Purpose: Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, necessitating the identification of novel therapeutic targets. The E3 ubiquitin ligase WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) has been implicated in various cancers, yet its specific role and underlying molecular mechanisms in CRC are poorly understood. This study aimed to investigate the functional role of WWP2 in CRC progression and to elucidate its regulatory mechanisms. Methods: WWP2 expression was evaluated in CRC patient tissues and cell lines using immunohistochemistry, quantitative real-time polymerase chain reaction, and western blotting. The biological functions of WWP2 were assessed using in vitro assays for cell proliferation, migration, and invasion following adenovirus-mediated overexpression. The molecular mechanism was investigated by analyzing the protein expression levels of p53 and its downstream target, p21, via western blot. An in vivo xenograft mouse model was used to confirm the oncogenic role of WWP2. Results: WWP2 expression was significantly upregulated in CRC tissues. Overexpression of WWP2 promoted CRC cell proliferation, migration, and invasion. Mechanistically, increased WWP2 expression led to a marked reduction in the protein levels of the tumor suppressor p53. Consequently, the expression of the p53 downstream target, the cell cycle inhibitor p21, was also suppressed. In the xenograft model, WWP2 overexpression significantly enhanced tumor growth. Conclusion Our findings demonstrate that WWP2 functions as an oncogene in CRC. It promotes cancer progression by destabilizing the tumor suppressor p53 and downregulating p21. This study highlights the WWP2-p53-p21 axis as a potential novel therapeutic target for CRC.

Dementia is a neuropsychiatric disorder that primarily affects the elderly, leading to a widespread decline in cognitive function and significant impairment of occupational, social, and personal functioning. In addition to cognitive deficits, dementia is frequently comorbid with behavioral and psychological symptoms of dementia (BPSD), such as agitation.When present, these secondary symptoms can exacerbate the clinical course of the disease, reduced treatment responsiveness, increased rates of admission to long-term care facilities, extended hospitalization, higher risk of personal injury and a substantial socioeconomic burden. Given these consequences, early management of BPSD—particularly agitation—is critical to mitigating these risks. Although antipsychotics are commonly prescribed to manage agitation, risperidone remains the only agent approved by regulatory authorities for this indication. Recently, however, brexpiprazole, a medication with a pharmacological profile distinct from that of risperidone, received U.S. FDA approval (on May 11, 2023) for the treatment of agitation associated with Alzheimer’s disease. Agitation is among the most prevalent BPSD manifestations, with symptoms ranging from verbal to physical aggression. Given its recent approval and unique pharmacodynamic properties, brexpiprazole may have strong potential as a therapeutic option for this population. This paper aims to review the pharmacological mechanisms, clinical evidence, and future perspectives of brexpiprazole as a novel therapeutic option for managing agitation in patients with Alzheimer’s disease.

Objective:This study aims to investigate the expression of uridine diphosphate-glucose[]pyrophos-phorylase 2(UGP2)in breast cancer(BC)tissues and its oncogenic mechanism,assessing its potential value as a diag-nostic and prognostic biomarker for breast cancer.Methods:(1)Online database analysis was conducted to assess UGP2 mRNA and protein expression levels in breast cancer and explore their correlation with clinical characteristics.Im-munohistochemistry(IHC)was used to verify UGP2 expression in human breast cancer tumor tissues and evaluate its relationship with clinicopathological features.(2)Kaplan-Meier survival analysis and COX regression models were used to analyze the impact of UGP2 expression on breast cancer patient prognosis.(3)Bioinformatics methods were em-ployed to investigate the correlation between UGP2 and tumor immune cell infiltration,and to predict the biological func-tions and associated signaling pathways of UGP2 in breast cancer.Results:(1)The mRNA and protein expression levels of UGP2 were upregulated in breast cancer tissues(both P<0.05),and were negatively correlated with ER-positive and PR-positive status(OR<1,P<0.05),while positively correlated with Ki-67 levels and the triple-negative breast cancer(TNBC)subtype(OR>1,P<0.05).(2)Elevated expression levels of UGP2 were associated with poorer survival rates in breast cancer patients(both P<0.05)and were identified as an independent adverse prognostic factor for breast cancer(HR=1.40,P<0.05).(3)Functional analysis results suggested that UGP2 may promote tumor progression by regulating metabolism,hormone signaling,and the immune microenvironment.Additionally,UGP2 expression was negatively cor-related with NK cell activation status and positively correlated with the inhibitory state.Conclusion:UGP2 expression is elevated in breast cancer tissues and is closely associated with poor patient prognosis.It may promote cancer pro-gression through mechanisms such as metabolic reprogramming and immune suppression.UGP2 shows promise as a potential biomarker and therapeutic target in breast cancer,providing a basis for personalized treatment.

