The LEO Foundation Award 2019 – Region Americas

Grantee: Maksim Plikus

Amount: USD 100,000

Grant category: LEO Foundation Awards

Year: 2019

Geography: USA

Maksim Plikus is Associate Professor at the Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, USA

He receives 100,000 USD for his research in skin stem cells and regeneration.

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SID Resident Retreat for Future Academicians

Grantee: Society for Investigative Dermatology

Amount: EUR 15,000

Grant category: Education and awareness grants

Year: 2019

Geography: USA

The SID mission is to advance the sciences relevant to skin disease through education, advocacy and scholarly exchange of scientific information.

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Elucidating the origins of melanoma

Grantee: A. Hunter Shain

Amount: DKK 2,500,000

Grant category: Research grants in open competition

Year: 2019

Geography: USA

The overarching goal of this grant is to better understand the origins of melanomas that appear suddenly, or de novo.

Approximately 70% of melanomas appear in this way, while the remainder grow out of preexisting nevi. Nevi can be monitored and prophylactically removed if they show signs of change, but melanomas that arise de novo are impossible to foresee. It is therefore of utmost importance to understand the origins of melanomas that appear de novo in order to develop biomarkers to predict their emergence.

We previously sequenced melanomas adjacent to nevi, revealing two classes of mutations – initiating mutations (emerging in nevi) and progression mutations (emerging in melanoma). Here, we hypothesize that progression mutations can precede initiating mutations. In this scenario, a melanocyte silently accumulates progression-associated mutations, followed by an initiating mutation so that the ensuing neoplasm ‘skips’ the precursor stages, manifesting directly as a melanoma.

If validated, this hypothesis would explain how de novo melanomas evolve. Here, we will genotype individual melanocytes from healthy human skin to test whether morphologically normal melanocytes can harbour progression mutations. Towards this goal, we have developed innovative solutions to establish high-quality genotyping calls from individual cells. In our preliminary data, we genotyped 17 melanocytes collected from healthy skin, and pathogenic mutations were surprisingly common, supporting our hypothesis. We will extend these studies to fully delineate the spectrum of cancer-associated mutations in melanocytes from healthy skin.

Overall, completion of these studies will reveal the origins of melanomas that do not pass through a precursor stage – a longstanding goal in the skin research community.

A multi-pronged approach to decipher the role of melanosomal transporters in human pigmentation

Grantee: David M Sabatini, Professor of Biology, Whitehead Institute of Biomedical Research

Amount: DKK 2,666,588

Grant category: Research grants in open competition

Year: 2019

Geography: USA

Dozens of genes are known to be involved in human pigmentation. Many of these genes encode proteins with well-understood functions, such as in melanocyte development, melanin biosynthesis, and the biogenesis and trafficking of specialized melanin-containing organelles called melanosomes.

Yet, we do not know the molecular function of a class of pigmentation genes encoding putative transport proteins that localize to the melanosome. Identifying their substrates would represent a significant advance in our understanding of how melanin synthesis is regulated and how variants in these genes result in differences in human pigmentation.

Based on a method we developed to rapidly and specifically isolate melanosomes, termed MelanoIP, we can capture melanosomes in minute time-scales such that their labile metabolic contents are preserved for quantitative analysis.

Using this technology, we have performed a comparative study of melanosomal metabolites from cells with several pigment genes disrupted, including the putative melanosomal transporter encoding genes Slc45a2, Oca2, and Mfsd12, which has revealed potential substrates. In this proposal, we will define the substrates of these transporters using MelanoIP, metabolite profiling, and organellar uptake screens.

We will also perform follow-up biochemical analysis of each transporter and its naturally occurring genetic variants. Our unique combination of rigorous approaches will inform our understanding of how melanosomal transporters regulate melanin synthesis, and uncover the molecular basis of how mutations in these melanosomaltransport genes lead to human pigment variation.

