tbuckley/cabot-search huggingface dataset:
O20 Dissecting junctional epidermolysis bullosa heterogeneity
Authors: Priya Garcha, Eleri Jones, Abubkr Abdelaal Ahmed, Monique Aumailley, Emanuel Rognoni, Matthew Caley
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Epidermolysis bullosa (EB) is a family of rare, incurable, inherited disorders that are characterized by extreme skin and mucosal fragility. One of the most severe forms is junctional EB (JEB). JEB is caused by mutations in genes encoding the skin basement membrane proteins laminin 332 (α3, β3, γ2), type XVII collagen or integrin α6β4. Despite similarities between the disease pathology of JEB and other forms of EB there is a dramatic reduction in life expectancy for patients with JEB. Patients with JEB rarely survive beyond the first year of life. To investigate this disparity, we have optimized a previously published conditional tamoxifen induced knockout JEB mouse model (Lama3flx/flxK14CreERT). This mouse model recapitulates all key features of JEB, such as thickening of the epidermis and visible blistering owing to the loss of laminin α3 at the basement membrane. Methods Single-cell (sc)RNA-Seq analysis was conducted on pooled skin samples from a healthy (control) and JEB mouse model (n = 3 per genotype). Immunofluorescent staining was conducted to confirm scRNA-Seq analysis including markers for skin differentiation (K14, transglutaminase 1, loricrin), proliferation (Ki67), basement membrane (laminin α3, laminin β3, laminin γ2, collagen VII) and immune markers (F4/80, Ly6-G/C, CD3, CD79). Results We can see large differences in cellular populations across the two conditions. With increased T- and B-immune-cell subpopulations in the JEB model compared with the healthy control. Utilizing CellChatDB we identified disease-specific signalling pathways that identify activated T- and B-cell populations interacting with JEB macrophage populations via proinflammatory pathways. Conclusions We have utilized an in vivo mouse model to gain insight into the molecular and cellular differences in a JEB diseased phenotype. Identifying changes in cellular pathways could be used as a targeted approach to identify a beneficial therapeutic treatment for JEB.
P27 Chloride intracellular channel 4 is a global regulator of type 1 interferon signalling in systemic sclerosis skin
Authors: Christopher Wasson, Sophie Dibb, Jessica Bryon, Begoña Caballero-Ruiz, Eva Clavane, Rebecca Wells, Vishal Kakkar, Enrico De Lorenzis, Rebecca Ross, Paul Meakin, Francesco Del Galdo
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Systemic sclerosis (SSc) is an autoimmune disease in which an immune-related injury induces fibrosis of the skin and can progress to affect the internal organs in the most serve cases. Aberrant type 1 interferon (IFN) signalling in the keratinocytes plays a major role in SSc disease progression. We have previously shown the chloride intracellular channel 4 (CLIC)4 is upregulated in SSc skin fibroblasts and plays an important role in SSc fibrosis by enhancing transforming growth factor-β signalling. In this study, we investigated the role of CLIC4 in SSc keratinocyte biology. Methods Skin biopsies from patients with SSc (N = 6) and healthy controls (HCs) (N = 6) were analysed by immunohistochemistry for the expression of CLIC4 and phosphorylated signal transducer and activator of transcription (STAT)1. The skin keratinocyte cell line HaCaTs was stimulated with a range of type 1 IFN signalling agonists including POLY I:C, POLY dA:dT, ODN 2216 and IFN-α. CLIC4 was inhibited with the chloride channel inhibitors NPPB and IAA-94 or small interfering RNA specific to CLIC4. Conditioned media from HC or SSc dermal fibroblasts was employed for indirect coculture of HaCaTs. Results Skin biopsies from SSc showed high levels of CLIC4 in SSc skin fibroblasts, keratinocytes and endothelial cells compared with HC. Indirect coculture of HaCaTs with SSc fibroblast media induced CLIC4 expression in the HaCaTs. The increased CLIC4 expression played an important role in type 1 IFN signalling in keratinocytes as inhibition of CLIC4 blocked Toll-like receptor (TLR)3, TLR9 and cGAS-mediated activation of the type 1 IFN signalling pathway transcription factor STAT1. Additionally, inhibition of CLIC4 prevented SSc fibroblast media from inducing a type 1 IFN response in keratinocytes. Conclusions The data presented in this study suggests that CLIC4 is a global regulator of the type 1 IFN signalling cascade in SSc epithelial cells.
