Search PubMedSearch

SEARCH · Search PubMed

Results for “β-2 microglobulin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

1,430 records · Page 5Linked to original sources

Enhancement flavor quality in Zhao'an Baxian oolong tea through enhanced turning-over process.

A systematical investigation on the effects of turning-over intensity on the flavor formation of Zhao'an Baxian oolong tea (ZBT) was performed, through a comparative analysis of heavy turning-over (HT) and light turning-over (LT) treatments in this study. The tea samples were subjected to proteomic and metabolomic analyses, combined with quantitative descriptive analysis (QDA) and electronic sensory (E-tongue/E-nose) evaluation. The results demonstrate that HT significantly reduced the content of bitter and astringent compounds, such as catechins and flavonol glycosides, while promoting the accumulation of umami-related amino acids. Concurrently, HT enhanced the biosynthesis of key floral and fruity volatiles, such as β-ocimene, geraniol, benzaldehyde, jasmone by activating stress-responsive metabolic pathways. These coordinated biochemical changes, driven by enzyme-catalyzed reactions in response to prolonged mechanical wounding and environmental stress, collectively improved the overall sensory profile of ZBT. These findings provide a mechanistic foundation for improving ZBT production, with clear implications for quality control and flavor-oriented product development.

Tea

Nephropathies Associated with Sickle Cell Trait and How to Study Them.

Sickle cell trait (SCT), which carries a single point mutation in the hemoglobin-β (HBB) gene, has long been considered a benign condition. However, epidemiological evidence challenges this assumption, revealing that individuals with SCT face an elevated risk of renal dysfunction. However, this field of study remains ill-defined as it has focused on sickle cell disease (SCD), where renal complications are severe. As SCT is more prevalent than SCD, consequences of nephropathies in this group translate into a substantial and largely unaddressed public health burden. Clinical data, primarily observational, implicate age and sex in the development of SCT-associated nephropathies. These manifestations span glomerular hyperfiltration, tubular damage, hematuria, renal papillary necrosis, renal medullary carcinoma, and progression to chronic kidney disease, all complications that cluster disproportionately in older male individuals. Despite this, the mechanistic basis of SCT nephropathy, the thresholds at which renal injury becomes clinically significant, and the optimal strategies for early identification and prevention remain inadequately defined. In vitro studies have primarily focused on SCD blood cell biology, with SCT receiving comparatively little attention. Humanized murine models (i.e., Berkeley and Townes) have recapitulated some SCT-associated renal phenotypes but need to be more fully characterized. This review aims to provide an overview of the biology of sickle cell trait nephropathies, the gaps in our knowledge, and the model systems we can use to fill those gaps.

Journal Article

Redox Rewiring in Nicotine-Driven Gastric Carcinogenesis: Uncovering ROS-Dependent Oncogenic Circuits.

SIGNIFICANCE: Nicotine from tobacco products, secondhand smoke, and emerging delivery systems remains a major but underappreciated driver of gastric carcinogenesis (GC). Although reactive oxygen species (ROS) have long been implicated in tumor biology, current models incompletely explain how chronic nicotine selectively reprograms gastric epithelial signaling. This review advances the concept of redox rewiring, whereby nicotine establishes a persistent oxidative state that orchestrates multiple oncogenic programs via spatially compartmentalized NOX signaling. RECENT ADVANCES: We synthesize evidence for a unified model wherein nicotine activates nAChR/β-AR signaling, Ca2+ influx, PKC, and compartmentalized NOX-derived ROS to generate distinct oncogenic outputs. Beyond the established NOX/ROS/NF-κB/MAPK-driven IL-8 and MMP-9 axes, we integrate emerging evidence into three interconnected modules governing EMT/metastasis (ABL1/STAT3/COX-2/periostin), survival/chemoresistance (ERK/GLI1/Bcl-2), and invasion/immune evasion (miR-21/PDCD4). Collectively, these circuits suggest that ROS function not merely as damaging byproducts but as spatially organized signaling mediators dictating tumor behavior. CRITICAL ISSUES: A major challenge is distinguishing established mechanisms from incompletely validated models. The three proposed axes are testable hypotheses requiring experimental validation. Most data derive from in vitro studies with nonphysiologic nicotine concentrations, and artifacts from nonspecific ROS probes are common. Compensatory pathway activation and multi-target effects of natural products remain underexplored. FUTURE DIRECTIONS: We outline a precision-redox oncology roadmap linking pathway-specific biomarkers, mechanistically matched natural products, and biomarker-enriched trials. Priorities include genetic validation of the three axes, time-resolved ROS imaging, and pulsed natural product regimens. By reframing nicotine-driven GC as adaptive redox network remodeling, this review provides a framework for prevention, stratification, and next-generation therapy. Antioxid. Redox Signal. 00, 000-000.