Objective To investigate the neurovascular coupling(NVC)status in the acute phase of patients with minor ischemic stroke(MIS)or transient ischemic attack(TIA)due to intracranial large artery moderate-to-severe stenosis or occlusion using multimodal MRI techniques and to explore its correlation with quality of life(QoL).Methods This prospective,consecutive study enrolled patients with MIS or TIA due to intracranial large artery moderate-to-severe stenosis or occlusion form the Department of Neurology,the First Affiliated Hospital of Xi'an Jiaotong University,between June 2022 and October 2023.Recruit healthy subjects with matched age,sex,and handedness form the community during the same period.Patients were divided into left-sided involvement and right-sided involvement groups based on the affected side of the responsible vessel,while the healthy subjects were set as the healthy control group.Post-hoc power analysis was performed using G*Power 3.1 software.General characteristics(age,gender,body mass index,education level)were collected and compared across all three groups.Clinical data and QoL assessment were collected and compared between the two patient groups.Collected clinical data including type of cerebrovascular events(TIA,MIS),the National Institutes of Health stroke scale(NIHSS)score at admission,the responsible vessel(internal carotid artery,middle cerebral artery)and its side location,the degree of responsibility artery stenosis(moderate-severe stenosis[50%-99%stenosis rate],occlusion[100%stenosis rate]),the intracranial collateral circulation status(American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology[ASITN/SIR]collateral circulation grading),cerebrovascular risk factors(hypertension,diabetes,hyperlipidemia,smoking history),and the laboratory test indicators at admission(glycated hemoglobin,triglycerides,total cholesterol,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,blood uric acid,blood homocysteine).QoL was assessed using the stroke impact scale(SIS),covering eight functional domains and a patient-reported overall recovery item.Multimodal MR data were acquired for all subjects.Whole-brain cerebral blood flow(CBF)images were generated using statistics parameter mapping 12(SPM 12)software,while regional homogeneity(ReHo)images were generated using DPABI software.The voxel-wise ratio of CBF to ReHo(CBF/ReHo)was calculated as the regional NVC parameter.Differences in regional NVC characteristics were compared between patient groups and the healthy control group.Correlations between NVC parameters and SIS scores within patient groups were explored.Results(1)A total of 38 patients with MIS or TIA due to intracranial large artery moderate-to-severe stenosis or occlusion were included(26 males,12 females,aged 36-69 years,with mean age of[52±11]years),with 23 in the left-sided involvement group and 15 in the right-sided involvement group.Nineteen healthy subjects were included(10 males,9 females,aged 37-67 years,with mean age of[53±10]years).Post-hoc power analysis showed statistical power of 0.808 for comparing the left-sided involvement group with the healthy control group and 0.762 for comparing the right-sided involvement group with control group.(2)No statistically significant differences were found on gender,age,education level,or body mass index across the three groups(all P＞0.05).No statistically significant differences were observed on the type of cerebrovascular event,cerebrovascular risk factors,distribution of the responsible vessel,degree of stenosis in the responsible vessel,admission NIHSS score,or laboratory test results between the two patient groups(all P＞0.05).There were no statistically significant differences in the total SIS score and the scores of subscales between the two patient groups(all P＞0.05).