Experimental Dermatology

Introduction: There is an unmet need for effective topical anti-pruritic medications for acute itch, as there are only a few over-the-counter products that have a direct effect on itch. Tripelennamine is a first-generation antihistamine that would be useful in treating histamine-induced pruritus, however, supportive robust clinical data is lacking. Objectives: The efficacy of tripelennamine (TPA) compared to diphenhydramine (DPH) and a vehicle control cream base on histamine-induced pruritus was evaluated as the primary endpoint. Histamine-induced urticaria served as the secondary endpoint. Methods: Thirty-six healthy participants completed this single-center, double-blinded, placebo-controlled crossover clinical study. Following pretreatment with TPA1%, DPH 1% or vehicle control creams, histamine challenge occurred via iontophoresis and a visual analog scale (VAS) for pruritus was used to determine extent of itch (AUC-VAS), peak itch, and duration of itch. Results: Compared to the vehicle control, TPA reduced histamine-induced extent of itch (AUC-VAS), peak itch, and itch duration by 59%, 38% and 43%, respectively (p<0.01 all). DPH did not significantly affect these responses and TPA was superior in reducing extent of itch (48% reduction, p<0.05) and duration (38% shorter, p<0.05). TPA, but not DPH, also reduced histamine induced flare and wheal responses (secondary endpoints) by 53% and 27%, respectively. The reduction in flare responses by TPA was superior to that of DPH (45% reduction, p<0.05). Conclusion: TPA significantly attenuated histamine-induced pruritus and urticaria in a human histamine-challenge model and demonstrated greater efficacy than DPH. These findings provide strong evidence of the antipruritic activity of topical TPA and support further clinical investigation of TPA as a treatment for histaminergic itch and related dermatologic conditions.

PurposeFuchs endothelial corneal dystrophy (FECD) is a progressive disease, causing premature death of corneal endothelial cells (CECs). Iron-dependent lipid peroxidation and ferroptosis mediate cell death in FECD. We aimed to determine whether FECD progression is mediated by derangements in ferritinophagy - a form of autophagy that degrades ferritin to release labile ferrous iron - and whether ultraviolet A (UVA) exposure drives FECD progression by activating ferritinophagy. MethodsEndothelium-Descemet membrane (EDM) tissues were collected from patients with end-stage FECD undergoing endothelial keratoplasty and from healthy age-matched donor corneas. Separately, immortalized FECD and healthy control CEC lines were cultured. Cellular levels of NCOA4 production and LC3 activation, both markers of ferritinophagy, were quantified using western blotting and PCR. UVA-exposed immortalized cells were plated on coverslips, stained for immunohistochemistry (IHC), and analyzed using confocal microscopy. Corneal endothelial peels were stained and analyzed using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). ResultsSurgically explanted FECD CECs showed significantly increased levels of NCOA4 compared to healthy controls. LC3 activation was increased in FECD immortalized CECs; UV exposure further increased LC3 activation. Additionally, UVA exposure showed trends of increased expression of NCOA4 in immortalized FECD and healthy CECs. On IHC of FECD surgical explant tissue, ferritin was decreased markedly, NCOA4 localized in a dramatic punctate pattern, and both ferritin and LC3 localized within cell nuclei. Spectrometry images showed higher iron levels correlating with areas of higher FECD disease burden. ConclusionsOur results demonstrate ferritinophagy in FECD indicated by the increase of NCOA4 and LC3 ferritinophagy markers in FECD patient and cell culture models. Our finding that UVA activates ferritinophagy implicates this mechanism in UVA-mediated FECD progression. Altogether, aberrant iron dysregulation associated with FECD and ferroptosis may be mediated by ferritinophagy, providing a biomarker to assess disease severity as well as a potential target for future medical therapeutics.

