Experimental Dermatology

BackgroundNon-segmental vitiligo(NSV) shows marked heterogeneity in activity, progression, and treatment response. Reliable clinical markers that predict prognosis and patient-reported outcomes are lacking. ObjectivesTo identify clinicodemographic and clinical predictors of disease extent, progression, repigmentation, treatment dependency, noticeability, and psychosocial impact in NSV. MethodsIn this prospective cohort study, 275 patients with NSV were followed for 12 months. Sixteen baseline variables, including demographic features, autoimmune history, and clinical markers (koebnerization, confetti and trichrome patterns, leukotrichia, mucosal, acral, and periorificial involvement), were recorded. Outcomes included body surface area(BSA), progression, repigmentation, treatment dependency, Vitiligo Noticeability Scale(VNS), and quality-of-life indices(VIS-22, DLQI, C-DLQI, F-VIS). Multivariable analyses and cluster analysis were performed at 6 and 12 months. ResultsMarkers of disease activity leukotrichia, trichrome and confetti lesions, koebnerization, and mucosal, acral, and periorificial involvement were strongly associated with greater BSA, poor repigmentation, higher noticeability, and treatment dependency. Leukotrichia was consistent predictor of poor repigmentation and high VNS. Family history of autoimmunity predicted progression and treatment dependency. Early-onset vitiligo showed lower disease extent but greater family-related psychosocial burden. Cluster analysis identified severe, intermediate, and mild phenotypes with distinct therapeutic responses. ConclusionsSimple clinical markers can stratify NSV patients into prognostic subgroups, enabling individualized treatment and counseling. Plain Language SummaryVitiligo behave variably in different people, some people may have slow-spreading course, while others develop widespread or persistent patches. In this study, we followed 275 people with non-segmental vitiligo for one year to find signs on the skin that could predict how the disease would behave and how it would affect daily life. We found that features such as white hair within patches (leukotrichia), speckled (confetti) or three-colored lesions (trichrome), new patches appearing after injury (koebnerization), and involvement of the lips, mouth, hands, feet were linked to more severe disease, poorer response to treatment, and greater cosmetic concern. A family history of autoimmune disease increased the risk of worsening vitiligo. Patients who developed vitiligo early in life had less skin involvement but greater emotional and family-related impact. These easily recognized signs can help doctors and patients plan treatment and set realistic expectations. Significance of the studyNon-segmental vitiligo (NSV) has a heterogeneous and unpredictable clinical course with variable progression and response to therapy. However, robust prospective data linking these markers with long-term outcomes and patient-reported measures remain limited. In our prospective cohort of 275 patients, clinical markers such as leukotrichia, trichrome and confetti lesions, koebnerization, and acral/mucosal/periorificial involvement, were strongly associated with greater disease extent, poorer repigmentation, higher treatment dependency, and increased noticeability. Leukotrichia consistently predicted poor repigmentation. Thereby, prognostic stratification can also improve patient counselling regarding expected repigmentation, treatment duration, and psychosocial burden.

BACKGROUND Erythema nodosum leprosum (ENL) is a severe inflammatory complication of leprosy associated with disability, morbidity and mortality. Impairment of health-related quality of life (HRQoL) in ENL has been reported using the Dermatology Life Quality Index (DLQI) and the 36-Item Short Form Health Survey (SF-36), the latter validated in people affected by leprosy. Understanding the correlation between these measures is important to determine whether the shorter dermatology-specific DLQI provides a valid and practical measure of HRQoL in ENL. OBJECTIVES To examine the relationship between DLQI and SF-36 scores in individuals with ENL using data from the Methotrexate and Prednisolone study in ENL (MaPs in ENL). METHODS A post-hoc analysis of prospectively collected HRQoL data from the trial sites in India, Indonesia, and Nepal of the MaPs in ENL multicentre randomised clinical trial was performed. HRQoL was assessed using the DLQI and SF-36 at enrolment and at weeks 24, 48 and 60. Associations between DLQI and SF-36 physical (PCS) and mental (MCS) component summary scores were evaluated using correlation analyses and multivariable linear regression at enrolment, and linear mixed-effects models during follow-up adjusted for age, sex, recruiting centre and enrolment SF-36 scores. RESULTS A total of 383 paired HRQoL assessments from 129 participants were analysed. At enrolment, HRQoL impairment was substantial (median DLQI 19, IQR 15-21; mean PCS 30.3 + - 7.3; mean MCS 33.3 + - 8.4). DLQI scores improved markedly during follow-up. Across all timepoints, DLQI was strongly inversely correlated with PCS and MCS (both p<0.001). In adjusted analyses, higher DLQI scores were consistently associated with lower PCS and MCS. At enrolment, each 1-point increase in DLQI was associated with a 0.66-point reduction in PCS and a 0.51-point reduction in MCS (both p<0.001). These associations remained strong during follow-up, with no evidence that they varied over time. CONCLUSIONS DLQI scores were strongly and consistently associated with SF-36 physical and mental health scores. These findings support the use of the DLQI as a practical patient reported outcome measure to assess the HRQoL associated with ENL and its change following treatment.