P01 Remodelling of the dermoepidermal junction occurs in intrinsically aged Far East Asian skin without significant epidermal atrophy
Authors: Zoe Lim, Declan Lunny, Carine Bonnard, Abigail Langton, Rachel Watson
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Ageing is characterized by a gradual decline in physiological function and is influenced by both intrinsic genetic and extrinsic lifestyle and environmental factors. However, much of our knowledge of cutaneous ageing comes from the study of White populations. We have previously shown that the organization of young healthy skin is ethnicity-dependent and that altered epidermal morphology in White volunteers correlates with loss of biomechanical function in the skin. In this study, we used epidermal morphometry to determine whether parameters associated with intrinsic skin ageing in White skin are also observed in Far East Asian skin. Methods Archival skin samples were obtained from the Asian Skin Biobank [young (3–21 years), N = 38, 37 male samples (Chinese, n = 16; Malay, n = 16; other Far East, n = 6); aged (61–86 years), N = 7, one male sample (Chinese, n = 6; Malay, n = 1)] and stained with haematoxylin and eosin prior to image analysis for dermoepidermal junction (DEJ) convolution and measurement of epidermal thickness. Weigert’s resorcin-fuchsin stain was used to ensure samples were photoprotected. Results Weigert’s resorcin-fuchsin stain revealed that all samples were photoprotected, with no evidence of solar elastosis. We next compared whether geographic ancestry of our local Far East Asian population impacted epidermal morphology in young skin; neither DEJ convolution nor epidermal thickness were impacted by geographic ancestry. However, a significant flattening of the DEJ was observed between young and aged samples (P &amp;lt; 0.01). Interestingly, no significant difference in epidermal thickness was observed as a function of age. Conclusions While intrinsically aged Asian skin undergoes the same flattening of the DEJ that is seen in White populations, epidermal thickness does not significantly alter; this is in stark contrast to intrinsically aged White skin, where epidermal atrophy is observed. Hence, the trajectory of intrinsic cutaneous ageing may be ethnicity-dependent, providing further evidence that studies of skin from different ethnicities are necessary.
O11 Investigating the genetic basis of the influence of adiposity on psoriasis
Authors: Ravi Ramessur, Jake Saklatvala, Satveer Mahil, Jonathan Barker, Mari Loset, Nick Dand, Michael Simpson, Catherine Smith
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Obesity is a chronic inflammatory state that is highly prevalent in people with psoriasis. There is evidence to suggest that increasing levels of adiposity promotes the risk of psoriasis development and worsens disease severity. The degree to which adiposity influences psoriasis varies between individuals, and it is also unclear which key genetic factors underpin this variation. Identifying this could be mechanistically informative in uncovering immunological pathways connecting adiposity and psoriasis. This project explores the hypothesis that the influence of adiposity on psoriasis has a genetic basis. Methods Firstly, we examined the comparative strength of association between a range of measures of adiposity and psoriasis in a population-based study (UK Biobank, n = 336 806). Secondly, we performed a genome-wide by environment interaction study (GWEIS) meta-analysis examining the interaction between key measures of adiposity and psoriasis susceptibility in two large population-based studies [UK Biobank and HUNT (n = 164 753)]. Thirdly, in view of this association between human leucocyte antigen (HLA)-C*06:02 and higher adiposity levels in psoriasis, we wanted to explore whether biological differences existed between HLA-stratified subgroups. To explore this, we performed HLA-C*06:02-stratified Mendelian randomization to establish whether a difference in causal effect of adiposity on psoriasis existed between subgroups. Results We found that measures of central obesity (including impedance and dual-energy x-ray absorptiometry/magnetic resonance imaging measures) were most strongly associated with both psoriasis risk and severity. A sexual dimorphism was observed, with a stronger effect in men compared with women. Through GWEIS meta-analysis, we found a significant interaction between HLA-C*06:02-status and waist circumference on psoriasis risk (P = 3.69e−08). No significant difference in causal effect of body mass index or waist circumference on psoriasis risk were found in HLA-C*06:02-stratified subgroups. Conclusions These findings underscore the significance of central adiposity in influencing psoriasis risk. This study also emphasizes both the value and limitations of HLA-C*06:02 as a potential biomarker for distinguishing metabolically-driven psoriasis.