(3)Compared with the healthy control group,the left-sided involvement group exhibited reduced CBF/ReHo values in the left superior and middle temporal gyri,supramarginal gyrus,middle and inferior frontal gyri,precentral gyrus,angular gyrus,postcentral gyrus,insula,and posterior cerebellar lobe(FDR-corrected,all P＜0.05).In the right-sided involvement group,reduced CBF/ReHo values were observed in the right supramarginal gyrus,right postcentral gyrus,inferior temporal gyrus,and insula(FDR-corrected,all P＜0.05).(4)Correlation analysis revealed that the SIS total score in the left-sided involvement group negatively correlated with CBF/ReHo values in the right inferior frontal gyrus(T=-5.91)and the right middle temporal gyrus(T=-6.65,FDR-corrected,both P＜0.05).The SIS subscale score for activities of daily living in the left-sided involvement group showed negative correlations with CBF/ReHo values in the right angular gyrus(T=-7.36),right medial superior frontal gyrus(T=-6.97),right orbitofrontal cortex(T=-8.99),and left thalamus(T=-7.51,FDR-corrected,all P＜0.05).No significant correlation was observed between the SIS total score and CBF/ReHo values in patients with right-sided involvement group.The SIS subscale for communication score in the right-sided involvement group correlated with CBF/ReHo in the left lingual gyrus(T=-12.15),left olfactory cortex(T=-7.68),and right anterior cingulate and paracingulate cortex(T=-9.46,FDR-corrected,all P＜0.05).Conclusions Patients with MIS or TIA due to intracranial large artery moderate-to-severe stenosis or occlusion show abnormal NVC in the acute phase,especially those with left hemisphere involvement,who exhibit more extensive impairments.QoL in left-sided involvement patients is strongly linked to NVC in the right orbitofrontal cortex and right middle temporal gyrus.These findings require further validation in larger-scale studies.

Objective To investigate the neurovascular coupling(NVC)status in the acute phase of patients with minor ischemic stroke(MIS)or transient ischemic attack(TIA)due to intracranial large artery moderate-to-severe stenosis or occlusion using multimodal MRI techniques and to explore its correlation with quality of life(QoL).Methods This prospective,consecutive study enrolled patients with MIS or TIA due to intracranial large artery moderate-to-severe stenosis or occlusion form the Department of Neurology,the First Affiliated Hospital of Xi'an Jiaotong University,between June 2022 and October 2023.Recruit healthy subjects with matched age,sex,and handedness form the community during the same period.Patients were divided into left-sided involvement and right-sided involvement groups based on the affected side of the responsible vessel,while the healthy subjects were set as the healthy control group.Post-hoc power analysis was performed using G*Power 3.1 software.General characteristics(age,gender,body mass index,education level)were collected and compared across all three groups.Clinical data and QoL assessment were collected and compared between the two patient groups.Collected clinical data including type of cerebrovascular events(TIA,MIS),the National Institutes of Health stroke scale(NIHSS)score at admission,the responsible vessel(internal carotid artery,middle cerebral artery)and its side location,the degree of responsibility artery stenosis(moderate-severe stenosis[50%-99%stenosis rate],occlusion[100%stenosis rate]),the intracranial collateral circulation status(American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology[ASITN/SIR]collateral circulation grading),cerebrovascular risk factors(hypertension,diabetes,hyperlipidemia,smoking history),and the laboratory test indicators at admission(glycated hemoglobin,triglycerides,total cholesterol,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,blood