Low-dose calcipotriol can elicit wound closure, anti-microbial, and anti-neoplastic effects in epidermolysis bullosa keratinocytes

Skin Microbial Composition and Genetic Mutation Analysis in Precision Medicine for Epidermolysis Bullosa

Epidermolysis bullosa (EB) is an inherited skin disease representing a spectrum of rare genetic disorders. These conditions share the common trait that causes fragile skin, resulting in the development of blisters and erosions. The inheritance follows an autosomal pattern, and the array of clinical presentations leads to significant physical suffering, considerable morbidity, and mortality. Despite EB having no cure, effectively managing EB remains an exceptional challenge due to its rarity and complexity, occasionally casting a profound impact on the lives of affected individuals. Considering that EB management requires a multidisciplinary approach, this sometimes worsens the condition of patients with EB due to inappropriate handling. Thus, more appropriate and precise treatment management of EB is essentially needed. Advanced technology in medicine and health comes into the bioinformatics era. Including treatment for skin diseases, omics-based approaches aim to evaluate and handle better disease management and treatment. In this work, we review several approaches regarding the implementation of omics-based technology, including genetics, pathogenic mutation, skin microbiomics, and metagenomics analysis for EB. In addition, we highlight recent updates on the potential of metagenomics analysis in precision medicine for EB.

Topical Calcipotriol Plus Imiquimod Immunotherapy for Nonkeratinocyte Skin Cancers

Nonkeratinocyte cutaneous malignancies, including breast cancer cutaneous metastasis and melanoma in situ, are often poor surgical candidates. Imiquimod (IMQ), a toll-like receptor 7 agonist that activates innate immunity in the skin, is used to treat these cutaneous malignancies. However, IMQ's modest effect on the activation of adaptive immunity limits its efficacy as a monotherapy. In this study, we demonstrate that topical TSLP cytokine inducers-calcipotriol and retinoic acid-synergize with IMQ to activate CD4+ T-cell immunity against nonkeratinocyte cutaneous malignancies. Topical calcipotriol plus IMQ treatment reduced breast tumor growth compared with calcipotriol or IMQ alone (P < 0.0001). Calcipotriol plus IMQ-mediated tumor suppression was associated with significant infiltration of CD4+ effector T cells in the tumor microenvironment. Notably, topical calcipotriol plus IMQ immunotherapy enabled immune checkpoint blockade therapy to effectively control immunologically cold breast tumors, which was associated with induction of CD4+ T-cell immunity. Topical treatment with calcipotriol plus IMQ and retinoic acid plus IMQ also blocked subcutaneous melanoma growth. These findings highlight the synergistic effect of topical TSLP induction in combination with innate immune cell activation as an effective immunotherapy for malignancies affecting the skin.

Biomarker Discovery in Rare Malignancies: Development of a miRNA Signature for RDEB-cSCC

Machine learning has been proven to be a powerful tool in the identification of diagnostic tumor biomarkers but is often impeded in rare cancers due to small patient numbers. In patients suffering from recessive dystrophic epidermolysis bullosa (RDEB), early-in-life development of particularly aggressive cutaneous squamous-cell carcinomas (cSCCs) represents a major threat and timely detection is crucial to facilitate prompt tumor excision. As miRNAs have been shown to hold great potential as liquid biopsy markers, we characterized miRNA signatures derived from cultured primary cells specific for the potential detection of tumors in RDEB patients. To address the limitation in RDEB-sample accessibility, we analyzed the similarity of RDEB miRNA profiles with other tumor entities derived from the Cancer Genome Atlas (TCGA) repository. Due to the similarity in miRNA expression with RDEB-SCC, we used HN-SCC data to train a tumor prediction model. Three models with varying complexity using 33, 10 and 3 miRNAs were derived from the elastic net logistic regression model. The predictive performance of all three models was determined on an independent HN-SCC test dataset (AUC-ROC: 100%, 83% and 96%), as well as on cell-based RDEB miRNA-Seq data (AUC-ROC: 100%, 100% and 91%). In addition, the ability of the models to predict tumor samples based on RDEB exosomes (AUC-ROC: 100%, 93% and 100%) demonstrated the potential feasibility in a clinical setting. Our results support the feasibility of this approach to identify a diagnostic miRNA signature, by exploiting publicly available data and will lay the base for an improvement of early RDEB-SCC detection.