P20 Characterizing monoamine signalling in human dermal fibroblasts and keratinocytes
Authors: Tomas Andriuskevicius, Brenna Parke, Anna Rhodes, Leigh Knight, Parastoo Hashemi, Claire A Higgins
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Our mental health depends upon a fine balance of monoamines in the brain. Interestingly, there is ample evidence indicating that mental health disorders such as stress or anxiety have an impact on skin condition and appearance. For example, stress induces neurogenic inflammation, which in turn leads to mast cell degranulation in the skin and increases local histamine levels. This increased histamine within the skin exacerbates skin conditions such as eczema and psoriasis, while impacting the skin barrier. In this study, we first sought to investigate monoamine signalling in both skin keratinocytes and fibroblasts, with a specific focus on histamine and serotonin modulation. Next, we investigated mechanisms of release via pharmacological intervention to block corresponding receptors, informed by using single-cell RNA sequencing from existing datasets. Methods We adapted a powerful electrochemical technique, fast-scan cyclic voltammetry (FSCV) to codetect monoamine signalling in real-time in vitro. Employing the advanced capabilities of our artificial neural network models, we analysed extensive FSCV colour plot data in real-time to establish neurotransmitter release patterns and understand their characteristics. Results Our Results show that both keratinocytes and fibroblasts are capable of releasing serotonin and histamine without external intervention. After administering diphenhydramine, an H1 receptor inhibitor, to the cells, we observed a rise in the frequency and amplitude of both serotonin and histamine signalling compared with the cells that received no treatment. However, bafilomycin, a vacuolar H+ ATPase inhibitor, reduced the signalling frequency significantly. This suggests a potential autoregulation mechanism and interdependency between the two monoamines. Conclusions Overall, using analytical Methods, our work shows that skin-resident fibroblasts and keratinocytes can release monoamines including serotonin and histamine. This finding provides an opportunity to examine interventions that facilitate serotonin release, to decrease histamine levels, and improve the skin function and general mental wellbeing.
P34 Evaluating the adaptation of the amputee skin owing to prosthesis use: a study using <i>in vivo</i> Raman spectroscopy
Authors: Jack Hayes, Jennifer Andrews, Tomas Andriuskevicius, Omar Abdelwahab, Tom Briggs, Peter Worsley, Claire Higgins, Marc Masen
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Lower limb prosthesis has proven to be an extremely successful intervention for amputees. However, to achieve adequate function, the device places significant friction and load on the skin, which leads to substantial skin breakdown. Current rehabilitation practices require skin to be ‘trained’ to perform a load-bearing role. Despite this, there are very high injury statistics for skin on the residual limb in the literature, we hypothesize that rehabilitation practices to adapt amputee skin are limited. Methods To interrogate this, we used in vivo Raman spectroscopy to evaluate the lower limbs of 13 unilateral lower limb amputees. This enabled us to assess how key constituents of the stratum corneum (SC) such as natural moisturizing factor (NMF), water and lipid content vary with depth. We also analysed sebum content to quantify cytokines present and performed mechanical characterization of the lower limb to investigate stiffness and friction. Results We found that the Raman spectra of the amputated limb show reduced NMF, lipid content and water content at the top of the SC when compared with the intact limb (P &amp;lt; 0.05). In addition, we found that amputee skin contains higher levels of inflammatory cytokines compared with control skin. We also recorded that skin on the residuum is four times softer than the intact limb, while friction is much higher at 0.5 on the residuum skin, compared with 0.3 on the intact limb. Conclusions Here, we show the adaptations of amputee skin in response to rehabilitation to be minimal. Contrary to the dogma that rehabilitation trains skin to bear load, we found that skin barrier function in amputee skin is impaired, as indicated by altered water and lipid profile in addition to higher baseline inflammation.