uric acid,blood homocysteine).QoL was assessed using the stroke impact scale(SIS),covering eight functional domains and a patient-reported overall recovery item.Multimodal MR data were acquired for all subjects.Whole-brain cerebral blood flow(CBF)images were generated using statistics parameter mapping 12(SPM 12)software,while regional homogeneity(ReHo)images were generated using DPABI software.The voxel-wise ratio of CBF to ReHo(CBF/ReHo)was calculated as the regional NVC parameter.Differences in regional NVC characteristics were compared between patient groups and the healthy control group.Correlations between NVC parameters and SIS scores within patient groups were explored.Results(1)A total of 38 patients with MIS or TIA due to intracranial large artery moderate-to-severe stenosis or occlusion were included(26 males,12 females,aged 36-69 years,with mean age of[52±11]years),with 23 in the left-sided involvement group and 15 in the right-sided involvement group.Nineteen healthy subjects were included(10 males,9 females,aged 37-67 years,with mean age of[53±10]years).Post-hoc power analysis showed statistical power of 0.808 for comparing the left-sided involvement group with the healthy control group and 0.762 for comparing the right-sided involvement group with control group.(2)No statistically significant differences were found on gender,age,education level,or body mass index across the three groups(all P＞0.05).No statistically significant differences were observed on the type of cerebrovascular event,cerebrovascular risk factors,distribution of the responsible vessel,degree of stenosis in the responsible vessel,admission NIHSS score,or laboratory test results between the two patient groups(all P＞0.05).There were no statistically significant differences in the total SIS score and the scores of subscales between the two patient groups(all P＞0.05).(3)Compared with the healthy control group,the left-sided involvement group exhibited reduced CBF/ReHo values in the left superior and middle temporal gyri,supramarginal gyrus,middle and inferior frontal gyri,precentral gyrus,angular gyrus,postcentral gyrus,insula,and posterior cerebellar lobe(FDR-corrected,all P＜0.05).In the right-sided involvement group,reduced CBF/ReHo values were observed in the right supramarginal gyrus,right postcentral gyrus,inferior temporal gyrus,and insula(FDR-corrected,all P＜0.05).(4)Correlation analysis revealed that the SIS total score in the left-sided involvement group negatively correlated with CBF/ReHo values in the right inferior frontal gyrus(T=-5.91)and the right middle temporal gyrus(T=-6.65,FDR-corrected,both P＜0.05).The SIS subscale score for activities of daily living in the left-sided involvement group showed negative correlations with CBF/ReHo values in the right angular gyrus(T=-7.36),right medial superior frontal gyrus(T=-6.97),right orbitofrontal cortex(T=-8.99),and left thalamus(T=-7.51,FDR-corrected,all P＜0.05).No significant correlation was observed between the SIS total score and CBF/ReHo values in patients with right-sided involvement group.The SIS subscale for communication score in the right-sided involvement group correlated with CBF/ReHo in the left lingual gyrus(T=-12.15),left olfactory cortex(T=-7.68),and right anterior cingulate and paracingulate cortex(T=-9.46,FDR-corrected,all P＜0.05).Conclusions Patients with MIS or TIA due to intracranial large artery moderate-to-severe stenosis or occlusion show abnormal NVC in the acute phase,especially those with left hemisphere involvement,who exhibit more extensive impairments.QoL in left-sided involvement patients is strongly linked to NVC in the right orbitofrontal cortex and right middle temporal gyrus.These findings require further validation in larger-scale studies.