Compared with skin wounds, oral mucosal wounds heal more quickly, with minimal scarring, faster re-epithelialization, and reduced inflammation. One differentiating factor may be the differential transcription factor-associated gene networks involved in tissue regeneration. One such transcription factor, BATF3, was recently shown by us to promote wound-healing responses in vitro and in vivo. Our prior analyses also suggest that CREB5 is a differentially regulated transcription factor in oral wounds and may be involved in early wound-healing gene expression programs. CREB5 expression was induced in immortalized skin keratinocytes (HaCaT) to examine its effect on in vitro wound healing relative to immortalized gingival keratinocytes (TIGK). CREB5 overexpression let to differential expression of predicted downstream genes and improved skin keratinocyte migration in vitro. This work suggests that examining transcription factors and gene networks that regulate wound-healing responses in the oral mucosa may lead to the discovery of novel targets to improve skin wound healing.

Keratinocyte proliferation and differentiation are essential to produce the stratified structure of the epidermis and maintain its barrier function. These processes are regulated by complex mechanisms including epigenetic regulation. In this study, we evaluated the role of HDAC4/5, two class IIa histone deacetylases, in the epigenetic regulation of proliferative and differentiated human keratinocytes using dedicated 2D and 3D in vitro models. Our findings demonstrate that chemical inhibition or shRNA-mediated knock-down of HDAC4 impair keratinocyte proliferation notably through increased H3K27 acetylation and subsequent transcriptional activation of the cell cycle inhibitor gene BTG2. Interestingly, HDAC4/5 inhibition alters H3K27 acetylation landscape in proliferating keratinocytes, whereas the epigenetic identity of differentiated keratinocytes is much less affected. Inhibiting HDAC4/5 in 3D epidermis models resulted in reduced epidermal thickness and impaired barrier function linked to alteration in the lipid composition of the stratum corneum. Furthermore, analysis of several well-established skin aging markers revealed that reconstructed human epidermis treated with the HDAC4/5 inhibitor exhibit molecular and functional characteristics consistent with an aged-epidermis. Collectively, our results demonstrate that HDAC4/5 are essential for maintaining epidermal homeostasis and pave the way for the development of innovative models of skin aging based on the modulation of histone acetylation.

Despite known carcinogenic properties, indoor tanning remains popular among young adults and may contribute to early-onset melanoma. Our study aims to compare early-onset melanoma incidence by state availability of tanning beds. We analyzed population-based melanoma incidence data (2019-2023) from the National Program of Cancer Registries and calculated Incidence Rate Ratios (IRR) using verified state-level quintiles of tanning bed availability. Overall, in the Midwest/South regions, melanoma incidence increased with greater tanning-bed availability, from 8.7 cases per 100,000 population in Quintile 1 to 14.8 cases per 100,000 population in Quintile 5 (IRR = 1.69; CI = 1.65-1.74). No such relationship was found in the Northeast/West regions. In conclusion, we found that in Southern and Midwest states, increased availability of tanning beds was associated with higher early-onset melanoma in non-Hispanic White males and females, in both metro and non-metro counties. Policies which reduce tanning bed availability in high utilization regions may have potential to reduce early-onset melanoma.