gastric cancer

Durability and Safety of Imeglimin as an Add-On to DPP-4 Inhibitors in Japanese Type 2 Diabetes: The 104-Week FAMILIAR Trial.

AIMS: To evaluate the long-term efficacy and safety of imeglimin added to dipeptidyl peptidase-4 (DPP-4) inhibitors in Japanese patients with type 2 diabetes, focusing on glycemic durability and safety in elderly patients over 104&#x2009;weeks. MATERIALS AND METHODS: This multicenter, randomized, placebo-controlled trial comprised a 24-week double-blind phase (imeglimin 1000&#x2009;mg or placebo twice daily) followed by an 80-week open-label extension in which all patients received imeglimin. Eligible patients had inadequate glycemic control despite DPP-4 inhibitor monotherapy. The main assessment measured HbA1c changes from baseline to week 104. Secondary assessments included meal tolerance tests (MTT) for evaluating physiological changes in &#x3b2;-cell function and insulin resistance and safety monitoring. RESULTS: Of 117 randomized patients, 81 completed 104&#x2009;weeks. In the early-start group that received imeglimin from week 0, the significant HbA1c reduction observed at week 24 (-0.65%) was maintained through week 104 (-0.55%; p&#x2009;<&#x2009;0.001 vs. baseline). The delayed-start group that switched to imeglimin at week 24 achieved similar glycemic control thereafter. Elderly patients (&#x2265;&#x2009;65&#x2009;years) in the early-start group maintained stable HbA1c reduction (-0.58%) without hypoglycemic events over 2&#x2009;years. MTT analysis in the early-start group showed sustained improvements in glucose AUC and insulin sensitivity without unnecessary insulin secretion over time. CONCLUSIONS: Imeglimin added to DPP-4 inhibitors appeared to improve glycemic control for 104&#x2009;weeks, without clear attenuation. The combination was well-tolerated with a low risk of hypoglycemia even in elderly patients. The long-term effect may be associated with improvements in insulin sensitivity. TRIAL REGISTRATION: jRCTs061210082.

Humans

Phytolacca acinosa Roxb. induces intestinal toxicity through the histamine-MLCK-tight junction axis: Integrated evidence from proteomics, metabolomics, intestinal organoids and epithelial barrier validation.

Phytolacca acinosa Roxb. (PR) is a saponin-rich medicinal plant associated with gastrointestinal toxicity, but the mechanisms underlying PR-induced intestinal barrier injury remain unclear. In this study, raw PR extract was analytically characterized by UPLC-ZenoTOF-MS/MS, confirming triterpenoid saponins as the predominant constituents. C57BL/6&#x202f;J mice were orally exposed to characterized PR extract (1.20 or 12.0&#x202f;g/kg for 5&#x202f;h), and Caco-2 cells and mouse intestinal organoids were used to assess epithelial toxicity and barrier disruption. Histopathology, ELISA, FITC-dextran permeability assays, immunofluorescence, CCK-8, LDH release, western blotting, DIA-based proteomics and untargeted metabolomics were integrated to define toxicological mechanisms. PR induced dose-dependent intestinal inflammation and barrier dysfunction, with the ileum as the most sensitive target. PR increased serum DAO and D-lactate and intestinal TNF-&#x3b1; and IL-1&#x3b2;, disrupted organoid morphology, enhanced epithelial permeability, and reduced ZO-1 expression. Proteomics revealed changes in inflammatory, lipid-metabolic, cytoskeletal and tight-junction pathways, including upregulation of MLCK3 and phospholipase-related proteins and downregulation of ZO-1 and ZO-2. Metabolomics identified histidine metabolism disturbance and histamine accumulation. Integrated multi-omics and pharmacological validation indicated that histamine activated the PLC/IP&#x2083;/Ca&#xb2;&#x207a;/CaM/MLCK cascade, promoting MLC phosphorylation, tight-junction disassembly and epithelial leakiness. MLCK inhibition partially restored ZO-1/ZO-2 expression and attenuated PR-induced epithelial injury. These findings identify the histamine-MLCK-tight junction axis as a key mechanism of PR-induced intestinal toxicity and support hazard identification of saponin-rich PR exposure.