Innovations in the Treatment of Dystrophic Epidermolysis Bullosa (DEB): Current Landscape and Prospects

Dystrophic epidermolysis bullosa (DEB) is one of the major types of EB, a rare hereditary group of trauma-induced blistering skin disorders. DEB is caused by inherited pathogenic variants in the COL7A1 gene, which encodes type VII collagen, the major component of anchoring fibrils which maintain adhesion between the outer epidermis and underlying dermis. DEB can be subclassified into dominant (DDEB) and recessive (RDEB) forms. Generally, DDEB has a milder phenotype, while RDEB patients often have more extensive blistering, chronic inflammation, skin fibrosis, and a propensity for squamous cell carcinoma development, collectively impacting on daily activities and life expectancy. At present, best practice treatments are mostly supportive, and thus there is a considerable burden of disease with unmet therapeutic need. Over the last 20 years, considerable translational research efforts have focused on either trying to cure DEB by direct correction of the COL7A1 gene pathology, or by modifying secondary inflammation to lessen phenotypic severity and improve patient symptoms such as poor wound healing, itch, and pain. In this review, we provide an overview and update on various therapeutic innovations for DEB, including gene therapy, cell-based therapy, protein therapy, and disease-modifying and symptomatic control agents. We outline the progress and challenges for each treatment modality and identify likely prospects for future clinical impact.

The LL-37 domain: a clue to cathelicidin immunomodulatory response?

Host defense peptides (HDPs) are naturally occurring polypeptide sequences that, in addition to being active against bacteria, fungi, viruses, and other parasites, may stimulate immunomodulatory responses. Cathelicidins, a family of HDPs, are produced by diverse animal species, such as mammals, fish, birds, amphibians, and reptiles, to protect them against pathogen infections. These peptides have variable C-terminal domains responsible for their antimicrobial and immunomodulatory activities and a highly conserved N-terminal pre-pro region homologous to cathelin. Although cathelicidins are the major components of innate immunity, the molecular basis by which they induce an immune response is still unclear. In this review, we will address the role of the LL-37 domain and its SK-24, IV-20, FK-13 and LL-37 fragments in the immunity response. Other cathelicidins also share structural and functional characteristics with the LL-37 domain, suggesting that these fragments may be responsible for interaction between these peptides and receptors in humans. Fragments of the LL-37 domain can give us clues about how homologous cathelicidins, in general, induce an immune response. AVAILABILITY OF DATA AND MATERIAL: No data was used for the research described in the article.

FPR2 DNA Aptamers for Targeted Therapy of Wound Repair

Chronic wounds represent a major health problem worldwide. Some of the available therapies based on recombinant proteins usually fail owing to the hostile environment found at the wound bed. Aptamers appear as an attractive alternative to recombinant factors owing in part to their stability, sensitivity, specificity, and low-cost production. In this study, the Cell-Systematic Evolution of Ligands by EXponential Enrichment technology was employed to generate aptamers that specifically recognize and modulate the function of the FPR2, a receptor expressed in a variety of cells involved in wound repair. Three aptamers were obtained that specifically bound to FPR2 stable transfectants generated in HaCaT cells. The targeted aptamers were shown to act as FPR2 agonists in different in vitro functional assays, including wound healing assays, and elicited a similar pattern of response to that obtained with other known FPR2 peptide agonists, such as the human LL37 cathelicidin. We have also obtained in vivo evidence for the prohealing activities of one of these FPR2 aptamers in a skin-humanized mouse model developed by us, previously shown to accurately recreate the main phases of physiological human wound repair process. In conclusion, we provide evidence of the potential therapeutic value of FPR2 aptamers for cutaneous repair.