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in older adults. It is characterised by early retinal pigment epithelium (RPE) dysfunction followed by progressive photoreceptor degeneration. Cigarette smoking is a major environmental risk factor for AMD, and hydroquinone (HQ), a redox-active cigarette smoke component, induces oxidative stress and apoptosis in RPE cells. To analyse how RPE stress contributes to photoreceptor degeneration, we employed a retinal co-culture model composed of human induced pluripotent stem cell-derived RPE (iPSC-RPE) cells in conjunction with porcine neuroretina explants. Exposure to HQ induced oxidative stress in iPSC-RPE cells as well as retinal photoreceptors (RPR), resulting in apoptosis, executed at least in part by caspase activation. Concomitantly, HQ caused endoplasmic reticulum (ER) stress (ERAD) in RPR followed by their degeneration, evidenced by reduced outer nuclear layer (ONL) rows and shortened RPR outer segments (OS). Based on earlier results, which suggest a perturbation of proteostasis due to HQ, we tested whether ML240, a bona fide inhibitor of valosin-containing protein (VCP), would influence the degree of degenerative activities. ML240 did not prevent HQ-induced apoptosis in iPSC-RPE cells. However, it significantly preserved photoreceptor integrity, retaining OS length and cone density in HQ-stressed co-cultures. Proteomic analysis suggested that ML240 reshapes stress response patterns of the HQ-exposed neuroretina, as evidenced by a reduction in ERAD-associated markers, increased levels of antioxidant response proteins, and the preservation of cytochrome c enrichment in photoreceptor inner segments, which indicates improved mitochondrial integrity consistent with the observed preservation of photoreceptor structure. Together, these findings establish the iPSC-RPE/neuroretina co-culture as a platform to analyse pathophysiological features of AMD, dissect cell type-specific retinal responses to environmental stress and test neuroprotective pharmacological approaches to protect photoreceptors in oxidative stress-associated retinal degeneration.

Background: Uveal melanoma (UM) and cutaneous melanoma (CM) both originate from the same cell line. This proposes the possibility of a shared mechanism between entities, requiring explicit investigation. Methods: Data from GWAS Catalog and DisGeNET were used to identify shared variation-disease associations (VDAs) between UM and CM. The results were validated using the Ensembl database. In the next step, the STRING database was used to identify the protein-protein interaction. Results: Subsequently, 109 unique VDAs were identified for UM and 880 for CM. However, only 2 VDAs were found to be shared among UM and CM in different ethnic groups. These shared VDAs were rs12203592 of the IRF4 gene, rs12913832 of the HECT and RLD domain-containing E3 ubiquitin protein ligase 2 (HERC2) gene. Notably, PPI network assessment through STRING showcased that OCA2 and IRF4 directly interacted with HERC2. Conclusion: While HERC2 acts as a poor prognostic factor in uveal melanoma, IRF4 status is a key prognostic indicator in both UM and CM. Identifying IRF4 allele contributions enables a better understanding of melanoma pathogenesis and fosters the development of disease-specific approaches.

Background: Pressure ulcers often develop complex three-dimensional morphologies that extend beyond the visible wound surface. Subsurface extensions such as tunneling and undermining create hidden cavities that complicate clinical assessment and wound management. Despite their clinical relevance, the prevalence and spatial characteristics of these subsurface wound morphologies have not been well characterized at scale. Methods: We performed a registry-based analysis using data from the LIFT-OFF Pressure Ulcer Registry, which captures longitudinal clinical documentation of pressure ulcers treated in routine care. The registry included approximately 18,000 patients with 32,000 documented pressure ulcers. Spatial characteristics of tunneling and undermining were analyzed using measurements recorded during routine wound assessments, including tract length, direction, and circumferential extent. Directional and circumferential distributions of subsurface defects were examined to characterize wound geometry. Results: Tunneling was present in 764 of 14,700 full-thickness pressure ulcers (5.2%), whereas undermining occurred in 2,293 wounds (15.6%). Tunneling tracts were typically short and exhibited directional clustering relative to the wound bed. In contrast, undermining demonstrated broader circumferential distributions and frequently involved larger subsurface separations beneath the wound margin. Both morphologies demonstrated distinct spatial patterns across anatomical locations and wound stages. Conclusion: Tunneling and undermining are common subsurface features of pressure ulcers and exhibit distinct spatial geometries. Whereas tunneling manifests as directional tract-like extensions, undermining more frequently produces circumferential tissue separation beneath wound margins. Improved characterization of subsurface wound architecture may enhance assessment of wound complexity and provide information not captured by surface measurements alone. Future studies should evaluate whether these features contribute to wound severity assessment, prognosis, and risk stratification.

