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Pigment Cell & Melanoma Research

Wiley

Preprints posted in the last 30 days, ranked by how well they match Pigment Cell & Melanoma Research's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

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Uveal and cutaneous melanoma share a common mutation with distinct prognostic implications: A bioinformatic study

Razmjooei, F.; Ashayeri, H.; Jafarzadeh, Z.; Dabbaghabdollahi, P.; Jafarizadeh, A.

2026-08-11 genetic and genomic medicine 10.64898/2026.08.07.26359988 medRxiv
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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.

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State tanning bed availability is associated with early-onset Melanoma incidence in the Midwest and Southern United States

Graffam, D.; Semprini, J.

2026-08-24 dermatology 10.64898/2026.08.21.26361039 medRxiv
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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.

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A Translational Reference for Green Autofluorescence Imaging in the Rhesus Macaque Eye using the OcuMet Beacon

Ripolles-Garcia, A.; Lim, J.; Raposo, A. C.; Bailey, J. C.; Handel, K. W.; Khan, M. J.; Sutton, L. R.; Yu, J.; Dougherty, E. K.; Nguyen Jaggers, T.; Lam, B.; Valjalo, Y. N.; Thienpaitoon, R.; Muniz, N. A.; Giorgi, E.; Villafuerte-Trisolini, C. I.; Anderson, K.; Habbas-Nimer, N.; Rich, C. A.; Riegger, K.; Moshiri, A.; Leonard, B. C.; Yiu, G.; Thomasy, S. M.

2026-08-19 physiology 10.64898/2026.08.11.744247 medRxiv
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PurposeTo evaluate associations between green autofluorescence (GAF) and structural and functional measures relevant to retinal and optic neuropathies, and to establish normative GAF values across the optic nerve head (ONH), macula, and papillofoveal bundle (PFB) in rhesus macaques. MethodsEighty-two macaques with normal ONH morphology by spectral-domain optical coherence tomography (SD-OCT) were included with a mean {+/-} SD age of 12.76 {+/-} 7.18 (range 0.11-29.39) years. The GAF images were acquired in the ONH, macula and PFB with the OcuMet Beacon. In a subset of macaques (n=19), pattern electroretinogram (PERG) and photopic full-field ERG including the photopic negative response (PhNR) were recorded. ResultsThe GAF significantly increased with age in the ONH, macula and PFB. After adjusting by age, there were no sex differences, but IOP showed a positive association with macular GAF. At the ONH, higher GAF correlated with thinner retinal nerve fiber layer, inner and outer segment complex, and total retinal thickness. In the macula, inner nuclear layer thickness was positively associated with GAF, whereas outer plexiform layer and inner and outer segment complex were inversely associated. The PERG amplitudes inversely tracked ONH GAF. ConclusionsGAF rises with age and IOP, couples to retinal structure, and at the ONH, aligns with inner-retinal functional indices. This study provides a regional reference for GAF in rhesus macaques. Translational RelevanceNormative GAF data in healthy rhesus macaques provide a framework for interpreting this noninvasive signal in translational studies of retinal and optic nerve disease.

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Tripelennamine 1% topical cream versus diphenhydramine 1% topical cream for the relief of histamine-induced itching: A proof-of-concept study in healthy adults.

Nornoo, A. O.; Maarsingh, H.

2026-09-04 dermatology 10.64898/2026.09.01.26361939 medRxiv
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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.

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Perceptions of Equity, Challenges, and Identity-Based Differences Among U.S. Entomologists

Barros Bustos, S. H.; Chicas-Mosier, A.; Abramson, C.

2026-08-24 scientific communication and education 10.64898/2026.08.18.745652 medRxiv
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This study aimed to examine entomologists' perceptions of equity, inclusion, and exclusion within the discipline, identifying perceived challenges and proposed solutions for advancing equity in the field. The present study surveyed 47 self-identified entomologists living in the United States in 2023. Using a mixed-methods design, the study examined entomologists' perceptions of inclusion and exclusion within the discipline through qualitative and quantitative measures. Respondents highlighted needs for race-conscious funding opportunities, comprehensive inclusion efforts through geographically diverse outreach, and access to role models and mentors with similar identities to future entomologists. Findings are discussed in relation to a smaller 2013 study on recruitment and retention of entomologists of color, which offers preliminary historical context. The 2013 respondents emphasized intrinsic and age-based barriers to recruitment (e.g., lack of interest, limited K-12 outreach), the 2023 findings point toward structural inequities and retention needs (e.g., systemic exclusion). The 2013 comparison is interpreted as exploratory given differences in sample size and scope between the two studies. The 2023 study highlights evolving perceptions of persistent inequities in entomology and identifies opportunities to build a more inclusive and representative discipline.