Objective This study aimed to investigate the correlation of cerebral perfusion and cognitive function status in patients with minor stroke(MS)or transient ischemic attack(TIA)complicated by severe intracranial arterial stenosis or occlusion(hereafter referred to as ICAS-MSTIA).Methods Retrospectively enrol consecutive ICAS-MSTIA patients admitted to the Department of Neurology,the First Affiliated Hospital of Xi'an Jiaotong University,from June 2023 to May 2024.In the meantime,healthy controls were openly recruited.The ICAS-MSTIA patients were divided into two groups based on the side of intracranial large artery stenosis or occlusion:the left intracranial large artery involvement group and the right intracranial large artery involvement group.All patients with intracranial large artery stenosis or occlusion underwent MR scanning within 2 weeks after the first episode of TIA or MS,while there was no specific time requirement for MR examination in the healthy control group.On the day of MR scanning,the Montreal cognitive assessment(MoCA)scale was used to evaluate the participants'global cognitive function and performance in various cognitive domains,including visuospatial/executive function,naming,attention,language,abstraction,delayed recall,and orientation.General information of all participants was collected,including age,sex,educational level,body mass index,and history of smoking and alcohol consumption.Clinical data were collected from both left and right intracranial large artery involvement groups,including cerebrovascular risk factors(such as,diabetes mellitus,hypertension,and hyperlipidemia),National Institutes of Health stroke scale(NIHSS)score at admission,responsible stenotic or occluded arteries(internal carotid artery,middle cerebral artery),degree of stenosis in the responsible vessel(severe stenosis[stenosis rate 70%-99%],occlusion[stenosis rate100%])and non-responsible vessel(no stenosis[0],mild stenosis[stenosis rate＞0-49%]),collateral circulation compensation(American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology[ASTIN/SIR]collateral circulation classification),and responsible events(TIA,MS).General data and MoCA scale scores were compared across the three groups,while clinical data were compared between the left and right intracranial large artery involvement groups.Statistical parametric mapping 12(SPM 12)was used to perform voxel-wise independent samples t-tests on cerebral blood flow(CBF)differences among the left ICAS-MSTIA group,right ICAS-MSTIA group,and healthy control group,with cluster-level family-wise error(FWE)correction applied for adjustment.Multiple linear regression analysis was conducted to evaluate the relationship between global CBF values and total MoCA scores in ICAS-MSTIA patients with left or right intracranial large artery involvement.Results A total of 33 ICAS-MSTIA patients and 33 healthy controls were enrolled in the study.Among the ICAS-MSTIA patients,21 had left intracranial large artery involvement and 12 had right involvement.(1)Among the three groups,statistically significant differences were observed in the proportions of individuals with reported smoking history(P=0.024)and alcohol consumption history(P=0.011).The left intracranial large artery involvement group had a higher NIHSS score(0[0,2]vs.0[0,0],P=0.044)and a higher proportion of patients with internal carotid artery involvement(13/21 cases vs.2/12 cases,P=0.027)compared with the right side group.No statistically significant differences were observed in other general or clinical data across the three groups or between the two non-control groups(all P＞0.05).(2)Statistically significant differences were found across the three groups in the MoCA scale total score and scores of visuospatial/executive function,attention,language,abstraction,delayed recall,and orientation cognitive domains(all P＜0.05),while no significant difference was noted in the naming score(P=0.063).The left intracranial large artery involvement group had lower total MoCA score and lower scores in visuospatial/executive function,attention,language,abstraction,delayed recall,and orientation in comparison to the healthy control group(all P＜0.016 7).The right intracranial large artery involvement group had significantly lower scores in language,abstraction,and orientation domains than the healthy control group(all P＜0.016 7).Additionally,the left side group had a lower attention domain score than the right side group(P＜0.016 7).No other statistically significant differences were found in pairwise comparisons(all P＞0.016 7).(3)Patients in both the left and right intracranial large artery involvement groups exhibited a significant decrease in CBF in extensive regions on the affected side,including the temporal lobe,dorsolateral prefrontal cortex,and occipital lobe.Furthermore,after correction,in the left involvement group CBF was higher in the contralateral lingual gyrus,cuneus,and calcarine sulcus compared with the healthy control group(P＜0.05).While in the right involvement group,no regions had increased CBF compared to the healthy control group.(4)Multiple linear regression showed positive correlation between CBF in ipsilateral precentral gyrus and superior temporal gyrus,and the total MoCA score in patients with left intracranial large artery involvement(FWE-corrected,P＜0.05).In contrast,there was no correlation between CBF and total MoCA score in patients with right intracranial large artery involvement.Conclusions ICAS-MSTIA patients exhibited various degrees of impairment in cerebral perfusion and cognitive function.A significant positive correlation is observed between these two impairments in patients with left intracranial large artery involvement.