Hidradenitis suppurativa (HS) is a chronic, debilitating, inflammatory skin disorder. Medications have been reported in association with cases of new-onset HS or exacerbation of existing disease; however, the extent of this risk is unclear. We queried the FDA adverse event reporting system (FAERS) from 2003-2023 to identify drug-specific reporting signals for HS. We stratified reports by whether HS was listed as an indication (Drug-Worsened, DW) or not (Drug-Induced, DI) to distinguish disease flares from de novo disease. Primary suspect drugs with > 3 HS reports were included. Disproportionality was quantified using reporting odds ratio (ROR) with Wald 95% confidence intervals (CI). Time-to-onset was also evaluated. We identified 5,529 HS reports: 3,725 DW and 1,804 DI. Females comprised 63% (mean age 41) and the US was the top reporting country (81.8% DW; 53.66% DI). In the DI group, statistically significant signals were observed for immunomodulators also used to treat HS including adalimumab (n=506, ROR= 12.6 [11.3-14.0]) infliximab (n=108, ROR=8.2 [6.7-10.0]), and secukinumab (n=79, ROR=6.6 [5.2-8.2]), consistent with paradoxical reactions. Median time-to-onset was 22 days for secukinumab, compared to 312 and 319 days for adalimumab and infliximab. Signals were also identified for isotretinoin (n=28, ROR= 6.2 [4.2-8.9]), and for antineoplastic agents including cytarabine (n=25, ROR= 24.7 [16.6-36.6]) and omacetaxine (n=8; ROR= 7416 [CI 2923-18816]), which may reflect reported eccrine hidradenitis. In the DW group, adalimumab (n=2967), secukinumab (n=67), and infliximab (n=57) predominated but displayed lower RORs (0.72-1.4), likely reflecting indication bias. While mechanisms of drug-associated HS require further clarification, our findings demonstrate significant associations and highlight the importance of dermatologic monitoring when initiating certain agents.

Background: Microbiota dysbiosis of the skin has been implicated in ulcer formation. Individuals with diabetes remain at high risk for diabetic foot ulcers (DFUs) even after ulcer healing. Topical chlorhexidine gluconate (CHG) is a broad-spectrum antiseptic commonly used to reduce microbial burden. In a prior randomized clinical trial comparing daily CHG foot treatment with soap-and-water treatment, no statistically significant reduction in new DFUs was observed, prompting evaluation of whether CHG produced durable changes in the skin microbiota. Objective: To compare changes in foot skin microbiota (including bacterial bioburden, diversity, and community composition) associated with daily CHG versus soap-and-water use over one year in people with diabetes and prior foot complications. Methods: In a single-center, double-blind, placebo-controlled randomized trial, 87 participants were randomized to daily CHG wipes or soap-and-water wipes for 12 months. Foot swabs were collected at baseline, 3 and 12 months, and 4 weeks post-treatment. Bacterial bioburden was quantified. Microbiota composition was assessed using 16S rRNA and ITS amplicon sequencing. Key Results: CHG treatment significantly reduced bacterial bioburden, increased microbial diversity, and altered community composition, including sustained reductions in Staphylococcus abundance. Several microbiota changes persisted more than 4 weeks after treatment cessation. Soap-and-water treatment showed similar but smaller and largely nonsignificant trends. Conclusions: Daily CHG use durably modifies foot skin microbiota in high-risk individuals with diabetes. However, this alone may be insufficient to prevent new foot complications, highlighting the need for additional interventions. These findings have implications for long-term CHG use in populations at risk for staphylococcal infections.