Animals

MARK1 suppresses infectious bursal disease virus replication via phosphorylating VP3.

Infectious bursal disease virus (IBDV) of the Birnaviridae family is a non-envelope, double-stranded RNA virus that encodes a VP3 protein with multiple functions, which controls viral genome replication, IFN-&#x3b2; production, and virus traffic in infected cells. Posttranslational modifications (PTMs), such as ubiquitination, of VP3 have been demonstrated for affecting its function and stability. To clarify the mechanism by which VP3 is regulated in IBDV infected cells, we focused on the phosphorylation of VP3. Mass spectrometry analysis identified that microtubule-affinity regulating kinases 1 (MARK1) was a kinase interacting protein of VP3. Inhibitory function of MARK1 in affecting viral replication was validated. We describe the phosphorylation event at the serine 130 (S130) and serine 163 (S163) residues of VP3 mediated by MARK1 via mass spectrometry analysis. Alanine replacement of the phosphorylation sites in VP3 significantly enhanced its RNA-binding activity. Additionally, the mutation of two serine residues led to remarkably improved in its polymerase-enhancing function. We then incorporated the two mutations to rescue recombinant IBDV. Viral growth curve analysis revealed that replication of mutant IBDV was significantly enhanced relative to wild type (WT) virus. In conclusion, we found that VP3 functions are specifically regulated by MARK1 mediated phosphorylation at S130 and S163 and that this regulation suppresses IBDV replication ultimately.

Infectious bursal disease virus

Revealing potential biomarkers and metabolic mechanisms of ovarian aging in hens during late laying period based on machine learning and metabolomics.

Ovarian function decline during the late laying period represents a major bottleneck for the economic efficiency of the global poultry industry. However, the underlying metabolic mechanisms and reliable early-warning biomarkers for ovarian aging remain poorly understood. In this study, we performed the first untargeted LC-MS/MS metabolomics analysis of ovarian tissues from Taihe silky fowls at peak laying (30&#xa0;weeks) and late laying (50&#xa0;weeks) stages, and employed an ensemble machine learning strategy integrating LASSO, random forest, and support vector machine (SVM) algorithms to identify high-confidence core biomarkers of ovarian aging. Gene expression analysis was further conducted to validate the potential molecular mechanisms. Our results showed that the metabolic profiles of ovarian tissues differed significantly between the two groups. A total of 6 core biomarkers were identified, 4 of which were long-chain acylcarnitines. Mechanistic analysis revealed that downregulation of key genes in the carnitine shuttle system led to impaired mitochondrial fatty acid &#x3b2;-oxidation, which in turn triggered excessive oxidative stress and compromised ovarian endocrine function. In conclusion, this study identifies long-chain acylcarnitines as potential metabolic biomarkers for ovarian aging in Taihe silky fowls. These findings provide novel insights into the metabolic basis of poultry ovarian aging and lay a theoretical foundation for the precise regulation of reproductive performance in indigenous poultry breeds.

Animals

Brief Report: Beyond Testing: Exploring the Psychosocial Impact of HIV Self-Testing Among Ugandan Gender-Diverse Sex Workers.