P25 Identification of early changes in extracellular microRNA biomarkers of scleroderma for point-of-care diagnosis
Authors: Oliver Teenan, Ahmad Kenaan, Francesco Delgaldo, Christina Malaktou, Jessica Strid, Connor Daniels, Sylvain Ladame, Claire Higgins
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Scleroderma is a rare autoimmune disease, characterized by excessive extracellular matrix deposition leading to chronic inflammation and fibrosis. As a progressive disease initially affecting the skin, it presents similarly to Raynaud phenomenon, which delays diagnosis and treatment. Clinical diagnostic tests lack sensitivity, therefore novel Methods of detection and sensitive biomarkers are required to improve diagnosis rates. MicroRNAs are short, stable, noncoding RNAs, often present in the extracellular space, and can be sampled from interstitial skin fluid (ISF) through the employment of hydrogel microneedles. We aim to use this technique to improve upon current clinical gold standards of diagnosing scleroderma, at earlier stages of the disease. Methods In this study, we performed next-generation small-RNA sequencing on ISF from healthy individuals, patients prior to a clinical diagnosis of scleroderma [termed very early detection of systemic sclerosis (VEDOSS)], and patients with scleroderma classified as low and high skin score, identifying a panel of microRNA biomarkers for scleroderma diagnosis. Swellable hydrogel microneedles were manufactured in house, applied to excised human tissue and preclinical mouse models to demonstrate the ability to access and quantify extracellular microRNAs in ISF. Results Patients who received a VEDOSS diagnosis have increased ISF abundance of miR-379-5p and miR-125a-5p and decreased miR-30e-3p compared with healthy patients. miR-379-5p, miR-363-3p and miR-221-3p are sensitive to the progression of scleroderma and could be used to track the disease with improved sensitivity to autoantibodies in blood or where clinical practices usually require a skin biopsy. Using preclinical models of skin disease, we could differentiate between conditions, with higher sensitivity than blood sampling using our microneedle technology. Conclusions By identifying extracellular mircoRNAs, we have shown the potential use of these sensitive biomarkers in a liquid biopsy that can be applied at point-of-care. Peptide nucleic acids complementary to our microRNA biomarkers, will be used to provide real-time on-the-chip readouts of these ­biomarkers.
P35 Adaptation of a phenotypic screening assay to incorporate 384-well plates: opening the door to high-throughput screening
Authors: Kieran Feltham, Alice Lapthorn, Marcus Ilg, Peter Dziewulski, Selim Cellek
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims High-throughput screening has significantly impacted drug discovery by increasing speed of experiments and reducing reagent and sample costs. We have previously developed several screening assays to measure myofibroblast inhibition via quantification of α-smooth muscle actin (α-SMA) expression, in a 96-well format. Currently, there are no drugs for the treatment of hypertrophic scarring, a major side-effect of burn injuries that occurs by myofibroblast transformation, leaving a huge gap in this sector. The aim for this project was to adapt our current assay for use in 384-well microplates. Methods Human primary dermal fibroblasts were transformed to myofibroblasts using 10 ng mL−1 transforming growth factor (TGF)-β1. α-SMA expression was measured using the In-Cell enzyme-linked immunosorbent assay method, with cell viability measured using DRAQ5 nuclear staining. Assay accuracy and reliability was determined by calculating the robust z-factor, with guidelines set to an average score over 0.5, with a minimum score per plate above 0.4. To further validate the assay, concentration-response curves (CRCs) for the drug vehicle [dimethyl sulfoxide (DMSO)] and our tool compound (SB-505124) were constructed at varying concentrations, in coincubation with TGF-β1. Results Optimization of well metrics was performed, producing an average robust z-factor of 0.52, confirming the assay Results are reliable and reproducible. The DMSO CRC produced no significant drop in cell viability at concentrations that are expected to be used in the screening of compounds. Our tool compound (SB-505124) produced a concentration-dependant curve for the inhibition of myofibroblast transformation. Conclusions A 384-well assay has been designed, tested and validated for the determination of myofibroblast transformation in human primary dermal fibroblasts. The assay has been shown to deliver an average robust z-factor of above 0.5, it contains a positive control and is compatible with compounds stored in up to 100% DMSO.
