搜索结果：culture

Tissue-engineered skin substitutes (TESS) represent a key therapeutic option for extensive cutaneous injuries when autologous grafting is limited; however, current constructs lack skin appendages, particularly hair follicles, resulting in incomplete functional and aesthetic restoration. A central barrier to engineering follicular structures within TESS is the rapid loss of hair-inductive features in cultured human dermal papilla (DP) fibroblasts and the difficulty of recreating epithelial-mesenchymal interactions required for early folliculogenesis. Here, we report a bioengineering platform that integrates self-organizing composite spheroids composed of adult human epidermal keratinocytes (KCs) and DP fibroblasts with laser-micropatterned collagen scaffolds to generate spatially defined hair peg-like structures within human TESS. Under optimized three-dimensional culture conditions, mixed KC-DP spheroids reproducibly undergo polarization, budding, and elongation to form hair peg-like structures that exhibit compartmentalized organization and expression of key follicle-associated markers. Transcriptomic analysis reveals activation of follicular-associated transcriptional programs in KCs, while DP fibroblasts retain DP-associated features under these conditions. When implanted into predefined microwells within collagen-based dermal scaffolds, these spheroids continue coordinated morphogenesis alongside epidermal stratification and dermal matrix formation, yielding engineered skin constructs containing spatially integrated hair peg-like structures. Although maturation into fully developed hair follicles remains to be achieved, this study establishes a scalable, clinically relevant platform for integrating early-stage follicular units into TESS. Collectively, these findings provide a foundation for future efforts toward appendage-inclusive skin regeneration using adult human cells. STATEMENT OF SIGNIFICANCE: Engineering human hair follicles in skin substitutes remains challenging because dermal papilla cells rapidly lose hair-inductive function during laboratory expansion, and existing organoid models are difficult to scale or integrate into engineered skin. Here, we present a laser-micropatterned collagen scaffold that spatially incorporates early-stage follicular units formed from human keratinocytes and dermal papilla cells. Through systematic optimization of cell state, spheroid configuration, culture conditions, and scaffold integration, mixed keratinocyte-dermal papilla cell spheroids reproducibly undergo polarization, budding, and elongation in 3D culture and retain hair peg-like organization after incorporation into micropatterned dermal scaffolds. This work advances hair follicle engineering toward clinically relevant skin constructs for studying human hair biology and regenerative skin therapies.

This study investigated the physicochemical, microbiological, and consumer acceptance of kefir with and without paraprobiotics (inactivated kefir starter culture) and evaluated its effects on streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) in Wistar rats. The pH, titratable acidity, and exopolysaccharide (EPS) values of the kefir samples ranged from 3.52 to 4.52, 0.71% to 1.58%, and 1.02 g/kg to 1.63 g/kg, respectively. The exopolysaccharide content of kefir samples produced by adding an inactive kefir starter culture before and after fermentation was higher than that of the control samples. The apparent viscosity values, flow behaviour index values, and consistency coefficient values of the kefir samples varied between 0.09 and 0.16 Pa·s, between 0.21 and 0.34, and between 1.44 and 2.79 Pa·sⁿ, respectively. During the storage period, the highest taste and overall acceptability scores were observed in kefir samples produced by adding inactive starter kefir culture before fermentation. In blood glucose measurements, although an increase was observed in the groups given kefir samples at the beginning, the values approached those of the control group by the end of the experiment. In the oral glucose tolerance test (OGTT) results, a significant reduction in glucose levels was determined in the kefir groups compared to the T1DM group, while no statistically significant difference was observed among the kefir groups. These findings indicate that kefir, particularly when enriched with inactivated kefir starter culture before fermentation, offers improved textural and sensory profiles. However, the anti-hyperglycaemic potential may be primarily attributed to the kefir matrix, regardless of the addition of paraprobiotics before or after.

