Case-based learning (CBL) requires students to fully engage in class activities, motivates active thinking, and therefore effectively improves the teaching and learning quality. However, CBL method is not commonly used in laboratory courses in medical schools due to the biosafety and the ethical issues of patient samples. Here, we developed a novel method to prepare synthetic sera and doped urine without the need for a patient donor. These materials are safe for both students and teachers and were used in a 3-week biochemistry laboratory CBL course. Fifty-eight second-year undergraduates from Dalian Medical University (China) received the CBL course, while another 56 students in the control group received traditional teaching. In this mode, each biochemical assay was explained and conducted separately without clinical case scenarios. The learning outcomes were assessed via written examinations for all participants, and questionnaires were additionally distributed to students in the CBL group. The results revealed that the CBL course significantly increased their test scores, improved their learning interest, and fostered their self-learning habits and critical thinking with teamwork. As for different genders, more female students endorsed the benefits of the CBL model for skill development, while more male students gave positive feedback on CBL model in terms of stimulating their motivation to study and stated that they preferred CBL model in the future. Notably, this study adopted a quasi-experimental design with grouping based on intact classes and voluntary student participation, which may lead to self-selection bias when interpreting the results.

The gut microbiome and its metabolomic potential in primary Sjögren syndrome (pSS) remain largely unexplored. Here, we perform whole-metagenome shotgun sequencing of fecal samples from 206 pSS patients and 355 non-pSS controls, integrating compositional and functional profiling with serum and fecal metabolomes. pSS is associated with extensive multi-kingdom alterations, including 49 bacterial (e.g., Streptococcus parasanguinis, Ligilactobacillus salivarius, and Veillonella parvula), 19 fungal (notably Candida albicans), and 1,323 viral species. These signatures form robust inter-kingdom correlations and achieve high diagnostic accuracy in an independent validation cohort. Functional and metabolomic analyses reveal enrichment of toxin-related and aromatic pathways and depletion of protective metabolites in patients. pSS-enriched bacteria harbor abundant immunogenic epitopes, virulence factors, and antimicrobial resistance genes, and induce proinflammatory responses ex vivo. Together, these findings outline a multi-faceted microbial framework for pSS and suggest mechanistic links between gut dysbiosis and immune dysregulation.

[This corrects the article DOI: 10.3389/fphar.2026.1705032.].

Idiopathic inflammatory myopathies (IIMs) are systemic autoimmune disorders with unknown etiology. Despite the established link between gut microbes and immunity, the roles of gut bacteriome, mycobiome, and virome in IIM are unexplored. We performed shotgun metagenomic sequencing on fecal samples from 34 IIM patients and 37 healthy controls to profile gut microbiota. Taxonomic, functional, network, and machine-learning analyses revealed microbial dysbiosis and its potential for discriminating IIM. All three microbial kingdoms were significantly altered in IIM. Several inflammation-associated bacterial taxa (e.g., Rothia mucilaginosa, Streptococcus parasanguinis, Trueperella pyogenes) and opportunistic fungi (e.g., Aspergillus spp.) were enriched in IIM, while SCFA-producing bacteria and fungi were depleted. Virome analysis revealed substantial shifts, with higher abundance of Siphoviridae in IIM. Altered viral functional gene profiles suggesting enhanced phage-mediated genome integration, recombination, and bacterial stress adaptation. Multi-kingdom network analysis showed extensive rewiring in IIM, characterized by increased network connectivity and a shift toward fungi-centered ecological hubs, contrasting with bacteria/virus-dominated networks in controls. In machine-learning models, the virome demonstrated the strongest discriminatory power, and viral signatures dominated the combined multi-kingdom classifier (AUC = 0.997). This first comprehensive multi-kingdom gut microbiota analysis in IIM provides a foundation for developing diagnostic and therapeutic strategies.