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Ferritinophagy Contributes to Iron Accumulation and Ferroptosis in FuchsEndothelial Corneal Dystrophy

Shepard, Z.; Skeie, J. M.; Shevalye, H.; Eggleston, T.; Li, L.; Field, M.; Schmidt, G.; Phruttiwanichakun, P.; Sales, C.; Salem, A. K.; Greiner, M.

2026-08-10 cell biology 10.64898/2026.08.08.743691 medRxiv
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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.

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Reduced PDE4D expression and activity in Acrodysostosis Type 2 patient fibroblasts underlie disease pathology

Gardner, O. F.; Ling, J.; Munkongcharoen, T.; Kyurkchieva, E.; Leitch, H. G.; Wilson, L. C.; Baillie, G. S.; Ferretti, P.

2026-08-11 cell biology 10.64898/2026.08.10.743905 medRxiv
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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.

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Human buccal epithelial microplicae maintain a characteristic wavelength despite variable network topology

McConnell, G.

2026-08-07 cell biology 10.64898/2026.08.06.743190 medRxiv
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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.

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Tracking Neural, Sensory, and Sensorimotor Adaptation to Progressive Vision Loss in Inherited Retinal Dystrophies: A Multimodal Longitudinal Study Protocol

Verroca, A.; Franchin, E.; Mele, S.; Siviero, I.; Busch, I. M.; Benamati, A.; Sanchez-Lopez, J.; Quisisana, C.; Filosa, A.; Marino, V.; Colombo, L.; Cesari, P.; Rimondini, M.; Dell'Orco, D.; Cecchini, M. P.; Mazzi, C.; Savazzi, S.

2026-08-19 ophthalmology 10.64898/2026.08.18.26360630 medRxiv
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Individuals with inherited retinal dystrophies (IRDs) undergo a slow, genetically heterogeneous loss of vision, yet how the visual cortex and non-visual sensory, motor, and psychological systems adapt to this deprivation remains poorly characterized. Existing evidence comes mainly from single-modality, cross-sectional studies that rarely account for genetic heterogeneity, making it hard to distinguish adaptive change from a direct, non-retinal mutation effect, since several IRD genes are not retina-specific. To address this gap, we designed an observational, longitudinal, multimodal protocol that combines ophthalmological, genetic, and in silico characterization with electrophysiological (steady-state visual evoked potentials and TMS-EEG), chemosensory, sensorimotor, and psycho-personological assessments. Patients aged 18 to 75 years with rod-cone (retinitis pigmentosa, Usher syndrome) or cone and cone-rod dystrophies will be assessed at baseline (T0) and at an 18-month follow-up (T1); sighted controls, matched for age, sex, and handedness, will complete the same battery once. Importantly, pairing genotypic with phenotypic data allows changes in non-visual domains to be interpreted against, rather than independently of, each patient's molecular background. We expect individuals with IRDs to differ from controls in visual cortical responsiveness and in selected non-visual sensory and sensorimotor measures, with genotype-related differences explored where sample size permits. Given the rarity of IRDs, the design is exploratory and emphasizes effect sizes and individual variability over large-sample inference. The protocol was approved by the Ethics Committee of the University of Verona (CARP 08.R1/2024) and follows the Declaration of Helsinki and the GDPR; findings will be disseminated through peer-reviewed publications and shared with patients and IRD patient associations.

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Droplet Digital PCR as a First-Line Detection Tool in the Genetic Diagnosis of Vascular Anomalies

Lane, T.; Green, T. E.; Garza, D.; Brown, N. J.; de Silva, M. G.; Bennett, M. F.; Tubb, C.; Macdonald, S. M. W.; Gascoigne, A.; Phillips, R. J.; Slavin, J.; D'Arcy, C.; MacGregor, D.; Clifford, A.; Pathmanathan, L.; Robertson, S. J.; Bekhor, P.; Simpson, J.; Gooley, S.; Scheffer, I. E.; Berkovic, S. F.; Penington, A. J.; Hildebrand, M.