BACKGROUND: The psychosocial effect of HIV self-testing (HIVST) on sex workers' self-esteem, depression, alcohol misuse, perceived sex work stigma, and empowerment remains poorly characterized. We hypothesized that HIVST would reduce sex work stigma and improve these psychosocial outcomes by enabling private, autonomous testing and reducing exposure to stigmatizing healthcare encounters. SETTING: Kampala, Uganda. METHODS: We conducted a secondary analysis of the Empower study (NCT03426670), an open-label randomized trial in which 117 cisgender female, transgender female, and cisgender male sex workers were assigned 1:1 to monthly HIVST plus quarterly clinic-based testing, or to quarterly clinic-based testing alone, and followed for 12 months. Self-esteem (Rosenberg Self-Esteem Scale), depressive symptoms (PHQ-2), alcohol misuse (RAPS4), perceived sex work stigma (adapted Female Sex Worker Stigma Scale), and empowerment were assessed quarterly. Mixed-effects regression models, adjusted for baseline values, evaluated intervention effects. RESULTS: Data from 117 participants were analyzed, including 7 early disenrollments. Over 12 months, HIVST participants reported significantly lower perceived sex work stigma than standard of care participants (&#x3b2; = -0.38, P = 0.04; monthly reduction P = 0.003), although the rate of decline did not differ significantly between arms (interaction P = 0.08). Self-esteem and depressive symptoms improved in both arms, with no between-arm differences (interaction P = 0.41 and 0.32). Alcohol misuse and empowerment showed no significant arm differences. CONCLUSION: HIVST may reduce sex work stigma without adverse psychosocial effects, supporting its integration into combination HIV prevention for gender-diverse sex workers in sub-Saharan Africa.

Humans

Elucidation of the immunotoxicity of PEDOT: PSS on RAW264.7 macrophages by oxidative stress, inflammatory response, and NF-&#x3ba;B pathway activation.

Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) nanoparticles, widely used conductive polymers, pose environmental and health risks due to their nanoscale dispersion. However, the characteristics of PEDOT: PSS in aquatic systems and the underlying mechanisms of its toxicity in animal and cell models remain poorly understood. This study aimed to investigate the toxicological effects of PEDOT: PSS nanoparticles on macrophages, with a focus on RAW 264.7 cells. After an acute exposure to PEDOT: PSS nanoparticles at different concentrations (5, 10, 20 &#x3bc;g/mL), we observed significant impairments in cell viability, proliferation, migration, adhesion, and phagocytosis, as well as morphological alterations. Concurrently, there was a marked upregulation of inflammatory markers, including reactive oxygen species (ROS), tumor necrosis factor-alpha (TNF-&#x3b1;), interleukin-6 (IL-6), and interleukin-1 beta (IL-1&#x3b2;), indicating the induction of oxidative stress and inflammation. Mechanistically, PEDOT: PSS nanoparticles activated the nuclear factor kappa B (NF-&#x3ba;B) signaling pathway, a key regulator of inflammatory responses, suggesting that they may mediate inflammatory responses and cell damage via activation of the NF-&#x3ba;B signaling pathway. These findings reveal the toxic mechanism of PEDOT: PSS nanoparticles in macrophages and provide new insights into their biological safety implications.

Animals

Integrated genomic and biochemical diagnosis of a novel homozygous start-loss variant in AKR1D1 associated with neonatal cholestasis.

