Protein arginine methyltransferases (PRMTs) catalyze arginine methylation, a key post-translational modification (PTM) regulating chromatin organization, RNA metabolism, and signaling. Recent studies reveal that PRMT-mediated methylation also modulates liquid-liquid phase separation (LLPS), which organizes membraneless condensates controlling transcription, stress response, and genome stability. Dysregulated PRMT activity disrupts condensate dynamics, contributing to cancer and neurodegenerative diseases. In cancer, PRMT1, PRMT5, and PRMT6 promote tumor progression via methylation-dependent condensates that enhance oncogenic transcription and stress resistance. In the nervous system, PRMT1, PRMT4, PRMT5, PRMT6, and PRMT8 regulate LLPS of proteins, linking aberrant methylation to ALS and Huntington’s disease. This review highlights PRMTs as key modulators of phase separation and potential therapeutic targets in both oncology and neurodegeneration.
In the quantitative characterization of experimental systems the observation of a time-independent response can signify the attainment of thermodynamic equilibrium. However, there are also situations where the time-independence of experimental response merely reflects the attainment of a kinetic steady state. Although quantitative expressions derived on the basis of kinetic steady-state attainment retain validity for a system at thermodynamic equilibrium, those based on attainment of thermodynamic equilibrium do not apply to systems merely reflecting the attainment of a kinetic steady state. This survey of experimental procedures encountered during research endeavours over the past six decades has revealed many situations where the source of the time-independent instrumental response was correctly identified, but also a number where the responses were misinterpreted.
The article presents a study on the disruption of the bacterial membrane by celandine (CME) and dandelion (TOE) extracts containing bioactive compounds responsible for their antibacterial activity. The in vitro microbiological tests showed antibacterial effect both on Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) pathogenic bacteria species. However, in the case of celandine herb extract, the effect was stronger, especially for Gram-positive bacteria. For a deeper understanding of the mechanism of antibacterial action, both studied extracts were subjected to biophysical studies on artificial bacterial lipid membranes, modeled with the Langmuir monolayers technique. The monolayer investigations were performed using two approaches: (i) monitoring the penetration of extracts injected into the aqueous subphase beneath a compressed lipid film, and (ii) comparing surface pressure-area isotherms recorded on a subphase with and without addition of extracts. These experiments confirmed the activity of TOE and CME at the membrane level, demonstrating the penetration of extract components into the membranes and their fluidizing effect. AFM analysis of the domain structures of the films transferred onto solid supports (Langmuir-Blodgett) revealed differences in film topography induced by the extracts and are in a good agreement with the results of biological tests and analytical analyses of the tested extracts. These findings confirm that the stronger antibacterial effect of CME, associated with a higher content of bioactive compounds, exerts a more destructive effect on the bacterial lipid membranes compared to TOE.
Advances in artificial intelligence, particularly in deep learning, are transforming the field of protein structure prediction. AlphaFold has emerged as a benchmark tool due to its remarkable ability to model protein folding based solely on amino acid sequences. Nevertheless, despite these impressive achievements, several prediction failures still occur. In this study, we focus on two multidomain proteins, LicT from Bacillus subtilis and P1 from the Rice Yellow Mottle Virus, that have long resisted structural characterization. Both proteins exhibit inter-domain flexibility, dimerization, and dynamic behavior in response to phosphorylation (for LicT) or zinc binding (for P1). Here, we screen the performances of AlphaFold versions against these two proteins endowed with a complex conformational landscape and show the present impossibility to correctly predict all domains simultaneously.
A quick, noninvasive method based on 31P NMR spectroscopy to measure the pH of samples containing phosphate buffer is presented. By taking advantage of all four phosphate species populated at acidic, mildly acidic, mildly alkaline and alkaline pH, the method is applicable over a wide range of pH values, from 1 to 13. This tool is most precise at pH values near the pKa values, namely from 5.8 to 8.0 and 10.6 to 13.0. To facilitate its use, a web application is presented that calculates the pH value directly from phosphate 31P chemical shift (ppm) when sodium or potassium is the cation: ( https://rmni.iqf.csic.es/software/31phnmr/ ). In addition, the potential of this approach to monitor reactions which generate or consume H+ is illustrated by following the hydrolysis of GTP catalyzed by Ras-like protein in brain 1a (Rab1a), an essential protein linked to Parkinson’s disease and tuberculosis. The intrinsic GTPase rate of Rab1a is found to be 3.3 ± 0.8·10− 3 min at 37 °C, which places Rab1a amoung the Rabs with slow GTPase rates and the longer lived “active” GTP-bound states.