2026-08-14 genetic and genomic medicine 10.64898/2026.08.11.26359368 medRxiv
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Targeted precision therapies are increasingly used in the treatment of individuals with vascular anomalies (VAs). This increases the need for rapid, accurate and inexpensive genetic diagnosis. Droplet digital polymerase chain reaction (ddPCR) is an alternative to next-generation sequencing (NGS), permitting rapid, highly sensitive interrogation of recurrent pathogenic mosaic variants. We examined the feasibility of ddPCR as a primary diagnostic tool in a large cohort of individuals with VAs. Lesional tissue was collected for ddPCR of up to 46 recurrent pathogenic variants across 16 genes associated with VAs. Specimens were assessed on a subset of assays for each individual based on clinical phenotype. Most individuals who had negative ddPCR results went on to high-depth gene panel or deep exome NGS, or Sanger sequencing. Here we report the phenotypic and molecular findings for 78 newly recruited and tested individuals in addition to the 60 individuals already reported from our cohort. The overall diagnostic yield for our cohort when combined with individuals previously reported was 104/138 (75%). Of 138 individuals tested, recurrent pathogenic variants were detected in 71 (51%) on ddPCR. Variants were most frequently identified in PIK3CA (n=28), TEK (n=18), GNAQ (n=12), or MAP2K1 (n=7). In a further 33 individuals, pathogenic variants were identified on NGS or Sanger sequencing. Our findings indicate that ddPCR is an efficient method achieving a high diagnostic yield in our cohort when used prior to sequencing.

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Proteome Profiling of Human Tear Fluid Following Acute Exercise

Sun, M.; Yao, H.; Liang, M.; Fei, Q.; Cao, J.; Liang, T.; Cui, Q.

2026-08-18 physiology 10.64898/2026.08.12.744559 medRxiv
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Tear fluid is amenable to non-invasive and repeated collection, making it a practical specimen for evaluating exercise-related physiological responses. However, the immediate proteome-wide alterations in tear fluid following acute exercise have not been characterised. In this study, we performed quantitative proteomic profiling of paired tear samples from healthy female participants before and immediately after a single exercise session using data-independent acquisition liquid chromatography-tandem mass spectrometry (DIA-LC-MS/MS). Among the 3,173 identified proteins, 744 were significantly altered post-exercise, of which 484 were up-regulated and 260 down-regulated. Functional enrichment analysis revealed that up-regulated proteins were predominantly associated with translation and ribosome biogenesis, whereas down-regulated proteins were involved in glycan metabolism, lysosomal processing, and extracellular matrix organisation. Collectively, these findings indicate that acute exercise elicits a rapid and coordinated reconfiguration of the tear proteome. This investigation provides a molecular basis for understanding exercise-mediated modulation of tear composition and ocular surface homeostasis.

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Skin Cancer Classification Using Explainable Artificial Intelligence With an Ensemble Model and Rigorous Leakage Free Validation

BARAN, M. T.; KARAKOYUN, O.

2026-09-05 health systems and quality improvement 10.64898/2026.09.02.26362011 medRxiv
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Background: Reliable melanoma classification requires models that capture both local dermoscopic morphology and broader contextual patterns while maintaining auditable, leakageaware internal validation. Objectives: To develop and internally validate an EfficientNetB0-Swin Transformer Tiny ensemble for classifying histopathologically verified dermoscopic images as benign melanocytic lesions or malignant melanoma. Methods: This retrospective diagnostic model-development and internal validation study screened 552,869 ISIC Archive records; filtering and dermatologist review yielded 1,199 uniquepatient and unique lesion images (578 benign and 621 malignant). Images were the predictors and histopathology was the reference. ImageNet pretrained EfficientNetB0 and Swin-T features were fused. Patient independent five fold validation used weighted sampling, mixup, label smoothing, AdamW, early stopping, and five view test time augmentation. Results: Mean accuracy was 0.89325 {+/-} 0.03179, mean receiver operating characteristic area under the curve (ROC-AUC) was 0.96348 {+/-} 0.01695, and mean support weighted F1-score was 0.89300 {+/-} 0.03220. The fold level 95% confidence intervals were 0.8538-0.9327 for accuracy and 0.9424-0.9845 for ROC-AUC. Pooled counts were 526 true negatives, 52 false positives, 76 false negatives, and 545 true positives, yielding 87.76% sensitivity and 91.00% specificity. Qualitative Grad-CAM review showed peripheral artifact activation in two false positives and lesion centered activation in two correctly classified cases; these observations were not systematically scored. Limitations: The validation folds were also used for early stopping and checkpoint selection. Device stratified analysis, systematic interpretability scoring, calibration, and independent external validation were unavailable. Conclusions: The ensemble showed high internal discrimination and is intended only as a clinician facing adjunct. The error audit workflow enables targeted retrospective review, but external validation is required before clinical use or generalizability claims.

