ObjectiveDiscriminating atypical hepatocellular carcinoma (HCC) from other malignancies in liver nodules classified as Liver Imaging Reporting and Data System category M (LR-M) remains a significant diagnostic challenge on conventional ultrasound examination. The LR-M category, originally intended to capture non-HCC malignancies, paradoxically contains up to 63% of atypical HCCs that deviate from classic enhancement patterns, leading to potential misdiagnosis and suboptimal treatment planning. While deep learning has shown promise in HCC diagnosis, most existing models rely exclusively on single-modality ultrasound, overlooking the diagnostic benefits of integrating complementary information from multiple imaging sources. To address this gap, we propose a novel attention-weighted tri-modal ultrasound network (TUS-Net) that integrates contrast-enhanced ultrasound (CEUS), B-mode ultrasound (BUS), and time-intensity curves (TICs) to improve diagnostic accuracy for these clinically challenging lesions. MethodsOur framework incorporates a three-dimensional convolutional neural network (C3D) backbone to extract spatiotemporal features from CEUS videos, capturing dynamic vascular patterns critical for lesion characterization. To effectively fuse complementary modalities, we introduce a dual-channel feature fusion module (DCFFM) that adaptively combines features from CEUS and BUS through channel-wise attention mechanisms, allowing the model to dynamically weigh the contribution of each modality based on diagnostic relevance. Additionally, we propose a temporal intensity feature fusion module (TIFFM) that leverages quantitative hemodynamic information from TICs to guide the model’s attention toward diagnostically critical temporal phases, such as arterial wash-in and portal venous washout. The model is further enhanced by automated lesion localization using YOLOX and class activation mapping for interpretability, ensuring that predictions align with clinically meaningful imaging features. ResultsEvaluated on a tri-modal ultrasound dataset comprising 161 patients with pathologically confirmed LR-M nodules (131 atypical HCC and 30 non-HCC malignancies), our model achieved an accuracy of 86.83%, a sensitivity of 92.50%, a specificity of 75.50%, and an AUC of 89.32% in screening atypical HCC. Compared to single-modality baselines, TUS-Net demonstrated superior specificity, a clinically critical metric given the higher risk associated with misclassifying non-HCC malignancies. Ablation studies confirmed the contribution of each module, with the full model outperforming both standard C3D and 3D ResNet backbones integrated with attention mechanisms. A reader study involving junior and senior radiologists further validated the clinical utility of AI assistance, showing consistent improvements in specificity and inter-reader consistency, particularly for less experienced clinicians. ConclusionThese results surpass existing benchmark models and demonstrate the potential of our approach to enhance diagnostic precision in clinically specific cases. By intelligently fusing multi-modal ultrasound data with attention-guided mechanisms, TUS-Net offers a reliable and interpretable tool that holds promise for improving the non-invasive diagnosis of atypical HCC in challenging LR-M liver nodules.