Autosomal recessive nonsyndromic epidermal differentiation disorders (AR-nEDDs), also known as autosomal recessive congenital ichthyosis (ARCI), are rare genetic skin diseases that lack curative treatments and can only be managed symptomatically. Their study is hampered by the limited availability of biological samples and donor tissues. Artificial skin models offer a valuable alternative for experimental research. Here, we generated epidermal skin equivalents (ESE) using primary keratinocytes from patients with AR-nEDDs carrying pathogenic variants in ALOX12B, CYP4F22, and CERS3, as well as immortalized N/TERT-2G cells. Whereas primary cells undergo senescence, N/TERT-2G cells offer a promising alternative to overcome this limitation. Histological staining and qPCR were applied to assess key epidermal proteins and AR-nEDD-related gene expression in patient- and control-derived models. Patient-derived ESE reproduced the major histopathological features and protein expression patterns characteristic of AR-nEDDs. In contrast, N/TERT-2G-based models showed earlier expression of 12R-LOX, CYP4F22, and CERS3 proteins in epidermal layers compared to healthy donor equivalents. These findings suggest that N/TERT-2G cells represent a reproducible platform for future gene-editing approaches of modelling epidermal differentiation disorders. However, as they do not inherently carry pathogenic variants, they are particularly suitable for gene-editing approaches such as CRISPR/Cas9-mediated disease modelling. Conversely, patient-derived keratinocyte models remain indispensable for validating disease mechanisms and evaluating therapeutic strategies.
The dermal papilla (DP) is essential to hair follicle development and regeneration. Isolation of human DPs still largely depends on manual microdissection and human DP cells (DPCs) lose their intrinsic properties in vitro. Establishing a culture condition that maintains the biological properties of DPCs allows for identification of cell surface markers that enable cell sorting of living human DPCs. A new DPC culture condition was developed using the combination of a WNT activator, CHIR99021, and recombinant FGF9 (CH + F9). Global gene expression profiling and bioinformatic analyses of DPCs grown under this condition were conducted to identify DPC surface markers enabling live DPC isolation. Compared to a conventional culture condition, CH + F9 increased the expression of the representative DPC biomarkers WNT5A, LEF1 and BMP4 by 3.4-, 3.8- and 60.5-fold (p < 0.01) and better maintained their expression levels after long-term serial passaging. Aggregated CH + F9-treated DPCs unevenly upregulated DP biomarkers further, suggesting that highly potent DPCs can be enriched using a marker for such cells. Bioinformatics analysis of CH + F9-treated and control DPCs identified cell marker candidates, including roundabout guidance receptor 2 (ROBO2). Importantly, ROBO2+ DPCs expressing the representative DP biomarkers WNT5A, VCAN, NOG were successfully sorted from mixed cell suspensions of keratinocytes, fibroblasts and DPCs mimicking enzymatically dissociated human skin. These findings suggest that the new culture condition and cell surface marker for human DPCs established in this study provide useful tools for drug discovery and regenerative medicine to address hair loss diseases.
Vagus nerve stimulation (VNS) modulates systemic inflammation through the cholinergic anti-inflammatory pathway, but its effects on cutaneous inflammatory diseases remain unexplored. We investigated whether invasive VNS could reduce clinical inflammation and proinflammatory cytokines in murine models of psoriasis and atopic dermatitis (AD). C57BL/6 mice received imiquimod 5% cream to induce psoriasiform inflammation, while NC/Nga mice received 2,4-dinitrochlorobenzene (DNCB) to induce AD-like inflammation. Acute invasive VNS (5 Hz/5 ms for 5 min) or sham procedures were performed 6 or 24 h before sacrifice. Cutaneous cytokine levels were assessed by immunoblotting and immunofluorescence staining, while systemic inflammation was evaluated by analyzing splenic and plasma cytokines. VNS reduced TNF-α and IL-6 in imiquimod-treated skin at both 6- and 24-h post-stimulation (TNF-α/6 h: 63%, p < 0.01; IL-6/6 h: 63%, p < 0.01; TNF-α/24 h: 69%, p < 0.001; IL-6/24 h: 60%, p < 0.05). In DNCB-treated skin, VNS decreased TNF-α, IL-1β, and IL-6 at 24 h post-stimulation (TNF-α/24 h: 68%, p < 0.001; IL-1β/24 h: 48%, p < 0.05; IL-6/24 h: 66%, p < 0.01). VNS altered cutaneous CD11b-positive macrophage distribution patterns and reduced splenic cytokine levels (TNF-α and IL-1β) in the psoriasis model (TNF-α/6 h: 73%, p < 0.001; 24 h: 46%, p < 0.05) (IL-1β/6 h: 48%, p < 0.01; 24 h: 41%, p < 0.05) while plasma TNF-α decreased in the AD model (24 h: 32%, p < 0.01). This study provides the first evidence that VNS reduces proinflammatory cytokines in inflammatory skin diseases, supporting clinical translation for dermatological applications.