BackgroundAcrodysostosis type 2 (ACRDYS2) is a rare autosomal dominant disease characterized by skeletal defects and cognitive deficit, with clinical symptoms observed in multiple other tissues including the skin. It is caused by mutations in a phosphodiesterase, PDE4D, a key regulator of cAMP/PKA (cyclic adenosine monophosphate / protein kinase A) signalling. Despite its well-defined genetic causes, the molecular mechanisms underlying the disease remain poorly understood, with studies based largely on engineered cellular models reaching conflicting interpretations. MethodsTo investigate how endogenous dynamics are affected by PDE4D mutations in unmanipulated cells, we studied PDE4D transcript and protein expression, activity and downstream signalling in native dermal fibroblast from ACRDYS2 patients and healthy controls. ResultsSignificant reduction in total PDE4D expression in patient cells was observed both at the transcript and protein level, with marked decreases in the long isoforms PDE4D4 and PDE4D7; a reduction in PDE4D9 mRNA was also observed. PDE4D enzymatic activity was reduced in ACRDYS2 fibroblasts, though total PDE activity was largely preserved. Reduced PDE4D expression was associated with an increase in the phosphorylated form of the cAMP-responsive transcription factor CREB and elevated PRKAR1A (PKA type 1 regulatory subunit alpha) transcript levels, suggesting altered downstream signalling. Interestingly, expression of the related phosphodiesterase family member PDE4B was increased, consistent with a compensatory response to reduced PDE4D function. ConclusionsThis is the first study demonstrating reduced PDE4D expression and isoform-specific dysregulation in native ACRDYS2 cells. Together, our results support a model in which reduction in PDE4D activity and compensatory changes in other PDE4 family members contribute to the molecular pathology of ACRDYS2, providing new insights into the molecular mechanisms underlying this disorder.

Mustard keratopathy, caused by exposure of the cornea to sulfur or nitrogen mustard vesicants, chemical warfare agents, can lead to severe and often irreversible vision loss. Despite considerable efforts to develop medical countermeasures, including anti-inflammatory, antioxidant, anti-fibrotic, and anti-angiogenic therapies, no treatment effectively targets the underlying mechanisms responsible for mustard-induced tissue injury or prevents long-term disease progression. In the present study, we comprehensively define mitochondrial mechanisms underlying nitrogen mustard-induced corneal injury in both our cell culture model in vitro and a mouse model in vivo. DNM1L (aka Drp1) is a mitochondria-localized dynamin-related GTPase that executes mitochondrial fission and facilitates the autophagic elimination of damaged mitochondrial components. Using complementary in vitro and in vivo models, we demonstrate that nitrogen mustard rapidly induces excessive mitochondrial fragmentation, bioenergetic collapse, membrane depolarization, oxidative stress, intracellular acidification, mitophagy, and apoptotic cell death. Pharmacological inhibition of DNM1L with Mdivi-1 preserves mitochondrial structure and function, restores cellular metabolism, reduces oxidative damage, and markedly improves corneal epithelial integrity, and tissue repair following nitrogen mustard exposure. Collectively, these findings establish mitochondrial dysfunction as a central pathological mechanism in mustard keratopathy and identify DNM1L-mediated mitochondrial remodeling as a therapeutically actionable target. Our work provides strong preclinical evidence supporting mitochondrial-directed therapy as a promising strategy for treating mustard keratopathy.