INTRODUCTION: Congenital bile acid synthesis defects are rare autosomal recessive disorders that typically present in early infancy with cholestasis, progressive liver dysfunction, and, in severe cases, acute liver failure. These conditions may mimic other metabolic diseases detected in newborn screening, complicating early diagnosis. The AKR1D1 gene encodes &#x394;4-3-oxosteroid 5&#x3b2;-reductase, a key enzyme in primary bile acid synthesis, and pathogenic variants cause bile acid synthesis defect type 2 (OMIM #235555). CASE DESCRIPTION: We report a 3-month-old male infant with severe neonatal cholestasis and a history of elevated tyrosine levels in newborn screening. Pregnancy was high risk and unmonitored, with birth outside a hospital. Parental consanguinity was first-degree. Early metabolic evaluation showed transient normalization of tyrosine levels, but subsequent analyses revealed recurrent hyper-tyrosinemia. Urinary organic acids showed increased 4-hydroxyphenyl metabolites, with absent succinylacetone, excluding tyrosinemia type I. Progressive cholestasis developed, accompanied by coagulopathy, hyperbilirubinemia, hyperammonemia, and markedly elevated alpha-fetoprotein. Imaging revealed no structural liver abnormalities. Clinical exome sequencing identified a novel homozygous start-loss variant in AKR1D1, likely abolishing functional enzyme production. Metabolic studies confirmed increased urinary excretion of 3-oxocholenoic acids consistent with abnormal bile acid synthesis and supporting a diagnosis of bile acid synthesis defect type 2. Oral cholic acid therapy led to stabilization and improvement in clinical and biochemical parameters. DISCUSSION/CONCLUSION: This case illustrates the diagnostic complexity of neonatal cholestasis, particularly when initial metabolic findings suggest alternative etiologies. It highlights the importance of newborn screening as a tool for broader diagnostic suspicion and the critical role of early molecular diagnosis and multidisciplinary care. Timely recognition and targeted therapy can improve outcomes, prevent liver transplantation, and enable accurate genetic counseling, especially in consanguineous families.

Humans

Illicium verum polysaccharide targets fimbriae and flagella to disrupt biofilm and inhibit multidrug-resistant Escherichia coli proliferation.

The widespread dissemination of multidrug-resistant (MDR) E. coli has led to a decrease in the efficacy of antibiotics, posing severe challenges to clinical anti-infective therapy. Owing to their safety, multitarget activities, and low risk of inducing drug resistance, plant polysaccharides represent a promising alternative strategy. In this study, an acidic polysaccharide (IVP-3) was isolated and purified from the medicinal and edible plant Illicium verum, and it was found to inhibit MDR E. coli colonization by disrupting its biofilm. The Mw of IVP-3 was determined to be 35.566&#xa0;kDa. Its backbone consists of &#x2192;4)-&#x3b1;-D-GalpA-6-OMe-(1&#x2192;, &#x2192;4)-&#x3b1;-D-GalpA-(1&#x2192;, &#x2192;4)-&#x3b2;-D-Galp-(1&#x2192;, and &#x2192;3,4)-&#x3b1;-D-GalpA-(1&#xa0;&#x2192;&#xa0;residues, whereas the branched chain is composed of &#x3b1;-L-Araf-(1&#xa0;&#x2192;&#xa0;5)-&#x3b1;-L-Araf-(1&#xa0;&#x2192;&#xa0;attached to the O-5 position of &#x2192;2,5)-&#x3b1;-L-Araf-(1&#x2192;, which is further linked to the O-3 position of the backbone. Mechanistically, IVP-3 disrupts the structure of fimbriae and flagella, inhibits bacterial motility, effectively prevents initial biofilm adhesion, and eradicates preformed mature biofilms. Additionally, IVP-3 damages cell membrane integrity, disrupts the proton motive force, and induces energy metabolism disorder, efflux pump inhibition, and oxidative stress, ultimately leading to bacterial lysis. This study provides a theoretical basis for the development of natural antibacterial agents targeting MDR E. coli biofilms and for the high-value utilization of Illicium verum.

Biofilms

Biomimetic mesoporous silica nanosphere ameliorate experimental autoimmune uveitis by delivering sCD83.

Autoimmune uveitis (AU) is an autoimmune disease that may lead to blindness, but there are currently no precise targeted therapies for its prevention and treatment. Dendritic cell (DC) is key cell involved in the pathogenesis of AU, and specific regulation of their state can help improve AU. In this work, mesoporous silica nanospheres were loaded with the immunomodulator soluble CD83 (sCD83) and subsequently camouflaged with dendritic cell (DC) membranes to fabricate the nanocarrier DCM@MSN/sCD83 for treating experimental autoimmune uveitis (EAU). Research results show that DCM@MSN/sCD83 effectively alleviated the symptoms of uveitis in EAU, reduced the proportion of CD4+CD25-T cell/CD4+CD25+T cell and the percentage of DC in the eyes and cervical lymph nodes. It also decreased the expression of STING in M&#xfc;ller cell. Furthermore, the efficacy of DCM@MSN/sCD83 was found to be primarily targeting DC, and promoted the expression of IL-10 and TGF-&#x3b2;1 in DC by activating the phosphorylated HIF/STAT3 pathway, to induce the production of CD4+CD25+ T. This effect is superior to nanomedicine loaded with dexamethasone. Moreover&#xff0c;DCM enabled the nanocarriers to efficiently cross the blood-eye barrier and reach cervical lymph nodes, thereby regulating peripheral immunity. This research indicate that cell membrane-modified nanoparticles targeting homologous cells can effectively improve treatment efficiency and duration, which is potential therapy strategy for uveitis.