Dysregulated type I interferon (IFN-I) signalling is implicated in the pathogenesis of several systemic autoimmune conditions, collectively termed type I interferonopathies. Emerging evidence suggests that aberrant IFN-I pathway activity may similarly contribute to certain autoimmune dermatoses, namely granuloma annulare (GA), lichen planus (LP), cutaneous sarcoidosis (CS) and morphea. We sought to investigate this association using large, real-world cohorts, with type I interferonopathies serving as proxies for IFN-I-driven inflammation. Four retrospective cohort studies were conducted in parallel using the TriNetX Global Collaborative Network. Patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sjogren's disease (SjD) and dermatomyositis (DM) were 1:1 propensity score-matched to healthy controls (HCs), and relative risks (RRs) for developing GA, CS, LP and morphea were calculated. Sensitivity analyses compared each interferonopathy cohort to patients with gout and ankylosing spondylitis, rheumatologic conditions not mediated by IFN-I pathways. Increased risk of morphea and LP was observed across all four interferonopathy cohorts relative to HCs. Patients with SLE, SSc and SjD had an increased risk of developing CS. GA risk was significantly increased only among patients with SLE and DM. Sensitivity analyses were broadly corroborative. These findings reveal consistent associations between type I interferonopathies and subsequent development of LP, CS and morphea. The results of these analyses are hypothesis-generating and complement existing evidence of an IFN-I mediated pathogenesis for these dermatoses. Prospective studies employing large, representative cohorts paired with transcriptomic and proteomic technologies for mechanistic confirmation are warranted.
Wound edge assessment is a key component of chronic wound evaluation, but it remains highly subjective and affected by inter-observer variability, particularly when performed on two-dimensional clinical photographs. We retrospectively analysed 1 860 wound images acquired during routine clinical practice and independently annotated by four expert clinicians. An automated image-analysis pipeline was used to segment the wound, standardise the peri-wound border region, and estimate the three-dimensional profile of the wound edge. We first tested whether geometry-derived edge profiles alone could reproduce clinical wound edge categories. We then evaluated whether adding global visual descriptors of wound shape, colour appearance, and surface pattern improved agreement with clinicians. Inter-clinician agreement was low, confirming the intrinsic subjectivity of wound edge classification. Geometry-based analysis identified coherent edge-profile patterns but showed poor correspondence with clinical annotations. In contrast, a supervised classifier incorporating both geometric and visual features achieved agreement comparable to, and in some comparisons higher than, the agreement observed among clinicians. Clinical wound edge assessment is not driven by edge geometry alone. Visual cues such as wound shape, colour appearance, and surface pattern appear to influence expert classification and may contribute to variability. Automated image-based analysis may support more reproducible wound edge assessment, provided that it is externally validated in diverse clinical settings.
Skin cutaneous melanoma (SKCM) continues to pose significant therapeutic challenges owing to its aggressive nature and evolving resistance mechanisms. This study investigates the under-characterized role of Hippo pathway effector TEAD4 in SKCM pathogenesis through integrated multiomics analysis of clinical cohorts (TCGA, GEO, immunotherapy cohorts) combined with functional validation in A375 cell models and xenograft systems. Our pan-cancer analysis identified TEAD4 overexpression as a strong prognostic indicator associated with poor survival and a potential association with inferior immunotherapy response. Functional experiments in A375 cells and xenograft models showed that TEAD4 knockdown impaired proliferation, migration and tumour growth while increasing necroptosis-related markers. Mechanistic investigation showed that TEAD4 directly binds the COL1A2 promoter and promotes its transcription. In A375 cells, COL1A2 overexpression attenuated TEAD4 knockdown-induced changes in AKT/mTOR signalling, necroptosis-related markers and malignant phenotypes. These findings support a TEAD4 and COL1A2 regulatory model associated with SKCM progression, AKT/mTOR pathway activity and necroptosis-related phenotypes, and suggest TEAD4 as a prognostic factor and potential biomarker associated with immunotherapy outcome that requires further validation.