BackgroundSkin is constantly exposed to mechanical forces such as pressure and friction, which need to be sensed and buffered to ensure tissue homeostasis and barrier function. Desmosomes are essential for epidermal integrity, but their role in converting mechanical cues into cellular signaling responses are not well understood. MethodsHere, we combine proteomics and shear-stress assays with live-cell reporters to investigate how desmosomes modulate stress-kinase pathways in keratinocytes. ResultsWe show that the desmosomal adhesion molecule DSG3 is essential not only for cell-cell adhesion but also for modulating p38MAPK and ERK signaling. Loss of DSG3 disrupts mechanotransduction-related protein networks, including the expression of the mechanosensitive channel Piezo1. Under static conditions, DSG3 dampens ERK activity via Piezo1-dependent mechanisms, whereas DSG3 suppresses p38MAPK activity through an independent mechanism. In contrast, DSG3 is required to trigger an activation of both ERK and p38MAPK in response to shear stress in a Piezo1-dependent manner. Experiments with domain-specific DSG3 mutants demonstrate that cell cohesion and signaling responses are partially uncoupled, while maintaining DSG3 tail integrity was crucial for p38MAPK and ERK responses. ConclusionThese findings demonstrate that DSG3 independently coordinates adhesion and mechanotransduction in a domain-specific manner, providing novel insights into how DSG3 contributes to epithelial integrity under dynamic mechanical environments.

BackgroundSkin aging is multifactorial, and finished multi-ingredient oral beauty supplements require dedicated clinical evaluation because their effects cannot be inferred from individual ingredient data alone. ObjectiveTo explore, in a 56-day single-arm open-label study, whether daily oral intake of NatureU(R) Mind Care BeautyU Caps is associated with within-participant changes in crows-feet wrinkle count (primary endpoint), stratum corneum hydration (secondary endpoint), and additional exploratory skin-aging parameters in adult women. MethodsA single-center, open-label, single-arm exploratory study enrolled 33 healthy women aged 36-56 years; 31 completed the protocol and were included in the completer efficacy analysis. Participants took one capsule orally once daily for 56 consecutive days. Assessments were performed at D0, D28 and D56 using PRIMOS CR, Corneometer CM 825, Cutometer MPA580, Glossymeter, Colorimeter CL400, Mexameter MX18, VISIA CR, DermaScan and a structured self-assessment. ResultsPRIMOS CR crows-feet wrinkle count fell from 965 {+/-} 334 at D0 to 514 {+/-} 171 at D56 (within-participant change -46.74%; nominal P = 0.001). Corneometer hydration rose from 44.3 {+/-} 7.8 to 70.3 {+/-} 9.9 (+58.69%; nominal P = 0.001). Exploratory parameters (other wrinkle metrics, elasticity, gloss, ITA{degrees}, melanin, spots, dermal thickness/density) generally moved in directions consistent with the primary signal. No adverse reactions were reported. ConclusionIn this open-label, single-arm exploratory study, daily NatureU(R) Mind Care BeautyU Caps was associated with within-participant reductions in crows-feet wrinkle count and increases in stratum corneum hydration over 56 days. Findings are hypothesis-generating; randomized placebo-controlled trials are required.

Hailey-Hailey disease (HHD) is a genetic skin blistering disorder lacking approved treatments despite linkage to ATP2C1 variants 25 years ago. Since knockout mice did not replicate HHD, we ablated ATP2C1 in human keratinocytes or chemically inhibited its encoded Golgi calcium pump SPCA1. In organotypic epidermis, SPCA1 deficiency or inhibition reproduced HHD pathology, disrupting desmosomal cadherins and severing cell-cell junctions, termed acantholysis. RNA sequencing of heterozygous cells identified dysregulation of actin and Rho GTPases along with EGF receptor signaling as potential pathogenic drivers. Accordingly, SPCA1-depleted organotypic epidermis and HHD biopsies exhibited cortical actin disorganization and hyper-phosphorylation of the Rho kinase (ROCK) target, myosin light chain. Rho activation was sufficient to induce acantholysis, while ROCK inhibition partially restored heterozygous keratinocyte cohesion. A fluorescent biosensor demonstrated ERK hyper-activation in heterozygous cells along with desmosomal cadherin mis-localization. Importantly, treating SPCA1-deficient keratinocyte sheets with MEK and ROCK inhibitors together fully restored their integrity. Our results show HHD blistering is driven by desmosome and cortical actin dysfunction that was mitigated by targeting MEK and ROCK with repurposed drugs, offering a viable treatment strategy. Moreover, our model provides a blueprint for replicating genetic epidermal disorders to delineate pathogenic mechanisms and vet therapeutics for other orphan skin diseases. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/726679v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@b2de6aorg.highwire.dtl.DTLVardef@128411borg.highwire.dtl.DTLVardef@1ca760forg.highwire.dtl.DTLVardef@10cd6c7_HPS_FORMAT_FIGEXP M_FIG C_FIG