Animals

Contribution of the Arg-33-His replacement in the histidine kinase CpxA to carbapenem and cefiderocol resistance in Serratia marcescens.

OBJECTIVE: The Serratia marcescens ROT_R clinical isolate, which was resistant to almost all &#x3b2;-lactams, including cefiderocol (4 mg/L), was recovered from a neonate 2 months after the isolation of the S. marcescens ROT_S strain that was susceptible to extended-spectrum cephalosporins (ESCs). In this study, we attempted to decipher the mechanism of resistance displayed by the ROT_R isolate. METHODS: The genomes of ROT_S and ROT_R were sequenced using the Illumina and the Oxford Nanopore Technologies. Long and short reads were assembled together, giving rise to a circularized hybrid genome. RESULTS: Genomic comparison between ROT_S and ROT_R disclosed only one mutation (G98A) in the cpxA gene of ROT_R, which led to the Arg-33-His substitution in the histidine kinase of the two-component system CpxA/CpxR. The cpxA alleles of ROT_S and ROT_R were amplified and cloned, thus giving rise to the pCpxA_WT and pCpxA_R33H recombinant plasmids, respectively, which were subsequently introduced into the S. marcescens HatR recipient strain, which lacks functional CpxA. The S. marcescens HatR (pCpxA_R33H) recombinant clone, which produced the altered CpxA_R33H variant, differed from the S. marcescens HatR (pCpxA_WT) recombinant clone, which produced the wild-type CpxA, by enhanced MICs of carbapenems and ESCs, including cefiderocol (1 mg/L). CONCLUSIONS: This study demonstrates that CpxA alteration, such as Arg-33-His substitution, can contribute to cefiderocol resistance. Although it increases slightly the MIC of cefiderocol without resulting per se in clinical resistance, it can contribute, in combination with other additional mechanisms, to achieve a high level of resistance to this siderophore cephalosporin.

Cefiderocol

Blood Metabolomic Signatures of 1-Hour Glucose Predict Cardiometabolic Risk.

BACKGROUND: Elevated 1-hour glucose levels during an oral glucose tolerance test strongly predict type 2 diabetes (T2D) and cardiovascular disease. We investigated whether the fasting blood metabolome predicting 1-hour glucose could be a target for improving &#x3b2;-cell function, long-term glycemic trajectories, and reducing the risks of T2D and coronary heart disease. We also investigated whether plasma microRNAs derived from key metabolic organs regulate changes in a metabolomic risk score (MRS) for predicting 1-hour glucose. METHODS: Untargeted blood metabolomics and a frequently sampled 75-g oral glucose tolerance test were performed in participants from the OmniCarb trial (n=162). In an independent weight-loss dietary intervention trial (POUNDS Lost [Preventing Overweight Using Novel Dietary Strategies]), temporal changes in MRS and plasma microRNAs measured by genome-wide sequencing were analyzed. In addition, associations of MRS at baseline and its 10-year changes with long-term risk of incident T2D and coronary heart disease were prospectively investigated in the NHS (Nurses' Health Study). RESULTS: We created a fasting blood MRS for predicting 1-hour glucose (Pearson r=0.8) and found significant associations with half-day (diurnal) postprandial glucose excursions and insulin secretion after 5-week controlled feeding interventions varying in carbohydrate amount and glycemic index. In the POUNDS Lost trial, diet-induced changes in MRSs were related to 2-year trajectories of glucose metabolism; circulating microRNAs regulating cardiometabolic abnormalities were pivotal factors influencing these changes. In the NHS, women in the top 20% of MRS had a multivariate-adjusted relative risk of 3.80 (95% CI, 2.22-6.51) for T2D and 1.48 (95% CI, 1.04-2.12) for coronary heart disease compared with those in the lowest 20%. In addition, 10-year increases in plasma metabolites related to 1-hour glucose were linearly associated with a higher risk of T2D. CONCLUSIONS: Our findings indicate that fasting blood metabolomic signatures predicting elevated 1-hour glucose reflect disease pathophysiology and could be targets for preventing T2D and coronary heart disease.