IntroductionMycobacteria induce host macrophage M2 polarization to construct a kindly environment for their intracellular growth. In our previous study, we found that M. tuberculosis Rv1987 protein induced macrophage polarization to M2-like phenotype. However, little is known about the changes of host metabolites and the effects of related enzymes in this process.MethodsHere, using our previously constructed infection model by M. smegmatis overexpressing Rv1987 protein, we analyzed the alterations of energy metabolism-related metabolites and the function of M2 isoform of pyruvate kinase (PKM2), the key enzyme of glycolysis, in mycobacteria-induced M2 macrophages.ResultsThe results showed that the expression, enzyme activity and nucleus translocation of PKM2 were all impaired in Rv1987-induced M2 macrophages. Activation of PKM2 by its activator TEPP-46 reversed the M2 polarization and enhanced the inflammation of macrophages, and subsequently reduced the mycobacterial load in mouse lung tissues during infection.ConclusionAll these results suggested that host PKM2 is closely associated with M. tuberculosis Rv1987-induced M2 polarization, which can be considered as an intervention target in anti-tuberculosis therapy.

Gut microbiota plays a pivotal role in Parkinson's disease (PD) pathogenesis. However, the role of enteric viruses remains underexplored. Here, we reanalyzed publicly available metagenomic datasets from two independent cohorts, including 79 PD patients and 79 controls, to characterize gut virome profiles and explore the potential role of enteric viruses in PD pathogenesis and early diagnosis. Our findings indicate increased richness and diversity of the gut virome in PD, with 640 vOTUs differing in abundance between groups. Notably, Siphoviridae and Myoviridae were more abundant in PD patients. A variety of viruses enriched in PD or healthy subjects (HS) preferentially infect bacterial hosts that produce short-chain fatty acids. Furthermore, specific viral functional orthologs, such as thymidylate synthase (K00560) and integrases (K14059), displayed notable differences in prevalence between PD-enriched and HS-enriched vOTUs. Finally, we constructed a random forest model using the top 22 most significant vOTUs, which achieved an AUC of 0.822, demonstrating strong performance in distinguishing PD patients from healthy controls. This is the first study to characterize the gut virome profile in PD, laying a robust foundation for future investigations into the underlying mechanisms and early diagnosis strategies for PD as well as other neurodegenerative disorders.

The N-acetylglucosamine-1-phosphate transferase (WecA)is a potential target for developing anti-tuberculosis drugs, due to its critical role in the synthesis of mycobacterial cell wall. The enzymatic study of WecA and the discovery of WecA inhibitors are therefore justified. However, WecA is a membrane protein with 11 transmembrane domains, making it difficult to be obtained, and even more difficult to perform activity studies. In order to gain sufficient WecA protein for activity investigation, the Escherichia coli (E. coli) Lemo21(DE3) strain was utilised in this study. The expression level of WecA was precisely regulated by T7 lysozyme. Purified WecA was obtained by affinity chromatography and identified by mass spectrometry. The kinetic properties of WecA were determined based on the detection of the product UMP. In addition, tunicamycin proved to be a competitive inhibitor. These results will lay theoretical foundations for the elucidation of WecA catalytic mechanism and the development of WecA inhibitors.

Colorectal cancer (CRC) is the third most common cancer globally and the second leading cause of cancer-related deaths. While intestinal microbiota dysbiosis is linked to CRC, the direct role of intratumoral bacteria in metastasis remains poorly understood. In this study, we isolated pathogenic bacteria from CRC tumor tissues, identified as Hungatella hathewayi (H. hathewayi), through the 16S rRNA gene and whole-genome sequencing. We developed specific primers (P48/P52) and polyclonal antibodies for detecting H. hathewayi in samples. Using quantitative real-time PCR (qPCR), we found significant enrichment of H. hathewayi in fecal samples from CRC patients compared to healthy controls, with mean fold changes of 137-fold and 142-fold for primers P48 and P52, respectively. Analysis of tissue samples revealed that H. hathewayi abundance was higher in CRC tumor tissues compared to normal tissues, with mean fold changes of 2.90 for P48 and 3.97 for P52. Fluorescence in situ hybridization (FISH), immunofluorescence (IF), and immunohistochemistry (IHC) confirmed its spatial distribution within tumor tissues. In vitro assays using CRC cell lines demonstrated that H. hathewayi-derived succinate upregulates HIF-1α and SUCNR1 expression and promotes cell metastasis by inducing epithelial-mesenchymal transition (EMT). Collectively, these findings identify H. hathewayi as a novel pro-metastatic bacterium and a potential non-invasive biomarker for CRC diagnosis, providing direct evidence for the role of intratumoral bacteria in CRC progression.