Coccidioidomycosis is a systemic fungal infection caused by Coccidioides immitis and Coccidioides posadasii. Although well recognized in parts of the southwestern United States, it remains underdiagnosed in Mexico and Central America. While most cases present as self-limited pulmonary infection, approximately 1% of immunocompetent individuals develop disseminated disease, with coccidioidal meningitis (CM) being the most severe manifestation. We describe a 46-year-old immunocompetent male from Oaxaca, Mexico, who presented with progressive headache, neurocognitive decline, and altered mental status. Initial cerebrospinal fluid (CSF) analysis suggested cryptococcal meningitis, yet cryptococcal antigen testing and fungal cultures were negative. Empirical antifungal therapy produced only partial improvement. Given his occupational exposure in Texas and evolving clinical course, coccidioidomycosis was suspected. Serologic testing (enzyme immunoassay, EIA) and a coccidioidin skin test were positive, and prolonged CSF culture ultimately yielded Coccidioides spp., confirming CM. High-dose fluconazole led to progressive neurologic recovery, and the patient remains asymptomatic on maintenance therapy. This case highlights the diagnostic challenges of CM in regions where coccidioidomycosis is not traditionally considered endemic. Non-specific presentations and initial negative studies may delay diagnosis, underscoring the importance of epidemiologic suspicion, repeated testing, and prolonged fungal culture. Early recognition and timely initiation of azole therapy are essential to prevent the high morbidity and mortality associated with this condition.

Ventilator-associated pneumonia (VAP) is a frequent and serious infection among mechanically ventilated children in pediatric intensive care units (PICUs), with oral colonization playing a key role in its pathogenesis. Effective oral hygiene measures are therefore crucial to reduce VAP incidence and improve clinical outcomes. This study aimed to compare the incidence of VAP in PICU patients receiving routine oral care versus toothbrushing with chlorhexidine, and to evaluate the impact on mechanical ventilation duration, PICU stay, and mortality with secondary outcomes including microbiological colonization, inflammatory markers, and inotropic support requirements. A parallel-group superiority randomized controlled trial. A randomized controlled trial was conducted on 118 children aged 18 months to 16 years, including PICU patients requiring invasive mechanical ventilation for ≥ 48 h. On admission, patients were randomly allocated into two groups: the intervention group received oral care with toothbrushing plus 0.12% chlorhexidine mouth rinse, while the control group received routine care with 0.12% chlorhexidine rinse only. Both procedures were performed three times daily. VAP was diagnosed according to CDC criteria. Quantitative and qualitative analyses assessed variables distinguishing VAP cases from controls, and multivariate logistic regression identified independent predictors of disease severity. The results of our study revealed that VAP occurred in 31 patients (52.5%) in the control group and 25 patients (42.3%) in the intervention group, indicating a lower incidence with toothbrushing plus chlorhexidine, although this difference was not statistically significant (p = 0.36). Among all participants, 45.8% died and 54.2% were discharged. Mortality was higher in the control group (53.7%) compared with the intervention group (46.3%), while discharge rates favored the intervention group (53.1% vs. 46.9%); however, these differences did not reach statistical significance (p = 0.46). Positive sputum cultures were more frequent in the control group (55.6%) than in the intervention group (44.4%), whereas negative cultures were more common among intervention patients (54.7% vs. 45.3%), with no significant difference between groups (p = 0.268). Although adding toothbrushing to routine chlorhexidine oral care did not produce a statistically significant reduction in VAP incidence or mortality, a consistent trend toward clinical benefit was observed across multiple outcome measures, including lower rates of positive sputum cultures, reduced inotropic support requirements, and fewer new pulmonary infiltrates. These findings highlight the potential value of enhanced oral hygiene in the PICU and support the need for larger multicenter studies to confirm its effect. ClinicalTrials.gov, NCT07287566. Registered on November 20, 2025. Retrospectively registered at https://clinicaltrials.gov/ct2/show/NCT07287566 . The full study protocol and the statistical analysis plan are included in this document and are available from the corresponding author upon reasonable request.