ObjectiveDiscriminating atypical hepatocellular carcinoma (HCC) from other malignancies in liver nodules classified as Liver Imaging Reporting and Data System category M (LR-M) remains a significant diagnostic challenge on conventional ultrasound examination. The LR-M category, originally intended to capture non-HCC malignancies, paradoxically contains up to 63% of atypical HCCs that deviate from classic enhancement patterns, leading to potential misdiagnosis and suboptimal treatment planning. While deep learning has shown promise in HCC diagnosis, most existing models rely exclusively on single-modality ultrasound, overlooking the diagnostic benefits of integrating complementary information from multiple imaging sources. To address this gap, we propose a novel attention-weighted tri-modal ultrasound network (TUS-Net) that integrates contrast-enhanced ultrasound (CEUS), B-mode ultrasound (BUS), and time-intensity curves (TICs) to improve diagnostic accuracy for these clinically challenging lesions. MethodsOur framework incorporates a three-dimensional convolutional neural network (C3D) backbone to extract spatiotemporal features from CEUS videos, capturing dynamic vascular patterns critical for lesion characterization. To effectively fuse complementary modalities, we introduce a dual-channel feature fusion module (DCFFM) that adaptively combines features from CEUS and BUS through channel-wise attention mechanisms, allowing the model to dynamically weigh the contribution of each modality based on diagnostic relevance. Additionally, we propose a temporal intensity feature fusion module (TIFFM) that leverages quantitative hemodynamic information from TICs to guide the model’s attention toward diagnostically critical temporal phases, such as arterial wash-in and portal venous washout. The model is further enhanced by automated lesion localization using YOLOX and class activation mapping for interpretability, ensuring that predictions align with clinically meaningful imaging features. ResultsEvaluated on a tri-modal ultrasound dataset comprising 161 patients with pathologically confirmed LR-M nodules (131 atypical HCC and 30 non-HCC malignancies), our model achieved an accuracy of 86.83%, a sensitivity of 92.50%, a specificity of 75.50%, and an AUC of 89.32% in screening atypical HCC. Compared to single-modality baselines, TUS-Net demonstrated superior specificity, a clinically critical metric given the higher risk associated with misclassifying non-HCC malignancies. Ablation studies confirmed the contribution of each module, with the full model outperforming both standard C3D and 3D ResNet backbones integrated with attention mechanisms. A reader study involving junior and senior radiologists further validated the clinical utility of AI assistance, showing consistent improvements in specificity and inter-reader consistency, particularly for less experienced clinicians. ConclusionThese results surpass existing benchmark models and demonstrate the potential of our approach to enhance diagnostic precision in clinically specific cases. By intelligently fusing multi-modal ultrasound data with attention-guided mechanisms, TUS-Net offers a reliable and interpretable tool that holds promise for improving the non-invasive diagnosis of atypical HCC in challenging LR-M liver nodules.

[摘 要] 目的：探讨干扰素刺激基因家族成员黏病毒抵抗蛋白2（MX2）在调控肿瘤细胞对呼肠孤病毒（Reo）溶瘤敏感性中的作用及其机制。方法：选取4株具有不同耐药特征的人源肿瘤细胞，通过CCK-8法评估其对Reo的溶瘤敏感性；通过转录组测序筛选出差异表达基因MX2，qPCR法及WB法验证MX2在4株人源肿瘤细胞中的表达；使用siRNA敲低溶瘤低敏感的COC1/DDP细胞中的MX2基因。在细胞感染Reo病毒后，通过CCK-8法检测细胞存活率；qPCR法检测细胞中Reo病毒S1基因表达；免疫荧光法检测细胞内Reo病毒蛋白的积累；半数组织培养感染剂量（TCID50）法测定病毒滴度；流式细胞术分别检测细胞内Reo病毒dsRNA、活性氧（ROS）水平以及细胞凋亡率；透射电镜观察细胞内质网形态变化并采用WB法检测内质网应激相关蛋白（JNK、p-JNK、eIF2α、p-eIF2α、CHOP、PERK）的表达。结果：在4株肿瘤细胞中，SKOV3细胞对Reo溶瘤作用高度敏感，而COC1/DDP、HuH-7SRB及SNU-398细胞均为溶瘤低敏感性。转录组测序结果显示，MX2在溶瘤低敏感肿瘤细胞中的表达水平显著高于溶瘤高敏感细胞（P < 0.01）；在溶瘤低敏感性的COC1/DDP细胞中，敲低MX2显著促进Reo病毒复制、诱导细胞凋亡增加，并升高细胞内活性氧水平（均P < 0.001）。透射电镜观察显示，敲低MX2的COC1/DDP细胞感染Reo病毒后出现内质网肿胀、扩张及断裂等典型内质网应激超微结构改变。WB结果显示，内质网应激关键标志物eIF2α/p-eIF2α、PERK、CHOP及凋亡相关调节蛋白JNK/p-JNK的表达均显著上调（P < 0.05或P < 0.01）。结论：肿瘤细胞对Reo的溶瘤敏感性与其细胞内MX2表达水平密切相关。敲低MX2可显著增强Reo在细胞内的复制，进而促进ROS积累，触发内质网应激并促进凋亡。病毒复制增加与细胞凋亡激活的双重作用，最终协同增强Reo的溶瘤作用。