BackgroundInflammatory bowel disease (IBD) involves epithelial barrier disruption, immune dysregulation, and microbial imbalance. The present study investigated the protective mechanisms of Laetiporus sulphureus polysaccharides (LSP) in dextran sulfate sodium (DSS)-induced colitis, focusing on intestinal barrier restoration, immunomodulation, and gut microbiota remodeling.MethodsLSP was structurally characterized using HPLC, FTIR, and SEM analyses, revealing a heteropolysaccharide primarily composed of glucose (55.16%), galactose (16.55%), and mannose (13.52%). Experimental colitis was induced in BALB/c mice with 3% DSS, followed by oral LSP administration (200 or 400 mg/kg). Disease severity, histopathology, barrier markers, cytokine profiles, macrophage polarization, and gut microbiota composition were evaluated using biochemical assays, immunofluorescence, IHC, and 16S rRNA sequencing.ResultsLSP significantly mitigated DSS-induced colitis by reducing the disease activity index by approximately 60% (∼2.5-fold, p < 0.001) and restoring colon length (∼1.5-fold, p < 0.01). Barrier integrity improved via enhanced mucin-2 expression (∼3.5-fold) and tight junction proteins Occludin, Claudin-1, and ZO-1 (∼5–9-fold). LSP suppressed pro-inflammatory cytokines TNF-α, IL-6, and IL-1β (∼2–3-fold) while upregulating anti-inflammatory mediators IL-10 and TGF-β (∼2.5–3-fold), reflecting a rebalanced mucosal immune milieu. 16S rRNA sequencing demonstrated reversal of DSS-induced dysbiosis, characterized by a reduction in pathogenic Escherichia–Shigella (∼3.8-fold) and Enterobacteriaceae (∼3.5-fold), and enrichment of beneficial taxa including Lactobacillus, Bifidobacterium, and Ruminococcus (∼2–4-fold).ConclusionLSP exerts multi-targeted protection against colitis by reinforcing epithelial barrier function, attenuating inflammation, and reshaping gut microbial ecology. These findings highlight LSP as a promising natural therapeutic candidate for IBD. Further metabolomic and meta transcriptomic analyses are warranted to elucidate the microbial metabolites and molecular pathways mediating these protective effects.

The gut microbiome has been implicated in the development of autoimmune diseases, including gout. However, the role of the gut virome in gout pathogenesis remains underexplored. We employed a reference-dependent virome approach to analyze fecal metagenomic data from 102 gout patients (77 in the discovery cohort and 25 in the validation cohort) and 86 healthy controls (HCs) (63 and 23 in each cohort). A subset of gout patients in the discovery cohort provided longitudinal samples at Weeks 2, 4, and 24. Our analysis revealed significant alterations in the gut virome of gout patients, including reduced viral richness and shifts in viral family composition. Notably, Siphoviridae, Myoviridae, and Podoviridae were depleted, while Quimbyviridae, Retroviridae, and Schitoviridae were enriched in gout patients. We identified 359 viral operational taxonomic units (vOTUs) associated with gout. Enriched vOTUs in gout patients predominantly consisted of Fusobacteriaceae, Bacteroidaceae, and Selenomonadaceae phages, while control-enriched vOTUs included Ruminococcaceae, Oscillospiraceae, and Enterobacteriaceae phages. Longitudinal analysis revealed that a substantial proportion of these virome signatures remained stable over 6 months. Functional profiling highlighted the enrichment of viral auxiliary metabolic genes, suggesting potential metabolic interactions between viruses and host bacteria. Notably, gut virome signatures effectively discriminated gout patients from HCs, with high classification performance in the validation cohort. This study provides the first comprehensive characterization of the gut virome in gout, revealing its potential role in disease pathogenesis and highlighting virome-based signatures as promising biomarkers for gout diagnosis and future therapeutic strategies.