Induced pluripotent stem cells (iPSCs) hold great promise for both allogeneic and autologous cellular therapies. However, broad application and clinical translation is hindered by fragmented, complex and time-intensive workflows, resulting in high manufacturing costs, poor standardization and increased risk of genomic aberrations in derived iPSCs. In this study we developed a standardizable, automatable and time- efficient process for the derivation of monoclonal iPSC lines straight from skin including a comprehensive and cascaded OC strategy. We generated monoclonal iPSC lines derived from human skin punch biopsies of ten donors (age 49-81) via mRNA-based reprogramming that subsequently underwent comprehensive and thorough characterization of phenotypic and genetic properties. The use of a combined mechanical and enzymatic fibroblast isolation protocol and a transient non-integrative reprogramming technology allowed us to obtain 78 monoclonal iPSC lines, ready for banking, molecular characterization and further differentiation within seven weeks from initial sample processing to passage four iPSC lines. The phenotypical characterization via flow cytometry-based pluripotency marker expression and 2D-directed differentiation into the three germ layers showed low intra- and inter-donor variability over all generated lines. A combination of SNP array based CNV analysis followed by whole exome sequencing proved to be the most efficient approach for assessment of genomic integrity. Proof-of-concept experiments for closed system processing revealed that a substantial part of the most error-prone and technically demanding steps can be transferred to semi- automated, closed systems. In conclusion, the described protocol allows for time- efficient, standardizable and automatable generation of high-quality monoclonal iPSC lines from human skin punch biopsies within seven weeks, thus moving the field of autologous iPSC manufacturing one step further towards cost-efficient clinical implementation.

Blue light using Flavin (BLUF) proteins are microbial photoreceptors that are involved in various physiological responses. Their occurrence and biochemical properties in fungi remain poorly understood. Here, we investigated a putative BLUF photoreceptor from the corn-smut fungus Mycosarcoma maydis (MmBLUF). Domain analysis, multiple sequence alignment of BLUF core regions, and structural modelling indicated conserved canonical BLUF fold and flavin-pocket residues. However, when heterologously expressed, UV-visible and fluorescence spectroscopy revealed different spectral behaviour than canonical BLUF protein. Further, we tested the role of extended N-terminus in modulation of chromophore binding by expressing N-terminus truncated protein variants. Our results suggest that the unusual spectral behaviour is not linked to the truncation construct (extended N-terminus), which also showed similar spectral features, indicating that the extended N-terminus is unlikely to account for an unusual photodynamics characteristics. Our findings support MmBLUF as a structurally conserved putative fungal BLUF-like photoreceptor with different photochemical properties. Further studies are required to establish its chromophore identity, photocycle and function of this unusual BLUF-like domain from fungal system.

Traumatic optic neuropathy (TON) occurs due to direct or indirect injury to the optic nerve and is a significant cause of visual disability. So far, there is no effective treatment. The lack of understanding of the cellular mechanisms by which trauma induces inflammation and damage in retinal neurons is a critical knowledge gap in developing effective therapies. We have studied the role of the arginase 1 (A1) enzyme in this pathology. We have found previously that treatment with a long-acting form of human recombinant A1, pegylated A1 (PEG-A1) after optic nerve crush limits activation of retinal microglia and macrophages (M{Phi}) and reduces inflammation, thereby decreasing injury and protecting visual function. Here we report on studies designed to demonstrate the therapeutic efficacy of PEG-A1 in mouse models of direct and indirect TON and to elucidate the underlying mechanisms. We used ONC to model direct TON and sonication-induced trauma to the supraorbital rim to model indirect TON (SI-TON). At different times after injury, mice were treated with PEG-A1 which was delivered systemically by i.p. injection or locally by intravitreal injection. In order to assess the role of A1-induced activation of the ornithine/polyamine pathway in the protective effects of PEG-A1, some mice were treated with the ornithine decarboxylase (ODC) inhibitor, difluoromethylornithine (DFMO) immediately after the PEG-A1 treatment. Retinal function was determined by OptoMotry and electroretinography. Retinal injury and microglia/M{Phi} activation were assessed by immunofluorescence imaging. Expression of inflammatory cytokines was determined by Western blotting and quantitative RT PCR. Liquid chromatography mass spectrometry was used to analyze changes in arginase/ODC pathway metabolites. Results showed that PEG-A1 treatment improved neuronal survival and visual function whether delivered systemically or intravitreally. This neuroprotection was associated with decreased microglia/M{Phi} activation, decreased inflammatory cytokine expression, and increased formation of L-ornithine and putrescine. Furthermore, DFMO treatment blocked these effects, indicating that PEG-A1 limits retinal injury and preserves vision after ocular injury by activating ODC. ODC processes the arginase product L-ornithine to form polyamines which are known to promote reparative functions. Thus, PEG-A1 therapy offers a new strategy to limit trauma-induced vision loss and promote repair after TON.

