Unravel fibroblast-epithelial crosstalk supporting keratinocytes self-renewal to improve skin graft production

Grantee: Mariaceleste Aragona, Associate Professor, Novo Nordisk Foundation Centre for Stem Cell Medicine

Amount: DKK 3,999,975

Grant category: Research Grants in open competition

Year: 2023

Geography: Denmark

In this project Mariaceleste Aragona, in collaboration with Elena Enzo (University of Modena and Reggio Emilia, Italy), aims at the optimization of skin graft production for regenerative and replacement purpose.

Skin grafts for transplantation purposes are generated from epidermal stem cells. These regenerative therapies are life-saving procedures and have been demonstrated to be successful and safe for the treatment of burns and severe genetic diseases. Long lasting skin regeneration requires the correct amount of stem cells (SCs) in the graft. However, the treatment of large burns or skin replacement therapy in elderly patients are still challenging.

In such situations, the limited area of donor sites, and the physiological reduction of the number of SCs results in insufficient availability of SCs for graft production. A way to efficiently produce more SCs is to enforce their self-renewing – the process of generating more SCs – capacity.

A condition that forces SCs to increase their self-renewal capacity is tissue stretching. In this project, Mariaceleste Aragona aims to generate a comprehensive atlas of the changes occurring in space and time during tissue stretching. Based on this atlas, they will elucidate the signaling molecules instructing SC’s self-renewal and identify options to target such molecules. This knowledge will be used to develop cell culture conditions to ameliorate skin graft productions for clinical application.

Collectively, such insights will provide new fundamental knowledge on the biology of SCs and this approach may improve the clinical success of skin regenerative and replacement therapies to the benefit of patients.

Dysregulated immune homeostasis through altered glycans in inflammatory skin diseases

Grantee: Hans Wandall, Professor, MD, PhD, University of Copenhagen

Amount: DKK 3,187,800

Grant category: Research Grants in open competition

Year: 2023

Geography: Denmark

Hans Wandall’s project aims to investigate the potential role of sugar molecules (glycans) in inflammatory skin diseases.

Several skin diseases, including atopic dermatitis, contact dermatitis, and psoriasis, are caused by a cascade of inflammatory events localized to the epidermis and the dermis.

Based on substantial preliminary findings showing dysregulation of glycosylation (sugarcoating) of the cells in the skin of patients with inflammatory skin diseases, Hans Wandall and his team hypothesize that carbohydrate receptors on immune cells recognize inflammation-induced glycan changes and induce a vicious cycle that aggravates inflammatory skin diseases in susceptible individuals.

They will investigate this through a three-pronged approach: 1) characterize the glycosylation patterns of skin samples obtained from patients diagnosed with contact dermatitis, psoriasis, and atopic dermatitis, and also analyze glycosylation patterns on human keratinocytes and fibroblasts from skin-inflammation models based on human 3D organ-like skin systems with exogenous cytokines and inflammatory cells and samples from murine models of inflammatory skin diseases. 2) Next, they will co-culture immune cells with keratinocytes ablated for select glycosylation pathways to define the functional role these in relation to glycan changes, and finally, 3) analyze the importance of key immune receptors sensing the glycan changes.

Through the investigations, the project will systematically evaluate the role of glycans in inflammatory skin diseases with a promise to provide new targets for interventions.

Regulatory Function of Dermal Adipocytes in Skin and Systemic Energy Homeostasis

Grantee: Nils Færgeman, Professor, University of Southern Denmark

Amount: DKK 2,336,250

Grant category: Research Grants in open competition

Year: 2022

Geography: Denmark

Nils Færgeman’s proposal investigates the role of acyl-CoA binding protein (ACBP) in regulating dermal white adipose tissue function in the skin.

Dermal white adipose tissue (dWAT) is a distinct type of fat depot located under the reticular dermis (the deepest layer of the dermis) and comprises a special layer of the skin. Compared to other well-defined fat depots, dWAT shows a very high degree of plasticity, and can rapidly and locally expand and reduce its volume in response to various stimuli.

Via lipolysis (an enzymatic process that releases free fatty acids from triglycerides in fat depots) dermal white adipocytes (fat cells) release fatty acids into the extracellular space, which for example can regulate production of extracellular matrix in dermal fibroblasts and differentiation of keratinocytes.

Recently, Nils and colleagues have demonstrated that acyl-CoA binding protein plays a fundamental role in lipid metabolism in the skin and is indispensable for its barrier function. Given that ACBP is required for differentiation of white adipocytes and given its high expression in the skin, the hypothesis behind this project is that ACBP plays a critical role in dermal adipose tissue by serving as a key regulator and driver of intracellular fatty acid metabolism.

The group will use state-of-the-art lipidomics (global analyses of lipid composition and abundance) and genomics technologies and a series of novel mouse models, to clarify the role of ACBP in dWAT functions in the skin and to define the role of dWAT in systemic energy metabolism.