Hypertension, one of the most prevalent cardiovascular diseases, has been linked to the gut microbiota. However, there is a lack of well-defined, cross-population validated gut microbial signatures associated with hypertension, particularly at both the bacterial and fungal levels. To address this gap, we conducted a metagenome-wide analysis of fecal samples from 159 hypertensive patients and 101 healthy controls, using two publicly available data sets from the Beijing and Dalian regions. Our results showed that hypertensive patients exhibit a significant reduction in gut bacterial diversity, accompanied by substantial alterations in bacterial composition. A total of 61 bacterial species were identified with significantly different relative abundance between patients and controls across both regions (combined P < 0.05, q = 0.25). Hypertension-enriched species included Lachnospiraceae (Clostridium symbiosum, Enterocloster bolteae) and Clostridium sp. AT4, while Lachnospiraceae bacterium, Firmicutes bacterium, and Clostridium sp. AM49 4BH were significantly decreased in hypertensive patients. In contrast, no significant differences were observed in gut fungal diversity between hypertensive patients and healthy controls, and only minor differences in fungal composition were noted. Specifically, six fungal species were identified as potentially significant in the combined data set (P < 0.05, q = 0.73), but they only Blastomyces emzantsi c231 meet the same consistency across the two cohorts as the bacterial signatures. Furthermore, we developed classification models using gut bacterial and fungal signatures to distinguish hypertension patients from healthy controls. The bacterium-based models achieved area under the curves (AUCs) greater than 0.70 in cross-cohort classification and validation, while the fungus-based models only achieved AUCs between 0.55 and 0.57. In summary, our study identifies cross-cohort gut bacterial and fungal signatures associated with hypertension, suggesting that the gut bacteriome may serve as a more reliable target for hypertension intervention compared to the gut mycobiome. IMPORTANCE:Hypertension (HTN) represents a global health burden affecting billions of individuals worldwide; however, the relationship between HTN and gut microbial ecosystems remains inadequately characterized. This study presents the first cross-cohort microbiome analysis revealing significant alterations in the gut bacteriome of HTN patients, with limited changes observed in the mycobiome. These findings highlight the critical role of the gut bacteriome in the pathogenesis of HTN and provide new microbial biomarkers for early diagnosis. Furthermore, the identification of bacterial species establishes a foundation for future intervention approaches, enhancing the applicability of microbiome research in cardiovascular health and opening new avenues for related studies in this field.

[Objective] To investigate the effect of the MerTK inhibitor UNC2250 on tumor growth in melanoma mice and to preliminarily elucidate its mechanism of action. [Methods] Sixteen healthy C57BL/6 mice were randomly divided into a control group and low-, medium-, and high-dose UNC2250 treatment groups, with 4 mice per group. After establishing a subcutaneous melanoma tumor model, the control group received daily oral gavage of saline, while the treatment groups were administered UNC2250 at doses of 25, 50 and 75 mg/(kg·d), respectively, once daily for 20 consecutive days. Tumor growth, tumor weight, and body weight changes were monitored. The infiltration of tumor-associated macrophages (TAMs) in the tumor microenvironment was detected by immunofluorescence staining and flow cytometry. Additionally, bone marrow-derived macrophages (BMDMs) were cultured in vitro, and M2 macrophages were induced using IL-4. RT-PCR was used to evaluate the effect of UNC2250 on macrophage phenotype polarization. [Results] UNC2250 significantly inhibited tumor growth in melanoma mice in a dose-dependent manner (F=298.50, all P<0.001). Compared with the control group, tumor weight in the low-, medium-, and high-dose UNC2250 treatment groups was significantly reduced (F=194.20, all P<0.001), and tumor volume decreased with increasing doses. UNC2250 had no significant effect on body weight. Within the tumor microenvironment, UNC2250 intervention markedly reduced the infiltration of TAMs. Further analysis showed an increased proportion of M1-type macrophages among TAMs (F=31.95, P-values for comparisons with control group were 0.120, 0.008, and <0.001 for low, medium, and high doses, respectively), and a decreased proportion of M2-type macrophages (F=45.27; P-values were 0.034, <0.001, and <0.001, respectively). In vitro experiment showed that UNC2250 inhibited the polarization of bone marrow-derived macrophages (BMDMs) toward the immunosuppressive M2 phenotype, as evidenced by significantly downregulated mRNA expression of M2 macrophage markers Arg1 and Mgl1. [Conclusions] The MerTK inhibitor UNC2250 suppresses tumor growth in melanoma mice in a dose-dependent manner with good safety, and its intervention is associated with reduced infiltration of tumor-associated macrophages (TAMs) and a shift in macrophage polarization from the M2 to M1 phenotype in the tumor microenvironment.