Objective To investigate the feasibility of parallel capillary bundle arrays for physiomimetic impedance modeling and establish a parametric quantification framework,thereby providing a customizable impedance characterization methodology for diverse in-vitro mock circulation researches.Methods Based on the parallel flow resistance and Poiseuille equation,a tube resistance element with multiple parallel-aligned capillary glass tubes was designed and fabricated.The resistance values of the capillary-bundle and a ball valve were measured through constant flow experiments analogous to electrical resistance measurement method.Moreover,a simple lumped-parameter mock circulation loop was constructed and the pressure and flow rate for each node of the loop were measured under different input flow waveforms.An 0D-Windkessel model corresponding to the experiment was developed.The impedance and compliance were adjusted to match the simulated and experimental pressure and flow waveforms.The accuracy of the capillary bundle impedance in pulsatile experiments was verified by using the computational resistance values.Results The constant-flow impedance calibration experiments revealed that the capillary bundle impedance remained unaffected by flow rate variations over a wide flow range.When the capillary bundle impedance was integrated into the pulsatile circulatory system and the same impedance value obtained from the constant-flow calibration was applied in the computational model,the resulting pressure and flow waveforms showed good agreement with those measured in the pulsatile experiments.However,when the ball valves with nominally identical impedance values were inserted in the pulsatile system,the calculated impedance exhibited a two-fold difference,and significant discrepancies were observed between the simulated and experimental terminal flow waveforms.Conclusions The capillary bundle impedance maintains a constant value regardless of flow rate variations.Once the calibrated resistance value is determined through constant flow experiments,it can be directly applied to pulsatile systems.This approach can provide quantitative pulsatile flow conditions for testing various medical devices.

Objective To investigate the mechanical effects of various height combinations of canine long-arm hooks and micro-im-plant anchorage on the retraction of maxillary anterior teeth in clear aligner treatment.It focuses on analyzing the stress distribution within the periodontal ligament and the movement tendencies of the anterior teeth,providing scientific evidence for optimizing orthodon-tic treatment strategies.Methods Three-dimensional finite element models were developed using CBCT scan data of patients and soft-ware including Mimics,Geomagic Studio,and Hypermesh.The models incorporated 16 different configurations of canine long-arm hooks(4,6,8,10 mm)and micro-implant anchorage(6,8,10,12 mm).Elastic traction forces of 3/16,3.5 oz were applied to these models.Simulations assessed how these variables influenced periodontal ligament stress distribution and the movement patterns of the maxillary anterior teeth.Results Stress during anterior teeth retraction was predominantly concentrated in the cervical and apex re-gions of the periodontal ligament,where it interfaced with the alveolar bone,indicating significant local concentration.Increasing the height of micro-implant anchorage and traction hooks markedly reduced positional changes in both the crown and apex.Specifically,when hooks exceeded 8 mm and anchorage heights surpassed 10 mm,canine movement became more uniform,preventing extrusion and minimizing the deepening of the overbite.Additionally,combinations of high traction hooks and high micro-implant anchorage promoted more uniform tooth movement,reducing unnecessary tipping and rotation.Conclusion In the retraction of maxillary anterior teeth with clear aligners,using high-position micro-implant anchorage and high-position traction hooks significantly enhances torque control of anterior teeth and effectively prevents deepening of the overbite.