Palmoplantar pustulosis (PPP) and dyshidrotic eczema (DE) are chronic vesiculopustular dermatoses with overlapping clinical presentations but distinct underlying biology. Although comparative transcriptomic and proteomic analyses between PPP and DE have been reported, they remain limited in number and scope, with no comprehensive understanding of their distinct molecular signatures. Moreover, their molecular mechanisms remain unclear, and currently available therapeutic options are limited. To clarify disease-specific epidermal programs underlying vesicle formation, we conducted Visium HD spatial transcriptomic analysis of FFPE lesional skin samples obtained from patients with PPP and DE, followed by immunohistochemical validation against normal palmoplantar skin controls. Spatial clustering identified a keratinocyte subpopulation adjacent to vesicles that exhibited distinct transcriptional programs in the two diseases. In PPP, vesicle-associated keratinocytes demonstrated marked downregulation of aquaporin-3 (AQP3) and E-cadherin, together with strong, spatially localized activation of JAK-STAT3 signaling. Conversely, DE exhibited diffuse AQP3 expression and more homogeneous activation of JAK-STAT3 signaling throughout the epidermis. These results indicate that, although PPP and DE share inflammatory pathways, they differ substantially in their spatial molecular architecture. Reduced AQP3 expression and localized STAT3 activation may contribute to vesicle formation in PPP, supporting our previous hypothesis that implicates intraepidermal sweat leakage as a pathogenic mechanism in PPP. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/723901v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@19c7591org.highwire.dtl.DTLVardef@eab29aorg.highwire.dtl.DTLVardef@73c2e2org.highwire.dtl.DTLVardef@1ffc02f_HPS_FORMAT_FIGEXP M_FIG C_FIG

Unlike the conventional mature neutrophils, immature neutrophils have been investigated for their regenerative properties; however, their limited availability necessitates alternative generation strategies. Here, we used a combination of dimethylsulfoxide (DMSO) and 1,25-dihydroxyvitamin D3 (D3) to differentiate myeloid leukemia (HL-60) cells into immature neutrophil-like cells. Differentiated cells exhibited reduced cell size, loss of uniformity, decreased nuclear-to-cytoplasmic ratio, band-shaped nuclei, increased proportion of CD11b+CD14+ cells (indicative of immature neutrophils), decreased proportion of CD11b+CD16+ cells (indicative of mature neutrophils), higher levels of arginase 1, TGF{beta}1 (markers of immature neutrophils), and no expression of CD16, MRC1 (markers of mature neutrophils and M2 macrophages, respectively). Proteomic analysis revealed enrichment of proteins associated with immature neutrophils and wound healing. Functionally, these cells supported limbal stem cell growth and wound closure in vitro, indicating relevance for corneal regeneration. Administration of these cells to ex-vivo and in-vivo alkali-injured corneas, resulted in significant effect on promotion of wound healing, with epithelial regeneration and decreased fibrotic markers, proving that such cells hold promise for clinical translation as a therapeutic tool for tissue repair.