Ethnopharmacological relevance: Australian Indigenous medicinal plants represent a valuable yet underexplored source of bioactive compounds with potential therapeutic relevance. The Iningai community of Central Queensland has traditionally used native plants to manage conditions associated with inflammation, pain, infection, and general illness. Scientific evaluation of these plants may provide evidence for their customary applications and identify bioactivities relevant to anticancer biodiscovery. Aim of the study: This study evaluated leaf and stem extracts of seven medicinal plants-Pittosporum angustifolium, Alphitonia excelsa, Calytrix microcoma, Geijera parviflora, Melaleuca uncinata, Gossypium australe, and Eucalyptus similis-traditionally used by the Iningai community, focusing on three biological processes relevant to cancer: oxidative stress, inflammation, and cellular proliferation. Materials and methods: Antioxidant activity was assessed using DPPH radical-scavenging and ferric reducing antioxidant power (FRAP) assays. Anti-inflammatory activity was evaluated in lipopolysaccharide (LPS)-stimulated THP-1 macrophage-like cells by profiling IFN-, TNF-, IL-6, IL-12, IL-18, and IL-23. Antiproliferative activity was assessed using MTT-based viability assays in human and murine liver cancer cell lines (Huh7, Hep3B, Hep-55.1c, and A52). Results: The extracts exhibited distinct biological activity profiles. G. parviflora stem and C. microcoma leaf extracts showed the strongest antioxidant activities, whereas P. angustifolium stem exhibited the weakest radical-scavenging capacity. Cytokine responses were extract-specific, with E. similis leaf extract demonstrating broad and pronounced suppression of multiple LPS-induced pro-inflammatory cytokines. Several extracts produced concentration-dependent reductions in liver cancer cell viability, with P. angustifolium stem exhibiting the most consistent and potent antiproliferative activity across the cell lines tested. Notably, strong antioxidant or anti-inflammatory activity did not necessarily correspond with antiproliferative activity. Conclusion: Australian Indigenous medicinal plant extracts demonstrated distinct antioxidant, immunomodulatory, and antiproliferative activities rather than uniform bioactivity across experimental systems. The divergent activities of G. parviflora, C. microcoma, E. similis, and P. angustifolium highlight the importance of integrated biological screening and support the value of Indigenous knowledge-guided biodiscovery. These plants represent promising sources for further investigation of selective bioactive compounds with potential relevance to anticancer drug discovery.

PurposeHigh dietary fibre intake has been linked to lower cancer risk, yet its role in prostate cancer treatment responses and radiotherapy tolerance remains unclear. We evaluated the effects of dietary fibres (inulin, pectin, {beta}-glucan) on prostate tumour growth, gut microbiota and intestinal response to ionising radiation (IR) in murine models. MethodsMale FVB and C57BL/6J mice were injected with murine Myc-CaP (FVB), RM-1 or DVL3 (C57BL/6J) prostate tumour cells and fed a low-fibre (0.2% cellulose) or high-fibre diet (10% inulin, pectin or {beta}-glucan). Some mice had tumour irradiation (6 Gy). Tumour volume, caecal weight and faecal microbiota relative abundance (by 16S rRNA gene sequencing) were analysed. Caecal contents fermentation acids were quantified by gas chromatography. The effects of dietary fibre on intestinal acute normal tissue toxicity post-irradiation (10-14 Gy) were assessed by intestinal crypt assay. ResultsInulin delayed average tumour growth in all models. Inulin and {beta}-glucan prolonged post-IR tumour control versus 0.2% cellulose (all p <0.05), in some but not all mice. Inulin, pectin and {beta}-glucan increased faecal acetate concentrations post-IR and mice demonstrated responder (R) vs non-responder (NR) phenotypes to diet/IR, associated with Bifidobacterium (inulin-R), Lactobacillus and Parasutterella (pectin-R) and Muribaculacaeae and Muribaculum ({beta}-glucan-R). High fibre-fed mice had enhanced intestinal crypt regeneration following 12 Gy compared to 0.2% cellulose-fed mice. ConclusionsHigh fibre diets slowed prostate tumour growth both alone and following 6 Gy IR, while protecting small intestines from radiation-induced injury. Effects may have been mediated via increased microbiota-driven metabolite production and enhanced epithelial regeneration, but more mechanistic work is required to explore causality. The differences in individual responses to various fibres should be investigated further, as this may have relevance to adopting dietary fibre supplementation strategies in human radiotherapy patients, and may reflect the recognised importance of an individuals baseline microbiota on dietary effects.