BACKGROUND:The pathogenesis of steroid-induced osteonecrosis of the femoral head is not yet fully understood.A deep comprehension of the pathology and molecular mechanisms of steroid-induced osteonecrosis of the femoral head,as well as the search for diagnostic markers with high specificity and sensitivity,are crucial for the prevention and treatment of this condition.OBJECTIVE:To identify immune diagnostic markers for steroid-induced osteonecrosis of the femoral head and predict potential drug targets through drug enrichment analysis and molecular docking techniques.METHODS:The study utilized gene expression profile data(GSE123568 and GSE74089)from the GEO databases(a public gene expression database built by the U.S.National Center for Biotechnology Information).R software was used for data normalization and differential gene screening,followed by weighted gene co-expression network analysis(WGCNA)to identify disease-related genes.Immune-related genes were obtained from the GeneCards database and intersected with the differential genes and WGCNA gene sets to select immune-related genes for steroid-induced osteonecrosis of the femoral head.Mendelian randomization was used to validate the potential causal relationship between these immune-related genes and steroid-induced osteonecrosis of the femoral head.Gene Set Enrichment Analysis was conducted to analyze the immune-related pathways involved,and protein-protein interaction networks were used to assess functional associations.Finally,drug enrichment analysis and molecular docking were performed to predict potential drugs targeting these immune-related genes.RESULTS AND CONCLUSION:Three key immune-related genes-RNASEL,SECTM1,and HSPA6-were identified.These genes were highly expressed in steroid-induced osteonecrosis of the femoral head and exhibited good diagnostic potential,which were involved in multiple immune-related signaling pathways.Mendelian randomization analysis confirmed their potential causal relationship with steroid-induced osteonecrosis of the femoral head.Drug enrichment analysis and molecular docking identified nine potential drugs,including β-ecdysterone,showing the possibility of intervening in the pathological process of steroid-induced osteonecrosis of the femoral head by regulating the HSPA6 protein.These findings provide new biomarkers and drug targets for the early diagnosis and personalized treatment of steroid-induced osteonecrosis of the femoral head.They also highlight the potential application of bioinformatics in Chinese biomedical research,facilitating the integration and translational use of international data in local disease studies.

Objective To investigate the effects of synovial fluid from patients with rheumatoid arthritis(RA)on the polarization of normal neutrophils and the MEK/ERK signaling pathway,thereby providing experimental evidence to elucidate the pathological mechanisms of RA and offering novel insights into its treatment.Methods Synovial fluid samples were collected from 20 RA patients and 20 osteoarthritis(OA)patients.ELISA was used to measure the levels of interferon-gamma(IFN-γ),tumor necrosis factor-alpha(TNF-α),transforming growth factor-beta(TGF-β)and interleukin-8(IL-8)in the synovial fluid.Neutrophils were isolated from the peripheral blood of healthy donors,and their purity was confirmed by flow cytometry.Neutrophils were then treated with synovial fluid and divided into four groups:Control(untreated),RA(treated with 10％RA synovial fluid),OA(treated with 10％OA synovial fluid),and anti-IFN-β(treated with 20 μg anti-IFN-β antibody as an N2-type control).Western blot was used to assess the changes in the expression of IFN-γ,TNF-α,TGF-β,MEK,p-MEK,ERK and p-ERK.Additionally,the MEK inhibitor PD0325901 was used to block the MEK/ERK pathway,and subsequent changes in IFN-γ and TGF-β expression in neutrophils were evaluated.Results The levels of IFN-γ,TNF-α,TGF-β and IL-8 in the synovial fluid of RA patients were significantly higher than those in OA patients.After intervention with RA synovial fluid,the relative expression of IFN-γ and TNF-α in neutrophils were significantly increased compared to those in the untreated control group and the OA group.While,TGF-β expression in the RA group was lower than that in both the control and anti-IFN-β groups.The relative expression of p-MEK and p-ERK in the RA group were significantly higher than those in the control,OA and Anti-IFN-β groups.Upon addition of the MEK inhibitor,the relative expression of p-MEK and p-ERK were reduced.Furthermore,in both the RA and OA groups,the relative expression levels of IFN-γ decreased,while the expression of TGF-β increased.Conclusion Synovial fluid from RA patients contains higher of IFN-γ,TNF-αand TGF-β,which activate neutrophils through phosphorylation of the MEK/ERK signaling pathway,promoting their polarization toward the pro-inflammatory N1 phenotype.