Atopic dermatitis (AD) is a highly prevalent, relapse-remitting, inflammatory skin disease, the hallmark symptom of which is chronic itch. Mechanisms underlying AD itch are multifactorial, involving various cells, receptors, and mediators. Developing a physiologically relevant, human model system for AD itch research and drug development is crucial. To this end, human induced pluripotent stem cell-derived sensory neurons (iPSCSNs) were cultured with human primary keratinocytes to form deconstructed skin models. Using Ca2+-imaging in a direct contact, 2.5D co-culturing format, which mimics natural skin innervation and permits both paracrine exchange and juxtacrine signaling, iPSCSNs exhibited functional TRPA1 responses not seen in monotypic iPSCSN cultures or in iPSCSNs conditioned with keratinocyte medium. Different AD-associated cytokines were used to stimulate the co-culture systems to mimic an inflamed lesional skin environment, whereby TNF was found to increase iPSCSN chemosensitivity. Finally, both TRPA1 and JAK1/2 inhibition reduced iPSCSN responses to pruritogens (TSLP, IL-31), thus supporting TRPA1 as a therapeutic target for AD itch in humans. This study demonstrates that human deconstructed skin models can be a useful tool in AD and broader pruritus research. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/724000v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@11c0c9borg.highwire.dtl.DTLVardef@7fa518org.highwire.dtl.DTLVardef@2fe7a2org.highwire.dtl.DTLVardef@1105fa7_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundPhenome-wide association studies (PheWAS) can reveal novel associations between variants in drug-target genes and disease and, as such, can be used to predict new drug-indication pairs for repurposing drugs with a known mechanism of action. A platelet-derived growth factor receptor beta (PDGFR{beta}) PheWAS demonstrated that patients with a single nucleotide variant that reduces PDGFR{beta} expression exhibit a higher prevalence of chronic skin ulcers, skin grafts, and reconstructive surgeries. Recombinant human platelet derived growth factor BB (rhPDGF) is a therapeutic that binds to and activates PDGFR{beta} and has received FDA approval for multiple indications, including improving healing of lower extremity diabetic neuropathic ulcers, augmenting periodontal bone and soft tissue reconstruction, and stimulating orthopedic bone regeneration. Leveraging a drug-repurposing methodology informed by PheWAS, we hypothesize that rhPDGF will provide therapeutic benefit in the treatment of other complex wounds, like full-thickness surgical wounds of the head or neck that cannot heal by primary intention following skin cancer excision. MethodsThis prospective, double-blinded, single-site study aims to enroll 40 participants, randomized at a ratio of 1:1, comparing the efficacy of an advanced wound matrix saturated with rhPDGF or saline. Comparisons will be stratified by anatomical location (scalp/forehead versus face/neck) and maximum surgical defect dimensions (< 3cm versus > 3cm). The primary outcome of this study will evaluate the time in days to 81-100% granulation of the wound bed by expert clinical assessment of daily photographs. Secondary outcomes will assess the superiority of the rhPDGF-enhanced wound matrix relative to control with respect to wound granulation rate, epithelialization, complete wound healing, and patient reported outcomes (PROMs). DiscussionAlthough reconstructive techniques are available for healing complex head and neck wounds following skin cancer excision, these procedures are invasive, and older, frail patients are often suboptimal candidates. There remains a need for less invasive therapeutic approaches that reduce the healing time and mitigate the morbidity associated with chronic wounds. A PheWAS analysis identified complex wounds requiring reconstructive surgery as a novel drug-indication pair for repurposing rhPDGF. This protocol is designed to evaluate the efficacy of an rhPDGF-enhanced advanced wound matrix for healing complex head and neck wounds post skin cancer excision that cannot heal by primary intention. Clinical trial registrationThis trial is registered at ClinicalTrials.gov (NCT06634030).

Accurate risk stratification of pigmented skin lesions is critical for early melanoma detection and for reducing unnecessary excisions. Artificial intelligence (AI) is increasingly applied to dermoscopic image analysis, but its diagnostic performance relative to standard dermoscopy in real-world clinical settings remains uncertain. To address this gap, we conducted a systematic review and meta-analysis of prospective clinical studies directly comparing AI alone, dermoscopy, and AI-assisted clinicians for malignancy risk assessment of pigmented skin lesions. We systematically searched PubMed, Embase, Web of Science, and Cochrane Library from inception to January 2026. Ten studies with 17 diagnostic arms (10 dermoscopy arms, 6 AI-alone arms, and 1 AI-assisted clinician arm) were included. Pooled sensitivity and specificity were 0.773 (95% CI, 0.648-0.863) and 0.793 (95% CI, 0.673-0.877) for dermoscopy, and 0.757 (95% CI, 0.428-0.928) and 0.859 (95% CI, 0.619-0.958) for standalone AI. Summary ROC curves showed overlapping performance, indicating that autonomous AI is broadly comparable to dermoscopy but does not demonstrate a consistent advantage. Heterogeneity in AI performance was driven almost entirely by threshold effects rather than by differences in inherent model capacity. AI-assisted clinicians showed promising results (sensitivity 1.000, specificity 0.837) in a single study, but more evidence is needed. Our findings suggest that, at present, AI should be viewed as a complementary decision-support tool rather than a replacement for dermoscopic evaluation. The study provides valuable evidence for clinicians, guideline developers, and researchers working on AI integration into melanoma diagnostic pathways.