Epidermolysis Bullosa in children: the central role of the pediatrician

Epidermolysis bullosa (EB) is a severe hereditary disease characterized by defective epithelial adhesion causing mucocutaneous fragility. The major types are EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB) and more than 35 EB subtypes. Another very rare type of EB is Kindler EB (KEB). Clinically, it is a very heterogeneous disease which ranges from localized to extensive skin lesions with frequent multisystem extra cutaneous involvement. The role of a pediatrician-dermatologist cooperation within a multidisciplinary team is fundamental for both the diagnosis and management contributing to these patients' better life expectancy. Aim of this study is to describe clinical and laboratory characteristics of the main EB subtypes focusing on nutritional and gastrointestinal aspects, providing information to aid the paediatric management of children with EB. This retrospective study reviewed the cases of 160 pediatric EB patients (76 male and 84 female): 31 patients affected by EBS (mean age ± SD: 4.37 ± 7.14), 21 patients affected by JEB (mean age ± SD: 9.26± 17.30) and 108 with DEB (mean age ± SD: 11.61 ± 13.48). All patients were admitted at the Bambino Gesù Children's Hospital in Rome, between June 2005 to June 2020. The reduced gastrointestinal absorption, chronic losses, esophageal stenosis and chronic inflammatory state, represent the basis of nutritional problems of EB patients. In particular, anemia represents one of the most important complications of DEB patients which could require transfusion-dependent patterns. Malnutrition, vitamin deficiencies and anemia have been related to growth delay in EB patients. A specific diet with a balance of all macronutrients is required and improving caloric intake with sugar limitations is fundamental to prevent dental caries and tooth decay typical of EB patients. While sepsis proved to be the major cause of morbidity and mortality in younger patients, squamous cell carcinoma was mostly observed in older patients, especially those affected by DEB. Patients with EB require regular monitoring for complications and sequelae with a frequency of evaluations which varies based on age and EB subtypes. Cooperation among medical teams involving paediatricians, dermatologists, specialist clinicians including nutritionists such as families and patient's association is fundamental to approach the disease and improve the quality of life of these patients.

Epidermolysis Bullosa: A case study in Cyprus and the nursing care plan

PURPOSE

To present a case study with Epidermolysis bullosa (EB) in Cyprus and to determine the nursing care plan, explaining the nursing interventions and showing the importance of nursing care of patients with EB.

METHODS

Literature review on EB and semi-structured interviews commenced through a direct discussion with open-ended questions to the research subject as well as to a close relative describing his feelings, experiences, and concerns about the disease.

FINDINGS

Thematic analysis approach was used to identify and analyze patterns in the data. Then, data were synthesized using the standardized nursing terminology of NANDA-I and the Nursing Interventions Classification. The accuracy of the diagnoses and the appropriateness of the nursing interventions were supported by the positive health outcomes of the patient.

CONCLUSIONS

Nurses should apply evidence-based practice interventions for EB wound care, pain management, nutrition, psychological and social support to these patients.

IMPLICATIONS FOR NURSING PRACTICE

Although EB is classified in the category of rare diseases, the presentation of a case study in Cyprus and the nursing care plan contribute further bibliographically to the holistic and at the same time individualized nursing practice.