Treatment of ichthyosis with enzyme replacement therapy

Grantee: Lotte K. Vogel , Associate Professor, University of Copenhagen

Amount: DKK 3,000,900

Grant category: Research Grants in open competition

Year: 2022

Geography: Denmark

This project led by Lotte K. Vogel aims to elucidate the role of the protease matriptase (an enzyme that cleaves proteins) in a variant of Ichthyosis, a common skin disease that causes “fish-scale” like skin with poor treatment options.

The molecular mechanisms behind ichthyosis are not understood, but variations in several genes may cause ichthyosis. Variants of the ST14 gene, which encodes the serine protease matriptase, lead to a type of ichthyosis called Autosomal Recessive Congenital Ichthyosis 11 (ARCI11). The prevalence of ARCI11 is elusive at present.

Lotte and her team’s preliminary data show that ARCI11-related matriptase variants are unable to activate a certain substrate (a protease on its own), suggesting that ARCI11 is caused by a lack of activation of this protease. Results from the group also suggest that inactivation of a certain enzyme cascade leads to Ichthyosis. Surprisingly, for several enzymes in this cascade both the zymogen form and the activated form of the enzyme exhibit proteolytic activity.

In this project, Lotte aims to investigate the importance of matriptase in ARCI11 through a three-pronged approach: (1) by elucidating whether a protease located downstream of matriptase in the same pathway can be activated by an appropriate soluble enzyme which is suitable for topical application to the skin. (2) by elucidating whether ARCI11 is caused by a difference in substrate preferences between the zymogen form and the activated form of these enzymes and (3) by systematically screening for genetic variants of matriptase causing ARCI11 and estimating their frequency in the population. The genetic material to do a more systematic search for ARCI11-causing variants of matriptase and estimate their frequency Is already available.

If successful, Lotte’s project will make a solid and original contribution to the understanding of ichthyosis that may lead to improved treatment options.

Structure and modulation of the integrin receptor αMβ2 in relation to SLE

Grantee: Gregers Andersen, Professor, Aarhus University

Amount: DKK 1,713,040

Grant category: Research Grants in open competition

Year: 2022

Geography: Denmark

Gregers Andersen’s project aims to understand the role of disease-related mutations of a central inflammation-regulating protein on immune cells in systemic lupus erythematosus (SLE).

Systemic lupus erythematosus is a severe autoimmune disease in which our immune system is erroneously activated. This leads to inflammation that may destroy tissue, such as the kidney. SLE often manifests itself with visible skin rashes that are difficult to treat and debilitating for the patient. Current options for treatment of SLE are insufficient and still rely heavily on steroids as the mainstay of treatment.

Both environmental and genetic factors contribute to SLE pathogenesis. The strongest association between SLE and the information encoded in our genetic material is observed for a specific mutation in a gene called ITGAM. This gene codes for a protein called αMβ2 located at the surface of our immune cells. When the αMβ2 protein recognizes specific proteins on other cells, the immune cell contributes to dampening inflammation. When the ITGAM gene is mutated, the immune cells are less efficient in suppressing inflammation.

Using the most powerful microscope available, Gregers’ research project will investigate in atomic detail how the mutation interferes with the normal function of the αMβ2 protein. Furthermore, the effects of a new antibody capable of increasing the activity of αMβ2 will be exhaustively investigated. Experiments comparing the effects of this antibody on immune cells from healthy and SLE individuals will be central in deciding whether the antibody is a candidate for a new type of therapeutic agent.

Deliniating the functional role of ERAP2 and HLA-C in the pathogenesis of psoriasis

Grantee: Claus Johansen, Associate Professor, Aarhus University

Amount: DKK 3,230,325

Grant category: Research Grants in open competition

Year: 2022

Geography: Denmark

Claus Johansen’s project investigates the role of the protein ERAP2 in the pathogenesis of psoriasis.

Psoriasis is considered an autoimmune disease – i.e., a disease in which the T-cells of the immune system attack and destroy the body’s own cells by error. During an exposure to external factors (peptides, bacteria etc) a system of specialized cells engulfs, digests, and presents peptide fragments (antigens) of these external factors on their surface to the body’s immune cells – usually cytotoxic CD8+ T-cells – which, once activated, then surveil, identify, and destroy foreign elements containing that specific peptide or peptides with very similar overall structure. The peptides are presented by a specific receptor, called the human leukocyte antigen (HLA) receptor and it is well-known that a particular subtype of this receptor, the HLA-C receptor is dominant in psoriatic patients – still, concrete disease-specific self-antigens have not yet been identified. Recent results have indicated that a protein, ERAP2, which facilitates the association of antigen peptides to HLA receptors may have a role to play in the erroneous recognition of self-antigens in autoimmune diseases like psoriasis. Claus and his team aim to clarify the role of this protein in the current proposal.