blood glucose

Inhibitory mechanism of phloretin on the AgrA LytTR domain-agr operon complex formation and its application in beef.

Staphylococcus aureus (S. aureus) represents a major foodborne pathogen whose enterotoxin production poses significant challenges to food safety due to its high environmental resistance and limited efficacy of conventional sterilization. Since the expression of enterotoxins is predominantly governed by the agr quorum sensing system, targeting this regulatory pathway has become a strategic choice for virulence control. This study elucidated the mechanism by which phloretin, a potential quorum sensing inhibitor, interferes with the agr system to attenuate virulence. To achieve this, the recombinant AgrA LytTR domain was expressed and purified, and its interaction with phloretin was characterized using thermal shift assays (TSA), electrophoretic mobility shift assays (EMSA), and molecular dynamics (MD) simulations. The results showed that phloretin specifically binds to the AgrA LytTR domain, enhancing its thermal stability and disrupting AgrA LytTR-agr operon binding by reducing the free energy of interaction between them, without causing significant structural rearrangement. Mechanistic analysis indicated that phloretin sterically hinders key &#x3b2;-sheet turn residues (HIS169, ASN201, ARG233), thereby impairing DNA recognition, downregulating RNAIII transcription, and inhibiting agr signaling. In cooked beef, phloretin significantly inhibited the secretion of enterotoxins and &#x3b1;-hemolysin, while delaying lipid oxidation and protein degradation, and maintaining the meat texture. These findings suggested that phloretin is a multifunctional substance with anti-virulence, antioxidant, and preservative properties, demonstrating its potential as a natural food preservative.

Phloretin

Acute Performance, Mechanical and Thermal Effects of Isometric Conditioning Versus Standardized Volleyball Pre-Training Activation in Highly Trained Male Players.

This study compared acute performance, neuromuscular, and thermal responses to a maximal isometric conditioning activity (ICA) versus a standardized volleyball pre-training activation (VPA) in highly trained male volleyball players, and to explore putative mechanisms underpinning post-activation performance enhancement (PAPE) considering training load. In a randomized crossover, 14 men (27 &#xb1; 3 y) completed two sessions: VPA (mobility/plyometric drills; 9 min), and ICA comprising 3&#xd7;5&#xd7;3-s maximal isometric back-squat contractions (knee angle 120&#xb0;; 3-min inter-set rest). Countermovement jump (CMJ) height (primary), relative peak power (PP), RSImod, and contraction time (CT) were recorded pre and 3, 6, 9, and 12 min post. Rectus femoris muscle viscoelastic properties and skin surface temperature (SST) were assessed at matched time points. Analyses used repeated-measures ANOVA, responder analysis, correlations, and regression. Period&#xd7;Sequence interactions favored ICA for CMJ and PP when delivered in Period 2 (lower training volume): &#x2206;CMJ was higher under ICA versus VPA (p = 0.005, d = 1.20); PP likewise greater (p = 0.026, &#x3b7;p2 = 0.35). ICA yielded more beneficial responders than VPA (9/14 vs 1/14; McNemar exact p = 0.021). In Period 2, reductions in rectus femoris muscle stiffness independently predicted CMJ gains (&#x3b2;_std = -0.495, p = 0.005), whereas SST changes did not (p = 0.974). RSImod and CT showed no differences. A brief, high-effort isometric squat protocol was associated with superior acute improvements in jump performance compared with a standard volleyball warm-up, but this advantage emerged specifically when the preceding training volume was reduced (Period 2), suggesting that residual fatigue from training may reduce the effects of PAPE. Gains align with neuro-mechanical rather than thermal mechanisms, supporting ICA as a practical, equipment-minimal priming strategy for elite volleyball.