Challenges in Treating Genodermatoses: New Therapies at the Horizon

Genodermatoses are rare inherited skin diseases that frequently affect other organs. They often have marked effects on wellbeing and may cause early death. Progress in molecular genetics and translational research has unravelled many underlying pathological mechanisms, and in several disorders with high unmet need, has opened the way for the introduction of innovative treatments. One approach is to intervene where cell-signaling pathways are dysregulated, in the case of overactive pathways by the use of selective inhibitors, or when the activity of an essential factor is decreased by augmenting a molecular component to correct disequilibrium in the pathway. Where inflammatory reactions have been induced by a genetically altered protein, another possible approach is to suppress the inflammation directly. Depending on the nature of the genodermatosis, the implicated protein or even on the particular mutation, to correct the consequences or the genetic defect, may require a highly personalised stratagem. Repurposed drugs, can be used to bring about a "read through" strategy especially where the genetic defect induces premature termination codons. Sometimes the defective protein can be replaced by a normal functioning one. Cell therapies with allogeneic normal keratinocytes or fibroblasts may restore the integrity of diseased skin and allogeneic bone marrow or mesenchymal cells may additionally rescue other affected organs. Genetic engineering is expanding rapidly. The insertion of a normal functioning gene into cells of the recipient is since long explored. More recently, genome editing, allows reframing, insertion or deletion of exons or disruption of aberrantly functioning genes. There are now several examples where these stratagems are being explored in the (pre)clinical phase of therapeutic trial programmes. Another stratagem, designed to reduce the severity of a given disease involves the use of RNAi to attenuate expression of a harmful protein by decreasing abundance of the cognate transcript. Most of these strategies are short-lasting and will thus require intermittent life-long administration. In contrast, insertion of healthy copies of the relevant gene or editing the disease locus in the genome to correct harmful mutations in stem cells is more likely to induce a permanent cure. Here we discuss the potential advantages and drawbacks of applying these technologies in patients with these genetic conditions. Given the severity of many genodermatoses, prevention of transmission to future generations remains an important goal including offering reproductive choices, such as preimplantation genetic testing, which can allow selection of an unaffected embryo for transfer to the uterus.

Keratins as an Inflammation Trigger Point in Epidermolysis Bullosa Simplex

Epidermolysis bullosa simplex (EBS) is a group of inherited keratinopathies that, in most cases, arise due to mutations in keratins and lead to intraepidermal ruptures. The cellular pathology of most EBS subtypes is associated with the fragility of the intermediate filament network, cytolysis of the basal layer of the epidermis, or attenuation of hemidesmosomal/desmosomal components. Mutations in keratins 5/14 or in other genes that encode associated proteins induce structural disarrangements of different strengths depending on their locations in the genes. Keratin aggregates display impaired dynamics of assembly and diminished solubility and appear to be the trigger for endoplasmic reticulum (ER) stress upon being phosphorylated by MAPKs. Global changes in cellular signaling mainly occur in cases of severe dominant EBS mutations. The spectrum of changes initiated by phosphorylation includes the inhibition of proteasome degradation, TNF-α signaling activation, deregulated proliferation, abnormal cell migration, and impaired adherence of keratinocytes. ER stress also leads to the release of proinflammatory danger-associated molecular pattern (DAMP) molecules, which enhance avalanche-like inflammation. Many instances of positive feedback in the course of cellular stress and the development of sterile inflammation led to systemic chronic inflammation in EBS. This highlights the role of keratin in the maintenance of epidermal and immune homeostasis.

Impact of low-dose calcipotriol ointment on wound healing, pruritus and pain in patients with dystrophic epidermolysis bullosa: A randomized, double-blind, placebo-controlled trial

Background

Wound management is a critical factor when treating patients with the inherited skin fragility disease dystrophic epidermolysis bullosa (DEB). Due to genetic defects in structural proteins, skin and mucous epithelia are prone to blistering and chronic wounding upon minor trauma. Furthermore, these wounds are commonly associated with excessive pruritus and predispose to the development of life-threatening squamous cell carcinomas, underscoring the unmet need for new therapeutic options to improve wound healing in this patient cohort. Vitamin D3 is acknowledged to play an important role in wound healing by modulating different cellular processes that impact epidermal homeostasis and immune responses. In this study, we evaluate the safety and efficacy of low-dose calcipotriol, a vitamin D3 analogue, in promoting wound healing and reducing itch and pain in patients with DEB.

Methods

Eligible DEB patients, aged ≥ 6 years and with a known mutation in the COL7A1 gene, were recruited to a placebo-controlled, randomized, double blind, cross-over phase II monocentric clinical trial. Patients were required to have at least two wounds with a minimum size of 6 cm² per wound. The primary objective was to evaluate efficacy of daily topical application of a 0.05 µg/g calcipotriol ointment in reducing wound size within a 4-week treatment regimen. Secondary objectives were to assess safety, as well as the impact of treatment on pruritus, pain, and bacterial wound colonization in these patients.