Bitter taste type 2 G protein-coupled receptors (TAS2R GPCRs) detect bitter substances on the tongue, but they are also prevalent in tissues throughout the human body that play a role in cancer and other diseases, making them targets for pharmacological research. However, structural information on G protein (GP)-bound TAS2R complexes resolved by cryogenic electron microscopy (cryo-EM) is available for only 4 of the 25 TAS2Rs. Herein, we show that AlphaFold (AF) predictions of GP-bound TAS2R14 and TAS2R46 agree well with cryo-EM structure determinations, thus suggesting that the AF2 predicted structures for all 25 TAS2Rs could be used as starting points for drug development. Although useful starting points, we show that Molecular Dynamics (MD) studies are needed to refine the AF2 structures to get sufficient accuracy for drug design. We find that the MD simulations agree well with the cryo-EM structures at 85 K, but significant changes occur in the MD structures at 310 K that arise from thermal fluctuations frozen-out in the cryo-EM structure, making them far less pronounced at 85 K. We conclude that for TAS2Rs for which cryo-EM structures are not available, AF2 predicted structures followed by MD at 310 K provide a basis for TAS2R drug discovery.
The relapse of psoriasis precludes a complete cure and can result in multisystem comorbidities, making relapse prevention a critical clinical challenge. Clinically, psoriasis tends to worsen or relapse in winter, but the underlying mechanisms remain unclear. In this study, we utilized an imiquimod (IMQ)-induced psoriasis-like mouse model to investigate the role of cold stress in the exacerbation of psoriasis during winter. Our data indicate that cold stress significantly aggravates IMQ-induced psoriatic lesions. While cold stress alone does not directly induce psoriasis, it can promote the development of psoriasis-like lesions in mice exposed to low doses of IMQ. Single-nucleus transcriptome analysis demonstrated that cold stress leads to the remodelling of macrophage phenotypes in psoriatic lesions, with a notable increase in ACSL1+ macrophages. These cells exhibit higher intracellular neutral lipid content and produce more IL-1β, which in turn stimulates γδT cells to secrete more IL-17A. The increase of ACSL1+ macrophages is associated with cold stress-induced lipid synthesis in dermal adipocytes. Notably, the number of ACSL1+ IL-1β + macrophages is significantly increased in the skin of psoriasis patients in winter. Therefore, targeting the formation of ACSL1+ macrophages may be a potential strategy to prevent the worsening of psoriasis in winter.
Psoriasis (PS) is linked to altered polyamine metabolism, which may drive chronic inflammation and abnormal keratinocyte proliferation. We integrated transcriptomics and single-cell RNA sequencing (scRNA-seq) to identify polyamine metabolism-related genes (PMRGs) as biomarkers for PS and elucidate their mechanisms. Through the application of differential expression analysis, three machine learning algorithms, combined with receiver operating characteristic (ROC) analysis and expression quantification, biomarkers related to polyamine metabolism in PS were identified. Furthermore, the expression of these biomarkers was verified through western blotting. These biomarkers were subsequently incorporated into a diagnostic nomogram. Further investigations of these biomarkers included enrichment analysis and immune infiltration analysis. Additionally, scRNA-seq analysis was conducted to annotate the cell types in PS, providing insights into the cellular mechanisms underlying the progression of PS. In PS samples, biomarkers PSME2, PSMB5, PSMC4, PSMB10 and SMOX were significantly upregulated, achieving an area under the ROC curve (AUC) > 0.9 in GSE13355. Western blotting confirmed their upregulation, aligning with bioinformatics results. These biomarkers were closely associated with inflammation, cell proliferation, energy metabolism and signalling pathways. scRNA-seq identified 11 cell types, with mature dendritic cell (mDC) showing notable proportional differences between PS patients and controls, marking them as key cells. mDC exhibited distinct developmental trajectories with branching heterogeneity, featuring a reduction in early stages and an increase in later stages. Biomarker expression levels were higher in the later stages of mDC differentiation. The five PMRGs-PSME2, PSMB5, PSMC4, PSMB10 and SMOX-identified through comprehensive analyses, emerged as significant biomarkers for PS, providing promising diagnostic targets and mechanistic insights for the early detection and targeted treatment of PS.