Psoriasis is a chronic inflammatory skin disease characterized by keratinocyte hyperproliferation and immune dysregulation. Emerging clinical and experimental evidence suggests that endogenous lipid (endolipid) signaling systems, including the endocannabinoid system (ECS), represent a promising therapeutic target to treat psoriasis; however, comprehensive characterization of small-molecule endolipids and related proteins in psoriatic skin and their relationship to systemic changes remains limited. Here, we used the imiquimod (IMQ)-induced mouse model of psoriasis to perform combined lipidomic and transcriptional profiling of endolipid signaling in both skin and plasma. Targeted lipidomics revealed a striking divergence between tissues: most endolipids increased in inflamed skin but decreased in plasma, including the canonical ECS lipids anandamide and 2-arachidonoylglycerol. In contrast, selected lipid species, including taurine-conjugated metabolites (both N-acyl taurines and bile acids), were elevated in both tissues, indicating pathway-specific regulation. Targeted transcriptional analysis of whole skin showed reduced expression of key endolipid biosynthetic enzymes (Napepld, Dagla, Daglb) and the cannabinoid receptor Cnr1, while Cnr2 and ECS-related metabolic enzymes remained unchanged. Additional alterations were observed in transcripts involved in related endolipid signaling (Trpv1, Trpv4, Ppara, Pparg, Gpr55), bile acid metabolism (Fxr, Bsep, Fabp4, Fabp5, Cyp27a1, Cyp8b1), and inflammatory pathways (Cox-2). To resolve this apparent discrepancy between lipid levels and gene expression, we performed compartment-specific analyses of epidermal and dermal layers. These revealed a predominantly suppressive epidermal response across multiple ECS-related proteins, contrasted by a more variable dermal profile with selective preservation or upregulation, particularly of Cnr2. Together, these findings demonstrate that psoriasiform inflammation is associated with compartment-specific remodeling of endolipid signaling across skin and systemic compartments, underscoring the functional heterogeneity of epidermal and dermal layers. This dataset provides novel insights into the dysregulation of endolipid signaling systems in psoriasis and provides a foundation for the development of spatially informed, lipid-based therapeutic strategies.

UT-018, a stem cell chemoattractant formulation, demonstrated significant regenerative activity across independent murine wound-healing and hair-regeneration studies. Topical treatment accelerated wound closure, enhanced granulation tissue formation, improved collagen organization, increased fibroblast proliferation, and enhanced dermal vascularization. Separate hair-growth studies demonstrated increased follicular density, deeper follicular penetration, enhanced dermal vascularization, and induction of anagen-phase transition by UT-018. Mechanistic studies demonstrated strong intracellular cAMP generation and activation-associated {beta}-catenin phosphorylation consistent with GPCR-mediated regenerative signaling.

Oxidative stress is proposed to be a driver of age-related diseases. Age-related macular degeneration is one such disease, where the retinal pigment epithelium (RPE) is affected early in the disease. Vasculature damage also occurs, sometimes preceding RPE damage. To model some aspects of dry AMD, we used the NaIO3 mouse model of oxidative damage. Disruption of the deep retinal vascular plexus, disorganization and death of capillaries within the choriocapillaris, and marked electroretinographic decline were observed. AAV overexpressing the transcription factor, NRF2, which induces anti-oxidation enzymes and represses inflammation, was tested for protection of damage. The BEST1 promoter limited expression to the RPE. The RPE, photoreceptors, and vascular architecture in both retinal and choroidal compartments were protected. Conditioned medium from RPE-choroid explants, infected by AAV8/BEST1-NRF2, was sufficient to transfer partial protection in vivo, indicating that NRF2 induces a protective secreted factor(s). Analysis of RNA-seq data identified growth differentiation factor 15 (GDF15) as a candidate downstream mediator. Injection of recombinant GDF15 reproduced key protective phenotypes in vivo, whereas Gdf15-deficiency attenuated NRF2-mediated rescue. Pharmacologic inhibition of TGF-{beta} receptor signaling diminished NRF2 associated protection, supporting involvement of this signaling pathway. In a laser-induced choroidal neovascularization model, intravitreal GDF15 injection reduced fluorescein leakage and lesion size. These findings support a model in which NRF2 activation in the RPE induces expression of GDF15, which is capable of protecting the RPE, photoreceptors, and the retinal and choroidal vasculature. NRF2 and GDF15 have therapeutic potential for ocular diseases, as well as for other diseases with vascular pathology.