ObjectiveTo explore the effect of oral sodium butyrate on skeletal muscle atrophy in CT26 tumor mice through the gut microbiota-skeletal muscle axis and its potential mechanism. MethodsSixty SPF BALB/c male mice aged 8 weeks were randomly divided into a normal control group (NC, n=18) and a ABX-depleted group (ABX, n=42). The ABX mice were pretreated with a quadruple antibiotic cocktail via oral gavage (0.2 ml per administration, once daily, 6 d per week, for 2 weeks), whereas NC received an equal volume of sterile water. The quadruple antibiotic cocktail consisted of metronidazole (1 g/L), vancomycin (0.5 g/L), ampicillin (1 g/L), and gentamicin (1 g/L). Following successful pretreatment, six mice from each group were randomly selected for gut microbiota sequencing analysis and designated as the Abx group and the NC0 group, respectively. Theremaining mice in ABX were subcutaneously inoculated in the dorsum with 0.2 ml of CT26 cell suspension (at a cell density of 1×10⁷/ml). Then these mice were randomly allocated into three subgroups: a control tumor bearing model group (0_NaB, n=12), a tumor-bearing model group receiving low-dose oral sodium butyrate (L_NaB, n=12), a tumor-bearing model group receiving high-dose oral sodium butyrate (H_NaB, n=12). And mice in NC were inoculated at the same site with 0.2 ml of normal saline. The administration dose for L_NaB was 0.3 g/(kg·d), that for H_NaB was 0.5 g/(kg·d), while NC and 0_NaB were given the same volume of normal saline (0.2ml per time, once daily, 6 d per week, for 4 weeks). The general condition of mice was monitored, and forelimb grip strength gastrocnemius muscle mass and its muscle fiber cross-sectional area were measured for each group. The structural changes in gut microbiota were assessed by 16S rRNA sequencing of cecal contents. Pathological alterations in the intestinal wall were examined via HE staining. Serum and gastrocnemius muscle levels of TNF‑α, IL-6, IL-1β, and LPS were quantified using ELISA. The protein expression of ZO-1 and occludin in the small intestine, as well as proteins associated with the TLR4/MyD88/NF-κB signaling pathway in the gastrocnemius muscle, were detected by Western blot analysis. Results(1) The alpha-diversity in Abx was significantly lower than that in NC0 (P<0.01), a significant decrease of the mass and muscle fiber cross-sectional area of the gastrocnemius (P<0.01), with the majority of gut microbiota being effectively depleted. (2) Compared with NC, the subcutaneous tumors of mice in 0_NaB were prominent, a significant increase of the mass and muscle fiber cross-sectional area of the gastrocnemius, accompanied by a significant decrease in body weight at the end of the 3th and 4th week (P<0.05), and a significant weakening of the forelimb grasping strength at the 5th and 6th week (P<0.01). Compared with 0_NaB, the tumor mass of mice in L_NaB and H_NaB showed a significant decreasing trend, and the grip strength of the forelimbs significantly increased at the 5th and 6th week (P<0.05, P<0.01). (3) Compared with 0_NaB, the Shannon and Observed species indices in α diversity of L_NaB and H_NaB were significantly increased (P<0.05). At the genus level, compared with 0_NaB, L_NaB exhibited a significant decrease in the relative abundance of Parasutterella (P< 0.01), while H_NaB showed significant reductions in the relative abundances of both Escherichia-Shigella and Parasutterella (P < 0.01). (4) Compared with 0_NaB, the small intestinal tissue structure in L_NaB and H_NaB was more intact, the infiltration of inflammatory cells was significantly reduced, and the capillaries were slightly dilated. The expression levels of ZO-1 and occludin proteins in L_NaB were significantly increased (P<0.01). (5) The LPS concentration in the gastrocnemius muscle and the protein expression levels of TLR4, MyD88, p-IκBα, and p-NF‑κB p65 in L_NaB and H_NaB were significantly lower than those in 0_NaB (P<0.05). The serum TNF‑α concentration in H_NaB and TNF-α concentration in the gastrocnemius muscle of the L_NaB and H_NaB were significantly lower than those in 0_NaB (P<0.05, P<0.01, P<0.01). ConclusionOral administration of NaB can improve gut microbiota α diversity, adjusting its composition, improving intestinal mucosal barrier function, reducing the LPS-induced pro-inflammatory response, and delaying skeletal muscle atrophy. The underlying mechanism may involve down regulation of TLR4/MyD88/NF-κB signaling in skeletal muscle.