Knowledge gained from this study will inform the development of interventions for modulating pigmentation and treating pigmentation pathologies.

Role of Skin Stem Cells in Psoriasis and Atopic Dermatitis

Grantee: George Murphy, Professor, Brigham & Women’s Hospital, Boston

Amount: DKK 3,988,427

Grant category: Research grants in open competition

Year: 2019

Geography: USA

This two-year proposal is based on the hypothesis that skin stem cells are critically involved in the pathogenesis of psoriasis and atopic dermatitis.

In previous work, the three principal investigators have identified a cytokeratin 15-expressing stem cell niche at the tips of epidermal rete ridges, discovered immunomodulatory dermal mesenchymal stem cells, and defined an epigenetic mark that regulates skin stem cell behavior.

During the past year that was funded by the LEO Foundation, we have provided data that supports epidermal stem cell participation in human and experimental psoriasis and begun to probe the genetic and epigenetic underpinnings of this phenomenon.

We now propose to advance these findings to determine mechanistic commonalities in stem cell behavior that may unify the pathogenesis of psoriasis and atopic dermatitis. Specifically, the proposal focuses on epidermal and dermal stem cells in the context of innovative experimental models, human biospecimens to test relevance, and epigenetic modifiers that may be transformative in normalizing stem cell aberrations responsible for the initiation and propagation of these two prevalent, pernicious, and potentially preventable skin diseases.

The LEO Foundation Award 2018 – Silver Award

Grantee: Dr. Tiffany Scharschmidt

Amount: DKK 500,000

Grant category: LEO Foundation Awards

Year: 2018

Geography: USA

The Silver Award went to Dr. Tiffany Scharschmidt from University of California San Francisco, USA, for her work on the skin microbiome and its interplay with the adaptie immune system.

Have a sneak peek into her research Video about Dr. Tiffany Scharschmidt

Fully Synthetic Lincosamides to Combat Multidrug-Resistant Skin Infections

Grantee: Prof. Dr. Andrew G. Myers, Amory Houghton Professor of Chemistry Harvard University, Cambridge, MA

Amount: DKK 3,108,110

Grant category: Research grants in open competition

Year: 2018

Geography: USA

Many common skin infections are caused by the Gram-positive bacterial species Staphylococcus aureus and Streptococcus pyogenes. The infections lead to conditions ranging in severity from minor folliculitis to life threatening skin reactions. If not managed successfully, they may escalate into lethal systemic infections.

Commonly, these diseases are treated with clindamycin, a prototypical member of the wide-ranging so-called lincosamide antibiotic class. Its clinical importance is underlined by the World Health Organization’s listing of it as an essential medicine. In the past decades, however, prevalence of in particular lincosamide resistant Staphylococci and Streptococci has risen sharply. The rise threatens to diminish clindamycin’s usability in the future, even render it obsolete.

In the course of this project, the team led by Andrew G. Myers of Havard University, will seek to address this growing unmet medical need by synthetic discovery efforts focused on the lincosamide class.

The team’s preliminary results indicate that new lincosamides uncovered in this fashion are able to address the contemporary resistance threats: Many of the compounds designed, synthesised, and evaluated by the team to date have shown themselves active against multidrug-resistant clinical isolates of Staphylococci and Streptococci, and at the same time they demonstrate favourable pharmacokinetic and safety profiles.

The team expects that it can uncover new candidates displaying expanded spectra of action against MDR and Gram-negative bacteria. The expected results can then be used to advance refined lead candidates capable of demonstrating efficacy in in vivo murine models of skin infection, and thus yield substantial promise for further clinical development of actual treatments.