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Impact of the sphingolipid metabolizing enzyme β-galactosylceramidase on mitochondrial sphingolipid profile and energetic metabolism in human melanoma cells

Capoferri, D.; Mignani, L.; Corli, M.; Belleri, M.; Kovilakath, A.; Cowart, L. A.; Mitola, S.; Presta, M.; Grillo, E.

2026-08-21 cancer biology 10.64898/2026.08.18.745397 medRxiv
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Mitochondrial plasticity, characterized by the dynamic balance between glycolysis and oxidative phos-phorylation in response to genetic and microenvironmental changes, is a hallmark of melanoma progression. Sphingolipids play a significant role in various aspects of cancer cell biology, including metabolic reprogramming. Previous observations had shown that the lysosomal sphingolipid-metabolizing enzyme {beta}-galactosylceramidase (GALC) rewires the lipid profile of mouse melanoma cells, exerting pro-oncogenic functions, gene silencing leading to a decreased oncogenic activity in murine and human melanoma cells. Here, we have focused on the mitochondrial sphingolipid composition and energetic metabolism in GALC knockout (KO) A2058 human melanoma cells. Targeted analysis of the mitochondrial sphingolipid profile, transcriptomic data, and mitochondrial structural and functional studies indicate that GALC loss drives a sphingolipid-mediated reprogramming of mitochondrial metabolism in absence of major structural alterations, characterized by bioenergetic insufficiency possibly due to ceramide- and sphingomyelin-driven impairment of respiratory chain function. Overall, these data indicate that GALC KO leads to a sphin-golipid-driven mitochondrial metabolic suppression and may provide novel information for the development of efficacious approaches in mitochondrial targeting melanoma therapies.

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Genome sequencing reveals novel pathogenic deep-intronic PCDH15 variants, amenable to antisense oligonucleotide-based splice correction

Rodenburg, K.; Fenwick, L.; Pennings, R.; Haer-Wigman, L.; Ben-Yosef, T.; van Erp, F.; Reurink, J.; Gilissen, C.; van den Born, L. I.; Cremers, F. P. M.; Cohen, Y.; Yntema, H.; de Vrieze, E.; Kremer, H.; de Bruijn, S. E.; Collin, R. W. J.; Roosing, S.; van Wijk, E.

2026-08-24 genetics 10.64898/2026.08.20.746067 medRxiv
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Despite substantial advances in diagnostic testing, 10-15% of Usher syndrome patients remain without a genetic diagnosis, having significant implications for genetic counseling and potential future therapeutic interventions. In this study, genome sequencing data from probands clinically presenting with Usher syndrome were analyzed. Two novel deep-intronic variants were identified in PCDH15, c.3983+3635A>G and c.3123-1728A>G, in two independent patients. Both deep-intronic variants were classified as likely pathogenic and predicted to alter PCDH15 pre-mRNA splicing. Using a minigene splice assay and iPSC-derived photoreceptor precursor cells from patients, we confirmed that both variants lead to the inclusion of a pseudoexon in the PCDH15 transcript introducing a stop codon and subsequent premature termination of protein translation. We designed and evaluated antisense oligonucleotides (ASOs) with the purpose of redirecting aberrant pre-mRNA splicing caused by both deep-intronic variants. For both variants, designed ASOs were successful in restoring normal splicing patterns, highlighting their potential as a future therapeutic intervention strategy to halt the progression of retinitis pigmentosa caused by these novel variants. Overall, these findings contribute to the understanding of Usher syndrome caused by deep-intronic pathogenic variants in PCDH15 and describe for the first time the use of an ASO-mediated splice correction strategy for individuals diagnosed with these variants.

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Spatial Geometry and Prevalence of Tunneling and Undermining in Pressure Ulcers

Frade, S.; Tunyiswa, Z.; Shin, M.; Dirks, R.

2026-09-01 dermatology 10.64898/2026.08.28.26361615 medRxiv
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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.