Results

Six patients completed the clinical trial and were included into the final analysis. Topical low-dose calcipotriol treatment led to a significant reduction in wound area at day 14 compared to placebo (88.4% vs. 65.5%, P < 0.05). Patients also reported a significant reduction of pruritus with calcipotriol ointment compared to placebo over the entire course of the treatment as shown by itch scores of 3.16 vs 4.83 (P < 0.05) and 1.83 vs 5.52 (P < 0.0001) at days 14 and 28, respectively. Treatment with low-dose calcipotriol did not affect serum calcium levels and improved the species richness of the wound microbiome, albeit with no statistical significance.

Conclusions

Our results show that topical treatment with low-dose calcipotriol can accelerate wound closure and significantly reduces itch, and can be considered a safe and readily-available option to improve local wound care in DEB patients.

TrialRegistration EudraCT: 2016–001,967-35. Registered 28 June 2016, https://www.clinicaltrialsregister.eu/ctr-search/trial/2016-001967-35/AT

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02062-2.

Molekulare Diagnostik und Therapie der Epidermolysis bullosa

Unter Epidermolysis bullosa (EB) subsumiert man genetische Erkrankungen, die durch gesteigerte Hautfragilität mit Blasenbildung nach bereits geringen mechanischen Belastungen gekennzeichnet sind. Hochvariable kutane, extrakutane und Organmanifestationen verursachen eine signifikante Morbidität und Mortalität sowie eine hohe Krankheitslast für Betroffene und Angehörige. Obwohl derzeit nicht heilbar, eröffnen Fortschritte in der molekularen Charakterisierung pathogenetischer Prozesse, in den diagnostischen Techniken und molekularen Therapieansätzen neue Perspektiven. Neben korrektiven, potenziell kurativen Behandlungszugängen mit dem Ziel der Wiederherstellung der Funktion von Gen bzw. Protein stellen krankheitsmodifizierende Strategien eine wertvolle Ergänzung dar. Unter Letztere fallen symptomatische Therapien, die sekundär dysregulierte, den Phänotyp modulierende Entzündungskaskaden adressieren oder zielgerichtete Interventionen hinsichtlich bestimmter Symptome wie Fibrosierung, Juckreiz oder kanzerogener Zelltransformation. Molekulare Verfahren erlauben heute zudem, eine Diagnose und damit Prognose früher und präziser zu stellen, was die genetische Beratung erleichtert.

Das Management von EB-Patienten ist komplex und bedarf einer Spezialexpertise und multidisziplinär akkordierten Versorgung. Entsprechende Ressourcen halten designierte Expertisezentren wie das EB-Haus Austria vor, das als Mitglied des Europäischen Referenznetzwerks für Seltene Hauterkrankungen (ERN Skin) sowohl klinische Versorgung, Grundlagen- und klinische Forschungsaktivitäten sowie Zugang zu Aus- und Weiterbildungsprogrammen für Betroffene, Betreuende und medizinisches Fachpersonal gewährleistet.

A single intra-articular dose of vitamin D analog calcipotriol alleviates synovitis without adverse effects in rats