Rationale: Chronic kidney disease (CKD) is a progressively debilitating condition leading to kidney dysfunction and severe complications. While dysbiosis of the gut bacteriome has been linked to CKD, the alteration in the gut viral community and its role in CKD remain poorly understood. Methods: Here, we characterize the gut virome in CKD using metagenome-wide analyses of faecal samples from 425 patients and 290 healthy individuals. Results: CKD is associated with a remarkable shift in the gut viral profile that occurs regardless of host properties, disease stage, and underlying diseases. We identify 4,649 differentially abundant viral operational taxonomic units (vOTUs) and reveal that some CKD-enriched viruses are closely related to gut bacterial taxa such as Bacteroides, [Ruminococcus], Erysipelatoclostridium, and Enterocloster spp. In contrast, CKD-depleted viruses include more crAss-like viruses and often target Faecalibacterium, Ruminococcus, and Prevotella species. Functional annotation of the vOTUs reveals numerous viral functional signatures associated with CKD, notably a marked reduction in nicotinamide adenine dinucleotide (NAD+) synthesis capacity within the CKD-associated virome. Furthermore, most CKD viral signatures are reproducible in the gut viromes of diabetic kidney disease and several other common diseases, highlighting the considerable universality of disease-associated viromes. Conclusions: This research provides comprehensive resources and novel insights into the CKD-associated gut virome, offering valuable guidance for future mechanistic and therapeutic investigations.

Metabolic syndrome (MetS) remains a significant global public health concern. However, the relationship between MetS, its individual components and melanoma metastasis remains unexplored. We analysed the clinical data of 258 Chinese melanoma patients who had not undergo systemic therapy. Binary logistic regression, adjusted for sex and age, was employed to evaluate the connection between MetS and its components and melanoma metastasis. Of the 258 melanoma patients, 92 met the MetS criteria upon diagnosis. No direct association between MetS and melanoma metastasis was identified. However, specific components of MetS, namely low HDL-cholesterol levels (OR = 2.85, 95% CI:1.50-5.41, p < 0.05) and dysglycaemia (OR = 4.23, 95% CI:1.80-8.96, p < 0.05), were associated with melanoma metastasis. In subgroup analysis, hypertriglyceridemia correlated with melanoma metastasis in non-elderly patients (< 65 years) (OR = 2.69, 95% CI: 1.14-6.33, p < 0.05). Central obesity and hypertension showed no association. A dose-response analysis further indicated that melanoma metastasis risk escalated with increasing fasting blood glucose and blood triglyceride concentrations, and with decreasing blood HDL concentration. Our results suggest that monitoring and managing individual components of the MetS, particularly HDL-cholesterol levels, fasting glucose and triglyceride levels, may have potential prognostic benefits for melanoma in the Chinese population.