Morinda citrifolia (Noni) is a traditional medicinal plant widely utilized in tropical regions for its antioxidant and anti-inflammatory properties. While its traditional applications extend to skin and hair health, its specific pharmacological effects on hair follicle biology-particularly when its phytochemical profile and bioavailability are enhanced through fermentation-remain largely unexplored. This study aimed to investigate the pro-regenerative effects and underlying molecular mechanisms of fermented M. citrifolia extract (FME) as a potential therapeutic intervention for hair loss. The pharmacological effects of FME were evaluated using human dermal papilla cells (hDPCs) and ex vivo human hair follicle organ cultures. Assessments included cell viability, cell cycle progression, protein expression analysis, hair shaft elongation, and transcriptomic profiling. FME significantly enhanced hDPC viability and promoted cell cycle progression into the S-phase. Mechanistically, FME activated Wnt/β-catenin signaling by stabilizing β-catenin, thereby increasing the secretion of key hair growth factors (VEGF, bFGF, IGF2) and enhancing antioxidant defense. In ex vivo cultures, FME induced dose-dependent hair shaft elongation, prolonged the anagen phase, and preserved hair bulb architecture. Transcriptomic profiling revealed that FME upregulated stemness-related and hair structure pathways while downregulating matrix remodeling enzymes and pro-inflammatory signaling networks. FME promotes hair growth through the activation of dermal papilla cells and modulation of follicular signaling networks, primarily via the Wnt/β-catenin axis. These findings provide mechanistic evidence supporting FME as a promising and safe therapeutic candidate for alopecia.

Perfluoroalkyl substances (PFAS) are industrial chemicals with several applications, including heat and water resistance. These chemicals are ubiquitous in our environment, and human exposure to them has been linked to liver injury and disruption of lipid metabolism. This study investigated the effects of PFAS (fluorotelomer sulfonic acids 6:2 FTSA and 8:2 FTSA, and perfluorooctane sulfonamide (PFOSA)) on hepatic lipid metabolism using in vitro human cell models. Initially, we assessed the effects of 10 μM PFOSA, 100 μM 6:2 FTSA, and 100 μM 8:2 FTSA in HepG2 monolayer (2D) cultures, focusing on their impact on lipid metabolism. Subsequently, HepG2 spheroids (3D) were exposed to PFOSA (10 μM), the most active compound tested, to elucidate its effects on lipid metabolism further. In the 3D culture, PFOS (10 μM) was used as a reference compound. The results showed that PFOSA was the most disruptive to gene expression and lipid profiles in both 2D and 3D HepG2 cell cultures among the tested PFAS. PFOSA repressed several genes involved in cholesterol and fatty acid synthesis in both HepG2 monolayer and spheroids (3D). Except for triacylglycerides(TAGs) and ceramide (Cer), most lipid species were significantly elevated in PFOSA-exposed HepG2 2D, compared to control. Notably, the effects of PFOSA were less pronounced in HepG2 spheroids. In HepG2 spheroids, the PFOSA toxicity profile resembled that of PFOS, suggesting a similar mechanism of action. Our findings highlight the need for further research on understudied PFAS.