Cone photoreceptors are essential for daylight vision, and their degeneration has more profound visual consequences than rod loss in retinal degenerative diseases. Metabolic dysfunction is closely associated with cone degeneration, however the relatively small population of cones in mice and humans have limited our understanding of cone-specific metabolism. Here, we leveraged cone-dominant and cone-degeneration mouse models including Nrl-/-, Cnga3-/-, and high-dose Triiodothyronine (T3) treatment to investigate cone-specific metabolism and their metabolic impacts on the retinal pigment epithelium (RPE). Across models, cone-dominant retinas consistently showed lower pyruvate abundance alongside increases in glutathione, purines, pentose phosphate pathway intermediates, and one-carbon metabolites. Increases in several key amino acids were also associated with higher cone abundance, such as proline, arginine, alanine, valine, leucine, and hypotaurine. Strikingly, aminoadipate, an intermediate in lysine catabolism, was the most robustly changed metabolite in the retina, showing highly consistent increases across models. Relative cone increases were also associated with metabolic changes in the RPE/choroid. Like the retina, RPE/choroids showed consistent increases in aminoadipate, proline, and hypotaurine, as well as xanthosine and betaine, alongside decreases in uracil. Moreover, proteomic analysis of Nrl-/- mice showed decreases in many key metabolite transporters in the RPE/choroid, including carriers for glucose, lactate, aspartate, glutamate, serine, lysine, taurine, and proline. Collectively, these findings further our understanding of cone-specific metabolism and highlight potential cone-specific metabolic vulnerabilities in retinal degeneration.

Esophageal adenocarcinoma (EAC) has a poor five-year survival rate and one of the fastest-rising incidences of any cancer. The presence of dysplasia in Barrett's esophagus (BE) is the main risk factor for EAC development and guides clinical management. Unfortunately, the current histopathological diagnosis of dysplasia is unreliable, with poor inter-observer agreement, highlighting the need for novel biomarkers that can improve diagnostic accuracy. Here, we performed transcriptome profiling across the full spectrum of BE-related neoplasia in 85 samples to delineate gene expression alterations in progressively worse disease stages and identify biomarkers that could complement histopathology to improve the detection of dysplasia and EAC in endoscopic biopsy specimens. Differential gene expression and pathway analyses revealed that the most extensive transcriptional changes occurred during the transition from normal squamous (NSq) to non-dysplastic BE (NDBE), consistent with metaplastic transformation. Compared to NDBE, dysplasia was characterized by enhanced cellular growth and proliferation; upregulation of immune processes and oncogenic signaling pathways were present in EAC. Using machine learning approaches, we identified a novel five-gene panel suitable for a potential RNAseq-based diagnostic test (SLC11A1, IL36A, LUCAT1, MIR215, RNU6-954P) and performed an initial validation of this signature in an additional 51 samples. We also identified several potential novel immunohistochemical markers that may warrant further evaluation, including TREM1, CXCL5, OSM, and motilin. In summary, by delineating transcriptional changes across the full disease spectrum, this study identifies several candidate biomarkers for improving current diagnostic methods for Barrett's dysplasia and EAC.