Background: The rapid emergence of antibiotic resistance in Acinetobacter baumannii has led the World Health Organization (WHO) to designate it as a “high priority” pathogen. The emergence of multidrug-resistant (MDR) and pandrug-resistant (PDR) strains poses considerable treatment challenges. As antimicrobial resistance (AMR) escalates toward a post-antibiotic era, innovative therapeutic solutions are urgently needed. Objectives: To clone, over-express, and characterize a novel endolysin, LysTAC1, from Acinetobacter phage TAC1 for its antibacterial efficacy against multidrug-resistant bacteria. Methods: A 24 kDa endolysin featuring a glycoside hydrolase Family 19 chitinase domain was tested against carbapenem-resistant Acinetobacter baumannii clinical isolates and various Escherichia coli strains following outer membrane permeabilization with Ethylenediaminetetraacetic acid (EDTA). Stability assays and molecular docking studies were performed. Results: LysTAC1 demonstrated potent lytic activity against Gram-negative bacteria but showed no activity against Gram-positive bacteria (Staphylococcus aureus ATCC 29213 and Enterococcus gallinarum HCD 28-1). LysTAC1 maintained activity across pH 6–9 and temperatures 4–65 °C, with differential sensitivity to metal ions where K+ showed no inhibitory effect at any concentration (0.1–100 mM), and Fe2+ was non-inhibitory at lower concentrations (0.1–1 mM), while Mg2+ and Ca2+ demonstrated concentration-dependent inhibition across the tested range (0.1–100 mM). Molecular docking revealed LysTAC1 interactions with chitinase substrates 4-nitrophenyl N-acetyl-β-D-glucosaminide and 4-nitrophenyl N, N-Diacetyl-β-D-chitobioside, with binding energies of −5.82 and −6.85 kcal/mol, respectively. Conclusions: LysTAC1 shows significant potential as a targeted therapeutic agent against A. baumannii with robust stability under physiological conditions.

Proteus mirabilis, a major catheter-associated urinary tract infection pathogen, forms antibiotic-resistant crystalline biofilms. Our study demonstrates succinic acid's multimodal inhibition of P.mirabilis via multi-omics analyses. At 15 mM, succinic acid reduced bacterial growth (≥70%) and biofilm formation (≥50%). Metabolomics revealed that succinic acid treatment induces dysregulation in the tryptophan and arginine metabolism, nucleotide biosynthesis, and tricarboxylic acid cycle in P.mirabilis. Transcriptomics revealed downregulated ribosomal genes, oxidative phosphorylation, and efflux pumps, alongside upregulated arginine transport. Proteomics showed suppression of T6SS virulence factors and iron acquisition proteins. We propose that succinic acid reduces K6 acetylation of the histone-like nucleoid structuring protein, enhancing its oligomerization to repress T6SS genes and inhibit biofilm formation. By targeting metabolism, virulence, and stress adaptation, succinic acid circumvents single-target resistance, offering a strategy to combat multidrug-resistant P.mirabilis through biofilm disruption and pathogenicity suppression.

The gut viral community has been increasingly recognized for its role in human physiology and health; however, our understanding of its genetic makeup, functional potential, and disease associations remains incomplete. In this study, we collected 11,286 bulk or viral metagenomes from fecal samples across large-scale Chinese populations to establish a Chinese Gut Virus Catalogue (cnGVC) using a de novo virus identification approach. We then examined the diversity and compositional patterns of the gut virome in relation to common diseases by analyzing 6311 bulk metagenomes representing 28 disease or unhealthy states. The cnGVC contains 93,462 nonredundant viral genomes, with over 70