1,25-dihydroxyvitamin-D3 and its derivatives have shown anti-arthritic and chondroprotective effects in experimental animal models with prophylactic dosing. The purpose of this preliminary study was to test the efficacy and safety of calcipotriol, vitamin D analog, as a treatment for a fully-developed knee arthritis in Zymosan-induced arthritis (ZIA) model. Forty 5-month-old male Sprague-Dawley rats were randomized into three arthritis groups and a non-arthritic control group with no injections (10 rats/group). A day after Zymosan (0.1 mg) had been administrated into the right knee joints, the same knees were injected with calcipotriol (0.1 mg/kg), dexamethasone (0.1 mg/kg) or vehicle in a 100 μl volume. The left control knees were injected with saline (PBS) on two consecutive days. All injections, blood sampling and measurements were performed under general anesthesia on days 0, 1, 3 and 8. Internal organs and knees were harvested on day 8 and the histology of the whole knees was assessed blinded. Joints treated with calcipotriol showed a milder histological synovitis than those treated with vehicle (p = 0.041), but there was no statistically significant difference between the dexamethasone and vehicle groups. The clinical severity of arthritis did not differ between the arthritis groups measured by body temperature, swelling of the knee, thermal imaging, clinical scoring or cytokine levels on days 1, 3 and 8. Weight loss was bigger in rats treated with dexamethasone, propably due to loss of appetite,compared to other arthritis groups on days 2-3 (p<0.05). Study drugs did not influence serum calcium ion and glucose levels. Taken together, this preliminary study shows that a single intra-articular injection of calcipotriol reduces histological grade of synovitis a week after the local injection, but dexamethasone did not differ from the vehicle. Calcipotriol may have an early disease-modifying effect in the rat ZIA model without obvious side effects.

Personalized Development of Antisense Oligonucleotides for Exon Skipping Restores Type XVII Collagen Expression in Junctional Epidermolysis Bullosa

Intermediate junctional epidermolysis bullosa caused by mutations in the COL17A1 gene is characterized by the frequent development of blisters and erosions on the skin and mucous membranes. The rarity of the disease and the heterogeneity of the underlying mutations renders therapy developments challenging. However, the high number of short in-frame exons facilitates the use of antisense oligonucleotides (AON) to restore collagen 17 (C17) expression by inducing exon skipping. In a personalized approach, we designed and tested three AONs in combination with a cationic liposomal carrier for their ability to induce skipping of COL17A1 exon 7 in 2D culture and in 3D skin equivalents. We show that AON-induced exon skipping excludes the targeted exon from pre-mRNA processing, which restores the reading frame, leading to the expression of a slightly truncated protein. Furthermore, the expression and correct deposition of C17 at the dermal-epidermal junction indicates its functionality. Thus, we assume AON-mediated exon skipping to be a promising tool for the treatment of junctional epidermolysis bullosa, particularly applicable in a personalized manner for rare genotypes.

Prevalence, pathophysiology and management of itch in epidermolysis bullosa

Epidermolysis bullosa (EB) is a highly diverse group of inherited skin disorders, resulting from mutations in genes encoding proteins of the dermoepidermal junction. Itch (pruritus) is one of the most common symptoms across all EB subtypes. It occurs in blistered or wounded sites, or manifests as a generalized phenomenon, thereby affecting both intact skin and healing wounds. The mechanism of pruritus in EB is unclear. It is likely that skin inflammation secondary to barrier disruption, wound healing cascades and dysregulated activation of epidermal sensory nerve endings are all involved in its pathophysiology on the molecular and cellular level. Understanding these mechanisms in depth is crucial in developing optimized treatments for people with EB and improving quality of life. This review summarizes current evidence on the prevalence, mechanisms and management of itch in EB.

Translational perspectives to treat Epidermolysis bullosa-Where do we stand?

Epidermolysis bullosa (EB) is the prototypical example of genetic skin fragility disorders. Genotypic heterogeneity, modifier genes, epigenetic, biochemical and environmental factors alter and determine pathogenic traits and, ultimately, the wide and striking phenotypic variability in EB. Besides the primary structural-functional defect, chronic tissue damage with induction and dysregulation of inflammatory pathways is a common pathogenic mechanism in EB. In localized variants, the inflammatory aberrations may mainly affect the micromilieu of lesional skin, while a systemic inflammatory response was shown to contribute to the systemic morbidity in severe EB subtypes with extensive cutaneous involvement. Our continued understanding of the pathophysiology of EB, as well as advances in molecular technologies, has paved the way for translational therapeutic approaches. The spectrum comprises of corrective and symptom-relieving therapies that include innovative therapeutic options garnered from the bench, repurposed drugs approved for other diseases, as well as strategies for gene-, protein- and cell-based therapies. Immunological traits further define new targets of therapy, aimed at improving skin barrier restoration, microbial surveillance and infection control, wound healing and anti-neoplastic effects. Clinical availability and feasibility of these approaches for all EB patients and subtypes are currently limited, reflecting issues of efficacy, specificity, tolerability and safety. A multistep targeting approach and highly individualized, risk-stratified combinatory treatment plans will thus be essential for sustained efficacy and improved overall quality of life in EB.