P05 The aryl hydrocarbon receptor pathway is dysfunctional in atopic dermatitis
Authors: Hannah Dawe, Isabella Tosi, Jonathan Barker, Catherine Smith, Paola Di Meglio
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by epidermal barrier disruption and type-2 immune dysregulation. While treatment has improved with targeted biologics, clinical response varies, highlighting the need for additional therapeutic strategies. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor and environmental sensor, which maintains skin barrier integrity and homeostasis by reducing inflammation. Upon activation, AHR induces the expression of CYP1A1, a biomarker of pathway activation and critical for AHR ligand metabolism. Tapinarof, a topical AHR agonist, is approved for psoriasis and is effective in phase III clinical trials in AD, highlighting the importance of this pathway in inflammatory skin disease. Nevertheless, AHR expression is increased in AD skin, leading to the hypothesis that the pathway is dysregulated, thus not exerting its anti-inflammatory effect. Methods Here we begin to perform a global investigation of the AHR pathway in AD. We measured AHR and CYP1A1 mRNA expression by quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) in healthy and AD skin, with spatial mRNA expression assessed by RNAscope. We also investigated AHR mRNA expression in interleukin (IL)-4 stimulated (100 ng mL−1) normal human epidermal keratinocytes (NHEKs) using qRT-PCR. Results We found that AHR mRNA is significantly upregulated in lesional AD (n = 6) compared with healthy skin (n = 9; P &amp;lt; 0.05), whereas CYP1A1 mRNA expression shows a downward trend in lesional AD compared with healthy skin (P = 0.063). The AHR expression pattern differs in lesional AD (n = 7) compared with healthy skin (n = 8), with AHR localizing in the epidermal basal layer. Finally, IL-4 significantly upregulated AHR mRNA (n = 4 wells; P &amp;lt; 0.001) expression in NHEKs compared with unstimulated cells. Conclusions Overall, our data have uncovered a dysfunctional AHR pathway in AD, with increased AHR expression, possibly driven by the AD inflammatory milieu, but reduced pathway activation. Further investigations are required to fully dissect this pathway and maximize its potential as a therapeutic target for AD.
O10 Tuneable Caf1 protein polymers as an innovative and scalable solution for regenerative wound care
Authors: Yuanjinze Nie, Helen Waller, Daniel Peter, Nick Reynolds, Jeremy Lakey
Journal: British Journal of Dermatology (2024)

Abstract Introduction and aims Wound healing is a complex process essential for tissue restoration, where the extracellular matrix (ECM) plays a crucial role by providing structural and biochemical support to cells. Laminin 332, a key ECM component, is a promising target for protein-based therapeutics in view of its pathogenic role in junctional epidermolysis bullosa (JEB). Bioengineered capsular antigen F1 protein (Caf1) has emerged as a potential candidate molecule. We have developed the technology to enable bacteria to produce Caf1 polymers with multiple tailored bioactive motifs. Additionally, the unique properties of Caf1 minimize the potential for a host immune response. In this study, we engineered Caf1 proteins to express specific synthetic basement membrane components related to laminin 332 with the aim of restoring ECM equilibrium and achieving effective wound healing. Methods To evaluate Caf1 construct effects on human epidermal keratinocytes (HEKs) (CCD 1106) and human dermal fibroblasts (HDFs), scratch assays were performed under different treatment with Caf constructs. The Incucyte® ZOOM system (Sartorius AG, Göttingen, Germany) automated scratch wound and Live-Cell Analysis System screened constructs enhancing wound healing, capturing images every 2 h. Analysis involved quantifying the area under the curve of wound confluence (%) over 72 h to assess wound closure. Results The migration of HDFs was enhanced by 10.4% ± 0.95% (P &amp;lt; 0.05 Anova, n = 9 independent experiments) when there was interaction with Caf1-CTB4 (PMQKMRGDVFSP). The migration of CCDs was enhanced by 12.7% ± 1.03% when interacting with Caf1-J3 (KNSFMALYLSKGR) and by 14.4% ± 1.11% when interacting with Caf1-J4 (TALIRATYGEYSTGYI) (P &amp;lt; 0.05 Anova; n = 3 independent experiments). Combining Caf1-J3 and Caf1-J4 synergistically boosts CCD migration by 19.1% ± 1.42% (P &amp;lt; 0.05 Anova; n = 3 independent experiments), yielding better Results compared with individual treatments. Conclusions Caf1 exhibits promise as a platform for motif delivery, and the incorporation of cell migration motifs into Caf1 holds the potential to enhance wound healing.