BACKGROUND:Emerging evidence suggests that the gut microbiome plays a key role in metabolic diseases such as non-alcoholic fatty liver disease, yet the contribution of the gut mycobiome remains largely overlooked. METHODS:We performed a comprehensive analysis of publicly available fecal metagenomic sequencing data and matched serum metabolomic profiles from 90 non-alcoholic fatty liver disease patients and 90 healthy controls. A curated fungal genome database was constructed for taxonomic profiling. We integrated fungal, bacterial, and metabolomic data to assess taxon-specific associations, cross-kingdom interactions, and predictive potential. RESULTS:Although overall fungal diversity showed no significant differences between groups, four fungal species-Pseudopithomyces sp. c174, Mucor sp. c176, Aspergillus sp. c25, and Ascochyta c213-were significantly enriched in non-alcoholic fatty liver disease patients. The gut mycobiome explained 38.2% of the variance in serum metabolomic profiles, with several species displaying strong correlations with non-alcoholic fatty liver disease relevant metabolites. For instance, Pseudopithomyces sp. c174 was positively associated with protective metabolites such as glycoursodeoxycholic acid and alpha-linolenic acid, while Aureobasidium c170 and Basipetospora c193 were linked to phenylacetic acid, a metabolite implicated in hepatic lipid accumulation. Network analysis revealed altered fungal-bacterial co-abundance patterns in non-alcoholic fatty liver disease, with fungal taxa such as Alternaria alternata c42 and Malassezia c303 emerging as key hubs. A random forest classifier integrating 42 bacterial and fungal features achieved an AUC of 0.772 for distinguishing non-alcoholic fatty liver disease from controls, highlighting the predictive value of the mycobiome. CONCLUSIONS:Our findings reveal that gut fungal communities are functionally and ecologically altered in non-alcoholic fatty liver disease and contribute to shaping the host metabolic environment. These results underscore the need to incorporate the gut mycobiome into future microbiome-based strategies for non-alcoholic fatty liver disease diagnosis and treatment.

Cutaneous melanoma is the most lethal of all skin tumors. Recently, cuproptosis, a novel form of cell death linked to oxidative phosphorylation, has emerged as an important factor. However, the precise role of cuproptosis in melanoma remains unclear. Our research explored the potential links between cuproptosis-related genes, prognosis, immune microenvironments, and melanoma treatments. Significantly, cuproptosis regulators showed remarkable differences between melanoma and normal tissues, establishing their relevance to melanoma. The newly developed cuproptosis-related gene signature (CGS) demonstrated a robust ability to predict overall survival (OS) in melanoma. We constructed a novel nomogram that combined clinical features with CGS to improve predictive accuracy. In addition, the study revealed correlations between CGS and immune cell populations, including CD8+T cells, Tfh cells, B cells, and myeloid-derived suppressor cells. Within the CGS, Peptidylprolyl isomerase C (PPIC) emerged as the most strongly associated with poor prognosis and drug resistance in melanoma. PPIC was identified as a promoter of melanoma progression, enhancing cell invasiveness while concurrently suppressing CD8+T cell activation. This comprehensive study not only elucidated the intricate connections between CGS, melanoma prognosis, immune microenvironment, and drug resistance but also provided compelling evidence supporting PPIC as a promising biomarker for predicting OS in melanoma treatment.

Biofilm dispersal contributes to bacterial spread and disease transmission. However, its exact mechanism, especially that in the pathogen Mycobacterium tuberculosis, is unclear. In this study, the cellulase activity of the M. tuberculosis Rv0062 protein was characterized, and its effect on mycobacterial biofilm dispersal was analyzed by observation of the structure and components of Rv0062-treated biofilm in vitro. Meanwhile, the metabolite factors that induced cellulase-related biofilm dispersal were also explored with metabolome analysis and further validations. The results showed that Rv0062 protein had a cellulase activity with a similar optimum pH (6.0) and lower optimum temperature (30 °C) compared to the cellulases from other bacteria. It promoted mycobacterial biofilm dispersal by hydrolyzing cellulose, the main component of extracellular polymeric substrates of mycobacterial biofilm. A metabolome analysis revealed that 107 metabolites were significantly altered at different stages of M. smegmatis biofilm development. Among them, a decrease in gamma-aminobutyric acid (GABA) promoted cellulase-related biofilm dispersal, and this effect was realized with the down-regulation of the bacterial signal molecule c-di-GMP. All these findings suggested that cellulase promotes mycobacterial biofilm dispersal and that this process is closely associated with biofilm metabolite alterations.