Cutaneous squamous cell carcinoma (cSCC) is a common skin cancer associated with substantial morbidity and mortality in advanced stages. Despite its well-described stepwise progression from actinic keratosis to invasive disease, robust molecular markers for stage discrimination and clinical decision-making remain limited. We sought to define the transcriptional continuum underlying cSCC progression, identify stage-associated biomarkers, and assess the broader relevance of these programs across human malignancies. Bulk RNA sequencing (HTG EdgeSeq) and spatial transcriptomics (GeoMx) were performed on biopsies from eight patients, each presenting multiple disease stages (healthy skin, premalignant lesion, tumor core, and invasive front) within the same lesion field, enabling within-patient analysis of progression. Spatial transcriptomic analyses identified more than 2,000 differentially expressed genes whose expression varied across disease stages. These genes were organized into 18 coordinated expression programs reflecting progressive biological rewiring during tumor evolution. Proliferation, extracellular matrix remodeling, inflammation, and stress-response pathways were progressively upregulated, whereas epithelial differentiation and metabolic processes, including lipid and amino acid metabolism, were downregulated. Macrophages exhibited distinct metabolic reprogramming, with increased purine metabolism, glycolysis, and pyruvate metabolism across progression. To evaluate the broader clinical relevance of these progression-associated programs, we developed a reproducible Snakemake pipeline to systematically screen 32 solid and hematologic malignancies from The Cancer Genome Atlas (TCGA). A combined cSCC-progression signature was significantly associated with poor overall survival (P < 0.05) in 10 additional cancer types. Finally, we identified 12 stage-informative biomarkers, whose spatially restricted expression patterns were validated using Visium HD. This study provides a spatially resolved and stage-aware transcriptomic map of cSCC progression, identifies coordinated gene programs underlying disease evolution, and defines progression-associated signatures with prognostic relevance across multiple cancers, highlighting their potential translational value.

BackgroundPrimary and secondary resistance to immune checkpoint blockade (ICB) remains a critical challenge in advanced melanoma. Oncolytic Viruses (OV) selectively lyse tumor cells while generating systemic anti-tumor immune responses with minimal side effects. Yet their clinical use is limited to refractory melanoma patients and are only given in combination with second-line ICB regimens. ICB can both help and hinder OV efficacy depending on the source of checkpoint interactions across the tumor-immune microenvironment (TiME). However, functional checkpoint interactions are typically inferred from gene or protein expression and rarely contextualized within myeloid- and antigen presenting cell-associated immune niches during OV therapy, despite these populations dominating melanoma TiMEs and serving as key regulators of anti-viral immunity. MethodsAn integrated multi-omics framework combining Nanostring GeoMx digital spatial profiling (DSP), COMET sequential immunofluorescence (seqIF) and functional oncology mapping (FuncOmap) was applied to melanoma patient tissues collected pre- and post-neoadjuvant Talimogene Laherparepvec (T-VEC) to characterize immune remodeling and directly quantify checkpoint interaction dynamics associated with pathologic responses to OV therapy. ResultsT-VEC induced broad lymphocyte- and myeloid-associated immune transcriptional activation across melanoma TiMEs; however, pathologic responses could not be defined by bulk transcriptomics or cellular deconvolution alone. COMET seqIF analysis identified that HSV-associated M1/APC-like tumor-associated macrophages (TAMs) were enriched in complete pathologic response (CR) tissues and were a major source of PD-1/PD-L1 interaction niches. While partial (PR) and non-pathologic response (NR) tissues retained melanoma-centered PD-1/PD-L1 interaction niches and were enriched for B cell and M2-like TAM populations. FuncOmap analysis indicated that post-T-VEC PD-1/PD-L1 interaction states were consistently elevated in tumor bed, but not in lymph node tissues, across all pathologic response groups. Suggesting that immune checkpoint interactions may benefit T-VEC therapeutic responses depending on their spatial and immune context relative to OV infection. ConclusionsThese findings highlight the importance of integrated transcriptomic and functional proteomic analyses for resolving the spatial distribution and functional status of immune niches during OV therapy. Resolving PD-1/PD-L1 interaction states to specific M1/APC-like TAM and B cell niches may define mechanisms of responses and resistance to OV therapy.