 

Project group

Dr. Amarnath Pisipati, Postdoctoral microbiologist

Matthew J. Mitcheltree, PhD student, chemistry

Ioana Moga, PhD student, chemistry

Katherine J. Silvestre, PhD student, chemistry

 

International affiliation

The Institut Pasteur, Annecy, France – International Course on Antibiotics and Resistance (ICARe), Organizing Committee, Core Faculty

In vivo model of human melanoma using a novel crest chimera system

Grantee: Dr. Rudolf Jaenisch, Member, Whitehead Institute and Professor, Department of Biology, Massachusetts Institute of Technology, MA

Amount: DKK 2,476,836

Grant category: Research grants in open competition

Year: 2018

Geography: USA

Two major challenges when using mouse models to model human cancers such as melanoma are that the human tumor cells transplanted to mice 1) represent the end-stage of the disease and 2) that the host animals are usually immunocompromised.

Thus, these models fail to actually show development of the disease and they fail to display the ongoing interaction between melanoma cells and the immune system as the disease progresses.

To curb these two shortcomings, the team led by Rudolf Jaenisch of Massachusetts Institute of Technology, has set out to create an experimental model system that will make it possible to study initiation, progression, and manifestation of human melanoma in immune competent host animals.

Their basis is generation of human-mouse neural crest chimeras – where mice embryos are introduced with human neural crest cells carrying the genetic dispositions alleged to lead to development of the particular cancer – and their goal is a model that has the potential to show how melanoma cells evade the immune system.

Given a positive outcome, this innovative project can help devise strategies to improve the effectiveness of current immunotherapies, to test novel immunotherapies, and to identify novel targets in melanoma treatment.

 

Project group

Malkiel Cohen, Postdoctoral researcher

Kristin Andrykovich, Graduate Assistant

Probing the function of melanosomal transporters in pigmentation using metabolic profiling

Grantee: David M. Sabatini, Whitehead Institute of Biomedical Research

Amount: DKK 1,278,270

Grant category: Research grants in open competition

Year: 2018

Geography: USA

Studies in human populations have identified dozens of pigmentation genes, many of which encode proteins with well-understood functions, such as in melanocyte development, melanin biosynthesis, and the biogenesis and trafficking of specialized melanin-containing organelles called melanosomes.

Yet, there are other pigmentation genes that we know much less about, such as those that encode putative transporter proteins on the melanosome surface. These putative melanosomal transporters have been reported to import precursor metabolites for melanin synthesis or regulate melanosomal pH; however, many of these findings have been controversial or speculative. Deciphering the molecular function of these putative transporters and their physiological substrates is crucial to our understanding of pigmentation.

To address this problem, we propose to determine the metabolite composition of melanosomes and define the role of individual transporters in melanosomal function. We will develop a purification method to rapidly isolate intact melanosomes and analyse them by liquid chromatography and mass spectrometry to compile the first catalog of melanosomal metabolites. We will subsequently characterize SLC45A2, a putative melanosomal transporter that modulates human pigmentation in response to sunlight. By comparing the metabolite profile of wild-type versus SLC45A2-deficient melanosomes, we will identify candidate SLC45A2 substrates and validate them using biochemical assays, a workflow that will be applied to other putative melanosomal transporters.

This study will present the first detailed analysis of melanosome metabolites, as well as identify key metabolites and their transporters essential for melanogenesis. This work could inform new ways to modulate pigmentation and treat pigmentation pathologies.

Nucleic Acid Ionic Liquids (NAILs) for Topical Skin Applications

Grantee: Samir Mitragotri, Harvard John A. Paulson School of Engineering and Applied Sciences

Amount: DKK 2,000,043

Grant category: Research grants in open competition

Year: 2018

Geography: USA

We will develop a novel ionic-liquid formulation for topical delivery of nucleic acids into the skin.

Our ionic liquid enhances lipophilicity of nucleic acids by ~100,000,000 fold and enhances their penetration into the skin. We will demonstrate the feasibility of the platform through delivery and efficacy of two siRNAs. The resulting platform is expected to have broad applications to other nucleic acid drugs including mRNA for the treatment of a wide range of dermatological conditions.

Our ionic liquid platform will open new opportunities for the treatment of dermatological conditions.