Microplicae are ridge-like membrane projections that are prominent features of many epithelial surfaces, yet little is known about the principles governing their spatial organisation. Determining whether microplicae represent stochastic membrane folds or biologically organised surface architectures is essential for understanding their formation and functional roles. Here, differential interference contrast images of human buccal epithelial cells were analysed using quantitative image-processing approaches. Ridge networks were segmented and characterised using complementary measurements of characteristic wavelength, including medial-axis and nearest-neighbour Voronoi analyses, together with skeleton-based metrics describing network architecture. Analysis of n=100 buccal epithelial cells sampled from n=10 donors revealed a reproducible sub-micron characteristic wavelength. Mean medial-axis spacing was 0.511 {+/-} 0.042 {micro}m and mean Voronoi nearest-neighbour spacing was 0.588 {+/-} 0.057 {micro}m. Characteristic wavelength exhibited CV of between only 8.26% and 9.67% across the dataset. However, metrics describing network architecture, including ridge density, branching and connectivity, varied by up to 109%. Donor-level analysis reported the same overall trends, with conservation of the characteristic wavelength while network parameters had considerably greater variation. These findings identify a previously unrecognised organising principle of microplical architecture, suggesting that epithelial membrane organisation is regulated through conservation of an intrinsic geometric length scale while network topology remains comparatively free to remodel.

BackgroundChronic obstructive pulmonary disease, primarily caused by exposure to cigarette smoke, is a heterogeneous lung condition characterized by complex metabolic alterations. The metabolic changes associated with smoking status have not been thoroughly investigated. Our study aims to explore the metabolite profile of COPD patients categorised by their smoking habits, including smokers, ex-smokers, and non-smokers. MethodsIn this study, the plasma metabolome of smoking stratified COPD patients were assessed using gas chromatography coupled to mass spectrometry. We applied multivariate and univariate statistical analysis to identify the differentially abundant metabolites. ResultsWe identified 23 altered metabolites in the smokers and 36 in the ex-smokers COPD subgroups. Interestingly, in comparison to the control group, no significant alteration was observed in the plasma of non-smoker COPD patients. Additionally, pathway enrichment analysis revealed top dysregulated metabolic pathways, including biosynthesis of unsaturated fatty acids, galactose metabolism, phenylalanine, tyrosine, and tryptophan biosynthesis, and glycosylphosphatidylinositol (GPI)-anchor biosynthesis. The receiver operating characteristic curve screened five metabolites, such as tetradecanoic acid, 2,4-di-tert-butylphenol, chloroxylenol, tetradecanal, and 1-dodecene, with the highest diagnostic performance (AUC > 0.8). ConclusionThis study reveals distinct plasma metabolic signatures across COPD subgroups categorized by cigarette smoking history.

The long non-coding RNA Negative Regulator of Antiviral Response (NRAV) is known to suppress antiviral immunity by regulating interferon response, but its functional role in tumor immunology remains poorly understood. We examined the relevance of NRAV in melanoma and found that high NRAV expression was associated with poor survival, reduced inflammatory pathway activation, and resistance to immune checkpoint blockade. Bulk and single-cell transcriptomic profiling indicates that NRAV expression is selectively enriched in malignant cells suggesting a potential cancer cell-intrinsic function. To examine whether NRAV can regulate inflammatory responses in melanoma cells, we manipulated the levels of NRAV in the BRAF-mutant A375 melanoma model and characterized the expression of key interferon-stimulated genes (ISGs) following type-I and type-II interferon stimulation. Our findings reveal that the stable NRAV overexpression blunts the induction of key ISGs, whereas NRAV knockdown reciprocally amplifies their transcription. Subcellular fractionation revealed that NRAV is predominantly localized to the nuclear compartment of melanoma cells and the overexpression of NRAV altered regulatory histone marks on the target ISG promoters including MX1 and IFITM3. Collectively, these findings establish NRAV as a tumor-intrinsic epigenetic regulator of interferon signaling, highlighting its potential contribution to melanoma immune evasion.