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Zebrafish prph2a/b and rom1a/b serve distinct functions during cone and rod outer-segment assembly.

Patel, M.; Famulski, J.

2026-08-07 developmental biology 10.64898/2026.08.06.743304 medRxiv
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Inherited retinal disorders are significant contributors of blindness worldwide. Mutations in Peripherin-2 (PRPH2), a highly conserved vertebrate tetraspanin membrane protein responsible for formation and maintenance of OS morphology, have been shown to cause diverse types of inherited photoreceptor cell (PRC) disorders including but not limited to Leber congenital amaurosis, cone-rod dystrophy, and retinitis pigmentosa. In this study we used a cone-rich diurnal zebrafish model to characterize the loss of PRPH2 function. Of the four PRPH2 zebrafish orthologs only prph2a and prph2b were found to be expressed in PRCs. CRISPR-mediated single mutants of prph2a and prph2b did not yield striking rod or cone phenotypes. Double prph2a/2b mutants exhibited early loss of all cone cells, preceded by cone outer segment disorganization in the form of whorls akin to the phenotypes observed in PRPH2+/- mice. Surprisingly rod photoreceptor cells were not affected and in fact exhibited a striking lengthening of rod OSs with normal disc formation. Overgrowth of rod OSs proceeded up to 1 year, but no degeneration was observed. To determine how rod OS can persist without prhp2a/b we targeted rom1a and rom1b using CRISPR. Injection of rom1a/b crRNA resulted in complete loss of both rod and cone OSs in the prph2a/b double mutants. Surprisingly, inhibition of rom1a/b alone resulted in the loss of rod but not cone OSs. These findings suggest that unlike in mammals, zebrafish rom1a/b is essential for rod OS formation while prph2a/b is essential for cone OSs.

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Performance verification of human field of view occluders for light measurement and simulation

Mardaljevic, J.; de Vries, S. W.; van Duijnhoven, J.

2026-08-10 physiology 10.64898/2026.08.04.742779 medRxiv
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The measurement of light received at the cornea of the eye is a paramount consideration for the understanding of the relation between environmental illumination and the non-image-forming effects of light. The field of view (FOV) at the cornea is less than a full hemisphere, because it is partially occluded by human facial morphology. The International Commission on Illumination (CIE) has defined a standard model of human FOV. A suitably designed physical occluder attached to the sensor (of a light meter) has been proposed as a means of incorporating the effect of human FOV when taking measurements. Similarly, when using simulation to predict light received at the cornea, a geometrical description of the occluder at the eye point(s) can be added to the 3D model of the scene. The first occluder model proposed to represent CIE human FOV was enumerated in terms of: the CIE definition; the radius of the occluder; and, the radius of the light sensor disc. We present a simpler model based only on the CIE definition and the occluder radius. Both models were tested using a virtual goniophotometer. Various sensor response functions describing the spatial sensitivity across the sensor disc, including several we characterized through laboratory measurements, were included in the test. For all functions considered, the performance of the simpler occluder model was equivalent to or better than the model first proposed.

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optix regulates abdominal melanin pigmentation in the tobacco hawkmoth Manduca sexta

Chatterjee, M.; Hatto, G. C.; Duplais, C.; Varnell, J.; Raguso, R. A.; Reed, R. D.

2026-08-25 genetics 10.64898/2026.08.20.746068 medRxiv
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Research on butterflies has uncovered a conserved "toolkit" of genes for color pattern development and evolution. One of these genes is optix, a homeobox transcription factor that regulates ommochrome and melanin pigmentation, as well as structural coloration, in nymphalid butterflies. It remains unclear, however, whether optix plays any roles in color patterning outside of the Nymphalidae. We used CRISPR-Cas9 to disrupt optix in the tobacco hornwormmoth Manduca sexta and observed a dramatic abdominal pigmentation phenotype, where orange pigmentation was replaced by black eumelanin. Chemical assays suggest that the orange pigment is not an ommochrome, indicating that optix modulates an alternative, uncharacterized pigment pathway in M. sexta. RNA-seq and chemical analyses of orange and black abdominal scales lead us to speculate that the orange pigment may be a type of melanin, perhaps N-{beta}-alanyldopamine (NBAD) sclerotin. Our results suggest that optix plays a deeply ancestral role in pigment regulation in Lepidoptera, and demonstrates evolutionary flexibility in how it interfaces with pigment chemistry across moths and butterflies.