The growing demand for microalgae-derived products, driven by their antioxidant capacity and high value functional compounds, is intensifying the need for more efficient and durable cultivation systems. However, biofouling remains a critical bottleneck, reducing productivity and increasing operational costs in photobioreactors. Although several antifouling solutions have been proposed, most are opaque and therefore incompatible with light-dependent microalgal processes. In this work, the antifouling performance of two novel transparent materials was evaluated using four species of industrially relevant microalgae: Arthrospira platensis, Tetraselmis chuii, Chlorella sorokiniana, and Haematococcus pluvialis. Their performance was benchmarked against conventional substrates (glass and PMMA) and established coatings, including PDMS and the commercial opaque Hempasil X3®. A sequential experimental approach was adopted. First, the influence of culture media and the N / P molar ratio on biomass productivity and cell adhesion was evaluated to identify representative cultivation conditions. Subsequently, transparent antifouling surfaces were assessed under prolonged culture conditions using the selected nutrient conditions. The results demonstrate that the developed transparent surfaces (with a PEG/PDMS-based coating and PMMA-based rigid material) significantly reduce cell adhesion and protein accumulation under biofouling-promoting conditions, reaching values close to commercial antifouling coatings. Cell adhesion was strongly species-dependent, with C. sorokiniana and H. pluvialis exhibiting the highest adhesion. These materials reduced microalgal adhesion by 45-74 % compared to conventional transparent materials such as PMMA and glass while maintaining high optical transparency within the visible range. Therefore, these transparent materials emerge as a promising strategy to enhance the efficiency, stability, and longevity of microalgae cultivation systems.

Obesity is increasingly recognized as a state of chronic low-grade inflammation associated with altered immune cell function, yet the mechanisms driving these changes remain incompletely understood. This study investigated myeloid cell subpopulations and neutrophil behavior in adult participants exhibiting preclinical obesity (body mass index [BMI] 32-51 kg/m2, n = 12) compared to normal-weight controls (BMI 21-24 kg/m2, n = 9), correlating findings with metabolic and inflammatory markers. Peripheral blood samples were analyzed by flow cytometry to quantify myeloid cell populations and TLR4/IL-1R surface expression. Neutrophils were cultured under normoxic (18% O2) or hypoxic (1% O2) conditions, with or without glutaminase inhibition, to assess spontaneous neutrophil death. Participants with preclinical obesity exhibited increased monocyte numbers and eosinophils, whereas total neutrophil numbers were not significantly different between groups, together with a higher percentage of HLA-DR-/low monocytes and activated immature (CD16-CD11b+CD10-) neutrophils. In participants under 60 yr of age, IL‑1R expression on monocytes was significantly increased in the obesity group. Significant metabolic differences were also noted, including higher A1c (5.9 ± 0.1% vs 5.3 ± 0.1%), hs-CRP (9.01 ± 3.33 vs 0.69 ± 0.17 mg/L), and alkaline phosphatase (102.33 ± 9.67 vs 65.75 ± 5.54 U/L) in the preclinical obesity cohort, alongside decreased mean cell hemoglobin. Ex vivo neutrophil culture revealed that hypoxia reduced spontaneous neutrophil death in both groups; however, this effect was significantly reduced by glutaminase inhibition specifically in neutrophils from participants with preclinical obesity, suggesting a heightened reliance on glutamine metabolism for survival under hypoxia. These findings demonstrate dysregulated myelopoiesis and altered neutrophil behavior in preclinical obesity, providing mechanistic insight into the early immune consequences of metabolic dysfunction.

The muscle-brain axis is critical in neuropsychiatric disorders. However, its role in the antidepressant mechanism of Xiaoyaosan (XYS) remains unclear. This study explored whether XYS exerts antidepressant effects by modulating the muscle FNDC5/Irisin-mediated muscle-brain axis to restore hippocampal synaptic plasticity. LPS-induced mouse model was established for in vivo evaluation. In vitro, siRNA knockdown in C2C12-HT22 Transwell co-culture system was used to investigate the involvement of FNDC5/Irisin signaling in muscle-neuron communication. Neuromuscular organoids were established as a three-dimensional platform to model key features of muscle-neuron interactions. Untargeted metabolomics, immunohistochemistry, immunofluorescence, Western blotting, and ELISA were performed. XYS dose-dependently ameliorated LPS-induced depressive-like behaviors, restored muscle fiber integrity, and reversed hippocampal neuronal loss and synaptic deficits. Metabolomics analysis showed that XYS was associated with normalized metabolite profiles associated with β-alanine and taurine metabolism in the hippocampus and PPAR signaling pathway in the muscle. XYS was also associated with activation of the muscle PPARγ/PGC-1α/FNDC5/Irisin signaling pathway, accompanied by increased circulating Irisin levels and upregulation of hippocampal BDNF, PSD95, and synaptophysin. siRNA knockdown of FNDC5 attenuated the effects of XYS on Irisin secretion and synaptic marker restoration in co-cultured neurons. In organoids, XYS protected both myotube and neuronal compartments from LPS-induced injury. XYS exerts antidepressant effects, at least in part, through the activation of the muscle PPARγ/PGC-1α/FNDC5/Irisin axis and the restoration of hippocampal BDNF-mediated synaptic plasticity. The present findings support a potential role for FNDC5/Irisin in peripheral-to-central signaling associated with the antidepressant effects of XYS. These findings further suggest that the muscle-brain axis may represent a promising therapeutic target for depression and warrants further investigation.