Ultraviolet B (UVB) irradiation initiates cutaneous vitamin D-related photochemistry from 7-dehydrocholesterol (7-DHC), which is also the immediate precursor of cholesterol via 7-dehydrocholesterol reductase (DHCR7). Thus, DHCR7 occupies a branch-point position linking cholesterol biosynthesis and UVB-associated vitamin D-related metabolism. How keratinocytes regulate this metabolic relationship under UVB remains unclear. We examined whether OPN1SW is associated with DHCR7 protein abundance, conditioned medium 25-hydroxyvitamin D3 [25(OH)D3] (a vitamin D-related readout) and sterol-pool responses in UVB-exposed keratinocytes. A UVB dose that preserved > 80% cell viability, 10 mJ/cm2, increased OPN1SW protein abundance and reduced DHCR7 protein abundance in human epidermal keratinocytes and HaCaT cells. These changes were accompanied by increased conditioned medium 25(OH)D3 and a reduced cellular sterol-pool readout. OPN1SW overexpression increased DHCR7 protein abundance under basal conditions. Under UVB exposure, OPN1SW overexpression attenuated UVB-associated DHCR7 reduction, attenuated the UVB-associated increase in conditioned medium 25(OH)D3 and partially preserved the sterol-pool readout. Conversely, OPN1SW knockdown exacerbated DHCR7 reduction under UVB and was accompanied by higher conditioned medium 25(OH)D3 and a lower sterol-pool readout. DHCR7 knockdown produced concordant shifts in these readouts, supporting a contributory role for DHCR7. Together, these findings support the presence of a UVB-responsive OPN1SW-DHCR7 module that may contribute to keratinocyte adaptation to UVB exposure.
N-acylmelatonins (NAMs), a class of fatty acid amides featuring melatonin as the polar head group, demonstrate significant biomedical potential. In this study, a homologous series of saturated NAMs (n = 9–18) were synthesized and fully characterized via FTIR, NMR and HRMS. The biophysical self-assembly behaviour was assessed by powder X-ray diffraction and fluorescence spectroscopy. The d-spacing determined from PXRD increases linearly with an increment of 0.90 Å per CH₂ group, suggesting that the NAMs adopt a tilted bilayer structure. Fluorescence spectroscopy was employed to measure the critical micellar concentrations (CMCs) of NAMs by monitoring the spectral changes of 8-anilinonaphthalene-1-sulfonate (ANS). Fluorescence emission and lifetime measurements of NAMs show a red-shift ( 10 nm) in emission maxima and a 2.4-fold emission intensity enhancement due to the hydrophobic acyl chain. Antioxidant properties, determined by DPPH radical scavenging assays, increased with concentration, showcasing potent activity. Notably, NAMs exhibited enhanced antimicrobial efficacy against clinically relevant bacterial and fungal strains, with minimum inhibitory concentrations comparable to standard drugs. In vitro anticancer screening revealed significant cytotoxicity against multiple human cancer cell lines, particularly with medium-chain NAMs. These findings highlight the broad-spectrum therapeutic potential of NAMs, driven by variable acyl chain length, self-assembly characteristics and strong biological applications.
Water-filtered infrared-A (wIRA) has been proposed to enhance tissue perfusion and modulate fibrosis, but clinical evidence in morphea (localised scleroderma) is limited. We conducted a prospective, intra-individual pilot split-study in 10 adults (six female; mean age 47.6 ± 19.0 years). One plaque per patient received wIRA using a Hydrosun device (30 min, three times weekly, for 20 weeks; 60 sessions); a clinically comparable contralateral plaque served as untreated control. Blinded assessments at baseline, after 30 and after 60 sessions comprised high-frequency ultrasound (22 MHz; primary endpoint), durometry, Patient Global Impression of Change and a Skin-Change-Perception scale; safety was recorded throughout. Outcome measurements showed substantial inter-individual variability, and irradiated plaques did not significantly improve compared with baseline or with untreated control plaques. However, treatment was well tolerated; two participants reported transient mild burning during early sessions, and no serious adverse events were observed. Larger, adequately powered trials with optimized irradiation parameters and complete follow-up are warranted to clarify the role of wIRA in morphea.
Geobacter bacteria produce multiheme c-type cytochrome nanowires that are involved in long-range extracellular electron transfer. The ability of these protein nanowires to conduct electrical current makes them promising candidates for electronic devices, offering several functional and sustainable advantages over traditional materials. Therefore, this study focused on synthesizing hybrid protein fibers that mimic the natural Geobacter extracellular nanowires. To achieve this, a mutated PpcA triheme protein variant was used as the building block, with thiol-ene coupling employed to bind the protein molecules. This engineered PpcA variant (PpcAK9CK22C) maintained a structure similar to that of the native protein. Thermal denaturation studies revealed a two-state process, with a melting temperature of 62 ± 1 °C and an enthalpy change of 61 ± 2 kcal/mol. The new protein nanowires showed a lower heme group content than the precursor protein and displayed distinct secondary structure features, with a slight reduction in helical content and an increase in β-sheet and unordered structures. Their thermal stability also differed, as it could not be described by the same model applied to the PpcA variant. Despite these differences, the nanowires retained their ability to undergo redox cycling. Morphologically, they consisted of linear single-protein filaments extending over 300 nm in length.