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Epigenetics for Public Consumption: Evaluating Science Communication Strategies and Practices on YouTube

Raisa, A.; Santaliz-Moreno, I.; Ayala, A.; Hamilton, J. G.; McQueen, A.; Souroullas, G. P.; Maki, J.; Waters, E. A.

2026-08-17 genetic and genomic medicine 10.64898/2026.08.14.26360379 medRxiv
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Background: Epigenetics, the study of reversible changes in gene expression without altering the underlying DNA sequence, is increasingly applied in medical, commercial, and policy contexts. Yet, little is known about how this emerging science is communicated to the public. The purpose of this study was to examine communication strategies, sources, and modalities in epigenetic-related videos on YouTube- the most accessed platform for informal science education. Methods: We conducted a mixed-methods content analysis of 294 YouTube videos on epigenetics by conducting a keyword-based search on October 17, 2023. Video transcripts and meta-data were coded using a codebook developed both deductively and inductively. Qualitative analysis examined how communication strategies were used within videos and identified emergent themes (RQ1). Quantitative analyses examined the frequency of video and channel characteristics (RQ2), and presentation modalities (RQ3). Results: Findings reveal poor alignment with science communication best practices (RQ1): over 92% of videos failed to acknowledge scientific uncertainty, the comprehensibility level exceeded the recommended 8th-grade level (e.g., average readability grade 10.7), and professional research organizations were notably absent. Narrators were mostly male (56.7%) and white-presenting (73.7%) (RQ2). The majority of the videos used multi-modal strategies (e.g., visual texts mixed with animation and voice-over narration) to communicate epigenetic information (RQ3). Conclusion: Findings highlight the need for professional research organizations to be more proactive in public epigenetic communication efforts. Increasing narrator demographic diversity could broaden audience reach. Evidence-based communication tools are needed for health or science communicators discussing epigenetics on social media.

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A Randomized Non-Inferiority Trial of an eHealth Delivery Alternative for Cancer Genetic Testing for Hereditary Cancer (eREACH2)

Lee, K. T.; Egleston, B.; Fetzer, D.; Domchek, S. M.; Fleisher, L.; Wen, K.-Y.; Wagner, L.; Roberts, S.; Howe, S.; Cacioppo, C.; Christiansen, J.; Karpink, K.; Selmani, E.; Mastaglio, E.; Weinberg, M.; Wood, E. M.; Feng, J.; John, S.; Schweickert, K.; Mcleod, B.; Bradbury, A. R.

2026-09-03 genetic and genomic medicine 10.64898/2026.09.01.26361920 medRxiv
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Background: Many at-risk patients lack access to genetic services due to a genetic counselor (GC) workforce shortage. Little is known about how digital alternatives impact patients with and without cancer who meet criteria for genetic testing. Methods: eREACH2 is a randomized 4-arm non-inferiority trial where pre-test (visit 1) and/or return of results (visit 2) GC counseling was replaced with a patient-centered digital intervention. Arms include: A (GC/GC), B (GC/digital), C (digital/GC) and D (digital/digital). Primary outcomes were non-inferiority in uptake of genetic services and change in genetic knowledge and general anxiety from baseline to post-disclosure of results (T0-T2). Secondary cognitive and affective outcomes were assessed using non-inferiority ANOVAs and equivalency chi-squared tests in intention-to-treat and per-protocol analyses. Findings: 773 participants were recruited nationwide; 46.6% from rural areas. Mean age was 51 years (range 20-87), 13% male, 12% non-white, 29% had less than a college education, and 33% had a personal history of cancer. 584 (76%) patients completed testing (14% had a positive result, 16% had a VUS). In the primary ITT analyses, we met the non-inferiority for uptake of genetic services and anxiety, but results were inconclusive for knowledge. Secondary outcomes were heterogeneous across arms. Arm C demonstrated consistently favorable effects, while Arms B and D showed less favorable outcomes in select domains (e.g. satisfaction and MICRA). Patients who received positive or VUS results via digital disclosure had significantly higher MICRA scores - indicating greater negative response to testing. Interpretation: In this large, randomized trial of patients with and without cancer, the eREACH intervention was effective for pre-test counseling, but inconclusive for digital disclosure of results. Exploratory analyses suggest that digital delivery could be a reasonable alternative for individuals receiving negative results, while those receiving positive or VUS results may derive some short-term psychosocial benefit from GC disclosure.