Small molecule drug development for rare genodermatoses - evaluation of the current status in epidermolysis bullosa

Background

Hereditary epidermolysis bullosa (EB) comprises a heterogeneous group of rare genodermatoses, which are caused by mutations in genes involved in the maintenance of the structural and functional integrity of dermo-epidermal adhesion in various stratified epithelia. In severe variants, generalized skin disease, extracutaneous manifestations and multi-organ involvement cause considerable morbidity and mortality. Causal and early treatment by re-expression of a respective mutated gene is the major long-term goal in therapy development. However, characterization and targeted modulation of pathogenic molecular cascades in EB also holds great promise as a symptom-relieving approach to ameliorate phenotype, complications and quality of life. Small molecules are chemical structures of less than 900 Da that can diffuse across cell membranes and interfere with target biomolecules, thus influencing their function at different levels. They constitute the vast majority of active components of all approved drugs.

Methods

We performed PubMed and Google Scholar search for publications and screened FDA- and EMA-hosted clinical trial registries to identify studies using small molecule-based drugs for epidermolysis bullosa. Upon detailed analysis this resulted in the identification of a total of 84 studies.

Results

We identified 52 publications and 32 registered trials that investigate small molecules for their safety and efficacy as treatment for different aspects of epidermolysis bullosa. Further, a total of 38 different small molecules clinically used in EB were found. Most frequent outcome measures concerned wound healing, reduction in blister numbers, as well as reduction of itch and pain, predominantly for EBS and RDEB.

Conclusion

We provide a comprehensive summary of the current status of clinical small molecule development for EB and discuss prospects and limitations in orphan drug development for rare conditions like EB.

Vitamin D3 analogue facilitates epithelial wound healing through promoting epithelial-mesenchymal transition via the Hippo pathway

BACKGROUND

Wound healing is a complex physiological process that is crucial for reestablishing the epithelial barrier following injury.

OBJECTIVE

The aim of this study was to demonstrate the efficacy of calcipotriol, a synthetic vitamin D3 analogue, in wound healing in an acute mice wound model.

METHODS

An excision wound model was established in mice, and the wound healing activity of calcipotriol was evaluated. Human keratinocyte cell lines, HaCaT and NHEK, were utilized in in vitro skin wound healing model. Cytokine expression levels were measured by real-time PCR and ELISA assay. The expression of epithelial-mesenchymal transition (EMT)-associated molecules and the phosphorylation of Yes-associated protein (YAP) was determined by western blotting.

RESULTS

The increase in re-epithelialization by calcipotriol treatment early in the wound was associated with the EMT process. A scratch assay using HaCaT and NHEK cells also showed that calcipotriol administration resulted in effective wound closure. We demonstrated that calcipotriol promoted keratinocyte migration by interfering with the Hippo pathway. Calcipotriol-mediated enhancement of cell migration is related to downregulated phosphorylation of YAP and increased levels of YAP and PDZ-binding motif (TAZ). Mechanistically, we defined that calcipotriol facilitated the crosstalk between the YAP/TAZ and TGF-β/Smad signaling pathways, eliciting EMT in keratinocytes during the wound healing process.

CONCLUSIONS

These results suggest that the positive effect of calcipotriol on keratinocyte migration is mediated by the induction of EMT via the regulation of Hippo pathway, which promotes the acceleration of wound closure.