If successful, their project may help shed further light on the autoimmune characteristics of psoriasis – and eventually help guide new treatment approaches.

Control of cutaneous immune responses by T follicular regulatory cells in systemic autoimmunity

Grantee: Søren Degn, Associate Professor, Aarhus University

Amount: DKK 2,795,064

Grant category: Research Grants in open competition

Year: 2022

Geography: Denmark

This project, led by Søren Degn, aims to investigate the role of a newly discovered immune cell, the T follicular regulatory cell (Tfr), in controlling systemic autoimmunity.

Søren Degn and his team have discovered that Tfrs are able to maintain tolerance in the skin even in the face of systemic inflammation, which in that case appear to be reversible, but also that if Tfr control in the skin fails, the systemic inflammation becomes irreversible and chronic.

Using a mouse model where Tfrs are selectively deleted, Søren and his team will investigate immune responses and identify which specific self-antigens are targeted when the tolerance maintained by the Tfrs is lost.

Chemical compounds that impede the pathogenic effects of Staphylococcus aureus in atopic dermatitis

Grantee: Tim Tolker-Nielsen, Professor, University of Copenhagen

Amount: DKK 3,236,161

Grant category: Research Grants in open competition

Year: 2022

Geography: Denmark

The project by Tim Tolker-Nielsen aims to identify novel chemical compounds as potential drug leads for treating bacterial involvement in atopic dermatitis. The present project builds on findings from another LEO Foundation grant, which discovered a central factor, Sbi, responsible for the virulence (the ability to cause disease) of the bacteria Staphylococcus aureus in atopic dermatitis flares. As this factor appears to be unique to that bacterium it can be targeted with minimal impact expected on beneficial commensal (i.e. non-pathogenic) bacteria. Tim and his team will utilize existing libraries of chemical compounds to screen for lead candidates that can prevent the production of Sbi and which may be developed into a future treatment for atopic dermatitis flares.

Auto-inducing peptides (AIPs) for treatment of skin infections caused by staphylococci

Grantee: Christian Olsen, Professor, University of Copenhagen

Amount: DKK 2,990,405

Grant category: Research Grants in open competition

Year: 2021

Geography: Denmark

The research project by Professor Christian Olsen pursues a cutting-edge strategy for the treatment of skin infections.

Staphylococcal bacteria are the most common cause of skin and soft tissue infections, and with the rise of methicillin-resistant Staphylococcus aureus (MRSA), this new strategy could – if successful – help prevent minor infections from becoming severe medical conditions. Furthermore, the strategy could minimize the risk of emerging antibiotic resistance.

Bacteria produce and release molecules known as ‘virulence factors’ which cause damage. The production of these harmful molecules is regulated through a form of cell-to-cell communication called ‘quorum sensing’, where the concentration of virulence factors increases as a function of cell density. The present project aims to weaken the severity of bacterial skin infections by inhibiting ‘quorum sensing’ with synthetic auto-inducing peptide (AIP) analogs, and as a result, decrease the excretion of virulence factors.

‘Quorum sensing’ inhibition will target the severity of the bacterial infection, rather than the viability of the individual bacterium and represents an alternative to antibiotics, as there is no evolutionary pressure on the individual bacterium to develop towards a state that is not affected by these compounds. Therefore, minimal risk of emerging antibiotic resistance is to be expected from this strategy.

PACT: Personalizing Acne Treatment Using Skin Microbiota Transplantation

Grantee: Holger Brüggemann, Associate Professor, Aarhus University

Amount: DKK 2,179,800

Grant category: Research Grants in open competition

Year: 2021

Geography: Denmark

This project aims to investigate the potential of using bacteria exchange or “microbiome transplant” as a viable treatment option for acne vulgaris.    

Acne vulgaris remains one of the most prevalent skin conditions worldwide affecting close to 10% of the population and impacting the quality of life of millions of people. Multiple factors contribute to acne, including genetics, excess sebum production, colonization of the skin by Cutibacterium acnes and an inflammatory cascade. Current treatments for acne such as retinoids and antibiotics have varied outcomes and side effects. As antibiotic resistance becomes an increasing concern in clinical practice, there is an unmet need for alternative treatment approaches.   

The team have previously identified a range of bacterial strains, isolated from healthy skin, that can selectively inhibit acne-associated Cutibacterium acnes strains. The current project takes a microbiome transplantation approach to acne treatment, utilizing a pre-existing in-house library of more than 1000 bacterial strains and testing their ability to modulate the skin microbiome and reduce acne symptoms in patients with mild-to-moderate acne.  

This project may pave the way for developing a personalized treatment to a very common skin disease while avoiding the issue of antibiotic resistance.