCE genes and to translate these findings to our understanding of psoriasis pathogenesis.

Key objectives are to:

  1. assess the antimicrobial activity and specificity of all LCEs and their synergy with other antimicrobial proteins. This will be investigated by metagenomic approaches and classical in vitro microbiological assays, using recombinant and synthetic LCE proteins and peptides derived thereof
  2. investigate LCE3B/C-del in isogenic 3D-skin equivalents in vitro generated from the immortalized human keratinocyte N/TERT cell line. Deletions of other LCE genes or their regulatory sequences will be made using CRISPR/Cas9 technology. Effects on epidermal biology relevant to psoriasis will be studied and include antimicrobial host defense, innate immune response and skin barrier function

Skin barrier dysfunction and thymus size during the first year of life as predictors for atopic dermatitis

Grantee: Jacob P. Thyssen MD PhD DmSci, Trine Danvad Nilausen MD, Lone Skov MD PhD DmSci, Dep. Dermatology and Allergology, Herlev-Gentofte Hospital, Hellerup, Denmark, Caroline Ewertsen MD PhD, Department of Radiology, Rigshospitalet, Copenhagen, Denmark, Charlotte Bonefeld PhD, Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, Pal Szecsi MD DmSci, Department of Clinical Biochemistry, Herlev-Gentofte Hospital, Hellerup , Denmark, Sanja Kezic PhD, Coronel Institute, AMC, University of Amsterdam, The Netherlands, and Christoph Riethmüller PhD, nAnostic Institute, Centre for Nanotechnology, University of Münster, Germany

Amount: DKK 2,558,500

Grant category: Research grants in open competition

Year: 2016

Geography: Denmark, Germany, Netherlands

The study is foreseen to increase the understanding of the skin barrier and immune system in atopic dermatitis.

Through international collaboration with scientists who perform state of the art and pioneering analyses on skin samples as well as national collaboration with immunologists and radiologists, the team will seek to evaluate non-invasive and easily collectable biomarkers that can predict the risk for atopic dermatitis.

The study has the potential to provide insight in atopic dermatitis pathogenesis and the value of promising pre-atopic dermatitis biomarkers that indicate both inflammation and skin barrier barriers dysfunction. This could be used to develop an algorithm that can better predict the onset of atopic dermatitis.

The team’s work may thus substantially increase the understanding of skin biology in neonates, both normal and diseased. The study will also provide a basis for not only future large-scale observational studies, but also randomised controlled studies evaluating the efficacy of preventive skin barrier restoration or anti-inflammatory treatment in selected groups, potentially reducing the incidence and complications of the most common skin disease in childhood.

Depletion, UV Exposure and Relation between Ozone and Skin Cancer

Grantee: Dr. Harry Slaper, Laboratory for Radiation Research, RIVM, Holland

Amount: DKK 200,000

Grant category: Research grants in open competition

Year: 2012

Geography: Netherlands

Dr. Harry Slaper, Laboratory for Radiation Research, RIVM, Holland, has developed a unique model, the AMOUR 2.0, for relating ozone depletion scenarios and UV to changes in skin cancer incidence (melanoma, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)). This model has been used since 2008 as a reference for other researchers in Europe.

The model, however, does not factor in age. Apart from cumulated UV Radiation, age is the major risk factor for the development of Non Melanoma Skin Cancer (NMSC), and an ageing population will contribute to the increasing incidence of NMSCs.

The LEO Foundation has funded a development of the model to also incorporate the effects of population aging in Europe in order to obtain a more precise picture of the projected incidence of NMSC in Europe.

Based on the Dutch Cancer registry and the enhanced model, then, Dr. Slaper has estimated age and gender specific incidence rates, incorporated them into the model as well as UN Population forecasts to forecast the incidence of NMSC in Europe and the contribution of both cumulated UV radiation and age and gender.

The results are expected to play a key role in raising awareness among decision makers in the health care sector on the increasing incidences of non-melanoma skin cancer, an awareness which will also benefit patients as the long-term aim is to increase the political prioritisation of non-melanoma skin cancer.