Humans

CoLchicine for Treatment of OsteoArthritis of the Knee (CLOAK): Clinical and biochemical outcomes from a three-month double-blind, placebo-controlled study.

OBJECTIVE: Knee osteoarthritis (KOA) causes pain and progressive disability, but pharmacologic treatments are limited. Colchicine inhibits inflammation that might modulate KOA, but efficacy trials have yielded mixed results. We tested whether colchicine, without concurrent NSAIDs, improved KOA pain, function, synovial effusion size, and OA-associated inflammatory serum biomarkers. METHODS: Participants with symptomatic KOA and radiographic Kellgren-Lawrence grades 2/3 were randomized to receive three months of daily colchicine or placebo in a double-blind manner, with no concurrent NSAID use. The primary outcome was between-group change in visual analog score (VAS) for index knee pain. Secondary outcomes included changes in Knee Osteoarthritis Outcome Scores (KOOS), size (depth in millimeters) of sonographically-identified effusions, acetaminophen use, and changes in OA-related serum biomarkers. RESULTS: From baseline to end of study of 120 enrolled participants, no significant differences were observed in improvement of VAS pain, KOOS scores or effusion size. Subsets of participants with more severe VAS pain, worse radiographic disease, or higher hsCRP or serum urate levels at baseline also showed no significant clinical benefit from colchicine compared to placebo. In contrast to the clinical outcomes, colchicine treatment was associated with significant or trending improvement in multiple OA-related serum biomarkers including hsCRP and &#x3b2;-NGF (p < 0.05) and PGE2, IL-1ra, IL-8, and VEGF (p < 0.16). CONCLUSION: This double-blind placebo-controlled trial of colchicine for KOA failed to demonstrate improvement in pain, function, or synovial effusion size in comparison to placebo at three months. Early improvement in OA-associated inflammatory biomarkers suggests a possible longer-term clinical benefit. Clinical Trials Registration No NCT03913442.

Humans

Reversed unidirectional transport in a Janus polyurethane/alginate dressing for directional postbiotic delivery to infected wounds.

Probiotic-derived postbiotics exhibit significant potential for infected wound control; however, their effective and localized delivery at wound sites remains a challenge. This study developed a polyurethane/alginate composite nonwoven via electrospinning to establish a postbiotic delivery platform for Bifidobacterium bifidum BD-1 (PU/Alg/BD-1). The beaded fibrous hydrophobic PU layer and hydrophilic Alg layer form a wettability gradient, enabling reversed unidirectional fluid transport toward the wound interface while inhibiting backflow. In vitro results showed that PU/Alg/BD-1 exhibited significant antibacterial activity against Staphylococcus aureus and Escherichia coli and good cytocompatibility with a hemolysis rate of <5%. Targeted metabolomic analysis revealed multiple organic acids in the BD-1 metabolites, which contributed to its antibacterial activity. In vivo microbial analysis verified that PU/Alg/BD-1 effectively reduced the relative abundance of Staphylococcus at the wound site while increasing the proportions of Corynebacterium and Psychrobacter. This microbial modulation contributed to infection control in a rat full-thickness infected wound model, accompanied by a shift in the macrophage phenotype and the downregulation of inflammatory factors including IL-6, TNF-&#x3b1;, and TGF-&#x3b2; in the PU/Alg/BD-1 group. Compared with the blank control, conventional gauze, PU/Alg, and BD-1 groups, PU/Alg/BD-1 significantly promoted wound contraction and re-epithelialization and enhanced collagen deposition. Hence, this study provides an effective material construction strategy for the application of probiotic-derived postbiotics to promote wound healing, demonstrates the potential of BD-1 to regulate the wound microenvironment and accelerate healing, and thereby offers a novel approach for the treatment of infected wounds.

Journal Article