EB (epidermolysis bullosa)-House Austria: Pioneering work for the care of patients with rare diseases

The care of patients with epidermolysis bullosa (EB) poses a major challenge due to the rarity, heterogeneity and complexity of the disease as well as the occurrence of numerous primary and secondary extracutaneous manifestations, causing a significant morbidity and mortality. Specialized treatment centers are essential for offering these patients adequate care, including individual, interdisciplinary coordinated treatments according to current medical standards, and access to innovative therapeutic options. Against this background, the EB House Austria was founded in 2005 and designated the first national center of expertise for genodermatoses with a focus on EB in 2017. In the same year, it became a member of the European Reference Network for Rare Skin Diseases (ERN Skin). The pillars of this institution (outpatient clinic, research unit, academy, clinical study center) interact closely with each other, with numerous national and international clinical and scientific partners, as well as with patients and their relatives via the DEBRA Austria patient group. The development of the EB House Austria as a reference center is characterized by a long-term pioneering work, which in turn could pave the way for the optimization of care for comparable diseases as well as general care structures.

Natural history of growth and anaemia in children with epidermolysis bullosa: a retrospective cohort study

BACKGROUND

Impaired growth and anaemia are major extracutaneous complications of epidermolysis bullosa (EB), but data on their development are lacking.

OBJECTIVES

To determine the clinical course of growth and anaemia in children with EB and clarify the impact of nutritional compromise, inflammation and genetic factors.

METHODS

A retrospective study was conducted of 200 children, 157 with recessive dystrophic EB (RDEB) and 43 with junctional EB (JEB)-generalized intermediate, followed at the main referral centre in Germany. Growth charts were calculated using the modified LMS method and were correlated with parameters of anaemia, nutrition, inflammation and the molecular defect in a linear model.

RESULTS

In our cohort of patients with RDEB, weight impairment started at 12-18 months old; by the age of 10 years, 50% showed wasting. The predicted median weight at age 20 years was 35·2 kg for men and 40·1 kg for women. In JEB, growth resembled that of healthy children. Anaemia was present from the second year of life onwards in RDEB and JEB. Low levels of haemoglobin, iron, vitamin D, zinc and albumin, high levels of C-reactive protein, and absence of collagen VII correlated significantly with low weight in RDEB. No correlation was observed in JEB.

CONCLUSIONS

The results highlight that nutritional compromise occurs early in children with RDEB and therefore may require interventions as of the first year or two of life. What's already known about this topic? Children with epidermolysis bullosa (EB) suffer from failure to thrive and anaemia as major extracutaneous complications. The course of growth and the development of anaemia in EB are poorly characterized. What does this study add? A molecularly well characterized cohort of 200 children with EB was followed with regard to anthropometrics, anaemia and inflammation. We demonstrate early onset of growth failure and anaemia, most pronounced in the subset of recessive dystrophic EB. Awareness of early growth delay and nutritional deficiencies will improve EB care in daily practice.

Epidermolysis bullosa: Advances in research and treatment

Epidermolysis bullosa (EB) is the umbrella term for a group of rare inherited skin fragility disorders caused by mutations in at least 20 different genes. There is no cure for any of the subtypes of EB resulting from different mutations, and current therapy only focuses on the management of wounds and pain. Novel effective therapeutic approaches are therefore urgently required. Strategies include gene-, protein- and cell-based therapies. This review discusses molecular procedures currently under investigation at the EB House Austria, a designated Centre of Expertise implemented in the European Reference Network for Rare and Undiagnosed Skin Diseases. Current clinical research activities at the EB House Austria include newly developed candidate substances that have emerged out of our translational research initiatives as well as already commercially available medications that are applied in off-licensed indications. Squamous cell carcinoma is the major cause of death in severe forms of EB. We are evaluating immunotherapy using an anti-PD1 monoclonal antibody as a palliative treatment option for locally advanced or metastatic squamous cell carcinoma of the skin unresponsive to previous systemic therapy. In addition, we are evaluating topical calcipotriol and topical diacerein as potential agents to improve the healing of skin wounds in EBS patients. Finally, the review will highlight the recent advancements of gene therapy development for EB.