Background: and Purpose Vertebrobasilar fusiform aneurysms (VBFAs) carry substantial morbidity and mortality, but optimal management for unruptured VBFAs remains unclear. We compared the safety and efficacy of conservative management (CM), stent-assisted coiling (SAC), and flow diverters (FDs) in patients with unruptured VBFAs, focusing on long-term prognosis. Methods: This study included data from a nationwide Chinese cohort of patients with vertebrobasilar dissecting aneurysms. Inverse probability of treatment weighting (IPTW) balanced confounders across groups. The primary outcome was poor prognosis (modified Rankin Scale score >2). Secondary outcomes included aneurysm rupture, ischemic stroke, compression symptoms, and VBFA-related deaths. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and sensitivity analyses were performed. Results: Among 1,115 patients with unruptured VBFAs, 838 (median age, 54 years; 655 men) were included. After IPTW, baseline characteristics were balanced. Median follow-up was 54 months. FD was associated with a lower risk of poor prognosis than CM (OR, 0.48 [95% CI, 0.30 to 0.77]; p=0.002), with no difference between CM and SAC. FD also reduced aneurysm rupture (OR, 0.20 [95% CI, 0.07 to 0.60]; p=0.004) and compression symptoms (OR, 0.30 [95% CI, 0.13 to 0.68]; p=0.004) versus CM. Time-to-event analyses further revealed significant differences in vertebral artery lesions and Type I–II VBFAs, whereas no significant differences were observed in basilar or vertebrobasilar junction lesions or in Type III–IV VBFAs. Conclusions Compared with CM, FD was associated with improved long-term outcomes in unruptured VBFAs, particularly in vertebral artery lesions and Type I–II VBFAs, although residual confounding cannot be excluded.

ObjectiveType I interferon (IFN-I) signaling is essential for antiviral innate immunity, yet its sustained or excessive activation contributes to the pathogenesis of several autoimmune diseases and interferonopathies, such as systemic lupus erythematosus and Aicardi-Goutières syndrome. Current strategies targeting this pathway, exemplified by JAK inhibitors, act mainly on downstream signal transduction and provide limited direct control over upstream IFN-I production, while also carrying the risk of broad immunosuppression. Phyllanthus emblica L. has long been used in traditional medicine for inflammatory disorders, but the bioactive constituent responsible for its regulation of IFN-I signaling and the underlying molecular mechanism have not been clearly defined. This study aimed to identify the active anti-inflammatory component of P. emblica and to characterize its mechanism of action on the IFN-I pathway in macrophages. MethodsActive components ofP. emblica and their candidate targets were screened by network pharmacology using the TCMSP and DrugBank databases (oral bioavailability≥30%, drug-likeness≥0.18) and intersected with inflammation-related genes retrieved from public databases. The predicted interaction between EGCG and IFN-I pathway proteins (TBK1, IRF3, STAT1) was evaluated by molecular docking, with BX795 and GSK8612 used as reference TBK1 inhibitors. Mechanistic experiments were performed in THP-1-derived macrophages and primary bone marrow-derived macrophages (BMDM). Upstream signaling was activated by transfection of the nucleic acid analogs poly(I∶C) and poly(dA∶dT) or by lipopolysaccharide (LPS) stimulation, whereas downstream signaling was activated by exogenous IFN-β. An siRNA-mediated TREX1 knockdown model was used to mimic endogenous nucleic acid-driven interferonopathy. Expression of IFN-β1 and interferon-stimulated genes (ISGs) was measured by RT-qPCR, protein phosphorylation by Western blot, and IFN-β secretion by ELISA. Cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) were used to probe the interactionbetween EGCG and IRF3. ResultsNetwork pharmacology identified (-)-epigallocatechin-3-gallate (EGCG) as a candidate IFN-I-suppressive constituent of P. emblica, with predicted binding to TBK1, IRF3, and STAT1. Molecular docking yielded binding energies of -9.2, -7.2, and -8.2 kcal/mol for TBK1, IRF3, and STAT1, respectively, indicating an affinity for TBK1 comparable to that of the reference inhibitors BX795 (-5.7 kcal/mol) and GSK8612 (-6.4 kcal/mol). EGCG suppressed IFN-β1 and ISG mRNA expression under poly (I∶C), poly (dA∶dT), and LPS stimulation in both THP-1 macrophages and BMDM. At the protein level, EGCG reduced the phosphorylation of TBK1 and IRF3 without affecting the levels of the upstream sensors cGAS and RIG-I, and lowered IFN-β secretion in a concentration-dependent manner. CETSA and DARTS showed that EGCG did not enhance the thermal stability or protease resistance of IRF3, indicating that its effect on IRF3 is indirect. Following IFN-β stimulation, prolonged EGCG treatment reduced STAT1 phosphorylation in a time-dependent manner without an apparent change in IRF9, and partially attenuated ISG transcription; this effect was not monotonicly concentration-dependent, and CXCL10 showed the most consistent suppression. In TREX1-knockdown cells, the elevated mRNA levels of ISG15, ISG56, and CXCL10 were reduced by EGCG. ConclusionEGCG suppresses IFN-I responses by concurrently inhibiting TBK1-IRF3-dependent IFN‑β production and JAK-STAT1-mediated downstream transcription. These in vitro findings provide a mechanistic basis for the anti-inflammatory use of P. emblica in traditional medicine and identify EGCG as a candidate for further evaluation in interferon-driven autoimmune disease models.

BACKGROUND:Previous studies by the research group have shown that core proteoglycan in Cornus Cervi Col la can enter the bone,promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells,and has a good repair effect on steroid-induced osteonecrosis of the femoral head.OBJECTIVE:To investigate the therapeutic effect and potential mechanism of Cornus Cervi Colla on steroid-induced osteonecrosis of the femoral head in rats by fecal non-targeted fecal metabolomics.METHODS:Thirty SD rats were randomly divided into three groups using a random number table method:the control group(n=10)was injected with normal saline into the right gluteal muscle(injected on the first 3 days of each week for 3 consecutive weeks),and was given pure water gavage(once a day for 6 consecutive weeks).The model group(n=10)was injected with methylprednisolone sodium succinate into the right gluteal muscle(injected on the first 3 days of each week for 3 consecutive weeks)to establish a steroid-induced osteonecrosis of the femoral head model,and was given pure water gavage(once a day for 6 consecutive weeks).The Cornus Cervi Co I la group(n=10)was also established with a steroid-induced osteonecrosis of the femoral head model,and was given Cornus Cervi Col la gavage(once a day for 6 consecutive weeks).After gavage,cecal feces and femoral heads were collected for fecal metabolomics analysis and bone tissue Micro-CT and hematoxylin-eosin staining,respectively.RESULTS AND CONCLUSION:(1)Metabolomics analysis results showed that there were 233 differential metabolites between the Cornus Cervi Col la and model groups,with 65 significantly differing and clearly annotated metabolites.Lipid and amino acid metabolites were significantly increased,with bile acids,sulfated steroids,ephedrine,hypoxanthine,betaine,L-carnitine,B-mouse bile acid,cytidine,4-pyridoxic acid,taurine,N-acetyl-d-glucosamine,and butyric acid being the most impacted(variable weight value VIP＞5).The metabolic pathways of taurine and hypotaurine were crucial in the metabolic regulatory network(pathway impact=0.428 57).(2)Micro-CT scanning results of bone tissue showed that the femoral heads of rats in the model group and the Cornus Cervi Col la group had different degrees of damage;the femoral head contour was irregular;the trabeculae in the subchondral bone of the femoral head were missing and disordered,and some cystic structures were visible.Compared with the model group,the degree of trabecular damage in the rats of the Cornus Cervi Colla group was milder.Hematoxylin-eosin staining results showed that the trabeculae in the subchondral bone of the femoral heads of rats in the model group and the Cornus Cervi Colla group were sparse or interrupted,and the empty bone lacuna rate and adipocyte invasion were increased.Compared with the model group,the empty bone lacuna rate and adipocyte invasion in the subchondral bone of the femoral heads of rats in the Cornus Cervi Colla group were reduced.(3)These results conclude that Cornus Cervi Colla potentially mitigates steroid-induced osteonecrosis of the femoral head through the metabolic processes involving taurine and associated pathways.