Heavy drinking is a core staple in the culture of college football tailgating. In response to the drinking culture of tailgates, scholars recommend that collegiate recovery programs (CRPs) implement innovative "sober tailgate" programming; however, little is known regarding how many colleges have sober tailgate programs, and how such programs are logistically implemented. As such, the purpose of this study was to explore these issues and contribute to the knowledge base on this topic within a socio-ecological perspective. In the fall semester of 2023, the leaders of CRPs at colleges with a football program and an advertised sober tailgate program were invited to complete an online questionnaire about their tailgate. From a total of 667 colleges with a football program, there were only 14 (2%) that had a CRP that advertised sober tailgate programming. From those, 7 (response rate = 50%) CRP leaders completed the study's questionnaire. CRP leaders reported that a variety of on-campus and off-campus groups (e.g., campus administration, treatment facilities, parents of students) help to fund and support sober tailgate programming. Even with common barriers to program implementation, most CRP leaders perceived sober tailgating as successful, well-attended, and led to a few attendees participating in future campus recovery meetings. Health promotion practitioners should consider implementing sober tailgates, and may want to use this study's findings for planning purposes.

Satellite cells (SCs) are essential for skeletal muscle regeneration, but their function declines with aging, often associated with increased pro-apoptotic signaling. This study investigated the impact of in vitro serum starvation-as a model of acute microenvironmental and nutrient stress-on the apoptosis and differentiation potential of human SCs from young and aged donors. SCs were isolated from the Vastus Lateralis of young and aged subjects and cultured in serum-free medium for up to 72 h. We assessed apoptosis through Annexin V/PI staining, TUNEL assays, and caspase activity measurements, while transcriptional profiles were analyzed via RT-PCR. Aged SCs displayed a significantly higher susceptibility to stress-induced apoptosis compared to young controls, marked by the early upregulation of CASP9 and FOXO1. While typical nucleosomal DNA fragmentation was absent, we observed the activation of caspase-3 after 72 h of starvation. In aged cells, activated caspase-3 co-localized with myogenin and extranuclear DNA at sites of nuclear remodeling. Notably, treatment with a pan-caspase inhibitor (z-VAD-fmk) prevented the formation of micronuclei and myotubes, further highlighting a non-apoptotic role for these enzymes. Aged SCs also showed a distinct cell cycle profile characterized by an enlarged G0/G1 phase and altered expression of CDK and CCNB1 genes. Our findings suggest that in human aged SCs, caspase enzymes serve a dual role: mediating a heightened stress response and facilitating the nuclear remodeling necessary for myogenic differentiation. These results clarify how intrinsic aging shapes the response of muscle stem cells under severe environmental and metabolic resource deprivation.