Basal keratinocytes in the skin are essential for epidermal homeostasis and repair; however, how intrinsic alterations in these cells contribute to inflammatory skin pathology remains poorly understood. In this study, we employed a tamoxifen-inducible mouse model to express the human RUNX1-ETO fusion gene, a well-established oncogenic driver of acute myeloid leukemia, in epidermal basal keratinocytes. RUNX1-ETO induction in keratinocytes resulted in progressive skin inflammation in vivo, accompanied by splenomegaly, epidermal hyperplasia, increased cytokine production, and alterations in epidermal stem cell composition. Inflammatory lesions were prominent in the tail, ear, and plantar epidermis, whereas hair-bearing dorsal skin remained largely unaffected. RNA-seq analysis of FACS-isolated RUNX1-ETO+ basal keratinocytes revealed global changes in gene expression, characterized by the suppression of epidermal homeostatic and metabolic programs and the activation of inflammatory signaling pathways. In particular, RUNX1-ETO expression was associated with increased TNF/NF-{kappa}B and IL-6-STAT signaling, as well as interferon-associated inflammatory pathways, together with the induction of neutrophil-attracting chemokines and epithelial inflammatory mediators. Together, these findings indicate that RUNX1-ETO-mediated transcriptional dysregulation in basal keratinocytes promotes a pro-inflammatory cellular state that drives progressive skin inflammation.

In this study, we evaluated the impact of different in vitro 3D culture modelling methods on the activity of doxorubicin (DOX) and 5-fluorouracil (5-FU) in human melanoma spheroids. Human melanoma A375 and IGR39 spheroids were generated using the hanging drop and non-adhesive surface methods. Spheroid growth dynamics were assessed by measuring changes in spheroid diameter. To compare the effects of anticancer drugs in spheroids of different sizes, spheroids of approximately 200 and 400 {micro}m were formed. Drug activity was evaluated based on spheroid growth and cell viability using the MTT assay. A375 spheroids formed using the non-adhesive surface method were more sensitive to DOX than spheroids formed using the hanging drop method. In smaller A375 spheroids, 10 {micro}M 5-FU reduced cell viability more effectively in spheroids formed using the hanging drop method. In contrast, IGR39 spheroids formed by the hanging drop method were more resistant than those formed on a non-adhesive surface. However, in IGR39 spheroids, the effects of DOX and 5-FU on growth and viability did not significantly differ between formation methods. In conclusion, A375 spheroid growth was not significantly influenced by the formation method, whereas IGR39 spheroid growth depended on the method used. A375 spheroids formed on non-adhesive surfaces were more sensitive to DOX, whereas 5-FU activity depended on drug concentration and spheroid size. In IGR39 spheroids, the effects of DOX and 5-FU on growth and viability were largely independent of the spheroid formation method. Based on these results, it can be concluded that the researchers should carefully select the spheroid formation method for their studies, as this may influence the results of the tested compounds effect on their size and viability.

Background and AimsPlants deploy triterpenoid saponins as chemical defences against herbivores, yet it remains unclear whether insect digestion detoxifies these compounds or generates equally or more active metabolites. Because saponin bioactivity depends strongly on glycosylation patterns, we examined the fate and defensive activity of hederagenin-derived saponins during herbivory. MethodsLarvae of Plutella xylostella were fed leaf discs containing structurally defined hederagenin-derived saponins. Saponin composition in treated leaves and larval frass was analysed by LC- qTOF-ESI-MS/MS. Feeding assays were used to compare the antifeedant activity of mono- and bidesmosidic forms. Key ResultsLarvae selectively metabolized complex hederagenin-derived saponins into simpler forms, with cellobiosides converted into monoglucosides during digestion, resulting in a marked shift in saponin composition between ingested material and frass. Feeding assays showed that monodesmosidic saponins strongly deterrer feeding, whereas bidesmosidic saponins were largely inactive. The loss of activity in bidesmosidic saponins was not explained by differential metabolism, indicating that glycosylation patterns directly determine biological function. ConclusionsInsect herbivores selectively modify saponin structures through deglycosylation, thereby altering their defensive properties. Our findings demonstrate that glycosylation governs both saponin activity and metabolic fate, highlighting insect-driven turnover as a critical component of plant chemical defence during plant-herbivore interactions. Issue SectionOriginal article