Objective:To explore the application effects of improved case-based learning (CBL) combined with hierarchical and progressive teaching in the standardized training of nuclear medicine resident physicians.Methods:A total of 43 resident physicians who rotated in the nuclear medicine base of our hospital between 2018 and 2023 were selected as the research subjects and divided into an experimental group ( n=22) and a control group ( n=21) according to the order of enrollment. The control group received the traditional teacher-centered teaching model and was divided into junior and senior subgroups according to the training years. The experimental group received the improved CBL combined with hierarchical and progressive teaching. First, through multidimensional evaluation (theoretical testing + standardized case analysis), the students were scientifically divided into preliminary, intermediate, and advanced levels. Subsequently, progressive teaching objectives were set for different levels, and real clinical cases embedded with hierarchical learning tasks were published. During the teaching process, a dynamic discussion mode combining homogeneous and heterogeneous grouping was adopted, and personalized guidance was provided by the teachers. Finally, dynamic hierarchical adjustment was implemented through process evaluation. After the training, the two groups were compared in terms of exit assessment performance (including professional basic theory and practical skills) and teaching satisfaction. Results:The total score of the exit assessment of the experimental group was higher than that of the control group [(86.90±6.78) vs. (75.09±8.45)], and the difference was statistically significant. In terms of practical skill assessment, the experimental group scored higher than the control group in modules such as imaging symptom description [(22.34±2.56) vs. (19.85±3.12)], localization diagnosis [(23.01±2.11) vs. (20.12±2.98)], qualitative diagnosis [(22.89±2.67 vs. 18.67±3.45)], and differential diagnosis [(21.56±2.89) vs. (17.23±3.78)] ( P<0.01). The teaching satisfaction survey showed that the satisfaction scores of the experimental group were higher than those of the control group in nine domains, including theoretical knowledge mastery, clinical thinking, image interpretation, and learning initiative ( P<0.05). Conclusions:The improved CBL combined with hierarchical and progressive teaching can effectively improve the exit assessment performance, clinical practice skills, and teaching satisfaction of nuclear medicine resident trainees, and is worthy of promotion.