2'-Fucosyllactose (2'-FL), the most abundant human milk oligosaccharide (HMO), has attracted considerable interest for its prebiotic and immunomodulatory functions, with broad applications in infant nutrition. In this study, we report the development of a high-yield, genome-integrated 2'-FL-producing strain based on Escherichia coli MG1655 through systematic modular optimization. Starting from a single-copy BKHT strain (MGC06), we first optimized the copy number of the α-1,2-fucosyltransferase (α-1,2-FT) gene BKHT. Subsequently, the GDP-L-fucose supply was enhanced through coordinated genomic integration of the gene clusters cpsG-cpsB and gmd-fcl, while the multidrug efflux transporter gene mdfA was integrated to improve product export and strain robustness. BKHT copy number was then re-evaluated in the optimized background, with four copies yielding the highest production. The final engineered strain, harboring all genetic modifications stably integrated into the chromosome, produced 17.18 g/L 2'-FL in shake-flask culture. In fed-batch fermentation using a 5-L bioreactor, this strain achieved a titer of 154.12 g/L after 60 h, with a productivity of 2.57 g/L/h. Notably, throughout the entire fermentation process, no antibiotics or inducers were supplemented, underscoring the genetic stability and regulatory compliance of this plasmid-free system. To our knowledge, this represents the highest 2'-FL titer reported to date, positioning our engineered strain as a promising candidate for commercial 2'-FL production.

Natural de novo shoot organogenesis (DNSO) is the spontaneous regeneration of shoots from wound sites outside the shoot apical region through endogenous developmental programs. This regenerative capacity enables plants to recover from severe tissue damage by re-establishing the shoot-root axis. Here, we review current knowledge about the molecular mechanisms of natural DNSO, focusing on transcriptomic and physiological studies in model plants. Accumulating evidence suggests that natural DNSO proceeds through three sequential phases: (i) early wound responses, characterized by the activation of the WIND1-ESR1 module and the establishment of apical-basal auxin asymmetry; (ii) cellular proliferation driven by metabolic and cell-cycle reprogramming; and (iii) cytokinin-mediated establishment of shoot apical meristem identity. We also discuss how these mechanistic insights have been harnessed for practical applications, including tissue culture-free transformation systems such as the cut-dip-budding (CDB) method, and developmental reprogramming strategies that employ ectopic expression of developmental regulator (DR) genes to induce DNSO in otherwise recalcitrant species. Together, these advances illustrate how understanding natural regeneration can guide the development of simplified, broadly applicable plant transformation technologies.

Poly(β-amino ester) or PBAE-based polymer networks are promising degradable biomaterials. This work investigated PBAEs formed from PBAE-diacrylate (PBAE-dA) macromers to assess how network chemistry and structure impact macrophages. PBAE-dAs were synthesized by an Aza-Michael type reaction between a diacrylate (butanediol diacrylate, diethylene glycol diacrylate or poly(ethylene glycol) diacrylate) and benzhydrazide to produce B6, α6, and A6, respectively. B6 PBAE-dA, α6 PBAE-dA, and mixtures thereof have similar molecular weights while α6 and A6 PBAE-dA have the same chemistry, but different molecular weights, allowing investigation into network chemistry and structure, respectively. B6 networks were the least hydrophilic and slowest degrading, while A6 was the most hydrophilic and fastest degrading under accelerated degradation conditions. RAW-Blue™ and primary murine macrophages were pre-activated to mimic the in vivo phenotype and cultured on PBAE networks without and with pre-adsorbed plasma. Macrophage response was assessed by NF-κB activation, inflammatory markers for gene expression (Il1b, Tnfa, Nos2) and cytokine production (IL-6, TNF-α, and IL-18). Comparing across PBAE networks, NF-κB activation was elevated in α6 and A6 but this did not translate to downstream pro-inflammatory cytokine response where there were minimal PBAE-dependent effects. Pre-adsorbed plasma attenuated macrophage activation on B6, α6, and co-polymers thereof but had no effect on A6 PBAE. While the most hydrophilic A6 PBAE induced a greater response across all PBAEs, it was lower compared to the hydrophobic polystyrene control. Collectively, this study further supports PBAEs for in vivo applications because their material properties and degradation rates are readily tunable while minimally affecting macrophage response.

Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus is associated with highly aggressive necrotizing pneumonia characterized by rapid clinical deterioration and high mortality. However, the clinicopathological features of fatal cases, particularly in the forensic setting, remain incompletely defined. We report a fatal case of PVL-positive S. aureus necrotizing pneumonia diagnosed through forensic autopsy and molecular analysis. In addition, a systematic review was conducted according to PRISMA 2020 guidelines. PubMed/MEDLINE and Scopus were searched from database inception to 12 March 2026 to identify published fatal cases of PVL-positive S. aureus pneumonia. A previously healthy 58-year-old man presented with acute respiratory symptoms and rapidly developed severe respiratory failure and septic shock, resulting in death within 24 h of hospital admission. Blood cultures and bronchoalveolar lavage yielded methicillin-susceptible S. aureus. Autopsy revealed bilateral necrotizing hemorrhagic bronchopneumonia, and molecular analysis confirmed PVL positivity. The literature review identified 31 fatal cases. Most cases were characterized by rapid clinical deterioration, frequent septic shock, and hemoptysis or pulmonary hemorrhage. When autopsy was performed, a consistent pattern of necrotizing and hemorrhagic pulmonary infection was observed. PVL-positive S. aureus pneumonia represents a rare but highly aggressive infection that may rapidly progress to respiratory failure and death. The combination of rapid clinical deterioration, hemoptysis, and necrotizing hemorrhagic pneumonia at autopsy represents a distinctive clinicopathological pattern. Integration of autopsy findings with microbiological and molecular investigations is essential for establishing the diagnosis in rapidly fatal infectious deaths.

Pseudochromhidrosis is an underrecognized cause of unusual skin discoloration but is important to include in the differential diagnosis of skin discoloration. This case presents a 17-year-old female with intermittent bright blue discoloration of the right elbow and upper arm following prior orthopedic injuries, prompting extensive evaluation with normal imaging, cardiologic evaluation, and laboratory findings by multiple specialists. Bacterial culture suggested a chromogenic organism consistent with pseudochromhidrosis. Treatment with systemic erythromycin and topical clindamycin resulted in complete and sustained resolution. This case highlights the importance of early recognition of pseudochromhidrosis in preventing unnecessary diagnostic procedures and facilitating timely treatment.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation and joint destruction. Recent studies have indicated that neutrophil extracellular traps (NETs) are closely associated with the senescence of bone marrow mesenchymal stem cells (BMSCs) and the pathogenesis of RA. However, the mechanistic link between NETs and BMSC senescence in RA remains unclear. This study aims to elucidate the molecular mechanism by which NETs induce BMSC senescence and to evaluate the therapeutic effect of low-frequency pulsed electromagnetic fields (PEMFs). In a adjuvant-induced arthritis (AIA) mouse model, NET formation was significantly increased in joint tissues, and BMSCs exhibited a typical senescent phenotype. Using a neutrophil-BMSC co-culture system, we demonstrated that RA-derived neutrophils induced BMSC senescence through NETs, an effect that was reversed by DNase I treatment. Mechanistically, PADI4 derived from NETs interacted with and citrullinated MFN2. This modification reduced MFN2 protein stability via the autophagy-lysosome pathway, subsequently leading to mitochondrial dysfunction and cellular senescence in BMSCs. Furthermore, treatment with low-frequency PEMFs markedly inhibited NET formation, effectively delayed BMSC senescence, and ameliorated joint pathological damage in RA mice. Collectively, these findings reveal that NET-derived PADI4 induces BMSC senescence through citrullination of MFN2, and that PEMFs exert therapeutic effects by inhibiting NET formation and blocking this pathway. This study provides important theoretical insights into the pathogenesis and clinical treatment of RA, and suggests that PEMFs hold promise as a potential therapeutic strategy for RA.