The success of"New Medical Sciences"in higher education requires effective tools in evalua-ting students'performance in courses.Previously,we reported a teamwork(T),critique(C)and ap-preciation(A)(TCA)ideological and political model,a teaching model widely applied in Basic Medical courses.TCA is an abbreviation derived from Tricarboxylic Acid Cycle in Biochemistry as an analogy for nurturing the abilities of thinking and teamwork(T),critique(C)and appreciation(A),which hope-fully could provide students with moral norms for cognition,science and life.This paper further explores the tools to assess the educational outcomes of the TCA model,by which teachers can collect feedback and reflect on teaching quality and effectiveness.Addressing the challenges of individual differences in large classes,fragmented learning feedback,and the difficulty of measuring meta-cognition in educational evaluation,this study employs strategies of value-added assessment,matrix assessment and norm-transfer-able assessment to evaluate the TCA abilities from the aspects of thinking quality,thinking creativity,co-operation ability,iterative thinking,dialectical thinking and job responsibility.By modifying/using 18 e-valuation tools in Education and Psychology,we have established a rubric system composed of 30 primary indicators(with 11 newly designed,10 partly modified and 9 directly adopted),along with 49 secondary indicators and 98 tertiary indicators to enhance the feasibility of the evaluation process.This rubric sys-tem was applied to Biochemistry teaching among the five-year-program undergraduates at Air Force Medi-cal University.Specifically,thinking and teamwork are evaluated by creative works from"the magic bio-chemical-circle",while critiques are assessed in large classes under the guidance of basic and clinical teachers,coupled with appreciation measured by job responsibility in a task-driven virtual reality(VR)project.The results indicate that Biochemistry teaching not only accumulates knowledge in students,but also achieves the goals in nurturing values and cognition.The inclusion of creative performance evalua-tion,cooperative learning and clinical case studies,can enhance students'interpersonal skills,coopera-tion,quality of thinking,creative thinking,iterative thinking and dialectical thinking to varying degrees.TCA-based Biochemistry teaching has a long-lasting impact on character education,and is capable of in-ducing positive long-term changes in students'cognition and lifestyle.Taken together,with the help of this rubric system,teachers can promptly acknowledge the effectiveness of their teaching,thereby facilita-ting their teaching strategies.

BACKGROUND:Osteonecrosis is an orthopedic disease that severely limits joint function,with complex pathogenesis involving multiple risk factors.Cathepsins,as a class of enzymes that play a key role in bone metabolism,are closely related to the proliferation,differentiation of bone cells,and remodeling of the bone matrix.However,previous studies have mostly focused on descriptive analyses,lacking direct evidence of causal relationships.OBJECTIVE:To clarify the potential causal relationship between cathepsins and osteonecrosis and to explore their possible mechanisms by analyzing large-scale sample data from the FinnGen database.METHODS:We obtained osteonecrosis-related data from the FinnGen database,including R9(a total of 359 399 samples:1 385 cases and 358 014 controls)and R10 versions(a total of 392 580 samples:1 543 cases and 391 037 controls).Single nucleotide polymorphisms associated with nine cathepsins(cathepsin B,E,F,G,H,O,S,L2,and Z)were acquired from a previous study(3 301 individuals).Univariate Mendelian randomization,reverse univariate Mendelian randomization,and multivariate Mendelian randomization analyses were conducted using the inverse variance weighted method,MR-Egger method,weighted median method,simple mode method,and weighted mode method.Initially,Mendelian randomization analysis was performed using osteonecrosis data from R9.Additionally,sensitivity analyses were conducted using Cochran's Q test,MR-Egger intercept,MR-PRESSO global test,and leave-one-out analysis to check for horizontal pleiotropy and heterogeneity.Subsequently,a validation analysis study was carried out on the R10 dataset,and a meta-analysis was conducted to combine the two datasets to explore the joint effect.RESULTS AND CONCLUSION:Univariate Mendelian randomization analysis results showed that higher levels of cathepsin B were significantly associated with a reduced risk of osteonecrosis(inverse variance weighted:odds ratio(OR)=0.865,95％confidence interval(CI):0.762-0.982,P=0.025),and no reverse causal relationship was found between the nine cathepsins and osteonecrosis(P＞0.05).These associations were validated by meta-analysis.Multivariate analysis,using the nine cathepsins as covariates,revealed a reverse causal relationship between the levels of cathepsin Band the risk of osteonecrosis(inverse variance weighted:OR=0.8710,95％CI:0.761-0.997,P=0.045),consistent with the results before adjustment.Sensitivity analyses based on heterogeneity and horizontal pleiotropy suggested that the results were relatively robust.This study suggests that there is a causal relationship between high levels of cathepsin B and the reduced risk of osteonecrosis,and it may serve as a biomarker for osteonecrosis,providing new directions and insights for the diagnosis and treatment of osteonecrosis.Although this study is based on data analysis of European populations,these findings have important implications for Chinese biomedical research,especially in understanding disease mechanisms,developing biomarkers,and formulating treatment strategies.They also encourage similar studies conducted on Chinese populations to explore the impact of racial and genetic background differences on the occurrence of osteonecrosis.